Intercellular adhesion molecule 1 and Lymphocyte function-associated antigen 1 interaction (ICAM-1/LFA-1 interaction)

The interaction between Intercellular Adhesion Molecule 1 (ICAM-1) and Lymphocyte Function-associated Antigen 1 (LFA-1) is a fundamental mechanism for leukocyte recruitment and immune signaling. ICAM-1 (CD54) is a member of the immunoglobulin superfamily typically expressed on vascular endothelial cells and antigen-presenting cells, while LFA-1 is an integrin (alphaL beta2) found on the surface of T cells and other leukocytes (UniProt P05362, P20333). This binding event facilitates the firm adhesion of leukocytes to the endothelium, a prerequisite for extravasation into inflamed tissues, and is essential for the formation of the immunological synapse during T-cell receptor engagement (PubMed: 15157670). In pathological states, overactivity of this pathway drives chronic inflammation and autoimmune destruction in diseases such as dry eye disease and psoriasis (StatPearls: NBK538245). Therapeutic interventions, such as the small molecule Lifitegrast or the monoclonal antibody Efalizumab, target this interaction by binding to LFA-1 and preventing its association with ICAM-1, thereby modulating the inflammatory response. While effective, systemic inhibition of this pathway has been associated with safety concerns like increased infection risk and, historically, progressive multifocal leukoencephalopathy.

Other names

CD54/CD11a-CD18 interactionICAM-1/Integrin alpha-L beta-2 interactionLFA-1/ICAM-1 complex

Competitive inhibition of the protein-protein interaction between LFA-1 and ICAM-1 to prevent leukocyte adhesion and activation.