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.