title: Effects of Resistance-Associated NS5A Mutations in Hepatitis C Virus on Viral Production and Susceptibility to Antiviral Reagents.
abstract: Direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have potent anti-HCV effects but may provoke resistance-associated variants (RAVs). In this study, we assessed the characteristics of these RAVs and explored efficacious anti-HCV reagents using recombinant HCV with NS5A from a genotype 1b strain. We replaced the NS5A of JFH1 with that of Con1 (JFH1/5ACon1) and introduced known NS5A inhibitor resistance mutations (L31M, L31V, L31I and Y93H) individually or in combination. Susceptibilities against anti-HCV reagents were also investigated. RAVs with Y93H exhibited high extracellular core antigen levels and infectivity titers. Variants with any single mutation showed mild to moderate resistance against NS5A inhibitors, whereas variants with double mutations at both L31 and Y93 showed severe resistance. The variants with mutations exhibited similar levels of susceptibility to interferon (IFN)-α, IFN-λ1, IFN-λ3 and Ribavirin. Variants with the Y93H mutation were more sensitive to protease inhibitors compared with JFH1/5ACon1. In conclusion, the in vitro analysis indicated that the Y93H mutation enhanced infectious virus production, suggesting advantages in the propagation of RAVs with this mutation. However, these RAVs were susceptible to protease inhibitors. Thus, a therapeutic regimen that includes these reagents is a promising means to eradicate these RAVs.
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.|Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.|Faculty of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Nitta
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.|Department of Liver Disease Control, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Asahina
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Yamada
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Sugiyama
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Masaki
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kato
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Takaji
authors.initials: T
authors.lastname: Wakita
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Kato
mesh_terms: D019943:Amino Acid Substitution; D000998:Antiviral Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D024882:Drug Resistance, Viral / Q000235:genetics*; D016174:Hepacivirus / Q000235:genetics / Q000378:metabolism; D006526:Hepatitis C / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007372:Interferons / Q000494:pharmacology; D020125:Mutation, Missense; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase
chemical_list: D000998:Antiviral Agents; D007372:Interferons; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase