In an era of HIV, multidrug resistant tuberculosis, and bioterrorism, the need for novel chemotherapeutic agents against Mycobactedum tuberculosis has never been greater. The durable success of M. tuberculosis as a pathogen is largely attributable to its ability to evade a sterilizing response from the innate immune system through the evolution of mechanisms that either defuse or repair noxious insults. A detailed understanding of the antimicrobial mechanisms used by the innate immune system, therefore, may reveal novel chemotherapeutic targets. Macrophage-associated nitric oxide and reactive nitrogen intermediates (NO/RNI) are a critical component of this innate immune response. Surprisingly, no specific protein targets of NO/RNI-mediated damage have been identified. The focus of the proposed work is to define target of NO/RNI-mediated protein-S-nitrosylation and novel effects of NO/RNI on biotinylated proteins of M. tuberculosis. Accumulating evidence supports an emerging role for protein-S-nitrosylation as an important mediator of the antimicrobial effects of NO/RNI. The obligatory role of biotin in lipid biosynthesis and the importance of lipids in the virulence of M. tuberculosis suggest a similarly important antimicrobial role for the NO/RNI-dependent effects discovered in our preliminary studies. We propose to evaluate the importance of these NO/RNI-dependent effects using the 'biotin-switch' method to identify, at the proteomic level, Snitrosylated proteins; biotin-based affinity chemistries to study NO-induced alterations in biotinylated proteins; and a combination of enzyme assays, chemical inhibitor studies and macrophage infection experiments using site-directed mutagenesis and targeted gene knockouts to assess the functional importance of these targets. The identification of bona fide targets of NOIRNI-mediated damage in M. tuberculosis offers the promise of developing novel antitubercular agents that augment or mimic the natural immune response to infection with M. tuberculosis while circumventing NO/RNI-specific defenses.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08AI061393-03
Application #
7057780
Study Section
Microbiology and Infectious Diseases B Subcommittee (MID)
Program Officer
Jacobs, Gail G
Project Start
2004-07-01
Project End
2008-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
3
Fiscal Year
2006
Total Cost
$125,280
Indirect Cost
Name
Weill Medical College of Cornell University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
060217502
City
New York
State
NY
Country
United States
Zip Code
10065
Gardiner, David F; Rhee, Kyu Y (2006) An unusual cause of ST segment elevation. Brugada syndrome. Clin Infect Dis 42:826-7, 885-6