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The development of a tuberculosis (TB) vaccine that induces sterilizing immunity to Mycobacterium tuberculosis infection has been elusive. Absence of sterilizing immunity induced by TB vaccines may be due to delayed activation of mucosal dendritic cells (DCs), and subsequent delay in antigen presentation and activation of vaccine-induced CD4+ T-cell responses. Here we show that pulmonary delivery of activated M. tuberculosis antigen-primed DCs into vaccinated mice, at the time of M. tuberculosis exposure, can overcome the delay in accumulation of vaccine-induced CD4+ T-cell responses. In addition, activating endogenous host CD103+ DCs and the CD40–CD40L pathway can similarly induce rapid accumulation of vaccine-induced lung CD4+ T-cell responses and limit early M. tuberculosis growth. Thus, our study provides proof of concept that targeting mucosal DCs can accelerate vaccine-induced T-cell responses on M. tuberculosis infection, and provide insights to overcome bottlenecks in TB vaccine efficacy.

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One quarter of the world’s population is infected with Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). Although most infected individuals successfully control or clear the infection, some individuals will progress to TB disease. Immune correlates identified using animal models are not always effectively translated to human TB, thus resulting in a slow pace of translational discoveries from animal models to human TB for many platforms including vaccines, therapeutics, biomarkers, and diagnostic discovery. Therefore, it is critical to improve our poor understanding of immune correlates of disease and protection that are shared across animal TB models and human TB. In this study, we have provided an in-depth identification of the conserved and diversified gene/immune pathways in TB models of nonhuman primate and diversity outbred mouse and human TB. Our results show that prominent differentially expressed genes/pathways induced during TB disease progression are conserved in genetically diverse mice, macaques, and humans. In addition, using gene-deficient inbred mouse models, we have addressed the functional role of individual genes comprising the gene signature of disease progression seen in humans with Mtb infection. We show that genes representing specific immune pathways can be protective, detrimental, or redundant in controlling Mtb infection and translate into identifying immune pathways that mediate TB immunopathology in humans. Together, our cross-species findings provide insights into modeling TB disease and the immunological basis of TB disease progression.