Multiple adaptive amino acid substitutions increase the virulence of a wild waterfowl-origin reassortant H5N8 avian influenza virus in mice

Zhijun Yu; Kaihui Cheng; Weiyang Sun; Xinghai Zhang; Xianzhu Xia; Yuwei Gao

doi:10.1016/j.virusres.2017.11.002

Multiple adaptive amino acid substitutions increase the virulence of a wild waterfowl-origin reassortant H5N8 avian influenza virus in mice

Virus Res. 2018 Jan 15:244:13-20. doi: 10.1016/j.virusres.2017.11.002. Epub 2017 Nov 4.

Authors

Zhijun Yu¹, Kaihui Cheng², Weiyang Sun³, Xinghai Zhang³, Xianzhu Xia⁴, Yuwei Gao⁵

Affiliations

¹ Institute of Poultry Science, Shandong Academy of Agricultural Sciences, Jinan, 250023, China. Electronic address: zhijun0215@gmail.com.
² Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, Jinan, 250132, China.
³ Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122, China.
⁴ Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. Electronic address: xiaxzh@cae.cn.
⁵ Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. Electronic address: gaoyuwei@gmail.com.

PMID: 29113821
DOI: 10.1016/j.virusres.2017.11.002

Abstract

A novel H5N8 highly pathogenic avian influenza virus (HPAIV) caused poultry outbreaks in the Republic of Korea in 2014. The novel H5N8 HPAIV has spread to Asia, Europe, and North America and caused great public concern from then on. Here, we generated mouse-adapted variants of a wild waterfowl-origin H5N8 HPAIV to identify adaptive mutants that confer enhanced pathogenicity in mammals. The mouse lethal doses (MLD₅₀) of the mouse-adapted variants were reduced 31623-fold compared to the wild-type (WT) virus. Mouse-adapted variants displayed enhanced replication in vitro and in vivo, and expanded tissue tropism in mice. Sequence analysis revealed four amino acid substitutions in the PB2 (E627K), PA (F35S), HA (R227H), and NA (I462V) proteins. These data suggest that multiple amino acid substitutions collaboratively increase the virulence of a wild bird-origin reassortant H5N8 HPAIV and cause severe disease in mice.

Keywords: Avian influenza virus; H5N8; Mice; Virulence; Wild waterfowl.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Substitution*
Animals
Anseriformes / virology
Disease Outbreaks*
Female
Gene Expression
Hemagglutinin Glycoproteins, Influenza Virus / genetics
Hemagglutinin Glycoproteins, Influenza Virus / metabolism
Influenza A Virus, H5N8 Subtype / genetics*
Influenza A Virus, H5N8 Subtype / pathogenicity
Influenza in Birds / epidemiology*
Influenza in Birds / pathology
Influenza in Birds / virology
Mice
Mice, Inbred BALB C
Mutation
Neuraminidase / genetics
Neuraminidase / metabolism
Orthomyxoviridae Infections / mortality
Orthomyxoviridae Infections / pathology*
Orthomyxoviridae Infections / virology
RNA-Dependent RNA Polymerase / genetics
RNA-Dependent RNA Polymerase / metabolism
Reassortant Viruses / genetics*
Reassortant Viruses / pathogenicity
Survival Analysis
Viral Load
Viral Proteins / genetics
Viral Proteins / metabolism
Viral Tropism
Virulence
Virus Replication

Substances

Hemagglutinin Glycoproteins, Influenza Virus
PA protein, influenza viruses
PB2 protein, influenza virus
Viral Proteins
RNA-Dependent RNA Polymerase
NA protein, influenza A virus
Neuraminidase