Intercellular adhesion molecule 3 (ICAM-3) (ICAM3)

Intercellular adhesion molecule 3 (ICAM-3), also known as CD50, is a type I transmembrane glycoprotein and a member of the immunoglobulin superfamily that is constitutively and abundantly expressed on all resting leukocytes (UniProt P32942). It serves as a critical ligand for the integrin LFA-1 (CD11a/CD18), facilitating the initial stages of leukocyte-endothelial interactions and providing essential costimulatory signals for T-cell activation (PubMed: 7511011). Beyond its role in immune cell trafficking, ICAM-3 acts as a key "eat-me" signal on the surface of apoptotic cells, promoting their recognition and clearance by macrophages to prevent secondary necrosis and inflammation (PubMed: 12117813). In clinical contexts, ICAM-3 is implicated in the pathogenesis of various inflammatory and autoimmune diseases, such as psoriasis and rheumatoid arthritis, as well as in the progression and metastasis of certain malignancies (PubMed: 15634778). It also plays a role in viral infections, including HIV-1, by facilitating viral entry and cell-to-cell spread. While direct therapeutic targeting of ICAM-3 has been explored through experimental monoclonal antibodies like ICM3, most clinical interventions currently focus on its primary ligand, LFA-1.

Other names

CD50ICAM-3Intercellular adhesion molecule 3

Antagonism of the ICAM-3/LFA-1 interaction to inhibit leukocyte recruitment and T-cell activation.