Antigenic Heterogeneity of the NS3 Proteins in Hepatitis C Virus Genotypes 1 and 6

Objective: To investigate the effect of sequence variability between different genotypes of hepatitis C virus (HCV) on the antigenic properties of the NS3 proteins, and to evaluate the significance of the proteins in the serological diagnosis. Methods: The recombinant expression plasmids of pET/NS31 and pET/NS3-6 were constructed with the NS3 region fragments from HCV genotypes 1 and 6, respectively. The antigenic reactivity of the recombinant NS3 proteins was determined. The NS3 nucleotide sequences were aligned with 6 HCV full-length strains representing different genotypes. Results: The two recombinant NS3 proteins were generated and enzyme immunoassay tests were developed. The positive rates of anti-NS3 were 61.2 and 58.8% by using the NS3 antigens from HCV genotypes 1 and 6, respectively. This difference had no statistical significance (p 1 0.05). However, it was interesting that 16 samples gave a discordant result for different genotype NS3 antigens. The two partial NS3 sequences shared approximately 63.9–79.9% identity with the different genotype strains. Conclusion: The primary structure of the HCV NS3 region is highly variable. Thus, sequence Received: August 17, 2009 Accepted after revision: May 24, 2010 Published online: September 10, 2010 Weizhen Qiao Department of Central Laboratory, Affiliated Wuxi People’s Hospital Nanjing Medical University, No. 299 Qingyang Road Wuxi 214023 (PR China) Tel. +86 510 8535 0355, Fax +86 510 8535 0555, E-Mail yun8220 @ sina.com © 2010 S. Karger AG, Basel 0300–5526/11/0542–0053$38.00/0 Accessible online at: www.karger.com/int D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /1 9/ 20 17 1 0: 10 :4 9 A M