Researchers Database

kato hirotomo

    InfectionandImmunityMedicalZoologyandParasitology Professor
Last Updated :2021/12/08

Researcher Information

URL

ORCID ID

Researcher ID

  • A-4820-2012

J-Global ID

Research Interests

  • sand fly   leishmaniasis   Leishmania   Trypanosoma   Chagas disease   Parasitology   salivary protein   zoonoses   vector biology   kissing bug   

Research Areas

  • Life sciences / Parasitology
  • Life sciences / Veterinary medicine

Academic & Professional Experience

  • 2020/04 - Today  Jichi Medical UniversityDepartment of Infection and ImunityHead of the Department of Infection and Imunity
  • 2016/04 - Today  Jichi Medical UniversityDivision of Medical Zoology, Department of Infection and ImmunityProfessor
  • 2011/04 - 2016/03  Hokkaido UniversityLaboratory of Parasitology, Graduate School of Veterinary MedicineAssociate Professor
  • 2002/04 - 2011/03  Yamaguchi UniversityLaboratory of Veterinary HygieneAssociate Professor
  • 2005/02 - 2006/01  NIAID, NIH, USALaboratory of Malaria and Vector Research, Vector Molecular Biology UnitGuest Researcher
  • 2001/04 - 2002/03  Tokyo Medical and Dental University医歯学総合研究科 免疫治療学教室博士研究員
  • 1999/04 - 2001/03  University of Alabama at BirminghamImmunobiology Vaccine CenterPostdoctoral Fellow

Education

  • 1995/04 - 1999/03  The University of Tokyo  Graduate School of Agriculture and Life Sciences  Department of Veterinary Medical Sciences
  • 1991/04 - 1995/03  The University of Tokyo  Faculty of Agriculture  Veterinary Medical Sciences Course
  • 1989/04 - 1991/03  The University of Tokyo  Natural Sciences II

Association Memberships

  • Japanese Society of Veterinary Parasitologists   THE JAPANESE SOCIETY OF VETERINARY SCIENCE   THE JAPANESE SOCIETY OF PARASITOLOGY   JAPANESE SOCIETY OF TROPICAL MEDICINE   THE JAPAN SOCIETY OF MEDICAL ENTOMOLOGY AND ZOOLOGY   

Published Papers

  • Yoshihisa Hashiguchi, Lenin V. Nieto, Nancy C. Villegas, Eduardo A. Gomez, Hirotomo Kato
    Archives of Medical and Clinical Research 01 (01) 1 - 15 2021/07 [Refereed][Invited]
  • Treepecth Prompetch, Akawat Chailorm, Saruda Tiwananthagorn, Nithidol Buranapim, Siriporn Okonogi, Hirotomo Kato, Wasan Katip, Raktham Mektrirat
    Pharmaceutics 13 (7) 2021/06 
    The present study aims to evaluate the efficacy of a novel drug delivery system of the modified rice hydrogel containing praziquantel (PZQ) against Philophthalmus gralli isolated from ostrich eyes and determine the toxicity of the preparation on chicken eye model. The parasiticidal activity of PZQ (0, 1, 10, and 100 µg/mL) was tested on P. gralli. The ophthalmic antiparasitic hydrogel was formulated with appropriate amount of PZQ and chemically modified rice gel. The parasitic morphology after exposure with the preparation was examined under scanning electron microscope (SEM). The anthelminthic efficacy of the preparation on motility and mortality of parasites was performed by visual inspection and vital dye staining. The ocular irritation of the preparation was evaluated for 21 days using standard avian model followed by OECD 405. The results demonstrated that the parasiticidal activity of PZQ against P. gralli appears to be in a concentration- and time-dependent manner. In addition, the concentration of PZQ 10 µg/mL (Chi squared test, p = 0.003) and exposure time for 24 h (log-rank test, p = 0.0004) is sufficient to kill parasites, when statistically compared to negative control group. Rice hydrogel containing a lethal concentration of 10 µg/mL PZQ was successfully prepared. The preparation illustrated good parasitic killing and motile inhibiting effect on P. gralli compared with PZQ 10 µg/mL and its control (p < 0.05). An appearance under SEM of non-viable parasite after being incubated with the preparation, showing parasitic deformity, was observed comparing with the viable parasite in 0.9% normal saline solution (NSS). Moreover, no irritation of chicken eyes was also observed. Our results contribute to understanding the efficacy and the safety of the rice hydrogel of PZQ which have a predictive value for controlling P. gralli on the animal eyes. However, the pharmacological application needs to be further investigated for the best possible therapeutic approach.
  • Hirotomo Kato, Chisato Seki, Makoto Kubo, Lizandro Gonzales-Cornejo, Abraham G Caceres
    PLoS neglected tropical diseases 15 (4) e0009352  2021/04 
    The natural infection of sand flies by Leishmania was investigated in Andean areas located between the Central and Eastern Cordilleras of northern Peru where cutaneous leishmaniasis caused by Leishmania (Viannia) peruviana is endemic. Sand flies were captured at five locations along the Utcubamba River in the Department of Amazonas, and morphologically identified under a microscope. Among 422 female sand flies dissected, the most dominant species was Pintomyia verrucarum (320 flies), followed by Pi. maranonensis (83 flies), Pi. robusta (13 flies), and Lutzomyia castanea (6 flies). Genetic analysis of sand flies from these areas together with those from other areas revealed that individuals of Pi. verrucarum were closely related regardless of morphological variation of their spermathecae. On the other hand, individuals of Pi. maranonensis collected in the study area were distant from those of other areas with genetic distances over the intraspecific level but mostly below the interspecific level, suggesting the unique characteristics of sand flies in this area. The natural infection of sand flies by flagellate parasites was detected mainly in the hindgut of each one of Pi. verrucarum and Pi. maranonensis. Both parasite species were identified as L. (V.) peruviana based on cytochrome b and mannose phosphate isomerase gene analyses. In addition, parasite species obtained from the lesion of a patient with cutaneous leishmaniasis in the study area in this period was identified as L. (V.) peruviana. These results strongly suggest that Pi. verrucarum and Pi. maranonensis are responsible for the transmission of L. (V.) peruviana in these areas. This is the first report of the natural infection of Pi. maranonensis by L. (V.) peruviana.
  • Mariwan M M Al-Bajalan, Sherko S Niranji, Sirwan M Al-Jaf, Hirotomo Kato
    Acta tropica 215 105807 - 105807 2021/03 
    Cutaneous leishmaniasis (CL) is transmitted by Phlebotomine sand fly vectors, among which Phlebotomus papatasi is prevalent in Western Asia, Northern Africa and Southern Europe, and it is known as a vector for Leishmania major parasite in the world. However, in Iraq, morphological studies showed that P. papatasi is a predominant sand fly species and hypothesised to transmit CL causing Leishmania species including L. major and L. tropica. Few studies have found Leishmania species in sand flies in mixed pools of samples in this country. Accurate identification of sand flies as vectors of Leishmania species is required in Iraq. The current study aims to identify sand fly species, using both morphological and molecular phylogenetic analyses, in a region where CL tends to be endemic. Furthermore, molecular phylogenetic analysis has also used to confirm Leishmania species in the sand fly samples collected in 11 villages between Diyala and Sulaymaniyah Provinces. For the first time, we have found L. major in three individual sand flies, one engorged (with fresh blood meal) and two non-engorged (without visible fresh blood meal) P. papatasi females in an area of CL outbreaks since 2014-till now due to civil wars and internal conflicts happen in the region. Further study should be performed on sand fly population and Leishmania reservoirs in this region.
  • Eri H Hayakawa, Hirotomo Kato, Glenn A Nardone, Jiro Usukura
    Parasitology international 80 102179 - 102179 2021/02 
    Plasmodium falciparum (P. falciparum) parasites still cause lethal infections worldwide, especially in Africa (https://www.who.int/publications/i/item/world-malaria-report-2019). During P. falciparum blood-stage infections in humans, low-density lipoprotein, high-density lipoprotein and cholesterol levels in the blood become low. Because P. falciparum lacks a de novo cholesterol synthesis pathway, it must import cholesterol from the surrounding environment. However, the origin of the cholesterol and how it is taken up by the parasite across the multiple membranes that surround it is not fully understood. To answer this, we used a cholesterol synthesis inhibiter (simvastatin), a cholesterol transport inhibitor (ezetimibe), and an activating ligand of the peroxisome proliferator-activated receptor α, called ciprofibrate, to investigate the effects of these agents on the intraerythrocytic growth of P. falciparum, both with and without HepG2 cells as the lipoprotein feeders. P. falciparum growth was inhibited in the presence of ezetimibe, but ezetimibe was not very effective at inhibiting P. falciparum growth when used in the co-culture system, unlike simvastatin, which strongly promoted parasite growth in this system. Ezetimibe is known to inhibit cholesterol absorption by blocking the activity of Niemann-Pick C1 like 1 (NPC1L1) protein, and simvastatin is known to enhance NPC1L1 expression in the human body's small intestine. Collectively, our results support the possibility that cholesterol import by P. falciparum involves hepatocytes, and cholesterol uptake into the parasite occurs via NPC1L1 protein or an NPC1L1 homolog during the erythrocytic stages of the P. falciparum lifecycle.
  • Mohammad Shahnaij, Mitsuhiro Iyori, Hiroaki Mizukami, Mayu Kajino, Iroha Yamagoshi, Intan Syafira, Yenni Yusuf, Ken Fujiwara, Daisuke S Yamamoto, Hirotomo Kato, Nobuhiko Ohno, Shigeto Yoshida
    Frontiers in immunology 12 612910 - 612910 2021 
    Hepatocyte infection by malaria sporozoites is a bottleneck in the life-cycle of Plasmodium spp. including P. falciparum, which causes the most lethal form of malaria. Therefore, developing an effective vaccine capable of inducing the strong humoral and cellular immune responses necessary to block the pre-erythrocytic stage has potential to overcome the spatiotemporal hindrances pertaining to parasite biology and hepatic microanatomy. We recently showed that when combined with a human adenovirus type 5 (AdHu5)-priming vaccine, adeno-associated virus serotype 1 (AAV1) is a potent booster malaria vaccine vector capable of inducing strong and long-lasting protective immune responses in a rodent malaria model. Here, we evaluated the protective efficacy of a hepatotropic virus, adeno-associated virus serotype 8 (AAV8), as a booster vector because it can deliver a transgene potently and rapidly to the liver, the organ malaria sporozoites initially infect and multiply in following sporozoite injection by the bite of an infected mosquito. We first generated an AAV8-vectored vaccine expressing P. falciparum circumsporozoite protein (PfCSP). Intravenous (i.v.) administration of AAV8-PfCSP to mice initially primed with AdHu5-PfCSP resulted in a hepatocyte transduction rate ~2.5 times above that seen with intramuscular (i.m.) administration. This immunization regimen provided a better protection rate (100% sterile protection) than that of the i.m. AdHu5-prime/i.m. AAV8-boost regimen (60%, p < 0.05), i.m. AdHu5-prime/i.v. AAV1-boost (78%), or i.m. AdHu5-prime/i.m. AAV1-boost (80%) against challenge with transgenic PfCSP-expressing P. berghei sporozoites. Compared with the i.m. AdHu5-prime/i.v. AAV1-boost regimen, three other regimens induced higher levels of PfCSP-specific humoral immune responses. Importantly, a single i.v. dose of AAV8-PfCSP recruited CD8+ T cells, especially resident memory CD8+ T cells, in the liver. These data suggest that boost with i.v. AAV8-PfCSP can improve humoral and cellular immune responses in BALB/c mice. Therefore, this regimen holds great promise as a next-generation platform for the development of an effective malaria vaccine.
  • Hirotomo Kato, Abraham G Cáceres, Eduardo A Gomez, Ahmed Tabbabi, Daiki Mizushima, Daisuke S Yamamoto, Yoshihisa Hashiguchi
    Frontiers in cellular and infection microbiology 11 625001 - 625001 2021 
    Approximately 20 Leishmania species are known to cause cutaneous, mucocutaneous, and visceral disorders in humans. Identification of the causative species in infected individuals is important for appropriate treatment and a favorable prognosis because infecting species are known to be the major determinant of clinical manifestations and may affect treatments for leishmaniasis. Although Leishmania species have been conventionally identified by multilocus enzyme electrophoresis, genetic analysis targeting kinetoplast and nuclear DNA (kDNA and nDNA, respectively) is now widely used for this purpose. Recently, we conducted countrywide epidemiological studies of leishmaniasis in Ecuador and Peru to reveal prevalent species using PCR-RFLP targeting nDNA, and identified unknown hybrid parasites in these countries together with species reported previously. Furthermore, comparative analyses of kDNA and nDNA revealed the distribution of parasites with mismatches between these genes, representing the first report of mito-nuclear discordance in protozoa. The prevalence of an unexpectedly high rate (~10%) of genetically complex strains including hybrid strains, in conjunction with the observation of mito-nuclear discordance, suggests that genetic exchange may occur more frequently than previously thought in natural Leishmania populations. Hybrid Leishmania strains resulting from genetic exchanges are suggested to cause more severe clinical symptoms when compared with parental strains, and to have increased transmissibility by vectors of the parental parasite species. Therefore, it is important to clarify how such genetic exchange influences disease progression and transmissibility by sand flies in nature. In addition, our aim was to identify where and how the genetic exchange resulting in the formation of hybrid and mito-nuclear discordance occurs.
  • Sayoko Sumiyoshi, Shinichi Tanaka, Hirotomo Kato, Kohji Takagi, Takashi Minamisaka, Akira Noguchi, Takahiko Nakajima, Johji Imura
    Biomedical reports 14 (1) 6 - 6 2021/01 
    Histoplasmosis is a fungal infection caused by Histoplasma capsulatum (HC), which can occasionally be aggressive resulting in the formation of granulomatous lesions. These are usually located in the lungs; however, immunocompromised patients may occasionally develop disseminated lesions in other organs as well. Human immunodeficiency virus (HIV) primarily infects cells of the immune system expressing CD4 molecules. Not only does HIV multiply within these cells, but it can also kill them or otherwise cause loss of cellular function, leading to an immunocompromised state. As a result, in an immunocompromised patient, infection with HC can have serious implications, often the development of visceral histoplasmosis in different organs. Although several types of lesions are formed in HC-infected organs, it may be difficult to distinguish the causative organism from other pathogens based on morphology alone. The present case report describes the case of a 57-year-old woman, from South America, who may have been infected with HC >20 years previously, remaining asymptomatic over the years. She later developed a lesion in the duodenum associated with immunodeficiency caused by HIV infection. The differential diagnosis of this case was made on the basis of several specific morphological findings using histopathological analysis and molecular pathological techniques. The pathogenesis of characteristic lesions caused by HC in the presence of HIV infection was also reviewed.
  • Ahmed Tabbabi, Shinya Watanabe, Daiki Mizushima, Abraham G Caceres, Eduardo A Gomez, Daisuke S Yamamoto, Longzhu Cui, Yoshihisa Hashiguchi, Hirotomo Kato
    Microorganisms 9 (1) 2020/12 
    Differences in the gut microbial content of Lutzomyia (Lu.) ayacuchensis, a primary vector of Andean-type cutaneous leishmaniasis in Ecuador and Peru, may influence the susceptibility of these sand flies to infection by Leishmania. As a first step toward addressing this hypothesis, a comparative analysis of bacterial and fungal compositions from Lu. ayacuchensis populations with differential susceptibilities to Leishmania was performed. Bacterial 16S rRNA gene amplification and Illumina MiSeq sequencing approaches were used to characterize the bacterial composition in wild-caught populations from the Andean areas of Ecuador and southern Peru at which the sand fly species transmit Leishmania (Leishmania) mexicana and Leishmania (Viannia) peruviana, respectively, and a population from the northern Peruvian Andes at which the transmission of Leishmania by Lu. ayacuchensis has not been reported. In the present study, 59 genera were identified, 21 of which were widely identified and comprised more than 95% of all bacteria. Of the 21 dominant bacterial genera identified in the sand flies collected, 10 genera had never been detected in field sand flies. The Ecuador and southern Peru populations each comprised individuals of particular genera, while overlap was clearly observed between microbes isolated from different sites, such as the number of soil organisms. Similarly, Corynebacterium and Micrococcus were slightly more dominant bacterial genera in the southern Peru population, while Ochrobactrum was the most frequently isolated from other populations. On the other hand, fungi were only found in the southern Peru population and dominated by the Papiliotrema genus. These results suggest that variation in the insect gut microbiota may be elucidated by the ecological diversity of sand flies in Peru and Ecuador, which may influence susceptibility to Leishmania infection. The present study provides key insights for understanding the role of the microbiota during the course of L. (L.) mexicana and L. (V.) peruviana infections in this important vector.
  • Ahmed Tabbabi, Abraham G Cáceres, T Pershing Bustamante Chauca, Chisato Seki, Yanisa Choochartpong, Daiki Mizushima, Daisuke S Yamamoto, Yoshihisa Hashiguchi, Hirotomo Kato
    PLoS neglected tropical diseases 14 (10) e0008797  2020/10 
    Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mannose phosphate isomerase (mpi) gene was applied to 134 skin samples collected from patients with cutaneous leishmaniasis (CL) in Peru for identification of the infecting parasite at the species level, and the results were compared with those of cytochrome b (cyt b) gene sequencing obtained in previous studies. Although most results (121/134) including 4 hybrids of Leishmania (Viannia) braziliensis and L. (V.) peruviana corresponded to those obtained in the previous study, PCR-RFLP analyses revealed the distribution of putative hybrid strains between L. (V.) peruviana and L. (V.) lainsoni in two samples, which has never been reported. Moreover, parasite strains showing discordance between kinetoplast and nuclear genes (kDNA and nDNA), so-called mito-nuclear discordance, were identified in 11 samples. Of these, six strains had the kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) guyanensis, and three strains had the kDNAs of L. (V.) shawi and nDNAs of L. (V.) braziliensis. The rest were identified as mito-nuclear discordance strains having kDNAs of L. (V.) braziliensis or L. (V.) peruviana and nDNAs of L. (V.) lainsoni, and kDNAs of L. (V.) lainsoni and nDNAs of L. (V.) braziliensis. The results demonstrate that Leishmania strains in Peru are genetically more complex than previously considered.
  • Daiki Mizushima, Ahmed Tabbabi, Daisuke S Yamamoto, Le Trung Kien, Hirotomo Kato
    Acta tropica 210 105473 - 105473 2020/10 [Refereed][Not invited]
     
    Salivary gland transcriptome analysis of the Asiatic Triatoma rubrofasciata was performed by high-throughput RNA sequencing. This analysis showed that the majority of reads accounting for 85.38% FPKM (fragments per kilobase of exon per million mapped fragments) were mapped with a secreted class. Of these, the most abundant subclass accounting for 89.27% FPKM was the lipocalin family. In the lipocalin family, the most dominant molecules making up 70.49% FPKM were homologues of procalin, a major allergen identified from T. protracta saliva, suggesting an important role in blood-sucking of T. rubrofasciata. Other lipocalins showed similarities to pallidipin and triplatin, inhibitors of collagen-induced platelet aggregation identified from T. pallidipennis and T. infestans, respectively, Td38 from T. dimidiata with unknown function, triatin-like lipocalin with unknown function, and triafestin, an inhibitor of the activation of the kallikrein-kinin system, identified from T. infestans saliva. Other than lipocalin family proteins, homologues of antigen-5 (3.38% FPKM), Kazal-type serine protease inhibitor (1.36% FPKM), inositol polyphosphate 5-phosphatase (1.32% FPKM), and apyrase/5'-nucleotidase (0.64% FPKM) were identified as abundant molecules in T. rubrofasciata saliva. Through this study, de novo assembly of 42,580,822 trimmed reads generated 35,781 trinity transcripts, and a total of 1,272 coding sequences for the secreted class were deposited in GenBank. The results provide further insights into the evolution of salivary components in blood-sucking arthropods.
  • Manuel Calvopina, Sara Jijon, Esteban Serrano, Hirotomo Kato
    The American journal of tropical medicine and hygiene 103 (2) 752 - 755 2020/08 [Refereed][Not invited]
     
    An 88-year-old man with mutilating mucosal leishmaniasis (ML) involving septal perforation, with granulomas in the pharynx and larynx, was treated with oral miltefosine, 50 mg three times/day for 28 days. Miltefosine, an antineoplastic agent, is considered an alternative option for the treatment of ML, showing efficacies of 75-92% in Bolivia, Brazil, and Argentina. The patient denied having previous cutaneous (CL) leishmaniasis, and no CL lesions were recognized by physical examination. Parasites obtained from mucosal lesions were identified by cytochrome b gene sequencing as Leishmania guyanensis. Clinical cure was observed 2 months posttreatment, and no evidence of reactivation was observed in the 3-year follow-up. Adverse effects such as nausea, loss of appetite, and epigastric pain were experienced during treatment with miltefosine. There is a need for improved access to miltefosine in leishmaniasis-endemic areas of Latin America and a greater awareness of ML and its treatment among physicians working in endemic countries.
  • Daiki Mizushima, Ahmed Tabbabi, Daisuke S Yamamoto, Le Trung Kien, Hirotomo Kato
    Data in brief 30 105647 - 105647 2020/06 [Refereed][Not invited]
     
    The dataset in this report is related to the research article entitled: "Salivary gland transcriptome of the Asiatic Triatoma rubrofasciata" [1]. Lipocalin family proteins were identified as the dominant component in T. rubrofasciata saliva, and phylogenetic analysis of the salivary lipocalins resulted in the formation of five major clades (clade I-V). For further characterization, each clade of T. rubrofasciata lipocalin was subjected to alignment and phylogenetic analyses together with homologous triatomine lipocalins: procalin, a major allergen in T. protracta saliva and its homologue Td04 from T. dimidiata (clade I), pallidipin and triplatin, inhibitors of collagen-induced platelet aggregation identified from T. pallidipennis and T. infestans, respectively, and their homologue Pc20 identified from Panstrongylus chinai (clade II), Td30 and Td38 from T. dimidiata with unknown functions (clade III), triatin-like salivary lipocalins, Pc58 and Pc226 identified from P. chinai and Td18 from T. dimidiata (clade IV), and triafestin, an inhibitor of the activation of the kallikrein-kinin system, identified from T. infestans saliva and its homologues, Td25 and Td40 from T. dimidiata and Pc64 from P. chinai (clade V).
  • Makoto Kubo, Ryuichi Nagashima, Mitsue Kurihara, Fumitaka Kawakami, Tatsunori Maekawa, Koji Eshima, Etsuro Ohta, Hirotomo Kato, Fumiya Obata
    International journal of molecular sciences 21 (5) 2020/03 [Refereed][Not invited]
     
    Leucine-rich repeat kinase 2 (LRRK2) is the causal molecule of familial Parkinson's disease. Although the characteristics of LRRK2 have gradually been revealed, its true physiological functions remain unknown. LRRK2 is highly expressed in immune cells such as B2 cells and macrophages, suggesting that it plays important roles in the immune system. In the present study, we investigate the roles of LRRK2 in the immune functions of dendritic cells (DCs). Bone marrow-derived DCs from both C57BL/6 wild-type (WT) and LRRK2 knockout (KO) mice were induced by culture with granulocyte/macrophage-colony stimulating factor (GM/CSF) in vitro. We observed the differentiation of DCs, the phosphorylation of the transcriptional factors NF-κB, Erk1/2, and p-38 after lipopolysaccharide (LPS) stimulation and antigen-presenting ability by flow cytometry. We also analyzed the production of inflammatory cytokines by ELISA. During the observation period, there was no difference in DC differentiation between WT and LRRK2-KO mice. After LPS stimulation, phosphorylation of NF-κB was significantly increased in DCs from the KO mice. Large amounts of inflammatory cytokines were produced by DCs from KO mice after both stimulation with LPS and infection with Leishmania. CD4+ T-cells isolated from antigen-immunized mice proliferated to a significantly greater degree upon coculture with antigen-stimulated DCs from KO mice than upon coculture with DCs from WT mice. These results suggest that LRRK2 may play important roles in signal transduction and antigen presentation by DCs.
  • Yoshihisa Hashiguchi, Eduardo A Gomez, Lenin N Velez, Nancy V Villegas, Makoto Kubo, Tatsuyuki Mimori, Kazue Hashiguchi, Hirotomo Kato
    Acta tropica 203 105287 - 105287 0001-706X 2020/03 [Refereed][Not invited]
     
    By employing protected human bait landing and modified Shannon light trap, a total of 1924 phlebotomine sand fly Lutzomyia spp. were captured in an area from which L. (V.) guyanensis was reported as the causative parasite of cutaneous leishmaniasis (CL). The sand flies captured alive were dissected and identified at species level, based mainly on their spermathecae. At the same time, the sand flies dissected were searched for the Leishmania parasites by microscopic-test, and later on by PCR-test. No positive sand flies were detected by both tests, while considerable numbers of anthropophilic sand fly species of the genus Lutzomyia were observed as probable vectors of the Leishmania parasite in the areas. Those were eight species, Lu. robusta, Lu. trapidoi, Lu. maranonensis, Lu. gomezi, Lu. shannoni, Lu. migonei, Lu. punctigeniculata and Lu. spathotrichia. Among them, the first two species Lu. robusta and Lu. trapidoi were most dominant, suggesting probable vectors of the Leishmania parasite prevailing in the area. Lu. punctigeniculata and Lu. spathotrichia were for the first time recorded for the Manabí province, Ecuador. These findings provide basic information useful for future planning of the control and management of the disease in the areas, though further study to incriminate the vector sand fly remains.
  • Yoshihisa Hashiguchi, Kazue Hashiguchi, Flavio C Zambrano, Francisco D Parraga, Viriginia P Martillo, Edison X Torres, Lenin N Velez, Nancy V Villegas, Eduardo A Gomez, Hirotomo Kato
    Acta tropica 203 105321 - 105321 0001-706X 2020/03 [Refereed][Not invited]
     
    To elucidate the transmission mode of Andean cutaneous leishmaniasis (Andean-CL), natural Leishmania infection and biting activity of sand flies were tested in a selected sylvatic focus of the endemic area of the Ecuadorian Andes. Monthly sand fly collections and dissections were conducted during 12 months from July 2018 to June 2019. The Leishmania positive specimens/slides with innumerable amounts of actively mobile flagellates made us easy to detect positive sand flies. The promastigotes observed located in the anterior and posterior midgut, without the hindgut localization. The parasite isolated was identified as L. (L.) mexicana by cytochrome b gene analysis. No other Leishmania or flagellate species parasitic in sand flies was observed in the area. Only Lu. ayacuchensis was caught throughout. Monthly microscopic examination of Lu. ayacuchensis revealed 0.75-8.33% of natural L. (L.) mexicana infection rates. Higher Leishmania infection months were present at the end of the wet season of the Andes, while higher sand fly numbers occurred during the dry season. Diurnal biting (blood meal seeking) activity of sand flies started around 17:30 before sunset, increased between 18:00 and 19:30, and thereafter decreased drastically probably because of low temperature (15-18 °C) in the area. The results provide information important for the planning of vector control strategy and management of the disease in the Andean-CL endemic area of Ecuador.
  • Chukwunonso O Nzelu, Hirotomo Kato, Nathan C Peters
    PLoS neglected tropical diseases 13 (11) e0007698  1935-2727 2019/11 [Refereed][Not invited]
     
    Leishmaniasis, caused by protozoan parasites of the Leishmania genus, represents an important health problem in many regions of the world. Lack of effective point-of-care (POC) diagnostic tests applicable in resources-limited endemic areas is a critical barrier to effective treatment and control of leishmaniasis. The development of the loop-mediated isothermal amplification (LAMP) assay has provided a new tool towards the development of a POC diagnostic test based on the amplification of pathogen DNA. LAMP does not require a thermocycler, is relatively inexpensive, and is simple to perform with high amplification sensitivity and specificity. In this review, we discuss the current technical developments, applications, diagnostic performance, challenges, and future of LAMP for molecular diagnosis and surveillance of Leishmania parasites. Studies employing the LAMP assay to diagnose human leishmaniasis have reported sensitivities of 80% to 100% and specificities of 94% to 100%. These observations suggest that LAMP offers a good molecular POC technique for the diagnosis of leishmaniasis and is also readily applicable to screening at-risk populations and vector sand flies for Leishmania infection in endemic areas.
  • Palm-size and one-inch gel electrophoretic device for reliable and field-applicable analysis of recombinase polymerase amplification.
    Rathore H, Biyani R, Kato H, Takamura Y, Biyani M
    Analytical Methods 11 4969 - 4976 2019/09 [Refereed][Not invited]
  • Daisuke S Yamamoto, Megumi Sumitani, Katsumi Kasashima, Hideki Sezutsu, Hiroyuki Matsuoka, Hirotomo Kato
    Scientific reports 9 (1) 8160 - 8160 2019/06 [Refereed][Not invited]
     
    Conditional cell death systems are useful for various aspects of basic science with a wide range of applications, including genetic pest control. We recently demonstrated that expression of the mammalian pro-apoptotic factor, B-cell leukaemia/lymphoma 2-associated X protein (Bax), can induce apoptosis in specific tissues by using tissue specific promoters in silkworm and mosquito. Here, we newly identified a functional promoter in the Asian malaria vector, Anopheles stephensi, which enables gene expression specifically in the testis. We produced a transgenic mosquito line that expresses mouse Bax under the control of this testis-specific promoter. Transgenic mosquito males exhibited aberrant testes without functional sperm and complete sterility, whereas transgenic females maintained normal fecundity. Despite their abnormal testes, the transgenic males maintained normal function of male accessory glands and typical mating behaviour. As a result of mating with these males, females showed refractoriness to further mating. These results suggest that transgenic males induce female sterility via mating. The mosquito is one of the most important disease vectors, and the control of their population benefits global public health. Thus, this Bax-mediated synthetic male-specific sterilization system could be applied to population control of mosquitoes.
  • Hirotomo Kato, Abraham G Cáceres, Chisato Seki, Carmen Rosa Silupu García, Carlos Holguín Mauricci, Salvadora Concepción Castro Martínez, Dafne Moreno Paico, Josefa Leila Castro Muniz, Lucinda Doriz Troyes Rivera, Zoila Isabel Villegas Briones, Silvia Guerrero Quincho, Guísela Lucy Sulca Jayo, Edwin Tineo Villafuerte, Carlos Manrique de Lara Estrada, Fernando Rafael Arias, Fredy Santiago Passara, Nancy Ruelas Llerena, Makoto Kubo, Ahmed Tabbabi, Daisuke S Yamamoto, Yoshihisa Hashiguchi
    PLoS neglected tropical diseases 13 (6) e0007496  1935-2727 2019/06 [Refereed][Not invited]
     
