α4β7 integrin

Class

Anti-integrin monoclonal antibody

Pathway

Leukocyte trafficking / gut-selective adhesion

α4β7 integrin is a cell-surface adhesion protein expressed on a subset of circulating lymphocytes. It binds MAdCAM-1, a molecule displayed on the blood vessels that supply the intestinal lining, and this interaction directs those lymphocytes specifically into gut tissue. This selective homing step is part of the broader leukocyte trafficking pathway, in which combinations of integrins and their vascular counter-receptors route immune cells to particular organs. In chronic inflammatory bowel conditions, sustained recruitment of activated lymphocytes into the intestinal wall perpetuates local inflammation and tissue damage. Blocking α4β7, using either a monoclonal antibody or an oral small molecule, prevents these lymphocytes from engaging MAdCAM-1 and limits their entry into the gut, reducing local inflammatory activity without broadly suppressing circulating immunity. Because α4β7 signaling is largely confined to gut-homing lymphocytes, targeting this specific integrin, rather than the α4 subunit it shares with α4β1 (which governs trafficking into the central nervous system and other tissues), aims to achieve gut-restricted immune modulation. This selectivity underlies interest in the mechanism for inflammatory bowel disease, where controlling lymphocyte entry into the intestine is desired while preserving immune surveillance elsewhere in the body.