ITGB2

Integrin β2 (ITGB2), also known as CD18, is a transmembrane glycoprotein that forms heterodimers with α subunits (CD11a, CD11b, CD11c, or CD11d) to constitute leukocyte-specific integrins, including LFA-1 (αLβ2), Mac-1 (αMβ2), and others. These adhesion molecules mediate immune cell interactions with endothelial cells, extracellular matrix, and other cells through binding to ligands such as ICAMs, fibrinogen, and complement fragments. Functionally, ITGB2-containing integrins regulate leukocyte adhesion, migration, and immunological synapse formation during inflammation and immune responses. Key pathways involve cytoskeletal reorganization via focal adhesion kinase (FAK) and activation of pro-inflammatory signals through MAPK and NF-κB. Mutations in ITGB2 cause leukocyte adhesion deficiency type 1 (LAD-I), characterized by recurrent infections and impaired wound healing. Therapeutic strategies targeting β2 integrins include LFA-1 antagonists (e.g., lifitegrast for dry eye disease) and Mac-1 inhibitors under investigation for autoimmune disorders. Gene therapy approaches for LAD-I have shown promise in preclinical models, with clinical trials underway.