FNBPA (pValac:) Induces Cellular and Humoral Immune Responses After Oral Immunization of Mice.

The development of a new vaccine strategy against tuberculosis is urgently needed and has been greatly encouraged by the scientific community worldwide. In this work, we constructed a lactococcal DNA vaccine based on the fusion of two antigens, ESAT-6 and Ag85A, and examined its immunogenicity. The coding sequences of the and genes were fused and cloned into the eukaryotic expression pValac vector, and the functionality of the vector was confirmed . Then, FnBPA (pValac:) was obtained and used for oral immunization of mice. This strain induced significant increases in IFN-γ, TNF-α, and IL-17 cytokines in stimulated splenocyte cultures, and significant production of antigen-specific sIgA was observed in the colonic tissues of immunized mice. We demonstrated that FnBPA (pValac:) generated a cellular and humoral immune response after oral immunization of mice. The strategy developed in this work may represent an interesting DNA mucosal vaccine candidate against tuberculosis, using the fusion of two highly immunogenic antigens delivered by safe lactic acid bacteria.