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/NS3-1 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 > 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.


CONCLUSIONS
The primary structure of the HCV NS3 region is highly variable. Thus, sequence variability has a profound effect on the antigenic properties of the NS3 regions, and the antigenic differences should be taken into account for the development of more effective diagnostic tests.
Qiao
Weizhen
W
Department of Central Laboratory, Affiliated Wuxi People's Hospital, Nanjing Medical University, Wuxi, PR China.
Xie
Ping
P
Cai
Bing
B
Li
Lingling
L
D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D014644:Genetic Variation; D005838:Genotype; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D006526:Hepatitis C / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D012698:Serologic Tests; D012703:Serotyping; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000956:Antigens, Viral; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases