Adaptation of influenza B virus by serial passage in human airway epithelial cells

• Published in: Virology (New York, N.Y.) N.Y.), 2020-10, Vol.549, p.68-76
• Main Authors: Ilyushina, Natalia A., Lee, Nicolette, Lugovtsev, Vladimir Y., Kan, Anastasia, Bovin, Nicolai V., Donnelly, Raymond P.
• Format: Article
• Language: English
• Subjects: Adaptation; Animals; Cell Line; Dogs; Epithelial Cells; Gene Expression Regulation, Viral; HEK293 Cells; Hemagglutination Inhibition Tests; Hemagglutinin receptor specificity; Hemagglutinins, Viral - genetics; Hemagglutinins, Viral - metabolism; Host-Pathogen Interactions - genetics; Human airway epithelial cells; Humans; Influenza B virus; Influenza B virus - genetics; Influenza B virus - growth & development; Influenza B virus - metabolism; Madin Darby Canine Kidney Cells; Mutation; Neuraminidase - genetics; Neuraminidase - metabolism; Neuraminidase activity; Polymerase activity; Serial Passage - methods; Signal Transduction; Viral Matrix Proteins - genetics; Viral Matrix Proteins - metabolism; Viral Proteins - genetics; Viral Proteins - metabolism; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2020.08.004

Influenza B viruses cause seasonal epidemics and are a considerable burden to public health. To understand their adaptation capability, we examined the genetic changes that occurred following 15 serial passages of two influenza B viruses, B/Brisbane/60/2008 and B/Victoria/504/2000, in human epithelial cells. Thirteen distinct amino acid mutations were found in the PB1, PA, hemagglutinin (HA), neuraminidase (NA), and M proteins after serial passage in the human lung epithelial cell line, Calu-3, and normal human bronchial epithelial (NHBE) cells. These changes were associated with significantly decreased viral replication levels. Our results demonstrate that adaptation of influenza B viruses for growth in human airway epithelial cells is partially conferred by selection of HA1, NA, and polymerase mutations that regulate receptor specificity, functional compatibility with the HA protein, and polymerase activity, respectively. •Adaptive changes correlate with decreased viral replication.•D197T HA1 mutation decreased binding affinity for “avian-like” 3′SLN glycan.•Double G141R/G237E HA1 mutation significantly decreased binding to α2,6 glycans.•G346E NA mutation reduced NA activity in catalyzing 3ʹSL or 6ʹSL glycans.•D120G PB1 and V625A PA substitutions enhanced viral polymerase activity.