Pertussis toxin and related pertussis antigens (PT/FHA/PRN/FIM)

Pertussis toxin (PT) and related antigens, including filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM), are the primary virulence factors of Bordetella pertussis, the causative agent of whooping cough (StatPearls, 2023). PT is a complex AB5-type exotoxin that enters host cells and ADP-ribosylates inhibitory G-proteins, leading to unregulated cAMP levels and disrupted immune signaling (UniProt P04977). FHA, PRN, and FIM function as critical adhesins that allow the bacteria to bind to the ciliated respiratory epithelium, facilitating colonization and local tissue damage (PubMed: 21539931). These antigens are the central components of modern acellular pertussis vaccines, such as DTaP and Tdap, which aim to elicit a robust humoral immune response (CDC, 2022). By generating antibodies against these targets, the vaccines neutralize the toxin's systemic effects and inhibit the initial stages of bacterial infection. However, the emergence of PRN-deficient strains and the phenomenon of waning immunity present ongoing therapeutic challenges and drive the need for next-generation vaccine development (PubMed: 24302518).

Other names

Bordetella pertussis antigensWhooping cough antigensPertussis toxin (PT)Filamentous hemagglutinin (FHA)Pertactin (PRN)Fimbriae types 2 and 3 (FIM2/3)

Induction of active immunity through the production of neutralizing antibodies that prevent bacterial attachment to respiratory cells and neutralize the enzymatic activity of the pertussis toxin (CDC, 2022).