Efficient tuberculosis treatment in mice using chemotherapy and immunotherapy with the combined DNA vaccine encoding...

Although most cases of tuberculosis (TB) can be cured with antibiotics, relapse is common if patients do not continue chemotherapy for at least 6 months. Thus, improved therapeutic strategies are urgently needed. We previously found that the combined DNA vaccine encoding the Mycobacterium tuberculosis proteins Ag85B, MPT-64 and MPT-83 protected mice from TB following H37Rv challenge and considered whether this combined DNA vaccine has a therapeutic effect. In the present work, we demonstrate that boosting the efficiency of the immune system with the combined DNA vaccine may be a valuable adjunct to shorten the duration of antibacterial chemotherapy. Mice treated with the combined DNA vaccine along with isoniazid and pyrazinamide showed significantly higher interferon-gamma responses to a mixture of the three specific antigens (P<0.001), which were accompanied by a significant reduction in colony-forming unit in H37Rv-infected animals 3-5 months after treatment (P<0.001). These results suggest that the combined DNA vaccine along with conventional TB chemotherapy has strong potential for TB immunotherapy and may provide new alternatives to control the disease.