Hantz O, Parent R, Durantel D, Gripon P, Guguen-Guillouzo C, Zoulim F
INSERM, U871, 69003 Lyon, France.
J Gen Virol. 2009 Jan;90(Pt 1):127-35. doi: 10.1099/vir.0.004861-0.
The recently described hepatic cell line HepaRG is the sole hepatoma cell line susceptible to hepatitis B virus (HBV) infection. It provides a unique tool for investigating some unresolved issues of the virus' biology, particularly the formation of the viral mini-chromosome believed to be responsible for the persistence of infection. In this study, we characterized the main features of HBV infection: it is restricted to a subpopulation of differentiated hepatocyte-like cells that express albumin as a functional marker and represents around 10 % of all differentiated HepaRG cells. Infection may persist for more than 100 days in cells maintained at the differentiated state. Even though infected cells continued to produce infectious viral particles, very limited or no spreading of infection was observed. Low genetic variation was also observed in the viral DNA from viruses found in the supernatant of infected cells, although this cannot explain the lack of reinfection. HBV infection of HepaRG cells appears to be a very slow process: viral replication starts at around day 8 post-infection and reaches a maximum at day 13. Analysis of viral DNA showed slow and inefficient conversion of the input relaxed circular DNA into covalently closed circular (CCC) DNA, but no further amplification. Continuous lamivudine treatment inhibited viral replication, but neither prevented viral infection nor initial formation of CCC DNA. In conclusion, HBV infection in differentiated HepaRG cells is characterized by long-term persistence without a key feature of hepadnaviruses, the so-called 'CCC DNA amplification' described in the duck hepatitis B model.
最近描述的肝癌细胞系HepaRG是唯一易受乙型肝炎病毒（HBV）感染的肝癌细胞系。它为研究该病毒生物学中一些尚未解决的问题提供了一个独特的工具，特别是与感染持续存在相关的病毒微型染色体的形成。在本研究中，我们对HBV感染的主要特征进行了表征：它仅限于表达白蛋白作为功能标志物的分化肝细胞样细胞亚群，约占所有分化的HepaRG细胞的10%。在维持分化状态的细胞中，感染可能持续超过100天。尽管受感染细胞继续产生有传染性的病毒颗粒，但观察到感染的传播非常有限或没有传播。在受感染细胞上清液中发现的病毒的病毒DNA中也观察到低遗传变异，尽管这无法解释缺乏再感染的原因。HepaRG细胞的HBV感染似乎是一个非常缓慢的过程：病毒复制在感染后约第8天开始，并在第13天达到最大值。病毒DNA分析显示，输入的松弛环状DNA缓慢且低效地转化为共价闭合环状（CCC）DNA，但没有进一步扩增。持续的拉米夫定治疗抑制了病毒复制，但既不能预防病毒感染，也不能阻止CCC DNA的初始形成。总之，分化的HepaRG细胞中的HBV感染的特征是长期持续存在，而没有嗜肝DNA病毒的一个关键特征，即鸭乙型肝炎模型中描述的所谓“CCC DNA扩增”。
