Pertussis toxin and acellular pertussis antigens (PT/aP antigens)

Pertussis toxin (PT) and related acellular pertussis antigens, including filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM), are the primary molecular components used in acellular pertussis vaccines to prevent whooping cough (Source: CDC, "Pertussis Biology"). PT is a complex AB5-type exotoxin that functions by ADP-ribosylating the inhibitory G-protein alpha subunit (Gi alpha) in host cells, which leads to unregulated cyclic AMP production and impaired immune cell function (Source: UniProt, P04977). The accompanying antigens—FHA, PRN, and FIM—are surface-exposed proteins that facilitate the attachment of Bordetella pertussis to the respiratory epithelium, a crucial step for bacterial colonization (Source: PubMed, PMID: 25135745). In the context of immunization, these antigens are purified and the toxin is detoxified to induce a robust humoral and cellular immune response without causing disease (Source: FDA, "DAPTACEL"). These antigens are the targets of neutralizing antibodies that prevent bacterial adhesion and neutralize the systemic effects of the toxin (Source: StatPearls, "Pertussis"). While these targets have significantly reduced the burden of pertussis, a major challenge is the waning of vaccine-induced immunity over time, which has led to a resurgence of the disease in some populations (Source: NIH, "Pertussis Vaccine Research"). Additionally, some strains of Bordetella pertussis have begun to show "antigenic drift," such as the loss of pertactin expression, to evade the vaccine-induced immune response (Source: CDC, "Pertactin-Deficient B. pertussis").

Other names

Pertussis toxinFilamentous hemagglutininPertactinFimbriae types 2 and 3PTFHAPRNFIM

Induction of active immunity through the production of neutralizing antibodies and memory T-cell responses against Bordetella pertussis virulence factors and adhesins.