Inducible Gene Regulation in Mycobacteria


Principal Investigator: JESSICA CHUANG SEELIGER
Abstract: DESCRIPTION (provided by applicant): Tuberculosis (TB) is the second leading cause of death among communicable diseases worldwide. The current front-line TB drug isoniazid acts by inhibiting the biosynthesis of an Mtb outer membrane lipid, mycolic acid, underscoring the importance of the outer membrane in virulence and survival. However, widespread resistance to isoniazid and other front-line therapies requires the development of new drugs to combat multidrug- and extensively drug-resistant organisms (MDR/XDR-TB). Novel therapies that inhibit multiple targets by combining two or more agents are highly desirable to increase the rapidity and efficacy of treatment and slow the emergence of drug resistance. Therefore, there is an urgent need to identify the effects of repressing two genes simultaneously. The long-term goals are to elucidate (1) the mechanisms of outer membrane biogenesis and (2) the synergism between these pathways in promoting Mtb virulence and survival. The objective of this application is to facilitate these goals through the development of novel gene regulation systems for mycobacteria. The overall strategy is to optimize riboswitches for efficient, inducible gene expression and repression. The rationale for the proposed research is that inducible gene regulation tools based on riboswitches will enable, for the first time, the independent and simultaneous experimental control of two genes both in vitro and in vivo. Thus, the following specific aims are proposed: (1) To optimize inducible riboswitches to turn gene expression on or off;(2) to demonstrate riboswitch regulation of endogenous mycobacterial genes;and (3) to determine an appropriate dosing regimen for the effector molecule in mice. Riboswitches that respond to different effector molecules have been validated in in vitro culture and macrophage infection models in the applicant's laboratory. The approach is to identify optimal riboswitches by screening libraries of randomized sequence variants. The research proposed in this application is innovative because it departs from the status quo via the application of riboswitches to mycobacterial gene regulation and will overcome a current technical hurdle in the systematic evaluation of dual knockout phenotypes. This contribution is significant because the elucidation of dual knockout phenotypes, whether synthetic lethal or suppressive, will help create maps of metabolic and signaling pathways and their interactions, and also facilitate the functional assignment of the hundreds of Mtb genes of unknown function.
Funding Period: 2013-08-15 - 2015-07-31
more information: NIH RePORT

