骨髓间充质干细胞抑制再生障碍性贫血患者外周血T细胞增殖的实验研究

Experimental study on bone marrow mesenchymal stem cells inhibiting T lymphocytes proliferation in patients with aplastic anemia

背景:既往研究发现骨髓间充质干细胞具有免疫抑制作用,而再生障碍性贫血患者存在T淋巴细胞异常活化及增殖。目的:体外分析骨髓间充质干细胞对再生障碍性贫血患者外周血T淋巴细胞增殖的抑制作用。方法:分离再生障碍性贫血患者外周血T淋巴细胞,行羧基荧光素乙酰乙酸琥珀酰亚胺酯(CFDASE)荧光染色,与体外培养扩增的骨髓间充质干细胞按3︰1比例直接接触法及Transwell法共培养,加入植物血凝素(PHA)刺激T淋巴细胞增殖,并设阴性及阳性对照。流式细胞术检测各组T细胞增殖情况,评价骨髓间充质干细胞对T淋巴细胞增殖的影响。结果与结论:CFDASE染色分析显示,直接接触组T细胞增殖较阳性对照组明显减低(P<0.01);Transwell组T细胞增殖亦较阳性对照组减低(P<0.05);直接接触组T细胞增殖较Transwell组明显减低(P<0.01)。骨髓间充质干细胞可能通过直接接触及分泌某些细胞因子方式抑制再生障碍性贫血患者异常增殖的T细胞,以直接接触方式发挥主要作用。

BACKGROUND：Previous studies have found bone marrow mesenchymal stem cells（BMSCs） have immunosuppressive effects.T lymphocytes in patients with aplastic anemia（AA） are abnormal activatory and proliferous.OBJECTIVE：To study the inhibitory effects of BMSCs on T lymphocyte proliferation in vitro in AA patients.METHODS：T lymphocytes were isolated from the peripheral blood of patients with AA and stained with carboxyfluorescein diacetate succinimidyl ester（CFDA SE）,and then co-cultured with BMSCs at 1：3 ratio using closing-contact and Transwell methods.Phytohemagglutinin was added to stimulate T lymphocytes proliferation.Besides,negative and positive controls were set.RESULTS AND CONCLUSION：Flow cytometry was used to detect the T cell proliferation.CFDA SE staining analysis showed that T lymphocyte proliferation in closing-contact group was much lower than positive control（P〈0.01）.T lymphocyte proliferation in Transwell group was lower than positive control（P〈0.05）.Besides,T lymphocyte proliferation in closing-contact group was much lower than Transwell group（P〈0.01）.BMSCs can inhibit abnormal proliferation of T cells in patients with AA possibly through closing contact and secreting some cytokines,which makes it possible to correct the immune abnormalities in AA.Furthermore,the closing-contact mechanism may play a major role in inhibiting T cell proliferation.