Enhancement of host immune responses by oral vaccination to Salmonella enterica serovar Typhimurium harboring both FliC and FljB flagella

PLoS One. 2013 Sep 17;8(9):e74850. doi: 10.1371/journal.pone.0074850. eCollection 2013.

Abstract

Flagellin, the structural component of the flagellar filament in various motile bacteria, can contribute to the activation of NF-κB and proinflammatory cytokine expression during the innate immune response in host cells. Thus, flagellin proteins represent a particularly attractive target for the development of vaccine candidates. In this study, we investigated the immune response by increasing the flagella number in the iacP mutant strain and the adjuvant activity of the flagellin component FljB of Salmonella enterica serovar Typhimurium. We found that the iacP mutant strain expresses two flagellin proteins (FliC and FljB), which result in increased NF-κB-dependent gene expression in bone marrow derived macrophages. Using an oral immunization mouse model, we observed that the administration of a live attenuated S. typhimurium BRD509 strain expressing the FliC and FljB flagellins induced significantly enhanced flagellin-specific IgG responses in the systemic compartment. The mice immunized with the recombinant attenuated S. typhimurium strain that has two types of flagella were protected from lethal challenge with the Salmonella SL1344 strain. These results indicate that overexpression of flagella in the iacP mutant strain enhance the induction of an antigen-specific immune responses in macrophage cell, and both the FliC and FljB flagellar filament proteins-producing S. typhimurium can induce protective immune responses against salmonellosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology*
  • Cell Line
  • Cytokines / metabolism
  • Disease Models, Animal
  • Enzyme Activation
  • Female
  • Flagella / immunology*
  • Flagella / metabolism
  • Flagellin / genetics
  • Flagellin / immunology*
  • Gene Expression
  • Inflammation Mediators / metabolism
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Mutation
  • NF-kappa B / metabolism
  • Protein Transport
  • Salmonella Infections / immunology*
  • Salmonella Infections / metabolism
  • Salmonella Infections / prevention & control
  • Salmonella Vaccines / administration & dosage
  • Salmonella Vaccines / immunology*
  • Salmonella typhimurium / genetics
  • Salmonella typhimurium / immunology*
  • Salmonella typhimurium / metabolism
  • Vaccination

Substances

  • Antigens, Bacterial
  • Cytokines
  • FljB protein, Salmonella
  • Inflammation Mediators
  • NF-kappa B
  • Salmonella Vaccines
  • Flagellin

Grants and funding

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0012804). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.