Induction of Treg cells in the mouse colonic mucosa: A central mechanism to maintain host–microbiota homeostasis

CD4+ regulatory T (Treg) cells expressing the transcription factor forkhead box P3 (Foxp3) play a critical role in maintaining immunological homeostasis. Treg cells are highly abundant in the mouse intestinal lamina propria, particularly in the colon. Recent studies using germ-free and gnotobiotic mice have revealed that specific components of the intestinal microbiota influence the number and function of Treg cells. Substantial changes in the composition of microbiota have been associated with inflammatory bowel disease. In this review, we will discuss recent findings that associate intestinal microbiota in mice with Treg responses and with the maintenance of intestinal immune homeostasis.