Identification and Characterization of Novel Antibody Epitopes on the N2 Neuraminidase

mSphere. 2021 Feb 10;6(1):e00958-20. doi: 10.1128/mSphere.00958-20.


The influenza virus neuraminidase (NA) is becoming a focus for novel vaccine designs. However, the epitopes of human anti-NA antibodies have been poorly defined. Using a panel of 10 anti-N2 monoclonal antibodies (MAbs) that bind the H3N2 virus A/Switzerland/9715293/2013, we generated five escape mutant viruses. These viruses contained mutations K199E/T, E258K, A272D, and S331N. We found that mutations at K199 and E258 had the largest impact on MAb binding, NA inhibition and neutralization activity. In addition, a natural isolate from the 2017-2018 season was found to contain the E258K mutation and was resistant to numerous antibodies tested. The mutation S331N, was identified in virus passaged in the presence of antibody; however, it had little impact on MAb activity and greatly decreased viral fitness. This information aids in identifying novel human MAb epitopes on the N2 and helps with the detection of antigenically drifted NAs.IMPORTANCE The influenza virus neuraminidase is an emerging target for universal influenza virus vaccines. However, in contrast to influenza virus hemagglutinin, we know little about antibody epitopes and antigenic sites on the neuraminidase. Characterizing and defining these sites is aiding vaccine development and helping to understand antigenic drift of NA.

Keywords: N2; epitopes; influenza; mAb; neuraminidase.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • A549 Cells
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / metabolism*
  • Antibodies, Viral / immunology
  • Antibodies, Viral / metabolism*
  • Antigens, Viral / immunology
  • Dogs
  • Epitopes / genetics*
  • Epitopes / immunology*
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology
  • Humans
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza A Virus, H3N2 Subtype / immunology*
  • Influenza Vaccines / immunology
  • Madin Darby Canine Kidney Cells
  • Mutation
  • Neuraminidase / genetics
  • Neuraminidase / immunology*
  • Viral Proteins / genetics
  • Viral Proteins / immunology*


  • Antibodies, Monoclonal
  • Antibodies, Viral
  • Antigens, Viral
  • Epitopes
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Influenza Vaccines
  • Viral Proteins
  • Neuraminidase