Procyanidin- and polysaccharide-induced γδ T cell priming

We recently characterized the capacity of procyanidins and polysaccharides found in common dietary supplements to stimulate innate immunity. Our studies focused on γδ T cells, innate lymphocytes found in mucosal epithelium and well positioned to encounter and respond to agonists found in dietary supplements. Higher order oligomeric procyanidins, such as those found in unripe apple peel (APP) and polysaccharides from plant bark (Yamoa(tm)) primed γδ T cells. Priming of γδ T cells results in rapid increases in innate cytokine expression and enhanced responses to secondary stimuli. Intraperitoneal injection of either procyanidin or polysaccharide agonists induced rapid peritonitis in mice. Feeding Yamoa(tm) extract to calves altered peripheral blood leukocyte responses. Although both procyanidins and polysaccharides primed γδ T cells, they acted via different mechanisms. Whereas procyanidins directly primed γδ T cells, polysaccharides required accessory cells such as monocytes for optimal priming. Procyanidi...