Misdirected antibody responses against an N-terminal epitope on human rhinovirus VP1 as explanation for recurrent RV infections

FASEB J. 2012 Mar;26(3):1001-8. doi: 10.1096/fj.11-193557. Epub 2011 Nov 25.

Abstract

Rhinoviruses (RVs) are the primary cause of upper respiratory tract infections, generally known as the common cold. Moreover, RV infections can trigger severe exacerbations of asthma and chronic obstructive pulmonary disease (COPD). We expressed the 4 major RV capsid proteins, VP1-VP4, in Escherichia coli and used these proteins as well as recombinant and synthetic VP1 fragments to study and map antibody responses in RV-infected humans. VP1, which on infection binds to ICAM 1, was identified as a major target for the memory immune response, residing in the IgG1 subclass and IgA class. Interestingly, this response was mainly directed against an N-terminal 20 mer peptide in VP1, P1a, which becomes exposed on intact RV only when it docks to its receptor ICAM 1. Molecular modeling using the 3-dimensional RV capsid structures revealed that P1a was localized inside the capsid and outside the areas involved in receptor binding or RV neutralization. Our results suggest misdirection of antibody responses against a nonprotective epitope as a mechanism how RV escapes immunity and causes recurrent infections. Based on these findings, it may be possible to design vaccines against RV infections and RV-induced respiratory diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Viral / immunology*
  • Capsid / immunology
  • Capsid / metabolism
  • Child
  • Common Cold / immunology*
  • Common Cold / virology
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes / genetics
  • Epitopes / immunology*
  • Host-Pathogen Interactions / immunology
  • Humans
  • Immunoglobulin A / immunology
  • Immunoglobulin G / immunology
  • Intercellular Adhesion Molecule-1 / immunology
  • Intercellular Adhesion Molecule-1 / metabolism
  • Molecular Sequence Data
  • Recombinant Proteins / immunology
  • Rhinovirus / genetics
  • Rhinovirus / immunology*
  • Rhinovirus / physiology
  • Seasons
  • Sequence Homology, Amino Acid
  • Viral Proteins / genetics
  • Viral Proteins / immunology*
  • Viral Proteins / metabolism

Substances

  • Antibodies, Viral
  • Epitopes
  • Immunoglobulin A
  • Immunoglobulin G
  • Recombinant Proteins
  • Viral Proteins
  • viral protein 1, rhinovirus
  • Intercellular Adhesion Molecule-1