RESVERATROL SIGNIFICANTLY ATTENUATES CELL MEDIATED IMMUNE REJECTION AGAINST XENOGENEIC BOVINE PERICARDIUM

Abstract

Resveratrol is a major bioactive phenol found in red wine and red grapes that has been shown to reduce T cell activation and proliferation through inhibition of protein kinase B (PKB/Akt) and mTOR pathways. Recent studies have shown that humoral and cell-mediated immune reactions cause structural valve deterioration (SVD) in xenograft valves constructed out of bovine pericardium. Thus, tissue engineered heart valves (TEHV) which involve the process of decellularizing bovine pericardium have been developed to reduce xenoreactive immune response. Our study examines whether resveratrol could further reduce cell-mediated immune rejection against xenograft bovine pericardium thereby serving as a potential adjuvant therapy to TEHV. Human peripheral blood mononuclear cells (PBMC) were isolated by Ficoll-Paque gradient centrifugation and resuspended in RPMI 1640 complete medium containing 10% human serum, 2mM L-glutamine, 50 IU penicillin/ml, and 50 ml streptomycin/ml. The cells were further split into a resveratrol-treated group (50μM/ml) and a vehicle-treated group containing ethanol (50μM/ml) and cultured overnight (18hrs) in a 37C 5% CO2 incubator. 2ml of the complete medium from each group containing 1 X 10ˆ6 PBMC cells were then aliquoted into 12-well cell culturing plate with each well containing either native bovine pericardium, decellularized bovine pericardium, allograft pericardium, autograft pericardium, or no pericardium. The exposed culture media were then collected for ELISA analysis after 1 and 3 days. Tumor necrosis factor-a (TNF-a), chiefly produced by macrophages in cell-mediated immunity, were measured. Resveratrol-treated cells showed a significant reduction in all of the tissue exposure types in comparison to vehicle-treated controls at both 1 and 3 days (P < 0.05). Additionally, both vehicle control and resveratrol-treated groups at each time points generated the highest TNF-a concentration with native bovine pericardium exposure followed by the decellularized bovine pericardium, autograft pericardium, allograft pericardium, and no tissue. Resveratrol significantly attenuates cell-mediated immune rejection against xenogenic bovine pericardium exposure to an extent comparable to allograft and autograft human pericardium exposures. Therefore, resveratrol may serve as effective adjuvant therapy in patients receiving TEHV replacements to further decrease the xenogenic immune shown to cause SVD.