Assessing cytokine responses in indigenous and exotic chicken breeds following velogenic Newcastle disease virus challenge

A challenge study was undertaken to study the cytokine responses in different chicken breeds i.e., White Leghorn, Aseel, Kadaknath and Nicobari at ten weeks by exposing them to 10^7.5 EID₅₀ of velogenic Newcastle disease virus (vNDV). End point PCR based gene expression analysis of interleukins (IL) and interferons (IFN) were done at two days post-challenge in both control and challenged birds before and after infection. Collection of spleen samples were done by employing humane sacrifice of birds two days post challenge. The genes macrophage migration inhibition factor, IL-1β, IL-2, IL-6 and IFN-γ were amplified using end point PCR and analysed using agarose gel electrophoresis for confirmation. Expression of the Interleukin-1β gene was higher in Aseel and Nicobari than in White Leghorn. Nicobari had a higher level of Interferon-γ gene expression than Aseel in response to NDV infection. Aseel demonstrated superior survival and activity, implying that the indigenous chicken breed is considered to have superior tolerance compared to Kadaknath, Nicobari and White Leghorn chickens.