Objective To investigate the regulation of Sertoli cells on differentiation balance of allogeneic regulatory T cell (Treg)and T helper cell(Th17).Methods Sertoli cells ,bone marrow‐derived dendritic cells(DC) and T lymphocytes were iso‐latedandculturedinvitro.SertolicellsandDCcellswereco‐culturedwithallogeneicTcells,respectively.MorphologyofSertoli cells were verified under the light microscope and electron microscope. The expression of major histocompatibility complex (MHC)‐Ⅱ and B7‐H1 in Sertoli cells was detected by Western blot.Concentration of cytokines[transforming growth factor (TGF)‐β1 and IL‐17A etc. ] in supernatant was determined by enzyme linked immunosorbent assay(ELISA). The frequency of Treg cells differentiated from na?ve T cells was estimated by flow cytometry.Results Sertoli cells were successfully isolated and cultured in vitro.Western blot results showed the expression of MHC‐Ⅱ and B7‐H1 on Sertoli cells surface was increased significantly ,when Sertoli cells were co‐cultured with allogeneic na?ve CD4+ T cells(CD4+ CD62 L+CD25)in vitro.ELISA re‐sults showed the TGF‐β1 concentration in culture supernatant was significantly increased [from (174.89 ± 23.51) pg/mL to (823.10 ± 59.07) pg/mL ,P<0.05] .Flow cytometry results showed Na?ve T cells(CD4+CD62 L+CD25-)were induced to dif‐ferentiate into CD25+ Foxp3+ T cells(from <1.0% up to 27.6% )by co‐cultured with Sertoli cells.And incubation with Sertoli/Treg supernatant(STS)significantly reduced the concentration of IL‐17A in the mixed culture supernatant of DC cells /Na?ve CD4+ T cell[from (361.58 ± 80.27) pg/mL to (137.54 ± 52.19) pg/mL ,P<0.05]. The percentage of IL‐17A+ T cells subset was also significantly decreased(27.2% to 17.9% ,P<0.05).Conclusion The anti‐inflammatory cytokines and immune sup‐
pressive cytokines derived from Sertoli cells can induce allogeneic na?ve T cells to differentiate into CD25+ Foxp3+ Treg cells in vitro.Sertoli cells can regulate the differentiation balance of allogeneic Treg/Th17 to induce the immune tolerance.