Filamentous hemagglutinin protein of Bordetella pertussis (FHA)

Filamentous hemagglutinin (FHA) protein is the principal adhesin and a key virulence factor of Bordetella pertussis, the causative agent of whooping cough. FHA is a large (~230 kDa mature form) surface-associated and secreted protein produced from a precursor called FhaB, processed during secretion via the two-partner secretion (TPS) pathway[1][3][6][7]. FHA mediates high-affinity binding of B. pertussis to ciliated epithelial cells and macrophages in the human respiratory tract, facilitating bacterial adherence, colonization, and evasion of early immune defenses[5][7][3]. FHA is essential for effective lower respiratory tract infection and persistence and is required for full virulence[7][4][5]. Structurally, it features a β-helical scaffold, anchoring it as a prototypical TPS adhesin[1][6]. The protein is a primary component of acellular pertussis vaccines, with the immune response against FHA conferring protection by inhibiting bacterial colonization[3][8]. Persistent research explores its precise structure-function relationships, including its potential roles in immunomodulation and host cell signaling[5]. Caveats and limitations: No canonical small molecule inhibitors targeting FHA are in licensed clinical use. The FHA abbreviation may refer to related proteins in other Bordetellae, but the entry here is specific to Bordetella pertussis. While FHA itself is not a classical receptor in the sense of human physiology, it is a well-defined *bacterial* therapeutic and diagnostic target.

Other names

Filamentous haemagglutininFhaB (gene/protein precursor)Bordetella pertussis FHAPertussis FHA

Vaccination: FHA is targeted by antibodies generated by acellular pertussis vaccines, blocking its adherence to host cells and facilitating immune clearance. Adhesion inhibition: Neutralizing antibodies prevent bacterial attachment to respiratory tissue, impeding infection establishment.