ITGAL

The ITGAL gene encodes integrin alpha L (CD11a), which pairs with β2 subunit (CD18) to form lymphocyte function-associated antigen-1 (LFA-1). This heterodimeric cell-surface receptor mediates lymphocyte adhesion and transendothelial migration by binding ICAM-1/2/3 ligands. It is critical for immune synapse formation, T-cell activation, and leukocyte trafficking. Dysregulated LFA-1 activity is implicated in autoimmune pathologies, including rheumatoid arthritis, psoriasis, and transplant rejection, as well as hematologic malignancies like T-cell acute lymphoblastic leukemia.
Therapeutic strategies targeting LFA-1 have focused on blocking its interaction with ICAMs. Early monoclonal antibodies (e.g., efalizumab) showed efficacy in psoriasis but were withdrawn due to systemic immunosuppression risks. Recent efforts emphasize small-molecule antagonists (BMS-817399) and allosteric modulation to reduce infection susceptibility. Dual targeting of LFA-1 with PD-1/CTLA-4 inhibitors is under preclinical evaluation for solid tumors. Challenges remain in optimizing tissue specificity and balancing immunomodulatory effects.