| Abstract: | AIM: To investigate the effect and mechanism of Foxp3-transduced CD4+CD25-T cells on the cytotoxicity of NK cells. METHODS: Retroviral Foxp3 gene transfection was applied to nave CD4+CD25-T cells. Fresh transduced CD4+Foxp3+ T cells were co-cultured with NK cells. ［51Cr］ labeled YAC-1 cells were used to detect NK cells cytotoxicity. The anti-TGF-β antibody was added into the co-culture system to detect the TGF-β blocking effect. Also the transwell co-culture system was used to investigate the regulatory effect of Treg cells on NK cells. RESULTS: One week after transduction, 38.0% of Foxp3-transduced T cells showed GFP expression by flow cytometry. Foxp3-transduced CD4+CD25-T cells suppressed function of NK cells. The inhibition rates of Foxp3 transduced CD4+CD25- T cells were 42.9% at 24 h and 22.7% at 48 h. When anti-TGF-β antibody was added to the co-culture system, the inhibition rate of CD4+Foxp3+ T cells was 3.2% and 2.1%, respectively. CONCLUSION: CD4+Foxp3+ T cells significantly inhibit the cytolytic function of NK cells. TGF-β plays different roles on this action in different inhibition systems. The inhibitory effect of Treg cells on NK cells is cell-to-cell contact dependent and associates with TGF-β expression. |
