Cloning and Expression of N-teminal Domain of Pseudomonas aeruginosa Flagellin and Evaluation of Antibodies Raised against it on Motility Inhibition of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen that causes severe and lethal infections in immunocompromised individuals. This bacterium possesses a single polar flagellum. Flagellum and its subunit Flagellin play important roles in the pathogenesis of P. aeruginosa. Flagellin induces immune responses by interaction of its N-terminal domain with TLR-5. Our main aims of this study were cloning and expression of N-terminal domains of flagellin and evaluation of antibodies raised against it on motility inhibition of P. aeruginosa. The DNA sequence coding for the first 161 amino acids of flagellin was PCR amplified and cloned into a pET-28a expression vector. Recombinant protein was over expressed in BL-21(DE3), and purified by Ni-NTA resin. The immune reactivity of recombinant truncated flagellin was evaluated by Western blotting. The recombinant protein was injected into a rabbit and antibodies raised against it were evaluated for the cell motility inhibition of P. aeruginosa 8821M. The N-terminal domain of Flagellin was successfully overexpressed in Escherichia coli BL-21(DE3) host strain. Anti-native and anti-N-terminal flagellin antibodies reacted with the recombinant protein. Motility inhibition assay demonstrated that polyclonal antiserum against N-teminal flagellin is able to inhibit the motility of P. aeruginosa 8821M. The N-terminal domain of flagellin may be used for development of a new recombinant vaccine against P. aeruginosa infections.