2007 Annual Report 1a.Objectives (from AD-416) This collaborative project is to evaluate the interaction of avian influenza viruses with the chicken interferon (IFN) system in primary chicken embryonic cells that are highly responsive to: (1) the production of IFN upon infection with avian influenza viruses, and (2) the action of IFN against these same viruses. 1b.Approach (from AD-416) A broad spectrum of low pathogenic avian influenza viruses will be evaluated for the ability to induce and resist the action of interferon in chicken cells under standardized cell culture conditions. The generation and analysis of standard IFN induction dose (multiplicity)-response (IFN yield) curves permits an accurate assessment of the maximum IFN-inducing capacity of each influenza virus isolate along with a measure of the number of particles in the virus preparation that contribute to the yield of IFN. These data will be compared with sequences of the NS1 protein in particular to correlate the genetic and phylogenetic characteristics of the viruses relative to IFN induction and action. Two phenotypes of these viruses can be measured: (1) IFN-inducing particle [IFP] activity, and (2) IFN induction-suppressing activity. The genetic information from sequencing will be evaluated to seek meaningful relationships between genotype and phenotypic expression as phylogenetic markers. 3.Progress Report This report documents research conducted under a specific cooperative agreement between ARS and the University of Connecticut. Additional details of research can be found in the report for the in-house associated project 6612-32000-048-00D, Application of Biological and Molecular Techniques to the Diagnosis and Control of Avian Influenza and other Emerging Poultry Pathogens, and 6612-32000-051-00X, Emergency Veterinary Medical Research on Vaccines, Environmental Surveillance, Genomics, and Biosecurity for H5N1 High Pathogenicity Avian Influenza. The agreement was recently completed and the project is just beginning. Ten low pathogenic avian influenza viruses have been transferred to the University of Connecticut that will be analyzed for induction and response to interferon. MONITORING: Progress is monitored by regular email communications, phone calls, and by meetings.