外周血中乙型肝炎病毒截短型囊膜蛋白基因的克隆化与序列分析

Cloning and sequence analysis of truncated S gene from circulation of patients with chronic hepatitis B virus infection

目的研究乙型肝炎病毒（ＨＢＶ）在慢性感染者体内存在的特殊状态。方法采用特异性引物设计，以多聚酶链反应（ＰＣＲ）自患者血清中扩增全Ｓ基因片段，测序以明确变异的部位，并与既往已发表的ＨＢＶ ａｄｒ亚型进行序列比较。结果经测序发现慢性ＨＢＶ感染者体内存有变异病毒株编码的截短型表面抗原中蛋白基因，并存有ＨＢｓＡｓ和多聚酶区缺陷型病毒基因。结论在外周血中存在ＨＢＶ截短型囊膜蛋白编码基因，可能与患者不良预后有关。

Objective To find different mutated status of HBV DNA in circulation from chronic HBV patients. Methods Specially designed primers and polymerase chain reaction method were applied to amplify the whole S gene of HBV from the serum of 2 patients. After being sequenced, 4 clones were compared with HBV adr subtype (China strain) to identify the mutant sites. Results Sequencing results implied that there was a truncated large/middle S gene in the serum of the patients. Besides that, HBsAg and HBV DNA polymerase defective clones were also detected. Conclusions Truncated middle S gene is found in the circulation of patients with chronical HBV infection, suggestive of a poor prognosis.