Differential Response of Resistant and Susceptible Chicken Lines to Newcastle Disease Virus in the Trachea and Lung

Newcastle disease has devastating impacts on poultry production in the developing world. This study aims to characterize differential responses between resistant (Fayoumi) and susceptible (Leghorn) chicken lines challenged with a lentogenic Newcastle Disease Virus (NDV) strain via the eyes and nostrils. Tissues were collected from three-week-old challenged and control birds from each line at 2, 6, and 10 days-post-infection (dpi). RNA sequencing was performed on tracheal epithelial cells and lungs, major sites of NDV pathogenesis. The largest numbers of differentially expressed (DE) genes were seen in both lines and tissues at 2 dpi and decreased in number from 2 to 10 dpi. Of the two tissues, line has a larger impact on the variance of the phenotype in the lung. Gene set enrichment analysis (GSEA) showed the important role of leukocytes in the trachea when comparing DE genes found between the Leghorns and Fayoumis in the challenged group.  The GSEA of the lung showed many gene-ontology (GO) terms involved in cellular immunity. IL-8 related GO terms appeared in both tissues suggesting this chemokine has a significant role and deserves additional exploration. Further analysis is required to determine pathways associated with resistance to NDV. This research is the first step in identifying genes and pathways involved in resistance to breed chickens more resistant to NDV in under-developed countries where they rely on village chickens for adequate protein in their diet, as well as their livelihood.

Support: USAID Feed the Future Innovation Lab for Genomics to Improve Poultry and Hatch project #5357.