Regional control of regulatory immune cells in the intestine.

Purpose of review: The intestine contains the largest compartment of immune regulatory cells which include T regulatory cells and IL-10 producing macrophages. These cell populations serve to restrain unnecessary immune responses of the intestine, which may lead to the pathogenesis of Crohn's disease or food allergy.

Recent findings: This review discusses the recent findings pertaining to the functional regulation of these cells which may provide insight into novel therapies. Both T regulatory cells and macrophages are regulated in microbiota-dependent and microbiota-independent manners, i.e., dietary antigens. Often, this is specific to regional specialization and environment in small intestine vs. colon.

Summary: These immune regulatory cells are largely regulated by microbiota in the colon, whereas in the small intestine, the microbiota has less affect, as seen in germ-free mice studies. Targeting these cells in their specific compartments may direct future treatment modalities for inflammatory bowel disease as ulcerative colitis and Crohn's are vastly different diseases.