Single cell RNA-seq in chicken's lung and DF-1 cell line

Newcastle disease virus (NDV) is an avian paramyxovirus that causes major economic losses to the poultry industry around the world, with NDV pathogenicity varying due to strain virulence differences. However, the impact of intracellular viral replication and the heterogeneity of host responses among cell types are unknown. Here, we investigated the heterogeneity of lung tissue cells in response to NDV infection in vivo and that of chicken embryo fibroblast cell line DF-1 to NDV infection in vitro using single-cell RNA sequencing. Three-day-old SPF chicks was challenged with the LaSota lentogenic strain of NDV (200 μl of 108 50% egg infectious dose [EID50]) by ocular and nasal routes (50 μl into each eye and nostril), whereas the other group was challenged with the highly virulent Herts/33 strain of NDV (200 μl of 103 EID50). The control group was treated with 200 μl phosphate-buffered saline (PBS) by the same routes. Chicks were sacrificed after 3 days of treatment. Finally, two chicks in each group (n = 2/each group) were used for single-cell sorting. DF-1 cell line infected with 1 MOI Herts/33 after 12 hours were uesd for single-cell sorting.