Oral Poster & Poster Presentation 9th Australasian Virology Society Meeting 2017

Phosphoinositides are redistributed and upregulated in Mouse Norovirus Infection (#106)

Nathan D Kenney 1 , Tanya B O'Donnell 1 , Jason M MacKenzie 1
  1. University of Melbourne, Melbourne, VIC, Australia

Human Norovirus (HNV) is a (+)RNA virus which is the leading cause of gastorenteritis in the world. As HNV is unable to be cultured in the lab, Mouse Norovirus (MNV) provides a model for investigating HNV pathogenesis. The intracellular replication of Norovirus and arguably all (+)RNA viruses is dependent on host resources, including proteins, metabolites and lipids. (+)RNA viruses commandeer organelle membranes to construct viral Replication Complexes (RO), which are necessary for efficient replication. Here we investigate the host lipid utilization by MNV and identify the key host proteins that facilitate the viral-induced subversion of lipid biosynthesis pathways. In particular, we focus on the host lipid Phosphotidylinositol 4-Phosphate (PI4P) and its contribution to efficient virus replication. PI4P is normally present in plasma and organelle membranes, and has been shown to be utilized in replication of other (+)RNA viruses. Previously, PI4P and PI4P kinases have been shown to localize to sites of MNV replication. Here we demonstrate that PI4P is upregulated during MNV infection, and the responsible kinase is PI4KIII3α. This is done by using chemical inhibitors of PI4P kinases in combination with immunofluorescent staining, which reconfirm colocalization between PI4P and MNV NS4, as well as by qPCR and western blots which show virus quantity reduction when PI4KIII3α is inhibited. We hypothesize that identification of key host components that facilitate virus replication will enable the development of compounds with antiviral potential.