    To obtain further insight into geographic distribution of Leishmania species in Peru, a countrywide survey, including central to southern rainforest areas where information on causative parasite species is limited, was performed based on cytochrome b (cyt b) and mannose phosphate isomerase (mpi) gene analyses. A total of 262 clinical samples were collected from patients suspected of cutaneous leishmaniasis (CL) in 28 provinces of 13 departments, of which 99 samples were impregnated on FTA (Flinders Technology Associates) cards and 163 samples were Giemsa-stained smears. Leishmania species were successfully identified in 83 (83.8%) of FTA-spotted samples and 59 (36.2%) of Giemsa-stained smear samples. Among the 142 samples identified, the most dominant species was Leishmania (Viannia) braziliensis (47.2%), followed by L. (V.) peruviana (26.1%), and others were L. (V.) guyanensis, L. (V.) lainsoni, L. (V.) shawi, a hybrid of L. (V.) braziliensis and L. (V.) peruviana, and Leishmania (Leishmania) amazonensis. Besides the present epidemiological observations, the current study provided the following findings: 1) A hybrid of L. (V.) braziliensis and L. (V.) peruviana is present outside the Department of Huanuco, the only place reported, 2) Many cases of CL due to L. (V.) lainsoni, an uncommon causative species in Peru, were observed, and 3) L. (V.) shawi is widely circulating in southern Amazonian areas in Peru.
  • Hirotomo Kato, Eduardo A Gomez, Chisato Seki, Hayato Furumoto, Luiggi Martini-Robles, Jenny Muzzio, Manuel Calvopiña, Lenin Velez, Makoto Kubo, Ahmed Tabbabi, Daisuke S Yamamoto, Yoshihisa Hashiguchi
    PLoS neglected tropical diseases 13 (5) e0007403  1935-2727 2019/05 [Refereed][Not invited]
     
    PCR-Restriction Fragment Length Polymorphism (RFLP) analyses targeting multiple nuclear genes were established for the simple and practical identification of Leishmania species without using expensive equipment. This method was applied to 92 clinical samples collected at 33 sites in 14 provinces of Ecuador, which have been identified at the species level by the kinetoplast cytochrome b (cyt b) gene sequence analysis, and the results obtained by the two analyses were compared. Although most results corresponded between the two analyses, PCR-RFLP analyses revealed distribution of hybrid strains between Leishmania (Viannia) guyanensis and L. (V.) braziliensis and between L. (V.) guyanensis and L. (V.) panamensis, of which the latter was firstly identified in Ecuador. Moreover, unexpected parasite strains having the kinetoplast cyt b gene of L. (V.) braziliensis and nuclear genes of L. (V.) guyanensis, L. (V.) panamensis, or a hybrid between L. (V.) guyanensis and L. (V.) panamensis were identified. This is the first report of the distribution of a protozoan parasite having mismatches between kinetoplast and nuclear genes, known as mito-nuclear discordance. The result demonstrated that genetically complex Leishmania strains are present in Ecuador. Since genetic exchanges such as hybrid formation were suggested to cause higher pathogenicity in Leishmania and may be transmitted by more species of sand flies, further country-wide epidemiological studies on clinical symptoms, as well as transmissible vectors, will be necessary.
  • Maria E Grillet, Juan V Hernández-Villena, Martin S Llewellyn, Alberto E Paniz-Mondolfi, Adriana Tami, Maria F Vincenti-Gonzalez, Marilianna Marquez, Adriana C Mogollon-Mendoza, Carlos E Hernandez-Pereira, Juan D Plaza-Morr, Gabriella Blohm, Mario J Grijalva, Jaime A Costales, Heather M Ferguson, Philipp Schwabl, Luis E Hernandez-Castro, Poppy H L Lamberton, Daniel G Streicker, Daniel T Haydon, Michael A Miles, Alvaro Acosta-Serrano, Harry Acquattela, Maria G Basañez, Gustavo Benaim, Luis A Colmenares, Jan E Conn, Raul Espinoza, Hector Freilij, Mary C Graterol-Gil, Peter J Hotez, Hirotomo Kato, John A Lednicky, Clara E Martinez, Santiago Mas-Coma, J Glen Morris Jr, Juan C Navarro, Jose L Ramirez, Marlenes Rodriguez, Julio A Urbina, Leopoldo Villegas, Maikell J Segovia, Hernan J Carrasco, James L Crainey, Sergio L B Luz, Juan D Moreno, Oscar O Noya Gonzalez, Juan D Ramírez, Belkisyolé Alarcón-de Noya
    The Lancet. Infectious diseases 19 (5) e149-e161 - e161 1473-3099 2019/05 [Refereed][Not invited]
     
    In the past 5-10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children (<10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100 000 people and that of Zika virus is 2057 cases per 100 000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders.
  • Paniz Mondolfi AE, Colmenares Garmendia A, Mendoza Pérez Y, Hernández-Pereira CE, Medina C, Vargas F, Sandoval D, Agüero J, Román D, Forlano-Riera M, Salas Y, Peraza M, Romero P, Aldana F, Castillo T, Santeliz S, Perez G, Suarez-Alvarado MJ, Morales-Panza RJ, Kato H
    Acta tropica 191 252 - 260 0001-706X 2019/03 [Refereed][Not invited]
  • Eduardo A Gomez, Hirotomo Kato, Edison X Torres-Romero, Lenin N Velez, Nancy V Villegas, Virginia P Martillo, Flavio C Zambrano, Makoto Kubo, Kazue Hashiguchi, Yoshihisa Hashiguchi
    Acta tropica 185 204 - 211 1873-6254 2018/09 [Refereed][Not invited]
     
    The current four year study was undertaken to investigate the clinical and epidemiological features of Leishmania (Viannia) guyanensis infections in Valle Hermoso, Santo Domingo de Los Tsachilas province, north-central Pacific areas of Ecuador. A total of 155 parasitologically confirmed (Leishmania-amastigote-positive) clinical cases diagnosed at a rural health center during January 2014-December 2017 were analyzed thoroughly. Molecular characterization of the causative Leishmania parasites from different endemic sites within the study areas was performed by PCR amplification of cytochrome b (cyt b) sequencing. All the FTA-card and/or smear impregnated materials tested were characterized, and identified as L. (V.) guyanensis, without detecting any other Leishmania species. The following features were described: 1) the majority of patients were suffered from a single ulcer lesion (simple and mild to chronic), followed by multiple lesions, including recidiva cutis-"like" and Chiclero's ulcer-"like" clinical forms; 2) the majority (65.70%) of lesions were less than 10 mm in size, and distributed mainly on the upper body regions (arm, forearm, face, and neck including ear and head); 3) about 30% (29.68%) of the subjects tested were less than 10 years of age, strongly suggesting the intra- and/or peri-domestic transmission of the disease in the areas. The current clinico-epidemiological feature detected emphasizes the need for further such investigations of the L. (V.) guyanensis infections prevalent at different Pacific ecoregions of Ecuador, including Amazon regions.
  • Mariwan M M Al-Bajalan, Sirwan M A Al-Jaf, Sherko S Niranji, Dler R Abdulkareem, Khudhair K Al-Kayali, Hirotomo Kato
    PLoS neglected tropical diseases 12 (3) e0006255  1935-2735 2018/03 [Refereed][Not invited]
     
    BACKGROUND: Cutaneous leishmaniasis (CL) is a neglected worldwide, zoonotic, vector-borne, tropical disease that is a threat to public health. This threat may spread from endemic to non-endemic areas. Current research has exploited epidemiological, molecular and phylogenetical studies to determine the danger of an outbreak of CL in the borderline area between northern and central Iraq from 2014-2017. METHODOLOGY/PRINCIPAL FINDINGS: For the first time, using sequence analysis of the cytochrome b gene, the occurrence of CL in the borderline area between northern and central Iraq was confirmed to be due to Leishmania major. The phylogenetic analysis indicated that it was closely related to the L. major MRHO/IR/75/ER strain in Iran. CONCLUSIONS AND SIGNIFICANCE: In conclusion, the genotype confirmation of the L. major strain will improve our understanding of the epidemiology of the disease. This is important for facilitating control programs to prevent the further spread of CL. Furthermore, this area could be considered as a model for further research on the risk of global CL epidemics in other non-endemic countries where both reservoir hosts and sandfly vectors are present.
  • Mariwan M M Al-Bajalan, Sherko S Niranji, Sirwan M A Al-Jaf, Hirotomo Kato
    Parasitology research 117 (2) 585 - 590 1432-1955 2018/02 [Refereed][Not invited]
     
    Canine leishmaniasis (CanL) caused by Leishmania infantum (L. infantum) is considered as a zoonotic disease and within the last few decades, studies have identified the parasite as a major causative agent of human visceral leishmaniasis. However, in dogs, few recent studies have determined L. major as a cause of cutaneous manifestations and L. tropica as an etiological agent for cutaneous lesions involving mucosa. Interestingly, current study has found canine cutaneous lesions with mucosal involvement in a dog diagnosed with L. major, for the first time, in a focused area of human cutaneous leishmaniasis (CL) in the borderline between northern and central Iraq. Both molecular and phylogenetic studies showed that the dog L. major strain is closely related to that previously isolated from human CL in the same area. Moreover, serological study using rK39 identified IgG response against Leishmania, and the histological finding revealed the infiltration of inflammatory cells around the infection sites. These data will broaden our knowledge about CanL concerning the appearance of cutaneous clinical manifestations with mucocutaneous lesions caused by L. major. Further study on other animal reservoirs and vectors will shed the light on the epidemiology of this disease.
  • Yoshihisa Hashiguchi, Eduardo A Gomez L, Abraham G Cáceres, Lenin N Velez, Nancy V Villegas, Kazue Hashiguchi, Tatsuyuki Mimori, Hiroshi Uezato, Hirotomo Kato
    Acta tropica 178 264 - 275 1873-6254 2018/02 [Refereed][Not invited]
     
    The vector Lutzomyia sand flies and reservoir host mammals of the Leishmania parasites, causing the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador were thoroughly reviewed, performing a survey of literatures including our unpublished data. The Peruvian L. (V.) peruviana, a principal Leishmania species causing Andean-CL in Peru, possessed three Lutzomyia species, Lu. peruensis, Lu. verrucarum and Lu. ayacuchensis as vectors, while the Ecuadorian L. (L.) mexicana parasite possessed only one species Lu. ayacuchensis as the vector. Among these, the Ecuadorian showed a markedly higher rate of natural Leishmania infections. However, the monthly and diurnal biting activities were mostly similar among these vector species was in both countries, and the higher rates of infection (transmission) reported, corresponded to sand fly's higher monthly-activity season (rainy season). The Lu. tejadai sand fly participated as a vector of a hybrid parasite of L. (V.) braziliensis/L. (V.) peruviana in the Peruvian Andes. Dogs were considered to be principal reservoir hosts of the L. (V.) peruviana and L. (L.) mexicana parasites in both countries, followed by other sylvatic mammals such as Phyllotis andium, Didelphis albiventris and Akodon sp. in Peru, and Rattus rattus in Ecuador, but information on the reservoir hosts/mammals was extremely poor in both countries. Thus, the Peruvian disease form demonstrated more complicated transmission dynamics than the Ecuadorian. A brief review was also given to the control of vector and reservoirs in the Andes areas. Such information is crucial for future development of the control strategies of the disease.
  • Yoshihisa Hashiguchi, Eduardo A L Gomez, Abraham G Cáceres, Lenin N Velez, Nancy V Villegas, Kazue Hashiguchi, Tatsuyuki Mimori, Hiroshi Uezato, Hirotomo Kato
    Acta tropica 177 135 - 145 0001-706X 2018/01 [Refereed][Not invited]
     
    This study provides comprehensive information on the past and current status of the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador, mainly focusing on the causative Leishmania parasites and clinico-epidemiological features. Available information and data including our unpublished works were analyzed thoroughly. Endemic regions of the Andean-CL (uta) in Peru run from the north Piura/Cajamarca to the south Ayacucho at a wide range of the Pacific watersheds of the Andes through several departments, while in Ecuador those exist at limited and spotted areas in the country's mid-southwestern two provinces, Azuay and Chimborazo. The principal species of the genus Leishmania are completely different at subgenus level, L. (Viannia) peruviana in Peru, and L. (Leishmania) mexicana and L. (L.) major-like (infrequent occurrence) in Ecuador. The Peruvian uta is now prevalent in different age and sex groups, being not clearly defined as found in the past. The precise reasons are not known and should be elucidated further, though probable factors, such as emergence of other Leishmania parasites, non-immune peoples' migration into the areas, etc., were discussed briefly in the text. The Andean-CL cases in Ecuador are more rural than before, probably because of a rapid development of the Leishmania-positive communities and towns, and the change of life-styles of the inhabitants, including newly constructed houses and roads in the endemic areas. Such information is helpful for future management of the disease, not only for Leishmania-endemic areas in the Andes but also for other endemic areas.
  • Sarunya Tedlongthong, Nareerat Viseshakul, Hirotomo Kato, Supatra Areekit, Somchai Santiwatanakul, Kosum Chansiri
    ScienceAsia 43 (6) 354 - 361 1513-1874 2017/12 [Refereed][Not invited]
     
    Feline infectious anaemia is caused by a Gram-negative, uncultivable, cell wall-deficient, epierythrocytic parasitic bacteria known as feline haemoplasmas (FHM) in the genus Mycoplasma, namely, Mycoplasma haemofelis (Mhf), Candidatus M. haemominutum (CMhm), and Ca. M. turicensis (CMtc). Here, a loop-mediated isothermal amplification (LAMP) targeting the 16S rRNA gene combined with malachite green (MG) based colorimetric assay was developed for the detection of feline CMhm infection. The limit of detection was determined using a ten-fold serial dilution of recombinant plasmid DNA (from 108 to 1 copies). The result indicated that the LAMP-MG assay could detect as low as 264 copies corresponding to 264 organisms/μl of CMhm feline blood. Comparison between the LAMP-MG and standard polymerase chain reaction (PCR) surveying 105 clinical samples suggested that 17 and 15 samples were positive for CMhm, respectively. Validity of the LAMP-MG assay was assessed and calculated within 95% confidence intervals (CIs). The sensitivity, specificity, prevalence and accuracy were 100.0%, 97.8%, 14.3%, and 98.1%, respectively. The degree of agreement between LAMP-MG and standard PCR assays was 92.6%, with a κ coefficient of 1 (CI: 82.5-100.0%). This LAMP-MG colorimetric assay may be applicable as a rapid screening point-ofcare testing for feline CMhm, as well as for blood donors prior to blood transfusion by using unsophisticated equipment, such as a heating block or water bath. This technique could provide robust results, which are easily distinguished within 60 min after amplification.
  • Hirotomo Kato, Ryan C Jochim, Eduardo A Gomez, Shunsuke Tsunekawa, Jesus G Valenzuela, Yoshihisa Hashiguchi
    Data in brief 15 272 - 280 2352-3409 2017/12 [Refereed][Not invited]
     
    The dataset in this report is related to the research article with the title: "Salivary gland transcripts of the kissing bug, Panstrongylus chinai, a vector of Chagas disease" (Kato et al., 2017) [1]. Lipocalin family proteins were identified as the dominant component in P. chinai saliva, and phylogenetic analysis of the salivary lipocalins resulted in the formation of five major clades. For further characterization, each clade of P. chinai lipocalin was s alignment and phylogenetic analyses together with homologous triatomine lipocalins; pallidipin 2, an inhibitor of collagen-induced platelet aggregation identified from saliva of Triatoma pallidipennis (clade I), pallidipin-like salivary lipocalin from Triatoma dimidiata (clade II), salivary lipocalin from T. dimidiata (clade III), triatin-like salivary lipocalin identified in the saliva of T. dimidiata (clade IV), and lipocalin-like TiLipo37 from Triatoma infestans (clade V).
  • Suradej Siripattanapipong, Hirotomo Kato, Peerapan Tan-Ariya, Mathirut Mungthin, Saovanee Leelayoova
    The Journal of eukaryotic microbiology 64 (6) 820 - 828 1066-5234 2017/11 [Refereed][Not invited]
     
    Leishmania martiniquensis, a zoonotic hemoflagellate, is a causative agent of cutaneous (CL) and visceral leishmaniasis (VL) among humans and animals. This organism, first reported in Martinique Island, now has become an emerging infectious agent in Thailand. Symptomatic cases of L. martiniquensis infection among humans have continuously increased. In the meantime, asymptomatic infection of this novel species has seriously created national public health awareness and concern to prevent and control disease transmission. The unsuccessful serological test using the commercial rK39 dipstick based on antigen from Leishmania donovani to detect the antibodies against VL among infected Thai patients has encouraged us to further explore a new sensitive and specific antigenic epitope. In this study, we determined the sequences and expressed recombinant proteins of kinesin 39 (k39), heat shock protein 70 (hsp70), heat shock protein 83 (hsp83), and glycoprotein 63 (gp63) of L. martiniquensis to evaluate the diagnostic efficiency to detect antibodies against L. martiniquensis in patient sera. The preliminary results from western blot analysis have suggested that K39 is the most sensitive recombinant protein to detect L. martiniquensis. Moreover, this recombinant protein reacts with antibodies against L. donovani and Leishmania infantum, making it a promising antigen for further development of a universal rapid diagnostic tool for VL.
  • Hirotomo Kato, Ryan C Jochim, Eduardo A Gomez, Shunsuke Tsunekawa, Jesus G Valenzuela, Yoshihisa Hashiguchi
    Acta tropica 174 122 - 129 0001-706X 2017/10 [Refereed][Not invited]
     
    The saliva of hematophagous arthropods injected during blood feeding contains potent pharmacologically active components to counteract the host hemostatic and inflammatory systems. In the present study, dominant salivary gland transcripts of Panstrongylus chinai, a vector of Chagas disease, were analyzed by sequencing randomly selected clones of the salivary gland cDNA library. This analysis showed that 56.5% of the isolated transcripts coded for putative secreted proteins, of which 73.7% coded for proteins belonging to the lipocalin family. The most abundant transcript of lipocalin family proteins was a homologue of pallidipin 2, an inhibitor of collagen-induced platelet aggregation of Triatoma pallidipennis. In addition, homologues of triafestin, an inhibitor of the kallikrein-kinin system of T. infestans, were identified as the dominant transcript. Other salivary transcripts encoding lipocalin family proteins had homology to triplatin (an inhibitor of platelet aggregation) and others with unknown function. Other than lipocalin family proteins, homologues of a Kazal-type serine protease inhibitor (putative anticoagulant), a hemolysin-like protein (unknown function), inositol polyphosphate 5-related protein (a regulator of membrane phosphoinositide), antigen 5-related protein (unknown function) and apyrase (platelet aggregation inhibitor) were identified.
  • Yoshihisa Hashiguchi, Lenin N Velez, Nancy V Villegas, Tatsuyuki Mimori, Eduardo A L Gomez, Hirotomo Kato
    Acta tropica 166 299 - 315 0001-706X 2017/02 [Refereed][Not invited]
     
    This article reviews current knowledge about leishmaniases in Ecuador, proceeding from 1920, when the first human case was described, to the present, mainly focusing on the recent research events published. Regarding basic situations, it appears that 23 of Ecuador's 24 provinces have leishmaniasis-case reports. The disease is one of the mandatory notification infectious diseases in the country since 2005. All the 21,305 cases notified to the Ministry of Public Health, during the period from 2001 through 2014, were said to involve different clinical features of cutaneous leishmaniasis (CL) but not visceral (VL). Eight Leishmania species, L. (Viannia) guyanensis, L. (V.) panamensis, L. (V.) braziliensis, L. (Leishmania) mexicana, L. (L.) amazonensis, L. (L.) major-like, L. (V.) naiffiand L. (V.) lainsoni were characterized. The last two species were most recently reported from the Ecuadorian Amazon regions. Of the 73 Ecuadorian Lutzomyia species (43 man-biting species) recorded, only four, Lu. trapidoi, Lu. gomezi, Lu. ayacuchensis, and Lu. tortura were incriminated as vectors of the Leishmania parasites. Current knowledge on the reservoir hosts of Leishmania in Ecuador is extremely poor. Recently, in Ecuador different kinds of molecular techniques were developed for diagnosis and mass screening of the disease, employing various materials derived from patients and sand fly vectors. These are PCR-RFLP, colorimetric FTA-LAMP etc. Brief comments and recommendations were also given, for future research and control of leishmaniases in Ecuador.
  • Saruda Tiwananthagorn, Hirotomo Kato, Ranchana Yeewa, Amontip Muengpan, Raxsina Polseela, Saovanee Leelayoova
    Memorias do Instituto Oswaldo Cruz 112 (2) 100 - 107 0074-0276 2017/02 [Refereed][Not invited]
     
    BACKGROUND: Leishmaniasis caused by Leishmania martiniquensis infection has been reported in human and domestic animals of Martinique Island, Germany, Switzerland, USA, Myanmar and Thailand. The peculiar clinical features of disseminated cutaneous and visceral forms co-existence render the urgent need of specific diagnostic tool to identify the natural sand fly vectors for effective prevention and control strategies. Loop-mediated isothermal amplification (LAMP) of 18S rRNA gene as well as polymerase chain reaction (PCR) of minicircle kinetoplast DNA gene (PCR-mkDNA) have never been applied to detect L. martiniquensis and L. siamensis in sand fly vectors. OBJECTIVE: The present study was aimed to validate malachite green-LAMP (MG-LAMP) and PCR-mkDNA techniques to detect L. martiniquensis in sand fly vectors, compared with the conventional PCR of internal transcribed spacer 1 (PCR-ITS1). METHODS: We compared the validity of LAMP of 18S rRNA gene and PCR-mkDNA, to PCR-ITS1 in simulation model of L. martiniquensis infection in Sergentomyia gemmea sand flies. Attributable to the sensitivity and specificity, PCR-mkDNA was consecutively applied to detect L. martiniquensis in 380 female sand fly individuals captured in the newly identified affected region of Lamphun Province, Thailand. FINDINGS AND MAIN CONCLUSIONS: Results showed that PCR-mkDNA could detect at least one promastigote per sand fly, which was 10-time superior to LAMP and PCR-ITS1. In addition, PCR-mkDNA was more specific, able to differentiate L. martiniquensis from other viscerotropic Leishmania species, such as L. siamensis, L. (L.) donovani, and L. (L.) infantum. Consecutively, mass screening of L. martiniquensis in 380 female sand fly individuals by PCR-mkDNA was implemented in a new affected area of Thailand where a patient with leishmaniasis/HIV co-infection resides; however Leishmania DNA was undetected. In conclusion, PCR-mkDNA is a promising tool for molecular mass screening of L. martiniquensis infection in outbreak areas where several species of Leishmania and sand flies co-exist.
  • Shirin Akter, Mohammad Zahangir Alam, Ryo Nakao, Golam Yasin, Hirotomo Kato, Ken Katakura
    The American journal of tropical medicine and hygiene 95 (4) 795 - 799 0002-9637 2016/10 [Refereed][Not invited]
     
    Visceral leishmaniasis (VL), or kala-azar, is mainly caused by two closely related Leishmania species, Leishmania infantum and Leishmania donovani Leishmania infantum is responsible for zoonotic VL, with dogs as the main reservoir host in the Mediterranean, the Middle East, Asia, and South America. In the Indian subcontinent, VL is caused by L. donovani and is considered anthroponotic, although the only known vector, the sand fly, is zoophilic in nature. The role of domestic and stray dogs in VL transmission is still unclear in this area. We screened 50 stray dogs from VL-endemic areas of Bangladesh for serological and molecular evidence of Leishmania infection. We detected anti-Leishmania antibodies in six (12%) dog serum samples using rK39 immunochromatographic tests. We observed Leishmania kinetoplast DNA in 10 (20%) buffy coat DNA samples by real-time polymerase chain reaction (PCR), five of which were positive based on internal transcribed spacer 1-PCR. A sequencing analysis of the amplified products confirmed that the parasitic DNA was derived from L. donovani Our findings support the hypothesis that stray dogs are an animal reservoir for L. donovani in this endemic region. Further studies are required to determine the precise role of dogs in the epidemiology of VL in Bangladesh.
  • Hirotomo Kato, Eduardo A. Gomez, Luiggi Martini-Robles, Jenny Muzzio, Lenin Velez, Manuel Calvopina, Daniel Romero-Alvarez, Tatsuyuki Mimori, Hiroshi Uezato, Yoshihisa Hashiguchi
    PLOS NEGLECTED TROPICAL DISEASES 10 (7) 1935-2735 2016/07 [Refereed][Not invited]
     
    A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.
  • Yu Koarashi, Abraham G Cáceres, Florencia Margarita Zúniga Saca, Elsa Elvira Palacios Flores, Adela Celis Trujillo, José Luis Abanto Alvares, Kumiko Yoshimatsu, Jiro Arikawa, Ken Katakura, Yoshihisa Hashiguchi, Hirotomo Kato
    Acta tropica 158 83 - 87 0001-706X 2016/06 [Refereed][Not invited]
     
    A PCR-Restriction Fragment Length Polymorphism (RFLP) targeting the mannose phosphate isomerase gene was established to differentiate Leishmania species distributed near the Department of Huanuco, Peru. The technique was applied to 267 DNA samples extracted from Giemsa-stained smears of cutaneous lesions taken from patients suspected for cutaneous leishmaniasis in the area, and the present status of causative Leishmania species was identified. Of 114 PCR-amplified samples, 22, 19, 24 and 49 samples were identified to be infected by Leishmania (Viannia) braziliensis, L. (V.) peruviana, L. (V.) guyanensis, and a hybrid of L. (V.) braziliensis/L. (V.) peruviana, respectively, and the validity of PCR-RFLP was confirmed by sequence analysis. Since PCR-RFLP is simple and rapid, the technique will be a useful tool for the epidemiological study of leishmaniasis.
  • Hirotomo Kato, Abdon E. Bone, Tatsuyuki Mimori, Kazue Hashiguchi, Gonzalo F. Shiguango, Silvio V. Gonzales, Lenin N. Velez, Angel G. Guevara, Eduardo A. Gomez, Yoshihisa Hashiguchi
    PLOS NEGLECTED TROPICAL DISEASES 10 (5) 1935-2735 2016/05 [Refereed][Not invited]
     
    An epidemiological study of leishmaniasis was performed in Amazonian areas of Ecuador since little information on the prevalent Leishmania and sand fly species responsible for the transmission is available. Of 33 clinical specimens from patients with cutaneous leishmaniasis (CL), causative parasites were identified in 25 samples based on cytochrome b gene analysis. As reported previously, Leishmania (Viannia) guyanensis and L. (V.) braziliensis were among the causative agents identified. In addition, L. (V.) lainsoni, for which infection is reported in Brazil, Bolivia, Peru, Suriname, and French Guiana, was identified in patients with CL from geographically separate areas in the Ecuadorian Amazon, corroborating the notion that L. (V.) lainsoni is widely distributed in South America. Sand flies were surveyed around the area where a patient with L. (V.) lainsoni was suspected to have been infected. However, natural infection of sand flies by L. (V.) lainsoni was not detected. Further extensive vector searches are necessary to define the transmission cycle of L. (V.) lainsoni in Ecuador.
  • Saw Bawm, Lat Lat Htun, Ni Ni Maw, Tin Ngwe, Yusuke Tosa, Tomoyuki Kon, Chiho Kaneko, Ryo Nakao, Tatsuya Sakurai, Hirotomo Kato, Ken Katakura
    Ticks and tick-borne diseases 7 (1) 204 - 207 1877-959X 2016/02 [Refereed][Not invited]
     
    Cattle babesiosis is one of the most important tick-borne diseases worldwide. The present study reports a molecular survey of Babesia infections in cattle in Myanmar. Nested PCR assays based on the Babesia bigemina apical membrane antigen-1 gene (AMA-1) and B. bovis rhoptry associated protein-1 gene (RAP-1) revealed that the overall percentage of B. bigemina and B. bovis infection were 9.8% (70/713) and 17.1% (122/713), respectively. A mixed infection was detected in 4.6% (33/713) of animals. Animals <1 year (OR=13.66, CI=5.15-36.26) and 1-5 years of age (OR=3.91, CI=1.50-10.17) were identified as potential risk factors for B. bigemina infection. For B. bovis infection, age <1 year (OR=3.06, CI=1.63-5.75) and 1-5 years (OR=2.08, CI=1.21-3.57), Friesian-Zebu crossbreeds (OR=2.04, CI=1.26-3.30) and grazing (OR=1.59, CI=1.06-2.38) were identified as potential risk factors. This is the first report on a nationwide survey of bovine Babesia infections in Myanmar, providing useful information for the management and control of the disease.
  • Hirotomo Kato, Abraham G. Caceres, Yoshihisa Hashiguchi
    PLOS NEGLECTED TROPICAL DISEASES 10 (1) 1935-2735 2016/01 [Refereed][Not invited]
     
