Passage of influenza A/H3N2 viruses in human airway cells removes artefactual variants associated with neuraminidase-mediated binding

[tetano]

J Gen Virol. 2019 Nov 8. doi: 10.1099/jgv.0.001348. [Epub ahead of print] Passage of influenza A/H3N2 viruses in human airway cells removes artefactual variants associated with neuraminidase-mediated binding.

Brown JC^1,2, Barclay WS¹, Galiano M^3,4, Harvey R^3,2.
Author information

1 Department of Infectious Disease, Imperial College, London, UK. 2 National Institute for Biological Standards and Control, Potters Bar, UK. 3 Present address: WHO Collaborating Centre for Reference and Research on Influenza, Francis Crick Institute, London, UK. 4 Public Health England, London, UK.

Abstract

Serological assays with modern influenza A/H3N2 viruses have become problematic due to the progressive reduction in the ability of viruses of this subtype to bind and agglutinate red blood cells (RBCs). This is due to reduced ability of the viral haemagglutinin (HA) glycoprotein to bind to the sialic acid-containing receptors presented by these cells. Additionally, as a result of reduced HA-mediated binding in cell culture, modern A/H3N2 viruses often acquire compensatory mutations during propagation that enable binding of cellular receptors through their neuraminidase (NA) surface protein. Viruses that have acquired this NA-mediated binding agglutinate RBCs through their NA, confusing the results of serological assays designed to assess HA antigenicity. Here we confirm with a large dataset that the acquisition of mutations that confer NA binding of RBCs is a culture artefact, and demonstrate that modern A/H3N2 isolates with acquired NA-binding mutations revert to a clinical-like NA sequence after a single passage in human airway epithelial (HAE) cells.


KEYWORDS:

H3N2; haemagglutination; influenza; neuraminidase; serology; vaccine

PMID: 31702542 DOI: 10.1099/jgv.0.001348