Recombinant influenza H9N2 virus with a substitution of H3 hemagglutinin transmembrane domain showed enhanced immunogenicity in mice and chicken

Yun Zhang,Kang Liu,Ying Wei,Yongchang Cao,Ran Li,Chunyi Xue,Jing Zheng,Mengjiao Huang,Yang Wang,Qiliang Liu

doi:10.1038/s41598-017-18054-x

Yun Zhang, Kang Liu + Show 8 more

Open Access

https://doi.org/10.1038/s41598-017-18054-x

Copy DOI

Journal: Scientific Reports	Publication Date: Dec 1, 2017
Citations: 33	License type: open-access

Affiliation: Sun Yat-sen University

Abstract

In recent years, avian influenza virus H9N2 undergoing antigenic drift represents a threat to poultry farming as well as public health. Current vaccines are restricted to inactivated vaccine strains and their related variants. In this study, a recombinant H9N2 (H9N2-TM) strain with a replaced H3 hemagglutinin (HA) transmembrane (TM) domain was generated. Virus assembly and viral protein composition were not affected by the transmembrane domain replacement. Further, the recombinant TM-replaced H9N2-TM virus could provide better inter-clade protection in both mice and chickens against H9N2, suggesting that the H3-TM-replacement could be considered as a strategy to develop efficient subtype-specific H9N2 influenza vaccines.

Highlights

H9N2 avian influenza virus was first isolated in turkeys in 19661
We generated a recombinant H9N2 wild type strain (H9N2-WT) and a recombinant H9N2 strain with a H3-TM domain replacement (H9N2-TM) utilizing reverse genetics system
To understand whether change of transmembrane (TM) domain can affect virus structure, we first observed the morphology of TM-replaced viruses rescued by reserve genetics

Summary

Introduction

H9N2 avian influenza virus was first isolated in turkeys in 19661 Since it became prevalent in poultry farming worldwide, resulting in egg production reduction and high mortality when co-infected with other pathogens[2,3]. Substitution of the TM domain showed an abolishment of receptor binding and membrane fusion, leading to a failure of virus entry into the cells[14,15] This domain was found to be important for biological characteristics of the influenza viruses, such as viral replication, virulence and pathogenicity[16,17,18]. Our results showed that the replacement of transmembrane (TM) domain did not affect the virus assembly and viral protein composition in the recombinant H9N2 viruses. The TM-replaced H9N2-TM strain exhibited better protection in both mice and chicken when challenged against different phylogenetic H9N2 clades

Methods

Results

Conclusion