Researchers Database

nagashima shigeo

    InfectionandImmunityVirology Assistant Professor
Last Updated :2021/12/07

Researcher Information


J-Global ID

Research Interests

  • Tsg101   E型肝炎ウイルス   ESCRT機構   放出   MVB経路   粒子形成   分子疫学   B群   消毒済   ロタウイルス   MRSA   生理学   消毒剤   浸淫状況   PVL   新種   プロテオーム   スタフィロコアグラーゼ   黄色ブドウ球菌   成人   熱帯地域   感染培養系   アジア   多剤排出蛋白   下痢症   感染性cDNAクローン   ゲノム変異   下痢   PSAPモチーフ   腸球菌   

Research Areas

  • Life sciences / Virology
  • Life sciences / Hygiene and public health (non-laboratory)
  • Life sciences / Hygiene and public health (laboratory)
  • Life sciences / Hygiene and public health (non-laboratory)
  • Life sciences / Hygiene and public health (laboratory)
  • Life sciences / Healthcare management, medical sociology

Academic & Professional Experience

  • 2013  Jichi Medical UniversitySchool of Medicine講師

Published Papers

  • Hiroshi Okano, Masaharu Takahashi, Yoshiaki Isono, Hiroki Tanaka, Tatsunori Nakano, Yumi Oya, Kazushi Sugimoto, Keiichi Ito, Shigeru Ohmori, Tadashi Maegawa, Makoto Kobayashi, Shigeo Nagashima, Tsutomu Nishizawa, Hiroaki Okamoto
    HEPATOLOGY RESEARCH 44 (10) E63 - E76 1386-6346 2014/10 [Refereed][Not invited]
    Aim: To characterize hepatitis E in Mie prefecture and to investigate whether raw pig liver sold as food in Mie is contaminated with hepatitis E virus (HEV) strains similar to those recovered from patients. Methods: Seventeen patients with sporadic acute hepatitis E treated from 2004 to 2012 were studied. A total of 243 packages of raw pig liver from regional grocery stores were tested for the presence of HEV RNA. The partial genomic sequences of human and swine HEV isolates were determined and subjected to the phylogenetic analyses. Results: The HEV isolates recovered from the 17 patients segregated into genotype 3 (n = 15) and genotype 4 (n = 2), and 15 genotype 3 isolates further segregated into 3e (n = 11) and 3b (n = 4). Pig liver specimens from 12 (4.9%) of the 243 packages had detectable HEV RNA. All 12 swine HEV isolates were grouped into genotype 3 (3a or 3b). Although no 3e strains were isolated from pig liver specimens, two 3b swine strains were 99.5-100% identical to two HEV strains recovered from hepatitis patients, within 412-nt partial sequences. Conclusion: The 3e HEV was prevalent among hepatitis E patients. HEV RNA was detected in approximately 5% of pig liver sold as food. The presence of identical HEV strains between hepatitis patients and pig liver indicated that pigs play an important role as reservoirs for HEV in humans in Mie. Further studies are needed to clarify the source of 3e HEV in the animal and environmental reservoirs.
  • Hiroshi Okano, Tatsunori Nakano, Kazushi Sugimoto, Kazuaki Takahashi, Shigeo Nagashima, Masaharu Takahashi, Masahiro Arai, Hiroaki Okamoto
    HEPATOLOGY RESEARCH 44 (6) 694 - 699 1386-6346 2014/06 [Refereed][Not invited]
    A 67-year-old male living in Tsu city, Mie prefecture, Japan was referred to our hospital for further examination of acute liver injury and was diagnosed as having clinical hepatitis E virus (HEV) infection in January 2010. The HEV strain (HE-JA11-1701) isolated from the patient belonged to genotype 3 and European-type subgenotype 3e. It was presumed that the patient had been infected from a wild boar (Sus scrofa leucomystax) because he consumed meat/viscera from a wild boar that he had captured himself as a hunter approximately 2 months before disease onset. A specimen of the boar meat/viscera that the patient had ingested was not available. However, the HE-JA11-1701 strain was 99.8% identical within the 412-nucleotide sequence of the open reading frame 2 region to a HEV strain (JBOAR012-Mie08) that had been recovered from a wild boar captured near the patient's hunting area in 2008. A phylogenetic analysis confirmed that the two HEV strains had a close genetic relationship and were segregated into subgenotype 3e, supported by a high bootstrap value of 99%. Of note, the HE-JA11-1701 and JBOAR012-Mie08 strains were remotely related to the 3e strains reported in Japan and European countries, with a nucleotide difference of 7.9-13.9%, reinforcing the uniqueness of the 3e strains obtained in the present study. These results strongly support our speculation that the patient developed acute hepatitis E via consumption of HEV-infected boar meat/viscera. Genetic analyses of HEV strains are useful for tracing infectious sources in sporadic cases of acute hepatitis E.
