Gut Microbiota Modulation on Intestinal Mucosal Adaptive Immunity

Figure 1

The intestinal microbiota modulate the intestinal mucosal adaptive immunity and interactions between immune cells. The intestinal microbiota, their components, and metabolites contribute to the regulation of innate and adaptive immune responses during homeostasis and dysbiosis states. Under homeostatic conditions, microbiota and microbial metabolites contribute to the intestinal immunological tolerance via Tregs and sIgA. Tolerogenic DCs contribute to the induction of Tregs and sIgA production by IL-10 secretion. Bacterial components such as SCFAs are potent inducers of Tregs and B cells and promote IFN-γ production from CD8⁺ T cells. Microbiota, SCFAs, and IL-21 secreted from the Tfh in the PP contribute to the secretion of bacteria-specific sIgA. Segmented filamentous bacteria induce SFB-specific Th17 cell production. Tregs modulate DCs and Th17 cells mediated by TGF-β. DCs and sIgA negatively regulate the function of Th17 cells.