Response of Sheep after Localized Deposition of Lipopolysaccharide in the Lung

Abstract

Deposition by fiberoptic bronchoscopy of lipopolysaccharide (LPS) from Pasteurella haemolytica (Type 1A) or Escherichia coli (Type 026:B6) into the lungs of sheep elicited a variety of clinical and pathologic reactions. Sheep given P. haemolytica LPS developed a biphasic hematologic response: a marked decline in leukocyte counts in 4 h that was followed in 18 h by a mild leukocytosis. A gradual rise in leukocyte counts was seen in sheep given E. coli LPS. Neutrophil counts gradually increased after deposition with either LPS, but lymphocyte counts fluctuated with the total leukocyte counts. Body temperature remained normal after LPS deposition. A marked increase in total lung lavage cell counts was observed 22 h after LPS deposition. Up to 83% of the lavage cells were neutrophils. Both LPS induced diffuse fibrinopurulent inflammation, edema, hyperemia, and hemorrhage in the lungs. LPS from P. haemolytica also caused foci of necrosis. In contrast, distilled water caused diffuse edema and hyperemia, with a limited number of neutrophils. Deposition of P. haemolytica or E. coli LPS into the lungs of sheep resulted in lesions similar to those reported in animals with an acute pneumonia experimentally induced with gram-negative bacteria.

TLRs 2 and 4 Are Not Involved in Hypersusceptibility to Acute Pseudomonas aeruginosa Lung Infections

“…LPS or endotoxins have been implicated in the pathogenesis of acute lung disease because of the demonstration that the instillation of LPS from Escherichia coli and Pasteurella hemolytica into the lungs of animals produced lesions similar to those seen in animals with experimentally induced, acute Gram-negative pneumonia (24). The subsequent observations that intratracheal administration of LPS induced IL-1␤ and TNF-␣ expression as well as an inflammatory infiltrate (25) suggested that LPS was an important virulence factor in the pathogenesis of Gram-negative bacterial pneumonia.…”

Influence of β2-Integrin Adhesion Molecule Expression and Pulmonary Infection withPasteurella haemolyticaon Cytokine Gene Expression in Cattle

“…Several virulence factors of P. haemolytica have been identified (15). Lipopolysaccharide (LPS) and leukotoxin are the best-known stimulators of inflammation in bovine pneumonic pasteurellosis (11,13,15,42,46,47,49,50). These virulence factors stimulate a variety of respiratory tract cells such as alveolar and intravascular macrophages, mast cells, and endothelial cells, and these cells express and produce inflammatory mediators.…”

Effects of co‐exposure of lipopolysaccharide and β‐glucan (Zymosan A) in exacerbating murine allergic asthma associated with Asian sand dust

“…Exposure to LPS is associated with an increased risk of asthma in humans (Alexis, Eldridge, & Peden, ; Smit et al, ). Exposure to LPS also induces acute lung injury and neutrophil accumulation (Brogden, Cutlip, & Lehmkuhl, ; Kindt, Gadek, & Weiland, ; Sudo et al, ). The level of LPS exposure may impact the immune reactivity.…”