Immunization of mice with recombinant protein CobB or AsnC confers protection against Brucella abortus infection

PLoS One. 2012;7(2):e29552. doi: 10.1371/journal.pone.0029552. Epub 2012 Feb 24.

Abstract

Due to drawbacks of live attenuated vaccines, much more attention has been focused on screening of Brucella protective antigens as subunit vaccine candidates. Brucella is a facultative intracellular bacterium and cell mediated immunity plays essential roles for protection against Brucella infection. Identification of Brucella antigens that present T-cell epitopes to the host could enable development of such vaccines. In this study, 45 proven or putative pathogenesis-associated factors of Brucella were selected according to currently available data. After expressed and purified, 35 proteins were qualified for analysis of their abilities to stimulate T-cell responses in vitro. Then, an in vitro gamma interferon (IFN-γ) assay was used to identify potential T-cell antigens from B. abortus. In total, 7 individual proteins that stimulated strong IFN-γ responses in splenocytes from mice immunized with B. abortus live vaccine S19 were identified. The protective efficiencies of these 7 recombinant proteins were further evaluated. Mice given BAB1_1316 (CobB) or BAB1_1688 (AsnC) plus adjuvant could provide protection against virulent B. abortus infection, similarly with the known protective antigen Cu-Zn SOD and the license vaccine S19. In addition, CobB and AsnC could induce strong antibodies responses in BALB/c mice. Altogether, the present study showed that CobB or AsnC protein could be useful antigen candidates for the development of subunit vaccines against brucellosis with adequate immunogenicity and protection efficacy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial / immunology
  • Brucella Vaccine / immunology
  • Brucella abortus / metabolism*
  • Brucellosis / immunology
  • Brucellosis / prevention & control*
  • Escherichia coli Proteins / metabolism*
  • Female
  • Immune System
  • Immunization
  • Interferon-gamma / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Recombinant Proteins / metabolism
  • Sirtuins / metabolism*
  • Spleen / cytology
  • Superoxide Dismutase / metabolism
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / microbiology
  • Trans-Activators / metabolism*

Substances

  • Antigens, Bacterial
  • AsnC protein, E coli
  • Brucella Vaccine
  • Escherichia coli Proteins
  • Recombinant Proteins
  • Trans-Activators
  • Interferon-gamma
  • Superoxide Dismutase
  • Sirtuins
  • cobB protein, E Coli