Functional role of flagellin in bacterial flagellar assembly and immune receptor activation: structure and application

초록

Flagellin constitutes the flagellar filament that provides bacteria with locomotion and allows pathogens to invade thehost tissue as a virulence factor. The N-terminal and C-terminal domains of flagellin are functionally important in filamentformation and are highly conserved across diverse bacterial species. In the host, the conserved flagellin of pathogenicbacteria activates the innate immune receptors, including Toll-like receptor 5 (TLR5) and NOD-like receptor C4 (NLRC4),and functions as a pathogen-associated molecular pattern that alarms the host immune system. Recently, an array ofstructural studies has revealed flagellin-mediated immune receptor activation mechanisms, which can provide deepinsights into the development of immune-modulating vaccines and therapeutics. In this review, we explain the biologicalfunctions and structural properties of flagellin in filament formation and immune activation and describe the application offlagellin to vaccine and drug development.