Bordetella pertussis fimbrial antigens type 2 and 3 (Fim2/3)

Bordetella pertussis fimbrial antigens type 2 and 3 (Fim2 and Fim3) are major surface-exposed filamentous proteins that function as adhesins, facilitating the attachment of the bacterium to the ciliated respiratory epithelium of the host (PMID: 10417483). These fimbriae are critical for the colonization phase of pertussis infection and are recognized as potent agglutinogens that stimulate a protective immune response (PMID: 15271927). Structurally, they are composed of major subunits (Fim2 or Fim3) and a minor tip adhesin, FimD, which mediates specific binding to host receptors (PMID: 11133474). In clinical practice, Fim2 and Fim3 are key components in several multi-component acellular pertussis vaccines, such as DTaP and Tdap, where they induce neutralizing antibodies that block bacterial adherence (PMID: 25135307). The expression of these antigens is regulated by phase variation, allowing the bacteria to adapt to host immune pressures and potentially leading to the emergence of vaccine-escape strains (PMID: 24501087). Monitoring the serotype distribution of Fim2 and Fim3 is essential for evaluating vaccine efficacy and understanding the molecular epidemiology of Bordetella pertussis (PMID: 18936731).

Other names

Fimbriae type 2 and 3Agglutinogen 2Agglutinogen 3Serotype 2 fimbriaeSerotype 3 fimbriaeFim2Fim3

Induction of specific antibodies (agglutinins) that inhibit bacterial adherence to respiratory epithelial cells and promote opsonophagocytosis.