Liji Xie, Zhixun Xie*, Sheng Wang, Jiaoling Huang, Xianwen Deng, Zhiqin Xie, Sisi Luo, Tingting Zeng,
Yanfang Zhang,Minxiu Zhang

Abstract Avian reovirus (ARV) is a member of the genus Orthoreovirus in the family Reoviridae and causes a severe syndrome including viral arthritis that leads to considerable losses in the poultry industry. Innate immunity plays a significant role in host defense against ARV. Here, we explored the interaction between ARV and the host innate immune system by measuring mRNA expression levels of several genes associated with the MDA5 signaling pathway. The results showed that expression peaks for MDA5, MAVS, TRAF3, TRAF6, IRF7, IKKɛ, TBK1 and NF-κB occurred at 3 days postinfection (dpi). Moreover,type I IFN (IFN-α, IFN-β) and IL-12 expression levels peaked at 3 dpi, while type II IFN (IFN-γ), IL-6, IL-17 and IL-18 expression reached a maximum level at 1 dpi. IL-8 changed at 5 dpi, and IL-1β and TNF-α changed at 7 dpi. Interestingly,several key IFN-stimulated genes (ISGs), including IFITM1, IFITM2, IFITM5, Mx1 and OASL, were simultaneouslyupregulated and reached maximum values at 3 dpi. These data indicate that the MDA5 signaling pathway and innate immunecytokines were induced after ARV infection, which would contribute to the ARV-host interaction, especially at the earlyinfection stage.

https://doi.org/10.1007/s00705-019-04340-8