人乳牙牙髓干细胞对干燥综合征患者CD4+T细胞的免疫抑制效应

Immunosuppressive effect of stem cells from human exfoliated deciduous teeth on CD4+T cells in patients with Sjögren's syndrome

关键词:  干燥综合征  人乳牙牙髓干细胞  CD4⁺T细胞  IL-6抗体

Key words:  Sjögren's syndrome  stem cells from human exfoliated deciduous teeth  CD4⁺T cells  IL-6 antibody

摘要:

目的 探讨在体外人乳牙牙髓干细胞(stem cells from human exfoliated deciduous teeth, SHED)及其联合IL-6抗体对干燥综合征(Sjögren's syndrome, SS)外周血活化的CD4⁺T细胞的免疫抑制效应。方法 培养并鉴定SHED；流式细胞术检测健康者和SS患者外周血CD4⁺T细胞中Th1、Th2、Th17、Treg及Tfh的比例；将健康者和SS患者PBMC各自单独培养或与SHED共培养,ELISA法检测培养上清液中IL-6浓度,在各组中添加或不添加IL-6抗体,72h后流式细胞术检测CD4⁺T细胞增殖情况。结果 SS患者外周血CD4⁺T细胞中Th17及Tfh比例较健康者升高(P<0.05)；健康者与SS患者共培养组的Th17比例显著降低(P<0.001),SS患者共培养组的Treg比例有所升高(P<0.05)；在SS患者共培养组中添加IL-6抗体,可显著降低CD4⁺T细胞中Th2的比例(P<0.05)。结论 SHED可抑制SS患者CD4⁺T细胞的增殖,降低SS患者CD4⁺T细胞中Th17的比例且增加Treg的比例；IL-6抗体可降低与SHED共培养的SS患者PBMC中CD4⁺T细胞Th2亚型比例。

Abstract:

Objective To investigate the immunosuppressive effect of stem cells from human exfoliated deciduous teeth (SHED) and SHED combined with IL-6 antibody on peripheral blood activated CD4⁺T cells of patients with Sjögren's syndrome (SS) in vitro. Methods The stem cells from the dental pulp of deciduous teeth were identified by flow cytometry. The percentage of Th1, Th2, Th17, Treg and Tfh in peripheral blood CD4⁺T cells of healthy donors and patients with SS were detected by flow cytometry. Peripheral blood mononucleocytes (PBMCs) of healthy donors and patients with SS were cultivated or co-cultured with SHED, the concentrations of IL-6 in culture supernatant were detected by ELISA. The CD4⁺T cells proliferation was tested by flow cytometry 72h after cultured with or without IL-6 antibody. Results The percentage of Th17 and Tfh in CD4⁺T cells of SS patients were increased compared to healthy donors(P<0.05). The percentage of Th17 was significantly reduced in SHED and PBMC co-culture system both in healthy and SS groups(P<0.001), in addition, the percentage of Treg was increased in SS group(P<0.05). IL-6 level was higher in PBMC and SHED co-culture supernatant than in PBMC culture supernatant both in healthy donors or SS patients. In SS patients PBMC and SHED co-culture system, adding IL-6 antibody significantly reduced the percentage of Th2 in CD4⁺T cells(P<0.05). Conclusion SHED can inhibit the proliferation of CD4⁺T cells, decrease the percentage of Th17 and increase the amount of Treg in SS patients.IL-6 antibody can reduce the percentage of Th2 in PBMC co-cultured with SHED of SS patients.