title: Rapid emergence of telaprevir resistant hepatitis C virus strain from wildtype clone in vivo.
abstract: Telaprevir is a potent inhibitor of hepatitis C virus (HCV) NS3-4A protease. However, the emergence of drug-resistant strains during therapy is a serious problem, and the susceptibility of resistant strains to interferon (IFN), as well as the details of the emergence of mutant strains in vivo, is not known. We previously established an infectious model of HCV using human hepatocyte chimeric mice. Using this system we investigated the biological properties and mode of emergence of mutants by ultra-deep sequencing technology. Chimeric mice were injected with serum samples obtained from a patient who had developed viral breakthrough during telaprevir monotherapy with strong selection for resistance mutations (A156F [92.6%]). Mice infected with the resistant strain (A156F [99.9%]) developed only low-level viremia and the virus was successfully eliminated with interferon therapy. As observed in patients, telaprevir monotherapy in viremic mice resulted in breakthrough, with selection for mutations that confer resistance to telaprevir (e.g., a high frequency of V36A [52.2%]). Mice were injected intrahepatically with HCV genotype 1b clone KT-9 with or without an introduced resistance mutation, A156S, in the NS3 region, and treated with telaprevir. Mice infected with the A156S strain developed lower-level viremia compared to the wildtype strain but showed strong resistance to telaprevir treatment. Although mice injected with wildtype HCV showed a rapid decline in viremia at the beginning of therapy, a high frequency (11%) of telaprevir-resistant NS3 V36A variants emerged 2 weeks after the start of treatment.
  
  
  CONCLUSIONS
  Using deep sequencing technology and a genetically engineered HCV infection system, we showed that the rapid emergence of telaprevir-resistant HCV was induced by mutation from the wildtype strain of HCV in vivo.
authors.affiliation: Department of Medicine and Molecular Science, Division of Frontier Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hiraga
authors.forename: Michio
authors.initials: M
authors.lastname: Imamura
authors.forename: Hiromi
authors.initials: H
authors.lastname: Abe
authors.forename: C Nelson
authors.initials: CN
authors.lastname: Hayes
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kono
authors.forename: Mayu
authors.initials: M
authors.lastname: Onishi
authors.forename: Masataka
authors.initials: M
authors.lastname: Tsuge
authors.forename: Shoichi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ochi
authors.forename: Eiji
authors.initials: E
authors.lastname: Iwao
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kamiya
authors.forename: Ichimaro
authors.initials: I
authors.lastname: Yamada
authors.forename: Chise
authors.initials: C
authors.lastname: Tateno
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Yoshizato
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Matsui
authors.forename: Akinori
authors.initials: A
authors.lastname: Kanai
authors.forename: Toshiya
authors.initials: T
authors.lastname: Inaba
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D046528:Chimerism; D024882:Drug Resistance, Viral; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D008875:Middle Aged; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000998:Antiviral Agents; D009842:Oligopeptides; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C486464:telaprevir