Bacterial flagellins: mediators of pathogenicity and host immune responses in mucosa

Flagella contribute to virulence of pathogenic bacteria through chemotaxis, adhesion to and invasion of host surfaces.Flagellin is the structural protein that forms the major portion of flagellar filaments.Thus, flagellin is constituted of a conserved domain widespread in bacterial species dedicated to filament polymerization.Conversely, mammalian hosts detect the conserved domain on flagellin monomers through the Toll-like receptor (TLR) 5 and trigger pro-inflammatory and adaptive immune responses.This review describes the relation among flagellin molecular structure, bacterial virulence, and host defences with special emphasis on mucosal tissues.-88 words -Teaser: Mucosal pathogens use flagella for invasion of host surfaces whereas the host detects and induces defences to pathogen through Toll-like receptor 5 that detects flagellin, the subunit of flagellum.