Lassa and Ebola virus inhibitors identified using minigenome and recombinant virus reporter systems

Antiviral Res. 2016 Dec:136:9-18. doi: 10.1016/j.antiviral.2016.10.007. Epub 2016 Oct 19.

Abstract

Lassa virus (LASV) and Ebola virus (EBOV) infections are important global health issues resulting in significant morbidity and mortality. While several promising drug and vaccine trials for EBOV are ongoing, options for LASV infection are currently limited to ribavirin treatment. A major factor impeding the development of antiviral compounds to treat these infections is the need to manipulate the virus under BSL-4 containment, limiting research to a few institutes worldwide. Here we describe the development of a novel LASV minigenome assay based on the ambisense LASV S segment genome, with authentic terminal untranslated regions flanking a ZsGreen (ZsG) fluorescent reporter protein and a Gaussia princeps luciferase (gLuc) reporter gene. This assay, along with a similar previously established EBOV minigenome, was optimized for high-throughput screening (HTS) of potential antiviral compounds under BSL-2 containment. In addition, we rescued a recombinant LASV expressing ZsG, which, in conjunction with a recombinant EBOV reporter virus, was used to confirm any potential antiviral hits in vitro. Combining an initial screen to identify potential antiviral compounds at BSL-2 containment before progressing to HTS with infectious virus will reduce the amount of expensive and technically challenging BSL-4 containment research. Using these assays, we identified 6-azauridine as having anti-LASV activity, and demonstrated its anti-EBOV activity in human cells. We further identified 2'-deoxy-2'-fluorocytidine as having potent anti-LASV activity, with an EC50 value 10 times lower than that of ribavirin.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology*
  • Azauridine / pharmacology
  • Deoxycytidine / analogs & derivatives
  • Deoxycytidine / pharmacology
  • Drug Discovery / methods
  • Ebolavirus / drug effects*
  • Ebolavirus / genetics*
  • Genes, Reporter
  • Genome, Viral
  • Green Fluorescent Proteins / genetics
  • Hemorrhagic Fever, Ebola
  • High-Throughput Screening Assays / methods
  • Humans
  • Lassa Fever
  • Lassa virus / drug effects*
  • Lassa virus / genetics*
  • Luciferases / genetics

Substances

  • Antiviral Agents
  • Deoxycytidine
  • Green Fluorescent Proteins
  • Azauridine
  • Luciferases
  • 2'-fluoro-2'-deoxycytidine