The significant burden that results from dengue virus infection combined with the absence of effective vaccines or drugs makes the development of novel therapeutics a high priority. The process of viral entry is an attractive target for anti-dengue virus inhibitor development because interventions at this point of the viral life cycle can be used both to prevent and to treat infection; moreover, entry inhibitors would complement efforts directed towards development of more traditional viral protease and polymerase inhibitors. Currently, our understanding of the mechanisms of viral entry is insufficient to support rational design of viral entry inhibitors, and high-throughput assays that report on the fusogenic activity of the dengue virus envelope protein, which mediates viral entry, are sorely needed. The goal of this proposal is to develop and validate such assays for submission to the MLPCN. These assays should enable the discovery of inhibitors that block DENV entry at precise points along the pathway between pre- and postfusion conformations of the dengue virus envelope protein, which will provide much-needed tools for characterization of entry intermediates by structural and biochemical methods. This, in turn, will fuel efforts to develop dengue virus entry inhibitors by providing lead structures for optimization as well as by providing valuable mechanistic information to drive rational design efforts.
In Aim 1, we propose to use develop a high-throughput fluorescence polarization assay to identify ligands of the dengue virus envelope protein that inhibit dengue virus infection.
In Aim 2, we propose to develop a secondary assay that will be used to determine if primary screening hits inhibit dengue virus infection by blocking the fusion step of the entry process. Last, in Aim 3, we propose to validate our assay pipeline by screening a diverse 10,000- member compound library. We will use assays developed in Aims 1 and 2 as well as other assays previously developed in our laboratory to characterize the mechanisms of action of compounds with activity against dengue virus. The goal of this research is to validate assay methodology for eventual application in a high-throughput screening campaign against the MLPCN compound collection. A subsequent effort will focus on using these compounds as starting points for a medicinal chemistry campaign to develop optimized compounds that can be evaluated in preclinical and ultimately clinical DENV models and that can be used as mechanistic probes of dengue virus entry.

Public Health Relevance

Dengue virus is the most widespread mosquito-borne virus in the world today and the cause of significant human disease;however, there currently are no vaccines or specific antiviral therapies to prevent or to treat dengue virus infection. The proposed experiments will develop assays to identify small molecules that inhibit dengue virus by preventing the entry of dengue virus into a host cell.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
High Priority, Short Term Project Award (R56)
Project #
1R56AI095499-01
Application #
8337072
Study Section
Drug Discovery and Mechanisms of Antimicrobial Resistance Study Section (DDR)
Program Officer
Cassetti, Cristina
Project Start
2011-09-30
Project End
2013-11-19
Budget Start
2011-09-30
Budget End
2013-11-19
Support Year
1
Fiscal Year
2011
Total Cost
$392,495
Indirect Cost
Name
Harvard University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
Lian, Wenlong; Jang, Jaebong; Potisopon, Supanee et al. (2018) Discovery of Immunologically Inspired Small Molecules That Target the Viral Envelope Protein. ACS Infect Dis 4:1395-1406
de Wispelaere, Melissanne; Lian, Wenlong; Potisopon, Supanee et al. (2018) Inhibition of Flaviviruses by Targeting a Conserved Pocket on the Viral Envelope Protein. Cell Chem Biol 25:1006-1016.e8
Clark, Margaret J; Miduturu, Chandra; Schmidt, Aaron G et al. (2016) GNF-2 Inhibits Dengue Virus by Targeting Abl Kinases and the Viral E Protein. Cell Chem Biol 23:443-52
de Wispelaere, Melissanne; Yang, Priscilla L (2012) Mutagenesis of the DI/DIII linker in dengue virus envelope protein impairs viral particle assembly. J Virol 86:7072-83