INVESTIGATING THE ROLE OF DDX17 IN ANTIVIRAL INNATE IMMUNE SIGNALLING DURING VIRAL INFECTION AND ITS IMPACT ON VIRUS SPREAD AND REPLICATION (360G-Wellcome-211893_Z_18_Z)

The host DEAD box RNA helicases are master regulators of pathogen RNA and DNA sensing dependent IRF3 signalling and are crucial for host survival and infection outcome in response to a multitude of both viral and bacterial pathogens. Here we report the DEAD box RNA helicase DDX17 as a novel pathogen recognition receptor essential for IRF3 driven IFNbeta expression in response to immunostimulatory DNA and dsRNA. Our current data maps DDX17 to act independent to the canonical IRF3 signalling cascade at the level of gene transcription, independent of IRF3 phosphorylation. We hypothesise that DDX17 may regulate beta-catenin nuclear shuttling, an essential IRF3 transcriptional cofactor. We aim to investigate the impact of DDX17 on beta-catenin activation and phosphorylation status as well as subcellular localisation following stimulation of WT or KO MEFs. Furthermore, we aim to investigate the biological relevance in viral infection following vaccinia virus and herpes simplex virus type 1 infection of WT and KO MEFs through quantification of viral replication and spread as well as IRF3 pathway activation. This project will contribute to understanding the role of DDX17 in innate immunity and host-pathogen interaction with implications in the immunological understanding of viral infection. Key words: DDX17, IRF3, IFNbeta, helicase