Filamentous hemagglutinin and related acellular pertussis antigens (FHA/aP)

Filamentous hemagglutinin (FHA) is a large, 220 kDa cell-surface protein produced by Bordetella pertussis that functions as a major adhesin, facilitating the attachment of the bacterium to ciliated respiratory epithelial cells and macrophages (UniProt P03398). In addition to FHA, acellular pertussis (aP) vaccines typically include other key antigens such as pertussis toxin (PT), pertactin (PRN), and fimbriae types 2 and 3 (FIM2/3), which collectively serve as the primary targets for vaccine-induced immunity (CDC, 2022). These antigens are essential for the pathogenesis of pertussis, or whooping cough, by enabling colonization and suppressing the host's innate immune response through various mechanisms, including the ADP-ribosylation of G proteins by PT (UniProt P04977). Drugs interacting with these targets are primarily vaccines, such as DTaP and Tdap, which provide purified versions of these proteins to stimulate the production of neutralizing antibodies and memory T-cell responses (Edwards and Decker, 2023). While these antigens have significantly improved the safety profile of pertussis immunization compared to older whole-cell vaccines, a major therapeutic challenge is the relatively rapid waning of immunity, which has contributed to a resurgence of pertussis in some populations (Kilgore et al., 2016). Consequently, these antigens remain a central focus of research aimed at developing next-generation vaccines with increased durability and broader protection.

Other names

FHAPertussis toxinPTPertactinPRNFimbriae type 2Fimbriae type 3FIM2/3Bordetella pertussis antigens

Induction of active immunity through the production of neutralizing antibodies and memory B and T cells against Bordetella pertussis virulence factors, preventing bacterial attachment and neutralizing toxins.