Low Endotoxic Potential of Legionella pneumophila Lipopolysaccharide due to Failure of Interaction with the Monocyte Lipopolysaccharide Receptor CD14
AUTOR(ES)
Neumeister, B.
FONTE
American Society for Microbiology
RESUMO
Legionella pneumophila, a gram-negative bacterium causing Legionnaires’ disease and Pontiac fever, was shown to be highly reactive in in vitro gelation of Limulus lysate but not able to induce fever and the local Shwartzman reaction in rabbits and mice. We analyzed the capacity of purified L. pneumophila lipopolysaccharide (LPS-Lp) to induce activation of the human monocytic cell line Mono Mac 6, as revealed by secretion of proinflammatory cytokines and desensitization to subsequent LPS stimulation. We showed that despite normal reactivity of LPS-Lp in the Limulus amoebocyte lysate assay, induction of cytokine secretion in Mono Mac 6 cells and desensitization to an endotoxin challenge required LPS-Lp concentrations 1,000 times higher than for LPS of Salmonella enterica serovar Minnesota. Therefore, we examined the interaction of LPS-Lp with the LPS receptor CD14. We demonstrated that LPS-Lp did not bind to membrane-bound CD14 expressed on transfected CHO cells, nor did it react with soluble CD14. Our results suggest that the low endotoxic potential of LPS-Lp is due to a failure of interaction with the LPS receptor CD14.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=108499Documentos Relacionados
- Human monocyte CD14 is upregulated by lipopolysaccharide.
- Interaction of Pulmonary Surfactant Protein C with CD14 and Lipopolysaccharide
- Lactoferrin Inhibits the Endotoxin Interaction with CD14 by Competition with the Lipopolysaccharide-Binding Protein
- Proteolysis of monocyte CD14 by human leukocyte elastase inhibits lipopolysaccharide-mediated cell activation
- Heterotrimeric G proteins physically associated with the lipopolysaccharide receptor CD14 modulate both in vivo and in vitro responses to lipopolysaccharide.