009) and CD8+ (P = 0.02) cells after booster vaccination than after prime vaccination. The concentration of IFN-γ, a cytokine which is one of the main indicators of the formation of Th1 and a cytotoxic cellular immune response, was also determined. As shown in Fig. 2, significant (P < 0.0001) accumulation of IFN-γ after stimulation with Brucella L7/L12 and Omp16 proteins was observed in the samples from the animals vaccinated with the viral constructs vaccine formulation only, as well as its combination with Montanide Gel01, or the B. abortus S19 vaccine
as compared to the control samples (without stimulation). Significant accumulation of IFN-γ was not observed in the samples from the group of animals vaccinated with Flu-L7/L12-Omp16-chitosan. CDK inhibitor It should be noted that the highest levels of IFN-γ accumulation after stimulation with Brucella antigens was observed in the samples from animals Autophagy inhibitor in vivo vaccinated with Flu-L7/L12-Omp16-MontanideGel01; the IFN-γ levels for this group were significantly higher (P = 0.01 or P = 0.0003) than the other experimental groups (28 days after the prime vaccination) and even slightly
superior (P = 0.12 or P = 0.22) to that of the positive control group vaccinated with B. abortus S19. Booster immunization did not significantly (P = 0.09 to P = 0.99) increase the concentration of IFN-γ in the samples from the animals in the experimental groups. As shown in Fig. 3, the highest level of protection was achieved with Flu-L7/L12-Omp16-MontanideGel01; the effectiveness of vaccination and index of infection for this group were 100% and 0, respectively. Good however results were also obtained with Flu-L7/L12-Omp16, which had a similar effectiveness of vaccination (60%), index of infection and number of cultured Brucella (P = 0.99 or P > 0.99) to the group vaccinated with the B. abortus S19 vaccine. The lowest effectiveness of
vaccination (40%) was observed for Flu-L7/L12-Omp16-chitosan. Despite this, the number of Brucella cultured from the lymph nodes and index of infection in this group was significantly lower (P = 0.02 or P = 0.007) than that of the negative control group (PBS), and not significantly different to the other experimental groups (from P = 0.29 to P = 0.98) or the positive control group (P = 0.62 or P = 0.92) groups. After challenge with B. abortus 544, the body temperature of the animals in the experimental groups remained within the normal range (37.5–39.5 °C) during the entire period of observation (30 days), while the body temperature of the animals in the negative and positive control groups increased to 40.0 °C on days 1–3 and day 2 post-challenge, respectively. The present work is a continuation of a series of studies aimed at developing an effective vaccine against B. abortus. As previously stated, a number of candidate vaccines against B. abortus have been prepared to date, most of which are DNA vaccines and live recombinant vaccines.