Protection against Legionnaire's Disease: Recombinant Flagellin A of < b > < i > Legionella pneumophila < /i > < /b > Can Induce Protective Immunity against Bacteremia in a BALB/c Murine Model

To investigate the immunoprotective effects of the recombinant type A flagellin (FLA), theflaA gene ofLegionella pneumophila serogroup 1 strain Paris was cloned into pET28a(+). Recombinant FLA (rFLA) was overexpressed inE. coli BL21 (DE3) and purified by Ni2+ exchange chromatography. Female BALB/c aged 6-8 weeks were immunized with 20 μg of rFLA. Nonimmunized mice along with mice inoculated with a sublethal dose of liveL. pneumophila intravenously were considered as negative and positive controls, respectively. A significant serum antibody response was observed in female BALB/c mice immunized with rFLA. Production of IFN-#x03B3; and IL-12, and TNF- α in the serum and the splenocyte cultures, and antigen-specific splenocyte proliferation suggested a strong innate and adaptive cell-mediated immunity response in rFLA-immunized mice. Intravenous lethal challenge withL. pneumophila serogroup 1 (strain Paris) showed that 60% of mice immunized with rFLA survived in a 10-day follow-up survey. These results show that rFLA fromL. pneumophila can elicit strong innate and adaptive immune responses and suggest the possibility of a long-term immunity against lethal challenge withL. pneumophila.J Mol Microbiol Biotechnol 2017;27:110-116
Source: Journal of Molecular Microbiology and Biotechnology - Category: Microbiology Source Type: research