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5212910 
Journal Article 
Interaction of bacterial lipopolysaccharide with mouse surfactant protein C inserted into lipid vesicles 
Augusto, L; Le Blay, K; Auger, G; Blanot, D; Chaby, R 
2001 
Yes 
American Journal of Physiology: Lung Cellular and Molecular Physiology
ISSN: 1040-0605
EISSN: 1522-1504 
281 
4 
L776-L785 
English 
11557581 
Infection of the respiratory tract is a frequent cause of lung pathologies, morbidity, and death. When bacterial endotoxin [lipopolysaccharide (LPS)] reaches the alveolar spaces, it encounters the lipid-rich surfactant that covers the epithelium. Although binding of hydrophilic surfactant protein (SP) A and SP-D with LPS has been established, nothing has been reported to date on possible cross talks between LPS and hydrophobic SP-B and SP-C. We designed a new binding technique based on the incorporation of surfactant components to lipid vesicles and the separation of unbound from vesicle-bound LPS on a density gradient. We found that among the different hydrophobic components of mouse surfactant separated by gel filtration or reverse-phase HPLC, only SP-C exhibited the capacity to bind to a tritium-labeled LPS. The binding of LPS to vesicles containing SP-C was saturable, temperature dependent, related to the concentrations of SP-C and LPS, and inhibitable by distinct unlabeled LPSs. Unlike SP-A and SP-D, the binding of SP-C to LPS did not require calcium ions. This LPS binding capacity of SP-C may represent another antibacterial defense mechanism of the lung.