Comprehensive mapping of antigen specific T cell responses in hepatitis C virus infected patients with or without spontaneous viral clearance

PLoS One. 2017 Feb 7;12(2):e0171217. doi: 10.1371/journal.pone.0171217. eCollection 2017.

Abstract

Elucidating protective immunity against HCV is important for the development of a preventative vaccine. We hypothesize that spontaneous resolution of acute HCV infection offers clue to protective immune responses, and that DAA therapy affects the quality and quantity of HCV-specific T cell responses. To test these hypotheses, we performed T cell epitope mapping in 111 HCV-infected individuals including 61 chronically HCV-1b (CHC-1b) infected, 24 chronically HCV-2a (CHC-2a) infected and 26 spontaneously recovered (SPR) patients with 376 overlapping peptides covering the entire HCV polyprotein. Selected T cell epitopes were then used to evaluate T cell responses in another 22 chronically HCV-1b infected patients on DAA therapy. Results showed that SPR had better HCV-specific T cell responses than CHC, as manifested by higher response rate, greater magnitude and broader epitope coverage. In addition, SPR recognized novel epitopes in Core, E1, E2, NS4B, NS5A regions that were not present in the CHC. Furthermore, during the first 24 weeks of DAA therapy, there was no functional immune reconstitution of HCV-specific T cells. These results indicate that T cell responses may be a correlate of protection. Therefore, effective preventative vaccines should elicit a robust T cell response. Although various DAA regimens efficiently cleared viruses from the blood of HCV-infected patients, there was no contemporaneous early T cell immune reconstitution, suggesting that early treatment is needed for preserving the functions of HCV-specific T cells.

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal / pharmacology
  • Antiviral Agents / therapeutic use
  • Cytokines / metabolism
  • Epitope Mapping*
  • Epitopes, T-Lymphocyte / genetics
  • Epitopes, T-Lymphocyte / immunology*
  • Female
  • Genotype
  • Hepacivirus / genetics
  • Hepacivirus / immunology*
  • Hepatitis C / drug therapy
  • Hepatitis C / immunology*
  • Hepatitis C / virology*
  • Humans
  • Lymphocyte Activation
  • Male
  • Middle Aged
  • Patient Outcome Assessment
  • Peptides / genetics
  • Peptides / immunology
  • Phylogeny
  • Programmed Cell Death 1 Receptor / antagonists & inhibitors
  • T-Lymphocyte Subsets / drug effects
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • Viral Load*
  • Young Adult

Substances

  • Antibodies, Monoclonal
  • Antiviral Agents
  • Cytokines
  • Epitopes, T-Lymphocyte
  • Peptides
  • Programmed Cell Death 1 Receptor

Grants and funding

This study was supported by grants from the Chinese Ministry of Science and Technology 973 Grant (#2015CB554304), National Science and Technology Major Project (#2012ZX10002007) and Natural Science Foundation of China (#81373143, #81571535) of the First Hospital of Jilin University, the Capital Characteristic Clinical Application Research (#Z161100000516018) and the Capital Health and Development Research Fund (#2016-1-2183) of the Beijing You'an Hospital of Capital Medical University. The funders have been involved in the study design, data collection and analysis, decision to publish, and preparation of the manuscript.