Characterization of hepatitis B virus (HBV)-specific T-cell dysfunction in chronic HBV infection

J Virol. 2007 Apr;81(8):4215-25. doi: 10.1128/JVI.02844-06. Epub 2007 Feb 7.

Abstract

Dysfunctional CD8+ T cells present in chronic virus infections can express programmed death 1 (PD-1) molecules, and the inhibition of the engagement of PD-1 with its ligand (PD-L1) has been reported to enhance the antiviral function of these T cells. We took advantage of the wide fluctuations in levels of viremia which are typical of chronic hepatitis B virus (HBV) infection to comprehensively analyze the impact of prolonged exposure to different virus quantities on virus-specific T-cell dysfunction and on its reversibility through the blocking of the PD-1/PD-L1 pathway. We confirm that chronic HBV infection has a profound effect on the HBV-specific T-cell repertoire. Despite the use of a comprehensive panel of peptides covering all HBV proteins, HBV-specific T cells were rarely observed directly ex vivo in samples from patients with chronic infection, in contrast to those from patients with acute HBV infection. In chronic HBV infection, virus-specific T cells were detected mainly in patients with lower levels of viremia. These HBV-specific CD8+ T cells expressed PD-1, and their function was improved by the blocking of PD-1/PD-L1 engagement. Thus, a broad spectrum of anti-HBV immunity is expressed by patients with chronic HBV infection and this spectrum is proportional to HBV replication levels and can be improved by blocking the PD-1/PD-L1 pathway. This information may be useful for the design of immunotherapeutic strategies to complement and optimize available antiviral therapies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / analysis
  • Antigens, CD / immunology
  • Apoptosis Regulatory Proteins / analysis
  • Apoptosis Regulatory Proteins / antagonists & inhibitors
  • B7-H1 Antigen
  • CD8-Positive T-Lymphocytes / immunology*
  • Cells, Cultured
  • Hepatitis B / immunology
  • Hepatitis B / virology
  • Hepatitis B virus / immunology*
  • Hepatitis B, Chronic / immunology*
  • Hepatitis B, Chronic / virology
  • Humans
  • Immune Tolerance
  • Leukocytes, Mononuclear
  • Longitudinal Studies
  • Programmed Cell Death 1 Receptor
  • T-Lymphocyte Subsets / immunology
  • Viremia

Substances

  • Antigens, CD
  • Apoptosis Regulatory Proteins
  • B7-H1 Antigen
  • CD274 protein, human
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor