Abstract
The H5 and H7N9 subtypes of highly pathogenic avian influenza viruses (HPAIVs) in China pose a serious challenge to public health and the poultry industry. In this study, a replication competent recombinant influenza A virus of the Í5N1 subtype expressing the H7 HA1 protein from a tri-cistronic NS segment was constructed. A heterologous dimerization domain was used to combine with the truncated NS1 protein of 73 amino acids to increase protein stability. H7 HA1, nuclear export protein coding region, and the truncated NS1 were fused in-frame into a single open reading frame via 2A self-cleaving peptides. The resulting PR8-H5-NS1(73)H7 stably expressed the H5 HA and H7 HA1 proteins, and exhibited similar growth kinetics as the parental PR8-H5 virus in vitro. PR8-H5-NS1(73)H7 induced specific hemagglutination inhibition (HI) antibody against H5, which was comparable to that of the combination vaccine of PR8-H5 and PR8-H7. The HI antibody titers against H7 virus were significantly lower than that by the combination vaccine. PR8-H5-NS1(73)H7 completely protected chickens from challenge with both H5 and H7 HPAIVs. These results suggest that PR8-H5-NS1(73)H7 is highly immunogenic and efficacious against both H5 and H7N9 HPAIVs in chickens.Highlights:- PR8-H5-NS1(73)H7 simultaneously expressed two HA proteins of different avian influenza virus subtypes.- PR8-H5-NS1(73)H7 was highly immunogenic in chickens.- PR8-H5-NS1(73)H7 provided complete protection against challenge with both H5 and H7N9 HPAIVs.
Highlights
H5N1 avian influenza viruses (AIVs) have circulated in more than 60 countries and have caused huge economic losses to the poultry industry worldwide (Swayne, 2012)
PR8-H5-non-structural protein 1 (NS1)(73)H7 completely protected chickens from challenge with both H5 and H7 highly pathogenic avian influenza viruses (HPAIVs). These results suggest that PR8-H5-NS1(73)H7 is highly immunogenic and efficacious against both H5 and H7N9 HPAIVs in chickens
A tri-cistronic NS-derived gene segment was designed in a single open reading frame consisting of NS1(1–73)Dmd, H7 HA1, and nuclear export protein (NEP) separated from each other via two different 2A self-cleaving peptides
Summary
H5N1 avian influenza viruses (AIVs) have circulated in more than 60 countries and have caused huge economic losses to the poultry industry worldwide (Swayne, 2012). The H5N1 AIVs have become enzootic in poultry and wild birds in China (including Hong Kong special administrative region [SAR]), Bangladesh, eastern India, Indonesia, Vietnam, and Egypt (Swayne et al, 2011). Sequence analyses of the HA genes have shown that H5 viruses have evolved into diverse clades and subclades (Li et al, 2010). Viruses in clades 2.3.2.1 and 2.3.4.4 continue to cocirculate in wild birds and poultry in several countries, while clade 7.2 viruses have been detected in chickens in several provinces in Northern China (Li et al, 2010). Recent molecular epidemiological surveys of AIVs have detected no clade 7.2 viruses and significant decreases in circulating clade 2.3.2.1 viruses since 2015 (data not published). Clade 2.3.4.4 viruses are the dominant epidemic strains
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
