Abstract
Infection with H5N6 highly pathogenic avian influenza virus caused high mortality in chickens, while ducks often appear to be asymptomatic. But, some recent H5Nx subtype viruses could cause high mortality in ducks. The variation between different species and the mechanisms by which some H5Nx viruses cause death in ducks requires investigation to identify the key processes in influenza susceptibility and pathogenesis. Here, we characterized two representative H5N6 viruses, A/Pavo cristatus/Jiangxi/JA1/2016 (JA1) and A/Anas crecca/shanghai/SH1/2016 (SH1), and compared their pathogenicity and expression profiles of immune-related genes in chickens and ducks to identify the elements of the host immune-related response that were involved in disease lethality. Results suggested that H5N6 HPAIVs had higher pathogenic and inflammatory effect in chickens than in ducks. Importantly, the TNF-α, IL-6, IFN-γ and iNOS levels were significantly higher in the lung of SH1 infected chickens compared to those of ducks. And we found higher systemic levels of IL-6 induced by JA1 in chickens than in ducks. In addition, our experiments demonstrated that JA1 was associated with greater pathogenicity in ducks were accompanied by the excessive expression of iNOS in the brain. These results are helpful to understand the relationship between the pathogenicity of H5N6 AIVs and inflammatory responses to them in chickens and ducks.
Highlights
Influenza viruses that originate from birds or swine have led to four pandemics since 1918
Putative amino acid sequences were compared between the two H5N6 influenza viruses, JA1 and SH1, to reveal any relationship between pathogenicity in chicken duck and the amino acid sequences of the viruses (Table 1; Supplementary Table S11)
Our results revealed that the mRNA expression profiles of innate immune gene displayed different patterns in chickens and ducks. We found that both two H5N6 HPAIVs (JA1 and SH1) were highly pathogenic in chickens
Summary
Influenza viruses that originate from birds or swine have led to four pandemics since 1918. Seasonal influenza viruses, such as H1N1 and H3N2, result in 250,000–500,000 deaths annually worldwide (Krammer et al, 2018). Highly pathogenic avian influenza viruses (HPAIVs, including H7N9, H5N1, and H5N6 subtypes) pose an ongoing threat to the animal and human health (Su et al, 2017). Comparative analyses between natural hosts (e.g., ducks) and spillover hosts (e.g., chickens) and understanding the mechanisms by which some H5Nx viruses cause death in ducks will help to identify the key processes in influenza susceptibility and pathogenesis
Sign-in/Register to view highlights & summary 
Published Version (
Free)
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 call