Liver Research Unit, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Keelung, Taiwan.
PLoS One. 2013 May 29;8(5):e65456. doi: 10.1371/journal.pone.0065456. Print 2013.
Occult hepatitis B virus (HBV) infection is defined as persistence of HBV DNA in liver tissues, with or without detectability of HBV DNA in the serum, in individuals with negative serum HBV surface antigen (HBsAg). Despite accumulating evidence suggesting its important clinical roles, the molecular and virological basis of occult hepatitis B remains unclear. In an attempt to establish new hepatoma cell lines, we achieved a new cell line derived from a hepatoma patient with chronic hepatitis C virus (HCV) and occult HBV infection. Characterization of this cell line revealed previously unrecognized properties. Two novel human hepatoma cell lines were established. Hep-Y1 was derived from a male hepatoma patient negative for HCV and HBV infection. Hep-Y2 was derived from a female hepatoma patient suffering from chronic HCV and occult HBV infection. Morphological, cytogenetic and functional studies were performed. Permissiveness to HBV infection was assessed. Both cell lines showed typical hepatocyte-like morphology under phase-contrast and electron microscopy and expressed alpha-fetoprotein, albumin, transferrin, and aldolase B. Cytogenetic analysis revealed extensive chromosomal anomalies. An extrachromosomal form of HBV DNA persisted in the nuclear fraction of Hep-Y2 cells, while no HBsAg was detected in the medium. After treated with 2% dimethyl sulfoxide, both cell lines were permissive for exogenous HBV infection with transient elevation of the replication intermediates in the cytosol with detectable viral antigens by immunoflurescence analysis. In conclusions, we established two new hepatoma cell lines including one from occult HBV infection (Hep-Y2). Both cell lines were permissive for HBV infection. Additionally, Hep-Y2 cells carried persistent extrachromosomal HBV DNA in the nuclei. This cell line could serve as a useful tool to establish the molecular and virological basis of occult HBV infection.
隐匿性乙型肝炎病毒 (HBV) 感染定义为血清 HBV 表面抗原 (HBsAg) 阴性个体的肝组织中存在 HBV DNA 持续存在，无论血清中是否可检测到 HBV DNA。尽管有越来越多的证据表明其具有重要的临床作用，但隐匿性乙型肝炎的分子和病毒学基础仍不清楚。为了建立新的肝癌细胞系，我们成功地从一名患有慢性丙型肝炎病毒 (HCV) 和隐匿性 HBV 感染的肝癌患者中获得了一个新的细胞系。该细胞系的特征表明了以前未被认识到的特性。建立了两个新的人肝癌细胞系。Hep-Y1 源自一名 HCV 和 HBV 感染均为阴性的男性肝癌患者。Hep-Y2 源自一名患有慢性 HCV 和隐匿性 HBV 感染的女性肝癌患者。进行了形态学、细胞遗传学和功能研究。评估了对 HBV 感染的易感性。在相差和电子显微镜下，两种细胞系均表现出典型的肝细胞样形态，并表达甲胎蛋白、白蛋白、转铁蛋白和醛缩酶 B。细胞遗传学分析显示广泛的染色体异常。Hep-Y2 细胞的核部分持续存在 HBV DNA 的染色体外形式，而培养基中未检测到 HBsAg。用 2%二甲基亚砜处理后，两种细胞系均允许外源性 HBV 感染，细胞质中的复制中间体短暂升高，免疫荧光分析可检测到病毒抗原。总之，我们建立了两个新的肝癌细胞系，包括一个来自隐匿性 HBV 感染的细胞系 (Hep-Y2)。两种细胞系均允许 HBV 感染。此外，Hep-Y2 细胞的核内携带持续存在的染色体外 HBV DNA。该细胞系可作为建立隐匿性 HBV 感染分子和病毒学基础的有用工具。
