Surface-associated filamentous hemagglutinin induces autoagglutination of Bordetella pertussis

Abstract

Filamentous hemagglutinin (FHA) is a major adhesin produced by BordeteUla pertussis, the etiologic agent of whooping cough. FHA has been shown to be surface associated but is also secreted by virulent bacteria. Microscopic observations of lungs of mice infected with B. pertussis showed that the bacteria grow as clusters within the alveolar lumen. When B. pertussis was cultivated in vitro with chemically defined medium, bacteria grew as aggregates, mimicking growth observed in vivo. This aggregation was abolished by the addition of cyclodextrin (CDX) to the growth medium and depended on the production of FHA, because a mutant lacking the FHA structural gene failed to form aggregates in a CDX-free medium. Western blot (immunoblot) analyses revealed that, in the absence of CDX, FHA was attached to the bacterial surface and was not efficiently released into the growth medium. Hydrophobic chromatography of FHA showed that CDX drastically reduced the hydrophobicity of FHA, suggesting a direct binding of CDX to FHA, which was further supported by the partial protection of FHA from trypsin digestion in the presence of CDX. In addition, free FHA can interact in a CDX-inhibitable manner with solid phase-immobilized FHA. It can therefore be postulated that the B. pertussis aggregates are most likely due to direct FHA-FHA interaction. Bordetella pertussis, the etiologic agent of whooping cough, produces several virulence-associated adhesion factors such as

Structure‐function analysis of the self‐recognizing Antigen 43 autotransporter protein from Escherichia coli

“…Many bacteria, notably pathogens, have the ability to form aggregates in vitro and in vivo. Examples include a diverse range of bacteria of both Gram-positive and -negative origin such as B. pertussis (Menozzi et al, 1994), Mycobacterium tuberculosis (Menozzi et al, 1996), Staphylococcus aureus (McDevitt et al, 1994) and Streptococcus pyogenes (Frick et al, 2000). Such aggregates are known to be able to resist various host defences, e.g.…”

Structural alterations in a type IV pilus subunit protein result in concurrent defects in multicellular behaviour and adherence to host tissue

“…Although multicellular aggregative behaviour is a common feature of mucosal pathogens and cell-cell aggregation is often associated with adhesin expression, the significance of these associations remains largely unknown. In addition to those species expressing Tfp, other adhesins that are associated with self-aggregative behaviour include the M proteins of group A streptococci (Caparon et al, 1991), filamentous haemagglutinin in Bordetella pertussis (Menozzi et al, 1994), the YadA protein of Yersinia (Tamm et al, 1993) and Opa proteins of N. gonorrhoeae (Swanson, 1978). Recent evidence suggests that type 1 fimbriae of E. coli (Pratt and Kolter, 1998) and Salmonella typhimurium (Thankavel et al, 1999), which are unrelated to Tfp, also contribute to aggregative processes.…”

Pseudomonas aeruginosa uses a cyclic‐di‐GMP‐regulated adhesin to reinforce the biofilm extracellular matrix

“…FHA is an adhesin with multiple binding sites and activities which include binding to cilia in a galactose-inhibitible manner (Tuomanen et al, 1988), integrin recognition required for binding to macrophages (Relman et al, 1990), aggregation that is abolished by the addition of cyclodextrin (Menozzi et al, 1994a), and binding to laryngeal epithelial cells (van den Berg et al, 1999). FHA is responsible for B. pertussis growth as aggregates within the alveolar lumen of murine lungs and these clusters are similar to the aggregates that are observed when B. pertussis is cultivated in vitro (Menozzi et al, 1994a). FHA is a secreted protein that is 500 Angstroms in length and predicted to form a rod-shaped molecule with a beta-helical structure (Kajava et al, 2001).…”