丙型肝炎病毒不同基因型NS3蛋白的抗原异质性分析

目的探讨不同基因型丙型肝炎病毒(HCV)NS3蛋白的抗原特性及其用于抗-HCV检测的意义。方法分别构建和表达含有HCV1型和6型NS3基因片段的重组质粒和重组蛋白，以EIJSA法和Western blot分析不同基因型重组蛋白与已知抗-HCV阳性血清的抗原反应性。结果HCV1型和6型NS3重组蛋白氨基酸序列的同源性为83．2％；85份抗-HCV阳性血清以此不同基因型HCV NS3单片段抗原检测，阳性检出率分别为61．2％(1型)和58．8％(6型)，其中有7份标本以NS3-1型抗原检测阴性，但可被NS3-6型抗原检出，反之，有9份血清以NS3-6型重组蛋白检测为阴性，而NS3．1型检测阳性；54份大学生体检血清和39份阴性质控血清以此两种抗原检测均为阴性。结论HCV1型和6型NS3重组蛋白存在抗原异质性，在发展HCV抗体检测试剂时需考虑加入不同基因型的NS3抗原。

Antigenic heterogeneity of the hepatitis C virus NS3 proteins derived from different genotypes

Objective To characterize the antigenicity of the hepatitis C virus (HCV) NS3 recombinant proteins derived from different genotypes and to identify the significance of the proteins used for anti-HCV detection. Methods The recombinant plasmids of pET-NS3-1 and pET-NS3-6 were constructed with pET-28a-c vector and PCR products of HCV NS3 regions derived from HCV genotype 1 and 6 respectively. The antigenic heterogeneity of the HCV NS3 proteins was determined by ELISA and Western blot with the known anti-HCV-positive serum samples. Results The homology of the amino acid sequences of the HCV NS3 recombinant proteins was 83.2% between HCV genotype 1 and 6. The positive rates of anti-NS3 were 61.2% by using the NS3 antigen from HCV genotype 1 and 58.8% by using the antigen from genotype 6, respectively, among 85 known anti-HCV-positive specimens. However, 7 specimens detected with the antigen from genotype 1 were negative but positive when detected with the antigen from genotype 6. On the contrary, 9 specimens were negative with the HCV NS3 antigen from genotype 6 but were positive with the antigen from genotype 1. Fifty-four serum samples collected from normal undergraduates and 39 specimens from an anti-HCV-negative panel were both negative detected by both the NS3 antigens. Conclusion Antigenic heterogeneity of HCV NS3 proteins exists between HCV genotype 1 and 6 and has a profound effect on the anti-HCV detection. This observation should be taken into consideration in the further development of diagnostic assays for the detection of anti-HCV activity.