Immunoregulatory effects of rat bone marrow mesenchymal stem cells on T cells

Objective:To study the immunoregulatory effects of rat bone marrow mesenchymal stem cells on T cells in vitro.Methods:MSCs from bone marrow of rat were isolated and cultured in vitro.The morphological characterization of MSCs was observed after Wright-Giemsa staining and the typical molecules on the cell surface were identified by flow cytometry(FCM).ConA was used as stimuli origin.Effect of MSCs on proliferation of T cells was determined by MTT method.Effects of MSCs on IFN-γand IL-4 secretion of T cells were determined by ELISA assay.Effect of MSCs on apoptotic level of T cells was studied by FCM.The effect of MSCs on cytotoxicity of CTL was investigated by MTT method.Results:Proliferation of T cells were decreased obviously after cocultivated with different numbers of MSCs in a dose-dependent manner compared with positive control(P0.01).The level of IFN-γ secreted by T cells was decreased while the level of IL4 was increased significantly in a dose-dependent manner(P0.01).The apoptosis of T cells was not induced by MSCs.After treated by MSCs,cytotoxicity of CTL was impaired compared with the control group(P0.05).Conclusion:MSCs could inhibit the proliferation of T cells and the cytotoxicity of CTL in vitro.These effects were related to inducing cytokine secretion but not apoptosis of T cells.