慢性乙肝患者HBV核心蛋白启动子变异的初步研究

目的　通过对乙型肝炎病毒 (HBV)基本核心基因启动子 (BCP)变异的研究 ,阐明HBV准种在慢性感染者中存在的意义。方法　以中国株HBV基因序列为依据 ,设计特异性多聚酶链反应 (PCR)引物 ,自 4 0例慢性HBV感染患者血清中扩增HBV的BCP基因 ,采用聚丙烯酰胺凝胶电泳 (PAGE)技术展示缺失突变 ,DNA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 ,6 0 % (2 4 / 4 0 )患者血清中可见 2～ 3条扩增条带 ;测序结果发现BCP区存在多种突变形式 :点突变中以 14 0nt(T→C)最为常见 ,缺失突变多见于TA1,TA2及TA3,多表现为 8bp和 2 0bp的缺失。 结论　HBVBCP区内有一缺失高变区 ,并在患者体内存有多种变异形式 ;TA1,TA2和TA3的变异可能影响e抗原的表达。HBV慢性携带者体内有HBV准种共存

The primary study on variation in the basic core promoter of the hepatitis B virus on the patients with chronic hepatitis B

Objective To investigate the variation of the basic core promoter(BCP) of HBV and clarify the significance of HBV quasispecies groups in the patients with chronic HBV. Methods A set of specific primers was synthesized according to HBV DNA sequence of Chinese strain. The BCP was amplified by PCR from the sample serum of 40 patients with chronic HBV, and the PCR products of 5 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel electrophoresis(PAGE) was employed to display the deletion variant, clones with different length were selected for sequencing. Sequencing results were analyzed. Results 2～3 bands were displayed by PAGE in 60% patients. The results of sequence analysis showed there were some kinds of variation in BCP region. The substitution always occurs in TATA like boxes, especially from T to C on nt140 site. The deletion variations were detected in TA1, TA2 and TA3. The 8?bp, 20?bp deletion variations frequently happened. Conclusion There is a hot deletion region in BCP. The deletion and the substitution in the TATA like box may influence the expression of pre C/C protein. The sequencing results imply that there are HBV quasispecies groups in patients with chronic HBV infection.