The X proteins of bornaviruses interfere with type I interferon signalling

Jonas Johansson Wensman, Muhammad Munir, Srinivas Thaduri, Katarina Hörnaeus, Muhammad Rizwan, Anne-Lie Blomström, Thomas Briese, W. Ian Lipkin, Mikael Berg

¹Swedish University of Agricultural Sciences, Department of Biomedical Sciences and Veterinary Public Health, Section of Virology, PO Box 7028, SE-750 07 Uppsala, Sweden

²Swedish University of Agricultural Sciences, Department of Clinical Sciences, Division of Ruminant Medicine and Veterinary Epidemiology, PO Box 7054, SE-750 07 Uppsala, Sweden

³Columbia University, Mailman School of Public Health, Center for Infection and Immunity, 722 West 168th Street, 10032 New York, NY, USA

Correspondence
Jonas Johansson Wensman Jonas.Wensman{at}slu.se

Abstract

Borna disease virus (BDV) is a neurotropic, negative-stranded RNA virus causing persistent infection and progressive neurological disorders in a wide range of warm-blooded animals. The role of the small non-structural X protein in viral pathogenesis is not completely understood. Here we investigated whether the X protein of BDV and avian bornavirus (ABV) interferes with the type I interferon (IFN) system, similar to other non-structural proteins of negative-stranded RNA viruses. In luciferase reporter assays, we found that the X protein of various bornaviruses interfered with the type I IFN system at all checkpoints investigated, in contrast to previously reported findings, resulting in reduced type I IFN secretion.