Recombinant Flag-tagged E1E2 glycoproteins from three hepatitis C virus genotypes are biologically functional and elicit cross-reactive neutralizing antibodies in mice

Virology. 2018 Jun:519:33-41. doi: 10.1016/j.virol.2018.03.026. Epub 2018 Apr 6.

Abstract

Hepatitis C virus (HCV) is a globally disseminated human pathogen for which no vaccine is currently available. HCV is highly diverse genetically and can be classified into 7 genotypes and multiple sub-types. Due to this antigenic variation, the induction of cross-reactive and at the same time neutralizing antibodies is a challenge in vaccine production. Here we report the analysis of immunogenicity of recombinant HCV envelope glycoproteins from genotypes 1a, 1b and 2a, with a Flag tag inserted in the hypervariable region 1 of E2. This modification did not affect protein expression or conformation or its capacity to bind the crucial virus entry factor, CD81. Importantly, in immunogenicity studies on mice, the purified E2-Flag mutants elicited high-titer, cross-reactive antibodies that were able to neutralize HCV infectious particles from two genotypes tested (1a and 2a). These findings indicate that E1E2-Flag envelope glycoproteins could be important immunogen candidates for vaccine aiming to induce broad HCV-neutralizing responses.

Keywords: E1E2; Envelope glycoproteins; Flag tag; Hepatitis C virus; Neutralization; Vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / biosynthesis
  • Antibodies, Neutralizing / immunology*
  • Antibodies, Viral / immunology*
  • Cell Line
  • Cross Reactions
  • Epitope Mapping
  • Epitopes / immunology
  • Genotype
  • Hepacivirus / genetics
  • Hepacivirus / immunology*
  • Hepacivirus / physiology
  • Humans
  • Immunogenicity, Vaccine
  • Mice
  • Neutralization Tests
  • Receptors, Virus / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology
  • Tetraspanin 28 / metabolism
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / immunology*
  • Viral Envelope Proteins / metabolism
  • Virus Internalization

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • E1 protein, Hepatitis C virus
  • Epitopes
  • Receptors, Virus
  • Recombinant Proteins
  • Tetraspanin 28
  • Viral Envelope Proteins
  • glycoprotein E2, Hepatitis C virus