Study On the Variation of E2 of 1b Hepatitis C Virus in the South of Jiangsu Province
Abstract: The aim of this study was to investigate the variation of the second envelope glycoprotein E2 of Hepatitis C Virus strains from the south of Jiangsu province and to learn about the relationship between HCV quasispecies and alanine aminotransferase (ALT). Identification genotypes of sera samples obtained from 166 donors who were HCV positive was carried our by the PCR with type specific primers based on the sequence of 5′non-coding region (5′NCR). Forty-three chronic 1b type hepatitis C patients who had not received any antiviral therapy were categorized into two groups according to the ALT level. HCV quasispecies diversity were determined by RT-PCR single-strand conformational polymorphism analysis of E2/NS1. Ten strains of HCV E2 were sequenced. A phylogenetic tree of HCV E2 sequences was constructed by using CLUSTAL W and PHYLIP. Out of total 166 patients, 102 were HCV RNA positive in which 86 patients had genotype 1b(86/102; 84.3%), 6 patients had genotype 2 (6/102; 5.9%), 5 patients was1b/2 mixed types (5/102; 4.9%) and a genotype could not be determined in 5 patients. Phylogeny confirmed that variation in the HCV E2 region was not random but with several conservative gene sequences and amino acid in fixed sites. The quasispecies bands numbers for 43 strains were significantly different with 2.54±1.05 and 4.48±2.14, respectively. Logistic regression analysis also found the quasispecies diversity was an influencing factor in ALT level. Type 1b was the predominant HCV genotype in this area. Phylogenetic trees of HCV E indicated that HCV strains in south of JIANGSU province was close to the ones from SHANGHAI and JAPAN. Some conservative sites were fixed in HCV E region. Quasispecies diversity was correlated with ALT level.