Mechanism of the dependence of hepatitis B virus genotype G on co-infection with other genotypes for viral replication
Mechanism of the dependence of hepatitis B virus genotype G on co-infection with other genotypes for viral replication
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DOI：
10.1111/jvh.12022
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发表时间：
2013-04-01
影响因子：
2.5
通讯作者：
Mizokami, M.
中科院分区：
文献类型：
--
作者：
Sakamoto, T.;Tanaka, Y.;Mizokami, M.
乙型肝炎病毒（HBV）分为多种基因型。 G 基因型 (HBV/G) 的特点是全球分散、基因型内多样性低以及前核心和核心区域的特殊序列（终止密码子和 36 个核苷酸插入）。一般来说，HBV/G 是在与另一种基因型（最常见的是 HBV/A2）同时感染时检测到的。在之前的体内研究中，与 HBV/A2 共感染显着增强了 HBV/G 的病毒复制。然而，同时感染 HBV/A2 增强 HBV/G 复制的机制尚不完全清楚。在这项研究中，我们采用了 1.24 倍的 HBV/A2 克隆来选择性表达每种病毒蛋白，并发现核心蛋白表达构建体显着增强了 Huh7 细胞中 HBV/G 的复制。将HBV/A2核心启动子或核心蛋白或两个基因组区域引入HBV/G基因组表明，核心启动子和核心蛋白都是有效的HBV/G复制所必需的。基因型对外源核心蛋白与HBV/G相互作用的影响表明，HBV/A2是HBV/G复制的最强增强子。此外，对从 HBV/G 和巨细胞病毒 (CMV) 启动子驱动的 HBV/A2 核心蛋白表达构建体共转染的 Huh7 细胞培养物中分离出的 Dane 颗粒进行蛋白质印迹分析，表明 HBV/G 在颗粒组装过程中使用了 HBV/A2 核心蛋白。总之，HBV/G 在共感染过程中可以利用其他基因型的核心蛋白进行高效复制，并将 HBV DNA 有效包装到病毒粒子中。
Hepatitis B virus (HBV) is classified into several genotypes. Genotype G (HBV/G) is characterised by worldwide dispersion, low intragenotypic diversity and a peculiar sequence of the precore and core region (stop codon and 36-nucleotide insertion). As a rule, HBV/G is detected in co-infection with another genotype, most frequently HBV/A2. In a previous in vivo study, viral replication of HBV/G was significantly enhanced by co-infection with HBV/A2. However, the mechanism by which co-infection with HBV/A2 enhances HBV/G replication is not fully understood. In this study, we employed 1.24-fold HBV/A2 clones that selectively expressed each viral protein and revealed that the core protein expressing construct significantly enhanced the replication of HBV/G in Huh7 cells. The introduction of the HBV/A2 core promoter or core protein or both genomic regions into the HBV/G genome showed that both the core promoter and core protein are required for efficient HBV/G replication. The effect of genotype on the interaction between foreign core protein and HBV/G showed that HBV/A2 was the strongest enhancer of HBV/G replication. Furthermore, Western blot analysis of Dane particles isolated from cultures of Huh7 cells co-transfected by HBV/G and a cytomegalovirus (CMV) promoterdriven HBV/A2 core protein expression construct indicated that HBV/G employed HBV/A2 core protein during particle assembly. In conclusion, HBV/G could take advantage of core proteins from other genotypes during co-infection to replicate efficiently and to effectively package HBV DNA into virions.