ICAM-1 (Intercellular Adhesion Molecule-1), also known as CD54. is a cell surface glycoprotein belonging to the immunoglobulin superfamily. It plays a critical role in mediating leukocyte adhesion and transmigration during inflammatory responses by binding to integrins like LFA-1 (lymphocyte function-associated antigen-1) on immune cells. ICAM-1 is constitutively expressed at low levels on endothelial cells, epithelial cells, and certain immune cells, but its expression is strongly upregulated by pro-inflammatory cytokines (e.g., TNF-α, IL-1β) or microbial products during infection, injury, or autoimmune conditions.
ICAM-1 antibodies are valuable tools for research and therapeutic applications. In research, they are used to block ICAM-1 interactions, study leukocyte trafficking mechanisms, or detect ICAM-1 expression in disease models (e.g., atherosclerosis, cancer, rheumatoid arthritis). Therapeutically, anti-ICAM-1 monoclonal antibodies have been explored to dampen pathological inflammation or immune activation. For instance, they may inhibit leukocyte infiltration in organ transplant rejection or autoimmune disorders. Some antibody-drug conjugates or radiolabeled ICAM-1 antibodies are also investigated for targeted delivery in cancer or imaging.
Notably, soluble ICAM-1 (sICAM-1) levels in blood are often monitored as a biomarker of endothelial dysfunction or disease severity. While no ICAM-1-targeted antibody has been fully approved yet, preclinical and clinical studies highlight its potential in modulating immune-driven pathologies. Challenges include balancing efficacy with off-target effects due to ICAM-1's broad expression roles in homeostasis and disease.