Linked Life Data

11399141

Source:http://linkedlifedata.com/resource/pubmed/id/11399141

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-6-11
pubmed:abstractText
Pasteurella (Mannheimia) haemolytica leukotoxin (Lkt) and lipopolysaccharide (LPS) are the primary virulence factors contributing to the pathogenesis of lung injury in bovine pneumonic pasteurellosis. Previous studies have characterized in vitro responses of bovine alveolar macrophages (AMs) to Lkt and LPS. Activation of AMs with Lkt or LPS causes induction of proinflammatory cytokines, and Lkt causes cytolysis of AMs at higher concentrations. Since AMs are exposed to both of these bacterial virulence factors during disease, previous studies may have underestimated the possibility of functional interactions between Lkt and LPS. The purpose of this study was to characterize the effect of simultaneous exposure to both Lkt and LPS on AM cytolysis and proinflammatory cytokine expression. Using cellular leakage of lactate dehydrogenase as an indirect measure of cytolysis, we studied AM responses to Lkt alone, LPS alone and Lkt+LPS. We found that 80-200 pg/ml LPS, which does not itself cause cytolysis, synergistically enhanced the cytolysis induced by 2-5 Lkt units (LU)/ml Lkt. Northern blot analysis demonstrated that synergism between Lkt and LPS resulted in increased levels of IL-8 mRNA, and that the kinetic patterns of TNF-alpha and IL-8 mRNA expression induced by Lkt+LPS differed from those induced by each agent separately. Finally, the WEHI 164 (clone 13) bioassay was used to show that Lkt/LPS synergism resulted in enhanced secretion of biologically active TNF-alpha. These results provide direct evidence of synergism between Lkt and LPS in AM cytolysis and inflammatory cytokine expression. Additional studies to characterize the molecular basis of this phenomenon are indicated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0882-4010
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Academic Press.
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
347-57
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Lipopolysaccharide enhances cytolysis and inflammatory cytokine induction in bovine alveolar macrophages exposed to Pasteurella (Mannheimia) haemolytica leukotoxin.
pubmed:affiliation
Department of Veterinary PathoBiology, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55108, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.