Neutralizing antibody PR8-23 targets the footprint of the sialoglycan receptor binding site of H1N1 hemagglutinin

Influenza virus cause seasonal influenza epidemic and seriously sporadic influenza pandemic outbreaks. Hemagglutinin (HA) is an important target in the therapeutic treatment and diagnostic detection of the influenza virus. Variation in the sialic acid receptor binding site leads to strain-specific binding and results in different binding modes to the host receptors. Here, we evaluated the neutralizing activity and hemagglutination inhibition activity of a prepared murine anti-H1N1 monoclonal antibody PR8-23. Then we identified the epitope peptide of antibody PR8-23 by phage display technique from phage display peptide libraries. The identified epitope, 63-IAPLQLGKCNIA-74, containing two alpha-helix and two beta-fold located at the footprint of the sialoglycan receptor on the RBS in the globular head domain of HA. It broads the growing arsenal of motifs for the amino acids on the globular head domain of HA in sialic acid receptor binding site and neutralizing antibody production.

Automated summary

This study evaluated the neutralizing and hemagglutination inhibition activity of a murine anti-H1N1 monoclonal antibody, and identified its epitope peptide through phage display technique. The identified epitope contains key amino acids for sialic acid receptor binding in HA, contributing to the production of neutralizing antibodies.