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丙型肝炎病毒(Hepatitis C virus,HCV)是散发性及输血后肝炎的主要病原体,易致慢性肝炎、肝硬变或肝细胞癌。为了研究中国HCV基因组的变异及结构特征,我们从中国丙型肝炎(丙肝,Hepatitis C,HC)患者血浆中提取HCV基因RNA,用随机引物合成HCV cDNA并构建其λgtll cDNA库。对此基因库进行了免疫筛选,并对2个阳性克隆(Q349和Q653)在pUC18质粒中进行了亚克隆。序列分析结果表明:Q349和Q653分别来自HCV基因组核心(C)区(第554～902位)和非结构3(NS3)区(第4175～4827位)。Q349和Q653与HCV原型相应序列在核苷酸和氨基酸水平上的同源性分别为86.8％,80.2％和97.3％,93.1％;与日本HCV相应序列间有更高的同源性,故属于HCVⅡ组。特异性灾验表明,Q349和Q653的编码多肽可与HC人群血清特异反应而不与正常人血清反应,且Q653与中国HC血清反应的阳性率(95.8％)比日本HC血清的阳性率(85.7％)高。表明根据中国HCV基因序列(特别是非结构区序列)设计引物或合成多肽将更适合中国人群HCV感染的检出。
Hepatitis C virus (HCV) is a major pathogen of sporadic and post-transfusion hepatitis and is prone to chronic hepatitis, cirrhosis or hepatocellular carcinoma. In order to study the variation and structural characteristics of HCV genome in China, we extracted HCV RNA from the plasma of patients with hepatitis C (Hepatitis C, HC) and synthesized the cDNA of λgtll with random primers. The gene pool was immunoscreened and 2 positive clones (Q349 and Q653) were subcloned in pUC18 plasmid. The results of sequence analysis showed that Q349 and Q653 were from core region (554-1092) and non-structure 3 (4175-4827) of HCV genome, respectively. The nucleotide and amino acid homologies of Q349 and Q653 to the corresponding HCV prototype sequences were 86.8%, 80.2%, 97.3% and 93.1%, respectively. HCV Ⅱ group. Specific tests showed that the Q349 and Q653-encoding peptides could specifically react with serum of the HC population but not normal human serum, and the positive rate of Q653 and Chinese HC serum (95.8%) was higher than that of Japanese HC serum %)high. It is indicated that the design of primers or synthetic peptides based on the Chinese HCV gene sequences (especially the non-structural sequences) will be more suitable for the detection of HCV infection in Chinese population.