title: Intracerebral Borna disease virus infection of bank voles leading to peripheral spread and reverse transcription of viral RNA.
abstract: Bornaviruses, which chronically infect many species, can cause severe neurological diseases in some animal species; their association with human neuropsychiatric disorders is, however, debatable. The epidemiology of Borna disease virus (BDV), as for other members of the family Bornaviridae, is largely unknown, although evidence exists for a reservoir in small mammals, for example bank voles (Myodes glareolus). In addition to the current exogenous infections and despite the fact that bornaviruses have an RNA genome, bornavirus sequences integrated into the genomes of several vertebrates millions of years ago. Our hypothesis is that the bank vole, a common wild rodent species in traditional BDV-endemic areas, can serve as a viral host; we therefore explored whether this species can be infected with BDV, and if so, how the virus spreads and whether viral RNA is transcribed into DNA in vivo.We infected neonate bank voles intracerebrally with BDV and euthanized them 2 to 8 weeks post-infection. Specific Ig antibodies were detectable in 41%. Histological evaluation revealed no significant pathological alterations, but BDV RNA and antigen were detectable in all infected brains. Immunohistology demonstrated centrifugal spread throughout the nervous tissue, because viral antigen was widespread in peripheral nerves and ganglia, including the mediastinum, esophagus, and urinary bladder. This was associated with viral shedding in feces, of which 54% were BDV RNA-positive, and urine at 17%. BDV nucleocapsid gene DNA occurred in 66% of the infected voles, and, surprisingly, occasionally also phosphoprotein DNA. Thus, intracerebral BDV infection of bank vole led to systemic infection of the nervous tissue and viral excretion, as well as frequent reverse transcription of the BDV genome, enabling genomic integration. This first experimental bornavirus infection in wild mammals confirms the recent findings regarding bornavirus DNA, and suggests that bank voles are capable of bornavirus transmission.
authors.affiliation: Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland. Paula.Kinnunen@helsinki.fi
authors.forename: Paula Maria
authors.initials: PM
authors.lastname: Kinnunen
authors.forename: Hanna
authors.initials: H
authors.lastname: Inkeroinen
authors.forename: Mette
authors.initials: M
authors.lastname: Ilander
authors.forename: Eva Riikka
authors.initials: ER
authors.lastname: Kallio
authors.forename: Henna Pauliina
authors.initials: HP
authors.lastname: Heikkilä
authors.forename: Esa
authors.initials: E
authors.lastname: Koskela
authors.forename: Tapio
authors.initials: T
authors.lastname: Mappes
authors.forename: Airi
authors.initials: A
authors.lastname: Palva
authors.forename: Antti
authors.initials: A
authors.lastname: Vaheri
authors.forename: Anja
authors.initials: A
authors.lastname: Kipar
authors.forename: Olli
authors.initials: O
authors.lastname: Vapalahti
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000917:Antibody Formation / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D003411:Arvicolinae / Q000276:immunology / Q000821:virology*; D001890:Borna Disease / Q000276:immunology / Q000652:urine / Q000821:virology*; D001891:Borna disease virus / Q000276:immunology / Q000502:physiology*; D001921:Brain / Q000473:pathology / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics; D004197:Disease Reservoirs; D005243:Feces / Q000821:virology; D006801:Humans; D017933:Peripheral Nervous System / Q000473:pathology / Q000821:virology*; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics*; D015203:Reproducibility of Results; D048348:Reverse Transcription / Q000235:genetics*; D001743:Urinary Bladder / Q000473:pathology / Q000821:virology; D014556:Urine / Q000821:virology; D014779:Virus Replication / Q000502:physiology
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral; D012367:RNA, Viral