    The natural infection of sand flies by Leishmania was examined in the Department of Huanuco of Peru, where cutaneous leishmaniasis caused by a hybrid of Leishmania (Viannia) braziliensis/L. (V.) peruviana is endemic. A total of 2,997 female sand flies were captured by CDC light traps and Shannon traps, of which 2,931 and 66 flies were identified as Lutzomyia tejadai and Lu fischeri, respectively. Using crude DNA extracted from individual sand flies as a template, Leishmania DNA was detected from one Lu. tejadai. The parasite species was identified as a hybrid of L. (V.) braziliensis/L. (V.) peruviana on the basis of cytochrome b and mannose phosphate isomerase gene analyses. The result suggested that Lu. tejadai is responsible for the transmission of the hybrid Leishmania circulating in this area.
  • Yoshihisa Hashiguchi, Eduardo L Gomez, Hirotomo Kato, Luiggi R Martini, Lenin N Velez, Hiroshi Uezato
    Tropical medicine and health 44 (1) 2 - 2 1349-4147 2016 [Refereed][Not invited]
     
    BACKGROUND: In Ecuador, cutaneous leishmaniasis (CL) is prevalent countrywide, but only one case of diffuse-CL and two cases of disseminated-CL were experienced during our research activities more than 30 years from 1982 to date. These three patients suffered from multiple lesions distributed at a wide range of the body surface, revealing difficulty to clinically differentiate each other. METHODS: There is a considerable confusion of the use and/or differentiation of the terminologies (terms) between the two disease forms, diffuse-CL and disseminated-CL. One of the aims of the present study is to clarify the difference between the two disease forms, mainly based on the cases experienced in Ecuador. RESULTS: The disseminated-CL case newly reported here was clinically very similar to the diffuse-CL case, but the former showed the following marked differences from the latter: (1) the organisms isolated were identified as the parasites of Leishmania (Viannia) guyanensis/panamensis, which are also known as the causative agents of disseminated-CL in different endemic countries of the New World; (2) the patient was sensitive against antimonials; and (3) mucosal involvement was observed, which is never observed in diffuse-CL. CONCLUSIONS: In the text, three clinical cases, one diffuse-CL and two disseminated-CL, were presented. Furthermore, a bibliographic comparison of the features between the two disease forms was made, and a brief comment was also given.
  • Chukwunonso O Nzelu, Abraham G Cáceres, Silvia Guerrero-Quincho, Edwin Tineo-Villafuerte, Luis Rodriquez-Delfin, Tatsuyuki Mimori, Hiroshi Uezato, Ken Katakura, Eduardo A Gomez, Angel G Guevara, Yoshihisa Hashiguchi, Hirotomo Kato
    Acta tropica 153 116 - 9 0001-706X 2016/01 [Refereed][Not invited]
     
    Leishmaniasis remains one of the world's most neglected diseases, and early detection of the infectious agent, especially in developing countries, will require a simple and rapid test. In this study, we established a quick, one-step, single-tube, highly sensitive loop-mediated isothermal amplification (LAMP) assay for rapid detection of Leishmania DNA from tissue materials spotted on an FTA card. An FTA-LAMP with pre-added malachite green was performed at 64°C for 60min using a heating block and/or water bath and DNA amplification was detected immediately after incubation. The LAMP assay had high detection sensitivity down to a level of 0.01 parasites per μl. The field- and clinic-applicability of the colorimetric FTA-LAMP assay was demonstrated with 122 clinical samples collected from patients suspected of having cutaneous leishmaniasis in Peru, from which 71 positives were detected. The LAMP assay in combination with an FTA card described here is rapid and sensitive, as well as simple to perform, and has great potential usefulness for diagnosis and surveillance of leishmaniasis in endemic areas.
  • Eglys González-Marcano, Hirotomo Kato, Juan Luis Concepción, María Elizabeth Márquez, Alberto Paniz Mondolfi
    Methods in molecular biology (Clifton, N.J.) 1392 113 - 24 1064-3745 2016 [Refereed][Not invited]
     
    Leishmaniasis is an infectious disease caused by protozoan parasites of the genus Leishmania which are transmitted to humans through bites of infected sand flies. The variable clinical manifestations and the evolution of the disease are determined by the infecting species. Recognition at a species level is of utmost importance since this greatly impacts therapy decision making as well as predicts outcome for the disease. This chapter describes the application of polymerase chain reaction (PCR) in the detection of Leishmania parasites across the disease spectrum, including protocols for sample collection and transportation, genomic material extraction, and target amplification methods with special emphasis on PCR amplification of the cytochrome b gene for Leishmania spp. species identification.
  • Hector R Olalla, Lenin N Velez, Hirotomo Kato, Kazue Hashiguchi, Abraham G Caceres, Eduardo A Gomez, Flavio C Zambrano, Daniel A Romero-Álvarez, Angel G Guevara, Yoshihisa Hashiguchi
    Acta tropica 146 119 - 26 0001-706X 2015/06 [Refereed][Not invited]
     
    An analysis of reported cases of cutaneous leishmaniasis (CL) was performed using the data registered in the southern Ecuadorian Amazon region during 27 years from 1986 to 2012. The cases/subjects with both the suspected CL lesions and the amastigote-positive results were recruited for the analysis. The yearly occurrence of cases showed a markedly higher number during the six years, 1988 and 1993. After 1994 when the insecticide spraying campaign using helicopter in 1993-1994, the number dropped remarkably. Then, the yearly occurrence gradually fluctuated from 101 cases in 1996 to 11 in 2009, maintaining a low number of cases after the campaign. The monthly occurrence of cases showed a markedly high number during March and August, suggesting a correlation to the rainy season (months) in the areas. A statistical significance was found between the monthly average number of the CL case and the average precipitation (p=0.01474). It was suggested that the time of transmission of CL would depend on the rainy seasons at each endemic area of Ecuador, which has a diverse climatic feature depending on the geographic regions. Such information at given leishmaniasis-endemic areas of Ecuador would be important for the future planning of the disease control. Molecular analysis and characterization of clinical samples revealed the presence of Leishmania (Viannia) braziliensis.
  • Chukwunonso O Nzelu, Abraham G Cáceres, Martín J Arrunátegui-Jiménez, Máximo F Lañas-Rosas, Henrry H Yañez-Trujillano, Deysi V Luna-Caipo, Carlos E Holguín-Mauricci, Ken Katakura, Yoshihisa Hashiguchi, Hirotomo Kato
    Acta tropica 145 45 - 51 0001-706X 2015/05 [Refereed][Not invited]
     
    Phlebotomine sand flies are the only proven vectors of leishmaniases, a group of human and animal diseases. Accurate knowledge of sand fly species identification is essential in understanding the epidemiology of leishmaniasis and vector control in endemic areas. Classical identification of sand fly species based on morphological characteristics often remains difficult and requires taxonomic expertise. Here, we generated DNA barcodes of the cytochrome c oxidase subunit 1 (COI) gene using 159 adult specimens morphologically identified to be 19 species of sand flies, belonging to 6 subgenera/species groups circulating in Peru, including the vector species. Neighbor-joining (NJ) analysis based on Kimura 2-Parameter genetic distances formed non-overlapping clusters for all species. The levels of intraspecific genetic divergence ranged from 0 to 5.96%, whereas interspecific genetic divergence among different species ranged from 8.39 to 19.08%. The generated COI barcodes could discriminate between all the sand fly taxa. Besides its success in separating known species, we found that DNA barcoding is useful in revealing population differentiation and cryptic diversity, and thus promises to be a valuable tool for epidemiological studies of leishmaniasis.
  • Hirotomo Kato, Eduardo A Gomez, Megumi Fujita, Yuka Ishimaru, Hiroshi Uezato, Tatsuyuki Mimori, Hiroyuki Iwata, Yoshihisa Hashiguchi
    Biochimie 112 49 - 56 0300-9084 2015/05 [Refereed][Not invited]
     
    Sequence analysis of the Lutzomyia (Lu.) ayacuchensis salivary gland cDNA library identified a short peptide containing an RGD (Arg-Gly-Asp) sequence flanked by two cysteine residues in the C-terminal end as the most abundant transcript. In the present study, a recombinant protein of the RGD-containing peptide, designated ayadualin, was expressed in Escherichia coli and its activity was characterized. Ayadualin inhibited both collagen and ADP-induced platelet aggregations by interfering with the binding of integrin αIIbβ3 to fibrinogen. The RGD sequence and cysteine residues located on both sides of the RGD sequence were essential for the inhibitory action. Moreover, ayadualin efficiently inhibited the intrinsic blood coagulation pathway irrespective of the RGD sequence. Measuring the enzymatic activity of coagulation factors using chromogenic substrates revealed that ayadualin efficiently inhibited factor XIIa (FXIIa) activity in a dose-dependent manner. In addition, pre-incubation of ayadualin with FXII inhibited FXIIa activity, while activated FXIIa was not affected by ayadualin, indicating that ayadualin inhibits the activation of FXII, but not enzymatic activity of FXIIa. These results indicated that ayadualin plays an important role in the blood feeding of Lu. ayacuchensis by inhibiting host hemostasis via dual mechanisms.
  • Masashi Terao, Shirin Akter, Md Golam Yasin, Ryo Nakao, Hirotomo Kato, Mohammad Zahangir Alam, Ken Katakura
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 31 53 - 60 1567-1348 2015/04 [Refereed][Not invited]
     
    Babesia gibsoni is a tick-borne hemoprotozoan parasite of dogs that often causes fever and hemolytic illness. Detection of B. gibsoni has been predominantly reported in Asian countries, including Japan, Korea, Taiwan, Malaysia, Bangladesh and India. The present study shows the first molecular characterization of B. gibsoni detected from dogs in Bangladesh. Blood samples were collected on FTA® Elute cards from 50 stray dogs in Mymensingh District in Bangladesh. DNA eluted from the cards was subjected to nested PCR for the 18S rRNA gene of Babesia species. Approximately 800bp PCR products were detected in 15 of 50 dogs (30%). Based on restriction fragment length polymorphism (RFLP) and direct sequencing of the PCR products, all parasite isolates were identified as B. gibsoni. Furthermore, the BgTRAP (B. gibsoni thrombospondin-related adhesive protein) gene fragments were detected in 13 of 15 18S rRNA gene PCR positive blood samples. Phylogenetic analysis of the BgTRAP gene revealed that B. gibsoni parasites in Bangladesh formed a cluster, which was genetically different from other Asian B. gibsoni isolates. In addition, tandem repeat analysis of the BgTRAP gene clearly showed considerable genetic variation among Bangladeshi isolates. These results suggested that B. gibsoni parasites in a different genetic clade are endemic in dogs in Bangladesh. Further studies are required to elucidate the origin, distribution, vector and pathogenesis of B. gibsoni parasites circulating in dogs in Bangladesh.
  • Hirotomo Kato, Abraham G Cáceres, Eduardo A Gomez, Tatsuyuki Mimori, Hiroshi Uezato, Yoshihisa Hashiguchi
    Acta tropica 141 (Pt A) 79 - 87 0001-706X 2015/01 [Refereed][Not invited]
     
    Haplotype and gene network analyses were performed on mitochondrial cytochrome oxidase I and cytochrome b gene sequences of Lutzomyia (Lu.) ayacuchensis populations from Andean areas of Ecuador and southern Peru where the sand fly species transmit Leishmania (Leishmania) mexicana and Leishmania (Viannia) peruviana, respectively, and populations from the northern Peruvian Andes, for which transmission of Leishmania by Lu. ayacuchensis has not been reported. The haplotype analyses showed higher intrapopulation genetic divergence in northern Peruvian Andes populations and less divergence in the southern Peru and Ecuador populations, suggesting that a population bottleneck occurred in the latter populations, but not in former ones. Importantly, both haplotype and phylogenetic analyses showed that populations from Ecuador consisted of clearly distinct clusters from southern Peru, and the two populations were separated from those of northern Peru.
  • Kazue Hashiguchi, Lenin Velez N, Hirotomo Kato, Hipatia Criollo F, Daniel Romero A, Eduardo Gomez L, Luiggi Martini R, Flavio Zambrano C, Manuel Calvopina H, Abraham Caceres G, Yoshihisa Hashiguchi
    Tropical medicine and health 42 (4) 163 - 70 1349-4147 2014/12 [Refereed][Not invited]
     
    To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named "mini-Shannon trap" and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps.
  • Eduardo A Gomez, Hirotomo Kato, Yoshihisa Hashiguchi
    Acta tropica 140 41 - 9 0001-706X 2014/12 [Refereed][Not invited]
     
    A countrywide surveillance of sand flies was performed to obtain information on their geographical distribution and natural infection by Leishmania protozoa in Ecuador. A total of 18,119 sand flies were collected by human landing collections during 32 years from 1982 to 2014, and 29 species were recognized. The most prevalent 10 species were Lutzomyia gomezi, Lu. robusta, Lu. hartmanni, Lu. shannoni, Lu. trapidoi, Lu. panamensis, Lu. maranonensis, Lu. ayacuchensis, Lu. tortura and Lu. yuilli yuilli, and their topographical and vertical distributions were identified. Among all the sand flies, only 197 (1.09%) flies of four Lutzomyia species, Lu. gomezi, Lu. trapidoi, Lu. tortura and Lu. ayacuchensis, were positive for Leishmania. Endotrypanum, a flagellate parasite not pathogenic to humans, were detected in five Lutzomyia species, Lu. robusta, Lu. hartmanni, Lu. trapidoi, Lu. panamensis and Lu. yuilli yuilli, suggesting wide vector-ranges of Endotrypanum species. These data on the genus Lutzomyia and their natural infections with Leishmania and Endotrypanum will be useful for transmission studies and surveillance of leishmaniasis.
  • Eduardo A Gomez, Hirotomo Kato, Tatsuyuki Mimori, Yoshihisa Hashiguchi
    Acta tropica 137 118 - 22 0001-706X 2014/09 [Refereed][Not invited]
     
    Distribution of the vector species is a major risk factor for the endemicity of leishmaniasis. In the present study, the vertical distribution of Lutzomyia (Lu.) ayacuchensis, the vector of Leishmania (Leishmania) mexicana in the Ecuadorian Andes, was surveyed at different altitudes (300-2500m above sea level) of the Andean slope. The vector species Lu. ayacuchensis was identified at an altitude of 650m and a higher areas, and higher distribution ratio of the species was observed at higher altitudes. In addition, high ratios of L. (L.) mexicana infection were detected in higher areas, but none in lower populations of sand flies. Since an association between sand fly populations and vector competence is suggested in Lu. ayacuchensis, haplotype analysis was performed on the species from different altitudes of the study areas; however, no apparent difference was observed among populations. These results suggested that Lu. ayacuchensis in Andean slope areas of Ecuador has the potential to transmit L. (L.) mexicana and spread leishmaniasis in these areas.
  • Manuel Calvopina Hinojosa, Daniel Romero Alvarez, Hirotomo Kato, Yoshihisa Hashiguchi
    ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA 32 (7) 465 - 466 0213-005X 2014/08 [Refereed][Not invited]
  • Saw Bawm, Kohei Shimizu, Jun-Ichi Hirota, Yusuke Tosa, Lat Lat Htun, Ni Ni Maw, Myint Thein, Hirotomo Kato, Tatsuya Sakurai, Ken Katakura
    Parasitology international 63 (4) 640 - 5 1383-5769 2014/08 [Refereed][Not invited]
     
    Theileria orientalis is a causative agent of benign theileriosis in cattle and distributed in mainly Asian countries. In the present study, we examined the prevalence of T. orientalis infection by PCR based on the major piroplasm surface protein gene (MPSP) sequences in cattle in Myanmar, followed by phylogenetic analysis of the MPSP genes. The MPSP gene was amplified in 258 of 713 (36.2%) cattle blood DNA samples collected from five cities in different geographical regions of Myanmar. Phylogenetic analysis of MPSP sequences from 54 T. orientalis-positive DNA samples revealed the presence of six allelic genotypes, including Types 1, 3, 4, 5, 7, and N-3. Types 5 and 7 were the predominant types detected. Sequences of the MPSP genes detected in Myanmar were closely related to those from Thailand, Vietnam or Mongolia. These findings suggest that movement of animals carrying T. orientalis parasites between Southeast Asian countries could be a reason for the similar genotype distribution of the parasites in Myanmar.
  • K. Daly, H. De Lima, H. Kato, E. M. Sordillo, J. Convit, O. Reyes-Jaimes, O. Zerpa, A. E. Paniz-Mondolfi
    CLINICAL AND EXPERIMENTAL DERMATOLOGY 39 (6) 708 - 712 0307-6938 2014/08 [Refereed][Not invited]
     
    American cutaneous leishmaniasis is an endemic anthropozoonosis that exhibits a broad spectrum of clinical presentations. Intermediate/ borderline disseminated cutaneous leishmaniasis is a distinct clinical condition that comprises cutaneous disease of a chronic nature, usually occurring as multiple lesions with or without mucosal involvement. The disease is usually caused by parasites of the subgenus Viannia, frequently occurs in context of an underlying disease, and is often resistant to standard antileishmanial therapy. We report a case that was refractory to standard therapy and other second-line drugs, but resolved after treatment with fluconazole, and review the use of fluconazole as a second-line drug in children.
  • Mohammad Zahangir Alam, Abdul Manan Bhutto, Farooq Rahman Soomro, Javed Hussain Baloch, Ryo Nakao, Hirotomo Kato, Gabriele Schönian, Hiroshi Uezato, Yoshihisa Hashiguchi, Ken Katakura
    Parasites & vectors 7 332 - 332 1756-3305 2014/07 [Refereed][Not invited]
     
    BACKGROUND: Cutaneous leishmaniasis (CL) is a major and fast increasing public health problem, both among the local Pakistani populations and the Afghan refugees in camps. Leishmania (Leishmania) major is one of the etiological agents responsible for CL in Pakistan. Genetic variability and population structure have been investigated for 66 DNA samples of L. (L.) major isolated from skin biopsy of CL patients. METHODS: Multilocus microsatellite typing (MLMT), employing 10 independent genetic markers specific to L. (L.) major, was used to investigate the genetic polymorphisms and population structures of Pakistani L. (L.) major DNA isolated from CL human cases. Their microsatellite profiles were compared to those of 130 previously typed strains of L. (L.) major from various geographical localities. RESULTS: All the markers were polymorphic and fifty-one MLMT profiles were recognized among the 66 L. (L.) major DNA samples. The data displayed significant microsatellite polymorphisms with rare allelic heterozygosities. A Bayesian model-based approach and phylogenetic analysis inferred two L. (L.) major populations in Pakistan. Thirty-four samples belonged to one population and the remaining 32 L. (L.) major samples grouped together into another population. The two Pakistani L. (L.) major populations formed separate clusters, which differ genetically from the populations of L. (L.) major from Central Asia, Iran, Middle East and Africa. CONCLUSIONS: The considerable genetic variability of L. (L.) major might be related to the existence of different species of sand fly and/or rodent reservoir host in Sindh province, Pakistan. A comprehensive study of the epidemiology of CL including the situation or spreading of reservoirs and sand fly vectors in these foci is, therefore, warranted.
  • Chukwunonso O Nzelu, Eduardo A Gomez, Abraham G Cáceres, Tatsuya Sakurai, Luiggi Martini-Robles, Hiroshi Uezato, Tatsuyuki Mimori, Ken Katakura, Yoshihisa Hashiguchi, Hirotomo Kato
    Acta tropica 132 1 - 6 0001-706X 2014/04 [Refereed][Not invited]
     
    Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1h from a crude sand fly template without DNA purification. Amplicon detection could be accomplished by the newly developed colorimetric malachite green (MG)--mediated naked eye visualization. Pre-addition of MG to the LAMP reaction solution did not inhibit amplification efficiency. The field applicability of the colorimetric MG-based LAMP assay was demonstrated with 397 field-caught samples from the endemic areas of Ecuador and eight positive sand flies were detected. The robustness, superior sensitivity, and ability to produce better visual discriminatory reaction products than existing LAMP fluorescence and turbidity assays indicated the field potential usefulness of this new method for surveillance and epidemiological studies of leishmaniasis in developing countries.
  • Fabricio M Locatelli, S Pamela Cajal, Paola A Barroso, Juan J Lauthier, María C Mora, Marisa Juarez, Hirotomo Kato, Julio R Nasser, Yoshihisa Hashiguchi, Masataka Korenaga, Jorge D Marco
    Acta tropica 131 16 - 21 0001-706X 2014/03 [Refereed][Not invited]
     
    American tegumentary leishmaniasis (ATL) is a group of zoonotic diseases caused by kinetoplastid flagellates of the genus Leishmania. A total of 66 patients diagnosed as positive ATL cases from northwest Argentina were included in this study. Leishmania stocks were isolated in vitro and analyzed over promastigote cultures sown on FTA through nested PCR and sequence of cytochrome b (cyt b). The molecular analysis resulted in the incrimination of L. (Viannia) braziliensis as the predominant species in the studied area, identifying two genotypes of L. (V.) braziliensis, 24 cases of Ab-1 cyt b and 41 cases of Ab-2 cyt b. One L. (V.) guyanensis strain was obtained from a traveler from the Brazilian Amazon. The prevalence of different genotypes was in agreement with previous studies, suggesting the necessity for new systems to study the genetic diversity in more detail. Most of the cases typified in this study were registered in the area of Zenta Valley (Orán, Hipólito Yrigoyen, and Pichanal cities), pointing a link between genotype and geographical origin of the sample. Sex and age distribution of the patients indicate that the transmission was predominantly associated with rural areas or rural activities, although the results might not exclude the possibility of peri-urban transmission. This work represents, so far, the largest isolation and molecular characterization of ATL cases in Argentina.
  • Mohammad Zahangir Alam, Ryo Nakao, Tatsuya Sakurai, Hirotomo Kato, Jing-Qi Qu, Jun-Jie Chai, Kwang Poo Chang, Gabriele Schönian, Ken Katakura
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 22 112 - 9 1567-1348 2014/03 [Refereed][Not invited]
     
    The Leishmania strains from different epidemic areas in China were assessed for their genetic relationship. Twenty-nine strains of Leishmania infantum isolated from 1950 to 2001 were subjected to multilocus microsatellite typing (MLMT) using 14 highly polymorphic microsatellite markers. Twenty-two MLMT profiles were recognized among the 29 L. infantum strains, which differed from one another in 13 loci. Bayesian model-based and distance-based analysis of the data inferred two main populations in China. Sixteen strains belonged to one population, which also comprised previously characterized strains of L. infantum non-MON1 and Leishmania donovani. The parasites within this population are assignable to a distinct cluster that is clearly separable from the populations of L. donovani elsewhere, i.e. India, Sri Lanka and East Africa, and L. infantum non-MON1 from Europe. The remaining 13 Chinese strains grouped together with strains of L. infantum MON1 into another population, but formed a separate cluster which genetically differs from the populations of L. infantum MON1 from Europe, the Middle East, Central Asia and North Africa. The existence of distinct groups of L. infantum MON1 and non-MON1/L. donovani suggests that the extant parasites in China may have been restricted there, but not recently introduced from elsewhere.
  • Chukwunonso O Nzelu, Hirotomo Kato, Naiki Puplampu, Kwame Desewu, Shirley Odoom, Michael D Wilson, Tatsuya Sakurai, Ken Katakura, Daniel A Boakye
    PLoS neglected tropical diseases 8 (2) e2630  1935-2735 2014/02 [Refereed][Not invited]
     
    BACKGROUND: Leishmania major and an uncharacterized species have been reported from human patients in a cutaneous leishmaniasis (CL) outbreak area in Ghana. Reports from the area indicate the presence of anthropophilic Sergentomyia species that were found with Leishmania DNA. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we analyzed the Leishmania DNA positive sand fly pools by PCR-RFLP and ITS1 gene sequencing. The trypanosome was determined using the SSU rRNA gene sequence. We observed DNA of L. major, L. tropica and Trypanosoma species to be associated with the sand fly infections. This study provides the first detection of L. tropica DNA and Trypanosoma species as well as the confirmation of L. major DNA within Sergentomyia sand flies in Ghana and suggests that S. ingrami and S. hamoni are possible vectors of CL in the study area. CONCLUSIONS/SIGNIFICANCE: The detection of L. tropica DNA in this CL focus is a novel finding in Ghana as well as West Africa. In addition, the unexpected infection of Trypanosoma DNA within S. africana africana indicates that more attention is necessary when identifying parasitic organisms by PCR within sand fly vectors in Ghana and other areas where leishmaniasis is endemic.
  • Chukwunonso O. Nzelu, Hirotomo Kato, Naiki Puplampu, Kwame Desewu, Shirley Odoom, Michael D. Wilson, Tatsuya Sakurai, Ken Katakura, Daniel A. Boakye
    PLOS NEGLECTED TROPICAL DISEASES 8 (2) 1935-2735 2014/02 [Refereed][Not invited]
     
    BackgroundLeishmania major and an uncharacterized species have been reported from human patients in a cutaneous leishmaniasis (CL) outbreak area in Ghana. Reports from the area indicate the presence of anthropophilic Sergentomyia species that were found with Leishmania DNA. Methodology/Principal Findings In this study, we analyzed the Leishmania DNA positive sand fly pools by PCR-RFLP and ITS1 gene sequencing. The trypanosome was determined using the SSU rRNA gene sequence. We observed DNA of L. major, L. tropica and Trypanosoma species to be associated with the sand fly infections. This study provides the first detection of L. tropica DNA and Trypanosoma species as well as the confirmation of L. major DNA within Sergentomyia sand flies in Ghana and suggests that S. ingrami and S. hamoni are possible vectors of CL in the study area. Conclusions/Significance The detection of L. tropica DNA in this CL focus is a novel finding in Ghana as well as West Africa. In addition, the unexpected infection of Trypanosoma DNA within S. africana africana indicates that more attention is necessary when identifying parasitic organisms by PCR within sand fly vectors in Ghana and other areas where leishmaniasis is endemic. Author Summary Cutaneous leishmaniasis (CL) is one of the world's most neglected diseases transmitted by female sand flies and affecting mostly developing countries with about 1.2 million cases every year. In most African countries, the disease is typically caused by one of two species of Leishmania parasite: L. major or L. tropica. Clinical symptoms of both infections are similar, producing ulcerative and nodular lesions. Notwithstanding their similarity, lesions caused by L. major self-heal and bestow immunity to re-infection and therapy, if applied, is often by antimonials administered intra-lesionally, whereas the treatment of CL caused by L. tropica is difficult. Differentiating between these agents in any CL focus is important. Following the outbreak of CL in Ghana, we focused on the sand fly species present in the area in order to detect Leishmania DNA in potential vectors. Our study provides evidence on the occurrence of L. tropica and L. major DNA, and the detection of Trypanosoma DNA in Sergentomyia sand flies in Ghana. These findings have considerable implications in determining the epidemiology and dynamics of the disease. Significantly, our study supports the possibility of Sergentomyia sand flies as the vectors of CL in Ghana other than Phlebotomus, which contains all currently known vectors for Leishmania in the Old World.
  • Hirotomo Kato, Manuel Calvopiña, Hipatia Criollo, Yoshihisa Hashiguchi
    Acta tropica 128 (3) 710 - 3 0001-706X 2013/12 [Refereed][Not invited]
     
    Epidemiological surveillance of leishmaniasis was conducted in a northern Amazonian region of Ecuador, in which cutaneous leishmaniasis cases were recently reported. Sand flies were captured in the military training camp, and the natural infection of sand flies by Leishmania species was examined. Out of 334 female sand flies dissected, the natural infection by flagellates was microscopically detected in 3.9% of Lutzomyia yuilli yuilli and 3.7% of Lutzomyia tortura, and the parasite species were identified as Endotrypanum and Leishmania (Viannia) naiffi, respectively. After the sand fly surveillance, specimens from cutaneous leishmaniasis (CL) patients considered to have acquired the infection in the training camp area were obtained, and the infected parasite species were identified as L. (V.) naiffi. The present study reported first cases of CL caused by L. (V.) naiffi infection in Ecuador. In addition, a high ratio of infection of Lu. tortura by L. (V.) naiffi in the same area strongly suggested that Lu. tortura is responsible for the transmission of L. (V.) naiffi in this area.
  • Manuel Calvopiña, Hirotomo Kato, Yoshihisa Hashiguchi
    Tropical medicine and health 41 (3) 93 - 4 1348-8945 2013/09 [Refereed][Not invited]
  • Kento Yamamoto, Abraham G Cáceres, Eduardo A Gomez, Tatsuyuki Mimori, Hiroyuki Iwata, Masataka Korenaga, Tatsuya Sakurai, Ken Katakura, Yoshihisa Hashiguchi, Hirotomo Kato
    Acta tropica 126 (2) 156 - 63 0001-706X 2013/05 [Refereed][Not invited]
     
    The genetic divergence caused by genetic drift and/or selection is suggested to affect the vectorial capacity and insecticide susceptibility of sand flies, as well as other arthropods. In the present study, cytochrome b (cyt b) gene sequences were determined in 13 species circulating in Peru to establish a basis for analysis of the genetic structure, and the intraspecific genetic diversity was assessed in the Lutzomyia (Lu.) peruensis, a main vector species of Leishmania (Viannia) peruviana in Peruvian Andes. Analysis of intraspecific genetic diversity in the cyt b gene sequences from 36 Lu. peruensis identified 3 highly polymorphic sites in the middle region of the gene. Haplotype and gene network analyses were performed on the cyt b gene sequences of 130 Lu. peruensis in 9 Andean areas from 3 Departments (Ancash, Lima and La Libertad). The results showed that the populations of La Libertad were highly polymorphic and that their haplotypes were distinct from those of Ancash and Lima, where dominant haplotypes were observed, suggesting that a population bottleneck may have occurred in Ancash and Lima, but not in La Libertad. The present study indicated that the middle region of the cyt b gene is useful for the analysis of genetic structure in sand fly populations.
  • Saovanee Leelayoova, Suradej Siripattanapipong, Atitaya Hitakarun, Hirotomo Kato, Peerapan Tan-ariya, Padet Siriyasatien, Seksit Osatakul, Mathirut Mungthin
    BMC microbiology 13 60 - 60 1471-2180 2013/03 [Refereed][Not invited]
     
