Sells M A, Chen M L, Acs G
Proc Natl Acad Sci U S A. 1987 Feb;84(4):1005-9. doi: 10.1073/pnas.84.4.1005.
The hepatoblastoma cell line Hep G2 was transfected with a plasmid carrying the gene that confers resistance to G418 and four 5'-3' tandem copies of the hepatitis B virus (HBV) genome positioned such that two dimers of the genomic DNA are 3'-3' with respect to one another. Cells of one clone that grew in the presence of G418 produce high levels of hepatitis B e antigen and of hepatitis B surface antigen. HBV DNA is carried by these cells as chromosomally integrated sequences and episomally as relaxed circular, covalently closed, and incomplete copies of the HBV genome. Viral DNA was detected also in conditioned growth medium at the buoyant densities characteristic for infectious Dane and immature core particles. Finally, HBV-specific components morphologically identical to the 22-nm spherical and filamentous hepatitis B surface antigen particles as well as 42-nm Dane particles were visualized by immunoelectron microscopic analysis. Therefore, we have demonstrated that the Hep G2 cell line can support the assembly and secretion not only of several of the replicative intermediates of HBV DNA but also of Dane-like particles. This in vitro system can now be used to study the life cycle of HBV and the reaction of immunocompetent cells with cells carrying HBV.
将携带对G418具有抗性的基因以及四个5'-3'串联拷贝的乙型肝炎病毒（HBV）基因组的质粒转染至肝癌细胞系Hep G2，这些基因组DNA的两个二聚体彼此呈3'-3'排列。在含有G418的培养基中生长的一个克隆的细胞产生高水平的乙型肝炎e抗原和乙型肝炎表面抗原。这些细胞携带的HBV DNA以染色体整合序列的形式存在，同时也以松弛环状、共价闭合且不完整的HBV基因组拷贝的形式以附加体的形式存在。在条件生长培养基中也检测到了病毒DNA，其浮力密度具有传染性丹氏颗粒和未成熟核心颗粒的特征。最后，通过免疫电子显微镜分析观察到了形态上与22纳米球形和丝状乙型肝炎表面抗原颗粒以及42纳米丹氏颗粒相同的HBV特异性成分。因此，我们证明了Hep G2细胞系不仅能够支持HBV DNA的几种复制中间体的组装和分泌，还能支持类丹氏颗粒的组装和分泌。这个体外系统现在可用于研究HBV的生命周期以及免疫活性细胞与携带HBV的细胞之间的反应。
