The Envelope Gene of Hepatitis B Virus Is Implicated in Both Differential Virion Secretion and Genome Replication Capacities between Genotype B and Genotype C Isolates.
The Envelope Gene of Hepatitis B Virus Is Implicated in Both Differential Virion Secretion and Genome Replication Capacities between Genotype B and Genotype C Isolates.
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乙型肝炎病毒的包膜基因与 B 基因型和 C 基因型分离株之间病毒颗粒分泌和基因组复制能力的差异有关
DOI：
10.3390/v9040062
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发表时间：
2017-03-28
期刊：
影响因子：
--
通讯作者：
Tong S
中科院分区：
文献类型：
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作者：
Jia H;Qin Y;Chen C;Zhang F;Li C;Zong L;Wang Y;Zhang J;Li J;Wen Y;Tong S
与基因型B感染相比，慢性感染B型肝炎病毒（HBV）C基因型与复制期延长和肝癌风险增加相关。我们以前发现较低的复制能力，但更有效的病毒粒子分泌基因型C比基因型B分离。病毒体分泌需要核心颗粒和ENVEGFPPE蛋白之间的相互作用。在本研究中，产生基因型B和基因型C克隆之间的嵌合构建体以鉴定差异病毒体分泌的结构基础。除了二聚体构建体，我们还采用了1.1聚体构建体，其中巨细胞病毒（CMV）启动子驱动前基因组RNA转录。通过Huh 7细胞中的瞬时转染实验，我们发现交换整个包膜基因或仅交换其S区可以增强基因型B克隆的病毒体分泌，而减少基因型C的病毒体分泌。定点诱变建立了基因型特异性差异的贡献，在密码子108和115在前S1区，以及密码子126在S区，差异病毒体分泌。令人惊讶的是，交换包膜基因或仅其S区，而不是核心基因或3′ S区，可以显著增加基因型C克隆的细胞内复制DNA，但减少基因型B的细胞内复制DNA，尽管潜在的机制仍有待澄清。
Chronic infection by hepatitis B virus (HBV) genotype C is associated with a prolonged replicative phase and an increased risk of liver cancer, compared with genotype B infection. We previously found lower replication capacity but more efficient virion secretion by genotype C than genotype B isolates. Virion secretion requires interaction between core particles and ENVELOPE proteins. In the present study, chimeric constructs between genotype B and genotype C clones were generated to identify the structural basis for differential virion secretion. In addition to dimeric constructs, we also employed 1.1mer constructs, where the cytomegalovirus (CMV) promoter drove pregenomic RNA transcription. Through transient transfection experiments in Huh7 cells, we found that exchanging the entire envelope gene or just its S region could enhance virion secretion by genotype B clones while diminishing virion secretion by genotype C. Site-directed mutagenesis established the contribution of genotype-specific divergence at codons 108 and 115 in the preS1 region, as well as codon 126 in the S region, to differential virion secretion. Surprisingly, exchanging the envelope gene or just its S region, but not the core gene or 3′ S region, could markedly increase intracellular replicative DNA for genotype C clones but diminish that for genotype B, although the underlying mechanism remains to be clarified.