rhIL-17对小鼠造血前体细胞和人脐血CD34^+干细胞分化发育的影响

Effects of rhIL-17 on Differentiation and Development of Murine Hematopoietic Progenitors and Human Cord Blood CD34+ Stem Cells

目的:探讨重组人白细胞介素-17(Interleukin-17,IL-17)对小鼠骨髓造血前体细胞和人脐血来源的CD34^+干细胞生长发育的影响.方法:采用常规方法采集小鼠造血前体细胞;采用Mini-MACS分离技术,从正常人脐血分离人CD34^+干细胞.体外加入IL-17和/或GM-CSF、IL-4培养分离的前体细胞,应用流式细胞仪检测其表型,采用ELISA法检测了其分泌的IL-12水平,通过[~3H]-TdR掺入法测定其刺激同种异体T淋巴细胞增殖的能力.结果:IL-17促进了小鼠骨髓来源的未成熟DC表达Ia,B7-2等免疫分子,促使其分泌较高水平的IL-12,该细胞也能刺激同种异体T细胞有效增殖,表现出了成熟DC的特征.IL-17单独培养9d促使人脐血CD34^+干细胞扩增了2倍,部分细胞高表达CD1a及B7-2,低表达HLA-DR,未检测到CD83的表达.该细胞能促使同种异体T细胞增殖,但作用较弱;而rhIL-17与GM-CSF联合培养后扩增了14倍,培养细胞中CD1a、B7-2阳性细胞的比例明显升高,且此细胞刺激同种异体T细胞增殖的能力较强.结论:IL-17体外可促进小鼠骨髓造血前体细胞来源的DC成熟;与GM-CSF联合培养既能促进CD34^+干细胞增殖,又能使之获得DC特征,初步提示IL-17与GM-CSF联合作用可促进CD34^+干细胞向DC分化.

To investigate effects of rhIL-17 on growth and development of mouse bone marrow progenitors andhuman cord blood LD34^+ stem cells. Methods: Mouse bone marrow progenitors were isolated by routine protocol, and CD34^+ stem cells were isolated from normal human cord blood by Mini-MACS, then cultured with rhIL-17 and/or GM-CSF/IL-4. The phenotypes of the cells were analyzed by FACS, IL-12 level was analyzed by ELISA and T cell stimulating activity in allo-MLR was determined by [~3H]-TdR incorporation. Results: Expression of MHC class II molecules and B7-2 on the surface of immature DC derived from mouse bone marrow progenitors was up-regulated by IL-17. The capacity of the cells to secrete IL-12 and their T cell stimulating activity were also enhanced. The cells showed the characteristics of mature DC. After cultured with IL-17 for 9 days, the number of CD34^+ stem cells increased by 2 times. The phenotypes of some cells were CDla^(high), B7-2^(high), and HLA-DR^(lwo). The cells could stimulate allo geneic T cells to proliferate but their capacity was lower than that of the cells cultured with IL-17 combined with GM-CSF. The cells cultured with IL-17 and GM-CSF proliferated markedly and the rate of CDla^+ and B7-2^+ cells increased significantly. The T cell stimulating activity of cells was also augmented. Conclusion: IL-17 could promote DC derived from mouse bone marrow progenitors to mature. When combined with GM-CSF, IL-17 could induce human CD34^+ stem cells not only to proliferate markedly but also to show characteristics of DC, indicating that CD34^+ stem cells might differentiate to DC by IL-17.