脐血多能干细胞对阿尔茨海默病患者外周血淋巴细胞的免疫调节作用

Immune-modulation of cord blood-derived multipotent stem cells on lymphocytes of patients with Alzheimer's disease

目的研究脐血多能干细胞(CB-SCs)对阿尔茨海默病(AD)患者外周血淋巴细胞(LCs)的调节作用,初步探讨其治疗AD的潜能。方法人脐血中分离并培养CB-SCs;AD患者外周血中分离淋巴细胞;将两者共培养3 d,其中植物凝集素P(PHA-P)刺激组刺激淋巴细胞增殖;ELISA法检测上清液中IL-1、IL-4和IL-10的含量,流式细胞仪检测淋巴细胞亚群中CD4+/CD8+T细胞的比例、CD4+T细胞中调节性T细胞的比例及Treg细胞功能蛋白IL-10和TGF-β1的阳性率。结果 1)CB-SCs能抑制PHA-P诱导的LCs增殖及LCs聚集;2)CB-SCs共培养组的促炎因子IL-1明显下降(P<0.05),抗炎因子IL-4和IL-10明显上升(P<0.01);3)CB-SCs可下调CD4+/CD8+T淋巴细胞比例(P<0.01);4)在无PHA-P作用时CB-SCs可以增加CD4+T淋巴细胞中Treg细胞的比例(P<0.01),PHA-P存在时CB-SCs主要增强Treg细胞功能蛋白的表达。结论 CB-SCs在体外对AD患者外周血的淋巴细胞具有免疫调节作用,主要通过增加Treg细胞的比例及增强其抗炎功能来发挥作用。

Objective To investigate the regulatory effect of cord blood derived-multipotent stem cells（ CB-SCs）on peripheral blood lymphocytes（ LCs） of patients with Alzheimer＇s disease（ AD） and to explore the therapeutic potential of CB-SCs for AD. Methods CB-SCs were isolated from human cord blood. Lymphocytes were isolated from the peripheral blood of patients with AD. Then,after the two cell populations co-cultured with or without phytohaemagglutinin-P（ PHA-P） for 3 days,the levels of cytokines in the supernatant were detected with the ELISA test,the proportions of T-cell subsets were determined by the flow cytometric analysis. Results 1） CB-SCs showed an inhibitory effect on lymphocyte proliferation and gathers induced by the PHA-P; 2） Compared with the control group,the level of the pro-inflammatory factor IL-1 was dramatically decreased（ P〈0. 05）,while the release of the anti-inflammatory factors IL-4 and IL-10 were significantly increased（ P〈0. 01） in the CB-SCs co-culturedgroup. 3） The ratio of CD4^＋/ CD8^＋T cells in the CB-SCs co-cultured group was significantly lower than that in the control group（ P〈0. 01）. 4） Compared with the control group,the proportion of regulatory T cells（ Tregs） in the CD4^＋T cells was higher in the CB-SCs co-cultured group without the stimulation of PHA-P（ P〈0. 01）,while the anti-inflammatory proteins expressed in the Tregs was at a higher level with the stimulation of PHA-P. Conclusions CB-SCs can regulate lymphocytes of patients with Alzheimer＇s disease in vitro,which is mainly displayed with the increased proportion of Tregs subset and enhanced anti-inflammatoty function of Tregs.