title: Interaction between Pasteurella haemolytica and bovine alveolar macrophages: cytotoxic effect on macrophages and impaired phagocytosis.
abstract: Cultured bovine alveolar macrophages phagocytosed formalized 125I-labeled Pasteurella haemolytica organisms poorly when compared with uptake of an identical number of radiolabeled Yersinia enterocolitica organisms. The presence of immune serum enhanced uptake of P haemolytica, yet at high bacteria-to-macrophage ratios, a significant positive correlation existed between uptake and loss of cells from coverslips. This phenomenon was not observed with Y enterocolitica. While culture supernatant from P haemolytica either impaired phagocytosis or were cytotoxic to cultured macrophages, supernatant from Y enterocolitica did not show this effect. The observation of an apparent deterimental effect on bovine alveolar macrophages after uptake of P haemolytica may be used to explain events occurring in pneumonic pasteurellosis in cattle and may help in the development of immunizaiton techniques.
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D002417:Cattle / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D007106:Immune Sera; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D010325:Pasteurella / Q000276:immunology*; D010587:Phagocytosis / Q000187:drug effects; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000276:immunology; D015007:Yersinia / Q000276:immunology
chemical_list: D001427:Bacterial Toxins; D007106:Immune Sera