Bordetella pertussis lipopolysaccharide resists the bactericidal effects of pulmonary surfactant protein A.
Surfactant protein A (SP-A) plays an important role in the innate immune defense of the respiratory tract. SP-A binds to lipid A of bacterial LPS, induces aggregation, destabilizes bacterial membranes, and promotes phagocytosis by neutrophils and macrophages. In this study, SP-A interaction with wild-type and mutant LPS of Bordetella pertussis, the causative agent of whooping cough, was examined. B. pertussis LPS has a branched core structure with a nonrepeating trisaccharide, rather than a long-chain repeating O-Ag. SP-A did not bind, aggregate, nor permeabilize wild-type B. pertussis. LPS mutants lacking even one of the sugars in the terminal trisaccharide were bound and aggregated by SP-A. SP-A enhanced phagocytosis by human monocytes of LPS mutants that were able to bind SP-A, but not wild-type bacteria. SP-A enhanced phagocytosis by human neutrophils of LPS-mutant strains, but only in the absence of functional adenylate cyclase toxin, a B. pertussis toxin that has been shown to depress neutrophil activity. We conclude that the LPS of wild-type B. pertussis shields the bacteria from SP-A-mediated clearance, possibly by sterically limiting access to the lipid A region.
Schaeffer
Lyndsay M
LM
Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA.
McCormack
Francis X
FX
Wu
Huixing
H
Weiss
Alison A
AA
D037361:Adenylate Cyclase Toxin / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D001886:Bordetella pertussis / Q000737:chemistry* / Q000235:genetics / Q000472:pathogenicity; D002240:Carbohydrate Sequence; D005964:Glucosyltransferases / Q000235:genetics / Q000502:physiology; D006801:Humans; D008050:Lipid A / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry*; D008264:Macrophages / Q000502:physiology; D008969:Molecular Sequence Data; D009000:Monocytes / Q000502:physiology; D009504:Neutrophils / Q000502:physiology; D010587:Phagocytosis; D011485:Protein Binding; D037662:Pulmonary Surfactant-Associated Protein A / Q000494:pharmacology*; D014312:Trisaccharides / Q000737:chemistry; D010566:Virulence Factors, Bordetella / Q000737:chemistry* / Q000235:genetics
D037361:Adenylate Cyclase Toxin; D001426:Bacterial Proteins; D008050:Lipid A; D008070:Lipopolysaccharides; D037662:Pulmonary Surfactant-Associated Protein A; D014312:Trisaccharides; D010566:Virulence Factors, Bordetella; C084764:pertussis endotoxin; D005964:Glucosyltransferases; C489633:WaaF protein, Bordetella pertussis