Immunohistochemical Localization of Pasteurella haemolytica Al-derived Endotoxin, Leukotoxin, and Capsular Polysaccharide in Experimental Bovine Pasteurella Pneumonia

Binding of Pasteurella haemolytica leukotoxin to bovine leukocytes.

Pasteurella haemolytica is the principal bacterial pathogen in the bovine respiratory disease complex. This organism produces an exotoxin (referred to as leukotoxin) during logarithmic-phase growth that is a potent leukocyte-modulating agent. At low concentrations, it activates neutrophils and mononuclear phagocytes to release inflammatory mediators, while at the same time making these cells de...

Activation of bovine neutrophils by partially purified Pasteurella haemolytica leukotoxin.

In this study we developed a new method for the partial purification of Pasteurella haemolytica leukotoxin by size-exclusion high-performance liquid chromatography. The partially purified leukotoxin had a molecular weight of 104,000, as estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reacted on an immunoblot with an antileukotoxin monoclonal antibody. As expect...

Pulmonary Endothelial Cells by Pasteurella haemolytica Leukotoxin

In this study, we used an in vitro coculture system to determine which virulence factor from Pasteurella haemolytica Al was responsible for augmenting bovine polymorphonuclear neutrophil (PMN)-mediated killing of bovine pulmonary artery endothelial cells (BPAEC). A 5"Cr release cytotoxicity assay was used as a measure of BPAEC killing. The mechanisms associated with this BPAEC killing were also...

Lipopolysaccharide complexes with Pasteurella haemolytica leukotoxin.

The presence of lipopolysaccharide (LPS) in gram-negative bacterial repeats-in-toxin (RTX) toxin preparations, as well as the harsh conditions required to remove it, suggests that LPS may complex with RTX toxins. Concentrated culture supernatant (CCS) preparations of the RTX toxin Pasteurella haemolytica leukotoxin (LKT) contained LKT and LPS as the most prominent components, with LKT and LPS c...

Different Signaling Pathways Elevation in Bovine Alveolar Macrophages by and Endotoxin Induce Intracellular Calcium A1-Derived Leukotoxin Pasteurella haemolytica