Eduardo Suarez Lopez, University of Toronto

Eduardo Suarez-Lopez¹² Sophie-Marie Aicher¹³ Jonaton Kotwa² Simon Jeeves⁴ Federico DeAngelis⁵ Claire Jardine⁴ Karen Mossman⁶ Jeff Bowman⁷ Samira Mubareka¹². ¹ Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada ² Sunnybrook Research Institute, Toronto, ON, Canada ³ Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada ⁴ Department of Pathobiology, University of Guelph, Guelph, ON, Canada ⁵ Roslin Institute, Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, Scotland, UK ⁶ Department of Medicine, Centre for Discovery in Cancer Research and McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada ⁷ Wildlife Research and Monitoring Section, Ontario Ministry of Natural Resources, Peterborough, ON, Canada

Discovering & Evolving

Embecoviruses are a subgenus of betacoronaviruses that can infect a variety of mammalian species, including rodents, livestock, and humans. Well-studied viruses include mouse hepatitis virus, bovine coronavirus, and human coronavirus OC43, which causes seasonal respiratory disease in humans. We recently identified three novel Embecoviruses circulating in Peromyscus spp. in Ontario, Canada. [SA2.1]These viruses are phylogenetically related to known pathogenic Embecoviruses. Genome annotation of these novel coronaviruses suggests the presence of putative transcription-regulating sequences followed by multiple open reading frames, homologs of accessory proteins identified in other Embecoviruses. Understanding these accessory proteins is essential, as they have been shown to regulate virus-host interactions; for example, the NS2 protein in mouse hepatitis virus is type I interferon-induced and an antagonist that promotes viral replication. In this project, we aim to characterize the functional roles of putative accessory proteins. Mammalian expression constructs were designed to emulate the architecture of the viral subgenomic RNA transcript. These constructs will be transfected, and protein expression will be evaluated by Western blotting. To determine subcellular localization, immunofluorescence confocal microscopy will be used in colocalization studies with known cellular markers. [SM3.1]This work establishes a system to experimentally validate the expression of accessory proteins in novel Peromyscus coronaviruses. Ultimately, we aim to evaluate the role of these proteins during infection. Thus far, we have successfully isolated one of the three viruses, Highland Creek Peromyscus coronavirus, and will perform infection studies using host and other mammalian cell lines.