Homing of intestinal immune cells.

The homing of immune cells into the intestinal mucosa, the gut-associated lymphoid tissue or the mesenteric lymph nodes involves a complex process of molecular events that is dependent on cell type and cell maturation. Key factors that collectively determine the homing of leukocytes and their interaction with resident endothelial, epithelial, stromal and immune cells are interactions between integrins or selectins with their tissue adhesion molecules as well as chemokine receptors and their ligands. The organization of the small and large intestinal tissue and the mucosa associated lymphoid tissue as well as the presence or absence of inflammatory stimuli influence the homing of intestinal immune cells. The homing pattern of intestinal dendritic cells and CD4+ T cells and its role for the pathogenesis and regulation of inflammatory bowel disease are discussed