Evaluation of Natural killer cell activity after coinfection of chickens with Infectious bursal disease and Avian influenza virus H9N2

Avian influenza virus subtype H9N2 is an endemic viral disease in middle east. On the otherhand Infectious bursal disease virus is a widespread infection in chicken which causes vast destruction of immune response to various diseases. Few studies on effect of the virus on innate immunity has been done. In this research we assesed NK cell activity after coinfection of chickens with IBD virus and Avian influenza virus H9N2. Thirthy two chickens were divided in four groups randomly. Group 1and 2 were inoculated with 103 CID50 IBD virus at one day old intra bursaly.at thirthy days old chickens in groups 1 and 3 were inoculated with 106 EID50 oculonasaly. Seven days after influenza virus infection chickens were euthanized and their spleens used for NK cell activity evaluation by Cytotoxicity Detection assay Kit plus LDH, Roche. The most activity was belonged to influenza infected groups but the differences was not Meaningful. So we can concluded that IBD and AI infection has no effect on NK activity.