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...