Intestinal mucosal immunity requires the ability to induce a proinflammatory response to clear invasive pathogens while also maintaining self-tolerance in the face of continuous immune activation by luminal contents. Regulatory T cells (Tregs) expressing the transcription factor Foxp3 promote immunologic homeostasis by suppressing dendritic cells1 and effector T-cell responses through the production of transforming growth factor β, interleukin (IL)10, and IL35.2 In this manner, Foxp3+ Tregs play a central role in the development of oral tolerance to food antigens and commensal bacteria.
