Table 1. Summary of HBV in vitro hepatocyte culture models
From: Advances in HBV infection and replication systems in vitro
Classification | Cell line | Advantages | Shortcomings | HBV infection rate and application of the models |
|---|---|---|---|---|
HBV replication cell lines | (1) HepG2.2.15 cells | cccDNA accumulation Stable and continuous HBV gene expression and replication | Low viral replication level Antigen expression instability Virions are produced from the integrated DNA | Screening and evaluation of antiviral drugs, etc. [90]. |
| Â | (2) HepAD38 (EF9,EFS19) cells | Cells differentiate quickly Produce high titers of viral particles cccDNA accumulation Hepatoma cells stably expressing HBV from a Tet-on/Tet-off system | Incomplete viral life cycle Virions are produced from the integrated DNA | Screening and evaluation of antiviral drugs, etc. A potential source for tissue culture derived virions [91]. |
| Â | (3) Ad-HBV1.3-systems | No species barrier Efficient expression of HBV HBV expression and mutation can be controlled Direct observation of transfection and infection efficiency (integrated green fluorescent protein gene) | Missing HBV natural infection stage | Used to establish animal models of acute hepatitis B infection [92]. |
| Â | (4) HBV baculovirus system | Easy detection of riboprotein-bound HBV DNA High HBV replication level Formation of infectious viruses and a detectable intracellular cccDNA pool | Nonreceptor-mediated entry Gene transfer is restricted to certain species Missing HBV natural infection stage | Quantify the effect of antiviral agents on nuclear HBV DNA Used for studying the resistance of HBV to nucleoside analogs [93]. |
Cell lines that can be infected with HBV | (1) Human fetal hepatocytes | Phenotypically and biologically functionally close to primary adult human hepatocytes | Low infection efficiency Short infection time Limited availability Large donor-donor variations | HBV infection rate12%-90% [22, 94]. Coculturing with hepatic non-parenchymal cells and subsequent addition of 2% DMSO leads to the formation of hepatocyte islands with prolonged phenotypic maintenance [25]. The early events in viral entry into cells as well as viral replication [23]. |
| Â | (2) Adult human hepatocytes | The gold standard host cell to HBV infection experiments Closest to the physiological characteristics of hepatocytes in vivo Close to the natural process of infection | Limited life cycle Unpassable culture Phenotypically unstable in vitro Rapidly lose permissiveness for HBV infection Large donor-donor variations | HBV infection rate 20%-100% [26, 28]. Used for studying the process of HBV infection [5, 28]. Studying on apoptosis [26]. Preparation of 3D primary hepatocyte culture system for analyses of liver diseases, drug metabolism, and toxicity [40, 41]. |
| Â | (3) Co-culture system | Test the utility of various direct-acting antivirals (DAAs) and putative host-targeting antivirals (HTAs); Assessing preclinically the efficacy of other entry inhibitors and possibly (vaccine-induced) neutralizing antibodies; | Wide variability between donors in terms of HBV permissiveness | Inflammation and drug-Induced Hepatotoxicity [95]. |
| Â | (4) Primary Tupaia hepatocytes | The only species susceptible for HBV infection besides humans and chimpanzees | Expensive | HBV infection rate >70% [52]. Used for in vitro as well asin vivo infection experiments [96]. HBV specific receptor identification [78]. |
| Â | (5) HepaRG cells | Preserve the specific functional properties of hepatocytes Support the complete HBV life cycle Produce HBV cccDNA | Strict culture conditions Low infection efficiency | HBV infection rate <30% [56, 78]. HBV molecular mechanism and screening, evaluation of anti-HBV drugs; cccDNA spread etc. [57]. |
| Â | (6) In vitro systems based on induced pluripotent stem (iPS) cell-derived human hepatocytes | Biological characteristics similar to those of normal liver cells Support the complete life cycle of the virus Complete natural immune system | Complicated operation | HBV infection rate 25% [97]. Drug hepatotoxicity screening [98]. The life cycle of HBV virus and virus-induced hepatic dysfunction [66]. |
| Â | (7) NTCP overexpressing hepatoma cell lines | Support the complete life cycle of the virus Flexibility and easy handling | Low susceptibility to serum-derived HBV The multiplicity of infection (MOI) needed to achieve infection is extremely high No substantial viral spreading following infection | HBV infection rate 50% [99]. Large-scale screening of antiviral drugs for targeting NTCP [91]. |