Evaluation of the efficacy of outer membrane protein 31 vaccine formulations for protection against Brucella canis in Balb/c mice

CLAUSSE M., DÍAZ A. G., IBAÑEZ A. E., CASSATARO J., GIAMBARTOLOMEI G. H., ESTEIN S. M.

CLINICAL AND VACCINE IMMUNOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2014

1556-6811

Canine brucellosis is an infectious disease caused by the Gram-negative bacterium Brucella canis. Unlike conventional controlprograms for other species of the genus Brucella, currently there is no vaccine available against canine brucellosis, and preventivemeasures are simply diagnosis and isolation of infected dogs. New approaches are therefore needed to develop an effectiveand safe immunization strategy against this zoonotic pathogen. In this study, BALB/c mice were subcutaneously immunizedwith the following: (i) the recombinant Brucella Omp31 antigen formulated in different adjuvants (incomplete Freund adjuvant,aluminum hydroxide, Quil A, and Montanide IMS 3012 VGPR), (ii) plasmid pCIOmp31, or (iii) pCIOmp31 plasmid, followed byboosting with recombinant Omp31 (rOmp31). The immune response and the protective efficacy against B. canis infection werecharacterized. The different strategies induced a strong immunoglobulin G (IgG) response. Furthermore, spleen cells fromrOmp31-immunized mice produced gamma interferon and interleukin-4 (IL-4) after in vitro stimulation with rOmp31, indicatingthe induction of a mixed Th1-Th2 response. Recombinant Omp31 administered with different adjuvants as well as theprime-boost strategy conferred protection against B. canis. In conclusion, our results suggest that Omp31 could be a useful candidatefor the development of a subcellular vaccine against B. canis infection.