  • Suljid Jirintai, Tanggis, Mulyanto, Joseph Benedictus Suparyatmo, Masaharu Takahashi, Tominari Kobayashi, Shigeo Nagashima, Tsutomu Nishizawa, Hiroaki Okamoto
    VIRUS RESEARCH 185 92 - 102 0168-1702 2014/06 [Refereed][Not invited]
    Although rat hepatitis E virus (HEV) has been identified in wild rats, no cell culture systems for this virus have been established. A recent report suggesting the presence of antibodies against rat HEV in human sera encouraged us to cultivate rat HEV in human cells. When liver homogenates obtained from wild rats (Rattus rattus) in Indonesia were inoculated onto human hepatocarcinoma cells, the rat HEV replicated efficiently in PLC/PRF/5, HuH-7 and HepG2 cells, irrespective of its genetic group (G1-G3). The rat HEV particles released from cultured cells harbored lipid-associated membranes on their surface that were depleted by treatment with detergent and protease, with the buoyant density in sucrose shifting from 1.15-1.16 g/ml to 1.27-1.28 g/ml. A Northern blotting analysis revealed genomic RNA of 7.0 kb and subgenomic RNA of 2.0 kb in the infected cells. The subgenomic RNA of G1-G3 each possessed the extreme 5'-end sequence of GUAGC (nt 4933-4937), downstream of the highly conserved sequence of GAAUAACA (nt 4916-4923). The establishment of culture systems for rat HEV would allow for extended studies of the mechanisms of viral replication and functional roles of HEV proteins. Further investigation is required to clarify the zoonotic potential of rat HEV. (C) 2014 Elsevier B.V. All rights reserved.
  • Shigeo Nagashima, Masaharu Takahashi, Suljid Jirintai, Tanggis, Tominari Kobayashi, Tsutomu Nishizawa, Hiroaki Okamoto
    ARCHIVES OF VIROLOGY 159 (5) 979 - 991 0304-8608 2014/05 [Refereed][Not invited]
    Our previous studies demonstrated that hepatitis E virus (HEV) requires the multivesicular body (MVB) pathway to release virus particles, suggesting that HEV utilizes the cellular ESCRT machinery in the cytoplasm, not at the cell surface, to be released from infected cells. In this study, we generated a murine monoclonal antibody (mAb) against the membrane-associated HEV particles to examine whether the membrane is derived from intracellular vesicles or the cell surface. An established mAb, TA1708, was found to capture the membrane-associated HEV particles, but not the membrane-dissociated particles or fecal HEV, in an immunocapture RT-PCR assay. Furthermore, digitonin treatment confirmed that the membrane on the surface of cell-culture-generated HEV particles was a lipid membrane. Double immunofluorescence staining revealed that mAb TA1708 specifically recognizes trans-Golgi network protein 2 (TGOLN2), an intracellular antigen derived from the trans-Golgi network. Supporting these findings, HEV particles with lipid membranes and ORF3 proteins on their surface were found abundantly in the lysates of HEV-infected cells. These results indicate that HEV forms membrane-associated particles in the cytoplasm, most likely by budding into intracellular vesicles, and that the released HEV particles with a lipid membrane retain the antigenicity of TGOLN2 on their surface.
  • Masaharu Takahashi, Tsutomu Nishizawa, Shigeo Nagashima, Suljid Jirintai, Manri Kawakami, Yoshihide Sonoda, Tadahiro Suzuki, Shogo Yamamoto, Kazuhiro Shigemoto, Kozo Ashida, Yukihiro Sato, Hiroaki Okamoto
    VIRUS RESEARCH 180 59 - 69 0168-1702 2014/02 [Refereed][Not invited]
    Although a consensus classification system for hepatitis E virus (HEV) genotypes is currently unavailable, HEV variants (JBOAR135-Shiz09 and wbJOY_06) from wild boars (Sus scrofa leucomystax) have provisionally been classified into two novel genotypes (5 and 6). While performing a survey of HEV infections among 566 wild boars that were captured in Japan between January 2010 and August 2013, we found 24 boars (4.2%) with ongoing HEV infections: 13 had genotype 3 HEV, 10 had genotype 4 HEV and the remaining boar possessed a novel HEV variant (designated wbJNN_13). The entire wbJNN_13 genome comprised 7247 nucleotides excluding the poly(A) tail, and was highly divergent from known genotype 1 to 4 HEV isolates derived from humans, swine, wild boars, deer, mongoose and rabbits by 22.4-28.2%, JBOAR135-Shiz09 and wbJOY_06 by 19.6-21.9% and rat, ferret, bat and avian HEV isolates by 40.9-46.1% over the entire genome. Phylogenetic trees confirmed that wbJNN_13 is distantly related to all known HEV isolates. A Simplot analysis revealed no significant recombination among the existing HEV strains. These results indicate the presence of at least three genetic lineages of presumably boar-indigenous HEV strains. Further studies to fully understand the extent of the genomic heterogeneity of HEV variants infecting wild boars are warranted. (C) 2013 Elsevier B.V. All rights reserved.
