effect of different activation mechanism of t cells on immunoregulatory properties of bone marrow mesenchymal stem cells

background: mesenchymal stem cells (msc) have ability to regulate immune response via proinflamatory cytokines. in this study we aimed to investigate the effect of different mechanism for t cell activation and adjacency on immunoregulatory properties of msc. methods: bone marrow mscs were purchased and t cells were obtained from whole blood sample. t cells were activated by two different mechanisms using peripheral blood mononuclear cell (pbmc) and phytohemagglutinin (pha) and then co-cultured with msc using transwell cultures (indirect contact) and usual plate (direct contact). after 96 hours tgf-b concentration in culture medium and indole amine 2, 3-dioxygenase (ido) activity in cell lysate were assayed. we used anova and t-test for statistical analysis and 0.05 was considered as significant level. results:  our result showed a significant increase of tgf-b secretion and ido activity. increase in mixed lymphocyte culture (mlc) groups was more significant than lymphocyte transformation test (ltt) in compare with control. conclusions: the present study confirmed immunoregulatory effect of bm-msc. also this study showed that mlc of bm-mscs and t cells have more immunoregulatory effects than ltt.