[Regulatory T cells in the treatment of autoimmune myositis in mice: efficacy and mechanism].

OBJECTIVE: To investigate effect of CD4(+) CD25(+) Foxp3(+) Tregs in the treatment of autoimmune myositis (EAM) in mice and explore the possible mechanisms. METHODS: Mouse models of EAM were divided randomly into model group and treatment group, and the latter received infusion of CD4(+) CD25(+) Foxp3(+) Tregs separated from normal mouse spleen by magnetic activated cell sorting. The changes of muscle pathology was observed, and the expression of PD-1 and CTLA-4 in spleen CD4(+) CD25(+) Foxp3(+) Tregs was analyzed using flow cytometry; peripheral blood IL-10 and TGF-β levels were tested using double antibody sandwich ELISA. RESULTS: Compare with the model group, the mice in the treatment group showed significantly reduced muscular inflammatory cell infiltration, increased blood levels of IL-10 and TGF-β (P<0.05), and increased expression of PD-1 and CTLA-4 in spleen CD4(+) CD25(+) Foxp3(+) Tregs (P<0.05). CONCLUSION: CD4(+) CD25(+) Foxp3(+) Tregs reinfusion produces therapeutic effect in mice with EAM by increasing peripheral blood IL-10 and TGF-β levels and PD-1 and CTLA-4 expressions in spleen CD4(+) CD25(+) Foxp3(+) Tregs.