A human monoclonal antibody against HPV16 recognizes an immunodominant and neutralizing epitope partially overlapping with that of H16.V5

Sci Rep. 2016 Jan 11:6:19042. doi: 10.1038/srep19042.

Abstract

The presence of neutralizing epitopes in human papillomavirus (HPV) L1 virus-like particles (VLPs) is the structural basis of prophylactic vaccines. An anti-HPV16 neutralizing monoclonal antibody (N-mAb) 26D1 was isolated from a memory B cell of a human vaccinee. The pre-binding of heparan sulfate to VLPs inhibited the binding of both N-mAbs to the antigen, indicating that the epitopes are critical for viral cell attachment/entry. Hybrid VLP binding with surface loop swapping between types indicated the essential roles of the DE and FG loops for both 26D1 (DEa in particular) and H16.V5 binding. Specifically, Tyr(135) and Val(141) on the DEa loop were shown to be critical residues for 26D1 binding via site-directed mutagenesis. Partially overlap between the epitopes between 26D1 and H16.V5 was shown using pairwise epitope mapping, and their binding difference is demonstrated to be predominantly in DE loop region. In addition, 26D1 epitope is immunodominant epitope recognized by both antibodies elicited by the authentic virus from infected individuals and polyclonal antibodies from vaccinees. Overall, a partially overlapping but distinct neutralizing epitope from that of H16.V5 was identified using a human N-mAb, shedding lights to the antibody arrays as part of human immune response to vaccination and infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / biosynthesis
  • Antibodies, Monoclonal / chemistry*
  • Antibodies, Neutralizing / biosynthesis
  • Antibodies, Neutralizing / chemistry*
  • Antibody Affinity
  • Antibody Specificity
  • B-Lymphocytes / chemistry
  • B-Lymphocytes / immunology
  • B-Lymphocytes / virology
  • Capsid Proteins / chemistry
  • Capsid Proteins / immunology*
  • Epitope Mapping
  • Epitopes / chemistry
  • Epitopes / immunology
  • Female
  • Heparitin Sulfate / chemistry
  • Heparitin Sulfate / pharmacology
  • Human papillomavirus 16 / chemistry
  • Human papillomavirus 16 / immunology*
  • Humans
  • Immune Sera / chemistry
  • Immunologic Memory
  • Molecular Docking Simulation
  • Mutation
  • Neutralization Tests
  • Papillomavirus Vaccines / administration & dosage
  • Papillomavirus Vaccines / chemistry*
  • Papillomavirus Vaccines / immunology
  • Protein Binding / drug effects
  • Protein Domains
  • Vaccination
  • Vaccines, Virus-Like Particle / administration & dosage
  • Vaccines, Virus-Like Particle / chemistry*
  • Vaccines, Virus-Like Particle / immunology

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Capsid Proteins
  • Epitopes
  • Immune Sera
  • Papillomavirus Vaccines
  • Vaccines, Virus-Like Particle
  • Heparitin Sulfate