小澤 敬也

G-CSF (granulocyte colony-stimulating factor) is known to specifically stimulate the production and the functional activation of neutrophils. To investigate the intracellular signaling pathway of myeloid cells stimulated by G-CSF, we isolated new genes whose expression was induced by G-CSF. First of all, we constructed αgt10 cDNA library from G-CSF-stimulated mononuclear cells (MNC) of a chronic myelogeneous leukemia (CML) patient (CML-MNC) and screened the cDNA library by a differential hybridization method. The 24 candidate clones which specifically hybridized with G-CSF-stimulated CML-MNC cDNA probes, but not with unstimulated CML-MNC cDNA probes, were obtained after 8×104 individual clones had been screened. One of these clones, GIG-1 (G-CSF-induced gene-1), was further characterized. The size of the GIG-1 mRNA was about 0.9kb. The GIG-1 mRNA was expressed mainly in the myeloid leukemic cell lines. © 1994 Academic Press, Inc.

G-CSF (granulocyte colony-stimulating factor) is known to specifically stimulate the production and the functional activation of neutrophils. To investigate the intracellular signaling pathway of myeloid cells stimulated by G-CSF, we isolated new genes whose expression was induced by G-CSF. First of all, we constructed αgt10 cDNA library from G-CSF-stimulated mononuclear cells (MNC) of a chronic myelogeneous leukemia (CML) patient (CML-MNC) and screened the cDNA library by a differential hybridization method. The 24 candidate clones which specifically hybridized with G-CSF-stimulated CML-MNC cDNA probes, but not with unstimulated CML-MNC cDNA probes, were obtained after 8×104 individual clones had been screened. One of these clones, GIG-1 (G-CSF-induced gene-1), was further characterized. The size of the GIG-1 mRNA was about 0.9kb. The GIG-1 mRNA was expressed mainly in the myeloid leukemic cell lines. © 1994 Academic Press, Inc.

Stromal cells are known to produce granulocyte colony-stimulating factor (G-CSF) and interleukin 6 (IL-6). To assess the function of bone marrow Stromal cells in the pathological state, we studied their in vitro ability to produce G-CSF and IL-6 in 9 patients with aplastic anemia and 5 normal volunteers, using an enzyme immunoassay method. Constitutive production of IL-6, but not G-CSF, was detected in almost all cases. Interestingly, the inducible production of G-CSF and IL-6 by stromal cells after stimulation with Interleukin-1 and/or lipopolysaccharides was severely depressed in 3 patients with aplastic anemia. Our results may reflect poor hematopoietic activity in the bone marrow in some cases of aplastic anemia. © 1993, Tohoku University Medical Press. All rights reserved.

Stromal cells are known to produce granulocyte colony-stimulating factor (G-CSF) and interleukin 6 (IL-6). To assess the function of bone marrow Stromal cells in the pathological state, we studied their in vitro ability to produce G-CSF and IL-6 in 9 patients with aplastic anemia and 5 normal volunteers, using an enzyme immunoassay method. Constitutive production of IL-6, but not G-CSF, was detected in almost all cases. Interestingly, the inducible production of G-CSF and IL-6 by stromal cells after stimulation with Interleukin-1 and/or lipopolysaccharides was severely depressed in 3 patients with aplastic anemia. Our results may reflect poor hematopoietic activity in the bone marrow in some cases of aplastic anemia. © 1993, Tohoku University Medical Press. All rights reserved.

We constructed a series of murine stem cell factor (mSCF) cDNAs which were sequentially truncated at the 3′ termini. The resultant six mutant cDNA encode N-terminal 183, 179, 162, 149, 142 and 133 amino acid residues of the mature mSCF protein fused to the heterogeneous C-terminal peptides derived from the linker sequences. Each mutant cDNA was transiently expressed in COS cells, and the cultured supernatant was assayed for its ability to support the growth of a human factor-dependent cell line, TF-1 and to enhance colony formation by murine hematopoietic progenitor cells . The results showed that as few as N-terminal 142 but not 133 amino acid residues of mSCF remained biologically active in vitro, suggesting that the region of 9 aminoacids from Asp134 to Ser142 containing aCys138-mediated disulfide bond may contribute to the C-terminal end of the active subdomain of mSCF. © 1992.

We constructed a series of murine stem cell factor (mSCF) cDNAs which were sequentially truncated at the 3′ termini. The resultant six mutant cDNA encode N-terminal 183, 179, 162, 149, 142 and 133 amino acid residues of the mature mSCF protein fused to the heterogeneous C-terminal peptides derived from the linker sequences. Each mutant cDNA was transiently expressed in COS cells, and the cultured supernatant was assayed for its ability to support the growth of a human factor-dependent cell line, TF-1 and to enhance colony formation by murine hematopoietic progenitor cells . The results showed that as few as N-terminal 142 but not 133 amino acid residues of mSCF remained biologically active in vitro, suggesting that the region of 9 aminoacids from Asp134 to Ser142 containing aCys138-mediated disulfide bond may contribute to the C-terminal end of the active subdomain of mSCF. © 1992.

Previous studies demonstrated that human circulating monocytes can proliferate in vitro when incubated with lectin-induced factor(s) from lymphocytes [(1985) Biochem. Biophys. Res. Commun., in press]. This study shows that human monocytes were induced to proliferate when incubated with 1α,25-dihydroxy vitamin D3 (calcitriol) at physiological concentrations. The optimal dose was about 10 nM. Proliferative activity was examined both by measuring the [su3H]thymidine incorporation and by counting cell nuclei. Among other derivatives of vitamin D3, 1α,24 R-dihydroxyvitamin D3 and 1α,24R,25-trihydroxyvitamin D3 stimulated mitotic activity of monocytes. Addition of both calcitriol and lectin-stimulated lymphocyte-conditioned medium to the monocyte culture had an additional effect on the mitotic activity of monocytes. © 1985.