Bordetella pertussis virulence factors affect phagocytosis by human neutrophils.
The interaction between human neutrophils and wild-type Bordetella pertussis or mutants expressing altered lipopolysaccharide or lacking virulence factors-pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, filamentous hemagglutinin (FHA), pertactin, or BrkA-was examined. In the absence of antibodies, the wild-type strain and the mutants, with the exception of mutants lacking FHA, attached efficiently to neutrophils. The addition of opsonizing antibodies caused a significant reduction (approximately 50%) in attachment of the wild-type strain and most of the mutants expressing FHA, suggesting that bacterium-mediated attachment is more efficient than Fc-mediated attachment. Phagocytosis was also examined. In the absence of antibodies, about 12% of the wild-type bacteria were phagocytosed. Opsonization caused a statistically significant reduction in phagocytosis (to 3%), possibly a consequence of reduced attachment. Phagocytosis of most of the mutants was similar to that of the wild type, with the exception of the mutants lacking adenylate cyclase toxin. About 70% of the adenylate cyclase toxin mutants were phagocytosed, but only in the presence of opsonizing antibody, suggesting that Fc receptor-mediated signaling may be needed for phagocytosis. These studies indicate that FHA mediates attachment of B. pertussis to neutrophils, but adenylate cyclase toxin blocks phagocytosis.
Weingart
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CL
Department of Molecular Genetics, University of Cincinnati, Cincinnati, Ohio 45267-0524, USA.
Weiss
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AA
D000262:Adenylyl Cyclases / Q000502:physiology; D018829:Adhesins, Bacterial / Q000502:physiology; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology; D001886:Bordetella pertussis / Q000276:immunology* / Q000472:pathogenicity; D006388:Hemagglutinins / Q000502:physiology; D006801:Humans; D009504:Neutrophils / Q000276:immunology*; D009876:Operon; D009895:Opsonin Proteins / Q000502:physiology; D010587:Phagocytosis; D014774:Virulence; D010566:Virulence Factors, Bordetella
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; C090007:BrkA protein, Bordetella pertussis; D006388:Hemagglutinins; D009895:Opsonin Proteins; D010566:Virulence Factors, Bordetella; C065273:filamentous hemagglutinin adhesin, Bordetella pertussis; D000262:Adenylyl Cyclases