Bioactive compounds from Concord grapes prime γδ T cells and reduce DNA strand breaks

Abstract

Our overall objective is to determine if bioactive compounds can prime a γδ T cells and reduce inflammation. Previously, we have found that L‐theanine primes γδ T cells, thus, we asked if other small polyphenolic molecules will act similarly, perhaps because they resemble pathogenic secretions as hypothesized for L‐theanine. We tested the hypothesis that bioactive compounds from Concord grapes might also prime this particular cell, which is important in wound healing, pathogen eradication and cancer immunosurveillance. A randomized, double blind, placebo controlled human study was conducted for 9 weeks. We examined peripheral blood mononuclear cells (PBMC) and γδ T cell proliferation, and DNA strand breaks. A repeated measure 2‐way ANOVA with primary effect of Time and secondary effect of Treatment was performed. Despite no significant effect on PBMC proliferation, γδ T cell numbers were significantly higher after juice consumption (p=0.045) and their proliferation under ex vivo autologous serum was significantly greater than the placebo (p=0.044)). The number of intrinsic DNA strand breaks was reduced after consumption of either juice or placebo, however, only juice consumers had a reduced number of strand breaks when cells were challenged with H2O2 compared to placebo (p=0.017). Funded by Welch Foods Inc and the UF/IFAS Agriculture Experiment Station