The sodium taurocholate cotransporting polypeptide (NTCP) is a functional receptor for hepatitis B virus (HBV). NTCP-reconstituted human hepatoma cells support HBV infection, but the infection is suboptimal and no apparent HBV spread has been observed in this system. We found that NTCP-reconstituted HepG2 cells were highly susceptible to HBV infection after cells were cultured in a commercial human inducible pluripotent stem cell (iPSC)-derived hepatocyte maintenance medium (HMM). The enhanced HBV infection coincided with increased NTCP expression, and was observed in six different clones of HepG2-NTCP cells. Promoter assays indicated that HMM activated the cytomegalovirus immediate-early (IE) promoter that drives the NTCP expression in the HepG2-NTCP cells. RNA-Seq analysis revealed that HMM upregulated multiple metabolic pathways. Despite highly upregulated NTCP expression by HMM, no obvious HBV spread was observed even in the presence of PEG 8000. Our data suggest that this particular medium could be used to enhance HBV infection in NTCP-reconstituted hepatocytes in vitro.

中文翻译：

---

iPSC 衍生的人肝细胞维持培养基提高 NTCP 表达可增强 NTCP 重建的 HepG2 细胞中的 HBV 感染


牛磺胆酸钠共转运多肽 (NTCP) 是乙型肝炎病毒 (HBV) 的功能性受体。 NTCP 重建的人肝癌细胞支持 HBV 感染，但感染不是最理想的，并且在该系统中没有观察到明显的 HBV 传播。我们发现，NTCP 重建的 HepG2 细胞在商业人类诱导多能干细胞 (iPSC) 衍生的肝细胞维持培养基 (HMM) 中培养后，对 HBV 感染高度敏感。 HBV 感染增强与 NTCP 表达增加同时发生，并且在 HepG2-NTCP 细胞的六个不同克隆中观察到。启动子测定表明，HMM 激活了巨细胞病毒立即早期 (IE) 启动子，该启动子驱动 HepG2-NTCP 细胞中的 NTCP 表达。 RNA-Seq 分析表明，HMM 上调了多种代谢途径。尽管 HMM 高度上调 NTCP 表达，但即使在 PEG 8000 存在的情况下，也没有观察到明显的 HBV 扩散。我们的数据表明，这种特殊的介质可用于在体外增强 NTCP 重建肝细胞中的 HBV 感染。