Effects of IL-7 on the phenotype and function of inducible Tregs

Previous study confirmed that serum IL-7 level is correlated with the severity of acute GVHD.This study designed to study the effects of IL-7 on the phenotype and function of inducihle regulatory T cells(iTregs).CD4~+CD25~- T cells were isolated from spleen of C57BL/6 mice by magnetic activated cell sorting(MACS),then the cells were induced in vitro with anti-CD3,anti-CD28,TGF-β,IL-2 and retinoic acid for 7 days until cells expressed CD4~+CD25~+,defined as iTregs.Then the phenotype and suppressive activity of iTregs were analyzed by flow cytometry after be stimulated with IL-7 for 24 h.The expressions of CD39(P=0.0007) and CTLA-4(P=0.0110);of iTregs were significantly decreased after 10 ng/ml IL-7 intervention,and the suppressive activity of iTregs was also significantly decreased(P=0.001 3),furthermore,the apoptosis of iTregs was significantly increased(P=0.002 0).These combined data suggested that the suppressive activity of iTregs was obviously decreased in the environment of high concentration IL-7,which indicates that iTregs therapy may not achieve the desired effect in patients of immune disorders with internal environment of high concentration IL-7.