  • Mulyanto, Joseph Benedictus Suparyatmo, I. Gusti Ayu Sri Andayani, Khalid, Masaharu Takahashi, Hiroshi Ohnishi, Suljid Jirintai, Shigeo Nagashima, Tsutomu Nishizawa, Hiroaki Okamoto
    VIRUS RESEARCH 179 102 - 112 0168-1702 2014/01 [Refereed][Not invited]
    Rat hepatitis E virus (HEV) strains have recently been isolated in several areas of Germany, Vietnam, the United States, Indonesia and China. However, genetic information regarding these rat HEV strains is limited. A total of 369 wild rats (Rattus rattus) captured in Central Java (Solo) and on Lombok Island, Indonesia were tested for the presence of rat HEV-specific antibodies and RNA. Overall, 137 rats (37.1%) tested positive for rat anti-HEV antibodies, while 97 (26.3%) had rat HEV RNA detectable on reverse transcription-PCR with primers targeting the ORF1-ORF2 junctional region. The 97 HEV strains recovered from these viremic rats were 76.3-100% identical to each other in an 840-nucleotide sequence and 75.4-88.4% identical to the rat HEV strains reported in Germany and Vietnam. Five representative Indonesian strains, one from each of five phylogenetic clusters, whose entire genomic sequence was determined, were segregated into three genetic groups (a German type, Vietnamese type and novel type), which differed from each other by 19.5-23.5 (22.0 +/- 1.7)% over the entire genome. These results suggest the presence of at least three genetic groups of rat HEV and indicate the circulation of polyphyletic strains of rat HEV belonging to three distinct genetic groups in Indonesia. (C) 2013 Elsevier B.V. All rights reserved.
  • Mulyanto, Sulaiman Ngongu Depamede, Made Sriasih, Masaharu Takahashi, Shigeo Nagashima, Suljid Jirintai, Tsutomu Nishizawa, Hiroaki Okamoto
    ARCHIVES OF VIROLOGY 158 (1) 87 - 96 0304-8608 2013/01 [Refereed][Not invited]
    One hundred sixteen rats (Rattus rattus) captured in Indonesia from 2011 to 2012 were investigated for the prevalence of hepatitis E virus (HEV)-specific antibodies and HEV RNA. Using an ELISA based on HEV genotype 4 with an ad hoc cutoff value of 0.500, 18.1 % of the rats tested positive for anti-HEV IgG. By nested RT-PCR, 14.7 % of the rats had rat HEV RNA, and none were positive for HEV genotype 1-4. A high HEV prevalence among rats was associated with lower sanitary conditions in areas with a high population density. Sixteen of the 17 HEV isolates obtained from infected rats showed > 93.0 % nucleotide sequence identity within the 840-nucleotide ORF1-ORF2 sequence and were most closely related to a Vietnamese strain (85.9-87.9 % identity), while the remaining isolate differed from known rat HEV strains by 18.8-23.3 % and may belong to a novel lineage of rat HEV. These results suggest a wide distribution of rat HEV with divergent genomes.
  • Suljid Jirintai, Jinshan, Tanggis, Dugarjavin Manglai, Mulyanto, Masaharu Takahashi, Shigeo Nagashima, Tominari Kobayashi, Tsutomu Nishizawa, Hiroaki Okamoto
    VIRUS RESEARCH 170 (1-2) 126 - 137 0168-1702 2012/12 [Refereed][Not invited]
    Rabbit hepatitis E virus (HEV) strains have recently been isolated in several areas of China and in the US and France. However, the host range, distribution and zoonotic potential of these HEV strains remain unknown and their propagation in cultured cells has not yet been reported. A total of 211 4-month-old rabbits raised on a farm in Inner Mongolia were tested for the presence of anti-HEV antibodies and HEV RNA. Overall, 121 rabbits (57.3%) tested positive for anti-HEV antibodies, and 151 (71.6%) had detectable HEV RNA. The 174 HEV strains recovered from these viremic rabbits, including two distinct strains each from 23 rabbits, differed from each other by up to 13.6% in a 412-nucleotide (nt) sequence within ORF2, and were 89.3-95.9% identical to the reported rabbit HEV strains in other provinces of China. Three representative Inner Mongolian strains, one each from three phylogenetic clusters, whose entire genomic sequences were determined, shared 79.6-96.7% identities with reported rabbit HEV strains within the entire or 242- to 1349-nt partial genomic sequence. Rabbit HEV strains recovered from liver tissues of rabbits with a high HEV load propagated efficiently in human cell lines (A549 and PLC/PRF/5 cells), suggesting the potential zoonotic risk of rabbit HEV. (c) 2012 Elsevier B.V. All rights reserved.
