Flagellin expressed by live Salmonella vaccine strains induces distinctantibody responses following delivery via systemic or mucosalimmunization routes

ABSTRACT

Salmonella flagellin, expressed as flagella in live attenuated vaccine strains, elicits distinct systemic (IgG) and secreted (IgA) antibodyresponses in mice following delivery via mucosal (nasal/oral) or parenteral (intraperitoneal (i.p.)) immunization routes. Reduced flagellinspecificantibodies were detected either systemically or locally following delivery of flagellated derivatives of aroA Salmonella entericaserovar Dublin SL1438 via the nasal route, the most effective mucosal site for activation of immune responses in mice. In contrast, flagellinrepresents the most potent Salmonella antigen for the generation of specific serum antibody (IgG) responses following i.p. inoculations. Thedistinct immunogenic properties of Salmonella flagellin could not be ascribed to deficient colonization, reduced invasive ability or loss of theflagellin expression by the flagellated vaccine strains.