TY - JOUR
T1 - Efficient hepatitis C virus genotype 1b Core-NS5A recombinants permit efficacy testing of protease and NS5A inhibitors
AU - Van Pham, Long
AU - Ramirez, Santseharay
AU - Carlsen, Thomas H R
AU - Li, Yi-Ping
AU - Gottwein, Judith M
AU - Bukh, Jens
N1 - Copyright © 2017 American Society for Microbiology.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Hepatitis C virus (HCV) strains belong to seven genotypes with numerous subtypes, responding differently to antiviral therapies. Genotype 1, and primarily subtype 1b, is the most prevalent worldwide. The development of recombinant HCV infectious cell-culture systems for different variants, permitted by the high replication capacity of strain JFH1 (genotype 2a), has advanced efficacy and resistance testing of antivirals. However, efficient infectious JFH1-based cell cultures of subtype 1b are limited and comprise only the 5' UTR-NS2, NS4A, and NS5A regions. Importantly, it has not been possible to develop efficient 1b infectious systems expressing the NS3/NS4A protease, an important target of direct-acting antivirals. We developed efficient infectious JFH1-based cultures with genotype 1b Core-NS5A sequences of strains DH1, Con1, and J4, by using previously identified HCV cell-culture adaptive substitutions A1226G, R1496L, and Q1773H. These viruses spread efficiently in Huh7.5 cells by acquiring additional adaptive substitutions, and final recombinants yielded peak supernatant infectivity titers of 4-5 log10 focus-forming-units/ml. We subsequently succeeded in adapting a JFH1-based 5' UTR-NS5A DH1 recombinant to efficient growth in cell culture. We evaluated efficacy of clinically relevant NS3/4A protease- and NS5A-inhibitors against the novel genotype 1b viruses, as well as against previously developed 1a viruses. The inhibitors were efficient against all tested genotype 1 viruses, with NS5A inhibitors showing half-maximal effective concentrations several orders of magnitude lower than NS3/4A protease inhibitors. In summary, the developed HCV genotype 1b culture systems represent valuable tools for assessing the efficacy of various classes of antivirals, and for other virological studies requiring genotype 1b infectious viruses.
AB - Hepatitis C virus (HCV) strains belong to seven genotypes with numerous subtypes, responding differently to antiviral therapies. Genotype 1, and primarily subtype 1b, is the most prevalent worldwide. The development of recombinant HCV infectious cell-culture systems for different variants, permitted by the high replication capacity of strain JFH1 (genotype 2a), has advanced efficacy and resistance testing of antivirals. However, efficient infectious JFH1-based cell cultures of subtype 1b are limited and comprise only the 5' UTR-NS2, NS4A, and NS5A regions. Importantly, it has not been possible to develop efficient 1b infectious systems expressing the NS3/NS4A protease, an important target of direct-acting antivirals. We developed efficient infectious JFH1-based cultures with genotype 1b Core-NS5A sequences of strains DH1, Con1, and J4, by using previously identified HCV cell-culture adaptive substitutions A1226G, R1496L, and Q1773H. These viruses spread efficiently in Huh7.5 cells by acquiring additional adaptive substitutions, and final recombinants yielded peak supernatant infectivity titers of 4-5 log10 focus-forming-units/ml. We subsequently succeeded in adapting a JFH1-based 5' UTR-NS5A DH1 recombinant to efficient growth in cell culture. We evaluated efficacy of clinically relevant NS3/4A protease- and NS5A-inhibitors against the novel genotype 1b viruses, as well as against previously developed 1a viruses. The inhibitors were efficient against all tested genotype 1 viruses, with NS5A inhibitors showing half-maximal effective concentrations several orders of magnitude lower than NS3/4A protease inhibitors. In summary, the developed HCV genotype 1b culture systems represent valuable tools for assessing the efficacy of various classes of antivirals, and for other virological studies requiring genotype 1b infectious viruses.
KW - Journal Article
U2 - 10.1128/AAC.00037-17
DO - 10.1128/AAC.00037-17
M3 - Journal article
C2 - 28348150
SN - 0066-4804
VL - 61
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
IS - 6
ER -