Co-immunization with DNA vaccines encoding yidR and IL-17 augments host immune response against infection in mouse model.

is an important gram-negative bacterium that causes severe respiratory and healthcare-associated infections. Although antibiotic therapy is applied to treat severe infections caused by , drug-resistant isolates pose a huge challenge to clinical practices owing to adverse reactions and the mismanagement of antibiotics. Several studies have attempted to develop vaccines against , but there are no licensed vaccines available for the control of infection. In the current study, we constructed a novel DNA vaccine, pVAX1-YidR, which encodes a highly conserved virulence factor YidR and a recombinant expression plasmid pVAX1-IL-17 encoding Interleukin-17 (IL-17) as a molecular adjuvant. Adaptive immune responses were assessed in immunized mice to compare the immunogenicity of the different vaccine schemes. The results showed that the targeted antigen gene was expressed in HEK293T cells using an immunofluorescence assay. Mice immunized with pVAX1-YidR elicited a high level of antibodies, induced strong cellular immune responses, and protected mice from challenge. Notably, co-immunization with pVAX1-YidR and pVAX1-IL-17 significantly augmented host adaptive immune responses and provided better protection against infections in vaccinated mice. Our study demonstrates that combined DNA vaccines and molecular adjuvants is a promising strategy to develop efficacious antibacterial vaccines against infections.