Protective Immunity Against Lung Infection Induced by a DNA Plasmid Vaccine Carrying Gene Inhibits Dissemination in BALB/c Mice

(), a zoonotic pathogen, poses a potential threat to public health security and the development of animal husbandry. Vaccine-based preventative measures for infectious diseases have a promising landscape. DNA vaccines, with many advantages, have become one of the dominant candidate strategies in preventing and controlling the chlamydial infection. Our previous study showed that CPSIT_p7 protein is an effective candidate for a vaccine against . Thus, this study evaluated the protective immunity of pcDNA3.1(+)/CPSIT_p7 against infection in BALB/c mice. We found that pcDNA3.1(+)/CPSIT_p7 can induce strong humoral and cellular immune responses. The IFN-γ and IL-6 levels in the infected lungs of mice immunized with pcDNA3.1(+)/CPSIT_p7 reduced substantially. In addition, the pcDNA3.1(+)/CPSIT_p7 vaccine diminished pulmonary pathological lesions and reduced the load in the lungs of infected mice. It is worth noting that pcDNA3.1(+)/CPSIT_p7 suppressed dissemination in BALB/c mice. In a word, these results demonstrate that the pcDNA3.1(+)/CPSIT_p7 DNA vaccine has good immunogenicity and immunity protection effectiveness against infection in BALB/c mice, especially pulmonary infection, and provides essential practical experience and insights for the development of a DNA vaccine against chlamydial infection.