Open AccessInfluenza virus‐like particles harboring H9N2 HA and NA proteins induce a protective immune response in chicken
Author(s) -
Li Xin,
Ju Houbin,
Liu Jian,
Yang Dequan,
Qi Xinyong,
Yang Xianchao,
Qiu Yafeng,
Zheng Jie,
Ge Feifei,
Zhou Jinping
Publication year - 2017
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12472
Subject(s) - virology , antigenicity , neuraminidase , influenza a virus subtype h5n1 , virus , hemagglutinin (influenza) , biology , hemagglutination assay , microbiology and biotechnology , titer , antigen , influenza vaccine , virus like particle , influenza a virus , immunology , gene , biochemistry , recombinant dna
Background Avian influenza viruses represent a growing threat of an influenza pandemic. The co‐circulation of multiple H9N2 genotypes over the past decade has been replaced by one predominant genotype—G57 genotype, which displays a changed antigenicity and improved adaptability in chickens. Effective H9N2 subtype avian influenza virus vaccines for poultry are urgently needed. Objective In this study, we constructed H9N2 subtype avian influenza virus‐like particle ( VLP ) and evaluated its protective efficacy in specific pathogen‐free ( SPF ) chickens to lay the foundation for developing an effective vaccine against influenza viruses. Methods Expression of influenza proteins in VLP s was confirmed by Western blot, hemagglutination inhibition ( HI ), and neuraminidase inhibition ( NI ). The morphology was observed by electron microscopy. A group of 15 three‐week‐old SPF chickens was divided into three subgroups of five chickens immunized with VLP , commercial vaccine, and PBS . Challenge study was performed to evaluate efficacy of VLP vaccine. Results and Conclusions The hemagglutinin ( HA ) and neuraminidase ( NA ) proteins were co‐expressed in the infected cells, self‐assembled, and were released into the culture medium in the form of VLP s of diameter ~80 nm. The VLP s exhibited some functional characteristics of a full influenza virus, including hemagglutination and neuraminidase activity. In SPF chickens, the VLP s elicited serum antibodies specific for H9N2 and induced a higher HI titer (as detected by a homologous antigen) than did a commercial H9N2 vaccine (A/chicken/Shanghai/F/1998). Viral shedding from VLP vaccine subgroup was reduced compared with commercial vaccine subgroup and control subgroup.