骨髓间充质干细胞体外诱导免疫调节机制的探讨

摘要

目的:观察骨髓间充质干细胞(BM MSCs)对体外活化T细胞的免疫调节作用.方法:提取Wistar大鼠BM MSCs及新鲜脾淋巴细胞做共培养.实验分3组,3个时间点:分别为0、24、48 h脾淋巴细胞/BM MSCs+刀豆蛋白A(ConA)(实验组),脾淋巴细胞+ConA(对照组),单纯淋巴细胞组(空白组).MTT检测T淋巴细胞活性,ELISA检测细胞因子TNF-α、IL-10及TGF-β水平,流式检测Foxp3+调节性T细胞表达率.结果:(1)与对照组相比,实验组24、48 h在2个时间点T淋巴细胞活性均显著降低(P＜0.05)；(2)与对照组相比,实验组TNF-α在2个时间点有显著降低(P＜0.05),实验组IL-10、TGF-β表达水平有显著升高(P＜0.05)；(3)实验组Foxp3+T调节细胞表达率高于对照组；(4)随着时间延长,空白组及对照组T淋巴细胞活性均显著降低(P＜0.05),实验组T淋巴细胞活性随时间延长差异无统计学意义.结论:BM MSCs可以抑制T淋巴细胞活化,并通过减少炎症因子TNF-α的释放抑制免疫应答.另外,BM MSCs可通过自分泌及诱导T调节细胞产生并分泌免疫抑制因子IL-10、TGF-β下调免疫反应,产生免疫耐受.%Objective: To investigate the immunoregulation mechanism of allogeneic bone mesenchymal stem cells(BM MSCs) on T lymphocyte cell proliferation. Methods: Several BM MSCs and T lymphocyte cell from Wistar rats were cocultured. There were 3 groups, comprising splenic lymphocyte/BM MSCs+ConA (experimental group), splenic lymphocyte+ConA (control group ), splenic lymphocyte (blank). Detect the viability of T lymphocyte by MTT, detect the level of cell factor TNF-α, IL-10 and TGF-β by ELISA, and detect the expression percentage of Foxp3+ regulatory T cells by flow cytometry. Results: (1)T lymphocyte cell proliferation were significantly lower in experimental group compared with control group (P<0.05). (2)TNF-α were significantly lower in experimental group compared with control group(P<0.05). IL-10, TGF-β were significantly greater in experimental group compared with control group(P<0.05). (3)The level of regulatory T cell in experimental group were significantly greater compared with control group (P<0.05). (4 )With the extent of time, the level of T lymphocyte cells were significantly decreased. Conclusion: T lymphocyte cell proliferation are significantly lower in experimental group compared with control group, so is the level of TNF-α.But BM MSCs can secrete IL-10 and TGF-β and boost the level of regulatory T cell to promote immune tolerance.