    BACKGROUND: Visceral leishmaniasis (VL) caused by Leishmania siamensis is an emerging disease continuously reported in six southern provinces of Thailand. To date, the phylogenetic relationships among Leishmania isolates from Thai patients and other Leishmania species are still unclear and the taxonomic diversity needs to be established. In this study, the phylogenetic inference trees were constructed based on four genetic loci (i.e., SSU-rRNA, ITS1, hsp70, and cyt b), using DNA sequences obtained from autochthonous VL patients from southern Thailand and reference sequences of reported Leishmania isolates from other studies deposited in GenBank. RESULTS: Phylogenetic analyses of hsp70 and cyt b loci supported a clade comprised of L. siamensis isolates, which is independent to the other members in the genus Leishmania. In combination with genetic distance analysis, sequence polymorphisms were observed among L. siamensis isolates and two different lineages could be differentiated, lineages PG and TR. Phylogenetic analysis of the cyt b gene further showed that L. siamensis lineage TR is closely related to L. enrietti, a parasite of guinea pigs. CONCLUSION: The finding of this study sheds further light on the relationships of L. siamensis, both in intra- and inter-species aspects. This information would be useful for further in-depth studies on the biological properties of this important parasite.
  • Angel G Guevara, Richard D Atherton, Michael A Wauters, Yosselin Vicuña, Marcos Nelson, Jose Prado, Hirotomo Kato, Manuel H Calvopiña, Yoshihisa Hashiguchi
    Tropical medicine and health 41 (1) 21 - 5 1348-8945 2013/03 [Refereed][Not invited]
     
    To determine the extent of Trypanosoma cruzi infection and/or transmission in the southern Amazon region of Ecuador, three indigenous communities in the provinces of Pastaza and Morona Santiago were serosurveyed. Chagatest(TM), Immunocomb(®)II and immunofluorescent (IF) assays were used. Among the 385 inhabitants examined, nine (2.34%) were seropositive for T. cruzi infection. Of the nine positive sera, four (44.4%) fall in the 10-19, one each in the 20-29, 30-39 and 40-49, and two in the 50-59 age groups. These results suggested the possible existence of an autochthonous active T. cruzi transmission in the region and provide the first serological evidence for T. cruzi infection in the southern province of Morona Santiago bordering Peru. Further studies are needed in these Amazonian provinces to ascertain the spread of T. cruzi infection in the area.
  • Mohammad Zahangir Alam, Golam Yasin, Hirotomo Kato, Tatsuya Sakurai, Ken Katakura
    The Journal of veterinary medical science 75 (1) 75 - 8 0916-7250 2013/01 [Refereed][Not invited]
     
    Although Phlebotomus argentipes as the only known vector of visceral leishmaniasis (VL) is zoophilic in nature, VL is considered to be anthroponotic in the Indian subcontinent. Peripheral blood samples from 85 stray dogs were examined for any molecular evidence of Leishmania infection in VL endemic areas of Bangladesh. Parasite DNA was detected in a blood sample from 1 of 85 (1.2%) stray dogs using ITS1-PCR, and PCR sequencing of the rRNA-ITS and cytochrome b gene confirmed that the parasitic DNA was Leishmania donovani. The results support the assumption that dogs are a probable animal reservoir for the Leishmania parasite in Bangladesh. It will be important to investigate the possible epidemiological role of dogs in domestic foci of VL endemic areas in Bangladesh.
  • Hirotomo Kato, Ryan C Jochim, Eduardo A Gomez, Hiroshi Uezato, Tatsuyuki Mimori, Masataka Korenaga, Tatsuya Sakurai, Ken Katakura, Jesus G Valenzuela, Yoshihisa Hashiguchi
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 13 56 - 66 1567-1348 2013/01 [Refereed][Not invited]
     
    The saliva of blood sucking insects contains potent pharmacologically active components that assist them in counteracting the host hemostatic and inflammatory systems during blood feeding. In addition, sand fly salivary proteins affect host immunity and have the potential to be a vaccine against Leishmania infection. In the present study, the salivary gland transcripts of Lutzomyia ayacuchensis, a vector of cutaneous leishmaniasis in Ecuadorian and Peruvian Andes, were analyzed by sequencing randomly selected clones of the salivary gland cDNA library of this sand fly. This resulted in the identification of the most abundant transcripts coding for secreted proteins. These proteins were homologous to the salivary molecules present in other sand flies including the RGD-containing peptide, PpSP15/SL1 family protein, yellow-related protein, putative apyrase, antigen 5-related protein, D7 family protein, and 27 kDa salivary protein. Of note, homologues of maxadilan, an active vasodilator abundantly present in saliva of Lutzomyia longipalpis, were not identified. This analysis is the first description of salivary proteins from a sand fly of the subgenus Helcocyrtomyia and from vector of cutaneous leishmaniasis in the New World. The present analysis will provide further insights into the evolution of salivary components in blood sucking arthropods.
  • Yuka Ishimaru, Eduardo A Gomez, Feifei Zhang, Luiggi Martini-Robles, Hiroyuki Iwata, Tatsuya Sakurai, Ken Katakura, Yoshihisa Hashiguchi, Hirotomo Kato
    The Journal of experimental biology 215 (Pt 20) 3597 - 602 0022-0949 2012/10 [Refereed][Not invited]
     
    Sequence analysis of a Triatoma dimidiata salivary gland cDNA library resulted in the identification of two transcripts (Td60 and Td101) homologous to triabin, an inhibitor of thrombin in Triatoma pallidipennis saliva. In the present study, a recombinant protein of Td60, designated dimiconin, was expressed in Escherichia coli and its activity was characterized. The resulting protein inhibited the intrinsic but not extrinsic blood coagulation pathway, suggesting that dimiconin is not a thrombin inhibitor. Measurement of the enzymatic activity of coagulation factors using chromogenic substrates revealed that dimiconin efficiently inhibited factor XIIa (FXIIa) activity in a dose-dependent manner. In addition, pre-incubation of dimiconin with FXII effectively inhibited FXIIa activity whereas dimiconin did not affect already activated FXIIa, indicating that dimiconin inhibits the activation of FXII but not the enzymatic activity of FXIIa. These results show that dimiconin is an inhibitor of the contact phase initiated by FXII activation in the blood coagulation cascade, which differs from the bioactivity of triabin.
  • Saruda Tiwananthagorn, Kazuya Iwabuchi, Manabu Ato, Tatsuya Sakurai, Hirotomo Kato, Ken Katakura
    PLOS NEGLECTED TROPICAL DISEASES 6 (8) 1935-2735 2012/08 [Refereed][Not invited]
     
    Visceral leishmaniasis (VL) is a chronic and fatal disease in humans and dogs caused by the intracellular protozoan parasites, Leishmania donovani and L. infantum (L. chagasi). Relapse of disease is frequent in immunocompromised patients, in which the number of VL cases has been increasing recently. The present study is aimed to improve the understanding of mechanisms of L. donovani persistence in immunocompromised conditions using alymphoplastic aly/aly mice. Hepatic parasite burden, granuloma formation and induction of regulatory T cells were determined for up to 7 months after the intravenous inoculation with L. donovani promastigotes. While control aly/+ mice showed a peak of hepatic parasite growth at 4 weeks post infection (WPI) and resolved the infection by 8 WPI, aly/aly mice showed a similar peak in hepatic parasite burden but maintained persistent in the chronic phase of infection, which was associated with delayed and impaired granuloma maturation. Although hepatic CD4(+)Foxp3(+) but not CD8(+)Foxp3(+) T cells were first detected at 4 WPI in both strains of mice, the number of CD4(+)Foxp3(+)T cells was significantly increased in aly/aly mice from 8 WPI. Immunohistochemical analysis demonstrated the presence of Foxp3(+) T cells in L. donovani-induced hepatic granulomas and perivascular neo-lymphoid aggregates. Quantitative real-time PCR analysis of mature granulomas collected by laser microdissection revealed the correlation of Foxp3 and IL-10 mRNA level. Furthermore, treatment of infected aly/aly mice with anti-CD25 or anti-FR4 mAb resulted in significant reductions in both hepatic Foxp3(+) cells and parasite burden. Thus, we provide the first evidence that CD4(+)Foxp3(+) Tregs mediate L. donovani persistence in the liver during VL in immunodeficient murine model, a result that will help to establish new strategies of immunotherapy against this intracellular protozoan pathogen.
  • Megumi Fujita, Hirotomo Kato, Abraham G Cáceres, Eduardo A Gomez, Lenin Velez, Tatsuyuki Mimori, Feifei Zhang, Hiroyuki Iwata, Masataka Korenaga, Tatsuya Sakurai, Ken Katakura, Yoshihisa Hashiguchi
    Acta tropica 121 (2) 93 - 8 0001-706X 2012/02 [Refereed][Not invited]
     
    Genotyping of sand fly species circulating in Peru was established on the basis of PCR-restriction fragment length polymorphisms (RFLPs) of the 18S ribosomal RNA (rRNA) gene. The sequences of 18S rRNA gene fragments from 12 Lutzomyia and 1 Warileya species were determined and their RFLP-patterns were analyzed. Consequently, RFLP analysis with the restriction enzyme AfaI and then HapII or KpnI, followed by XspI successfully differentiated them. Intraspecific genetic diversity affecting RFLP-patterns was not detected in the specimens collected from 24 areas of 8 departments. The genotyping was applied to the surveillance of sand flies collected from Andean areas where leishmaniasis is endemic, and its usability was verified. The present method promises to be a powerful tool for the classification and surveillance of sand flies circulating in Peru.
  • Mohammad Shafiul Alam, Hirotomo Kato, Mizuho Fukushige, Yukiko Wagatsuma, Makoto Itoh
    Journal of parasitology research 2012 467821 - 467821 2090-0023 2012 [Refereed][Not invited]
     
    Mymensingh is the most endemic district for kala-azar in Bangladesh. Phlebotomus argentipes remains the only known vector although a number of sand fly species are prevalent in this area. Genotyping of sand flies distributed in a VL endemic area was developed by a PCR and restriction-fragment-length polymorphism (RFLP) of 18S rRNA gene of sand fly species. Using the RFLP-PCR analysis with AfaI and HinfI restriction enzymes, P. argentipes, P. papatasi, and Sergentomyia species could be identified. Among 1,055 female sand flies successfully analyzed for the species identification individually, 64.4% flies was classified as Sergentomyia species, whereas 35.6% was identified as P. argentipes and no P. papatasi was found. Although infection of Leishmania within the sand flies was individually examined targeting leishmanial minicircle DNA, none of the 1,055 sand flies examined were positive for Leishmania infection. The RFLP-PCR could be useful tools for taxonomic identification and Leishmania infection monitoring in endemic areas of Bangladesh.
  • Saruda Tiwananthagorn, Kazuya Iwabuchi, Manabu Ato, Tatsuya Sakurai, Hirotomo Kato, Ken Katakura
    PLoS neglected tropical diseases 8 6 (8) e1798  1935-2727 2012 [Refereed][Not invited]
     
    Visceral leishmaniasis (VL) is a chronic and fatal disease in humans and dogs caused by the intracellular protozoan parasites, Leishmania donovani and L. infantum (L. chagasi). Relapse of disease is frequent in immunocompromised patients, in which the number of VL cases has been increasing recently. The present study is aimed to improve the understanding of mechanisms of L. donovani persistence in immunocompromised conditions using alymphoplastic aly/aly mice. Hepatic parasite burden, granuloma formation and induction of regulatory T cells were determined for up to 7 months after the intravenous inoculation with L. donovani promastigotes. While control aly/+ mice showed a peak of hepatic parasite growth at 4 weeks post infection (WPI) and resolved the infection by 8 WPI, aly/aly mice showed a similar peak in hepatic parasite burden but maintained persistent in the chronic phase of infection, which was associated with delayed and impaired granuloma maturation. Although hepatic CD4(+)Foxp3(+) but not CD8(+)Foxp3(+) T cells were first detected at 4 WPI in both strains of mice, the number of CD4(+)Foxp3(+) T cells was significantly increased in aly/aly mice from 8 WPI. Immunohistochemical analysis demonstrated the presence of Foxp3(+) T cells in L. donovani-induced hepatic granulomas and perivascular neo-lymphoid aggregates. Quantitative real-time PCR analysis of mature granulomas collected by laser microdissection revealed the correlation of Foxp3 and IL-10 mRNA level. Furthermore, treatment of infected aly/aly mice with anti-CD25 or anti-FR4 mAb resulted in significant reductions in both hepatic Foxp3(+) cells and parasite burden. Thus, we provide the first evidence that CD4(+)Foxp3(+) Tregs mediate L. donovani persistence in the liver during VL in immunodeficient murine model, a result that will help to establish new strategies of immunotherapy against this intracellular protozoan pathogen.
  • Hirotomo Kato, Junko Watanabe, Iraida Mendoza Nieto, Masataka Korenaga, Yoshihisa Hashiguchi
    Transactions of the Royal Society of Tropical Medicine and Hygiene 105 (10) 561 - 7 0035-9203 2011/10 [Refereed][Not invited]
     
    A molecular epidemiological study was performed using FTA card materials directly sampled from lesions of patients with cutaneous leishmaniasis (CL) in the state of Lara, Venezuela, where causative agents have been identified as Leishmania (Viannia) braziliensis and L. (Leishmania) venezuelensis in previous studies. Of the 17 patients diagnosed with CL, Leishmania spp. were successfully identified in 16 patients based on analysis of the cytochrome b gene and rRNA internal transcribed spacer sequences. Consistent with previous findings, seven of the patients were infected with L. (V.) braziliensis. However, parasites from the other nine patients were genetically identified as L. (L.) mexicana, which differed from results of previous enzymatic and antigenic analyses. These results strongly suggest that L. (L.) venezuelensis is a variant of L. (L.) mexicana and that the classification of L. (L.) venezuelensis should be reconsidered.
  • Hirotomo Kato, Eduardo A Gomez, Abraham G Cáceres, Franklin Vargas, Tatsuyuki Mimori, Kento Yamamoto, Hiroyuki Iwata, Masataka Korenaga, Lenin Velez, Yoshihisa Hashiguchi
    Vector borne and zoonotic diseases (Larchmont, N.Y.) 11 (5) 515 - 21 1530-3667 2011/05 [Refereed][Not invited]
     
    The natural infection of sand flies by Leishmania species was studied in the Andean areas of Peru where cutaneous leishmaniasis caused by Leishmania (Viannia) peruviana is endemic. Sand flies were captured by human bait and Center for Disease Control (CDC) light trap catches at Nambuque and Padregual, Department of La Libertad, Peru, and morphologically identified. Among 377 female sand flies dissected, the two dominant man-biting species were Lutzomyia (Helcocyrtomyia) peruensis (211 flies) and Lutzomyia (Helcocyrtomyia) caballeroi (151 flies). Another sand fly species captured by light trap was Warileya phlebotomanica (15 flies). The natural infection of sand flies by flagellates was detected in 1.4% of Lu. (H.) peruensis and 2.6% of Lu. (H.) caballeroi, and the parasite species were identified as Le. (V.) peruviana and Trypanosoma avium, respectively, by molecular biological methods. The results indicated that the vector species responsible for the transmission of leishmaniasis in the study areas is Lu. (H.) peruensis. In addition, the presence of Trypanosoma in man-biting sand fly species means that more careful consideration is necessary for vector research in areas of Andean Peru where leishmaniasis is endemic.
  • Ofelia Córdova, Franklin Vargas Vásquez, Yoshihisa Hashiguchi, Hirotomo Kato, Eduardo Gómez
    Revista Peruana de Medicina Experimental y Salud Publica 28 (3) 446 - 453 1726-4642 2011 [Refereed][Not invited]
     
    Objectives. To identify the species of Leishmania present in the skin lesions of patients and Lutzomyias living in endemic areas of La Libertad, Peru. Materials and methods. Molecular methods based on PCR and RFLP were used, which allowed to have efficient data with small amounts of samples (small specimens), due to their high sensitivity and ease of application in the field work. Results. The results of PCR of clinical samples of patients and insect vectors showed the presence of Leishmania (V.) peruviana as a major causative agent of andean leishmaniasis transmitted by Lutzomyia peruensis. The presence of Leishmania (V.) guyanensis in Lutzomyia ayacuchensis, was found as well. Conclusions. The presence of L. (V.) peruviana and L. (V.) guyanensis in the Andean areas under study was found. These findings remark the need of a wider research about the geographical distribution of L. (V.) guyanensis and clinical features related to the infection in endemic areas of cutaneous leishmaniasis.
  • Hirotomo Kato, Abraham G Cáceres, Tatsuyuki Mimori, Yuka Ishimaru, Amal S M Sayed, Megumi Fujita, Hiroyuki Iwata, Hiroshi Uezato, Lenin N Velez, Eduardo A L Gomez, Yoshihisa Hashiguchi
    Journal of clinical microbiology 48 (10) 3661 - 5 0095-1137 2010/10 [Refereed][Not invited]
     
    The FTA card (Whatman) was assessed for its utility as a molecular epidemiological tool in collecting samples from patients with leishmaniasis in Peru because the card has a variety of merits; it is less invasive for patients and easy to handle for both physicians and other medical personnel for sample collection or diagnosis, in addition to its simplicity and easy countrywide and/or intercountry transportation for analysis. Samples were collected from 132 patients suspected of having leishmaniasis, and Leishmania species were successfully identified in samples from 81 patients in 15 departments of Peru by cytochrome b and mannose phosphate isomerase gene analyses. Of these, 61.7% were identified as Leishmania (Viannia) peruviana, 22.2% as L. (V.) braziliensis, 12.3% as L. (V.) guyanensis, 2.5% as L. (V.) shawi, and 1.2% as L. (V.) lainsoni. The three predominant species, L. (V.) peruviana, L. (V.) braziliensis, and L. (V.) guyanensis, were mainly found in the Andean highlands, in the tropical rainforest, and in northern and central rainforest regions, respectively. This is the first time L. (V.) shawi has been identified outside Brazil. The present study showed that the FTA card will be a useful tool for the ecological study of different forms of leishmaniasis. Furthermore, collecting samples directly from patients' lesions by using the FTA card eliminates (i) the possibility of contamination of Leishmania isolates during short- and/or long-term passages of culture in vitro in each laboratory and (ii) pain and suffering of patients from taking samples by skin biopsy.
  • Hirotomo Kato, Ryan C Jochim, Eduardo A Gomez, Ryo Sakoda, Hiroyuki Iwata, Jesus G Valenzuela, Yoshihisa Hashiguchi
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 10 (2) 184 - 91 1567-1348 2010/03 [Refereed][Not invited]
     
    Triatoma (T.) dimidiata is a hematophagous Hemiptera and a main vector of Chagas disease. The saliva of this and other blood-sucking insects contains potent pharmacologically active components that assist them in counteracting the host hemostatic and inflammatory systems during blood feeding. To describe the repertoire of potential bioactive salivary molecules from this insect, a number of randomly selected transcripts from the salivary gland cDNA library of T. dimidiata were sequenced and analyzed. This analysis showed that 77.5% of the isolated transcripts coded for putative secreted proteins, and 89.9% of these coded for variants of the lipocalin family proteins. The most abundant transcript was a homologue of procalin, the major allergen of T. protracta saliva, and contributed more than 50% of the transcripts coding for putative secreted proteins, suggesting that it may play an important role in the blood-feeding process. Other salivary transcripts encoding lipocalin family proteins had homology to triabin (a thrombin inhibitor), triafestin (an inhibitor of kallikrein-kinin system), pallidipin (an inhibitor of collagen-induced platelet aggregation) and others with unknown function.
  • Hirotomo Kato, Eduardo A Gomez, Abraham G Cáceres, Hiroshi Uezato, Tatsuyuki Mimori, Yoshihisa Hashiguchi
    International journal of environmental research and public health 7 (3) 814 - 26 1661-7827 2010/03 [Refereed][Not invited]
     
    Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.
  • Hirotomo Kato, Hiroshi Uezato, Hiroshi Sato, Abdul M Bhutto, Farooq R Soomro, Javed H Baloch, Hiroyuki Iwata, Yoshihisa Hashiguchi
    Parasites & vectors 3 10 - 10 1756-3305 2010/02 [Refereed][Not invited]
     
    The natural infection of phlebotomine sand flies by Leishmania parasites was surveyed in a desert area of Pakistan where cutaneous leishmaniasis is endemic. Out of 220 female sand flies dissected, one sand fly, Phlebotomus kazeruni, was positive for flagellates in the hindgut. Analyses of cytochrome b (cyt b), glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and small subunit ribosomal RNA (SSU rRNA) gene sequences identified the parasite as a Trypanosoma species of probably a reptile or amphibian. This is the first report of phlebotomine sand flies naturally infected with a Trypanosoma species in Pakistan. The possible infection of sand flies with Trypanosoma species should be taken into consideration in epidemiological studies of vector species in areas where leishmaniasis is endemic.
  • Kei Kuwahara, Hirotomo Kato, Eduardo A Gomez, Hiroshi Uezato, Tatsuyuki Mimori, Yu-ichi Yamamoto, Manuel Calvopiña, Abraham G Cáceres, Hiroyuki Iwata, Yoshihisa Hashiguchi
    Acta tropica 112 (2) 131 - 6 0001-706X 2009/11 [Refereed][Not invited]
     
    In this study, each of 60 rRNA internal transcribed spacer (ITS) 1 and ITS2 sequences was determined from 44 individuals of 14 morphologically identified New World sand fly Lutzomyia species in Ecuador, and their interspecies and intraspecies genetic diversity was compared. Distinguishing between related species based on the ITS1 sequence was difficult because of variability, while the genetic diversity of ITS2 was distinct even among closely related species. Further, an assessment of intraspecies ITS sequence diversity in the subgenus Helcocyrtomyia revealed no correlation between sequence variation and geographic distribution. The results strongly suggested ITS2 to be a more suitable marker than ITS1 for the taxonomic analysis of Lutzomyia species including closely related species. Moreover, neither ITS sequence may be useful for the analysis of population structures in Lutzomyia species.
  • Ryoichi Hamasaki, Hirotomo Kato, Yoshimi Terayama, Hiroyuki Iwata, Jesus G Valenzuela
    Journal of insect physiology 55 (11) 1044 - 9 0022-1910 2009/11 [Refereed][Not invited]
     
    Two transcripts coding for proteins homologous to apyrases were identified by massive sequencing of a Phlebotomus (P.) duboscqi salivary gland cDNA library. The sequence analysis revealed that the amino acids important for enzymatic activity including nucleotidase activity and the binding of calcium and nucleotides were well conserved in these molecules. A recombinant P. duboscqi salivary apyrase was expressed in Escherichia coli and purified. The resulting protein efficiently hydrolyzed ADP and ATP, but not AMP, GDP, CDP or UDP, in a calcium-dependent manner. Further, the recombinant protein inhibited ADP- and collagen-induced platelet aggregation. The results indicated that this salivary protein plays an important role in the blood-feeding process in P. duboscqi. Its unique enzymatic activity makes the salivary apyrase an attractive candidate as a therapeutic agent for the treatment of thrombotic pathologies as well as a reagent for a wide variety of research purposes.
  • Natsuko Takatsuka, Atsuhiko Hasegawa, Ayako Takamori, Yukiko Shimizu, Hirotomo Kato, Takashi Ohashi, Teruo Amagasa, Takao Masuda, Mari Kannagi
    International immunology 21 (9) 1089 - 100 0953-8178 2009/09 [Refereed][Not invited]
     
    Human T-cell leukemia virus type I (HTLV-I) is associated with adult T-cell leukemia, HTLV-I-associated myelopathy/tropical spastic paraparesis and various autoimmune-like disorders. T-cell immune suppression is also associated with HTLV-I infection. Mechanisms of diverse immune dysregulation in HTLV-I infection are obscure. Here, we investigated a potential link between autoimmunity and immune suppression in HTLV-I infection. G14, an IL-2-dependent HTLV-I-negative CD4(+)CD8(+) T-cell line previously established from an HTLV-I-infected rat, constantly proliferated and produced IFN-gamma. IFN-gamma production by G14 cells was dependent on interactions between CD4 and MHC-II, suggesting that G14 cells recognized self-antigens presented by MHC-II on themselves. To examine immune response to G14 cells, we inoculated G14 cells into syngeneic naive rats. Interestingly, T-cells isolated from these rats vigorously proliferated when stimulated with G14-Tax cells that stably expressed HTLV-I Tax, but not with G14 cells. G14-Tax-mediated T-cell proliferation was abrogated by antibodies to CD80 and CD86 that were up-regulated in G14-Tax cells. T-cells propagated by repetitive G14-Tax cell stimulations in culture with IL-2 expressed CD4, CD25 and cytolytic T lymphocyte-associated antigen 4 (CTLA-4), produced abundant amounts of IL-10 and IFN-gamma in response to G14 cells and suppressed growth of G14 cells mainly through supernatant-mediated mechanisms. Similar IL-10- and IFN-gamma-producing CD4(+)CD25(+)CTLA-4(+) T-cells were predominantly induced in culture of splenocytes from HTLV-I-infected rats following stimulation with G14-Tax cells. These results implied that expression of Tax in the otherwise low immunogenic autoreactive T-cells induced IL-10- and IFN-gamma-producing T-cell responses with regulatory effects against the autoreactive cells. Our findings provide new insights into the complex immune conditions underlying HTLV-I-associated diseases.
  • Yutaka Asato, Minoru Oshiro, Chomar Kaung Myint, Yu-ichi Yamamoto, Hirotomo Kato, Jorge Diego Marco, Tatsuyuki Mimori, Eduardo A L Gomez, Yoshihisa Hashiguchi, Hiroshi Uezato
    Experimental parasitology 121 (4) 352 - 61 0014-4894 2009/04 [Refereed][Not invited]
     
    In a previous report (Luyo-Acero et al., 2004), we demonstrated that cytochrome b (Cyt b) gene analysis is an effective method for classifying several isolates of the genus Leishmania; hence, we have further applied this method to other Leishmania species in an effort to enhance the accuracy of the procedure and to construct a new phylogenic tree. In this study, a total of 30 Leishmania and Endotrypanum WHO reference strains, clinical isolates from our patients assigned to 28 strains (human and non-human pathogenic species) and two species of the genus Endotrypanum were analyzed. The Cyt b gene in each sample was amplified by PCR, and was then sequenced by several primers, as reported previously. The phylogenic tree was constructed based on the results obtained by the computer software MEGA v3.1 and PAUP* v4.0 Beta. The present phylogenic tree was almost identical to the traditional method of classification proposed by Lainson and Shaw (1987). However, it produces the following suggestions: (1) exclusion of L. (Leishmania) major from the L. (L.) tropica complex; (2) placement of L.tarentolae in the genus Sauroleishmania; (3) L. (L.) hertigi complex and L. (V.) equatorensis close to the genus Endotrypanum; (4) L. (L.) enrietti, defined as L. (L.) mexicana complex, placed in another position; and (5) L. (L.) turanica and L. (L.) arabica are located in an area far from human pathogenic Leishmania strains. Cyt b gene analysis is thus applicable to the analyzing phylogeny of the genus Leishmania and may be useful for separating non-human pathogenic species from human pathogenic species.
  • Reiko Nakagawa-Okamoto, Tomoko Arita-Nishida, Shoichi Toda, Hirotomo Kato, Hiroyuki Iwata, Miho Akiyama, Osamu Nishio, Hirokazu Kimura, Mamoru Noda, Naokazu Takeda, Tomoichiro Oka
    Japanese journal of infectious diseases 62 (1) 63 - 6 1344-6304 2009/01 [Refereed][Not invited]
     
    This report describes multiple viruses in stool specimens from oyster-associated gastroenteritis. Eleven outbreaks of oyster-associated gastroenteritis were examined for enteric viruses between January 2002 and March 2006 in Japan. Multiple norovirus genotypes were detected in all outbreaks; moreover, kobuvirus, sapovirus, and astrovirus were also detected in 6, 3, and 1 of the 11 outbreaks, respectively. Notably, multiple sapovirus genogroups were detected in the stool specimens from subjects in two oyster-associated gastroenteritis outbreaks.
  • Hirotomo Kato, Abraham G Cáceres, Eduardo A Gomez, Tatsuyuki Mimori, Hiroshi Uezato, Jorge D Marco, Paola A Barroso, Hiroyuki Iwata, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 79 (5) 719 - 21 0002-9637 2008/11 [Refereed][Not invited]
     
    Sand flies from the Andean areas of Ecuador and Peru were examined for Leishmania infections by using our recently established molecular mass screening method. Leishmanial minicircle DNA-positive sand flies were detected in 3 of 192 and 1 of 462 samples from Ecuador and Peru, respectively. Sand fly species were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the 18S ribosomal RNA (rRNA) gene, and the positive flies were Lutzomyia (Lu.) ayacuchensis and Lu. peruensis, respectively. Furthermore, cytochrome b and mannose-phosphate isomerase gene sequence analyses identified the parasites from Ecuador and Peru as Leishmania (Leishmania) mexicana and L. (Viannia) peruviana, respectively. Thus, the mass screening method was confirmed to be a powerful tool for sand fly research.
  • Hirotomo Kato, Eduardo A Gomez, Yu-ichi Yamamoto, Manuel Calvopiña, Angel G Guevara, Jorge D Marco, Paola A Barroso, Hiroyuki Iwata, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 79 (3) 438 - 40 0002-9637 2008/09 [Refereed][Not invited]
     
    Natural infection of sand flies with Leishmania parasites was surveyed in an Amazonian area in Ecuador where leishmaniasis is endemic. Seventy-one female sand flies were dissected and one was positive for Leishmania protozoa. The species of this sand fly was identified as Lutzomyia (Lu.) tortura on the basis of morphologic characteristics. Analysis of the cytochrome b gene sequence identified the parasite as L. (Viannia) naiffi. We report the distribution of L. (V.) naiffi in Ecuador and detection of a naturally infected sand fly in the Ecuadorian Amazon and natural infection of Lu. tortura with Leishmania parasites in the New World.
  • 寺山 好美, 加藤 大智, Gomez E.A., 上里 博, Calvopina M., 岩田 祐之, 橋口 義久
    The Journal of Veterinary Medical Science 70 (9) 907 - 913 0916-7250 2008/09 [Refereed][Not invited]
     
