A subpopulation of Mac-1 (CD11b/CD18) molecules mediates neutrophil adhesion to ICAM-1 and fibrinogen.
We report that a subpopulation (10%) of the Mac-1 (CD1 1b/CD18) molecules on activated neutrophils mediates adhesion to ICAM-1 and fibrinogen. We describe a novel mAb (CBRM1/5) that binds to an activation-specific neoepitope on a subset of Mac-1 molecules on neutrophils and monocytes after stimulation with chemoattractants or phorobol esters but does not recognize Mac-1 on resting myeloid cells. CBRM1/5 immunoprecipitates a subpopulation of Mac-1 molecules from detergent lysates of neutrophils, binds to immunoaffinity-purified Mac-1, and localizes to the I domain on the alpha chain of Mac-1. Because CBRM1/5 recognizes a fraction of Mac-1 on activated neutrophils, but still blocks Mac-1-dependent adhesion to fibrinogen and ICAM-1, we suggest that only a small subset of Mac-1 molecules is competent to mediate adhesion.
Diamond
M S
MS
Committee on Cell and Developmental Biology, Harvard Medical School, Boston, Massachusetts.
Springer
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TA
D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000502:physiology*; D018845:CD11 Antigens; D018821:CD18 Antigens; D016466:CHO Cells; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D018799:Intercellular Adhesion Molecule-1; D016209:Interleukin-8 / Q000494:pharmacology; D007700:Kinetics; D016177:Macrophage-1 Antigen / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D016028:Receptors, Leukocyte-Adhesion / Q000502:physiology*; D013696:Temperature; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018845:CD11 Antigens; D018821:CD18 Antigens; D015815:Cell Adhesion Molecules; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D016209:Interleukin-8; D016177:Macrophage-1 Antigen; D016028:Receptors, Leukocyte-Adhesion; D018799:Intercellular Adhesion Molecule-1; D009240:N-Formylmethionine Leucyl-Phenylalanine; D005340:Fibrinogen; D013755:Tetradecanoylphorbol Acetate