人骨髓间充质干细胞诱导成软骨细胞过程中免疫原性改变的实验研究

目的 探讨人骨髓来源间充质干细胞（BMSCs）诱导分化成软骨细胞过程中协同刺激分子的表达及其对细胞免疫原性改变的影响。方法 用密度梯度离心法分离骨髓，体外培养BMSCs，经形态学观察、流式细胞仪鉴定后诱导成软骨样细胞，用流式检测细胞表面协同刺激分子的表达情况;将未分化的BMSCs及诱导后的成软骨样细胞分别与T细胞共培养，采用3H-TdR法检测T细胞的增殖情况。结果 人BMSCs不表达或低表达协同刺激分子CD28、CD80、CD83、CD86，抑制T细胞增殖；而诱导后的成软骨细胞上调表达CD28、CD80、CD83、CD86，并促进T细胞增殖。结论 人BMSCs对T细胞增殖有抑制作用；而诱导后的成软骨细胞免疫原性增强，促进T细胞增殖。

Alterations of immunogenicity in the differentiation from human bone marrow derived mesenchymal stem cells to chondrocytes

Objective   To investigate expressions of co-stimulatory molecules and their effects on alterations of immunogenicity on human bone marrow derived mesenchymal stem cells and differentiated chondrocytes. Methods    Human bone marrow mesenchymal stem cells (BMSCs) were isolated by density gradient centrifugation and confirmed by an inverted phase contrast microscope and flow cytometry (FCM). BMSCs were induced to differentiate into chondrocytes. Expressions of co-stimulatory molecules were quantified by FCM. T cells were incubated respectively with undifferentiated BMSCs and chondrocytes, while the 3H-TdR incorporation method was carried out to evaluate T cell proliferation. Results     BMSCs did not express co-stimulatory molecules CD28, CD80, CD83 and CD86，but  inhibited the proliferation of T cells. Expressions of CD28, CD80, CD83, and CD86 in hBMSCs and differentiated chondrocytes were up-regulated and proliferation of T cells was promoted. Conclusion     BMSCs can inhibit proliferation of T cells in vitro by increasing immunogenicity of BMSC-differentiated chondrocytes.