Countermeasures for bioterrorism typical target the pathogen as opposed to the host. However, pathogens with drug-resistant characteristics are readily produced, either by naturally occurring selection or deliberate engineering by terrorists. We propose a novel countermeasure approach involving design of multi-purpose inhibitors of cellular host factors that pathogens depend on for their virulence. Because these inhibitors are equally effective against both the natural and the re-engineered pathogens, they will be a valuable addition to the existing biodefense armamentarium. We propose to use Anthrax as a well-established model of a Class A pathogen. Bacillus anthracis is deadly in part because of the toxin it secretes. To become active, Protective Antigen (PA), an essential delivery component of lethal Anthrax Toxin, requires furin-family proteases for proteolytic processing, similar to several additional bacterial virulence factors and viruses, including hemorrhagic fever flaviviruses and avian influenza H5N1 (bird flu). Once inside the cytosol of host cells, the Anthrax Toxin stimulates activation of NALP1, inducing apoptosis. NALP1 is a member of the NLR family, proteins that form complexes known as "inflammasomes," which activate caspase-family proteases. Genetic studies of mice indicate that NALP1 is required for Anthrax Toxin-induced macrophage apoptosis and in vivo susceptibility to lethal disease in the setting of Bacillus anthracis exposure. We propose to generate small-molecule chemical inhibitors of furin-family proteases and NLR-family caspase activators. To this end, we have assembled a multi-disciplinary, collaborative team with expertise in high-throughput chemical library screening, medicinal chemistry, and drug discovery;we have also produced several prototype assays for high throughput screening, with the aim of generating chemical leads against furin- and NALP-family proteins. These leads will be optimized for potency, selectivity, and pharmacological properties, and then tested in rodent models of Anthrax. The resulting chemical inhibitors of furin- and NALP1-family host proteins will provide lead compounds for potential clinical development.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01AI078048-05
Application #
8259775
Study Section
Special Emphasis Panel (ZAI1-TP-M (J1))
Program Officer
Franceschi, Francois J
Project Start
2008-05-01
Project End
2013-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
5
Fiscal Year
2012
Total Cost
$837,768
Indirect Cost
$375,682
Name
Sanford-Burnham Medical Research Institute
Department
Type
DUNS #
020520466
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Gerlic, Motti; Faustin, Benjamin; Postigo, Antonio et al. (2013) Vaccinia virus F1L protein promotes virulence by inhibiting inflammasome activation. Proc Natl Acad Sci U S A 110:7808-13
Askari, Nadav; Correa, Ricardo G; Zhai, Dayong et al. (2012) Expression, purification, and characterization of recombinant NOD1 (NLRC1): A NLR family member. J Biotechnol 157:75-81
D'Osualdo, Andrea; Reed, John C (2012) NLRP1, a regulator of innate immunity associated with vitiligo. Pigment Cell Melanoma Res 25:5-8
Shiryaev, Sergey A; Cheltsov, Anton V; Gawlik, Katarzyna et al. (2011) Virtual ligand screening of the National Cancer Institute (NCI) compound library leads to the allosteric inhibitory scaffolds of the West Nile Virus NS3 proteinase. Assay Drug Dev Technol 9:69-78
Remacle, Albert G; Gawlik, Katarzyna; Golubkov, Vladislav S et al. (2010) Selective and potent furin inhibitors protect cells from anthrax without significant toxicity. Int J Biochem Cell Biol 42:987-95
Cheltsov, Anton V; Aoyagi, Mika; Aleshin, Alexander et al. (2010) Vaccinia virus virulence factor N1L is a novel promising target for antiviral therapeutic intervention. J Med Chem 53:3899-906
Sidique, Shyama; Shiryaev, Sergey A; Ratnikov, Boris I et al. (2009) Structure-activity relationship and improved hydrolytic stability of pyrazole derivatives that are allosteric inhibitors of West Nile Virus NS2B-NS3 proteinase. Bioorg Med Chem Lett 19:5773-7
Hayashi, Hideki; Cuddy, Michael; Shu, Vincent Chih-Wen et al. (2009) Versatile assays for high throughput screening for activators or inhibitors of intracellular proteases and their cellular regulators. PLoS One 4:e7655