We developed a novel therapeutic DNA TB vaccine that promotes immune responses to the stringent response protein RelMtb, which are further enhanced by fusion with a chemokine gene, Macrophage Inflammatory Protein-3 alpha (MIP-3α), that targets relMtb to immature dendritic cells (DCs). Our data show that an intranasal (IN) or intramuscular (IM) DNA vaccine expressing MIP-3α/relMtb (“fusion” vaccine) demonstrated greater adjunctive therapeutic efficacy when combined with the first-line TB treatment in Mtb-infected mice as compared to IM vaccination with relMtb alone (“non-fusion” vaccine). This proposal will dissect the mechanisms of this novel therapeutic strategy, specifically with IN administration which had the highest efficacy. We will also test whether this strategy is likely to perform in PLWHA, analyzing whether RelMtb-specific immune responses in PLWHA can predict therapeutic TB outcomes. The proposed studies will uncover critical details of the mechanism of a novel therapeutic vaccination approach against TB with important implications in PLWHA and help the PI to gain significant expertise in TB/HIV immunology.