Adhesion molecules mediating recruitment of monocytes to inflamed tissue.
Three families of cell-surface proteins are largely responsible for the adherence of leukocytes to cells and matrices: integrins, immunoglobulin (Ig)-related molecules and selectins. Blood monocytes express beta 1 integrins VLA-4, -5 and -6 and beta 2 integrins CD11a/CD18, CD11b/CD18 and CD11c/CD18. These cells also express the Ig-related molecules ICAM-1, -2 and -3, ligands for the beta 2 integrins. In addition, monocytes express L-selectin and the oligosaccharides Lex and sialyl Lex, ligands for the endothelial selectins E- and P-. In vitro studies with blocking antibodies have identified adhesion molecules participating in the adherence of monocytes to one another, to T lymphocytes and to vascular endothelial cells. These antibodies also block adhesion-dependent monocyte activities, such as cytotoxicity of tumor cells, antigen presentation, phagocytosis of large particles, induction of cytokine secretion, formation of multinucleated giant cells and HIV-induced syncytium formation. In vivo studies in animals have demonstrated participation of L-selectin and CD11b/CD18 in monocyte accumulation in inflamed peritoneum. Moreover, treatment with anti-CD11b antibodies potentiates primary listeriosis and inhibits the macrophage recruitment and granuloma formation, and anti-CD18 antibodies block ear swelling in Mycobacterium tuberculosis-immunized animals following challenge with PPD. Adhesion molecules may also play key roles in the pathogenesis of tuberculosis and AIDS.
Patarroyo
M
M
Microbiology and Tumorbiology Center, Karolinska Institute, Stockholm, Sweden.
D000163:Acquired Immunodeficiency Syndrome / Q000209:etiology; D000818:Animals; D002448:Cell Adhesion / Q000276:immunology / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000502:physiology*; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D007962:Leukocytes / Q000276:immunology / Q000473:pathology / Q000502:physiology; D009000:Monocytes / Q000276:immunology / Q000473:pathology / Q000502:physiology*; D014376:Tuberculosis / Q000209:etiology
D015815:Cell Adhesion Molecules