Measurement of neutralizing serum antibodies of patients vaccinated with human papillomavirus L1 or L2-based immunogens using furin-cleaved HPV Pseudovirions

PLoS One. 2014 Jul 7;9(7):e101576. doi: 10.1371/journal.pone.0101576. eCollection 2014.

Abstract

Antibodies specific for neutralizing epitopes in either Human papillomavirus (HPV) capsid protein L1 or L2 can mediate protection from viral challenge and thus their accurate and sensitive measurement at high throughput is likely informative for monitoring response to prophylactic vaccination. Here we compare measurement of L1 and L2-specific neutralizing antibodies in human sera using the standard Pseudovirion-Based Neutralization Assay (L1-PBNA) with the newer Furin-Cleaved Pseudovirion-Based Neutralization Assay (FC-PBNA), a modification of the L1-PBNA intended to improve sensitivity towards L2-specific neutralizing antibodies without compromising assay of L1-specific responses. For detection of L1-specific neutralizing antibodies in human sera, the FC- PBNA and L1-PBNA assays showed similar sensitivity and a high level of correlation using WHO standard sera (n = 2), and sera from patients vaccinated with Gardasil (n = 30) or an experimental human papillomavirus type 16 (HPV16) L1 VLP vaccine (n = 70). The detection of L1-specific cross-neutralizing antibodies in these sera using pseudovirions of types phylogenetically-related to those targeted by the L1 virus-like particle (VLP) vaccines was also consistent between the two assays. However, for sera from patients (n = 17) vaccinated with an L2-based immunogen (TA-CIN), the FC-PBNA was more sensitive than the L1-PBNA in detecting L2-specific neutralizing antibodies. Further, the neutralizing antibody titers measured with the FC-PBNA correlated with those determined with the L2-PBNA, another modification of the L1-PBNA that spacio-temporally separates primary and secondary receptor engagement, as well as the protective titers measured using passive transfer studies in the murine genital-challenge model. In sum, the FC-PBNA provided sensitive measurement for both L1 VLP and L2-specific neutralizing antibody in human sera. Vaccination with TA-CIN elicits weak cross-protective antibody in a subset of patients, suggesting the need for an adjuvant.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing / blood*
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / blood
  • Antibodies, Viral / immunology
  • Antibody Specificity
  • Capsid Proteins / immunology
  • Capsid Proteins / metabolism
  • Furin / metabolism*
  • Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18
  • Humans
  • Neutralization Tests / methods*
  • Neutralization Tests / standards
  • Oncogene Proteins, Viral / immunology
  • Oncogene Proteins, Viral / metabolism
  • Papillomaviridae / immunology
  • Papillomavirus Vaccines / immunology*
  • Papillomavirus Vaccines / metabolism*
  • Proteolysis
  • Reference Standards
  • Vaccination*
  • Virion / immunology*

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Capsid Proteins
  • HPV L1 protein, Human papillomavirus
  • Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18
  • Oncogene Proteins, Viral
  • Papillomavirus Vaccines
  • Furin