Macrophage-1 antigen (integrin alpha-M beta-2) (Mac-1)

Mac-1 receptor (Macrophage-1 antigen, integrin alpha-M beta-2, CD11b/CD18, complement receptor 3) is a broadly expressed integrin and pattern recognition receptor on myeloid and lymphoid cells. It mediates cell adhesion, migration, phagocytosis, and recognition of opsonized pathogens via interactions with iC3b, ICAM-1, and numerous extracellular ligands. Mac-1 plays central roles in the innate immune response, inflammation, tissue regeneration, and thrombosis. Therapeutically, Mac-1 blockade is being explored for inflammatory and autoimmune indications, but targeting strategies must balance immune suppression with preservation of essential host defense and regenerative functions.

Other names

Complement receptor 3 (CR3)Integrin alpha-M beta-2CD11b/CD18Macrophage integrin

Ligand-blocking antibodies interrupt adhesion and migration (leukocyte recruitment, inflammation); Inhibition suppresses binding to iC3b, CD40L, and other ligands, reducing immune cell activation and migration; Modulation of phagocytosis and cytokine release.