Modeling host interactions with hepatitis B virus using primary and induced pluripotent stem cell-derived hepatocellular systems

Abstract

Hepatitis B virus (HBV) chronically infects 400 million people worldwide and is a leading driver of end-stage liver disease and liver cancer. Research into the biology and treatment of HBV requires an in vitro cell-culture system that supports the infection of human hepatocytes, and accurately recapitulates virus-host interactions. Here, we report that micropatterned cocultures of primary human hepatocytes with stromal cells (MPCCs) reliably support productive HBV infection, and infection can be enhanced by blocking elements of the hepatocyte innate immune response associated with the induction of IFN-stimulated genes. MPCCs maintain prolonged, productive infection and represent a facile platform for studying virus-host interactions and for developing antiviral interventions. Hepatocytes obtained from different human donors vary dramatically in their permissiveness to HBV infection, suggesting that factors-such as divergence in genetic susceptibility to infection-may influence infection in vitro. To establish a complementary, renewable system on an isogenic background in which candidate genetics can be interrogated, we show that inducible pluripotent stem cells differentiated into hepatocyte-like cells (iHeps) support HBV infection that can also be enhanced by blocking interferon-stimulated gene induction. Notably, the emergence of the capacity to support HBV transcriptional activity and initial permissiveness for infection are marked by distinct stages of iHep differentiation, suggesting that infection of iHeps can be used both to study HBV, and conversely to assess the degree of iHep differentiation. Our work demonstrates the utility of these infectious systems for studying HBV biology and the virus' interactions with host hepatocyte genetics and physiology.HBV persistence | innate immunity | viral hepatitis H epatitis B virus (HBV) is a small 3.2-kb DNA virus that selectively infects hepatocytes in the human liver (1). The global disease burden is large, with ∼400 million people chronically infected worldwide, of whom about one-third will develop severe HBV-related complications, such as cirrhosis and liver cancer. Lifelong treatment is often required because of the stable nature of viral episomal DNA, known as covalently closed circular DNA (cccDNA), which maintains basal levels in infected cell nuclei even upon nucleos(t)ide inhibitor treatment. To date, HBV research has been hampered by a distinct lack of robust infectious model systems that both support productive HBV infection and accurately mimic virus-host interactions. Recently, the bile acid pump sodium taurocholate cotransporting polypeptide (NTCP) has been identified as a receptor for both HBV and hepatitis D virus (2), and overexpression of NTCP in hepatoma cell lines renders them susceptible to HBV infection. However, hepatoma cells are known to be defective in many cellular pathways implicated in the innate immune response (3, 4), metabolism (5), and cell proliferation (6), which may contribute to published contradictory evidence regarding the e...

Contribution of Toll-like receptors to the control of hepatitis B virus infection by initiating antiviral innate responses and promoting specific adaptive immune responses

“…The development of new in vitro methods of HBV infection will soon shed some light on the recognition of HBV by PRRs. [98][99][100] Previous studies indicated that HBV infection apparently does not activate innate immunity in chimpanzees and patients. HBV proteins, such as HBsAg, HBx and HBV polymerase, are associated with the inhibition of TLR or RLR signaling pathways and lead to impaired IFN production.…”

Hepatitis B Virus and DNA Stimulation Trigger a Rapid Innate Immune Response through NF-κB

“…Using experimentally infected chimpanzees, microarray analyses suggested that HBV, early in infection, does not modulate host cellular gene transcription significantly and would induce neither innate antiviral responses in hepatocytes nor intrahepatic innate immune responses (7). After this study, HBV was designated as a "stealth virus" (8), but this may not be the case (9). Furthermore, a study demonstrated that HBV may be cleared from infected hepatocytes before any detectable adaptive immune response (10), thus suggesting that innate immunity or antiviral responses at the level of infected cells could play an important role.…”

Cell sources forin vitrohuman liver cell culture models

“…146,147 Studies on MPCC with hiPSC-derived human hepatocytes 148 indicate a similar sensitivity toward drug toxicity as observed in MPCC using PHH. 51 In addition, hepatocytes generated from pluripotent stem cells have been successfully applied in in vitro studies on infectious diseases like hepatitis B and C infection 149,150 or malaria pathogenesis. 151 Moreover, inherited metabolic liver diseases can be modeled by reprogramming cells from those patients and differentiating hiPSC into the affected cell type, as shown for a1-antitrypsin deficiency, familial hypercholesterolemia, and glycogen storage disease type 1a.…”