胎儿脐带血间充质干细胞对γδT淋巴细胞功能的影响及其机制

Effects of fetal umbilical cord blood mesenchymal stem cells on γδT lymphocyte function and its related mechanism

目的探讨胎儿脐带血间充质干细胞对γδT淋巴细胞功能的影响及相关分子机制。方法人外周血单核细胞（PBMCs）或γδ T细胞在胎儿脐带血间充质干细胞（UC-MSCs）存在或不存在的条件下经2 μg/ml聚丙烯酰胺（PAM）和100 IU/ml白细胞介素-2（IL-2）活化后，流式细胞术检测PBMCs或γδ T细胞以不同比例与UC-MSCs共培养时对γδ T细胞增殖、细胞因子干扰素-γ（IFN-γ）、肿瘤坏死因子-α（TNF-α）和白细胞介素-10（IL-10）表达和细胞毒性作用；流式细胞术检测UC-MSCs对γδ T细胞Fas-L和TRAIL表达的影响及γδ T细胞凋亡的影响。结果γδ T细胞以不同比例与UC-MSCs共培养时，UC-MSCs以剂量依赖性抑制γδ T细胞增殖；PBMCs和UC-MSCs以3∶1及40∶1比例培养时，IFN-γ＋细胞比例分别下降了为3∶1和40∶1（P=0.001、0.021），颗粒酶B阳性细胞比例分别升高了79.7%、165.0%，与UC-MSCs共培养对TNF-α＋、IL-10＋ γδ T细胞比例没有显著影响（P=0.062）；细胞毒性作用检测结果表明，UC-MSCs抑制γδ T细胞对H1N1[H1N1具血球凝集素（Hemagglutinin）第1型、神经氨酸酶（Neuraminidase）第1型的病毒]感染的A549细胞的毒性作用，且PBMCs和UC-MSCs以3∶1及40∶1比例培养时，Fas-L＋γδ T细胞比例降低了87.6%、37.5%（P=0.000、0.009），TRIAL＋ γδ T细胞比例降低了43.2%、18.7%（P=0.037、0.042），但UC-MSCs不影响γδ T细胞凋亡（P=0.070、0.064）。结论UC-MSCs能抑制增殖和细胞凋亡并调控其细胞因子表达，Fas-L和TRIAL与上述调控效应有关。

ObjectiveTo explore the effects of fetal umbilical cord blood mesenchymal stem cells on γδT lymphocyte function and its related mechanism.MethodsThe Human peripheral blood mononuclear cells （PBMCs） or γδT cells were activated and expanded with 2 μg/ml pamidronate and 100 IU/ml interleukin-2 （IL-2） with or without the presence Fetal umbilical cord blood mesenchymal stem cells （UCMSCs）. Flow cytometry was performed to evaluate the effects of UC-MSCs on proliferation, cytokine expression and cytotoxicity of γδT cells; besides, flow cytometry was used to detect the effects of UC-MSCs on Fas-L and TRAIL expression in γδT cells and γδT cell apoptosis as well.ResultsUC-MSCs inhibited γδT cell proliferation in a dose-dependent but cell-contact independent manner; when PBMCs and UC-MSCs were cultured at a ratio of 3∶1 and 40∶1, IFN-γ＋ cells decreased by 46.7% and 31.4%, respectively （P=0.001, P=0.021）, granzyme B positive cells increased by 79.7%, 165%, respectively, while the ratio of TNF-α and IL-10 positive cells did not change significantly compared with the control group （P=0.062）; Cytotoxicity test results showed that, UCMSCs inhibited the cytotoxicity ofγδT cells against influenza virus H1N1 infected A549 cells, and when PBMCs and UC-MSCs were cultured at a ratio of 3∶1 and 40∶1, Fas-L＋ γδT cells decreased by 87.6% and 37.5% （P=0.000, 0.009）, the proportion of TRIAL＋ γδT cells decreased by 43.2% and 18.7% （P=0.037, 0.042）, however, UC-MSCs did not affect γδ T cell apoptosis （P=0.070, 0.064）.ConclusionUC-MSCs can suppress γδT cells proliferation and cytotoxicity and modulated their cytokine production, and Fas-L and TRAIL were involved in the regulation.