人脐带间充质干细胞抑制T细胞免疫作用

Human umbilical cord mesenchymal stem cells inhibit T cell immunity

目的研究人脐带间充质干细胞(hUC-MSCs)在体外对淋巴细胞增殖和免疫调控功能的影响。方法采用组织块贴壁法分离健康捐献者来源的脐带进行分离培养。培养至第3~5代时,进行多向分化和细胞表型鉴定。获取健康供者外周血单个核细胞,并通过CD3免疫磁珠分选出T淋巴细胞,进行荧光染料CFSE标记,然后分成单独培养组(T细胞)和共培养组(按T∶MSC=5∶1的比例共培养),两组均采用CD3/CD28单克隆抗体活化,培养3 d后通过流式细胞术检测T淋巴细胞的增殖情况,并检测Th1/Th17细胞亚群的变化以及对Treg细胞亚群的影响。结果健康捐献者来源的hUC-MSCs高表达CD29、CD44、CD73、CD90、CD105、CD166、HLA-DR,不表达CD31、CD34、CD45,并具有多向分化潜能。与单独培养组比较,共培养组中的T淋巴细胞增殖率和Th1、Th17细胞亚群比例明显降低,Treg细胞比例明显升高。结论hUC-MSCs通过抑制T淋巴细胞的增殖、下调Th1/Th17和上调Treg细胞参与免疫调节,发挥免疫抑制作用。

Objective To investigate the effects of human umbilical cord mesenchymal stem cell(hUC-MSCs)on lymphocyte proliferation and immunoregulation in vitro.Methods The umbilical cord from healthy donors was isolated and cultured by the method of tissue explant attachment.Multidirectional differentiation and phenotypic identification were carried out at the 5th passage.Periph-eral blood mononuclear cells were obtained from healthy donors,T lymphocyte were isolated by CD3 immunomagnetic beads,and labeled with fluorescent dye CFSE,and then divided into single culture group(T cell)and co-culture group(co-culture according to the ratio of T:MSC=5:1),both groups were activated with CD3/CD28 monoclonal antibodies.After 3 days,T cell proliferation and Th1/Th17 subsets were examined by Flow cytometry.Results hUC-MSCs from healthy donors expressed high levels of CD29,CD44,CD73,CD90,CD105,CD166 and HLA-DR,but not expressed CD31,CD34 and CD45,and had multidirectional differentiation poten-tial.Compared with the single culture group,the T cell proliferation rate and the percentage of TH1 and TH17 subsets were significantly lower,and the percentage of Treg was significantly higher,in the co-culture group.Conclusion hUC-MSC plays an immunosuppres-sive role by inhibiting T-cell proliferation,down-regulating Th1/Th17 subsets and up-regulating Treg cells.