Multiple ICAM-1 (CD54) epitopes are involved in homotypic B-cell adhesion.
Two monoclonal antibodies (MoAbs), F10.2 and F10.3, were selected for their ability to interfere in homotypic adhesion of human B cells. Precipitation studies and binding to intercellular adhesion molecule 1 (ICAM-1, CD54) cDNA transfected COS cells revealed that both MoAbs are directed against ICAM-1. The binding of MoAb F10.2 was inhibited by LB-2, a MoAb recognizing the NH2-terminal immunoglobulin-like domain of ICAM-1. This suggests that the epitope recognized by F10.2 is located on the first domain of the ICAM-1 molecule. Binding of the other MoAb, F10.3, was not inhibited by F10.2 nor by two other MoAbs mapping to the first domain of the ICAM-1 molecule. The ability of F10.3 to bind to ICAM-1 is influenced by glycosylation, suggesting that this epitope is located on one of the domains carrying possible glycosylation sites, i.e. domain 2, 3 or 4. The ICAM-1 epitopes recognized by F10.3 and LB-2 or F10.2 co-operated in homotypic adhesion of cells from the EBV cell line ML1. These results suggest that in addition to an epitope located on domain 1 of the ICAM-1 molecule, another epitope whose exposure can be regulated by glycosylation is involved in homotypic B-cell adhesion of cell line ML1.
Bloemen
P
P
Department of Clinical Immunology, University Hospital, Utrecht, The Netherlands.
Moldenhauer
G
G
van Dijk
M
M
Schuurman
H J
HJ
Bloem
A C
AC
D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000502:physiology*; D002448:Cell Adhesion / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000502:physiology*; D002460:Cell Line; D000939:Epitopes; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006031:Glycosylation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D014162:Transfection; D014415:Tunicamycin
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D000939:Epitopes; D014415:Tunicamycin; D018799:Intercellular Adhesion Molecule-1