Alveolar macrophage and neutrophil interactions in Pasteurella haemolytica-induced endothelial cell injury.
Pasteurella haemolytica, the cause of fibrinous pleuropneumonia in cattle, produces extensive microvascular endothelial cell damage. This study investigated endothelial cell-leukocyte interactions by using a Millicell coculture assay system that modeled the bovine pulmonary alveolar defense system and showed that P. haemolytica-mediated endothelial cell damage was enhanced by the presence of alveolar macrophages, presumably due to soluble alveolar macrophage products. The alveolar macrophage-enhanced endothelial cell damage occurred regardless of the presence of anti-P. haemolytica immune serum; however, neutrophils and immune serum effectively prevented endothelial cell damage. These results suggest that alveolar macrophages are ineffective in controlling P. haemolytica growth and actually promote endothelial cell damage.
Sharma
S A
SA
Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville 37996-4500.
Olchowy
T W
TW
Breider
M A
MA
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000382:microbiology* / Q000473:pathology; D007106:Immune Sera / Q000276:immunology; D016676:Macrophages, Alveolar / Q000276:immunology*; D016978:Mannheimia haemolytica / Q000276:immunology / Q000502:physiology*; D009504:Neutrophils / Q000276:immunology*; D011651:Pulmonary Artery
D007106:Immune Sera