Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan; Laboratory of Regulatory Sciences for Oligonucleotide Therapeutics, Clinical Drug Development Unit, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
Virus Res. 2017 Oct 15;242:7-15. doi: 10.1016/j.virusres.2017.09.004. Epub 2017 Sep 9.
Hepatitis C virus (HCV) infection is a major cause of liver-related morbidity and mortality. In order to develop effective remedies for hepatitis C, it is important to understand the HCV infection profile and host-HCV interaction. HCV-induced innate immune responses play a crucial role in spontaneous HCV clearance; however, HCV-induced innate immune responses have not been fully evaluated in hepatocytes, partly because there are few in vitro models of HCV-induced innate immunity. Recently, human induced pluripotent stem (iPS) cells have received much attention as an in vitro model of infection with various pathogens, including HCV. We previously established highly functional hepatocyte-like cells differentiated from human iPS cells (iPS-HLCs). Here, we examined the potential of iPS-HLCs as an in vitro HCV infection model, especially for evaluation of the relationship between HCV infection levels and HCV-induced innate immunity. Significant expressions of type I and III interferons (IFNs) and IFN-stimulated genes (ISGs) were induced following transfection with HCV genomic replicon RNA in iPS-HLCs. Following inoculation with the HCV JFH-1 strain in iPS-HLCs, peaks of HCV genome replication and HCV protein expression were observed on day 2, and then both the HCV genome and protein levels gradually declined, while the mRNA levels of type III IFNs and ISGs peaked at day 2 following inoculation. These results suggest that the HCV genome efficiently replicates in iPS-HLCs, resulting in HCV genome-induced up-regulation of IFNs and ISGs, and thereafter, HCV genome-induced up-regulation of IFNs and ISGs mediates a reduction in the HCV genome and protein levels in iPS-HLCs.
丙型肝炎病毒 (HCV) 感染是导致肝脏相关发病率和死亡率的主要原因。为了开发有效的丙型肝炎治疗方法，了解 HCV 感染谱和宿主 - HCV 相互作用非常重要。HCV 诱导的固有免疫反应在自发性 HCV 清除中起着至关重要的作用；然而，HCV 诱导的固有免疫反应在肝细胞中尚未得到充分评估，部分原因是 HCV 诱导的固有免疫的体外模型较少。最近，人类诱导多能干细胞 (iPS) 作为感染各种病原体（包括 HCV）的体外模型受到了广泛关注。我们之前已经建立了从人 iPS 细胞分化而来的具有高度功能的肝细胞样细胞（iPS-HLCs）。在这里，我们研究了 iPS-HLC 作为 HCV 体外感染模型的潜力，特别是用于评估 HCV 感染水平与 HCV 诱导的固有免疫之间的关系。在 iPS-HLC 中转染 HCV 基因组复制子 RNA 后，可诱导 I 型和 III 型干扰素 (IFNs) 和 IFN 刺激基因 (ISGs) 的显著表达。在 iPS-HLC 中接种 HCV JFH-1 株后，在第 2 天观察到 HCV 基因组复制和 HCV 蛋白表达的峰值，然后 HCV 基因组和蛋白水平逐渐下降，而 III 型 IFNs 和 ISGs 的 mRNA 水平在接种后第 2 天达到峰值。这些结果表明 HCV 基因组在 iPS-HLC 中有效地复制，导致 HCV 基因组诱导的 IFN 和 ISGs 上调，随后 HCV 基因组诱导的 IFN 和 ISGs 上调介导 HCV 基因组和蛋白水平在 iPS-HLC 中的降低。
