Mesenchymal stem cells suppress T-lymphocyte responses by indoleamine 2,3-dioxygenase activity / 中国病理生理杂志

ABSTRACT

AIM: To investigate the influence of mesenchymal stem cells (MSCs) expressing indoleamine 2, 3-dioxygenase (IDO) activity on the allogeneic T-lymphocyte responses.METHODS: MSCs were isolated and cultured from human bone marrow. Selected surface markers of MSCs were detected by flow cytometry and their morphologic characteristics were determined by microscopy. The pluripotentiality of MSCs was also studied. IDO mRNA and IDO protein expressions in MSCs induced by γ-interferon (IFN-γ) at the concentration of 2×105 U/L were detected. MSCs induced by IFN-γ at the concentration of 2×105 U/L were plated in dishes and then mixed lymphocyte reaction (MLR) cultures were set up. T-lymphocytes proliferation was determined by MTT assays and IDO activity was measured by high-performance liquid chromatography (HPLC). RESULTS: IFN-γ could stimulate IDO mRNA and IDO protein expressions in MSCs. IDO enzyme activity in induced MSCs inhibited T-lymphocyte proliferation of MLR cultures. CONCLUSION: MSCs could suppress T-lymphocyte responses via IDO enzyme activity in vitro.