T-cell immunity and hepatitis C virus reinfection after cure of chronic hepatitis C with an interferon-free antiviral regimen in a chimpanzee

Hepatology. 2014 Nov;60(5):1531-40. doi: 10.1002/hep.27278. Epub 2014 Sep 25.


Memory CD8+ T cells generated by spontaneous resolution of hepatitis C virus (HCV) infection rapidly control secondary infections and reduce the risk of virus persistence. Here, CD8+ T-cell immunity and response to reinfection were assessed in a chimpanzee cured of an earlier chronic infection with an interferon (IFN)-free antiviral regimen. CD8+ T cells expanded from liver immediately before and 2 years after cure of chronic infection with two direct-acting antivirals (DAAs) targeted epitopes in the E2, nonstructural (NS)5a, and NS5b proteins. A second infection to assess CD8+ T-cell responsiveness resulted in rapid suppression of HCV replication by week 2, but viremia rebounded 3 weeks later and the infection persisted. The E2, NS5a, and NS5b proteins remained dominant CD8+ T-cell targets after reinfection. Resurgent HCV replication was temporally associated with mutational escape of NS5a and NS5b class I epitopes that had also mutated during the first chronic infection. Two epitopes in E2 remained intact throughout both persistent infections. Intrahepatic CD8+ T cells targeting intact and escape-prone epitopes differed in expression of phenotypic markers of functional exhaustion 2 years after successful DAA therapy and in the capacity to expand in liver upon reinfection.

Conclusions: The intrahepatic HCV-specific CD8+ T-cell repertoire established during chronic infection was narrowly focused, but very stable, after cure with DAA. Existing intrahepatic CD8+ T cells targeting dominant epitopes of the challenge virus failed to prevent persistence. Vaccination after DAA cure may be necessary to broaden T-cell responses and reduce the risk of a second persistent infection.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiviral Agents / pharmacology
  • Antiviral Agents / therapeutic use
  • CD8-Positive T-Lymphocytes / immunology*
  • Hepacivirus / immunology*
  • Hepatitis, Viral, Animal / drug therapy
  • Hepatitis, Viral, Animal / immunology*
  • Hepatitis, Viral, Animal / virology
  • Pan troglodytes
  • Recurrence
  • Viral Nonstructural Proteins / antagonists & inhibitors*
  • Viral Nonstructural Proteins / immunology


  • Antiviral Agents
  • Viral Nonstructural Proteins
  • NS-5 protein, hepatitis C virus