Effects of resveratrol on Th17 cell-related immune responses under tacrolimus-based immunosuppression

BACKGROUND: We previously reported that tacrolimus (Tac) does not decrease T helper 17 cells (Th17) response in kidney transplantation. In this study, we evaluated whether Resveratrol (Resv) has immunosuppressive effects by decreasing Th17 responses in Tac-based immunosuppression. METHODS: We investigated the effects of Resv under Tac-treatment conditions, on CD4(+) T cell differentiation to Th17 cells in peripheral blood mononuclear cells (PBMCs), and proliferation of CD4(+) T cells co-cultured with human renal proximal tubular epithelial cells (HRPTEpiCs). The effects of Resv on Th17 cells were tested in the murine skin transplant model. RESULTS: In PBMCs, Tac did not but combination of Tac and Resv further suppressed Th17 immune response. In the co-culture study, combination of Resv to Tac significantly decreased HRPTEpiC-induced T cell proliferation compared to Tac alone. Resv treatment in the Jurkat cell induced the expression of AMP-activated protein kinase and suppressed the expression of mammalian target of rapamycin (mTOR), suggesting blocking Th17 pathway by Resv. In the murine skin transplant model, combination of Resv to Tac significantly prolonged skin graft survival accompanied by the suppression of Th17 cells, compared to either the Tac-alone or control groups. CONCLUSION: The results of our study suggest that Resv provides additional immunosuppressive effects to Tac by suppressing effector CD4(+) T cells, especially Th17 cells, in the transplantation setting.