TRIM27-L INCREASES IFN-β SIGNALLING DOWNSTREAM OF dMAVS BUT NOT chMAVS
Lee Campbell, University of Alberta
Lee K. Campbell and Katharine E. Magor
University of Alberta, Department of Biological Sciences, Edmonton, AB
Tripartite motif (TRIM) proteins have been shown to be potent antiviral proteins and can restrict replication of viruses such as influenza A virus. It is currently not known if these proteins can inhibit influenza in its reservoir host, the duck. Ducks show remarkable resistance to morbidity and mortality of viral infection when compared to other species such as chickens. TRIM27-L is a gene found in the MHC-B locus of ducks but appears to have been lost in chickens. TRIM27-L was previously shown to increase IFN-β downstream of RIG-I signalling, however it is currently not known where this protein interacts within this pathway or if it defends against influenza infection. TRIM27-L was found to increase IFN-β signalling when transfected with dMAVS however it decreased this signalling when cotransfected with chMAVS. As chMAVS and dMAVs only share 58% identity we hypothesized that TRIM27-L is interacting differently with MAVS proteins from different species. TRIM27-L was found to not be protective against infection when overexpressed in chicken fibroblasts and interestingly cells transfected with TRIM27-L were more susceptible to virus. However, when cotransfected with RIG-I, TRIM27-L restricts viral replication in chicken fibroblasts beyond that of RIG-I alone. In the future, we will investigate the differences between chMAVS and dMAVS modification by TRIM27-L and use mass spectrometry to determine if other proteins are interacting with TRIM27-L in this pathway. These studies will help our understanding of TRIM protein evolution and regulation of innate immune function.