Bordetella adenylate cyclase toxin interacts with filamentous haemagglutinin to inhibit biofilm formation in vitro

• DOI: 10.1111/mmi.13551
• Publication Date: 2016-10-13T20:53:30Z
• Authors: Casandra Hoffman; Joshua Eby; Mary Gray; F. Heath Damron; Jeffrey Melvin; Peggy Cotter; Erik Hewlett
• Keywords: Adenylate Cyclase Toxin; Bordetella; Bordetella bronchiseptica

Bordetella pertussis, the causative agent of whooping cough, secretes and releases adenylate cyclase toxin (ACT), which is a protein bacterial that targets host cells disarms immune defenses. ACT binds filamentous haemagglutinin (FHA), surface-displayed adhesin, until now, consequences this interaction were unknown. A B. bronchiseptica mutant lacking produced more biofilm than parental strain; leading Irie et al. to propose ACT-FHA could be responsible for inhibition. Here we characterize physical with FHA provide evidence linking inhibition in vitro. Exogenous inhibits formation concentration-dependent manner N-terminal catalytic domain (AC domain) necessary sufficient inhibitory effect. AC Domain interacts C-terminal segment ∼650 nM affinity. does not inhibit by mature (MCD), suggesting direct between MCD required Additionally, disrupts preformed on abiotic surfaces. The demonstrated host-directed represents novel regulatory mechanism identifies an unprecedented role ACT.