Elucidating_novel_transcriptional_and_metabolomic_death_signatures_in_TB. Elucidating_novel_transcriptional_and_metabolomic_death_signatures_in_TB

The single greatest impediment to tuberculosis control is the inability to sterilize cultures of Mycobacterium tuberculosis. Short course chemotherapy for drug-sensitive M. tuberculosis is six months long. Short is paradoxical when you consider that the addition of any bactericidal drug will kill 99-99.9% of M. tuberculosis cells in 3-4 days, the remaining 0.1-1% of cells are M. tuberculosis persisters. These persisters are cells that are phenotypically drug tolerant but not genetically drug resistant. This phenotype of persistence evolved long before M. tuberculosis encountered modern chemotherapy but was a result of a stress response to environmental conditions or immune killing effectors. We have begun to characterize this phenotypic property of persistence with the identification of mutant’s that are unable to persist. Specifically, we have demonstrated that the deletion of 1 of the 12 non-essential sigma factors (namely SigE) is uniquely sterilized with the addition of the drug isoniazid. In addition, we have demonstrated that when M. tuberculosis cells are starved for methionine or arginine the cultures are rapidly sterilized. As an alternative approach, we have demonstrated that the addition of cysteine or vitamin C to isoniazid treated cells also rapidly sterilizes the M. tuberculosis culture. By employing a new type of dual reporter mycobacteriophage, we have been able to visualize persisters in culture for the first time. Moreover, we have used this dual reporter mycobacteriophage to prove that these different sterilization phenotypes are different. We propose to use a combination of comprehensive transcriptomic analysis using RNAseq of these various sterilizing methodologies to discover the important physiological signatures of sterilization. Such knowledge should lead to the development of new chemotherapeutic and immunotherapeutic strategies to sterilize cultures of M. tuberculosis and thus improve Tuberculosis control. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/