  • Hideyuki Takahashi, Toshinori Tanaka, Suljid Jirintai, Shigeo Nagashima, Masaharu Takahashi, Tsutomu Nishizawa, Hitoshi Mizuo, Yasuyuki Yazaki, Hiroaki Okamoto
    ARCHIVES OF VIROLOGY 157 (2) 235 - 246 0304-8608 2012/02 [Refereed][Not invited]
    Recent evidence has indicated the cross-species transmission of hepatitis E virus (HEV) from pigs and wild boars to humans, causing zoonosis, mostly via consumption of uncooked or undercooked animal meat/viscera. However, no efficient cell culture system for swine and boar HEV strains has been established. We inoculated A549 cells with 12 swine and boar HEV strains of liver, feces, or serum origin at an HEV load of a parts per thousand yen2.0 x 10(4) copies per well and found that the HEV progeny replicated as efficiently as human HEV strains, with a maximum load of similar to 10(8) copies/ml. However, the HEV load in the culture medium at 30 days post-inoculation differed markedly by inoculum, ranging from 1.0 x 10(2) to 1.1 x 10(7) copies/ml upon inoculation at a lower load of approximately 10(5) copies per well. All progeny were passaged successfully onto A549 and PLC/PRF/5 cells. In sharp contrast, no progeny viruses were detectable in the culture supernatant upon inoculation with 13 swine and boar HEV strains at an HEV load of < 1.8 x 10(4) copies per well. The present study also demonstrates that swine liver sold as food can be infectious, supporting the risk of zoonotic food-borne HEV infection.
  • Mulyanto, Pingki Pancawardani, Sulaiman Ngongu Depamede, Arif Wahyono, Suljid Jirintai, Shigeo Nagashima, Masaharu Takahashi, Tsutomu Nishizawa, Hiroaki Okamoto
    VIRUS RESEARCH 163 (1) 129 - 140 0168-1702 2012/01 [Refereed][Not invited]
    Four novel subgenotypes (C6, C11, C12, and D6) of hepatitis B virus (HBV) were identified in Papua, a multiethnic province of Indonesia. To characterize the HBV strains in Papua, serum samples collected from 515 indigenous inhabitants (mean age: 26.6 +/- 9.6 years) in a previously unexamined area, Nabire, located in northern Papua, were used in the present study. Among 46 samples whose 1.6-kilobase (kb) HBV DNA sequence was amplified, 38 (83%) were typeable into known subgenotypes [B3 (n = 4), Cl (n = 2), C5, (n = 1), C6 (n = 5), C12 (n = 13), and D6 (n = 13)]. An analysis of the full-length sequence of the eight remaining HBV/C isolates whose sequence was either unclassifiable or uncertain within the 1.6-kb sequence showed no significant evidence of recombination in six isolates, and inter-genotypic recombination in two isolates (NAB20 and NAB46). By pairwise comparisons and a maximum-likelihood phylogenetic analysis, six non-recombinant isolates were considered significantly remote from known HBV/C isolates of subgenotypes C1-C12, and were classifiable into four novel subgenotypes (tentatively designated C13-C16). NAB20 and NAB46 were hybrids of C13/B3 and C12/G, respectively, displaying recombination breakpoints in the 5'-terminus of the P gene. Notably, the distribution of presumably indigenous subgenotypes C11-C16 was associated with particular language speakers in Papua. (C) 2011 Elsevier B.V. All rights reserved.


  • Tatsuya Aikawa, Fumio Tsuda, Chisato Ueno, Takashi Mamiya, Hiroaki Sugiyama, Atsuko Soeda, Kazuto Ikezawa, Shigeo Nagashima, Masaharu Takahashi, Hiroaki Okamoto  Acta Hepatologica Japonica  54-  (6)  373  -380  2013  [Not refereed][Not invited]
    We report herewith the transmission of genotype A (A2) hepatitis B virus (HBV) from patients who developed acute hepatitis B to their sexual partners, through interspousal or homosexual infection. The four HBV isolates obtained from two pairs of the index patient and his partner with a secondary infection shared 99.9-100% identities over the entire genome, although each pair of the patients lived in distinct areas, and segregated into a phylogenetic cluster consisting of indigenous HBV/A2 strains isolated in different prefectures in Japan. These results indicate a wide distribution of HBV/A (A2) in Japan that can be transmitted not only from persistently infected patients but also from those with acute HBV infection, and the need for HB vaccination of at-susceptible people to prevent increase in HBV infection in Japan. © 2013 The Japan Society of Hepatology.

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