Outcome of Antiviral Immunity in the Liver Is Shaped by the Level of Antigen Expressed in Infected Hepatocytes

Hepatology. 2018 Dec;68(6):2089-2105. doi: 10.1002/hep.30080. Epub 2018 Sep 27.


The liver bears unique immune properties that support both immune tolerance and immunity, but the mechanisms responsible for clearance versus persistence of virus-infected hepatocytes remain unclear. Here, we dissect the factors determining the outcome of antiviral immunity using recombinant adenoviruses that reflect the hepatropism and hepatrophism of hepatitis viruses. We generated replication-deficient adenoviruses with equimolar expression of ovalbumin, luciferase, and green fluorescent protein driven by a strong ubiquitous cytomegalovirus (CMV) promoter (Ad-CMV-GOL) or by 100-fold weaker, yet hepatocyte-specific, transthyretin (TTR) promoter (Ad-TTR-GOL). Using in vivo bioluminescence to quantitatively and dynamically image luciferase activity, we demonstrated that Ad-TTR-GOL infection always persists, whereas Ad-CMV-GOL infection is always cleared, independent of the number of infected hepatocytes. Failure to clear Ad-TTR-GOL infection involved mechanisms acting during initiation as well as execution of antigen-specific immunity. First, hepatocyte-restricted antigen expression led to delayed and curtailed T-cell expansion-10,000-fold after Ad-CMV-GOL versus 150-fold after Ad-TTR-GOL-infection. Second, CD8 T-cells primed toward antigens selectively expressed by hepatocytes showed high PD-1/Tim-3/LAG-3/CTLA-4/CD160 expression levels similar to that seen in chronic hepatitis B. Third, Ad-TTR-GOL but not Ad-CMV-GOL-infected hepatocytes escaped being killed by effector T-cells while still inducing high PD-1/Tim-3/LAG-3/CTLA-4/CD160 expression, indicating different thresholds of T-cell receptor signaling relevant for triggering effector functions compared with exhaustion. Conclusion: Our study identifies deficits in the generation of CD8 T-cell immunity toward hepatocyte-expressed antigens and escape of infected hepatocytes expressing low viral antigen levels from effector T-cell killing as independent factors promoting viral persistence. This highlights the importance of addressing both the restauration of CD8 T-cell dysfunction and overcoming local hurdles of effector T-cell function to eliminate virus-infected hepatocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae
  • Animals
  • Antigens / metabolism
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytomegalovirus / genetics
  • Gene Expression
  • Hepatitis, Viral, Animal / immunology*
  • Hepatocytes / immunology*
  • Lymphocyte Activation
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Prealbumin / genetics
  • Promoter Regions, Genetic


  • Antigens
  • Prealbumin