Integrin alpha E (ITGAE) (ITGAE)

Integrin alpha E (ITGAE), commonly referred to as CD103, is a transmembrane protein that non-covalently associates with the integrin beta 7 subunit to form the alpha E beta 7 heterodimer. This integrin is uniquely expressed on intraepithelial lymphocytes (IELs) and specific subsets of dendritic cells within mucosal environments, such as the gastrointestinal tract, lungs, and skin. Its primary ligand is E-cadherin, an adhesion molecule found on epithelial cells, and their interaction is essential for the localization and retention of T cells within the mucosal epithelium. In inflammatory conditions like ulcerative colitis and Crohn's disease, alpha E beta 7+ T cells are significantly enriched and contribute to tissue damage through the secretion of pro-inflammatory cytokines and cytotoxic molecules. Therapeutic agents like etrolizumab target the beta 7 subunit to disrupt both alpha 4 beta 7-mediated homing and alpha E beta 7-mediated retention, providing a gut-selective mechanism for treating inflammatory bowel disease. However, the clinical development of such therapies has faced challenges in demonstrating consistent efficacy across all patient populations, and potential safety concerns include an increased susceptibility to mucosal infections.

Other names

CD103HML-1HUMINAEIntegrin alpha-IELAntigen CD103Human mucosal lymphocyte antigen 1 alpha polypeptide

Antagonism of the alpha E beta 7 heterodimer (typically via the beta 7 subunit) to block its interaction with E-cadherin, thereby inhibiting the retention of pro-inflammatory intraepithelial lymphocytes in mucosal tissues.