title: Sequencing of E2 and NS5A regions of HCV genotype 3a in Brazilian patients with chronic hepatitis.
abstract: Hepatitis C virus (HCV) is a major cause of liver disease throughout the world. The NS5A and E2 proteins of HCV genotype 1 were reported to inhibit the double-stranded (ds) RNA-dependent protein kinase (PKR), which is involved in the cellular antiviral response induced by interferon (IFN). The response to IFN therapy is quite different between genotypes, with response rates among patients infected with types 2 and 3 that are two-three-fold higher than in patients infected with type 1. Interestingly, a significant percentage of HCV genotype 3-infected patients do not respond to treatment at all. The aim of this paper was to analyse the sequences of fragments of the E2 and NS5A regions from 33 outpatients infected with genotype 3a, including patients that have responded (SVR) or not responded (NR) to treatment. HCV RNA was extracted and amplified with specific primers for the NS5A and E2 regions and the PCR products were then sequenced. The sequences obtained covered amino acids (aa) 636-708 in E2 and in NS5A [including the IFN sensitivity determining region (ISDR), PKR-binding domain and extended V3 region)]. In the E2 and NS5A regions, we did observe aa changes among patients, but these changes were not statistically significant between the SVR and NR groups. In conclusion, our results suggest that the ISDR domain is not predictive of treatment success in patients infected with HCV genotype 3a.
authors.affiliation: Departamento de Gastroenterologia, Laboratório de Gastroenterologia e Hepatologia Tropical, Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brasil. femalta@yahoo.com
authors.forename: Fernanda de Mello
authors.initials: Fde M
authors.lastname: Malta
authors.forename: José Eymard Moraes de
authors.initials: JE
authors.lastname: Medeiros-Filho
authors.forename: Raymundo Soares de
authors.initials: RS
authors.lastname: Azevedo
authors.forename: Luzia
authors.initials: L
authors.lastname: Gonçalves
authors.forename: Luiz Caetano da
authors.initials: LC
authors.lastname: Silva
authors.forename: Flair José
authors.initials: FJ
authors.lastname: Carrilho
authors.forename: João Renato Rebello
authors.initials: JR
authors.lastname: Pinho
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000627:therapeutic use; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics*; D012254:Ribavirin / Q000627:therapeutic use; D014759:Viral Envelope Proteins / Q000235:genetics*; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D012367:RNA, Viral; D012254:Ribavirin; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins; C091015:glycoprotein E2, Hepatitis C virus; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase