乙型肝炎病毒前C/C基因准种与变异特点的研究

THE STUDY ON QUASISPECIES OF HEPATITIS B VIRUS : PRE-CORE/CORE GENE AS AN EXAMPLE

以乙型肝炎病毒 (HBV)前C/C基因异质性来探讨在慢性感染者体内是否存在HBV准种。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例慢性HBV感染患者血清中扩增HBV前C/C基因序列 ,克隆入pGEMTeasy载体 ,每例患者挑选 5个克隆测序以比较病毒的变异程度。测序结果发现同一患者前C/C基因碱基序列之间的同源性大于 98% ,但存有G83→A替换、C抗原内部缺失、移框突变等多种变异类型。结果提示 ,HBV长期携带者体内有HBV准种共存 ,推测前C/C区的多种变异可能与感染慢性化有关。

To investigate the HBV quasispecies groups in the patients with chronic HBV infection. A set of specific primers was synthesized according to HBV DNA sequence of the Chinese strain, and the whole pre core/core region was amplified by PCR method from the serum of 4 patients with chronic HBV infection.Then the PCR products were subcloned into pGEM Teasy vectors. Clones were selected to be sequenced,and then sequence comparison was made to find the difference. Each sequence of selected clones was found to be different. The homology of the nucleic acid sequence from the same patient was above 98 0%. There were many mutation types in this region, including point substitution, core region internal deletion, as well as frame shift reading. The results indicated that there were HBV quasispecies groups in chronically infected patients. The mutation in this region may influence the prognosis of HBV infection.