人胎盘间充质干细胞CD200^+亚群细胞的免疫特性

Immune properties of human CD200^+ sub-population from human placenta-derived mesenchymal stem cells

背景:在不同的研究中,间充质干细胞表现出相悖的免疫特性,这可能是因为间充质干细胞是一群复合细胞,不同的亚群细胞表现出不同的免疫特性。目的:从人胎盘间充质干细胞中分选获得CD200+亚群细胞,探讨该亚群细胞的免疫特性。方法:采用流式细胞方法从人胎盘间充质干细胞中分选出CD200^+亚群细胞,对其进行细胞表型、多向分化潜能鉴定;ELISA方法检测CD200^+亚群细胞的白细胞介素6、白细胞介素8因子分泌量;混合淋巴细胞共培养体系检测CD200^+亚群细胞的免疫调节功能。结果与结论:(1)流式细胞术成功从人胎盘间充质干细胞中分选获得CD200^+亚群细胞,该亚群细胞高表达CD44、CD73、CD105和CD90,而CD34、CD45、CD80和CD86为阴性,具有典型的间充质干细胞表面标志,可诱导分化为脂肪细胞和成骨细胞,分泌高水平的白细胞介素6和白细胞介素8;(2)淋巴细胞共培养体系中,与人胎盘间充质干细胞和CD200-亚群细胞相比,CD200^+亚群细胞能够显著抑制被活化的淋巴细胞增殖,下调干扰素γ、白细胞介素2水平,而白细胞介素10水平明显上调;(3)该研究发现,从人胎盘间充质干细胞中分离获得的CD200^+亚群细胞具有优于胎盘间充质干细胞和CD200^-亚群细胞的免疫调节功能,为其临床应用提供了一定的理论依据。

BACKGROUND:In different studies,mesenchymal stem cells exhibit contradictory immune characteristics.This may be because mesenchymal stem cells are a group of complex cells and different subgroups exhibit different immune characteristics.OBJECTIVE:To isolate and identify a sub-population of placenta-derived mesenchymal stem cells with high positive surface antigen of CD200,and to investigate the immune characteristics of this sub-population.METHODS:Flow cytometry was utilized to sort CD200+placenta-derived mesenchymal stem cells.Phenotypic characterization and multilineage differentiation of the sorted cells were determined.Cytokine secretion,involving interleukin-6 and interleukin-8,was measured by ELISA.Mixed lymphocyte proliferation assay was used to determine the immune characteristics of CD200+placenta-derived mesenchymal stem cells.RESULTS AND CONCLUSION:The CD200+placenta-derived mesenchymal stem cells exhibited homogeneous spindle shape,and highly expressed CD44,CD73,CD90 and CD105,negatively expressed CD34,CD45,CD80 and CD86.After induced differentiation,the cells were positively stained by oil red O staining and alizarlin red staining,which were the markers of adipocytes and osteoblasts.The results of ELISA indicated that the expression level of interleukin-6 and interleukin-8 in the CD200+placenta-derived mesenchymal stem cells was strikingly higher than placenta-derived mesenchymal stem cells and CD200-placenta-derived mesenchymal stem cells.Compared with normal and CD200-placenta-derived mesenchymal stem cells,CD200+placenta-derived mesenchymal stem cells inhibited T cell proliferation significantly,lowered the levels of interferon-γand interleukin-2,and upregulated the level of interleukin-10.We found that CD200+placenta-derived mesenchymal stem cells have better immunoregulatory capability compared with normal and CD200-placenta-derived mesenchymal stem cells,which may provide an ideal theoretical basis for clinical use.