Enhancement of hepatitis B virus replication by the regulatory X protein in vitro and in vivo
Enhancement of hepatitis B virus replication by the regulatory X protein in vitro and in vivo
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DOI：
10.1128/jvi.02020-06
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发表时间：
2007-03-01
影响因子：
5.4
通讯作者：
Slagle, Betty L.
中科院分区：
文献类型：
--
作者：
Keasler, Victor V.;Hodgson, Amanda J.;Slagle, Betty L.
B型肝炎病毒（HBV）基因组编码一种称为HBx的单一调节蛋白。虽然HBx在细胞培养中有多种功能，但其在病毒复制中的作用仍不明确。在本研究中，我们结合HBV质粒复制试验和尾静脉注射模型来研究HBx在体内的功能。使用长度大于单位的HBV质粒DNA构建体（payw1.2 * 7）和在HBx开放阅读框的第7位具有终止密码子的类似构建体（payw1.2*7），我们发现在没有HBx的情况下，转染的HepG2细胞中HBV复制减少65%。然后通过流体动力学尾静脉注射将这些质粒引入远交ICR小鼠的肝脏中。在病毒复制的高峰期，在注射后4天，与接受野生型payw1.2的小鼠相比，注射HBx缺陷型payw1.2*7的小鼠中HBV复制的肝内标志物降低了72%至83%。编码HBx的第二个质粒能够将病毒复制从payw1.2*7恢复到野生型水平。最后，在急性病毒复制过程中监测病毒血症，在注射后4天，在没有HBx的情况下，病毒血症减少了近2个对数。这些研究表明，HBx在病毒复制中的作用，以前在转染的HepG2细胞中显示，在急性肝炎的情况下，在小鼠肝脏中也是明显的。重要的是，HBx的功能现在可以在更接近HBV复制的细胞环境的体内环境中进行研究。
The 3.2-kb hepatitis B virus (HBV) genome encodes a single regulatory protein termed HBx. While multiple functions have been identified for HBx in cell culture, its role in virus replication remains undefined. In the present study, we combined an HBV plasmid-based replication assay with the hydrodynamic tail vein injection model to investigate the function(s) of HBx in vivo. Using a greater-than-unit-length HBV plasmid DNA construct (payw1.2) and a similar construct with a stop codon at position 7 of the HBx open reading frame (payw1.2*7), we showed that HBV replication in transfected HepG2 cells was reduced 65% in the absence of HBx. These plasmids were next introduced into the livers of outbred ICR mice via hydrodynamic tail vein injection. At the peak of virus replication, at 4 days postinjection, intrahepatic markers of HBV replication were reduced 72% to 83% in mice injected with HBx-deficient payw1.2*7 compared to those measured in mice receiving wild-type payw1.2. A second plasmid encoding HBx was able to restore virus replication from payw1.2*7 to wild-type levels. Finally, viremia was monitored over the course of acute virus replication, and at 4 days postinjection, it was reduced by nearly 2 logs in the absence of HBx. These studies establish that the role for HBx in virus replication previously shown in transfected HepG2 cells is also apparent in the mouse liver within the context of acute hepatitis. Importantly, the function of HBx can now be studied in an in vivo setting that more closely approximates the cellular environment for HBV replication.