Characterization of neutralizing epitopes in antigenic site B of recently circulating influenza A(H3N2) viruses
Kerstin Beer
Mian Dai
Steven Howell
Pramila Rijal
Alain R Townsend
Yipu Lin
Stephen A Wharton
Rodney S Daniels
John W McCauley
10779/crick.12546593.v1
https://crick.figshare.com/articles/journal_contribution/Characterization_of_neutralizing_epitopes_in_antigenic_site_B_of_recently_circulating_influenza_A_H3N2_viruses/12546593
Influenza A(H3N2) viruses are associated with outbreaks worldwide and can cause disease with severe complications. The impact can be reduced by vaccination, which induces neutralizing antibodies that mainly target the haemagglutinin glycoprotein (HA). In this study we generated neutralizing mouse monoclonal antibodies (mAbs) against A/Victoria/361/2011 and identified their epitopes by generating and sequencing escape viruses. The epitopes are located in antigenic site B, which is near the receptor-binding site and is immunodominant in humans. Amino acid (aa) substitutions at positions 156, 158, 159, 189, 190 and 193 in antigenic site B led to reduced ability of mAbs to block receptor-binding. The majority of A(H3N2) viruses that have been circulating since 2014 are antigenically distinct from previous A(H3N2) viruses. The neutralization-sensitive epitopes in antigenic site B of currently circulating viruses were examined with these mAbs. We found that clade 3C.2a viruses, possessing an additional potential glycosylation site at HA1 position N158, were poorly recognized by some of the mAbs, but other residues, notably at position 159, also affected antibody binding. Through a mass spectrometric (MS) analysis of HA, the glycosylated sites of HA1 were established and we determined that residue 158 of HA1 was glycosylated and so modified a neutralization-sensitive epitope. Understanding and monitoring individual epitopes is likely to improve vaccine strain selection.
2020-06-26 09:39:28
Influenza
antigenic drift
monoclonal antibodies
Animals
Antibodies, Monoclonal
Antibodies, Neutralizing
Antibodies, Viral
Antigens, Viral
Epitopes
Ferrets
Glycosylation
Hemagglutinins, Viral
Humans
Influenza A Virus, H3N2 Subtype
Influenza, Human
Models, Molecular
Protein Conformation
McCauley FC001030
WIC
PRT
06 Biological Sciences
07 Agricultural and Veterinary Sciences
11 Medical and Health Sciences
Virology