Abstract: 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.