Bagher Moradi - Esfarayen Faculty of medical sciences, Esfarayen, Iran
Zahra Meshkat - Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

Today, Tuberculosis (TB) is an important health problem and DNA vaccines are developed due to their ability in generating a long-lasting immune response and more safety compared to the live vaccines. In the present study, we evaluated a new DNA vaccine encoding fusion hspX-ppe44-esxV antigens, separately, and in combination with BCG in a prime-boost method in mice.Method: Immunogenicity of the recombinant vector containing PPE44-EsxV-HspX fusion product was evaluated in a mouse model. Mice were separated into 5 groups (6 mice per group) and were injected three times intramuscularly in the quadriceps muscles with 100µg of pDNA at 2-week intervals. Three weeks after the last immunization, mice were sacrificed and their spleen was extracted aseptically. Splenic cell cultures were exposed to the purified PPE44-EsxV-HspX fusion protein product Cell culture supernatants were harvested and the concentration of IFN-γ, IL-12, IL-4 and TGF-β Cytokines were measured by ELISA kits.Results: After cytokine assay, the concentrations of INF-γ and IL-12 in the cell culture of spleen cells were significantly increased (799.11±135.51 pg/ml and 92.88±19.50 pg/ml, respectively, compared to the control group (P <0.001) Conclusion:DNA vaccine encoding HspX-PPE44-EsxV fusion antigen of Mycobacterium tuberculosis was produced successfully in the previous study and it was evaluated in the present study. The results of cytokine production in spleen cell cultures showed that this DNA vaccine can stimulate cellular immune responses that can be used as a vaccine candidate in the production of new and effective vaccines against TB.

Mycobacterium tuberculosis, Hsp, PPD protein, BCG vaccine, DNA vaccines