摘要 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9 d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。

Abstract Objective: To investigate effects of rhIL-17 on growth and development of mouse bone marrow progenitors and human cord blood CD34+ 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 CD1ahigh, B7-2high,and HLA-DRlow. 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 CD1a+ 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.

* 本课题受国家自然科学基金重点项目(39730420)和国家杰出青年科学基金（39825123)资助