Polyethylenimine modified nanoparticle adjuvant increases therapeutic efficacy of DNA vaccine Ag85A-ESAT-6-IL-21 in mice infected with Mycobacterium tuberculosis

Despite considerable research efforts, the treatment of tuberculosis (TB) remains to be a great challenge in the requirement of prolonged therapy with multiple high-dose drugs and associated side effects. As such, the development of an effective vaccine to treat TB may be feasible strategy. The aim of this study was to investigate the possibility of polyethylenimine (PEI) modified nanoparticle adjuvant increases therapeutic efficacy of DNA vaccine Ag85A-ESAT-6-IL-21 in mice that were aerosol infection with the standard virulent M. tuberculosis strain H37Rv. The therapeutic effect was observed in the mice after M. tuberculosis infectious mouse model was established. The results indicated that the PEI modified DNA vaccine significantly induced a powerful therapeutic efficacy compared with that of Bacille Calmette-Guérin (BCG) or other immunotherapeutic vaccinations, which was reflected in decreasing the M. tuberculosis numbers and pathological damage in lungs, and increasing the mouse weight gain. The effective mechanism was closely related with a strong immune response induced by the DNA vaccine in the mice. The findings provide further approaches for PEI modified DNA vaccine Ag85A-ESAT-6-IL-21 as a potential therapeutic vaccine to fight against TB.