Hiraoka A, Sugimura A, Seki T, Nagasawa T, Ohta N, Shimonishi M, Hagiya M, Shimizu S
Department of Internal Medicine, Osaka Dental University, 1-5-17 Ohtemae, Chuo-ku, Osaka 540, Japan.
Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7577-82. doi: 10.1073/pnas.94.14.7577.
Multiple growth factors synergistically stimulate proliferation of primitive hematopoietic progenitor cells. A human myeloid cell line, KPB-M15, constitutively produces a novel hematopoietic cytokine, termed stem cell growth factor (SCGF), possessing species-specific proliferative activities. Here we report the molecular cloning, expression, and characterization of a cDNA encoding human SCGF using a newly developed lambdaSHDM vector that is more efficient for differential and expression cloning. cDNA for SCGF encodes a 29-kDa polypeptide without N-linked glycosylation. SCGF transiently produced by COS-1 cells supports growth of hematopoietic progenitor cells through a short-term liquid culture of bone marrow cells and exhibits promoting activities on erythroid and granulocyte/macrophage progenitor cells in primary semisolid culture with erythropoietin and granulocyte/macrophage colony-stimulating factor, respectively. Expression of SCGF mRNA is restricted to myeloid cells and fibroblasts, suggesting that SCGF is a growth factor functioning within the hematopoietic microenvironment. SCGF could disclose some human-specific mechanisms as yet unidentified from studies on the murine hematopoietic system.
多种生长因子协同刺激原始造血祖细胞的增殖。一种人髓细胞系KPB - M15持续产生一种新型造血细胞因子，称为干细胞生长因子（SCGF），它具有种属特异性增殖活性。在此，我们报告了使用一种新开发的λSHDM载体对编码人SCGF的cDNA进行分子克隆、表达及特性分析，该载体在差异和表达克隆方面更高效。SCGF的cDNA编码一种29 kDa的无N - 连接糖基化的多肽。COS - 1细胞瞬时产生的SCGF通过骨髓细胞的短期液体培养支持造血祖细胞的生长，并且在分别与促红细胞生成素和粒细胞/巨噬细胞集落刺激因子的原代半固体培养中，对红系和粒细胞/巨噬细胞祖细胞表现出促进活性。SCGF mRNA的表达局限于髓细胞和成纤维细胞，这表明SCGF是一种在造血微环境中发挥作用的生长因子。SCGF可能揭示一些尚未从小鼠造血系统研究中明确的人类特异性机制。