    Surveillance of the distribution of sand fly species is important for prediction of the risk and expansion of Leishmania infection in endemic and surrounding areas. In the present study, a simple and reliable method of typing New World Lutzomyia species circulating in endemic areas in Ecuador was established by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. PCR-RFLP of 18S ribosomal RNA (rRNA) genes with the restriction enzyme AfaI and subsequently HinfI successfully identified seven sand fly species in nine endemic areas in Ecuador. Although intraspecific genetic-diversity affecting the RFLP-patterns was detected in a species, the patterns were species specific. The method promises to be a powerful tool for the classification of New World Lutzomyia species.
  • 多良間 理絵, 加藤 大智, 石川 陽一, 宮浦 英樹, 武吉 正博, 岩田 祐之
    The Journal of Veterinary Medical Science 70 (7) 673 - 680 0916-7250 2008/07 [Refereed][Not invited]
     
    In the present study, the changes of gene expression profile in dendritic cell (DC)-derived DC2.4 cells sensitized with two allergenic chemicals were analyzed by microarray analysis to develop a basis for an in vitro assessment system of type IV allergenic chemicals. Consequently, 26 genes were significantly up-regulated, and 53 were down-regulated in both groups. Interestingly, some of up-regulated genes were associated with the maturation process of DCs. A set of genes was further evaluated by real-time reverse transcription-polymerase chain reaction to identify the gene expression changes specifically induced by type IV allergy-inducible chemicals in DC2.4 cells, and 2 possible candidates, syndecan-1 (Sdc1) and smoothened (SMO) genes were identified. Thus, up-regulation of Sdc1 gene and down-regulation of SMO gene in DC2.4 cells may be diagnostic markers for the screening of type IV-allergenic chemicals.
  • Chomar Kaung Myint, Yutaka Asato, Yu-ichi Yamamoto, Hirotomo Kato, Abdul M Bhutto, Farooq R Soomro, Muhamad Z Memon, Jun Matsumoto, Jorge D Marco, Minoru Oshiro, Ken Katakura, Yoshihisa Hashiguchi, Hiroshi Uezato
    The Journal of dermatology 35 (2) 76 - 85 0385-2407 2008/02 [Refereed][Not invited]
     
    The exact species and/or strains of Leishmania parasites involved strongly influence the clinical and epidemiological features of leishmaniasis, and current knowledge of those influences and relationships is inadequate. We report that cytochrome b (cyt b) gene sequencing identified causal Leishmania parasites of 69 cutaneous leishmaniasis cases in Pakistan over a 3-year period. Of 21 cases in highland areas (Quetta city, Balochistan province), 16 (76.2%) were identified as Leishmania (L.) tropica and five (23.8%) as Leishmania (L.) major. Of 48 cases from lowland areas, cities/villages in Indus valley in Sindh and Balochistan provinces, 47 (97.9%) were identified as L. (L.) major and one (2.1%) as L. (L.) tropica. Statistical analysis (Fisher's exact test) revealed a significant difference (P < 0.0001) in the distribution of the two species by altitude; L. (L.) major is predominant in lowland and L. (L.) tropica at highland areas. The present result enriched our earlier finding, based on the first year's cultured parasite data, that only L. (L.) tropica was found in highland areas and only L. (L.) major in lowland areas. Among Leishmania samples analyzed, three types of cyt b polymorphism of L. (L.) major were found, including 45 (86.5%) cases of type I, six (11.5%) of type II and one (2%) of type III. We report for the first time on the presence of polymorphisms in L. (L.) major (types I, II and III) based on species identification using cyt b gene sequencing from clinical samples. Moreover, we found no correlation between clinical presentation (wet-, dry- and/or mixed-types of cutaneous lesions) and causal Leishmania parasites.
  • Nozomi Shiba, Ken Maeda, Hirotomo Kato, Masami Mochizuki, Hiroyuki Iwata
    Veterinary microbiology 124 (3-4) 348 - 52 0378-1135 2007/10 [Refereed][Not invited]
     
    Feline coronavirus (FCoV) is divided into two types I and II, based on their growth in vitro and antigenicity. In this study, virus neutralization (VN) test was applied for type differentiation of FCoV infections. Sera of cats which were clinically and serologically diagnosed as feline infectious peritonitis (FIP) possessed significantly higher VN titers to type I FCoV, and sera from cats experimentally infected with FIPV type II had high VN titers to type II but not type I viruses. A total of 79 cat sera collected in the years between 2004 and 2005 were examined to evaluate seroprevalence by the VN test, showing the following results: (1) 50 cats (63.3%) were sero-positive to FCoV; (2) of the 50 FCoV positive cat serum samples, 49 (98%) showed significantly higher titers to type I virus and only one (2%) for type II virus. These results indicate that the VN test described here can be used for serological differentiation of FCoV infections of cats, and that FCoV type I is a dominant type in recent years of Japan.
  • Hirotomo Kato, Hiroshi Uezato, Eduardo A Gomez, Yoshimi Terayama, Manuel Calvopiña, Hiroyuki Iwata, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 77 (2) 324 - 9 0002-9637 2007/08 [Refereed][Not invited]
     
    Surveillance of the prevalence of Leishmania and its vector, sand fly species, in endemic and surrounding areas is important for prediction of the risk and expansion of leishmaniasis. In this study, a method for the mass screening of sand flies for Leishmania infection was established. This method was applied to 319 field-captured specimens, and 5 positive sand flies were detected. Sand fly species were identified by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) of the18S rRNA gene, and all the positive flies were Lu. hartmanni. Furthermore, cytochrome b (Cyt b) gene sequence analyses identified all the parasites as Endotrypanum species including a probable novel species. Because the method requires minimum effort and can process a large number of samples at once, it will be a powerful tool for studying the epidemiology of leishmaniasis.
  • Paola Andrea Barroso, Jorge Diego Marco, Manuel Calvopina, Hirotomo Kato, Masataka Korenaga, Yoshihisa Hashiguchi
    The Journal of antimicrobial chemotherapy 59 (6) 1123 - 9 0305-7453 2007/06 [Refereed][Not invited]
     
    OBJECTIVES: To determine the efficacy and the immunomodulatory function of Z-100 alone or combined with meglumine antimoniate on Leishmania amazonensis infection. METHODS: The effect of the compounds was evaluated by microscopic counting of intracellular amastigotes in macrophages stained with Giemsa, or axenic promastigotes, and IC(50) was determined by linear regression. The antileishmanial effect of the compounds was assessed in infected BALB/c mice by a limiting dilution analysis and the production of gamma interferon (IFN-gamma), interleukin 10 (IL-10), IL-4, IgG1 and IgG2a was measured by ELISA. RESULTS: In vitro, Z-100 showed antileishmanial activity against intracellular amastigotes of L. amazonensis with an IC(50) of 13 mg/L. Moreover, infected macrophages treated with Z-100 (12 mg/L) showed smaller parasitophorous vacuoles with fewer parasites than the control. In addition, the efficacy of Z-100 plus meglumine antimoniate [14 mg/L pentavalent antimony (Sb(v))] was higher (46% inhibition) than either Z-100 or meglumine antimoniate alone. Nevertheless, no effect of Z-100 on axenic promastigotes was observed. Infected BALB/c mice treated with Z-100 (100 microg/kg) alone did not show any antileishmanial effects in comparison with the control group, and IFN-gamma, as well as IL-10 and IL-4, was up-regulated by the treatment. In addition, both IgG1 and IgG2a were also increased by the Z-100 treatment. Although Z-100 plus meglumine antimoniate (14 or 28 mg/kg Sb(v)) controlled both the parasite load and the footpad swelling in comparison with control mice, no significant differences were found with meglumine antimoniate alone. CONCLUSIONS: In vitro, Z-100 alone or combined with meglumine antimoniate showed an antileishmanial effect on L. amazonensis. However, no effect was observed in infected BALB/c mice treated with Z-100, suggesting that the up-regulation of IL-10 and IL-4 production by the treatment could be interfering with the development of a protective Th1-type response. For further understanding of the effects of Z-100 in vivo, another strain of mice such as C57BL/6 should be tested in future.
  • P. A. Barroso, J. D. Marco, H. Kato, R. Tarama, P. Rueda, S. P. Cajal, M. A. Basombrio, M. Korenaga, N. J. Taranto, Y. Hashiguchi
    ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 101 (3) 247 - 253 0003-4983 2007/04 [Refereed][Not invited]
     
    The area around Rio Blanco, in the OrAn department in the north of the Argentinian province of Salta, is endemic for American tegumentary leishmaniasis. In an attempt to facilitate the identification of the Lutzomyia species in this area, sequences of the gene coding for the 18S ribosomal RNA (rRNA) of sandflies caught in a Shannon trap were explored, by a combination of PCR and analysis of restriction-fragment-length polymorphism (RFLP). The products from the PCR, which employed two primers developed specifically for this study (Lu.18S 1S and Lu.18S AR), were cloned into a commercial vector (pGEM-T Easy) so that their nucleotide sequences could be investigated. In the RFLP analysis, the products of single and double digestion with the AfaI and HapII restriction enzymes were separated by electrophoresis in 3% or 4% agarose. Taken together with the results of a morphological investigation of the flies, the resultant DNA fragment patterns were sufficient to identify most of the sandflies caught as Lu. neivai. Although two other species, Lu. cortelezzii and Lu. sallesi, were collected, they were relatively rare and only identified morphologically. A single digestion of the 18S-rRNA gene sequences with AfaI or HapII appeared sufficient and useful for the identification of Lu. neivai from the north of Salta province, and for several other Lutzomyia species.
  • Hirotomo Kato, Ryan C Jochim, Phillip G Lawyer, Jesus G Valenzuela
    The Journal of experimental biology 210 (Pt 5) 733 - 40 0022-0949 2007/03 [Refereed][Not invited]
     
    Two transcripts coding for an adenosine deaminase (ADA) were identified by sequencing a Phlebotomus duboscqi salivary gland cDNA library. Adenosine deaminase was previously reported in the saliva of the sand fly Lutzomyia longipalpis but it was not present in the saliva of the sand flies Phlebotomus papatasi, P. argentipes, P. perniciosus and P. ariasi, suggesting that this enzyme is only present in the saliva of sand flies from the genus Lutzomyia. In the present work, we tested the hypothesis that the salivary gland transcript coding for ADA in Phlebotomus duboscqi, a sister species of Phlebotomus papatasi, produces an active salivary ADA. Salivary gland homogenates of P. duboscqi converted adenosine to inosine, suggesting the presence of ADA activity in the saliva of this species of sand fly; furthermore, this enzymatic activity was significantly reduced when using either salivary glands of recently blood-fed sand flies or punctured salivary glands, suggesting that this enzyme is secreted in the saliva of this insect. This enzymatic activity was absent from the saliva of P. papatasi. In contrast to other Phlebotomus sand flies, we did not find AMP or adenosine in P. duboscqi salivary glands as measured by HPLC-photodiode array. To confirm that the transcript coding for ADA was responsible for the activity observed in the saliva of this sand fly, we cloned this transcript into a prokaryotic expression vector and produced a soluble and active recombinant protein of approximately 60 kDa that was able to convert adenosine to inosine. Extracts of bacteria transformed with control plasmids did not show this activity. These results suggest that P. duboscqi transcripts coding for ADA are responsible for the activity detected in the salivary glands of this sand fly and that P. duboscqi acquired this activity independently from other Phlebotomus sand flies. This is another example of a gene recruitment event in salivary genes of blood-feeding arthropods that may be relevant for blood feeding and, because of the role of ADA in immunity, it may also play a role in parasite transmission.
  • Tomoko Nishida, Osamu Nishio, Masahiko Kato, Takehisa Chuma, Hirotomo Kato, Hiroyuki Iwata, Hirokazu Kimura
    Microbiology and immunology 51 (2) 177 - 84 0385-5600 2007 [Refereed][Not invited]
     
    Norovirus (NV) is a causative agent of acute gastroenteritis in humans, and shellfishes including oysters act as major vehicles of the virus. To investigate the genetic characteristics of NVs, we collected 1,512 oysters for raw consumption between October 2002 and March 2005 from two distinct areas (area A: the Sanriku Sea area; area B: the Setouchi Sea area). We detected the capsid gene and subjected it to phylogenetic analysis. By further quantification of the copy number of the genome by using real-time PCR, the NV capcid gene was detected in approximately 5% of the oysters, and they showed wide diversity. Two percent of the oysters from area B showed relatively large number of NVs, i.e., over 100 copies of capsid gene/oyster, whereas this was not observed in area A. Most of the detected NVs from oysters and humans were genetically related when the capsid region was compared. These results suggested that NVs obtained from humans and those obtained from oysters showed a potential relationship to each other and that some populations of Japanese oysters accumulated a relatively large number of NVs.
  • 安達 聡, 橋本 知実, 武吉 正博, 加藤 大智, 岩田 祐之
    The Journal of Veterinary Medical Science 68 (12) 1281 - 1287 0916-7250 2006/12 [Refereed][Not invited]
     
    インターロイキン2(IL-2)はTh0およびTh1型ヘルパーT細胞によって放出されるT細胞の増殖因子であり、免疫反応に必須のサイトカインである。本研究において、組み換えグルタチオンS転移酵素(GST)-モルモットIL-2(GPIL-2)融合タンパク質を大腸菌(E.coli)により調製し、同タンパク質を免疫原として用いてGPIL-2に対するモノクローナル抗体(mAb)を産生し、モルモットにおける免疫反応についての研究の基礎確立を試みた。安定したハイブリドーマ細胞株3株を樹立し、E.coliにより産生した組み換えGPIL-2および組み換えバキュロウイルスに感染した昆虫細胞への各mAbの特異結合が酵素免疫測定法(ELISA)および/または免疫ブロット法により示された。これらのmAbのイソタイプ解析より、3種のmAbすべてがIgG1であり、κ鎖を有することが判明した。さらに、競合結合法によるエピトープの評価より、本研究で得られたmAbは異なる3エピトープに結合することが明らかとなった。以上、異なるGPIL-2エピトープに特異的なmAb2種に基づく、約0.3ng/mlのGPIL-2の感度閾値を有するサンドイッチELISAをGPIL-2検出用に開発した。
  • Manuel Calvopina, Rodrigo X Armijos, Jorge D Marco, Hiroshi Uezato, Hirotomo Kato, Eduardo A Gomez, Masataka Korenaga, Paola A Barroso, Tatsuyuki Mimori, Philip J Cooper, Shigeo Nonaka, Yoshihisa Hashiguchi
    BMC infectious diseases 6 139 - 139 1471-2334 2006/09 [Refereed][Not invited]
     
    BACKGROUND: Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed. METHODS: Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. RESULTS: Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. CONCLUSION: Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador.
  • Hirotomo Kato, Jennifer M Anderson, Shaden Kamhawi, Fabiano Oliveira, Phillip G Lawyer, Van My Pham, Constance Souko Sangare, Sibiry Samake, Ibrahim Sissoko, Mark Garfield, Lucie Sigutova, Petr Volf, Seydou Doumbia, Jesus G Valenzuela
    BMC genomics 7 226 - 226 1471-2164 2006/09 [Refereed][Not invited]
     
    BACKGROUND: Salivary proteins from sandflies are potential targets for exploitation as vaccines to control Leishmania infection; in this work we tested the hypothesis that salivary proteins from geographically distant Phlebotomus duboscqi sandfly populations are highly divergent due to the pressure exerted by the host immune response. Salivary gland cDNA libraries were prepared from wild-caught P. duboscqi from Mali and recently colonised flies of the same species from Kenya. RESULTS: Transcriptome and proteome analysis resulted in the identification of the most abundant salivary gland-secreted proteins. Orthologues of these salivary proteins were identified by phylogenetic tree analysis. Moreover, comparative analysis between the orthologues of these two different populations resulted in a high level of protein identity, including the predicted MHC class II T-cell epitopes from all these salivary proteins. CONCLUSION: These data refute the hypothesis that salivary proteins from geographically distinct populations of the same Phlebotomus sandfly species are highly divergent. They also suggest the potential for using the same species-specific components in a potential vector saliva-based vaccine.
  • Jorge D Marco, Abdul M Bhutto, Farooq R Soomro, Javed H Baloch, Paola A Barroso, Hirotomo Kato, Hiroshi Uezato, Ken Katakura, Masataka Korenaga, Shigeo Nonaka, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 75 (2) 261 - 6 0002-9637 2006/08 [Refereed][Not invited]
     
    Seventeen Leishmania stocks isolated from cutaneous lesions of Pakistani patients were studied by multilocus enzyme electrophoresis and by polymerase chain reaction amplification and sequencing of the cytochrome b (Cyt b) gene. Eleven stocks that expressed nine zymodemes were assigned to L. (Leishmania) major. All of them were isolated from patients in the lowlands of Larkana district and Sibi city in Sindh and Balochistan provinces, respectively. The remaining six, distributed in two zymodemes (five and one), isolated from the highland of Quetta city, Balochistan, were identified as L. (L.) tropica. The same result at species level was obtained by the Cyt b sequencing for all the stocks examined. No clear-cut association between the clinical features (wet or dry type lesions) and the Leishmania species involved was found. Leishmania (L.) major was highly polymorphic compared with L. (L.) tropica. This difference may be explained by the fact that humans may act as a sole reservoir of L. (L.) tropica in anthroponotic cycles; however, many wild mammals can be reservoirs of L. (L.) major in zoonotic cycles.
  • Manuel Calvopina, Eduardo A Gomez, Hiroshi Uezato, Hirotomo Kato, Shigeo Nonaka, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 73 (2) 281 - 4 0002-9637 2005/08 [Refereed][Not invited]
     
    In recent times, there has been an increase in the number of reports for new and rare variants of cutaneous leishmaniasis (CL). Here, we describe three unusual clinical forms of CL identified in Ecuadorian children. A total of 131 patients with CL were diagnosed over a 2-year period of active search. In 3 (2.29%), the lesions were very unusual; these included erysipeloid, recidiva cutis (LRC), and disseminated leishmaniasis (DL). The erysipeloid case is characterized by erythematous and indurated plaque seen on the face of a 5-year-old boy; the LRC one is differentiated by slowly progressing red-brown papules around large scars of healed sores in a 6-year-old girl, and the DL case is characterized by dozens of cutaneous ulcers distributed in the whole body of a 1-year-old girl. Leishmania parasites were isolated by lesion aspirate and analyzed by the technique multilocus enzyme electrophoresis (MLEE). All three isolates were identified as Leishmania (Viannia) panamensis. These distinct clinical variants rarely have been reported previously in the American cutaneous leishmaniasis, and for the first time L. (V.) panamensis was identified as the etiologic agent. Our cases extend the spectrum of clinical presentations in New World leishmaniasis.
  • Hiroshi Uezato, Hirotomo Kato, Susumu Kayo, Keisuke Hagiwara, Abdul Manan Bhutto, Ken Katakura, Shigeo Nonaka, Yoshihisa Hashiguchi
    The Journal of dermatology 32 (7) 534 - 40 0385-2407 2005/07 [Refereed][Not invited]
     
    Leishmaniasis, a zoonotic protozoan disease, starts with the inoculation of the Leishmania promastigotes into the skin at the time of blood ingestion by a female sandfly. The infection of leishmaniasis is established when the Leishmania organisms start their own intracellular multiplication after having been phagocytized by the host's macrophages. In the earliest stage of the infection, therefore, the attachment of the promastigates to the macrophages is essential. We incubated a mixed culture of macrophages (JM774-1A) and Leishmania (Leishmania) major for 6 hours in vitro and observed the process of the attachment between the parasite and host cell by scanning electron microscope. We found for the first time that the attachment between the two occurred at the site of the parasite body, in addition to the previously reported sites of the flagellar tip, flagellar base, and aflagellar tip (posterior pole).
  • 石倉 洋司, 加藤 大智, 橋本 知実, 西村 順裕, 岩田 祐之
    The Journal of Veterinary Medical Science 67 (5) 503 - 508 0916-7250 2005/05 [Refereed][Not invited]
     
    Interleukin 4 (IL-4) is an important regulatory cytokine produced by activated T lymphocytes and mast cells, and regulates the growth and differentiation of cells such as B and T lymphocytes. In the present study, recombinant thioredoxin (Trx)-porcine IL-4 (pIL-4) fusion protein was prepared by Escherichia coli (E. coli), and by using this protein as an immunogen, monoclonal antibodies (mAbs) against pIL-4 were produced to establish a basis for a research on immune responses in pigs. Six stable hybridoma cell lines were successfully established and specific binding of each mAb to recombinant pIL-4 produced by E. coli and insect cells infected with recombinant baculovirus was shown by enzyme-linked immunosorbent assay (ELISA) and/or immunoblot analysis. Isotype analyses of these mAbs revealed that the subclass of 5 out of 6 mAbs was IgG1 and the rest was IgG2b. Further, assessment of their epitopes by competition binding assay indicated that the mAbs obtained in this study bound to 4 different epitopes. The recombinant proteins and mAbs produced in this study will be useful tools for the assessment of porcine immune system.
  • Hirotomo Kato, Hiroshi Uezato, Ken Katakura, Manuel Calvopiña, Jorge D Marco, Paola A Barroso, Eduardo A Gomez, Tatsuyuki Mimori, Masataka Korenaga, Hiroyuki Iwata, Shigeo Nonaka, Yoshihisa Hashiguchi
    The American journal of tropical medicine and hygiene 72 (1) 87 - 93 0002-9637 2005/01 [Refereed][Not invited]
     
    The surveillance of prevalent Leishmania and sand fly species in endemic areas is important for prediction of the risk and expansion of leishmaniasis. In this study, we developed a polymerase chain reaction (PCR)-based method for detection of Leishmania minicircle DNA within individual sand flies. Using this method, we detected minicircle DNA in 6 (3.3%) of 183 sand flies, while 5 (3.5%) of 143 were positive for Leishmania promastigotes in the same areas by microscopic examination. The species were identified as Leishmania (Leishmania) mexicana by nucleotide sequencing of the cytochrome b gene. Additionally, all the Leishmania-positive sand flies were identified as Lutzomyia ayacuchensis by the restriction enzyme digestion of the PCR-amplified 18S ribosomal RNA gene fragments. Since this combined method is relatively easy and can process a large number of samples, it will be a powerful tool for the rapid identification of prevalent sand fly and Leishmania species as well as monitoring the infection rate in sand fly populations in endemic areas.
  • 渡辺 理恵, 長谷川 温彦, 宮沢 孝幸, 加藤 大智, 岩田 祐之
    The Journal of Veterinary Medical Science 66 (9) 1053 - 1057 0916-7250 2004/09 [Refereed][Not invited]
     
    Porcine interleukin-6 (PIL-6) protein without signal peptide was expressed as a glutathione S-transferase (GST) fusion protein in Escherichia coli. The fusion protein was expressed in an insoluble fraction, however, it was solubilized by refolding procedure using urea. From the solubilized protein, the recombinant PIL-6 (rPIL-6) was purified by a batch method using glutathione sepharose 4B and PreScission protease cleavage. By the B3B1 hybridoma cell proliferation assay, biological activity of the purified rPIL-6 was confirmed. Three monoclonal antibodies (MAbs) named 2B-1, 5A-8 and 4C-3 were generated by using the rPIL-6 as an immunogen. Immunoglobulin isotypes of the MAbs were IgG2a (4C-3) and IgG2b (2B-1 and 5A-8). For the epitope analysis, additive enzyme-linked immunosorbent assay and immunoblot analysis using deletion mutants of PIL-6 were performed. These experiments revealed that the two MAbs (2B-1 and 5A-8) recognize an overlapped epitope and the other (4C-3) recognizes a distinct epitope, and all epitopes reside in the region of aa26-64 of PIL-6.
  • Atsuhiko Hasegawa, Takashi Ohashi, Shino Hanabuchi, Hirotomo Kato, Fumiyo Takemura, Takao Masuda, Mari Kannagi
    Journal of virology 77 (5) 2956 - 63 0022-538X 2003/03 [Refereed][Not invited]
     
    Adult T-cell leukemia (ATL) occurs in a small population of human T-cell leukemia virus type 1 (HTLV-1)-infected individuals. Although the critical risk factor for ATL development is not clear, it has been noted that ATL is incidentally associated with mother-to-child infection, elevated proviral loads, and weakness in HTLV-1-specific T-cell immune responses. In the present study, using a rat system, we investigated the relationships among the following conditions: primary HTLV-1 infection, a persistent HTLV-1 load, and host HTLV-1-specific immunity. We found that the persistent HTLV-1 load in orally infected rats was significantly greater than that in intraperitoneally infected rats. Even after inoculation with only 50 infected cells, a persistent viral load built up to considerable levels in some orally infected rats but not in intraperitoneally infected rats. In contrast, HTLV-1-specific cellular immune responses were markedly impaired in orally infected rats. As a result, a persistent viral load was inversely correlated with levels of virus-specific T-cell responses in these rats. Otherwise very weak HTLV-1-specific cellular immune responses in orally infected rats were markedly augmented after subcutaneous reimmunization with infected syngeneic rat cells. These findings suggest that HTLV-1-specific immune unresponsiveness associated with oral HTLV-1 infection may be a potential risk factor for development of ATL, allowing expansion of the infected cell reservoir in vivo, but could be overcome with immunological strategies.
  • Hirotomo Kato, Kohtaro Fujihashi, Rie Kato, Taeko Dohi, Keiko Fujihashi, Yukari Hagiwara, Kosuke Kataoka, Ryoki Kobayashi, Jerry R McGhee
    International immunology 15 (2) 145 - 58 0953-8178 2003/02 [Refereed][Not invited]
     
    Our past studies showed that Peyer's patches were required for the induction of oral tolerance to the protein antigen ovalbumin (OVA), but not to the hapten 2,4,6-trinitrobenzene sulfonic acid (TNBS). In the present study, the effects of immunosenescence on oral tolerance induction were assessed with these two toleragens. Significant reductions in OVA-specific serum IgG antibody and CD4(+) T cell responses to subsequent challenge were observed in OVA-fed, young adult mice. Importantly, these reduced anti-OVA antibody responses were associated with delayed-type hypersensitivity, and antigen-induced CD4(+) T(h)1- and T(h)2-type cytokine responses. On the other hand, aged mice fed OVA failed to develop oral tolerance. Thus, CD4(+) T cells from Peyer's patches produced selected T(h)2- but no T(h)1-type cytokines. The TNP-specific serum IgG antibody and T cell responses were significantly diminished by prior TNBS feeding in young adult, 6- to 8-month-old and 12- to 14-month-old, but not in senescent, 2-year-old mice. Finally, we have directly assessed dendritic cell subsets and T cell responses in Peyer's patches, and their function in tolerance induction was impaired at an earlier stage of life. These results suggest that lack of oral tolerance to the protein OVA during aging is the result of dysfunctional Peyer's patches.
  • Takashi Ohashi, Shino Hanabuchi, Reiko Suzuki, Hirotomo Kato, Takao Masuda, Mari Kannagi
    Journal of virology 76 (14) 7010 - 9 0022-538X 2002/07 [Refereed][Not invited]
     
    Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) in infected individuals after a long incubation period. Despite the apparent transforming ability of HTLV-1 under experimental conditions, most HTLV-1 carriers are asymptomatic. These facts suggest that HTLV-1 is controlled by host immunity in most carriers. To understand the interplay between host immunity and HTLV-1-infected cells, in this study, we isolated several HTLV-1 Tax-specific cytotoxic T-lymphocyte (CTL) lines from rats inoculated with Tax-coding DNA and investigated the long-term effects of the CTL on syngeneic HTLV-1-infected T cells. Our results demonstrated that long-term mixed culture of these CTL and the virus-infected T cells led to the emergence of CTL-resistant HTLV-1-infected cells. Although the Tax expression level in these resistant cells was equivalent to that in the parental cells, expression of surface major histocompatibility complex class I (MHC-I) was significantly downregulated in the resistant cells. Downregulation of MHC-I was more apparent in RT1.A(l), which presents a Tax epitope recognized by the CTL established in this study. Moreover, peptide pulsing resulted in killing of the resistant cells by CTL, indicating that resistance was caused by a decreased epitope density on the infected cell surface. This may be one of the mechanisms for persistence of HTLV-1-infected cells that evade CTL lysis and potentially develop ATL.
  • S Hanabuchi, T Ohashi, Y Koya, H Kato, A Hasegawa, F Takemura, T Masuda, M Kannagi
    JOURNAL OF THE NATIONAL CANCER INSTITUTE 93 (23) 1775 - 1783 0027-8874 2001/12 [Refereed][Not invited]
     
