Evaluation of immune responses in mice and sheep inoculated with a live attenuated Brucella melitensis REV1 vaccine produced in bioreactor

In this study, we produced REV1 vaccine with a protocol, based on the use of liquid medium in a bioreactor, that resulted efficient, safe, relatively fast, and cost-effective. The live attenuated vaccine produced was tested in mice and sheep to investigate its immunogenicity and efficacy. Seventy-two female BALB/c mice were obtained and subdivided in 2 groups, one was stimulated with 1 × 106 colony-forming units (CFUs) of B. melitensis while the other with physiological solution alone and acting as control group. Furthermore, 25 sheep were subdivided into 5 groups: four were inoculated with a B. melitensis dose, ranging from 0.6 × 109 and 3.2 × 109 CFUs and the other was the control group. In addition, a serological diagnosis was performed for sheep by rapid serum agglutination and the complement-fixation test. Immunocompetent cells from both experiment were collected at different times post vaccination and immunostained to evaluate innate and adaptive-immune responses. In mice flow cytometry was used to detect macrophages, T lymphocytes, dendritic cells, memory cells, naïve cells, natural killer cells, major histocompatibility complex type II, B lymphocytes, regulatory T lymphocytes, T helper lymphocytes, cytotoxic T lymphocytes and recently activated CD4+ and CD8+ lymphocytes. In sheep, macrophages, T helper cells, cytotoxic T lymphocytes, regulatory T lymphocytes, dendritic cells, memory cells and naïve lymphocytes, by the same method, were analyzed. The r...
Source: Veterinary Immunology and Immunopathology - Category: Veterinary Research Source Type: research