Sequencing of E2 and NS5A regions of HCV genotype 3a in Brazilian patients with chronic hepatitis

Fernanda de Mello Malta, José Eymard Moraes de Medeiros-Filho, Raymundo Soares de Azevedo, Luzia Gonçalves, Luiz Caetano da Silva, Flair José Carrilho, João Renato Rebello Pinho
2010 Memórias do Instituto Oswaldo Cruz  
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.
more » ... gly, 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. Key words: E2 protein -hepatitis C virus -interferon sensitivity determining region -NS5A protein -PKR-eIF2a phosphorylation homology domain Financial support: FAPESP (00/11457-1), Alves de Queiroz Family Fund for Research
doi:10.1590/s0074-02762010000100014 pmid:20209336 fatcat:lfqb47yrz5fvpdhovmbnn62p3a