title: Variations of hepatitis C virus NS5B sequence (nucleotides 8261-8566) do not correlate with response to interferon-alpha therapy.
abstract: Hepatitis C virus (HCV) is an RNA virus with the NS5B gene encoding an RNA-dependent RNA polymerase. Interferon-alpha (IFN-alpha) is effective against HCV and its effect is believed to be related to its antiviral activity. To determine whether sequence variations of the HCV NS5B region correlate with response to IFN therapy, pretreatment serum samples from 40 patients with chronic HCV infection who were subsequently treated with IFN (> or = 3 MU thrice weekly for 24 weeks) and had well-characterized biochemical responses were studied. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to generate an approximately 365-bp fragment from which nucleotide sequence and genotypes were determined. By comparing the nucleotide sequences and the encoded amino acid sequences of samples from each group, no response group-specific nucleotide or encoded amino acid substitution was identified. Most of the substitutions identified were synonymous (usually by changes at the third position of the codon). These data suggest that these substitutions were selective rather than spontaneous events. Of the few non-synonymous substitutions identified, none was correlated with subsequent response to IFN, either within or across genotypes.
authors.affiliation: Department of Medicine, University of Florida, Gainesville 32610, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Nelson
authors.forename: A H
authors.initials: AH
authors.lastname: Gray
authors.forename: J A
authors.initials: JA
authors.lastname: Kolberg
authors.forename: J
authors.initials: J
authors.lastname: Joh
authors.forename: M S
authors.initials: MS
authors.lastname: Urdea
authors.forename: M
authors.initials: M
authors.lastname: Mizokami
authors.forename: G L
authors.initials: GL
authors.lastname: Davis
authors.forename: J Y
authors.initials: JY
authors.lastname: Lau
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000627:therapeutic use*; D001483:Base Sequence; D005260:Female; D014644:Genetic Variation; D016174:Hepacivirus / Q000737:chemistry* / Q000235:genetics*; D006526:Hepatitis C / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D012324:RNA-Dependent RNA Polymerase