Abstract:

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.

Key words: Mesenchymal stem cell; Co-stimulatory molecules; Chondrocytes; Immunogenicity