RESUMO
This study was evaluated the ability of DNA vaccine encoding L7/L12 protein of Brucella sp. to induce cellular and humoral immune responses in BALB/c mice and the profile of cytokines and IgG sub classes were determined. Intra muscular vaccination of mice using L7/L12 gene. Three vaccinations at 3 week intervals were performed. Cytokines and IgG subclasses were analyzed 3 week after the last DNA vaccination. Splenic lymphocytes from L7/L12pCDNA3-vaccinated mice produced high levels of IFNy (3100 pg mL(-1)) and low levels of IL-5 (300 pg mL(-1)), 3 weeks post-vaccination. The L7/L12pCDNA3 immunizations elicited high IgG2a isotype response in mice immunized. This antigen also induced IgG1 titers which were slightly lower than the IgG2a titers. Immunological analysis shows the appropriate immune response in BALB/c mice model after vaccination with L7/L12 gene. The high level of IFNgamma and low level of IL-5 in combination with high IgG2a/IgG1 ratio show the activation of Th1 cell response. The lower bacterial cfu from vaccinated mice in comparison with control groups show the efficiency of L7/L12 DNA vaccination in mice model.
