title: Development of a novel dicistronic reporter-selectable hepatitis C virus replicon suitable for high-throughput inhibitor screening.
abstract: Hepatitis C virus (HCV) research and drug discovery have been facilitated by the introduction of cell lines with self-replicating subgenomic HCV replicons. Early attempts to carry out robust, high-throughput screens (HTS) using HCV replicons have met with limited success. Specifically, selectable replicons have required laborious reverse transcription-PCR quantitation, and reporter replicons have generated low signal-to-noise ratios. In this study, we constructed a dicistronic single reporter (DSR)-selectable HCV replicon that contained a humanized Renilla luciferase (hRLuc) gene separated from the selectable Neo(r) marker by a short peptide cleavage site. The mutations E1202G, T1280I, and S2197P were introduced to enhance replicative capability. A dicistronic dual-reporter HCV replicon cell line (DDR) was subsequently created by transfection of Huh-7 cells with the DSR replicon to monitor antiviral activity and by the introduction of the firefly luciferase (FLuc) reporter gene into the host cell genome to monitor cytotoxicity. The DDR cell line demonstrated low signal variation within the HTS format, with a calculated Z' value of 0.8. A pilot HTS consisting of 20 96-well plates with a single concentration (10 microM) of 1,760 different compounds was executed. Hits were defined as compounds that reduced hRLuc and FLuc signals > or =50 and < or =40%, respectively, relative to those in a compound-free control. Good reproducibility was demonstrated, with a calculated confirmation rate of >75%. The development of a robust, high-throughput HCV replicon assay where the effects of inhibitors can be monitored for antiviral activity and cytotoxicity should greatly facilitate HCV drug discovery.
authors.affiliation: Pfizer Global Research and Development, 10777 Science Center Drive, San Diego, CA 92121, USA.
authors.forename: Weidong
authors.initials: W
authors.lastname: Hao
authors.forename: Koleen J
authors.initials: KJ
authors.lastname: Herlihy
authors.forename: Noelle Jie
authors.initials: NJ
authors.lastname: Zhang
authors.forename: Shella A
authors.initials: SA
authors.lastname: Fuhrman
authors.forename: Chau
authors.initials: C
authors.lastname: Doan
authors.forename: Amy K
authors.initials: AK
authors.lastname: Patick
authors.forename: Rohit
authors.initials: R
authors.lastname: Duggal
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D004004:Dichlororibofuranosylbenzimidazole / Q000737:chemistry / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical / Q000379:methods; D024882:Drug Resistance, Viral / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics*; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008156:Luciferases / Q000235:genetics; D012093:Replicon / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017361:Viral Nonstructural Proteins / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics
chemical_list: D000998:Antiviral Agents; D017361:Viral Nonstructural Proteins; D004004:Dichlororibofuranosylbenzimidazole; D008156:Luciferases