Species-Specific Differences in Innate Immune Responses of Chicken and Duck Embryonic Fibroblasts to Avian Influenza Virus Infections

In this study, we compared the virus permissiveness and host transcriptomic responses in chicken DF-1 and duck CCL141 embryonic fibroblasts following infection with low pathogenicity avian influenza (LPAI) A/turkey/England/198/09 (H6N1) and high pathogenicity avian influenza (HPAI) A/chicken/Scotland/054477/2021 (H5N1-AIV09). Duck cells exhibited reduced permissiveness for both LPAI and HPAI virus replication compared to chicken cells, and this was associated with notable differences in the innate immune responses of each species. Specifically, duck cells showed higher basal and infection-induced caspase 3/7 activity in response to both viruses, indicating elevated apoptotic activity that may contribute to enhanced antiviral defense. In contrast, chicken cells demonstrated significant downregulation of DEAD-box RNA helicases during H5N1-AIV09 infection, which suggests a weaker innate immune sensing response. Additionally, chicken cells exhibited more transcriptional activation of NF-κB-related genes during infection, which likely drives a stronger pro-inflammatory response and prolonged cell survival compared to duck cells.

Lamyaa Al-Dalawi, Adam Blanchard, Michael Clark, Leah V. Goulding and Kin-Chow Chang

Notable outbreaks, field and molecular epidemiology, and surveillance in poultry