A monoclonal antibody, 3/22, to rabbit CD11c which induces homotypic T cell aggregation: evidence that ICAM-1 is a ligand for CD11c/CD18.
The rabbit CD11c molecule has been characterized by use of new monoclonal antibody, mAb 3/22. Expression of the p150,95 integrin (CD11c/CD18) has been shown by flow cytometry and immunohistochemistry to be restricted to monocytes, macrophages, dendritic cells and a small population of lymphocytes in peripheral blood. No expression on neutrophils could be demonstrated. Incubation of the newly derived CD8+ T cell line, BJ/873, with mAb 3/22 causes homotypic aggregation, which has been shown to be cell surface event that is not dependent on intracellular signaling or on receptor cross-linking. Inhibition studies show that the ligands responsible for this aggregation are CD11c/CD18 and ICAM-1, both of which are expressed on BJ/873. One other rabbit T cell line, K34, that also expresses p150,95 and ICAM-1, shows a similar aggregation response when stimulated with 3/22. Cell lines that express p150,95 but not ICAM-1 do not aggregate. These observations suggest that ICAM-1 is a ligand for activated p150,95.
Blackford
J
J
Maxillofacial Surgery Unit, Eastman Dental Institute, London, GB.
Reid
H W
HW
Pappin
D J
DJ
Bowers
F S
FS
Wilkinson
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000494:pharmacology; D000937:Antigen-Antibody Reactions; D001667:Binding, Competitive / Q000276:immunology; D018821:CD18 Antigens / Q000276:immunology; D002413:Cations, Divalent; D002449:Cell Aggregation / Q000276:immunology; D002460:Cell Line; D016130:Immunophenotyping; D016167:Integrin alphaXbeta2 / Q000276:immunology* / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology*; D008024:Ligands; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011817:Rabbits; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013696:Temperature
D000911:Antibodies, Monoclonal; D018821:CD18 Antigens; D002413:Cations, Divalent; D016167:Integrin alphaXbeta2; D008024:Ligands; D018799:Intercellular Adhesion Molecule-1