BioProject

The woodchuck model of hepatitis B virus (HBV) infection displays many characteristics of human infection and has particular value for characterizing the host immune responses during the development of chronic infection. More...

The woodchuck model of hepatitis B virus (HBV) infection displays many characteristics of human infection and has particular value for characterizing the host immune responses during the development of chronic infection. Using the newly developed custom woodchuck microarray platform, we compared the intrahepatic transcriptional responses of neonatal woodchucks with self-limiting and progressing persistent infection with woodchuck hepatitis virus (WHV). This revealed that WHV does not induce intrahepatic gene expression during the early acute stage of infection (8 weeks), suggesting it is a “stealth” virus. At the mid-acute phase of infection (14 weeks), resolution was associated with induction of a prominent cytotoxic T cell signature, with perforin and other markers of immune-mediated cytotolytic response being strongly expressed. Strikingly, this was accompanied by high level expression of PD-1 and various other inhibitory T cell receptors, which likely act to minimize liver damage by cytotoxic T cells during viral clearance. Conversely, self-limiting infection was not associated with a strong interferon-α/β (IFN-α/β) transcriptional response, while the IFN-γ signaling response (as measured by expression of CXCL9) in the mid-acute phase was comparable to that in chronically infected adult animals. Nevertheless, viperin and other antiviral genes were differentially expressed during resolving infection, suggesting that a subset of interferon-stimulated genes (ISGs) may play a role in the control of WHV replication. Conclusion: This study identifies new immune pathways associated with the clearance of hepadnavirus infection and reveals novel targets with potential for the treatment of chronic hepatitis B. Overall design: Neonatal woodchucks of both genders were infected at 3 days of age with the same WHV7P1 inoculum containing 5 x 106 WID50 of WHV strain WHV7-11. Custom microarrays were generated from sequences obtained in transcriptome sequencing of woodchuck liver and PBMCs, and were used to examine liver gene expression in animals which eventually become chronically infected with WHV (8 weeks, n=5; 14 weeks, n=9), animals that eventually resolve WHV infection (8 weeks, n=10;14 weeks, n=7) and uninfected animals (8 weeks, n=5;14 weeks,n=5). Less...