Luciferase Assay: The Huh-7 cells transfected with HCV replicons system were seeded into 96-well plates (8,000 cells in 125 μL/well) respectively; each test compound was diluted to desired concentration using 5-fold serial dilutions protocol, 10 doses in duplicate, and added to wells with POD™ 810 Plate Assembler. The plates were incubated in a CO2 incubator for 72 hours; after that, 40 μL of Luciferase assay substrate (Promega Bright-Glo) was added to each well, and detected by a chemiluminescence detection system (Topcount Microplate Scintillation and Luminescence Counter) 5 minutes later; the EC50 (half-maximal effective concentration, concentration for 50% of maximal effect) values of test compounds were analyzed by GraphPad Prism software, respectively. In this paper, experiments were repeated twice and set the holes without compounds as negative control.
Luciferase Assay: The Huh-7 cells transfected with HCV replicons system were seeded into 96-well plates (8,000 cells in 125 μL/well) respectively; each test compound was diluted to desired concentration using 5-fold serial dilutions protocol, 10 doses in duplicate, and added to wells with POD™ 810 Plate Assembler. The plates were incubated in a CO2 incubator for 72 hours; after that, 40 μL of Luciferase assay substrate (Promega Bright-Glo) was added to each well, and detected by a chemiluminescence detection system (Topcount Microplate Scintillation and Luminescence Counter) 5 minutes later; the EC50 (half-maximal effective concentration, concentration for 50% of maximal effect) values of test compounds were analyzed by GraphPad Prism software, respectively. In this paper, experiments were repeated twice and set the holes without compounds as negative control.
Transient Replicon Assay: In a transient set-up, a Huh-7 lunet hepatoma cell line was transiently transfected with an autonomously replicating RNA encoding a bi-cistronic expression construct. This construct comprises a firefly luciferase reporter gene preceding the NS3-NS5B subgenomic region of HCV (genotype 1a H77 or 1b Con1). Translation of the HCV subgenomic region is mediated by an internal ribosome entry site of encephalomyocarditis virus. The construct is furthermore flanked by 5' and 3' untranslated regions of HCV (genotype 1a H77 or 1b Con 1, respectively), which allow for replication of the RNA. In addition to the wild-type constructs, site-directed mutations were introduced into the transient HCV genotype 1b replicon in the gene encoding for the non-structural protein 5A (NS5A). More precisely, amino acid residues 28, 30, 31 and 93 in NS5A were independently altered. Cells were plated in 384 well plates in the presence of test and control compounds, which were added in various concentrations. Following an incubation of two days, replication of the HCV subgenomic replicon RNA was measured by assaying luciferase activity (using standard luciferase assay substrates and reagents and a Perkin Elmer ViewLux™ ultraHTS microplate imager). HCV subgenomic replicon containing cells in the control cultures have high luciferase expression in the absence of any inhibitor. The inhibitory activity of the compound was monitored, enabling a dose-response curve for each test compound.
Transient Replicon Assay: In a transient set-up, a Huh-7 lunet hepatoma cell line was transiently transfected with an autonomously replicating RNA encoding a bi-cistronic expression construct. This construct comprises a firefly luciferase reporter gene preceding the NS3-NS5B subgenomic region of HCV (genotype 1a H77 or 1b Con1). Translation of the HCV subgenomic region is mediated by an internal ribosome entry site of encephalomyocarditis virus. The construct is furthermore flanked by 5' and 3' untranslated regions of HCV (genotype 1a H77 or 1b Con 1, respectively), which allow for replication of the RNA. In addition to the wild-type constructs, site-directed mutations were introduced into the transient HCV genotype 1b replicon in the gene encoding for the non-structural protein 5A (NS5A). More precisely, amino acid residues 28, 30, 31 and 93 in NS5A were independently altered. Cells were plated in 384 well plates in the presence of test and control compounds, which were added in various concentrations. Following an incubation of two days, replication of the HCV subgenomic replicon RNA was measured by assaying luciferase activity (using standard luciferase assay substrates and reagents and a Perkin Elmer ViewLux™ ultraHTS microplate imager). HCV subgenomic replicon containing cells in the control cultures have high luciferase expression in the absence of any inhibitor. The inhibitory activity of the compound was monitored, enabling a dose-response curve for each test compound.
Transient Replicon Assay: In a transient set-up, a Huh-7 lunet hepatoma cell line was transiently transfected with an autonomously replicating RNA encoding a bi-cistronic expression construct. This construct comprises a firefly luciferase reporter gene preceding the NS3-NS5B subgenomic region of HCV (genotype 1a H77 or 1b Con1). Translation of the HCV subgenomic region is mediated by an internal ribosome entry site of encephalomyocarditis virus. The construct is furthermore flanked by 5' and 3' untranslated regions of HCV (genotype 1a H77 or 1b Con 1, respectively), which allow for replication of the RNA. In addition to the wild-type constructs, site-directed mutations were introduced into the transient HCV genotype 1b replicon in the gene encoding for the non-structural protein 5A (NS5A). More precisely, amino acid residues 28, 30, 31 and 93 in NS5A were independently altered. Cells were plated in 384 well plates in the presence of test and control compounds, which were added in various concentrations. Following an incubation of two days, replication of the HCV subgenomic replicon RNA was measured by assaying luciferase activity (using standard luciferase assay substrates and reagents and a Perkin Elmer ViewLux™ ultraHTS microplate imager). HCV subgenomic replicon containing cells in the control cultures have high luciferase expression in the absence of any inhibitor. The inhibitory activity of the compound was monitored, enabling a dose-response curve for each test compound.