Assessment of recombinant plasmid expressing fusion antigen Ag85B-Rv3425 in management of acute tuberculosis infection in mice.

The emergence of drug-resistant tuberculosis (TB) and HIV-TB co-infection fuels an urgent need to develop novel therapeutic approaches, including therapeutic vaccines. Therapeutic vaccines have been proven to be a good strategy by inducing antigen specific immune responses against TB infection. In the present study, a recombinant plasmid based on lentiviral vector expressing fusion antigen Ag85B-Rv3425 (A3), and was constructed the immunogenicity and treatment effects in TB mice were assessed. The results showed that A3 delivered by the plasmid could be expressed appropriately and induced higher production of tumor necrosis factor-α and interleukin-2 compared with A3 recombinant protein in mice. Moreover, the recombinant plasmid expressing A3 confered resistance to acute TB infection in mice, characterized by a reduction in the bacterial load in the lungs and spleen, as well as attenuated TB lesions in lung tissues. These results implicated that the recombinant plasmid based on lentiviral vector expressing A3 is a potent and promising therapeutic agent to treat acute TB infection.