ENHANCED REPLICATION OF A HEPATITIS-B VIRUS MUTANT ASSOCIATED WITH AN EPIDEMIC OF FULMINANT-HEPATITIS
ENHANCED REPLICATION OF A HEPATITIS-B VIRUS MUTANT ASSOCIATED WITH AN EPIDEMIC OF FULMINANT-HEPATITIS
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DOI：
10.1128/jvi.68.3.1651-1659.1994
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发表时间：
1994-03-01
影响因子：
5.4
通讯作者：
LIANG, TJ
中科院分区：
文献类型：
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作者：
HASEGAWA, K;HUANG, JK;LIANG, TJ
不能合成HBV e抗原的B型肝炎病毒（HBV）突变体与暴发性肝炎有关。我们已经克隆并测序了与暴发性肝炎流行相关的HBV毒株的整个病毒基因组。除了前C区（核苷酸1898和1901）中的两个G-至-A突变外，该菌株还包含保守核苷酸位置中的许多其他突变，导致HBV基因产物中的显著氨基酸取代。我们引入了一个或两个G-到-A突变到野生型HBV的谷胱甘肽定向诱变，并产生这些突变体以及暴发株的复制能力的建设。转染人肝癌细胞后分析病毒抗原合成、转录和复制。所有病毒构建体产生并分泌相似水平的包膜蛋白（HBV表面抗原）。核心特异性免疫反应性的细胞裂解物分析表明，在用暴发菌株转染的细胞中，核心相关抗原的水平高得多。虽然突变型和野生型HBV DNA转染的细胞合成相似水平的病毒RNA，暴发株指导的核心相关的复制中间体（以及病毒粒子颗粒）比野生型和突变体与一个或两个前核心突变高得多的水平的合成。前基因组RNA进入核心颗粒的增加可能是与暴发菌株相关的增强复制的基础。我们的研究表明，增强病毒复制的HBV突变可能在暴发性肝功能衰竭的发病机制中很重要，而前C区突变以外的突变可能是导致这种变异行为的原因。
Hepatitis B virus (HBV) mutants unable to synthesize HBV e antigen have been described in association with fulminant hepatitis. We have cloned and sequenced the entire viral genome of an HBV strain associated with an epidemic of fulminant hepatitis. This strain contained, in addition to two G-to-A mutations in the precore region (nucleotides 1898 and 1901), numerous other mutations in conserved nucleotide positions resulting in significant amino acid substitutions in HBV gene products. We introduced either or both of the two G-to-A mutations into wild-type HBV by oligonucleotide-directed mutagenesis and generated replication-competent constructs of these mutants as well as the fulminant strain. Viral antigen synthesis, transcription, and replication were analyzed after transfection into human hepatoma cells. All viral constructs produced and secreted similar levels of envelope proteins (HBV surface antigen). Analysis of cellular lysate for core-specific immunoreactivity demonstrated a much higher level of core-associated antigens in cells transfected with the fulminant strain. While cells transfected with mutant and wild-type HBV DNAs synthesized similar levels of viral RNAs, the fulminant strain directed the synthesis of a much higher level of core-associated replicative intermediates (as well as virion particles) than the wild type and mutants with either or both of the precore mutations. Increase in the encapsidation of pregenomic RNA into core particles is likely the basis for the enhanced replication associated with the fulminant strain. Our study suggests that an HBV mutant with enhanced viral replication may be important in the pathogenesis of fulminant hepatic failure, and mutations other than the precore mutations may be responsible for this variant behavior.