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Updated: May 4, 2026
Detection of Neutralization-sensitive Epitopes in Antigens Displayed on Virus-Like Particle VLP-Based Vaccines Using a Capture Assay
Published on: February 10, 2022
Preparation and properties of a papillomavirus infectious intermediate and its utility for neutralization studies
Joshua W Wang1, Subhashini Jagu1, Kihyuck Kwak1
1Department of Pathology, The Johns Hopkins University, Baltimore, MD 21231, USA.
Abstract:
We show that minor capsid protein L2 is full length in clinical virion isolates and prepare furin-cleaved pseudovirus (fcPsV) as a model of the infectious intermediate for multiple human papillomavirus (HPV) types. These fcPsV do not require furin for in vitro infection, and are fully infectious in vivo. Both the γ-secretase inhibitor XXI and carrageenan block fcPsV infection in vitro and in vivo implying that they act after furin-cleavage of L2. Despite their enhanced exposure of L2 epitopes, vaccination with fcPsV particles fails to induce L2 antibody, although L1-specific responses are similar to PsV with intact L2. FcPsV can be applied in a simple, high-throughput neutralization assay that detects L2-specific neutralizing antibodies with >10-fold enhanced sensitivity compared with the PsV-based assay. The PsV and fcPsV-based assays exhibit similar sensitivity for type-specific antibodies elicited by L1 virus-like particles (VLP), but the latter improves detection of L1-specific cross-type neutralizing antibodies.
Insights
Furin-cleaved pseudovirus (fcPsV) models human papillomavirus (HPV) infection. FcPsV enhance antibody detection but fail to elicit L2 antibodies upon vaccination.
Area of Science:
- Virology
- Immunology
- Vaccine Development
Background:
- Minor capsid protein L2 is full-length in clinical human papillomavirus (HPV) virions.
- Furin cleavage of L2 is a critical step in HPV infection.
- A model for the infectious intermediate is needed to study HPV entry and develop vaccines.
Purpose of the Study:
- To create and characterize furin-cleaved pseudovirus (fcPsV) as a model of the infectious HPV intermediate.
- To investigate the role of L2 cleavage in HPV infection and immune response.
- To develop improved assays for detecting HPV-specific neutralizing antibodies.
Main Methods:
- Preparation of fcPsV for multiple HPV types.
- In vitro and in vivo infection assays using fcPsV.
- Testing the efficacy of γ-secretase inhibitor XXI and carrageenan on fcPsV infection.
- Vaccination studies with fcPsV and pseudovirus (PsV) with intact L2.
- Development and comparison of neutralization assays using PsV and fcPsV.
Main Results:
- FcPsV are infectious in vitro and in vivo without requiring furin.
- γ-secretase inhibitor XXI and carrageenan inhibit fcPsV infection post-furin cleavage.
- Vaccination with fcPsV does not induce L2 antibodies, though L1 responses are similar to PsV.
- FcPsV enable a high-throughput assay with >10-fold enhanced sensitivity for L2-specific neutralizing antibodies.
- FcPsV improve the detection of L1-specific cross-type neutralizing antibodies compared to PsV.
Conclusions:
- FcPsV serve as a valuable model for studying HPV infection intermediates.
- The findings provide insights into the mechanisms of HPV entry and antibody evasion.
- FcPsV-based assays offer enhanced sensitivity for detecting neutralizing antibodies, crucial for vaccine efficacy assessment.
