title: Discovery of a novel compound with anti-venezuelan equine encephalitis virus activity that targets the nonstructural protein 2.
abstract: Alphaviruses present serious health threats as emerging and re-emerging viruses. Venezuelan equine encephalitis virus (VEEV), a New World alphavirus, can cause encephalitis in humans and horses, but there are no therapeutics for treatment. To date, compounds reported as anti-VEEV or anti-alphavirus inhibitors have shown moderate activity. To discover new classes of anti-VEEV inhibitors with novel viral targets, we used a high-throughput screen based on the measurement of cell protection from live VEEV TC-83-induced cytopathic effect to screen a 340,000 compound library. Of those, we identified five novel anti-VEEV compounds and chose a quinazolinone compound, CID15997213 (IC50 = 0.84 µM), for further characterization. The antiviral effect of CID15997213 was alphavirus-specific, inhibiting VEEV and Western equine encephalitis virus, but not Eastern equine encephalitis virus. In vitro assays confirmed inhibition of viral RNA, protein, and progeny synthesis. No antiviral activity was detected against a select group of RNA viruses. We found mutations conferring the resistance to the compound in the N-terminal domain of nsP2 and confirmed the target residues using a reverse genetic approach. Time of addition studies showed that the compound inhibits the middle stage of replication when viral genome replication is most active. In mice, the compound showed complete protection from lethal VEEV disease at 50 mg/kg/day. Collectively, these results reveal a potent anti-VEEV compound that uniquely targets the viral nsP2 N-terminal domain. While the function of nsP2 has yet to be characterized, our studies suggest that the protein might play a critical role in viral replication, and further, may represent an innovative opportunity to develop therapeutic interventions for alphavirus infection.
authors: Departments of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America; Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America.
authors: Dong-Hoon
authors: DH
authors: Chung
authors: Departments of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America; Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America; Department of Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, United States of America.
authors: Colleen B
authors: CB
authors: Jonsson
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: Nichole A
authors: NA
authors: Tower
authors: Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America.
authors: Yong-Kyu
authors: YK
authors: Chu
authors: Departments of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America; Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America.
authors: Ergin
authors: E
authors: Sahin
authors: University of Kansas Specialized Chemistry Center, Lawrence, Kansas, United States of America.
authors: Jennifer E
authors: JE
authors: Golden
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: James W
authors: JW
authors: Noah
authors: University of Kansas Specialized Chemistry Center, Lawrence, Kansas, United States of America.
authors: Chad E
authors: CE
authors: Schroeder
authors: Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America.
authors: Julie B
authors: JB
authors: Sotsky
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: Melinda I
authors: MI
authors: Sosa
authors: Center for Predictive Medicine for Biodefense and Emerging Infectious Diseases, University of Louisville, Louisville, Kentucky, United States of America.
authors: Daniel E
authors: DE
authors: Cramer
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: Sara N
authors: SN
authors: McKellip
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: Lynn
authors: L
authors: Rasmussen
authors: Drug Discovery Department, Southern Research Institute, Birmingham, Alabama, United States of America.
authors: E Lucile
authors: EL
authors: White
authors: The United States Army Medical Research Institute for Infectious Diseases, Ft. Detrick, Maryland, United States of America.
authors: Connie S
authors: CS
authors: Schmaljohn
authors: Institute for Antiviral Research, Utah State University, Logan, Utah, United States of America.
authors: Justin G
authors: JG
authors: Julander
authors: The United States Army Medical Research Institute for Infectious Diseases, Ft. Detrick, Maryland, United States of America.
authors: Jeffrey M
authors: JM
authors: Smith
authors: Boston University, Boston, Massachusetts, United States of America.
authors: Claire Marie
authors: CM
authors: Filone
authors: Boston University, Boston, Massachusetts, United States of America.
authors: John H
authors: JH
authors: Connor
authors: Texas Biomedical Research Institute, San Antonio, Texas, United States of America.
authors: Yasuteru
authors: Y
authors: Sakurai
authors: Texas Biomedical Research Institute, San Antonio, Texas, United States of America.
authors: Robert A
authors: RA
authors: Davey
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004195:Disease Models, Animal; D024882:Drug Resistance, Viral / Q000235:genetics; D004666:Encephalitis Virus, Venezuelan Equine / Q000187:drug effects* / Q000235:genetics; D004685:Encephalomyelitis, Venezuelan Equine / Q000188:drug therapy* / Q000821:virology; D057166:High-Throughput Screening Assays; D051379:Mice; D008809:Mice, Inbred C3H; D052999:Quinazolinones / Q000494:pharmacology*; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014709:Vero Cells; D010948:Viral Plaque Assay; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; C000600611:CID15997213; D052999:Quinazolinones