title: A human intercellular adhesion molecule (ICAM-1) distinct from LFA-1.
abstract: Homotypic adhesion by phorbol ester-stimulated lymphocytes requires LFA-1 and Mg+2 and does not involve like-like interactions between LFA-1 molecules on adjacent cells. The latter finding suggested that a second molecule, distinct from LFA-1, also participates in LFA-1-dependent adhesion. The identification of such a molecule was the object of this investigation. After immunization with LFA-1-deficient EBV-transformed lymphoblastoid cells, a MAb was obtained that inhibits phorbol ester-stimulated aggregation of LFA-1+ EBV lines. This MAb defines a novel cell surface molecule, which is designated intercellular adhesion molecule 1 (ICAM-1). ICAM-1 is distinct from LFA-1 in both cell distribution and structure. In SDS-PAGE, ICAM-1 isolated from JY cells is a single chain of Mr = 90,000. As shown by MAb inhibition, ICAM-1 participates in phorbol ester-stimulated adhesion reactions of B lymphocyte and myeloid cell lines and T lymphocyte blasts. However, aggregation of one T lymphocyte cell line (SKW-3) was inhibited by LFA-1 but not ICAM-1 MAb. It is proposed that ICAM-1 may be a ligand in many, but not all, LFA-1-dependent adhesion reactions.
mesh_terms: D000911:Antibodies, Monoclonal / Q000502:physiology; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology*; D001667:Binding, Competitive; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002449:Cell Aggregation; D002460:Cell Line; D005110:Extracellular Space / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D011233:Precipitin Tests
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D016169:Lymphocyte Function-Associated Antigen-1