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Updated: May 17, 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
Monoclonal antibodies recognizing cross-neutralization epitopes in human papillomavirus 16 minor capsid protein L2
Sari Nakao1, Seiichiro Mori, Kazunari Kondo
1Pathogen Genomics Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Abstract:
Antisera induced by immunization of rabbits with the synthetic peptide P56/75, which has the amino acid (aa) sequence from aa56 to aa75 of HPV16 L2, neutralize pseudovirions and raft-virions of multiple high-risk HPV types, indicating that cross-neutralization epitopes are present in the aa56-75 region. We generated two mouse monoclonal antibodies (MAb): MAb13B and MAb24B recognizing the regions of aa64-73 and aa58-64, respectively. The neutralization assay using pseudovirions of HPV16, 18, 31, 33, 35, 51, 52 and 58 showed that MAb13B neutralized HPV16, 18, and 51, and MAb24B neutralized all the types tested. The mixture of MAb13B and MAb24B neutralized HPV16, 18, and 51 pseudovirions more efficiently than each of the MAbs alone. The data indicate that there are at least two cross-neutralization epitopes in the aa56-75 region and that an antigen capable of presenting the two cross-neutralization epitopes would be a good vaccine candidate for a broad-spectrum of HPVs.
Insights
Rabbit antisera targeting the HPV16 L2 peptide P56/75 neutralized multiple high-risk human papillomavirus (HPV) types. Mouse monoclonal antibodies targeting distinct regions of this peptide also demonstrated broad-spectrum HPV neutralization, suggesting a promising vaccine candidate.
Area of Science:
- Virology
- Immunology
- Vaccine Development
Background:
- Human papillomavirus (HPV) infections are a major cause of cervical and other cancers.
- Developing broadly protective HPV vaccines is a significant public health goal.
- The L2 protein of HPV contains conserved regions potentially targeted for cross-neutralization.
Purpose of the Study:
- To investigate the cross-neutralizing potential of antibodies targeting the HPV16 L2 amino acid (aa) 56-75 region.
- To identify specific epitopes within this region responsible for broad HPV type neutralization.
- To evaluate the efficacy of monoclonal antibodies (MAbs) targeting these epitopes for vaccine development.
Main Methods:
- Immunization of rabbits with a synthetic peptide (P56/75) corresponding to HPV16 L2 aa56-75.
- Generation and characterization of two mouse monoclonal antibodies (MAbs), MAb13B (aa64-73) and MAb24B (aa58-64).
- Neutralization assays using pseudovirions of multiple high-risk HPV types (HPV16, 18, 31, 33, 35, 51, 52, 58).
Main Results:
- Antisera against P56/75 neutralized multiple HPV types, confirming cross-neutralizing epitopes in the aa56-75 region.
- MAb13B neutralized HPV16, 18, and 51; MAb24B neutralized all tested HPV types.
- A combination of MAb13B and MAb24B showed enhanced neutralization of HPV16, 18, and 51 pseudovirions.
Conclusions:
- The HPV16 L2 aa56-75 region contains at least two distinct cross-neutralization epitopes.
- Monoclonal antibodies targeting these epitopes exhibit broad-spectrum HPV neutralization capabilities.
- An antigen presenting these epitopes is a potential candidate for a broad-spectrum HPV vaccine.
