乙型肝炎病毒共价闭合环状DNA形成的永生化小鼠肝细胞伴有

StephenW

Hepatitis B Virus Covalently Closed Circular DNA Formation in Immortalized Mouse Hepatocytes Associated with Nucleocapsid                  Destabilization                                                

• Xiuji Cuia,
• Ju-Tao Guob and
• Jianming Hua
  

                  

• aDepartment of Microbiology and Immunology, Penn State University College of Medicine, Hershey, Pennsylvania, USA
• bDepartment of Experimental Therapeutics, Baruch S. Blumberg Institute, Doylestown, Pennsylvania, USA
  

               
                                 

• G. McFadden, Editor
  

ABSTRACT

Hepatitis B virus (HBV) infects hundreds of millions of people worldwide and causes acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HBV is an enveloped virus with a relaxed circular (RC) DNA genome. In the nuclei of infected human hepatocytes, conversion of RC DNA from the incoming virion or cytoplasmic mature nucleocapsid (NC) to the covalently closed circular (CCC) DNA, which serves as the template for producing all viral transcripts, is essential to establish and sustain viral replication. For reasons yet to be understood, HBV is apparently unable to make CCC DNA in normal mouse hepatocytes in the liver. We report here that HBV CCC DNA was formed efficiently in an immortalized mouse hepatocyte cell line, AML12HBV10, and this is associated with destabilization of mature NCs in these cells. These results suggest that destabilization of mature HBV NCs in AML12HBV10 cells facilitates efficient NC uncoating and subsequent CCC DNA formation. They further implicate NC uncoating as an important step in CCC DNA formation that is subject to host regulation and potentially a critical determinant of host range and/or cell tropism of HBV.

IMPORTANCE Persistent infection by hepatitis B virus (HBV), afflicting hundreds of millions worldwide, is sustained by the episomal viral covalently closed circular (CCC) DNA in the nuclei of infected hepatocytes. CCC DNA is converted from the viral genomic (precursor) DNA contained in cytoplasmic viral nucleocapsids. The conversion process remains ill defined, but host cell factors are thought to play an essential role. In particular, HBV fails to make CCC DNA in normal mouse hepatocytes despite the presence of large amounts of nucleocapsids containing the precursor viral DNA. We have found that in an immortalized mouse hepatocyte cell line, HBV is able to make abundant amounts of CCC DNA. This ability correlates with increased instability of viral nucleocapsids in these cells, which likely facilitates nucleocapsid disassembly (uncoating) to release the genomic DNA for conversion to CCC DNA. Our studies have thus revealed a novel mechanism of controlling viral persistence via regulating nucleocapsid disassembly.                        
                                 FOOTNOTES                  

• Received 14 May 2015.
• Accepted 11 June 2015.
• Accepted manuscript posted online 17 June 2015.
  
• Address correspondence to Jianming Hu, [email protected].
  

StephenW

乙型肝炎病毒共价闭合环状DNA形成的永生化小鼠肝细胞伴有核衣壳失稳

    修己Cuia，鞠涛Guob和华建明

    微生物学与免疫学，医学宾夕法尼亚州立大学，贺喜，宾夕法尼亚州，美国aDepartment
    实验治疗，巴鲁克S. Blumberg的学院，宾夕法尼亚州Doylestown，美国bDepartment

    G.麦克法登，编辑器

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作者机构
摘要

乙型肝炎病毒（HBV）感染数亿全世界人民和引起急性和慢性肝炎，肝硬化和肝细胞癌。乙肝病毒是一种包膜病毒与轻松的圆（RC）的DNA基因组。在被感染的人肝细胞，从传入病毒体或细胞质成熟核衣壳（NC）的转化的RC的DNA的共价闭合环状（CCC）的DNA，作为模板用于产生所有病毒转录物的核，必须建立和维持病毒复制。为原因，可以理解，HBV是显然无法使CCC的DNA在正常小鼠肝细胞在肝脏中。我们这里报告的HBV CCC的DNA在永生化小鼠肝细胞细胞系，AML12HBV10形成有效的，这与在这些细胞中成熟NC的不稳定有关。这些结果表明，成熟的HBV NC的在AML12HBV10细胞不稳定便于有效的NC脱壳和随后CCC DNA的形成。他们还牵连NC脱壳作为CCC DNA形成的一个重要步骤，是受监管主机和主机范围和/或乙肝病毒的细胞嗜潜在的一个关键因素。

重要性持续感染乙型肝炎病毒（HBV），困扰全世界数以百万计，是由附加型持续病毒共价闭合环状（CCC）的DNA在感染的肝细胞的细胞核中。 CCC DNA从病毒基因组（前体）中包含的细胞质病毒核衣壳的DNA转化。转换过程仍然不明确，但宿主细胞因子被认为是发挥了至关重要的作用。具体地，HBV的失败使CCC的DNA在正常小鼠肝细胞，尽管大量含有所述前体的病毒DNA的核衣壳的存在。我们已发现，在永生化小鼠肝细胞细胞系，乙肝病毒是能够使CCC DNA的丰量。这种能力相关病毒核衣壳在这些细胞中增加的不稳定性，这可能有利于核壳拆装（脱壳​​）释放用于转换至CCC DNA中的基因组DNA。因此，我们的研究揭示了一种新的通过调节核壳拆卸控制病毒持续感染的机制。
脚注

        收到2015年5月14日。
        接受2015年6月11日。
        接受手稿在网上发布17 2015年6月。
    通信地址建明胡，[email protected]。