RESUMEN
We analyzed the mechanisms underlying enhanced IgA production in the cells of Peyer's patch cells via membrane vesicles derived from Lactobacillus sakei subsp. sakei NBRC 15893. Depletion of CD11c+ cells from Peyer's patch cells suppressed the enhanced IgA production mediated by membrane vesicles. Meanwhile, the stimulation of bone-marrow-derived dendritic cells with membrane vesicles increased gene expression of inducible nitric oxide synthase, retinaldehyde dehydrogenase 2, and several inflammatory cytokines. The production of nitric oxide and interleukin (IL)-6 by membrane vesicle stimulation was induced via Toll-like receptor 2 on bone marrow-derived dendritic cells. Inhibition of inducible nitric oxide synthase and retinaldehyde dehydrogenase 2, as well as the neutralization of IL-6 in Peyer's patch cells, suppressed the enhanced IgA production by membrane vesicle stimulation. Hence, nitric oxide, retinoic acid, and IL-6 induced by membrane vesicles play crucial roles in the enhanced IgA production elicited by membrane vesicles in Peyer's patch cells.