Evidence that hepatitis B virus replication in mouse cells is limited by the lack of a host cell dependency factor

J Hepatol. 2016 Mar;64(3):556-64. doi: 10.1016/j.jhep.2015.10.030. Epub 2015 Nov 11.


Background & aims: Hepatitis B virus (HBV) is a major human pathogen restricted to hepatocytes. Expression of the specific receptor human sodium taurocholate cotransporting polypeptide (hNTCP) in mouse hepatocytes renders them susceptible to hepatitis delta virus (HDV), a satellite of HBV; however, HBV remains restricted at an early stage of replication. This study aims at clarifying whether this restriction is caused by the lack of a dependency factor or the activity of a restriction factor.

Methods: Six hNTCP-expressing mouse and human cell lines were generated and functionally characterized. By fusion with replication-supporting but non-infectable HepG2 cells, we analysed the ability of these heterokaryonic cells to fully support HBV replication by HBcAg expression and HBsAg/HBeAg secretion.

Results: While hNTCP expression in three mouse cell lines and the non-hepatic human HeLa cells conferred susceptibility to HDV, HBV replication was still restricted. Upon fusion of refractive cells to HepG2 cells, all heterokaryonic cells supported receptor-mediated infection with HBV. hNTCP was provided by the mouse cells and replication competence came from the HepG2 cell line. Transfection of a covalently closed circular DNA (cccDNA)-like molecule into non-susceptible cells promoted gene expression, indicating that the limiting step is upstream of cccDNA formation.

Conclusions: In addition to the expression of hNTCP, establishment of HBV infection in mouse and non-hepatocytic human cell lines requires supplementation with a dependency factor and is not limited by a restriction factor. This result opens new avenues for the development of a fully permissive immunocompetent HBV mouse model.

Keywords: Cell fusion; HBV; HDV; Hepatitis B virus; Hepatitis D virus; Mouse model; NTCP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Hep G2 Cells
  • Hepatitis B virus / physiology*
  • Hepatitis Delta Virus / physiology
  • Hepatocytes / virology
  • Humans
  • Mice
  • Organic Anion Transporters, Sodium-Dependent / genetics
  • Organic Anion Transporters, Sodium-Dependent / physiology*
  • Symporters / genetics
  • Symporters / physiology*
  • Virus Replication*


  • Organic Anion Transporters, Sodium-Dependent
  • Symporters
  • sodium-bile acid cotransporter