Mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1)

Mucosal vascular addressin cell adhesion molecule 1 (MAdCAM‑1) is a type I transmembrane glycoprotein of approximately 60 kDa that belongs to the immunoglobulin superfamily. It is primarily expressed on endothelial cells in mucosal tissues such as the intestine, Peyer’s patches, mesenteric lymph nodes, and other sites including the liver during certain diseases. Its main function is to mediate selective homing of lymphocytes—particularly those expressing integrins α4β7 and α4β1—into mucosa-associated lymphoid tissue by binding these integrins as well as L-selectin. This process plays a crucial role in maintaining gut immune homeostasis but also contributes to pathological leukocyte infiltration during chronic inflammatory conditions like inflammatory bowel disease. Therapeutically targeting the interaction between MAdCAM‑1 and its ligands has shown promise for treating IBD by reducing inappropriate leukocyte migration into inflamed intestinal tissue. Drugs such as ontamalimab are monoclonal antibodies designed to block this pathway specifically in the gut without broadly suppressing systemic immunity.

Other names

MAdCAM1AddressinMucosal addressin cell adhesion molecule 1

Monoclonal antibodies block the interaction between MAdCAM‑1 and integrins (especially α4β7), inhibiting lymphocyte recruitment to inflamed gut tissue and reducing inflammation.