间充质干细胞在体外实验中对T淋巴细胞的免疫调节作用

发布时间：2018-04-28 05:20

本文选题：细胞因子 + 间充质干细胞(MSC)　；参考：《苏州大学》2006年硕士论文

【摘要】： 目的:通过体外实验研究间充质干细胞(mesenchymal stem cell,MSC)对于不同刺激条件下的T淋巴细胞亚群的免疫调节作用,从而探讨间充质干细胞移植对于移植后的移植物抗宿主病(GVHD)和移植物抗白血病(GVL)的发生所起的作用,旨在寻求间充质干细胞与造血干细胞进行联合移植的优势和潜在应用价值。方法:通过Ficoll-Hypaque梯度密度离心法分离出正常人骨髓单个核细胞,体外培养扩增MSC,获取第3代细胞。将其按照不同的比例加入双向混合淋巴细胞培养(mixed lymphocyte culture, MLC)体系中,分别在第1,3,5天,用MTT比色法检测各组MLC中的T淋巴细胞的增殖情况,再用流式细胞术分析与MSC共孵育体系中或经佛波脂(phorbol myristate acetate,PMA)及离子霉素(Ionomycin)共同刺激下的T淋巴细胞的表面标记以及其内因子IL-4和IFN-γ的分泌变化情况。结果:加入了MSC的MLC体系中,MSC对T淋巴细胞的增殖抑制具有量效关系,且随着共孵育时间延长,抑制程度增强;其中,CD4+T细胞亚群受抑不如CD8+T细胞亚群显著;另外,T淋巴细胞表面CD25的表达虽然较对照组有所下降,但是CD4CD25共表达的细胞却较对照组有明显的上升趋势。T淋巴细胞表面活化抗原HLA-DR的表达较对照组有轻度减低。根据T细胞内因子的变化,Th1和Tc1的比率较对照组有显著降低,而Th2和Tc2的比率却有轻度上升。于共刺激作用下单独培养的T细胞,MSC能轻度抑制其Th1细胞的转化;而在MLC中,MSC则能够明显抑制其中的CD8+T细胞亚群和Th1细胞,轻度提高Th2细胞比率。结论: MSC在体外能够明显抑制T淋巴细胞的增殖,其主要是针对CD8+T细胞。另外,它还能下调活化T淋巴细胞上一些较特异的表面标记CD25和HLA-DR的表达,降低MLC体系中的Th1和Tc1,升高Th2和Tc2。所以在临床上可能有减轻移植后急性移植物抗宿主病的发生,而保留移植物抗白血病的潜力。
[Abstract]:Objective: to investigate the immunomodulatory effect of mesenchymal stem cells (MSCs) on T lymphocyte subsets under different stimulation conditions in vitro. The purpose of this study was to explore the role of mesenchymal stem cell transplantation in the development of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVLL) after transplantation, in order to explore the advantages and potential value of combined transplantation of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs). Methods: normal human bone marrow mononuclear cells were isolated by Ficoll-Hypaque gradient density centrifugation. It was added into mixed lymphocyte culture, MLC) system in different proportion, and the proliferation of T lymphocytes in MLC was detected by MTT colorimetry on the 5th day of the first day of mixed lymphocyte culture. The surface labeling of T lymphocytes and the secretion of IL-4 and IFN- 纬 were analyzed by flow cytometry in MSC co-incubated system or stimulated by phorbol myristate acetatePMA and ionomycinin. Results: in the MLC system with MSC, the inhibition of T lymphocyte proliferation was dose-dependent, and the inhibition degree increased with the prolongation of co-incubation time, among which the suppression of CD8 T cell subsets was less significant than that of CD8 T cell subsets. In addition, the expression of CD25 on the surface of T lymphocytes was lower than that of the control group, but the expression of HLA-DR on the surface of T lymphocytes was slightly lower than that of the control group. The ratio of Th1 and Tc1 was significantly lower than that of the control group, but the ratio of Th2 and Tc2 was slightly increased. Co-stimulated T cells could slightly inhibit the transformation of Th1 cells, while in MLC, CD8 T cell subsets and Th1 cells were significantly inhibited, and the ratio of Th2 cells was slightly increased. Conclusion: MSC can significantly inhibit the proliferation of T lymphocytes in vitro, which is mainly directed at CD8 T cells. In addition, it can down-regulate the expression of CD25 and HLA-DR on activated T lymphocytes, decrease Th1 and Tc1 in MLC system, and increase Th2 and Tc2. Therefore, it may have the potential to reduce the occurrence of acute graft-versus-host disease after transplantation and preserve the potential of graft-versus-leukemia.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R392

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