The pertussis agent Bordetella pertussis produces a number of virulence factors, of which the filamentous hemagglutinin (FhaB) plays a role in B. pertussis adhesion to epithelial and phagocytic cells. Moreover, FhaB was recently found to play a crucial role in nasal cavity infection and B. pertussis transmission to new hosts. The 367 kDa FhaB protein translocates through an FhaC pore to the outer bacterial surface and is eventually processed to a ~220 kDa N-terminal FHA fragment by the SphB1 protease. A fraction of the mature FHA then remains associated with bacterial cell surface, while most of FHA is shed into the bacterial environment. Previously reported indirect evidence suggested that FHA, or its precursor FhaB, may bind the β2 integrin CD11b/CD18 of human macrophages. Therefore, we assessed FHA binding to various cells producing or lacking the integrin and show that purified mature FHA does not bind CD11b/CD18. Further results then revealed that the adhesion of B. pertussis to cells does not involve an interaction between the bacterial surface-associated FhaB and/or mature FHA and the β2 integrin CD11b/CD18. In contrast, FHA binding was strongly inhibited at micromolar concentrations of heparin, corroborating that the cell binding of FHA is ruled by the interaction of its heparin-binding domain with sulfated glycosaminoglycans on the cell surface.

• Keywords
• Bordetella pertussis, CD11b/CD18, adenylate cyclase toxin, filamentous hemagglutinin, heparin, integrin,
• MeSH
• CD18 Antigens MeSH
• Bacterial Adhesion MeSH
• Adhesins, Bacterial metabolism   MeSH
• Bordetella pertussis * metabolism   MeSH
• Virulence Factors, Bordetella MeSH
• Glycosaminoglycans MeSH
• Hemagglutinins metabolism   MeSH
• Heparin MeSH
• Integrins MeSH
• Humans MeSH
• Macrophage-1 Antigen MeSH
• Whooping Cough * MeSH
• Peptide Hydrolases MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• CD18 Antigens MeSH
• Adhesins, Bacterial MeSH
• Virulence Factors, Bordetella MeSH
• Glycosaminoglycans MeSH
• Hemagglutinins MeSH
• Heparin MeSH
• Integrins MeSH
• Macrophage-1 Antigen MeSH
• Peptide Hydrolases MeSH