CR3: a general purpose adhesion-recognition receptor essential for innate immunity.
CR3 (CD11b/CD18), a beta(2) integrin, has a key role in innate antimicrobial defenses, as evidenced by the leukocyte adhesion (CD18) deficiency syndrome in humans and the CD11b knockout mouse. CR3 is a highly versatile pattern-recognition receptor that activates leukocytes via signaling complexes and actin reorganization, mediates phagocytosis, and promotes leukocyte transmigration.