Flagellin A (FlaA) (FlaA)

Flagellin A (FlaA) is the major structural subunit of the bacterial flagellar filament in several significant human pathogens, including Legionella pneumophila, Campylobacter jejuni, and Helicobacter pylori [4, 7, 13]. It is essential for bacterial motility, enabling the pathogens to navigate through viscous environments, colonize host tissues, and evade certain host defenses [6, 10, 18]. Beyond its role in locomotion, FlaA is a potent immunomodulator recognized by the host's innate immune system via Toll-like receptor 5 (TLR5) and the NAIP5/NLRC4 inflammasome [17, 21]. This recognition triggers a robust pro-inflammatory response, including the production of cytokines like IL-8 and TNF-alpha, which are crucial for controlling the infection [1, 11]. Due to its high conservation and strong immunogenicity, FlaA is a primary candidate for the development of recombinant and DNA vaccines aimed at preventing diseases such as Legionnaires' disease and campylobacteriosis [2, 3, 15]. Furthermore, its ability to activate TLR5 makes it a subject of interest for use as a vaccine adjuvant and in therapeutic strategies to enhance innate immunity [14, 21, 25].

Other names

Major flagellinFlagellar filament protein AflaA protein

Induction of protective humoral and cellular immune responses through antigenic presentation and TLR5 activation.