Department of Microbiology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA.
National Institute of Biological Sciences, Beijing, China.
J Virol. 2018 Nov 12;92(23). doi: 10.1128/JVI.01255-18. Print 2018 Dec 1.
Hepatitis B virus (HBV) is a major cause of chronic liver diseases, including hepatitis, cirrhosis, and hepatocellular carcinoma. HBV research has been hampered by the lack of robust cell culture and small animal models of HBV infection. The discovery of sodium taurocholate cotransporting polypeptide (NTCP) as an HBV receptor has been a landmark advance in HBV research in recent years. Ectopic expression of NTCP in nonpermissive HepG2, Huh7, and AML12 cell lines confers HBV susceptibility. However, HBV replication in these human and murine hepatocyte cell lines appeared suboptimal. In the present study, we constructed stable NTCP-expressing HepG2 and AML12 cell lines and found that HBV permissiveness is correlated with NTCP expression. More significantly, we developed robust HBV cell culture models by treating the HBV-infected cells with dimethyl sulfoxide (DMSO) and hydrocortisone, which significantly promoted HBV replication and production. Mechanistic studies suggested that hydrocortisone significantly enhanced the transcription and expression of PGC1α and HNF4α, which are known to promote HBV transcription and replication. These new human and murine hepatocyte culture systems of HBV infection and replication will accelerate the determination of molecular aspects underlying HBV infection, replication, and morphogenesis in human and murine hepatocytes. We anticipate that our HBV cell culture models will also facilitate the discovery and development of antiviral drugs towards the ultimate eradication of chronic hepatitis B virus infection. HBV research has been greatly hampered by the lack of robust cell culture and small animal models of HBV infection and propagation. The discovery of NTCP as an HBV receptor has greatly impacted the field of HBV research. Although HBV infection of NTCP-expressing human and murine hepatocyte cell lines has been demonstrated, its replication in cell culture appeared inefficient. To further improve cell culture systems of HBV infection and replication, we constructed NTCP-expressing HepG2 and AML12 cell lines that are highly permissive to HBV infection. More significantly, we found that DMSO and hydrocortisone markedly enhanced HBV transcription and replication in human and murine hepatocytes when added to the cell culture medium. These new cell culture models of HBV infection and replication will facilitate HBV research and antiviral drug discovery towards the ultimate elimination of chronic hepatitis B virus infection.
乙型肝炎病毒（HBV）是导致慢性肝病的主要原因之一，包括肝炎、肝硬化和肝细胞癌。HBV 研究受到缺乏强大的细胞培养和 HBV 感染的小动物模型的阻碍。近年来，发现牛磺胆酸钠共转运蛋白（NTCP）作为 HBV 受体是 HBV 研究的一个里程碑式的进展。在非允许的 HepG2、Huh7 和 AML12 细胞系中外源表达 NTCP 赋予了 HBV 的易感性。然而，这些人源和鼠源肝细胞系中的 HBV 复制似乎并不理想。在本研究中，我们构建了稳定表达 NTCP 的 HepG2 和 AML12 细胞系，发现 HBV 的易感性与 NTCP 的表达相关。更重要的是，我们通过用二甲基亚砜（DMSO）和氢化可的松处理 HBV 感染的细胞，开发了强大的 HBV 细胞培养模型，这显著促进了 HBV 的复制和产生。机制研究表明，氢化可的松显著增强了 PGC1α 和 HNF4α 的转录和表达，已知这两种蛋白可促进 HBV 的转录和复制。这些新的 HBV 感染和复制的人源和鼠源肝细胞培养系统将加速确定 HBV 在人源和鼠源肝细胞中感染、复制和形态发生的分子方面。我们预计，我们的 HBV 细胞培养模型也将有助于发现和开发抗病毒药物，以最终消除慢性乙型肝炎病毒感染。HBV 研究受到缺乏强大的细胞培养和 HBV 感染和传播的小动物模型的严重阻碍。NTCP 作为 HBV 受体的发现极大地推动了 HBV 研究领域的发展。尽管已经证明了 NTCP 表达的人源和鼠源肝细胞系中 HBV 的感染，但在细胞培养中其复制效率较低。为了进一步改进 HBV 感染和复制的细胞培养系统，我们构建了高度允许 HBV 感染的表达 NTCP 的 HepG2 和 AML12 细胞系。更重要的是，我们发现当添加到细胞培养基中时，DMSO 和氢化可的松显著增强了人源和鼠源肝细胞中的 HBV 转录和复制。这些新的 HBV 感染和复制的细胞培养模型将促进 HBV 研究和抗病毒药物的发现，以最终消除慢性乙型肝炎病毒感染。