    Background: Human T-cell leukemia virus type I (HTLV-1) is etiologically linked to adult T-cell leukemia (ATL). The disease has a high mortality rate and is resistant to chemotherapy; therefore, immunologic approaches to treatment could be of interest. We have previously shown that athymic rats inoculated with a syngeneic (i.e., with the same genetic background) HTLV-I-infected T-cell line (FPM1-V1AX) develop ATL-like disease and that the transfer of T cells from normal syngeneic rats immunized with FPM1-V1AX cells prevents disease development. In this study, we further characterized the host antitumor immunity to explore the possibility of peptide-based vaccination against the ATL-like disease. Methods: Immune T cells from rats immunized with FPM1-V1AX cells were analyzed for their phenotypes and cytotoxic properties. The epitope recognized by the T cells was analyzed by fine mapping. To evaluate the antitumor effects of a peptide-based vaccine, normal rats were immunized with synthetic oligopeptides corresponding to the epitope, the T cells were transferred to athymic rats inoculated with HTLV-1 infected cells, and tumor size was monitored. Results: Both CD4(+) and CD8(+) T-cell populations from rats immunized with FPM1-V1AX cells inhibited the growth of FPM1-V1AX cell-induced lymphomas in vivo. Long-term culture of splenic T cells from the immunized rats repeatedly resulted in establishment of CD8(+) HTLV-I-specific cytotoxic T lymphocyte (CTL) lines restricted to the rat major histo compatibility complex class I molecule, RT1.A(1). The cytotoxicity of these lines was directed against the HTLV-1 regulatory protein Tax and, specifically, against the epitope, amino acids 180-188 (GAFLT-NVPY). Adoptive transfer of the Tax 180-188-specific CTL line or freshly prepared T cells from rats vaccinated with the Tax 180-188 oligopeptide prevented the development of FPM1-V1AX-cell induced lymphomas in athymic rats in comparison with control groups (two rats in each group). Conclusions: This study indicated a potential therapeutic effect of peptide-based vaccination against HTLV-1-induced lymphoproliferative disease.
  • K Fujihashi, H Kato, FW van Ginkel, T Koga, PN Boyaka, RJ Jackson, R Kato, Y Hagiwara, Y Etani, Goma, I, K Fujihashi, H Kiyono, McGhee, JR
    ACTA ODONTOLOGICA SCANDINAVICA 59 (5) 301 - 308 0001-6357 2001/10 [Refereed][Not invited]
     
    Induction of mucosal immunity by oral immunization with protein antigen alone is difficult: potent mucosal adjuvants vectors, or other special delivery systems are required. Cholera toxin (CT) has been shown to be an effective adjuvant for the development of mucosal vaccines and, when given with vaccine, induces both mucosal and systemic immune responses via a Th2 cell-dependent pathway. However, and in addition to potential type-I hypersensitivity, a major concern for use of mucosal adjuvants such as CT is that this molecule is not suitable for use in humans because of its inherent toxicity. When we examined the potential toxicity of CT for the central nervous system, both CT and CT-B accumulated in the olfactory nerves/epithelium and olfactory bulbs of mice when given by the nasal route. The development of effective mucosal vaccines for the elderly is also an important issue; however, only limited information is available. When mucosal adjuvanticity of CT was evaluated in aged mice, an early immune dysregulation was evident in the mucosal immune system. The present review discusses these potential problems for effective mucosal vaccine development. Tolerance represents the most common and important response of the host to environmental antigens, including food and commensal bacterial components, for the maintenance of an appropriate immunological homeostasis. We have examined whether Peyer patches could play a more important role for the maintenance of oral tolerance. Using Peyer patch-null mice, we found that mice lacking this gut-associated lymphoid tissue retained their capability to produce secretory IgA antibodies but did not develop normal oral tolerance to protein antigens.
  • H Kato, K Fujihashi, R Kato, Y Yuki, McGhee, JR
    JOURNAL OF IMMUNOLOGY 166 (5) 3114 - 3121 0022-1767 2001/03 [Refereed][Not invited]
     
    Oral delivery of a large dose or prolonged feeding of protein Ags induce systemic unresponsiveness most often characterized as reduced Ige and IgE Ab- and Ag specific CD4+ T cell responses. It remains controversial whether oral tolerance extends to diminished mucosal IgA responses in the gastrointestinal tract. To address this issue, mice were given a high oral dose of OVA or PBS and then orally immunized with OVA and cholera toxin as mucosal adjuvant, and both systemic and mucosal immune responses were assessed. OVA-specific serum IgG and IgA and mucosa) IgA Ab levels were markedly reduced in mice given OVA orally compared with mice fed PBS, Furthermore, when OVA-specific Ah-forming cells (AFCs) in both systemic and mucosa-associated tissues mere examined, IgG AFCs in the spleen and IgA AFCs in the gastrointestinal tract lamina propria of mice given OVA orally were dramatically decreased. Furthermore, marked reductions in OVA-specific CD4+ T cell proliferative and cytokine responses in spleen and Peyer's patches were seen in mice given oral OVA but were unaffected in PBS-fed mice. We conclude that high oral doses of protein induce both mucosal and systemic unresponsiveness and that use of mucosal adjuvants that induce both parenteral and mucosal immunity may be a better way to assess oral tolerance,
  • T Koga, McGhee, JR, H Kato, R Kato, H Kiyono, K Fujihashi
    JOURNAL OF IMMUNOLOGY 165 (9) 5352 - 5359 0022-1767 2000/11 [Refereed][Not invited]
     
    Despite recent advances in the cellular and molecular analysis of induction and regulation of mucosal immune responses, little is yet known about differences which occur in aging. To address this important issue, we have compared the mucosal and systemic immune responses of aged (12- to 14-mo- or 2-year-old) and young adult (6- to 8-wk-old) C57BL/6 mice. Both aged and young mice were immunized weekly with three oral doses of 1 mg of OVA and 10 mug of cholera toxin (CT) as mucosal adjuvant. Both groups of mice over 1 or 2 years of age showed reduced levels of Ag-specific mucosal or systemic immune responses at day 21, An Ag-specific B cell enzyme-linked immunospot assay confirmed these results at the cellular level, When the Ag-induced cytokine responses were examined at both protein and mRNA levels, CD4(+) T cells from spleen and Peyer's patches of young adult mice revealed elevated levels of IL-4 production; however, these cytokine responses were significantly diminished in aged mice. In contrast to mucosal immunization, mice s.c. immunized with OVA plus CT resulted in impaired OVA-specific but intact CT B subunit-specific immune responses in 12- to 14-mo-old mice although the responses to both Ags were depressed in 2-year-old mice, These results provide the first evidence that the development of age-associated alterations possibly occurs earlier in the mucosal immune system than in the systemic immune compartment.
  • M Kannagi, T Ohashi, S Hanabuchi, H Kato, Y Koya, A Hasegawa, T Masuda, T Yoshiki
    AIDS RESEARCH AND HUMAN RETROVIRUSES 16 (16) 1737 - 1740 0889-2229 2000/11 [Refereed][Not invited]
     
    The level of host immune responses against human T cell leukemia virus type 1 (HTLV-1) varies among HTLV-1-infected individuals, In the present study, we investigate the role of host immunity on HTLV-1 leukemogenesis in vivo by using animal models. At first, we examined the effect of the routes of HTLV-1 transmission on the host anti-HTLV-1 immune responses. When immune competent adult rats were inoculated with HTLV-1-infected cells, the orally infected rats were persistently infected with HTLV-1 without humoral and cellular immune responses against HTLV-1, whereas all intravenously or intraperitoneally inoculated rats showed significant levels of immune responses. Next, we examined in vivo tumorigenicity of HTLV-1-immortalized cells in the absence of T cell immunity, by using athymic F344/N Jcl-rnu/rnu (nu/nu) rats. When inoculated into nu/nu rats, not all but some HTLV-1-immortalized rat cell lines including syngeneic FPM1-V1AX could grow and form T cell lymphoma in vivo, This syngeneic lymphoma formation was inhibited by adoptively transferred immune T cells. Furthermore, immunocompetent rats allowed in vivo growth of HTLV-1-infected lymphoma, when treated with antibodies that block costimulatory signals for T cell activation. These observations Indicated that (1) host anti-HTLV-1 immunity can be affected by the conditions of the primary infection, (2) under the low pressure of anti-HTLV-1 immunity, some HTLV-1-infected cell clones grow in vivo, and (3) T cell immunity is required for in vivo surveillance against these HTLV-1-infefted cell clones.
  • T Ohashi, S Hanabuchi, H Kato, H Tateno, F Takemura, T Tsukahara, Y Koya, A Hasegawa, T Masuda, M Kannagi
    JOURNAL OF VIROLOGY 74 (20) 9610 - 9616 0022-538X 2000/10 [Refereed][Not invited]
     
    Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) in infected individuals after a long incubation period. To dissect the mechanisms of the development of the disease, we have previously established a rat model of ATL-like disease which allows examination of the growth and spread of HTLV-1 infected tumor cells, as well assessment of the effects of immune T cells on the development of the disease. In the present study, we induced HTLV-1 Tax-specific cytotoxic T lymphocyte (CTL) immunity by vaccination with Tax-coding DNA and examined the effects of the DNA vaccine in our rat ATL-like disease model. Our results demonstrated that DNA vaccine with Tax effectively induced Tax-specific CTL activity in F344/N Jcl-rnu/+ (nu/+) rats and that these CTLs were able to lyse HTLV-1 infected syngeneic T cells in vitro. Adoptive transfer of these immune T cells effectively inhibited the in vivo growth of HTLV-1-transformed tumor in F344/N Jcl-rnu/rnu (nu/nu) rats inoculated with a rat HTLV-1 infected T cell line. Vaccination with mutant Tax DNA lacking transforming ability also induced efficient anti-tumor immunity in this model. Our results indicated a promising effect for DNA vaccine with HTLV-1 Tax against HTLV-1 tumor development in vivo.
  • Y Okai, N Nakamura, H Matsushiro, H Kato, A Setoguchi, M Yazawa, M Okuda, T Watari, A Hasegawa, H Tsujimoto
    AMERICAN JOURNAL OF VETERINARY RESEARCH 61 (9) 1122 - 1127 0002-9645 2000/09 [Refereed][Not invited]
     
    Objective-To evaluate the mechanism of multidrug resistance in feline lymphoma cell lines. Sample Population-A feline lymphoma cell line (FT-1) and its adriamycin (ADM)-resistant subline (FT-1/ADM). Procedures-The FT-1 cell line was cultivated in the presence of a gradually increasing concentration of ADM to generate its ADM-resistant subline (FT-1/ADM). Susceptibility of cells from the parental FT-1 cell line and the FT-1/ADM subline to antineoplastic drugs was determined. From the complementary DNA (cDNA) template of FT-1/ADM cells, feline MDR1 cDNA was amplified by use of polymerase chain reaction (PCR) and sequenced. Reverse transcription (RT)-PCR and Western blot analyses were performed to assess expression of the MDR1 gene and P-glycoprotein (P-gp) in FT-1/ADM cells, compared with that in FT-I cells. Results-A drug sensitivity assay revealed that FT-1/ADM cells were much more resistant to ADM and vincristine than the parental FT-1 cells. The feline MDR1 cDNA amplified by use of PCR was 3,489 irs long, corresponding to approximately 90% of the whole open reading frame of human MDR1 cDNA; its amino acid sequence was 91.5, 87.0, and 79.4% identical to that of human MDR1, mouse mdr1a, and mdr1b cDNA, respectively. By RT-PCR analysis, expression of MDR1 messenger RNA was clearly detected in FT-1/ADM cells but not in the parental FT-1 cells. Western blot analysis also revealed the expression of P-gp encoded by the MDR1 gene in FT-1/ADM cells but not in FT-1 cells. Conclusions-The basic structure of the feline MDR1 gene was essentially the same as that of multidrug-resistance genes of other species. Expression of P-gp appeared to be one of the mechanisms responsible for the development of multidrug resistance in feline lymphoma cell lines in vitro.
  • S Hanabuchi, T Ohashi, Y Koya, H Kato, F Takemura, K Hirokawa, T Yoshiki, H Yagita, K Okumura, M Kannagi
    JOURNAL OF VIROLOGY 74 (1) 428 - 435 0022-538X 2000/01 [Refereed][Not invited]
     
    Host immunity influences clinical manifestations of human T-cell leukemia virus type 1 (HTLV-1) infection. In this study, we demonstrated that HTLV-1-transformed tumors could develop in immunocompetent rats by blocking a costimulatory signal for T-cell immune responses, Four-week-old WKA/HKm rats were treated with monoclonal antibodies (MAbs) to CD80 and CD86 and subcutaneously inoculated with syngeneic HTLV-1-infected TARS-1 cells, During MAb treatment for 14 days, TARS-1 inoculation resulted in the development of solid tumors at the site of inoculation, which metastasized to the lungs. In contrast, rats not treated with MAbs promptly rejected tumor cells. Splenic T cells from MAb-treated rats indicated impairment of proliferative and cytotoxic T-lymphocyte responses against TARS-1 in vitro compared to untreated rats. However, tumors grown in MAb-treated rats regressed following withdrawal of MAb therapy. Recovery of TARS-1-specific T-cell immune responses was associated with tumor repression in these rats. Our results suggest that HTLV-1-specific cell-mediated immunity plays a critical role in immunosurveillance against HTLV-1-transformed tumor development in vivo.
  • Induction of ATL-like lymphoproliferative diseases and its inhibition by adoptive immunotheray in T-cell deficient nude rats inoculated with syngeneic HTLV-I-immortalized cells
    Ohashi T, Hanabuchi S, Kato H, Koya Y, Takemura F, Hirokawa K, Yoshiki T, Tanaka Y, Fujii M, Kannagi M
    J.Virol. 73 6031 - 6040 1999/12 [Refereed][Not invited]
  • T Tsukahara, M Kannagi, T Ohashi, H Kato, M Arai, G Nunez, Y Iwanaga, N Yamamoto, K Ohtani, M Nakamura, M Fujii
    JOURNAL OF VIROLOGY 73 (10) 7981 - 7987 0022-538X 1999/10 [Refereed][Not invited]
     
    Human T-cell leukemia virus type 1 (HTLV-1) Tax is thought to play a pivotal role in immortalization of T cells. We have recently shown that the expression of Tax protected the mouse T-cell line CTLL-2 against apoptosis induced by interleukin-2 (IL-2) deprivation and converted its growth from being IL-2 dependent to being IL-2 independent. In this study, we demonstrate that constitutive expression of bcl-xl but not bcl-2, bcl-xs, bak, bad, or bar was associated with apoptosis resistance after IL-2 deprivation in CTLL-2 cells that expressed Tax. Transient-transfection assays showed that bcl-x promoter was transactivated by wild-type Tax. Similar effects were observed in mutant Tax retaining transactivating ability through NF-kappa B. Deletion or substitution of a putative NF-kappa B binding site identified in the bcl-x promoter significantly decreased Tax-induced transactivation. This NF-kappa B-like element was able to form a complex with NF-kappa B family proteins in vitro. Furthermore, Tax-induced transactivation of the bcl-x promoter was also diminished by the mutant I kappa B alpha, which specifically inhibits NF-kappa B activity. Our findings suggest that constitutive expression of Bcl-x(L) induced by Tax through the NF-kappa B pathway contributes to the inhibition of apoptosis in CTLL-2 cells after IL-2 deprivation.
  • Y Koya, T Ohashi, H Kato, S Hanabuchi, T Tsukahara, F Takemura, KI Etoh, M Matsuoka, M Fujii, M Kannagi
    JOURNAL OF VIROLOGY 73 (8) 6436 - 6443 0022-538X 1999/08 [Refereed][Not invited]
     
    Human T-cell leukemia virus type 1 (HTLV-1) causes T-cell malignancies in a small percentage of the population infected with the virus after a long carrier state. In the present study, we established a seronegative HTLV-1 carrier state in rats inoculated with a newly established HTLV-1-infected rat T cell line, FPM1. FPM1 originated from rat thymocytes cocultured with a human HTLV-1 producer, MT-2 cells, and expressed rat CD4, CD5, CD25, and HTLV-1 Tax. However, FPM1 scarcely expressed other major HTLV-1 structural proteins and failed to induce typical antibody responses against HTLV-1 in inoculated rats. In contrast, control rats inoculated with MT-2 cells generated significant levels of anti-HTLV-1 antibodies. HTLV-1 proviruses were detected in peripheral blood cells of syngeneic rats inoculated with FPM1 for more than 1 year. Analysis of the flanking region of HTLV-1 provirus integrated inter host cells suggested that FPM1 cells remained in these animals over a relatively long period of time. However, a similar seronegative HTLV-1 carrier state was induced in the rats inoculated with mitomycin C-treated FPM1 cells and also in FPM1-inoculated allogeneic rats, suggesting that FPM1 could also transmit HTLV-1 into host cells in vivo, Our findings indicated that (i) HTLV-1-immortalized T cells which preferentially express HTLV-1 Tax persisted in vivo hut failed to induce any diseases in immunocompetent syngeneic rats and that (ii) suboptimal levels of HTLV-1 for antibody responses allowed the establishment of persistent HTLV-1 infection.
  • T Ohashi, S Hanabuchi, H Kato, Y Koya, F Takemura, K Hirokawa, T Yoshiki, Y Tanaka, M Fujii, M Kannagi
    JOURNAL OF VIROLOGY 73 (7) 6031 - 6040 0022-538X 1999/07 [Refereed][Not invited]
     
    Human T-cell leukemia virus type 1 (HTLV-1) has been shown to be the etiologic agent of adult T-cell leukemia (ATL), but the in vivo mechanism by which the virus causes the malignant transformation is largely unknown. In order to investigate the mechanisms of HTLV-1 leukemogenesis, we developed a rat model system in which ATL-like disease was reproducibly observed, following inoculation of various rat HTLV-1-immortalized cell lines. When previously established cell lines, F344-S1 and TARS-1, but not TART-1 or W7TM-1, were inoculated, systemic multiple tumor development was observed in adult nude (nu/nu) rats. FPM1 cells, newly established from a heterozygous (nu/+) rat syngeneic to nu/nu rats, caused transient tumors only at the injection site in adult nu/nu rats, but could progressively grow in newborn nu/nu rats and metastasize in lymph nodes. The derivative cell line (FPM1-V1AX) serially passed through newborn nu/nu rats acquired the potency to grow in adult nu/nu rats. These results indicated that only some with additional changes but not all of the in vitro HTLV-1-immortalized cell lines possessed in vivo tumorigenicity. Using the syngeneic system, we further showed the inhibition of tumor development by transferring splenic T cells from immunized rats, suggesting the involvement of T cells in the regression of tumors. This novel and reproducible nude rat model of human ATL would be useful for investigation of leukemogenesis and antitumor immune responses in HTLV-1 infection.
  • T Ohashi, M Kubo, H Kato, A Iwamoto, H Takahashi, M Fujii, M Kannagi
    JOURNAL OF GENERAL VIROLOGY 80 209 - 216 0022-1317 1999/01 [Refereed][Not invited]
     
    CD8(+) T lymphocytes of asymptomatic human immunodeficiency virus type 1 (HIV-1) carriers (ACs) are capable of suppressing HIV-1 replication in CD4(+) peripheral blood mononuclear cells (PBMC) by a variety of known and unknown mechanisms. In the present study, cell contact-dependent, major histocompatibility complex type I (MHC I)-unrestricted, CD8(+) cell-mediated suppression of HIV-1 LAI replication was detected. CD8+ PBMC of ACs suppressed HIV-1 replication more efficiently in MHC I-matched CD4(+) PBMC than in mismatched cells. However, even when MHC I was totally mismatched, CD8(+) cells still suppressed replication to a considerable extent in CD4(+) PBMC, This MHC I-unrestricted, CD8(+) cell-mediated HIV-1 suppression required cell contact and was not effective against cells of the established T cell line ILT-KK, In contrast, MHC I-restricted HIV-1 suppression by CD8(+) T cells was detected when ILT-KK cells were used as a target. By using these systems, we examined MHC I-restricted and -unrestricted suppressive activities of CD8(+) cells in various donors in more detail. Although both types of CD8(+) cell-mediated HIV-1 suppression diminished at the advanced stage of the infection, MHC I-unrestricted suppression diminished earlier than MHC I-restricted suppression, in parallel with the decline in CD4(+) T cells. These results suggest that suppression by the MHC I-restricted mechanism alone may fail to protect against CD4(+) T-cell loss at the late stage of infection.
  • H Matsushiro, H Kato, T Tahara, T Kato, A Iwata, T Watari, H Tsujimoto, A Hasegawa
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY 66 (3-4) 225 - 236 0165-2427 1998/12 [Refereed][Not invited]
     
    Feline thrombopoietin (TPO) was molecularly cloned to establish a basis for cytokine therapy of thrombocytopenia in cats. cDNA clones covering the whole coding sequence of feline TPO were isolated from feline liver. The feline TPO cDNA obtained in this study contained an open reading frame encoding 349 amino acid residues. The predicted amino acid sequence of feline TPO shared 78.7, 69.9, 72.9 and 83.0% similarity with sequences of human, murine, rat and canine TPO, respectively. Four cysteine residues and two of four N-glycosylation sites that are conserved among species were also found at the corresponding positions in feline TPO. The feline TPO cDNA fragment encoding the whole amino acid coding region was recloned into an expression vector, and the resulting vector was transfected into 293T cells using the calcium phosphate method. The supernatant of the transfected 293T cells stimulated the proliferation of a human megakaryoblastic leukemia cell line (UT-7/TPO) cells in a dose dependent manner, indicating that the feline TPO cDNA obtained in this study encodes biologically active feline TPO. (C) 1998 Elsevier Science B.V. All rights reserved.
  • Induction of immunological tolerance with persistent infection in adults rats by oral administration of HTLV-I
    Kato H, Koya Y, Ohashi T, Hanabuchi S, Takemura F, Fujii M, Tsujimoto H, Hasegawa A, Kannagi M
    J.Virol. 72 7289 - 7293 1998/12 [Refereed][Not invited]
  • H Kato, Y Koya, T Ohashi, S Hanabuchi, F Takemura, M Fujii, H Tsujimoto, A Hasegawa, M Kannagi
    JOURNAL OF VIROLOGY 72 (9) 7289 - 7293 0022-538X 1998/09 [Refereed][Not invited]
     
    The major route of human T-cell leukemia virus type 1 (HTLV-1) infection is mother-to child transmission caused by breast-feeding. We investigated the host immune responses to orally established persistent HTLV-1 infection in adult rats. HTLV-l-producing MT-2 cells,were inoculated into immunocompetent adult rats either orally, intravenously, or intraperitoneally. HTLV-1 proviruses were detected in the peripheral blood and several organs for at least 12 weeks. Transmission of HTLV-1 to these animals was confirmed by analysis of HTLV-1 flanking regions. Despite persistent HTLV-1 presence, none of the orally inoculated rats produced detectable levels of anti-HTLV-l antibodies, whereas all intravenously or intraperitoneally inoculated rats showed significant anti-HTLV-l antibody responses. T-cell proliferative responses against HTLV-1 were also absent in orally inoculated rats. Our findings suggest that gastrointestinal exposure of adult rats to HTLVI-infected cells induces persistent HTLV-1 infection in the absence of both humoral and cellular immune responses against HTLV-1. This immune unresponsiveness at primary infection may subsequently affect the host defense ability against HTLV-1.
  • T Ohashi, M Arai, H Kato, M Kubo, M Fujii, N Yamamoto, A Iwamoto, M Kannagi
    VIROLOGY 244 (2) 467 - 472 0042-6822 1998/05 [Refereed][Not invited]
     
    Stromal cell-derived factor 1 (SDF-1) inhibits T-cell tropic (T-tropic) HIV-1 infection in vitro. In this study, we examined the regulatory role of SDF-1 on HIV-1 replication in peripheral blood mononuclear cells (PBMC) of HIV-infected individuals. We found that the amount of SDF-1 mRNA in freshly isolated PBMC of HIV-1 carriers was higher than in healthy donors. Moreover, PBMC from some asymptomatic carriers (ACs) exhibited high levels of SDF-1 mRNA expression. The level of SDF-1 expression in PBMC did not correlate with the magnitude of CD8(+) T cell-mediated suppression of HIV-1 among ACs. SDF-1 inhibited HIV-1 replication at the viral entry step, whereas a single-cycle HIV-I infection system showed that the major part of the CD8(+) T-cell-mediated suppression occurs after intracellular penetration of the virus. Our results suggest that SDF-1 acts as a suppressor of virus replication in a CD8(+) T-cell-independent mechanism in HIV-infected individuals. (C) 1998 Academic Press.
  • H Kato, Y Koya, T Ohashi, S Hanabuchi, M Kannagi
    10TH INTERNATIONAL CONGRESS ON IMMUNOLOGY, VOLS 1 AND 2 1117 - 1121 1998 [Refereed][Not invited]
     
    The major route of human T cell leukemia virus type I (HTLV-I) infection is mother-to-child transmission caused by breast-feeding. In the present study, we investigated the host immune responses to orally inoculated HTLV-I in adult rats. HTLV-I proviruses were detected in the peripheral blood and various organs of these rats for at least 12 weeks following inoculation. Despite persistent HTLV-I, none of the orally inoculated rats showed detectable levels of antibody or T cell proliferative responses against HTLV-I, whereas intravenously or intraperitoneally inoculated rats significantly responded. These findings suggest that gastrointestinal exposure of adult rats to HTLV-I infected cells induces persistent HTLV-I infection in the absence of both humoral and cellular immune responses to HTLV-I. This immune unresponsiveness at primary infection might be one of the determinants affecting the host defense system against HTLV-I.
  • H Kato, T Ohashi, H Matsushiro, T Watari, R Goitsuka, H Tsujimoto, A Hasegawa
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY 56 (3-4) 221 - 231 0165-2427 1997/05 [Refereed][Not invited]
     
    Equine interleukin-1 receptor antagonist (IL-1ra) was molecularly cloned to establish a basis for cytokine therapy of acute and chronic inflammatory diseases in the horse. cDNA clones encoding the whole coding sequence of equine IL-1ra were isolated from equine peripheral blood mononuclear cells (PBMC) that had been stimulated with lipopolysaccharide (LPS). The equine IL-1ra cDNA obtained in this study contained an open reading frame encoding 177 amino acid residues. The predicted amino acid sequence of equine IL-1ra shared 75.7, 75.3 and 76.3% similarity with sequences of human, murine and rabbit IL-1ras, respectively, An N-glycosylation site and five cysteine residues conserved in human, murine and rabbit IL-1ras were also found at the corresponding positions in equine IL-1ra. Recombinant glutathione S-transferase (GST)-equine IL-1ra fusion protein produced by Esherichia coli was purified. This protein was shown to inhibit the cytostatic or cytotoxic activity of IL-1 on A375S2 cells, indicating that the equine IL-1ra cDNA obtained in this study encodes biologically active equine IL-1ra. (C) 1997 Elsevier Science B.V.
  • H Kato, HY Youn, T Ohashi, T Watari, R Goitsuka, H Tsujimoto, A Hasegawa
    GENE 177 (1-2) 11 - 16 0378-1119 1996/10 [Refereed][Not invited]
     
    Using lipopolysaccharide (LPS)-stimulated equine peripheral blood mononuclear cell (PBMC) cDNA as a template, we performed polymerase chain reaction (PCR) amplification with equine interleukin-1 beta (IL-1 beta) specific primers. Electrophoresis of the PCR product on agarose gel revealed an additional smaller fragment that hybridized with an equine IL-1 beta cDNA probe. Sequencing of this fragment demonstrated that it was shorter than normal equine IL-1 beta cDNA by 162 nucleotides, which corresponded to exon 5 of the human and murine IL-1 beta genes. The deletion of 162 nucleotides did not result in a frame shift but spliced out the putative exon 5 of the IL-1 beta gene which includes the cleavage site for the IL-1 beta converting enzyme (ICE) in human and murine IL-1 beta. Expression of the alternatively spliced IL-1 beta transcript in PBMC was also detected after stimulation with other compounds. These results clearly indicate the existence of an alternatively spliced IL-1 beta transcript in equine PBMC.
  • HY Youn, R Goitsuka, H Kato, DY Mason, T Watari, H Tsujimoto, A Hasegawa
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY 52 (3) 191 - 200 0165-2427 1996/07 [Refereed][Not invited]
     
    Ig-alpha of the B-cell antigen receptor complex forms a heterodimeric structure with Ig-beta on the plasma membrane of B-lymphocytes and is apparently involved in signal transduction during the activation of B-cells. Bovine leukemia virus (BLV) is predominantly a B-cell tropic retrovirus, which induces persistent lymphocytosis and leukemia/lymphoma of B-cell lineage in cattle. To understand the mechanisms of proliferation and tumorigenesis of bovine B-cells that are associated with BLV infection, we investigated the B-cell antigen receptor complex, especially bovine mb-1 encoding the bovine Ig-alpha protein. We isolated a full-length bovine mb-1 cDNA clone encoding 223 amino acid residues. The deduced amino acid sequence of the bovine mb-1 showed extensive homology with those of human and murine mb-1. The cytoplasmic tail of the bovine mb-1 also contained a consensus motif (D/E-X7-D/E-X2-L/I-X7-Y-X2-L/I) that may interact with the SH2 domain of src-type kinase. Interestingly, a similar consensus sequence motif was found in the BLV gp30(enu), although the overall sequence similarity between bovine mb-1 and BLVgp30 was not significant Furthermore, elevated levels of mb-1 transcript were detected in various bovine leukemia/lymphoma cell lines. These results indicated that the proliferation of B-cells associated with BLV-infection may be related to abnormal signal transduction through the B-cell antigen receptor complex.
  • 桃井 康行, 加藤 大智, Youn Hwa-Young
    The Journal of Veterinary Medical Science 58 (6) 537 - 541 0916-7250 1996/06 [Refereed][Not invited]
     
    Levels of granulocyte-colony stimulating factor (G-CSF) in the blood of horses were measured before and after a long-distance transportation to clarify the pathogenesis of transportation-induced fever. The serum G-CSF level was measured by its ability to stimulate growth in a mouse myeloblastic cell line, NFS-60. Of 26 horses transported for a long distance, 9 had fever more than 39.0 degrees C during or after transportation. After transportation, the serum G-CSF level significantly increased in horses with transportation-induced fever but not in those without fever, and the serum G-CSF level correlated positively with the peak body temperature and with an increase in peripheral white blood cell count. These data indicate that microbial infection, which is closely related to the elevation of the serum G-CSF level, is the causative factor of transportation-induced fever.
  • Y Nishimura, S Nakamura, N Goto, T Hasegawa, H Pang, Y Goto, H Kato, HY Youn, Y Endo, T Mizuno, Y Momoi, K Ohno, T Watari, H Tsujimoto, A Hasegawa
    ARCHIVES OF VIROLOGY 141 (10) 1933 - 1948 0304-8608 1996 [Refereed][Not invited]
     
