title: Cloning and characterization of a new intercellular adhesion molecule ICAM-R.
abstract: The human intercellular adhesion molecules ICAM-1, ICAM-2 and their counter-receptors, the beta 2 or leukointegrins, mediate a variety of homotypic and heterotypic leukocyte and endothelial cell-cell adhesions central to immunocompetence. It has been found that cell-cell adhesion which is dependent on expression of the leukocyte function-associated antigen LFA-1 is not always blocked completely by antibodies raised against ICAM-1 and ICAM-2. Other leukointegrin ligands therefore probably exist, such as a glycoprotein of M(r) 124K that binds LFA-1 and has been designated ICAM-3 on the basis of this function. We have molecularly cloned a new member of the ICAM family, ICAM-R, which is related to ICAM-1 and ICAM-2. The complementary DNA encoding ICAM-R is 1,781 base pairs long and the protein has five extracellular immunoglobulin-family type domains. The mature cell-surface form of the ICAM-R protein has an M(r) which varies from 116 to 140K in a cell type-specific fashion. Overall identities in protein sequence with ICAM-1 and ICAM-2 are 48% and 31% respectively, with the degree of similarity varying between individual domains. The high level of expression of ICAM-R on resting leukocytes of all lineages and its lack of expression on either resting or cytokine-activated endothelial cells indicates a pattern of expression distinct from ICAM-1 and ICAM-2. In common with ICAM-1 and ICAM-2, ICAM-R is a ligand for the beta 2-integrin CD11a/LFA-1 (CD18).
authors.affiliation: ICOS Corporation, Bothell, Washington 98021.
authors.forename: R
authors.initials: R
authors.lastname: Vazeux
authors.forename: P A
authors.initials: PA
authors.lastname: Hoffman
authors.forename: J K
authors.initials: JK
authors.lastname: Tomita
authors.forename: E S
authors.initials: ES
authors.lastname: Dickinson
authors.forename: R L
authors.initials: RL
authors.lastname: Jasman
authors.forename: T
authors.initials: T
authors.lastname: St John
authors.forename: W M
authors.initials: WM
authors.lastname: Gallatin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D004730:Endothelium, Vascular / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D007739:L Cells; D007962:Leukocytes / Q000502:physiology*; D051379:Mice; D008961:Models, Structural; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011487:Protein Conformation; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D004247:DNA