title: The lymphocyte function-associated antigen 1 I domain is a transient binding module for intercellular adhesion molecule (ICAM)-1 and ICAM-3 in hydrodynamic flow.
abstract: The I domain of lymphocyte function-associated antigen (LFA)-1 contains an intercellular adhesion molecule (ICAM)-1 and ICAM-3 binding site, but the relationship of this site to regulated adhesion is unknown. To study the adhesive properties of the LFA-1 I domain, we stably expressed a GPI-anchored form of this I domain (I-GPI) on the surface of baby hamster kidney cells. I-GPI cells bound soluble ICAM-1 (sICAM-1) with a low avidity and affinity. Flow cell experiments demonstrated a specific rolling interaction of I-GPI cells on bilayers containing purified full length ICAM-1 or ICAM-3. The LFA-1 activating antibody MEM-83, or its Fab fragment, decreased the rolling velocity of I-GPI cells on ICAM-1-containing membranes. In contrast, the interaction of I-GPI cells with ICAM-3 was blocked by MEM-83. Rolling of I-GPI cells was dependent on the presence of Mg2+. Mn2+ only partially substituted for Mg2+, giving rise to a small fraction of rolling cells and increased rolling velocity. This suggests that the I domain acts as a transient, Mg2+-dependent binding module that cooperates with another Mn2+-stimulated site in LFA-1 to give rise to the stable interaction of intact LFA-1 with ICAM-1.
authors.affiliation: Center for Immmunology and Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: R
authors.initials: R
authors.lastname: Knorr
authors.forename: M L
authors.initials: ML
authors.lastname: Dustin
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D000943:Antigens, Differentiation; D001665:Binding Sites; D001667:Binding, Competitive; D015153:Blotting, Western; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement; D003001:Cloning, Molecular; D006224:Cricetinae; D017261:Glycosylphosphatidylinositols / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D018715:Microscopy, Video; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules; D017261:Glycosylphosphatidylinositols; C483616:ICAM3 protein, human; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1; D010738:Type C Phospholipases; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D008274:Magnesium