Mycobacterium tuberculosis (Mtb) remains a global health problem worsened by the increasing prevalence of multi-drug (MDR) and extensively drug resistant (XDR) strains and co-infection with HIV. Recently, the persistence phenotype of Mtb, which allows the microbe to effectively evade the host immune response and 'persist'amid long-term drug treatment, has garnered much attention as being the single biggest impediment to tuberculosis (TB) control. Persistence makes Mtb an extremely effective pathogen and difficult to control. The theme of this proposal for the last 25 years has been to isolate mutants of Mtb to probe the biological mechanisms associated with TB pathogenesis and drug resistance. We propose to extend this theme by genetically analyzing mechanisms of persistence. Based on our recent discovery that Mtb can induce DNA nets in human macrophages, we postulate that persistence in vivo can be the result of extracellular Mtb growing in pellicles or biofilms in vivo. We plan to test this hypothesis with mutant Mtb cells and a novel Persister reporter Phage (PRP) that we have developed to identify persister Mtb cells. We have isolated novel classes of mutants Mtb that fail to persist in macrophages, and we plan to explore their biology using a combination of transcriptomic and metabolomic analyses. Lastly, using a saturating transposon mutagenesis method, we have discovered a novel succinate dehydrogenate activity required for resisting killing by the combination of Isoniazid and Rifampicin. Preliminary data suggests that this mutation causes an inability to regulate respiration which converges with our recent discovery that Vitamin C can kill persister Mtb cells. We intend to further expand these concepts and test their relevance in mouse models. Knowledge of the biological mechanisms of persistence should lead to better diagnostics, better immunotherapies and better chemotherapies.
Tuberculosis (TB) remains a global health threat, particularly with the recent emergence of strains that are resistant to all 10 anti-TB drugs. Mycobacterium tuberculosis (Mtb), the causative agent of TB, has evolved mechanisms to persist - a physiological response to resist killing. This proposal will use a multidisciplinary proposal combines mycobacterial genetics, transcriptomics, metabolomics and mouse models to study the persistence phenotype of Mtb. Knowledge gained should lead to improved diagnostics, more effective vaccines, and better chemotherapies.
|Cook, Gregory M; Hards, Kiel; Vilchèze, Catherine et al. (2014) Energetics of Respiration and Oxidative Phosphorylation in Mycobacteria. Microbiol Spectr 2:|
|Sixsmith, Jaimie D; Panas, Michael W; Lee, Sunhee et al. (2014) Recombinant Mycobacterium bovis bacillus Calmette-Guérin vectors prime for strong cellular responses to simian immunodeficiency virus gag in rhesus macaques. Clin Vaccine Immunol 21:1385-95|
|Stec, Jozef; Vilchèze, Catherine; Lun, Shichun et al. (2014) Biological evaluation of potent triclosan-derived inhibitors of the enoyl-acyl carrier protein reductase InhA in drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis. ChemMedChem 9:2528-37|
|Hartman, Travis; Weinrick, Brian; Vilchèze, Catherine et al. (2014) Succinate dehydrogenase is the regulator of respiration in Mycobacterium tuberculosis. PLoS Pathog 10:e1004510|
|Wong, Ka-Wing; Jacobs Jr, Williams R (2013) Mycobacterium tuberculosis exploits human interferon ? to stimulate macrophage extracellular trap formation and necrosis. J Infect Dis 208:109-19|
|Vilcheze, Catherine; Hartman, Travis; Weinrick, Brian et al. (2013) Mycobacterium tuberculosis is extraordinarily sensitive to killing by a vitamin C-induced Fenton reaction. Nat Commun 4:1881|
|Kozakiewicz, Lee; Chen, Yong; Xu, Jiayong et al. (2013) B cells regulate neutrophilia during Mycobacterium tuberculosis infection and BCG vaccination by modulating the interleukin-17 response. PLoS Pathog 9:e1003472|
|Vilcheze, Catherine; Baughn, Anthony D; Tufariello, JoAnn et al. (2011) Novel inhibitors of InhA efficiently kill Mycobacterium tuberculosis under aerobic and anaerobic conditions. Antimicrob Agents Chemother 55:3889-98|
|Waters, W Ray; Palmer, Mitchell V; Nonnecke, Brian J et al. (2009) Efficacy and immunogenicity of Mycobacterium bovis DeltaRD1 against aerosol M. bovis infection in neonatal calves. Vaccine 27:1201-9|
|Banaiee, Niaz; January, Vanessa; Barthus, Charmaine et al. (2008) Evaluation of a semi-automated reporter phage assay for susceptibility testing of Mycobacterium tuberculosis isolates in South Africa. Tuberculosis (Edinb) 88:64-8|
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