Heterologous T cells can help restore function in dysfunctional hepatitis C virus nonstructural 3/4A-specific T cells during therapeutic vaccination

J Immunol. 2011 May 1;186(9):5107-18. doi: 10.4049/jimmunol.1001790. Epub 2011 Mar 23.

Abstract

The hepatitis C virus (HCV)-specific T cell response in patients with chronic HCV is dysfunctional. In this study, we aimed at restoring immunological function through therapeutic vaccination in a transgenic mouse model with impaired HCV-specific T cell responses due to a persistent presence of hepatic HCV nonstructural (NS)3/4A Ags. The HCV-specific T cells have an actively maintained dysfunction reflected in reduced frequency, impaired cytokine production, and impaired effector function in vivo, which can be partially restored by blocking regulatory T cells or programmed cell death ligand 1. We hypothesized that the impairment could be corrected by including sequences that created a normal priming environment by recruiting "healthy" heterologous T cells and by activating innate signaling. Endogenously expressed hepatitis B core Ag (HBcAg) can recruit heterologous T cells and activate TLR (TLR7) signaling. Hence, by combining HCV NS3/4A with different forms of HBcAg we found that heterologous sequences somewhat improved activation and expansion of NS3/4A-specific T cells in a wild-type host. Importantly, the signals provided by HBcAg effectively restored the activation of HCV-specific T cells in a tolerant NS3/4A-transgenic mouse model. The adjuvant effect could also be transferred to the priming of dysfunctional HLA-A2-restricted NS3-specific T cells in vivo. Thus, recruiting healthy heterologous T cells to the site of priming may also help restore HCV-specific responses present in a chronically infected host.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Antigens, Viral / immunology
  • Antigens, Viral / therapeutic use
  • Blotting, Western
  • Cell Line, Tumor
  • Disease Models, Animal
  • Enzyme-Linked Immunosorbent Assay
  • Hepacivirus / immunology
  • Hepatitis B Core Antigens / immunology
  • Hepatitis B Core Antigens / therapeutic use
  • Hepatitis C, Chronic / immunology*
  • Hepatitis C, Chronic / therapy
  • Humans
  • Immunoprecipitation
  • Lymphocyte Activation / immunology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • T-Lymphocytes / immunology*
  • Vaccination / methods*
  • Viral Hepatitis Vaccines / immunology*
  • Viral Nonstructural Proteins / immunology*

Substances

  • Antigens, Viral
  • Hepatitis B Core Antigens
  • NS3 protein, hepatitis C virus
  • NS4 protein, hepatitis C virus
  • Viral Hepatitis Vaccines
  • Viral Nonstructural Proteins