    Feline immunodeficiency virus (FIV) was first isolated from cats with immunodeficiency syndrome. Recently, neurological abnormalities and brain lesions were shown in cats infected with FIV. To investigate the FIV genome associated with central nervous system (CNS) lesions, proviral DNA sequences from the V3-V6 region of the FIV env gene were directly amplified from uncultured necropsy tissues of a 2-year-old naturally FIV-infected cat with marked neurological symptoms and. encephalitis. By in situ hybridization, FIV RNA was detected mainly in the astrocytes. Fifteen clones isolated from cerebrum, bone marrow and lymph node samples showed only a small number of mutations or deletions in this reg:ion. A representative clone, JN-BR1, was distantly related to the previous Japanese strain (TM2) belonging to the subtype B. However, it was relatively close to the Petaluma strain which is known to infect feline brain-derived culture cells and induce brain lesions in inoculated cats. By phylogenetic analysis, the JN-BR1 strain was placed in subtype A that included Petaluma strain and several other American and European strains. The JN-BR1 strain derived from brain with encephalitis in this study and the Petaluma strain may share a common genetic structure that is related to their neuropathogenicity.
  • H KATO, Y MOMOI, K OMORI, HY YOUN, T YAMADA, N GOTO, K ONO, T WATARI, H TSUJIMOTO, A HASEGAWA
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY 49 (1-2) 161 - 168 0165-2427 1995/11 [Refereed][Not invited]
     
    A 12-year-old neutered male mixed-breed dog was referred to hospital for evaluation of chronic diarrhea. Cellulose acetate electrophoresis of its serum revealed two monoclonal peaks in the gamma-globulin fraction. On immunoelectrophoretic analysis, the two monoclonal peaks in the gamma-globulin region were strongly precipitated with anti-dog IgA serum. On sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis, the fractions corresponding to these two peaks were shown to be dimer and trimer or tetramer of immunoglobulin consisting of heavy and light chains. These results indicated that the studied dog had gammopathy with two M-components with dimer and trimer or tetramer of IgA. Accumulations of large amounts of these immunoglobulins with very high molecular weight in the serum were concluded to induce the hyperviscosity syndrome in this dog in the terminal stage.
  • H KATO, T OHASHI, N NAKAMURA, Y NISHIMURA, T WATARI, R GOITSUKA, H TSUJIMOTO, A HASEGAWA
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY 48 (3-4) 221 - 231 0165-2427 1995/10 [Refereed][Not invited]
     
    Equine interleukin-1 alpha (IL-1 alpha) and IL-1 beta were molecularly cloned to establish a basis for research on inflammatory and immune responses in the horse. Equine peripheral blood mononuclear cells (PBMC) were stimulated with lipopolysaccharide (LPS), and cDNA clones of equine IL-1 alpha and IL-1 beta covering the whole coding sequences were isolated from them. These equine IL-1 alpha and IL-1 beta clones contained open reading frames encoding 271 and 269 amino acids, respectively. The deduced amino acid sequence of equine IL-1 alpha showed 71.6% and 60.2% similarity with that of human and murine IL-1 alpha, respectively. Similarly, the amino acid sequence of equine IL-1 beta showed 66.7% and 61.8% similarity with that of human and murine IL-1 beta, respectively. In both equine IL-1 alpha and IL-1 beta, amino acids at miristoylation sites were well conserved. Dot blot analysis indicated that the expression of IL-1 beta was predominant to that of IL-1 alpha in equine PBMC stimulated with LPS or phorbol myristate acetate.
  • Y MATSUMOTO, A MOHAMED, T ONODERA, H KATO, T OHASHI, R GOITSUKA, H TSUJIMOTO, A HASEGAWA, S FURUSAWA, K YOSHIHARA, J ISHIKAWA, K HOTTA, K SUZUKI, Y HIROTA
    CYTOKINE 6 (5) 455 - 461 1043-4666 1994/09 [Refereed][Not invited]
     
    Molecular cloning of canine interleukin-8 (IL-8) was performed to establish a basis for its investigation in the canine immune system. From a cDNA pool constructed from LPS-stimulated popliteal lymph node cells, canine IL-8 cDNA covering the whole coding region was amplified by polymerase chain reaction. The nucleotide sequence of a canine IL-8 clone, designated pcIL-8#38, was highly similar to those of human, rabbit and porcine IL-8, and comprised 353 bp with an open reading frame that encoded 101 amino acids. Analysis of the deduced amino acid sequence of insert DNA in pcIL-8#38 showed 76.5, 80.2, and 87.0% similarities with human, rabbit and porcine IL-8 proteins, respectively. Insert DNA of pcIL-8#38 was transferred to a mammalian expression vector, pcDL-SR alpha 296, and transfected into Cos7 cells. The supernatant of the transfectant had neutrophil chemotactic activity when it was examined by the neutrophil migration assay, suggesting that our cloned cDNA was biologically active. The cloned canine IL-8 cDNA will be useful for canine inflammatory disease and comparative immunology research.

MISC

  • Phlebotomine sand flies in the New World
    Hirotomo Kato  有害生物  17-  61  -70  2020/10  [Not refereed][Invited]
  • 皮膚リーシュマニア症を疑われて受診し診断に難渋した好中球性皮膚症の1例
    北見 由季, 末木 博彦, 加藤 大智, 内海 大介, 山口 さやか, 高橋 健造  西日本皮膚科  82-  (2)  141  -142  2020/04
  • ハマダラカにおける性分化遺伝子の制御を受ける中腸遺伝子の解析
    山本 大介, 炭谷 めぐみ, 加藤 大智  衛生動物  71-  (Suppl.)  42  -42  2020/03
  • アジアに分布する吸血性サシガメTriatoma rubrofasciataの唾液腺トランスクリプトーム解析
    加藤 大智, 水島 大貴, Tabbabi Ahmed, 山本 大介, 角田 隆, Le Trung Kien  衛生動物  71-  (Suppl.)  50  -50  2020/03
  • マラリア自動診断システムの開発 白血球混在画像への適用評価
    原口 和音, 花房 昭彦, 早川 枝李, 加藤 大智  日本コンピュータ外科学会誌  21-  (4)  334  -334  2019/11
  • Mucosal Vaccine for Parasitic Infections
    KATO Hirotomo  Mucosal Vaccines: Innovation for Preventing Infectious Diseases  841  -854  2019/11  [Not refereed][Invited]
  • KATO Hirotomo  Med. Entomol. Zool  70-  (3)  133  -136  2019/09  [Not refereed][Invited]
  • 吸血生理の温故知新 サシチョウバエ唾液の生理活性
    加藤 大智  衛生動物  70-  (Suppl.)  32  -32  2019/03
  • Molecular mass-screening for vector research on leishmaniasis
    Kato H, Cáceres AG, Gomez EA, Hashiguchi Y  J Integrated Omics  8-  15  -16  2018/12  [Not refereed][Invited]
  • 吸血性サシガメPanstrongylus chinaiの唾液腺遺伝子転写産物の解析
    加藤 大智, Jochim Ryan C., Gomez Eduardo A., Valenzuela Jesus G., 橋口 義久  衛生動物  69-  (Suppl.)  58  -58  2018/03
  • ハマダラカにおける性分化遺伝子をノックアウトした系統の解析
    山本 大介, 炭谷 めぐみ, 加藤 大智  衛生動物  69-  (Suppl.)  59  -59  2018/03
  • 加藤大智  小児科臨床  70-  (増刊)  2272  -2282  2017/12  [Not refereed][Invited]
  • ペルー共和国で流行するハイブリッド型リーシュマニア原虫のベクター調査
    加藤 大智, アブラハム・カセレス, 橋口 義久  衛生動物  68-  (Suppl.)  57  -57  2017/03
  • 山本大介, 炭谷めぐみ, 笠嶋克巳, 瀬筒秀樹, 松岡裕之, 加藤大智  衛生動物  68-  (Suppl.)  44  -44  2017/03  [Not refereed][Not invited]
  • 加藤大智  医学のあゆみ  259-  (12-13)  1193  -1198  2016/12  [Not refereed][Not invited]
     
    吸血性節足動物は哺乳類の生体防御機構をかいくぐって吸血を行うため、長い進化・適応の過程で唾液にさまざまな生理活性物質を発達させてきており、それは血小板凝集阻害、血液凝固阻害、血管拡張、抗炎症などの作用をあわせもつ"生理活性物質のカクテル"ともいえるものである。サシチョウバエはリーシュマニア原虫を媒介する微小な吸血昆虫で、近年、その唾液に含まれるユニークな生理活性が明らかにされつつある。また、サシチョウバエの唾液は宿主免疫やリーシュマニア感染にも影響を及ぼすことが報告されており、あるときはわれわれにとって"敵"ともいえるリーシュマニア原虫の感染病態を悪化させる働きをし、またあるときは"味方"となって宿主にリーシュマニア感染に対する防御免疫を付与する。本稿ではサシチョウバエ唾液がもつ二面性について概説し、また、これまで明らかにされている唾液の生理生活物質について解説する。(著者抄録)
  • 加藤大智  西日本皮膚科  78-  (5)  553  -553  2016/10  [Not refereed][Not invited]
  • 南米アンデス地域でリーシュマニア原虫を媒介するサシチョウバエLutzomyia ayacuchensisの種内遺伝子多型解析
    加藤 大智, Caceres Abraham G., Gomez Eduardo A., 三森 龍之, 上里 博, 橋口 義久  衛生動物  67-  (Suppl.)  70  -70  2016/04
  • 次世代シーケンサーを用いた吸血性節足動物保有ウイルスの迅速・網羅的な同定
    伊澤 晴彦, 藤田 龍介, 小林 大介, 江尻 寛子, 糸川 健太郎, 山内 健生, 加藤 大智, 三條場 千寿, 小林 睦生, 佐々木 年則, 沢辺 京子  衛生動物  67-  (Suppl.)  91  -91  2016/04
  • 吸血昆虫の高度な生存戦略 唾液に含まれる生理活性物質の探索 サシチョウバエ唾液由来の新規生理活性物質の探索
    加藤 大智  衛生動物  66-  (Suppl.)  35  -35  2015/03
  • エクアドル・アンデス地域でリーシュマニア原虫を媒介するサシチョウバエLutzomyia ayacuchensisの垂直分布
    加藤 大智, Gomez Eduardo A., 三森 龍之, 橋口 義久  衛生動物  66-  (Suppl.)  72  -72  2015/03
  • サシチョウバエLutzomyia ayacuchensis唾液腺RGDペプチドAyadualinは2つの作用機序で止血機構を阻害する
    加藤 大智, Gomez Eduardo, 藤田 恵, 石丸 由佳, 岩田 祐之, 三森 龍之, 上里 博, 橋口 義久  日本獣医学会学術集会講演要旨集  157回-  369  -369  2014/08
  • 加藤 大智, Gomez Eduardo A., 藤田 恵, 石丸 由佳, 橋口 義久  衛生動物  65-  (Suppl.)  72  -72  2014/03
  • 皮膚ハエウジ症
    加藤 大智  獣医学教育モデル・コア・カリキュラム準拠「寄生虫病学」  193  -194  2014  [Not refereed][Not invited]
  • ウマバエ類、ウシバエ類、ヒツジバエ類
    加藤 大智  獣医学教育モデル・コア・カリキュラム準拠「寄生虫病学」  189  -192  2014  [Not refereed][Not invited]
  • バングラデシュにおけるイヌのバベシア感染について
    寺尾 将司, Alam Mohammaad, Akter Shirin, 中尾 亮, 櫻井 達也, 加藤 大智, 片倉 賢  日本獣医学会学術集会講演要旨集  156回-  237  -237  2013/08
  • Leishmaniasis -Field to Lab & Lab to Field-
    KATO Hirotomo  獣医寄生虫学会誌  12-  (1)  21  -31  2013/08  [Not refereed][Not invited]
  • サシチョウバエ唾液腺由来RGDペプチドによる血小板凝集阻害
    加藤 大智, 藤田 恵, 櫻井 達也, 片倉 賢, 橋口 義久  衛生動物  64-  (Suppl.)  55  -55  2013/04  [Not refereed][Not invited]
  • Vector-borne disease研究 ラボからフィールドへ リーシュマニア症 フィールドからラボへ、ラボからフィールドへ
    加藤 大智  日本獣医学会学術集会講演要旨集  155回-  117  -117  2013/03
  • バングラデシュの内臓リーシュマニア症流行地域のイヌにおけるLeishmania原虫の血清学的および分子学的エビデンス(Serological and molecular evidence of Leishmania parasite in dogs of visceral leishmaniasis endemic areas in Bangladesh)
    Alam Mohammad Zahangir, Akter Shirin, Yasin Md. Golam, 中尾 亮, 櫻井 達也, 加藤 大智, 片倉 賢  日本獣医学会学術集会講演要旨集  155回-  211  -211  2013/03
  • ガーナの皮膚リーシュマニア症流行地域に生息するSergentomyia ingramiからのLeishmania majorの初の分子同定(First Molecular Identification of Leishmania major in Sergentomyia ingrami from Cutaneous Leishmaniasis Outbreak Focus in Ghana)
    Nzelu Chukwunonso O., Desewu Kwame, Ghansah Anita, Puplampu Naiki, 櫻井 達也, Adabie-Gomez Delphina A., Wilson Michael D., 片倉 賢, 加藤 大智, Boakye Daniel A.  日本獣医学会学術集会講演要旨集  155回-  215  -215  2013/03
  • サシチョウバエLutzomyia ayacuchensis唾液腺由来の新規血小板凝集阻害物質ayadualin
    加藤 大智, 藤田 恵, 櫻井 達也, 片倉 賢, 橋口 義久  日本獣医学会学術集会講演要旨集  155回-  217  -217  2013/03
  • 多遺伝子座マイクロサテライト分析により明らかとなった中国Leishmania infantum株の遺伝子多型(Genetic polymorphism of Chinese Leishmania infantum strains revealed by multilocus microsatellite analysis)
    Alam Mohammad, 中尾 亮, 櫻井 達也, 加藤 大智, Chang K.-P., Schoenian Gabriele, 片倉 賢  日本獣医学会学術集会講演要旨集  154回-  213  -213  2012/08
  • 免疫不全aly/alyマウスの内臓リーシュマニア症における肝臓内原虫存続と制御性T細胞
    Tiwananthagorn Saruda, 加藤 大智, 櫻井 達也, 岩渕 和也, 阿戸 学, 片倉 賢  日本獣医学会学術集会講演要旨集  154回-  213  -213  2012/08
  • 吸血性サシガメTriatoma dimidiata唾液腺由来の新規血液凝固阻害物質dimiconin
    加藤 大智, 石丸 由佳, 櫻井 達也, 片倉 賢, 橋口 義久  日本獣医学会学術集会講演要旨集  154回-  203  -203  2012/08  [Not refereed][Not invited]
  • 櫻井達也, 土佐祐輔, 清水耕平, 廣田淳一, 近朋之, 加藤大智, 片倉賢  日本獣医学会学術集会講演要旨集  154回-  215  -215  2012/08  [Not refereed][Not invited]
  • 媒介昆虫からみたリーシュマニア症
    加藤 大智  西日本皮膚科  74-  (3)  309  -310  2012/06
  • ペルー・アンデス地域に分布するヒト吸血性サシチョウバエにみとめられたトリパノソーマ科原虫の自然感染
    加藤 大智, ゴメス E.A., カセレス A.G., 橋口 義久  獣医寄生虫学会誌  10-  (1-2)  51  -51  2012/03
  • 加藤大智, 加藤大智, 石丸由佳, ZHANG Feifei, 片倉賢, 橋口義久  衛生動物  63-  (Suppl.)  67  -67  2012/03  [Not refereed][Not invited]
  • 皮膚リーシュマニア症病変からの診断用病原体材料の採取法
    三森龍之, 麻生妙美, 加藤大智, Eduardo A. Gomez, 橋口義久  寄生虫学研究:材料と方法  25  -28  2012  [Not refereed][Not invited]
  • ペルー・アンデス地域に分布するヒト吸血性サシチョウバエにみとめられたトリパノソーマ科原虫の自然感染
    加藤 大智, Gomez Eduardo, Caceres Abraham, 橋口 義久  日本獣医学会学術集会講演要旨集  152回-  208  -208  2011/08
  • リーシュマニア原虫媒介サシチョウバエLutozomyia ayacuchensisの唾液腺トランスクリプトーム解析
    加藤 大智, ゴメス E., ヨキム R., 上里 博, ヴァレンズエラ J., 橋口 義久  獣医寄生虫学会誌  9-  (2)  175  -175  2011/03
  • リーシュマニア原虫媒介サシチョウバエPhlebotomus duboscqiの唾液アピラーゼの機能解析
    加藤 大智, 濱崎 亮一, 寺山 好美, 岩田 祐之, J.・ヴァレンズエラ  獣医寄生虫学会誌  9-  (1)  53  -53  2010/09
  • ペルーにおけるサシチョウバエの遺伝子タイピング法の確立
    藤田 恵, 加藤 大智, A.・カセレス, 岩田 祐之, E.・ゴメス, 橋口 義久  獣医寄生虫学会誌  9-  (1)  61  -61  2010/09
  • シャーガス病媒介サシガメTriatoma dimidiataの唾液中にみとめられたtriabin様タンパクの機能解析
    石丸 由佳, 加藤 大智, 藤田 恵, 岩田 祐之, E.・ゴメス, 橋口 義久  獣医寄生虫学会誌  9-  (1)  68  -68  2010/09
  • リーシュマニア原虫媒介サシチョウバエLutozomyia ayacuchensisの唾液腺トランスクリプトーム解析
    加藤 大智, Gomez Eduardo, Jochim Ryan, 上里 博, Valenzuela Jesus, 橋口 義久  日本獣医学会学術集会講演要旨集  150回-  194  -194  2010/09
  • サシガメTriatoma(T.)dimidiataの唾液腺トランスクリプトーム解析
    加藤 大智, R.・ヨキム, 佐古田 良, 岩田 祐之, E.・ゴメス, J.・ヴァレンズエラ, 橋口 義久  獣医寄生虫学会誌  8-  (2)  130  -130  2010/03
  • Lutzomyia属サシチョウバエrRNA遺伝子ITS領域の遺伝子多様性
    桑原 慶, 加藤 大智, E.・ゴメス, 上里 博, 三森 龍之, 山本 雄一, M.・カルボピーニャ, A.・カセレス, 岩田 祐之, 橋口 義久  獣医寄生虫学会誌  8-  (2)  131  -131  2010/03
  • リーシュマニア原虫媒介サシチョウバエPhlebotomus duboscqiの唾液アピラーゼの機能解析
    加藤 大智, 濱崎 亮一, 寺山 好美, 岩田 祐之, Valenzuela Jesus  日本獣医学会学術集会講演要旨集  149回-  237  -237  2010/03
  • ペルーにおけるサシチョウバエの遺伝子タイピング法の確立
    藤田 恵, 加藤 大智, Caceres Abraham, 岩田 祐之, Gomez Eduardo, 橋口 義久  日本獣医学会学術集会講演要旨集  149回-  239  -239  2010/03
  • シャーガス病媒介サシガメTriatoma dimidiataの唾液中にみとめられたtriabin様タンパクの機能解析
    石丸 由佳, 加藤 大智, 藤田 恵, 岩田 祐之, Gomez Eduardo, 橋口 義久  日本獣医学会学術集会講演要旨集  149回-  241  -241  2010/03
  • Hirotomo Kato, Eduardo A. Gomez, Abraham G. Caceres, Hiroshi Uezato, Tatsuyuki Mimori, Yoshihisa Hashiguchi  INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH  7-  (3)  814  -826  2010/03  [Not refereed][Not invited]
     
    Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.
  • Lutzomyia属サシチョウバエrRNA遺伝子ITS領域の遺伝子多様性
    桑原 慶, 加藤 大智, Gomez Eduardo, 上里 博, 三森 龍之, 山本 雄一, Calvopina Manuel, Caceres Abraham, 岩田 祐之, 橋口 義久  日本獣医学会学術集会講演要旨集  148回-  183  -183  2009/09
  • 加藤 大智, 寺山 好美, Gomez Eduardo A., 上里 博, Calvopina Manuel, 岩田 祐之, 橋口 義久  衛生動物  60-  (2)  157  -157  2009/06
  • サシガメTriatoma dimidiataの唾液腺トランスクリプトーム解析
    加藤 大智, Jochim Ryan, 佐古田 良, 岩田 祐之, Gomez Eduardo, Valenzuela Jesus, 橋口 義久  衛生動物  60-  (Suppl.)  49  -49  2009/04
  • サシチョウバエ唾液成分を用いたリーシュマニア感染防御ワクチンの候補抗原の探索
    加藤 大智, J.・ヴァレンスエラ  獣医寄生虫学会誌  7-  (1)  46  -46  2008/10
  • リーシュマニア原虫感染サシチョウバエのマススクリーニング法の開発と南米アンデスの疾患流行地での疫学調査への応用
    加藤 大智, Caceres Abraham, Gomez Eduardo, 三森 龍之, 上里 博, 岩田 祐之, 橋口 義久  衛生動物  59-  (Suppl.)  56  -56  2008/04
  • サシチョウバエ唾液成分を用いたリーシュマニア感染防御ワクチンの候補抗原の探索
    加藤 大智, Valenzuela Jesus  日本獣医学会学術集会講演要旨集  145回-  186  -186  2008/03
  • 南米アンデス地域のリーシュマニア症流行地におけるサシチョウバエの分子疫学調査
    加藤 大智, Caceres Abraham G., Gomez Eduardo A., 三森 龍之, 上里 博, 寺山 好美, Calvopina Manuel, 岩田 祐之, 橋口 義久  獣医寄生虫学会誌  6-  (2)  108  -108  2008/03
  • 寺田豊, 芝希望, 前田健, 水野拓也, 甲斐一成, 望月雅美, 加藤大智, 岩田祐之  日本獣医学会学術集会講演要旨集  146th-  2008
  • リーシュマニア原虫感染サシチョウバエの大量スクリーニング系の確立
    加藤 大智, 上里 博, E.・ゴメス, 寺山 好美, M.・カルボピーニャ, 岩田 祐之, 橋口 義久  獣医寄生虫学会誌  6-  (1)  46  -46  2007/12
  • エクアドルにおけるサシチョウバエの遺伝子タイピング法の確立
    寺山 好美, 加藤 大智, E.・ゴメス, 上里 博, M.・カルボピーニャ, 岩田 祐之, 橋口 義久  獣医寄生虫学会誌  6-  (1)  47  -47  2007/12
  • ベクター唾液成分を用いたリーシュマニア感染防御ワクチンの開発に向けて
    加藤 大智  獣医寄生虫学会誌  6-  (1)  1  -6  2007/12  [Not refereed][Not invited]
  • 南米アンデス地域のリーシュマニア症流行地におけるサシチョウバエの分子疫学調査
    加藤 大智, Abraham Caceres, Eduardo Gomez, 三森 龍之, 上里 博, 寺山 好美, Manuel Calvopina, 岩田 祐之, 橋口 義久  日本獣医学会学術集会講演要旨集  144回-  65  -65  2007/08
  • 若手研究者による獣医寄生虫学の新展開 ベクター唾液成分を用いたリーシュマニア感染防御ワクチンの開発に向けて
    加藤 大智  日本獣医学会学術集会講演要旨集  143回-  96  -96  2007/03
  • リーシュマニア原虫感染サシチョウバエの大量スクリーニング系の確立
    加藤 大智, 上里 博, Gomez Eduardo, 寺山 好美, Calvopina Manuel, 岩田 祐之, 橋口 義久  日本獣医学会学術集会講演要旨集  143回-  172  -172  2007/03
  • エクアドルにおけるサシチョウバエの遺伝子タイピング法の確立
    寺山 好美, 加藤 大智, Gomez Eduardo, 上里 博, Calvopina Manuel, 岩田 祐之, 橋口 義久  日本獣医学会学術集会講演要旨集  143回-  173  -173  2007/03
  • ウイルス中和試験を用いたネココロナウイルス感染の血清疫学的解析
    芝 希望, 前田 健, 加藤 大智, 望月 雅美, 岩田 祐之  日本獣医学会学術集会講演要旨集  143回-  186  -186  2007/03
  • IV型アレルギー誘発性化学物質によって樹状細胞に誘導される遺伝子変動の解析
    多良間 理絵, 加藤 大智, 石川 陽一, 武吉 正博, 岩田 祐之  日本獣医学会学術集会講演要旨集  143回-  201  -201  2007/03
  • リーシュマニア媒介サシチョウバエPhlebotomus duboscqiの唾液中にみとめられたadenosine deaminase活性
    加藤 大智, R.・ヨキム, 岩田 祐之, J.・ヴァレンスエラ  獣医寄生虫学会誌  5-  (2)  46  -46  2007/03
  • パキスタンにおける皮膚リーシュマニア症の血清診断と抗原分析
    谷口 祥介, 長内 由利子, 松本 淳, 上里 博, 加藤 大智, Bhutto A.M., Soomro F.R., Marco J.D., Barroso P.A., 橋口 義久, 片倉 賢  獣医寄生虫学会誌  5-  (2)  56  -56  2007/03
  • 芝希望, 前田健, 清田曜子, 甲斐一成, 平田真, 平田由美, 岩田美喜, 加藤大智, 望月雅美, 岩田祐之  山口県獣医学会講演抄録  46th-  2007
  • Antigenic analysis of salivary proteins in Leishmania-transmissible sand fly, Phlebotomus duboscqi.
    Kato H, Anderson J, Oliveira F, Valenzuela J  Tropical Medicine and Health  35-  (2)  204  2007  [Not refereed][Not invited]
  • Trypanosoma cruzi Infection in an Area Endemic for Leishmaniasis in Ecuador: Seroepidemiological Survey of Canine and Human Infection in the Ecuadorian Amazonian Region.
    Guevara AG, Atherton RRD, Wauters M, Kato H, Yamamoto Y, Gebb M, Calvopina M, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  220  -225  2007  [Not refereed][Not invited]
  • A Brief Note on the American Cutaneous Leishmaniasis at an Andean Community, Lanca, Province of Huarochiri, Department of Lima, Peru.
    Hashiguchi Y, Caceres AG, Criollo ML, Gomez EAL, Yamamoto Y, Kato H  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  203  -208  2007  [Not refereed][Not invited]
  • A Preliminary Survey of American Cutaneous Leishmaniasis at Andean Endemic Areas, Huaranchal, La Cuesta and Nambuque, Province of Otuzco, Department of La Libertad, Peru.
    Hashiguchi Y, Vargas FV, Cordova O, Gomez EAL, Kato H, Mimoro T, Yamamoto Y, Uezato H  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  194  -202  2007  [Not refereed][Not invited]
  • American Cutaneous Leishmaniasis at an Andean Endemic Area, Province of Huaura, Department of Lima, Peru: a Preliminary Study.
    Hashiguchi Y, Caceres AG, Gomez EAL, Kato H, Yamamoto Y, Rondan JR, Carbajal FC, Jesenia LEA  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  186  -193  2007  [Not refereed][Not invited]
  • Comparison of Diffuse (DCL) and Disseminated (DSCL) Cutaneous Leishmaniasis: an Overview of Cases Observed in Ecuador, and a Brief Comment.
    Hashiguchi Y, Gomez EAL, Uezato H, Kato H, Mimori T, Flor T, Muzzio J, Wong Chum YY, Martini L  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  175  -185  2007  [Not refereed][Not invited]
  • A Case Report of Cutaneous Leishmaniasis Caused by Leishmania (Viannia) guyanensis, Resistant to Antimonial Chemotherapy but Cured with Later Cryosurgery in Ecuador.
    Gomez EAL, Briones MI, Ibarra LV, Almeida RF, Flor T, Muzzio J, Wong Chum YY, Sud RA, Kato H, Uezato H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  163  -168  2007  [Not refereed][Not invited]
  • Visceral Leishmaniasis in Ecuador: Seroepidemiological Survey of Human and Canine Infection in the Ecuadorian Amazon. – Pilot Study –
    Calvopina M, Atherton RRD, Kato H, Yamamoto Y, Gebb M, Guevara AG, Hashiguchi Y  tudies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  157  -162  2007  [Not refereed][Not invited]
  • Identification of Leishmania Species from Patient’s Cutaneous Lesions and Sandfly Specimens by Molecular Biological Methods. – Application of FTA Card for Field Researches on Leishmaniasis –
    Kato H, Vargas FV, Cordova O, Gomez EAL, Mimori T, Yamamoto Y, Guevara AG, Calvopina M, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  142  -156  2007  [Not refereed][Not invited]
  • Why are There so Many Differences in “Uta” between Peruvian and Ecuadorian Regions of the Andes? – A Brief Bibliographic Review and Comments –
    Hashiguchi Y, Gomez EAL, Kato H, Mimori T, Uezato H  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  112  -132  2007  [Not refereed][Not invited]
  • Lutzomyia spp. at Llaucano Valley, Chota Province, Department of Cajamarca, Peru, an Area Endemic for Cutaneous Leishmaniasis.
    Zorrilla V, Caceres AG, Cabanillas E, Alarcon J, Tejada A, Kato H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  82  -93  2007  [Not refereed][Not invited]
  • Molecular Typing of Sandfly Species from Areas Endemic for Leishmaniasis in Ecuador by PCR-RFLP of 18S Ribosomal RNA Gene.
    Terayama Y, Kato H, Gomez EA, Uezato H, Calvopiña M, Iwata H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  60  -72  2007  [Not refereed][Not invited]
  • Establishment of a Mass Screening Method of Leishmania Infection within Individual Sandflies.
    Kato H, Uezato H, Gomez EA, Terayama Y, Calvopiña M, Iwata H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  47  -59  2007  [Not refereed][Not invited]
  • A Phylogenic Analysis of the Genus Leishmania by Cytochrome b Gene Sequencing.
    Asato Y, Myint CK, Yamamoto Y, Oshiro M, Kato H, Marco JD, Mimori T, Gomez EAL, Uezato H, Nonaka S, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  28  -38  2007  [Not refereed][Not invited]
  • Polymorphisms of Cytochrome b gene in Causative Parasites and their Relation to the Types of Cutaneous Leishmaniasis-Lesions in Pakistan
    Myint CK, Asato Y, Yamamoto Y, Kato H, Bhutto AM, Soomro FR, Memon MZ, Matsumoto J, Marco JD, Oshiro M, Katakura K, Uezato H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  8-  12  -27  2007  [Not refereed][Not invited]
  • リーシュマニア原虫媒介サシチョウバエPhlebotomus(P.)duboscqi唾液タンパクのトランスクリプトーム解析
    加藤 大智, J.・アンダーソン, F.・オリヴェイラ, J.・ヴァレンスエラ  獣医寄生虫学会誌  5-  (1)  30  -30  2006/12
  • リーシュマニア媒介サシチョウバエPhlebotomus duboscqiの唾液中にみとめられたadenosine deaminase活性
    加藤 大智, Jochim Ryan, 岩田 祐之, Valenzuela Jesus  日本獣医学会学術集会講演要旨集  142回-  67  -67  2006/08
  • パキスタンにおける皮膚リーシュマニア症の血清診断と抗原分析
    谷口 祥介, 長内 由利子, 松本 淳, 上里 博, 加藤 大智, Bhutto A.M., Soomro F.R., Marco J.D., Barroso P.A., 橋口 義久, 片倉 賢  日本獣医学会学術集会講演要旨集  142回-  70  -70  2006/08
  • 加藤 大智, Anderson Jennifer, Oliveira Fabiano, Valenzuela Jesus  衛生動物  57-  (Suppl.)  48  -48  2006/03
  • リーシュマニア原虫媒介サシチョウバエPhlebotomus(P.)duboscqi唾液タンパクのトランスクリプトーム解析
    加藤 大智, Anderson Jennifer, Oliveira Fabiano, Valenzuela Jesus  日本獣医学会学術集会講演要旨集  141回-  205  -205  2006/03
  • 上里博, 加藤大智, BHUTTO A M, SOOMRO F R, MEMON M Z, TAREEN M I, TAREEN I K, 片倉賢, 野中薫雄, 橋口義久  Trop Med Health  33-  (Suppl.)  69  -69  2005/09  [Not refereed][Not invited]
  • 片倉賢, 山本菜緒, 松本淳, 野中薫雄, 上里博, 加藤大智, BHUTTO Abdul, BHUTTO Abdul, SOOMRO Farooq, SOOMRO Farooq, MARCO Jorge, BARROSO Paola, 橋口義久  日本獣医学会学術集会講演要旨集  140th-  89  -89  2005/08  [Not refereed][Not invited]
  • イヌジステンパーウイルスKDK-1株のゲノム全塩基配列
    小野 哲嗣, 井口 かおり, 前田 健, 加藤 大智, 岩田 祐之, 望月 雅美  日本獣医学会学術集会講演要旨集  140回-  106  -106  2005/08
  • ネコのa1酸性糖蛋白の分離とモノクローナル抗体の作製
    岡田 千織, 加藤 大智, 前田 健, 岩田 祐之, 望月 雅美  日本獣医学会学術集会講演要旨集  140回-  184  -184  2005/08
  • 加藤大智, 上里博, 片倉賢, CALVOPINA M, MARCO J D, BARROSO P A, 三森龍之, 是永正敬, 野中薫雄  Trop Med Health  32-  (Suppl.)  85  -85  2004/09  [Not refereed][Not invited]
  • 上里博, 加藤大智, ABDUL M B, 片倉賢, 野中薫雄, 橋口義久  Trop Med Health  32-  (Suppl.)  83  -83  2004/09  [Not refereed][Not invited]
  • イバラキウイルスの構造蛋白VP1の遺伝子解析
    南 奈津子, 加藤 大智, 岩田 祐之  日本獣医学会学術集会講演要旨集  138回-  94  -94  2004/08
  • A Revisit of Current Dogma for the Cellular and Molecular Basis of Oral Tolerance
    Fujihashi K, Kato H, McGhee JR  The Intestinal Mucosa and Dietary Antigens / Oral Tolerance  2004/07  [Not refereed][Not invited]
  • In vitro activity of Z-100, an immuno-modulatory polysaccharide, against Leishmania (Leishmania) amazonesis.
    Barroso PA, Marco JD, Korenaga M, Calvopina M, Kato H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  148  -153  2004  [Not refereed][Not invited]
  • Epidemiology of leishmaniasis in Pakistan and a literature review.
    Bhutto AM, Soomro FR, Shah SSA, Solangi A, Ahmed R, Uezato H, Kato H, Katakura K, Nonaka S, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  119  -130  2004  [Not refereed][Not invited]
  • Clinical features, parasites and geographical distribution of American tegumentary leishmaniasis in Ecuador.
    Calvopina M, Uezato H, Gomez EAL, Kato H, Mimori T, Nonaka S, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  86  -97  2004  [Not refereed][Not invited]
  • Detection of Leishmania in peripheral blood of domestic dogs from the areas endemic for cutaneous leishmaniasis in Ecuadorby PCR and Southern hybridization.
    Kato H, Calvopina M, Gomez EAL, Sud RA, Nonaka S, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  70  -77  2004  [Not refereed][Not invited]
  • Are sandflies spreading gradually to the urban area of Larkana city? – an information and consideration –
    Barroso PA, Bhutto AM, Kato H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  59  -67  2004  [Not refereed][Not invited]
  • Establishment of a detection and identification method of Leishmania species within naturally infected individual sandflies.
    Kato H, Uezato H, Katakura K, Calvopina M, Marco JD, Barroso PA, Gomez EAL, Mimori T, Korenaga M, Iwata H, Nonaka H, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  30  -43  2004  [Not refereed][Not invited]
  • Observation on the attachment and entry of Leishmania (Leishmania) major to macrophages by scanning microscope.
    Uezato H, Kato H, Bhutto AM, Nonaka S, Hashiguchi Y  Studies on New and Old World leishmaniases and its transmission, with particular reference to Ecuador, Argentina and Pakistan. Hashiguchi, Y. ed. Kochi, Japan: Kyowa Printing Co., Research Report Series  7-  10  -17  2004  [Not refereed][Not invited]
  • 豚インターロイキン4の組換えタンパク発現とモノクローナル抗体の作製
    石倉 洋司, 安達 聡, 加藤 大智, 岩田 祐之  日本獣医学会学術集会講演要旨集  135回-  111  -111  2003/03
  • A Hasegawa, T Ohashi, S Hanabuchi, K Kurihara, K Komori, H Kato, N Harashima, T Masuda, M Kannagi  AIDS RESEARCH AND HUMAN RETROVIRUSES  19-  S16  -S17  2003  [Not refereed][Not invited]
  • 長谷川温彦, 大橋貴, 花淵志野, 原嶋奈々江, 加藤大智, 栗原清, 野村真知子, 増田貴夫, 神奈木真理  日本免疫学会総会・学術集会記録  32-  190  -190  2002/10  [Refereed][Not invited]
  • ラットHTLV-I腫瘍モデルにおけるHTLV-I特異的CTL認識エピトープの同定とペプチドワクチンの抗腫瘍効果
    花渕 志野, 大橋 貴, 加藤 大智, 長谷川 温彦, 神奈木 真理  日本免疫学会総会・学術集会記録  31-  115  -115  2001/12
  • H Kato, K Fujihashi, R Kato, McGhee, JR  FASEB JOURNAL  15-  (4)  A367  -A367  2001/03  [Not refereed][Not invited]
  • K Fujihashi, PD Rennert, H Kato, K Fujihashi, McGhee, JR  FASEB JOURNAL  15-  (4)  A368  -A368  2001/03  [Not refereed][Not invited]
  • R Kato, K Fujihashi, H Kato, McGhee, JR  FASEB JOURNAL  15-  (4)  A371  -A371  2001/03  [Not refereed][Not invited]
  • H Kato, R Kato, K Fujihashi, McGhee, JR  ANTIBODIES IN VIRAL INFECTION  260-  201  -228  2001  [Not refereed][Not invited]
  • T Koga, McGhee, JR, H Kato, R Kato, H Kiyono, K Fujihashi  JOURNAL OF IMMUNOLOGY  165-  (12)  7338  -7338  2000/12  [Not refereed][Not invited]
  • H Kato, K Fujihashi, R Kato, McGhee, JR  FASEB JOURNAL  14-  (6)  A1198  -A1198  2000/04  [Not refereed][Not invited]
  • R Kato, K Fujihashi, H Kato, McGhee, JR  FASEB JOURNAL  14-  (6)  A1202  -A1202  2000/04  [Not refereed][Not invited]
  • T Koga, McGhee, JR, H Kato, R Kato, H Kiyono, K Fujihashi  FASEB JOURNAL  14-  (6)  A1202  -A1202  2000/04  [Not refereed][Not invited]
  • 小動物の造血器腫瘍細胞株における薬剤排出能による薬剤耐性の評価
    中村 倫子, 岡井 佳子, 加藤 大智, 鶴尾 隆, 増田 健一, 大野 耕一, 辻本 元  日本獣医学会学術集会講演要旨集  129回-  141  -141  2000/03
  • M Kannagi, T Ohashi, S Hanabuchi, H Kato, Y Koya, T Yoshiki  LEUKEMIA  14-  (3)  551  -551  2000/03  [Not refereed][Not invited]
  • HTLV-Iの実験的経口接種による持続感染と免疫不応答
    加藤 大智, 神奈木 真理  臨床免疫  33-  (1)  74  -79  2000/01  [Not refereed][Not invited]
  • 組換えワクシニアウイルスを用いた抗HTLV-I腫瘍免疫の検討
    小屋 美博, 大橋 貴, 加藤 大智, 花渕 志野, 竹村 富美代, 鷲山 美樹, 神奈木 真理  日本免疫学会総会・学術集会記録  29-  322  -322  1999/10
  • ラットのATLモデル系を用いたHTLV-I Taxに対するDNAワクチンの有効性の解析
    大橋 貴, 竹村 富美代, 花渕 志野, 加藤 大智, 小屋 美博, 塚原 智典, 神奈木 真理  日本免疫学会総会・学術集会記録  29-  128  -128  1999/10
  • ネコのリンパ腫由来細胞株における各種薬剤の多剤耐性克服効果
    中村 倫子, 岡井 佳子, 加藤 大智, 中山 章, 鶴尾 隆, 増田 健一, 辻本 元  日本獣医学会学術集会講演要旨集  128回-  184  -184  1999/09
  • ラットモデルにおけるヒトT細胞白血病ウイルスI型(HTLV-I)感染細胞の腫瘍形成と宿主免疫
    神奈木 真理, 大橋 貴, 花渕 志野, 加藤 大智, 小屋 美博, 廣川 勝いく, 松岡 雅雄, 吉木 敬  日本癌学会総会記事  58回-  447  -447  1999/08  [Not refereed][Not invited]
  • 同系ラット生体内における移入HTLV-I感染細胞の長期生存
    小屋 美博, 大橋 貴, 加藤 大智, 花渕 志野, 塚原 智典, 江藤 健一郎, 松岡 雅雄, 神奈木 真理  日本臨床免疫学会会誌  (26回抄録集)  105  -105  1998/10
  • HTLV-I経口感染ラットにおいて認められる持続感染と免疫不応答
    加藤 大智, 小屋 美博, 大橋 貴, 花渕 志野, 神奈木 真理  日本臨床免疫学会会誌  (26回抄録集)  177  -177  1998/10
  • ヌードラットを用いた成人T細胞白血病(ATL)モデルの作出
    大橋 貴, 花渕 志野, 加藤 大智, 小屋 美博, 広川 勝いく, 吉木 敬, 神奈木 真理  日本臨床免疫学会会誌  (26回抄録集)  177  -177  1998/10
  • KOYA YOSHIHIRO, OHASHI TAKASHI, KATO HIROTOMO, HANABUCHI SHINO, TSUKAHARA TOMONORI, ETO KEN'ICHIRO, MATSUOKA MASAO, KANNAGI MARI  日本免疫学会総会・学術集会記録  28-  (26回抄録集)  105  -105  1998/10  [Not refereed][Not invited]
  • ネコのリンパ腫細胞における多剤耐性とmdr1遺伝子の発現
    岡井 佳子, 中村 倫子, 松代 はるか, 加藤 大智, 亘 敏広, 辻本 元, 長谷川 篤彦  日本獣医学会学術集会講演要旨集  125回-  243  -243  1998/03
  • 馬のIL-1 receptor antagonistのクローニング
    加藤 大智  日本獣医学会学術集会講演要旨集  121回-  230  -230  1996/04
  • 二峰性M蛋白血症を示したIgA型多発性骨髄腫のイヌの一例
    加藤 大智  日本獣医師会雑誌  48-  (5)  344  -344  1995/05

Awards & Honors

  • 2009/10 Japanese Society of Tropical Medicine JSTM Young Investigator’s Award
     
    受賞者: KATO Hirotomo

Research Grants & Projects

  • 吸血昆虫の囲食膜の機能解明とバリア機能強化による病原体伝播阻止法の開発
    日本学術振興会:科学研究費助成事業 挑戦的研究(萌芽)
    Date (from‐to) : 2021/07 -2024/03 
    Author : 加藤 大智
  • Transmission mechanisms of vector-borne pathogens by blood-sucking insects
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2020/04 -2024/03 
    Author : 加藤 大智, 新井 明治, 水島 大貴, 山本 大介
  • リーシュマニア症およびシャーガス病の感染・病態リスク評価系の構築
    文部科学省:科学研究費補助金(基盤研究(A))
    Date (from‐to) : 2017/04 -2022/03 
    Author : 加藤 大智
  • 吸血昆虫の腸内フローラは病原体媒介能を決定する因子になるのか?
    文部科学省:科学研究費補助金(挑戦的研究(萌芽))
    Date (from‐to) : 2018/07 -2021/03 
    Author : 加藤 大智
  • タイにおける新興リーシュマニア症の伝播疫学調査
    Heiwa Nakajima Foundation:grant in aid
    Date (from‐to) : 2018/04 -2019/03 
    Author : KATO Hirotomo
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2015/04 -2019/03 
    Author : Kato Hirotomo
     
    In the study on the sand fly saliva, a peptide having inhibitory effects on both platelet aggregation and coagulation was characterized. The peptide also showed anti-complement activity, an important player in innate immunity. In addition, salivary proteins with different number of repeated sequences were identified, and their anticoagulant activities were correlated with the number of repeated sequences. In the study on the kissing bug saliva, salivary gland transcriptome analyses were performed on Panstrongylys chinai and an Asian kissing bug, Triatoma rubrofasciata. Of variety of potential novel bioactive agents, characteristic Kazal-type protease inhibitors were identified. One of them was characterized as an anticoagulant by inhibiting the enzymatic activity.
  • リーシュマニア症の迅速・簡便な分子診断法の確立と応用
    大山健康財団:学術研究助成
    Date (from‐to) : 2017/04 -2018/03 
    Author : 加藤 大智
  • マダニのセンサー機能分子の探索
    大下財団:研究助成
    Date (from‐to) : 2017/04 -2018/03 
    Author : 加藤 大智
  • リーシュマニア症の伝播および病態の解明に向けた新規リスク評価システムの構築
    文部科学省:科学研究費補助金(基盤研究(A))
    Date (from‐to) : 2013/04 -2017/03 
    Author : 加藤 大智
  • 新興感染症Leishmania siamensis 感染症の迅速診断法の開発
    学術振興会:科学研究費補助金(外国人特別研究員奨励費)
    Date (from‐to) : 2013/10 -2015/09 
    Author : 加藤 大智
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2012/04 -2015/03 
    Author : KATAKURA Ken, KATO Hirotomo, TAKIGUCHI Mitsuyoshi, ATO Manabu
     
    Visceral leishmaniasis (VL) in humans in the Indian subcontinent is caused by infection with Leishmania donovani and the transmission is thought to be anthroponotic. The prevalence of L. donovani infection and the role of VL transmission in dogs have not been well investigated. The present epidemiological study showed that approximately 10% of stray dogs were serological or PCR positive in the blood in a VL endemic area in Bangladesh, but no severe clinical symptoms were observed. Experimental infection of beagle dogs with L. donovani showed that no remarkable changes were detected in clinical sings, hematological and serum biochemical values, and peripheral T lymphocyte subpopulations. Although these dogs were negative for PCR examinations, antibodies were detected during the experimental period. Taken together, the results suggest that dogs infected with L. donovani maintain the latent infection, but serve as the reservoir animal for the transmission of human VL.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    Date (from‐to) : 2011/04 -2015/03 
    Author : HASHIGUCHI YOSHIHISA, KORENAGA Masataka, UEZATO Hiroshi, MIMORI Tatsuyuki, ITO Makoto, KATO Hirotomo, GOMEZ Eduardo, VELEZ Lenin, SUD Roberto, MARTINI Luigi, CALVOPINA Manuel, VARGAS Franklin, CACERES Abraham, MARCO Diego, ANDREA Paola
     
    Leishmaniasis is one of the protozoan infectious diseases transmitted by blood-sucking insects, sandflies. The disease is widely distributed, affecting at least 12 million people in 98 countries of the world. In this study, three disease factors (patients, vector sandflies, and reservoir animals) were investigated by employing molecular biological, immunological and epidemiological methods. Main results obtained are as follows: (1) relation between Leishmania spp. and disease forms, (2) determination of vector species, (3) search for different mammals infected with Leishmania, (4) development of rapid diagnosis and treatment, (5) search for control measures at each endemic area.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2010/04 -2014/03 
    Author : KATAKURA Ken, SAKURAI Tatsuya, MIYAZAKI Satoshi, KATO Hirotomo, MATSUURA Hideyuki, ITAGAKI Tadashi, SASAKI Hitoshi
     
    Epidemiological surveys of livestock parasites, including Babesia, Theileria, Trypanosoma, Toxoplasma, Neospora and Fasciola species, were conducted in Myanmar. The results revealed new insights of distribution, life cycle and evolution of these parasites. On the other hand, isolation and characterization of antitrypanosomal compounds from Myanmar medicinal plants was performed to utilize natural plant products for treatment and prophylaxis of parasitic disease. Results of this study will contribute to establishment of control strategies of parasitic diseases and development of animal husbandry in Myanmar.
  • 吸血昆虫唾液由来の新規RGDペプチドを応用した抗血栓薬の開発研究
    科学技術振興機構:研究成果最適展開支援事業(A-STEP)
    Date (from‐to) : 2012/11 -2013/10 
    Author : 加藤 大智
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2011 -2013 
    Author : KATO HIROTOMO
     
    The salivary gland transcriptome analysis of Lutzomyia ayacuchensis, a vector of cutaneous leishmaniasis in Ecuadorian Andes, was performed and abundant transcripts coding for secreted proteins were identified. The most abundant transcript coded for an RGD-containing peptide was expressed in Escherichia coli and its activity was characterized. The resulting protein inhibited both platelet aggregation and blood coagulation pathway, indicating that the peptide plays an important role in the blood feeding of Lu. ayacuchensis by inhibiting host hemostasis via dual mechanisms. On the other hand, salivary nucleotidases of sand flies were assessed on their activity as an exacerbation factor for Leishmania infection. Salivary nucleotidases, PduApy and PduADA, slightly accelerated the disease progression after co-injection of Leishmania parasites, suggesting that these proteins in saliva may be partly associated with exacerbation of the disease in leishmaniasis.
  • 捕食性昆虫唾液の生物機能利用
    科学技術振興機構:研究成果最適展開支援事業(A-STEP)
    Date (from‐to) : 2010/09 -2011/09 
    Author : 加藤 大智
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
    Date (from‐to) : 2009 -2010 
    Author : KATO Hirotomo
     
    In order to disclose the mechanism of enhancement of Leishmania infection by sand fly saliva, DNA vaccines encoding dominant salivary proteins from Phlebotomus duboscqi were prepared and immune responses induced by these antigens were assessed. As the result, three salivary proteins were found to effectively induce humoral responses in mice. Since humoral immune responses were shown to exacerbate Leishmania infection, these salivary proteins were suggested to associate with the enhancement of the infection via host immunity.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2008 -2010 
    Author : KISO Yasuo, IWATA Hiroyuki, KATO Hirotomo
     
    Under the condition of diabetes or allergy, differentiation of uterine natural killer (uNK) cells was delayed, their apoptosis was inhibited, and placental growth factor (PlGF) was decreased in production. However, the number of mature uNK cells was significantly increased, suggesting that deficiency of PlGF was compensated with PlGF secreted by uNK cells. Under such conditions, expression of vascular endothelial growth factor had no changes, but decidualization was promoted, suggesting that differentiation of uNK cells was induced by insulin-like growth factor and interleukin-15 derived from decidual cells.
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    Date (from‐to) : 2006 -2009 
    Author : HASHIGUCHI Yoshihisa, UEZATO Hiroshi, KATAKURA Ken, MIMORI Tatsuyuki, ITO Makoto, KATO Hirotomo, KORENAGA Massataka, YMMAMOTO Yu-ichi, MANUEL Calvopina
     
    Leishmaniasis is one of the protozoan infectious diseases transmitted by blood-sucking insects, sandflies. The disease is widely distributed, affecting at least 12 million people in 88 countries of the world. In this study, three disease factors, patients, vector sandflies, and reservoir animals, were investigated by employing molecular biological, immunological and epidemiological methods. Main results obtained are as follows : (1) relation between Leishmania spp. and disease forms, (2) determination of vector species, (3) search for different mammals infected with Leishmania, (4) development of rapid diagnosis and treatment, (5) search for control measures at each endemic area.
  • 組換えタンパクを用いた牛のクラミジア科細菌の血清診断法の確立と疫学調査への応用
    財団法人森永奉仕会:
    Date (from‐to) : 2007/04 -2008/03 
    Author : 加藤 大智
  • 吸血昆虫唾液由来の新規生理活性物質の探索
    稲盛財団:
    Date (from‐to) : 2007/04 -2008/03 
    Author : 加藤 大智
  • サシチョウバエ唾液成分を用いたリーシュマニア感染防御ワクチンの候補抗原の探索
    文部科学省:科学研究費補助金(若手研究(B))
    Date (from‐to) : 2006/04 -2008/03 
    Author : 加藤大智
     
    疾患流行地(エクアドル、ペルー、パキスタンなど)において、リーシュマニア症の臨床疫学調査を行い、その伝播に関する調査研究活動を行っている。また、分子生物学的手法を用いた感染原虫種の同定法を確立し、疾患流行地での感染患者の疫学調査へと応用している。さらに、ベクターであるサシチョウバエからの病原体検出・同定法の開発ならびにベクター種同定法の確立を行い、疾患流行地での疫学調査への応用を行っている。
  • Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2007 -2008 
    Author : IWATA Hiroyuki, MAEDA Ken, KATO Hirotomo
     
    難治性ウイルス感染症ならびに腫瘍における急性期糖蛋白変動解明と新規機能発見を目的に, 炎症に伴って上昇する血中糖蛋白(α1 酸性糖蛋白)を, ウシ血清およびネコ腹水から精製分離し, 各種疾患における変動, 糖鎖を解析し, 特にウシ白血病での血中上昇と糖鎖変動, ネココロナウイルス感染症(伝染性腹膜炎)での血中上昇がみられた.また, 実験動物の肝臓から本蛋白遺伝子のmRNA検出が可能となり, 基礎研究への応用が期待される.
  • サシチョウバエ唾液成分を用いたリーシュマニア感染防御ワクチンの候補抗原の探索
    日本学術振興会:科学研究費助成事業 若手研究(B)
    Date (from‐to) : 2006 -2007 
    Author : 加藤 大智
     
    本研究は、ベクターであるサシチョウバエの唾液タンパクをリーシュマニア感染防御ワクチンとして応用するという新たな発想でのワクチン開発研究を行うことを目的とする。 これまでの研究で、L.major「を媒介するサシチョウバエ P.duhoscqiの唾液タンパクのプロテオーム解析およびトランスクリプトーム解析を行い、唾液の主要構成タンパクを明らかにしてきた。 この解析結果をもとに10種類程度の主要タンパクと、それらのうち抗原性にバリエーションがみられたものの、合計20種類程度の唾液タンパクをコードする遺伝子を哺乳類細胞タンパク発現ベクターに組込み、DNAワクチンを作製した。マウスの右耳をDNAワクチンで1週間おきに3回免疫し、最終免疫の1週間後、左耳に唾液腺抽出物をチャレンジ、細胞性免疫応答の指標であるDTHを測定した。また、液性免疫応答の指標として、唾液タンパクに対するIgG抗体応答を検討した。 マウスに誘導される免疫応答を23種類の唾液タンパクについて検討した結果、それぞれの抗原の免疫原性に強弱が認められた。このうち、主要唾液成分でもある15, 32,42および44 kDaの唾液タンパクの免疫原性が高く、32 kDaのタンパクは液性免疫応答、42 kDaのタンパクは細胞性免疫応答、15 kDaおよび44 kDaのタンパクは両方の免疫応答を強く誘導することが明らかとなった。サシチョウバエ唾液成分に対する細胞性免疫応答がリーシュマニア感染防御効果をもたらすと考えられることから、15,42および44 kDaの唾液タンパクがワクチン候補抗原として考えられた。本研究で得られた結果は、ベクター唾液成分を用いた新たなワクチン開発に有用な知見をもたらすもので、今後は本成果をもとに、感染動物実験によりこのワクチンの有効性を検証していく必要があると考えられた。
  • 人獣共通感染症制圧に関する萌芽的教育研究
    文部科学省:海外先進教育研究実践支援プログラム
    Date (from‐to) : 2004/02 -2005/01 
    Author : 加藤 大智
  • Pathophysiological studies on the New and Old World leishmaniases and their transmission
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    Date (from‐to) : 2002 -2005 
    Author : HASHIGUCHI Yoshihisa, NONAKA Shigeo, UEZATO Hiroshi, KATAKURA Ken, MIMORI Tatsuyuki, CALVOPINA Manuel
     
    The following findings on the pathobiology and transmission on the New and Old World leishmaniases were obtained from Ecuador, Argentina and Pakistan, in addition to the results of different experimental studies. 1.Parasitological findings : RNA editing regions of Cytochrome b (Cyt b) gene of 13 human pathogenic Leishmania species (14 strains) were analyzed. The regions were compared with those of non-human pathogenic Leishmania parasite, L. tarentolae (Sauroleishmania). 2.Vector entomological findings : A molecular technique sensitive enough to detect Leishmania organisms within each sandfly was established. The Leishmania parasites found in the flies were identified successfully by assessing Cyt b gene sequences. In northern Argentina, 3 species of the genus Lutzomyia, Lu. neivai, Lu. cortelezzii, and Lu. sallesi were found ; no natural infection of the flies with Leishmania was observed. In Pakistan, the materials collected were examined microscopically and molecular-biologically on their morphology and Leishmania parasite infection. No parasite was detected by PCR. In Pakistan, the flies collected were identified as Phlebotomus papatasi, Sergentomyia christophersi and S. punjubensis based on their morphology. 3.Diagnosis and parasite detection : By PCR-based methods, 6 out of 61 dogs were found to be positive for Leishmania minicircle kinetoplast DNA by semi-nested PCR and southern hybridization. 4.Clinical and epidemiological aspects : In Ecuador, the frequency distribution of different disease forms was calculated as follows : CL, 91.2% and MCL, 8.9%, and only one each of DL and DCL was found, but no VL was observed. In Pakistan, our study suggested that the disease is spreading gradually from the endemic areas to the virgin areas. 5.Experimental leishmaniasis : Experimental results suggested that ONO-4007 and INF-γ are the potent stimulators for activation of macrophages by inducing iNOS expression in Leishmania-infected macrophages (J774), which render the leishmanicidal activity against intracellular amastigotes proliferation.
  • 牛のヘルパーTリンパ球サブセット解析による免疫学的防御能の評価法の確立
    財団法人森永奉仕会:
    Date (from‐to) : 2002/04 -2003/03 
    Author : 加藤 大智
  • Analysis and application of molecular dynamics in induction of implantation
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2002 -2003 
    Author : IWATA Hiroyuki, OKUDA Masaru, KATO Hirotomo, KISO Yasuo
     
    The molecule, which is available for embryonic implantation in mice, has not been discovered without the leukemia inhibitory factor (LIF). So, the molecular dynamics in the implantation was analysed by microarray technology using the LIF KO and the delayed implantation mice. The microarray analysis in this study used MG_U74Av2 array (Affymetrix Co.), which detected the 12,489 genes. We detected the repression of gene expression in 50 genes 4 days after pregnancy in the LIF KO and delayed implantation mice. Next, mice with delayed implantation were produced, and a role of LIF at the implantation period was clarified to be essential for the event. About 80% of the selected 50 genes could be controlled by only LIF. As for LIF treatment, the effects of LIF were arisen in various times from several minutes to 6 hours after increase of LIF in the blood. Furthermore, expression and functional analyses of CD9 revealed that CD9 was increased in gene and protein levels at the implantation period and the inhibition of implantation was observe in CD9 KO mice transplanted with fertilized eggs. As fox gene transfer technology using Lentivirus vector, AP and ZAP genes were introduced in mice and the expressions of these genes were confirmed
  • HTLV-I感染動物実験系を用いた免疫寛容の解析
    日本学術振興会:科学研究費助成事業 特別研究員奨励費
    Date (from‐to) : 1999 -2000 
    Author : 加藤 大智
  • 馬のサイトカインに関する研究
    日本学術振興会:科学研究費助成事業 特別研究員奨励費
    Date (from‐to) : 1998 -1998 
    Author : 加藤 大智

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  • 2020/09 - Today   Japanese Society of Veterinary Parasitologists   Administrator
  • 2020/08 - Today   Acta Tropica   Editorial Board
  • 2010/11 -2020/08   Journal of Bacteriology & Parasitology   Editorial Board


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