Characterization and epitope mapping of monoclonal antibodies raised against rat hepatitis E virus capsid protein: An evaluation of their neutralizing activity in a cell culture system

J Virol Methods. 2016 Jul:233:78-88. doi: 10.1016/j.jviromet.2016.03.004. Epub 2016 Mar 16.

Abstract

Hepatitis E virus (HEV) is the causative agent of acute hepatitis. Rat HEV is a recently discovered virus related to, but distinct from, human HEV. Since laboratory rats can be reproducibly infected with rat HEV and a cell culture system has been established for rat HEV, this virus may be used as a surrogate virus for human HEV, enabling studies on virus replication and mechanism of infection. However, monoclonal antibodies (MAbs) against rat HEV capsid (ORF2) protein are not available. In this study, 12 murine MAbs were generated against a recombinant ORF2 protein of rat HEV (rRatHEV-ORF2: amino acids 101-644) and were classified into at least six distinct groups by epitope mapping and a cross-reactivity analysis with human HEV ORF2 proteins. Two non-cross-reactive MAbs recognizing the protruding (P) domain detected both non-denatured and denatured rRatHEV-ORF2 protein and efficiently captured cell culture-produced rat HEV particles that had been treated with deoxycholate and trypsin, but not those without prior treatment. In addition, these two MAbs were able to efficiently neutralize replication of cell culture-generated rat HEV particles without lipid membranes (but not those with lipid membranes) in a cell culture system, similar to human HEV.

Keywords: Capsid protein; Epitope mapping; Monoclonal antibodies; Neutralization; Rat hepatitis E virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / immunology*
  • Antibody Specificity / immunology
  • Antigens, Viral / immunology
  • Blotting, Western
  • Capsid Proteins / genetics
  • Capsid Proteins / immunology*
  • Cell Culture Techniques
  • Cross Reactions / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Epitope Mapping*
  • Epitopes / metabolism
  • Fluorescent Antibody Technique, Indirect
  • Hepatitis E virus / genetics
  • Hepatitis E virus / immunology*
  • Humans
  • Neutralization Tests
  • Polymerase Chain Reaction
  • RNA, Viral
  • Rats
  • Recombinant Proteins / immunology
  • Viral Proteins / genetics
  • Viral Proteins / immunology

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Antigens, Viral
  • Capsid Proteins
  • Epitopes
  • ORF2 protein, Hepatitis E virus
  • RNA, Viral
  • Recombinant Proteins
  • Viral Proteins