Dengue virus (DENV) is the most clinically important arbovirus and a Category A bioterrorism agent. As with other positive stranded RNA viruses, DENV rearranges cellular membranes to establish unique cytosolic structures that are the sites of replication complex formation. We found that DENV co-opts cellular fatty acid biosynthesis to establish its sites of replication. The viral NS3 protein binds to fatty acid synthase (FASN), recruits it to sites of viral replication, and stimulates its activity. The NS3 domain required for FASN binding has been defined. Mutation of the FASN interaction domains established that the NS3-FASN interaction is absolutely essential for replication. Importantly, FASN inhibitors block the replication of DENV and other flaviviruses including West Nile virus and yellow fever virus. Additionally the FASN pathway has been implicated in the replication of many other viruses, including HIV, HCV, influenza, and HCMV. This suggests that FASN inhibitors may be a broad spectrum antiviral therapeutic if tolerated. We have identified a FASN inhibitor lead compound, IPI- 9119, that fits this criteria. It inhibits FASN in cell culture and in the liver and lungs of ice. The compound is orally bioavailable and irreversibly inhibits the thioesterase domain of FASN. Toxicity studies in vitro and in mice demonstrate that the inhibitor is well tolerated with minimal toxicity issues. This project is a collaboration between three groups. The Randall lab has characterized the DENV- FASN interaction and has assessed antiviral activity of FASN inhibitors in vitro. The Diamond lab are leaders in flavivirus research and are highly experienced with DENV and West Nile Virus animal models and inhibitor testing. The Infinity group developed the FASN inhibitor class and characterized its efficacy and (lack of) toxicity in vivo. They have expertise in medicinal chemistry, animal toxicity testing, and analysis of IND-enabling studies. We propose to test the efficacy of this compound against DENV and WNV infection in vitro and in mouse models and then build toward an IND filing. We will validate the efficacy of FASN inhibitors against DENV infection in vitro and in vivo. Anti-DENV activity will be characterized in cell culture and mouse models, while mechanisms of resistance are evaluated. Further drug evaluation assessing pharmacokinetics, pharmacodynamics, and various toxicity assays will be performed to advance these compounds toward IND filing. This project will move a likely broad-spectrum antiviral that targets a well-characterized virus-host interaction in dengue virus replication inhibitor into IND filing for clinical trials. Importantly, although the inhibitor targets an important cellular enzyme, it is non-toxic in mice.

Public Health Relevance

Dengue virus (DENV) is the most clinically important arbovirus with 50-100 million infections annually and a Category A bioterrorism agent. We have discovered that DENV interacts with and absolutely required the cellular enzyme fatty acid synthase (FASN) for its replication and have developed a class of inhibitors against FASN that are active in vitro and well tolerated. We propose to characterize the efficacy of these inhibitors against DENV infection in vitro and in animal models and perform further toxicity studies that will move these inhibitors toward IND filing.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21AI102236-01
Application #
8391479
Study Section
Special Emphasis Panel (ZAI1-RRS-M (M2))
Program Officer
Tseng, Christopher K
Project Start
2012-07-01
Project End
2014-06-30
Budget Start
2012-07-01
Budget End
2013-06-30
Support Year
1
Fiscal Year
2012
Total Cost
$223,414
Indirect Cost
$50,399
Name
University of Chicago
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637
Chukkapalli, Vineela; Randall, Glenn (2014) Hepatitis C virus replication compartment formation: mechanism and drug target. Gastroenterology 146:1164-7
Schoggins, John W; Randall, Glenn (2013) Lipids in innate antiviral defense. Cell Host Microbe 14:379-85