Bordetella pertussis fimbrial antigen (FIM)

Bordetella pertussis fimbrial antigens, primarily consisting of the major subunits Fim2 and Fim3, are long, filamentous surface structures essential for the attachment of the bacterium to the host's respiratory tract (PMID: 10506018). These proteins function as adhesins, facilitating the colonization of ciliated epithelial cells, which is a vital step in the development of pertussis, or whooping cough (CDC, 2022). Beyond their role in adhesion, fimbriae are highly immunogenic and are classified as agglutinogens due to their ability to elicit antibodies that cause bacterial clumping (WHO, 2015). In modern medicine, these antigens are key components of multi-component acellular pertussis vaccines, such as DTaP and Tdap (FDA, 2023). By including fimbrial antigens, these vaccines induce the production of specific antibodies that block bacterial attachment and promote opsonophagocytosis. Research indicates that the presence of fimbrial antigens in vaccine formulations correlates with enhanced protection against both clinical disease and asymptomatic carriage of the pathogen (PMID: 15501770).

Other names

FimbriaePiliAgglutinogensSerotype 2 fimbriaeSerotype 3 fimbriaeFim2Fim3Agglutinogen 2Agglutinogen 3

Induction of humoral immunity through the production of specific IgG antibodies that block bacterial adhesion to respiratory epithelial cells and facilitate opsonophagocytosis.