2011 Annual Report 1a.Objectives (from AD-416) To explore the possibility of initial stage of host gene manipulation by developing RNA interference technology using primary lymphocytes. We will use RNAi technology to modulate IFN-y response since IFN-y is a key immunoregulatory cytokine of macrophages for mucosal immune response. 1b.Approach (from AD-416) Peripheral blood monocytes will be cultured in vitro and treated with siRNA using recently developed RNA interference (RNAi) technology to knockdown/silence post-transcriptional gene expression of chicken IFN-y. 3.Progress Report Cell-mediated immune response was targeted for RNAi technology to modulate IFN-G response. IFN-G is a key immunoregulatory cytokine of macrophages for mucosal immune response. Peripheral blood monocytes was cultured in vitro and treated with siRNA using recently developed RNAi technology to knockdown/silence post-transcriptional gene expression of chicken IFN-G. Three shRNAs produced fragments indicative of successful cloning and initial results showed partial reduction of IFN-G and IFN-a. In ovo manipulation to inhibit IFN-G induction was tried by injecting non-sense IFN-G gene at day 1 of embryo development. The results for IFN-G gene expression in developing embryos will be monitored using qRT-PCR. Progress is monitored by written progress reports, regular teleconferences and meetings. This research relates to NP103, C2, P.S.2c