title: A novel rat monoclonal antibody directed against a population of activated mouse peritoneal macrophages.
abstract: A hybridoma clone secreting rat monoclonal antibody (MAB) designated as 3F3.5F and which reacted with a population of activated tumoricidal mouse peritoneal macrophage (M phi) was produced by the fusion of mouse myeloma cells with rat spleen cells immunized against adherent BCG-activated mouse peritoneal exudate cells (adherent BCG-PEC). The antibody was cytotoxic and of the rat IgM class. The specific reactivity of the antibody with mouse primary cells and cell lines was examined by complement-dependent cytotoxicity and indirect immunofluorescence flow cytometry analysis. The antibody was found to bind to about 40% of the adherent BCG-PEC activated in vivo and elicited peritoneal macrophages activated in vitro by lymphokine and lipopolysaccharide (LPS), to about 35% of polymorphonuclear neutrophils (PMN) 15 hr after intraperitoneal injection of BCG, to about 30% of bone marrow cells from BCG-infected mice, to about 10% of P815 mastocytoma cells and to thioglycollate-induced PEC to some degree. It did not bind to other cells tested including BCG-induced peritoneal lymphocytes, non-tumoricidal PEC, thymocytes, spleen cells, resting bone marrow cells from normal mice, lymphomas, myelomas, fibroblasts, or macrophage-cell lines. Pretreatment of adherent BCG-PEC with MAB 3F3.5F and rabbit complement caused a considerable decrease in tumor cytotoxicity toward P815 cells, but the same pretreatment of non-adherent BCG-PEC had no inhibitory effect on natural killer activity for YAC-1 cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000954:Antigens, Surface / Q000276:immunology; D001854:Bone Marrow Cells; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D007694:Killer Cells, Natural / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008222:Lymphokines / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000276:immunology; D013045:Species Specificity; D013154:Spleen / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D008070:Lipopolysaccharides; D008222:Lymphokines