An antiinflammatory immunogen from yeast culture induces activation and alters chemokine receptor expression on human natural killer cells and B lymphocytes in vitro

The aim of this study was to evaluate the immunomodulating effects of a consumable yeast-based immunogen, EpiCor, on human leukocytes in vitro. The selection of antiinflammatory and lymphocyte activation assays was based on initial evidence for immunomodulating effects of EpiCor from an unusually low incidence of influenza among employees in a factory manufacturing EpiCor, along with a high oxygen radical absorbance capacity value. In the present study, EpiCor significantly reduced the production of reactive oxygen species by neutrophils (P < .005). EpiCor treatment of peripheral blood mononuclear cells (PBMCs) caused induction of the activation markers CD80 and CD86 on B lymphocytes, and CD69 and CD25 on CD3−CD56+ natural killer cells. This induction was also seen on enriched populations of natural killer and B lymphocytes, suggesting a direct effect not dependent on bystander cells. Coculturing of PBMC with EpiCor and phytohemagglutinin resulted in inhibition of phytohemagglutinin-induced T-cell proliferation and reduction of interferon gamma production. Fucoidan, a ligand for the homing molecule l-selectin (CD62L), is known to induce rapid up-regulation of several chemokine receptors on lymphocytes. EpiCor caused strong inhibition of Fucoidan-mediated expression of the chemokine receptors CXCR4 and CCR9 on PBMC. This suggested rapid altering of signal transduction pathways, or a direct competition for cell surface receptors, with an end result being an altered sensitivity to chemotactic signals from tissue. We conclude that EpiCor possesses significant antiinflammatory activity and induces direct activation and increased chemotactic awareness of lymphocyte subsets in vitro. This suggests further study of effects of EpiCor consumption on antiviral defense mechanisms and antibody production.