Figure 2.

Intestinal microbiota immunological mechanism against FA. 1: inhibits HDAC through the GRP109A receptor, acting on CD103 and promoting Treg differentiation; 2: induces RALPH activity, also acting on CD103; 3: inhibits the FcεRI receptor, decreasing degranulation and thereby the expression of proinflammatory cytokines; 4: Treg expresses FOXP3 and synthesizes inhibitory cytokines such as IL-10 and TGF-β; 5: CD25, expressed by Treg FOXP3, is capable of decreasing effector T cell proliferation. All these mechanisms contribute to microbiota homeostasis and the gaining of tolerance.