[Immunoregulatory effect of bone marrow mesenchymal stem cells on regulatory T cells in patients with systemic lupus erythematosis].

OBJECTIVE: To study the in vitro modulation of autogeneic and allogenic regulatory T lymphocytes proliferation by bone marrow mesenchymal stem cells (MSCs) in patients with systemic lupus erythematosis (SLE). METHODS: Human MSCs were separated with Percoll (1.073 g/ml) from bone marrow of patients with SLE or healthy subjects. The purity of MSCs was identified with the phenotypes by fluorescence active cell sorter (FACS). The subset regulatory T cells in the peripheral blood of patients with SLE were isolated with magnetic activated cell sorting (MACS) CD4 and CD25 microbeads. Lymphocytes or CD4+ CD25+ T cells isolated from the peripheral blood of SLE patients were cocultured either with autologous MSCs or MSCs from healty donors. The proliferation activities of lymphocytes and CD4+ CD25+ T cells were investigated with methyl thiazolyl tetrazolium( MTr) test. The level of IL-10 and transforming growth factor beta (TGFbeta) was determined with enzyme-linked immunosorbent assay (ELISA). RESULTS: The lymphocyte activity in SLE was suppressed by autogeneic and allogeneic MSCs and the inhibition rate was 56.32% and 65.46%, respectively. A stronger immunosuppressive effect of allogeneic MSCs was detected. MSCs were capable of increasing the proportion of allogeneic and autogeneic regulatory T cells in a dose dependent fashion. MSCs stimulated CD4+ CD25+ T cells to produce IL-10 and TGFbeta. CONCLUSION: MSCs can suppress lymphocyte proliferation and increase CD4+ CD25+ T cells. MSCs might play important roles in immunosuppressant lymphocyte proliferation and be important to cooperate with autogeneic hematopoietic stem cells in transplantation.