摘要
目的 通过对乙型肝炎病毒 (HBV)前S2基因序列的研究 ,证实HBV在慢性感染者中以准种状态存在 ,并对前S2序列异质性进行初步的阐明。方法 以中国株HBV基因序列为依据 ,设计特异性PCR引物 ,自 5 1例慢性HBV感染患者血清中扩增HBV前S2基因序列 ,采用聚丙烯酰胺凝胶电泳技术展示缺失突变 ,随机选择克隆测序 ,确定病毒的变异程度。结果 聚丙烯酰胺凝胶电泳结果发现 ,5 2 9% (2 7/ 5 1)患者血清中可获得 2或 3条扩增条带 ;测序结果发现前S2基因序列存在缺失突变高发区 ,氨基酸序列分析示缺失突变主要位于前S2编码蛋白的氨基端。结论 HBV前S2序列内有一缺失高变区 ,并在患者体内表现为多种变异形式 ;氨基端附近的变异可能影响中和抗体的识别作用。结果提示HBV慢性携带者体内有HBV准种共存。
Objective To investigate the mutation of the preS2 gene sequence of HBV and clarify the significance of HBV quasispecies groups in the patients with chronic HBV infection. Methods A set of specific primers were synthesized according to HBV DNA sequence of a Chinese strain. The preS2 gene region was amplified by PCR method from the sera of 51 patients with chronic HBV infection, and the PCR products from 5 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis(PAGE) was employed to display the deletion mutations, clones with differential length were selected and sequenced. Sequence comparison was made to find the difference. Results When analyzed by PAGE, 2～3 bands were displayed in the PCR products from 52.9%(27/51) patients. This phenomena of multiple bands in PAGE was detected in both HBeAg(36.1%) and anti HBe(93.3%) positive patients, the difference between the 2 groups being statistically significant ( P <0.01). Analysis on deduced amino acid sequence showed the deletion mutations were in the N terminal half of the preS2 encoded protein.Conclusion There is a hot deletion region in preS2 gene sequence. These deletion mutations were more frequently found in patients with both anti HBe and HBV DNA positivity. The deletion may influence the recognition by neutralizing antibodies. Our results suggest that there are HBV quasispecies in patients with chronic HBV infection.
出处
《中华内科杂志》
CAS
CSCD
北大核心
2002年第4期233-236,共4页
Chinese Journal of Internal Medicine
