Hepatitis C virus Broadly Neutralizing Monoclonal Antibodies Isolated 25 Years after Spontaneous Clearance

PLoS One. 2016 Oct 24;11(10):e0165047. doi: 10.1371/journal.pone.0165047. eCollection 2016.

Abstract

Hepatitis C virus (HCV) is world-wide a major cause of liver related morbidity and mortality. No vaccine is available to prevent HCV infection. To design an effective vaccine, understanding immunity against HCV is necessary. The memory B cell repertoire was characterized from an intravenous drug user who spontaneously cleared HCV infection 25 years ago. CD27+IgG+ memory B cells were immortalized using BCL6 and Bcl-xL. These immortalized B cells were used to study antibody-mediated immunity against the HCV E1E2 glycoproteins. Five E1E2 broadly reactive antibodies were isolated: 3 antibodies showed potent neutralization of genotype 1 to 4 using HCV pseudotyped particles, whereas the other 2 antibodies neutralized genotype 1, 2 and 3 or 1 and 2 only. All antibodies recognized non-linear epitopes on E2. Finally, except for antibody AT12-011, which recognized an epitope consisting of antigenic domain C /AR2 and AR5, all other four antibodies recognized epitope II and domain B. These data show that a subject, who spontaneously cleared HCV infection 25 years ago, still has circulating memory B cells that are able to secrete broadly neutralizing antibodies. Presence of such memory B cells strengthens the argument for undertaking the development of an HCV vaccine.

MeSH terms

  • Adult
  • Antibodies, Monoclonal / isolation & purification*
  • Antibodies, Neutralizing / isolation & purification*
  • B-Lymphocytes / cytology
  • B-Lymphocytes / immunology
  • Epitopes / immunology
  • Genotype
  • Hepacivirus / genetics
  • Hepacivirus / immunology*
  • Hepacivirus / metabolism
  • Hepatitis C / blood*
  • Hepatitis C / therapy
  • Hepatitis C Antibodies / isolation & purification*
  • Humans
  • Male
  • Substance Abuse, Intravenous / virology
  • Viral Envelope Proteins / immunology*
  • Viral Hepatitis Vaccines / immunology

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Epitopes
  • Hepatitis C Antibodies
  • Viral Envelope Proteins
  • Viral Hepatitis Vaccines

Grants and funding

This study was supported by the Virgo consortium, funded by the Dutch government project number FES0908 (http://virgo.nl/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.