Effect of CD4~+CD25~+T cells on activation of natural killer cells

Objective To explore the possible role of CD4+CD25+T cells stimulated with ConA on natural killer(NK) cells and to determine the effect of TGF-β1 molecule on this actions.Methods CD4+CD25+T cells and NK cells were obtained from Balb/c mice splenocytes by MACS.Fresh isolated CD4+CD25+T cells activated by ConA in vitro for 24h then auto-NK cells were added into the culture.Anti-TGF-β1 antibody was added into the co-culture system.51Cr labeled YAC-1 was used to detect NK cells cototocixity at 24h and 48h.Results Naive CD4+CD25+T displayed a suppressive activity on NK cells and the inhibition rate was 50.8% at 24h and 49.1% at 48h.The inhibition rate of ConA activated CD4+CD25+T cells was 19% at 24h and 20.9% at 48h.When anti-TGF-β1 antibody added,the inhibition rate of naive T cells was-0.1% and 0.25% was respectively while that of ConA activated T cells was 25.2% and 16.3% kespectively.Conclusion In vitro,CD4+CD25+T cells stimulated by Con A can more significantly inhibit the function of NK cells than naive CD4+CD25+T cells.TGF-β1 plays different roles on this action in different inhibition systems.