庚型肝炎病毒E区部分基因克隆及序列分析

Cloning and sequential analyse of partial genuine In E region of hepatitis G virus/GB virus-C

目的 建立适合我国国情的ＨＧＶ诊断方法及进一步研制预防ＨＧ的疫苗。方法 通过逆转录－套式－聚合酶链反应，从 １例输血后丙肝患者血清中扩增出 ７６８ ｂｐ的庚型肝炎病毒ｃＤＮＡ序列，反应产物克隆进 Ｍ１３ｍｐ１８噬菌体，阳性克隆抽提单链以双脱氧终止法双向测定其序列。结果 所分离的 ＨＧＶ Ｅ区 ７６８ ｂｐ的核苷酸与国内外已发表的 ４株ＨＧＶ序列比较，同源性分别为：Ｕ４４４０２ ８１．５％，Ｕ４５９６６ ８２．８％，Ｕ３６３８０ ８４．５％，Ｕ７５３５６ ９５．８％；根据所测得的 ｃＤＮＡ序列推导出其编码的氨基酸序列，在氨基酸水平上较４株ＨＧＶ序列同源性分别为：Ｕ４４４０２ ８７．７％，Ｕ４５９６６ ９１．５％，Ｕ３６３８０ ９４．１％，Ｕ７５３５６ ９５．８％。结论 证实国内存在丙型肝炎与庚型肝炎病毒合并感染；此序列与中国株 ＨＧＶ同源性较高，与美国株ＨＧＶ及西非株（ＧＢＶ－Ｃ）同源性相对较低；推导出的氨基酸水平的同源性高于核苷酸水平．ＨＧＶ Ｅ区较非结构区 ＮＳ３、ＮＳ５及 ５’非编码区（５’ＵＴＲ）的变异为大．

Objective To make the diagnostic methods of HGV adapt to China and to study the vaccine for prevent-ing HG further. Methods The reverse transcription-nested-polymerase chain reaction (RT-nested-PCR) was used to detect the serum of a patient with post-transfusion of hepatitis C. The PCR product, 768 bp in length,was cloned into M13mp18 vectors,and the insert was sequenced from both directions using the Sanger's method after screening. Results The extracted single-strand and purificated partial HGV envelope region genome was compared with 4 isolates from na-tive and foreign countries. The nucleotide homology in HGV E region were 81. 5%.82. 8% 84. 5%.95. 8% comparing with 4 reported HGV isolates (U44402.U45966.U36380.U75356) over the 768 nucleotides examined. And 87. 7%. 91. 5% 94.1% 95. 8% homology with 4 published isolates were found in the amino acid sequences. Conclusion It showed that coinfection of HGV and HCV is confirmed ,there was higher homology with U75356 isolates from China than with U44402 and U45966 isolates from America and U36380 isolates from west-Africa. Nucleic acid homologys were more than amino acid homologys deduced from nucleic acid sequences. The genetic variability of HGV envelope region gene was higher than nonstructral (NS3 NS5) regions and 5' untranslated region (5' UTR).