脂肪基质干细胞对异基因T淋巴细胞的作用及机制探讨

Effects of adipose stromal stem cells on allogenetic T lymphocytes and their possible roles in immunoregulation

目的:研究脂肪基质干细胞(ASC)对异基因T淋巴细胞的作用,探讨ASC发挥免疫调节作用的方式和可能机制。方法:将ASC上清和ASC分别与异基因T淋巴细胞进行混合培养。MTT法检测T细胞的增殖,AnnexinⅤ法检测凋亡,流式细胞术检测T细胞中CD4+CD25+细胞的比例,ELISA法检测T细胞分泌IL-10和TGF-β1的水平,RT-PCR法检测Foxp3基因的表达。结果:ASC上清对T淋巴细胞的增殖和凋亡无明显影响。ASC对T淋巴细胞的生长有抑制作用,但对其凋亡无影响。ASC上清和ASC均能增加CD4+CD25+T细胞在T淋巴细胞中的比例,增加T细胞分泌IL-10和TGF-β1的水平,上调Foxp3基因的表达。结论:ASC能通过细胞直接接触和分泌细胞因子的方式分别作用于T淋巴细胞,发挥免疫负调节作用。

Objective：To study the in vitro effect of adipose stromal stem cells（ASC） on phenotype and secretion of cytokines of allogenetic T lymphocytes,and to elucidate the possible roles of ASC for immunomodulation.Methods：ASC was isolated and cultured.The supernatant of ASC and ASC itself were co-cultured with allogenetic T lymphocytes.MTT assays were used to detect the proliferative rates of T cells.Annexin-Ⅴ/PI staining was used to detect apoptotic rates,and flow cytometry to detect the proportion of CD4^＋CD25^＋ cells.ELISA was used to detect the secretion of IL-10 and TGF-β1.Reverse transcription-polymerase chain reaction（RT-PCR） was used to detect the expressing level of Foxp3 gene.Results：The supernatant of ASC had no deep impact on the proliferation and apoptosis of T lymphocytes.ASC had the direct inhibitory effect on growth of T lymphocytes,while the stem cells did not affect apoptosis.Both the supernatant of ASC and ASC itself increased the proportion of CD4^＋CD25^＋ cells in T lymphocytes,and increasd the level of IL-10 and TGF-β1.They could also up-regulate expressing level of Foxp3 in T cells.Conclusion：ASC can affect the function of T lymphocytes via cell-to-cell contact and secretion of cytokines.By these ways ASC exhibits negative immunomodulation and plays an important role in inducing immune tolerance.