Detail Information

Research Grants30

  1. Intra Cavitary Pharmacokinetics and Drug Resistance in Pulmonary Tuberculosis
    RUSSELL RYAN KEMPKER; Fiscal Year: 2013
    ..The IDPL is a national reference laboratory for anti-mycobacterial drug concentrations and has extensive expertise in performing microdialysis. ..
  2. Screening for inhibitors of M. tuberculosis persistence-related lipid metabolism
    Robert B Abramovitch; Fiscal Year: 2013
    ..The goa of this proposal is to identify a lead compound that is suitable for further optimization and that specifically targets the chronic stage of tuberculosis infection. ..
  3. Molecular Analysis of Tuberculosis Immunity
    WILLIAM ROBERT JACOBS; Fiscal Year: 2013
    ..smegmatis ?ike mutant containing a set of M. tuberculosis genes (named IKEPLUS) elicits a bactericidal immunity against M. tuberculosis. Heterologous prime and boosts with ILEPLUS and attenuated M. tuberculosis will be explored. ..
  4. Toward a Universal Influenza Virus Vaccine
    Peter Palese; Fiscal Year: 2013
    ..These epitopes will then be used to guide the design of vaccine constructs which induce cross-protective immune responses against many different influenza virus variants. ..
  5. Primary Immune Deficiency Treatment Consortium
    Morton Cowan; Fiscal Year: 2013
    ..These studies will resolve critical questions concerning HCT for these disorders and form the basis for future prospective clinical trials. ..
  6. Gyrase B Inhibitors for Mycobacterium Tuberculosis
    Peter B Madrid; Fiscal Year: 2013
    ..The development of a shorter, more effective treatment regimen will increase patient compliance and thereby slow down the emergence of drug resistance and protect vulnerable populations worldwide. ..
  7. Carbon monoxide resistance in Mycobacterium tuberculosis pathogenesis
    MICHAEL SHILOH; Fiscal Year: 2013
    ..The proposed work will extend the current knowledge on M. tuberculosis's antimicrobial resistance mechanisms and reveal a novel microbial survival strategy. ..
  8. Disrupting Biofilm Formation to Improve TB Drug Treatment
    Randall J Basaraba; Fiscal Year: 2013
    ..Finally, we will reveal the mechanisms of action of our current anti-biofilm compounds and the identity of other druggable targets unique to drug-tolerant Mtb. ..
  9. Transcriptional regulation of lipid homeostasis in mycobacteria
    Hugo Gramajo; Fiscal Year: 2013
  10. Construction and evaluation of next-generation reporter mycobacteriophages
    Graham F Hatfull; Fiscal Year: 2013
    ..This research will be primarily done in Argentina at University of Buenos Aires in collaboration with Dr. Mariana Piuri as an extension of NIH Grant AI064494 (7/1/06 - 6/30/11). ..
  11. Host-Responses to Mycobacterium Infection in Zebrafish
    Lalita Ramakrishnan; Fiscal Year: 2013
  12. Developing High-Throughput Assays for M. tuberculosis Tat Pathway Inhibitors
    WILLIAM PERRY JANZEN; Fiscal Year: 2013
    ..Upon completion of this work, we intend to apply for Fast Track entry of our screening campaign into the NIH Molecular Libraries Probe Production Centers Network. ..
  13. A Kit for Rapid AST of Mycobacterium tuberculosis from Clinical Samples
    MATTHEW CHARLES MULVEY; Fiscal Year: 2013
    ..We have invented a new technology with promise to accomplish this goal and are working to bring it to market. ..
  14. Pacific NorthWest Regional Center of Excellence (PNWRCE)
    Jay A Nelson; Fiscal Year: 2013
    ..pseudomallei host pathogen response during both the septicemic as well as the intracellular phases of the disease. ..
  15. Southeast Regional Centers of Excellence for Biodefense &Emerging Infectious Di
    Philip Frederick Sparling; Fiscal Year: 2013
    ..SERCEB brings new investigators to the biodefense effort through a combination of educational programs, support of innovative new projects, and the synergistic interactions among its world-class investigators. ..
  16. High throughput assays to detect inhibition of a key M. tuberculosis protease
    Tanya Parish; Fiscal Year: 2013
    ..The significance of our proposal is that it has a dual outcome;regeneration of the early drug pipeline by enabling HTS and stimulation of basic biological studies by providing chemical probes. ..
  17. Northeast Biodefense Center
    W Ian Lipkin; Fiscal Year: 2013
    ..As a Center based in a School of Public Health and a State Department of Health, the NBC has a firm commitment to and practical understanding of Emergency Preparedness. ..
  18. Folate Metabolism in Mycobacterium tuberculosis Revisited: A Potential Drug Targe
    Liem Duy Nguyen; Fiscal Year: 2013
  19. Targeting MraY: Synthesis and Validation of MraY Inhibitors
    Michio Kurosu; Fiscal Year: 2013
    ..Clinical responses of MDR- TB patient to currently available drugs have been poor, and in some cases there is no response at all. The long term goal of this grant submission is to develop new drug leads for MDR-TB. ..
  20. Pacific Southwest RCE for Biodefense &Emerging Infectious Diseases Research
    Alan G Barbour; Fiscal Year: 2013
    ..abstract_text> ..
  21. Rocky Mountain Regional Center of Excellence or Biodefense and Emerging Infectiou
    John T Belisle; Fiscal Year: 2013
    ..abstract_text> ..
  22. A Community Mycobacterial Systems Resource
    JOSEPH THOMAS WADE; Fiscal Year: 2013
    ..In summary, the MSR will provide unprecedented insight into mycobacterial biology and will serve as a launch pad for future studies by researchers spanning the mycobacterial community. ..