High, broad, polyfunctional, and durable T cell immune responses induced in mice by a novel hepatitis C virus (HCV) vaccine candidate (MVA-HCV) based on modified vaccinia virus Ankara expressing the nearly full-length HCV genome

J Virol. 2013 Jul;87(13):7282-300. doi: 10.1128/JVI.03246-12. Epub 2013 Apr 17.

Abstract

A major goal in the control of hepatitis C infection is the development of a vaccine. Here, we have developed a novel HCV vaccine candidate based on the highly attenuated poxvirus vector MVA (referred to as MVA-HCV) expressing the nearly full-length (7.9-kbp) HCV sequence, with the aim to target almost all of the T and B cell determinants described for HCV. In infected cells, MVA-HCV produces a polyprotein that is subsequently processed into the structural and nonstructural HCV proteins, triggering the cytoplasmic accumulation of dense membrane aggregates. In both C57BL/6 and transgenic HLA-A2-vaccinated mice, MVA-HCV induced high, broad, polyfunctional, and long-lasting HCV-specific T cell immune responses. The vaccine-induced T cell response was mainly mediated by CD8 T cells; however, although lower in magnitude, the CD4(+) T cells were highly polyfunctional. In homologous protocol (MVA-HCV/MVA-HCV) the main CD8(+) T cell target was p7+NS2, whereas in heterologous combination (DNA-HCV/MVA-HCV) the main target was NS3. Antigenic responses were also detected against other HCV proteins (Core, E1-E2, and NS4), but the magnitude of the responses was dependent on the protocol used. The majority of the HCV-induced CD8(+) T cells were triple or quadruple cytokine producers. The MVA-HCV vaccine induced memory CD8(+) T cell responses with an effector memory phenotype. Overall, our data showed that MVA-HCV induced broad, highly polyfunctional, and durable T cell responses of a magnitude and quality that might be associated with protective immunity and open the path for future considerations of MVA-HCV as a prophylactic and/or therapeutic vaccine candidate against HCV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Viral / immunology*
  • Blotting, Western
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Line
  • Cricetinae
  • Cytokines / metabolism
  • Genetic Vectors
  • HLA-A2 Antigen / immunology
  • HeLa Cells
  • Hepacivirus / genetics*
  • Hepacivirus / immunology*
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Microscopy, Electron
  • Microscopy, Fluorescence
  • Oligonucleotides / genetics
  • Phosphorylation
  • Polymerase Chain Reaction
  • Real-Time Polymerase Chain Reaction
  • Vaccines, DNA
  • Viral Hepatitis Vaccines / genetics
  • Viral Hepatitis Vaccines / immunology*
  • Viral Vaccines / genetics
  • Viral Vaccines / immunology

Substances

  • Antigens, Viral
  • Cytokines
  • HLA-A2 Antigen
  • MVA vaccine
  • Oligonucleotides
  • Vaccines, DNA
  • Viral Hepatitis Vaccines
  • Viral Vaccines