1-β- d -Arabinofuranosylcytosine Inhibits Borna Disease Virus Replication and Spread

Abstract

Borna disease virus (BDV) is a nonsegmented, negative-strand RNA virus that causes neurological diseases in a variety of warm-blooded animal species. There is general consensus that BDV can also infect humans, being a possible zoonosis. Although the clinical consequences of human BDV infection are still controversial, experimental BDV infection is a well-described model for human neuropsychiatric diseases. To date, there is no effective treatment against BDV. In this paper, we demonstrate that the nucleoside analog 1-␤-D-arabinofuranosylcytosine (Ara-C), a known inhibitor of DNA polymerases, inhibits BDV replication. Ara-C treatment inhibited BDV RNA and protein synthesis and prevented BDV cell-to-cell spread in vitro. Replication of other negative-strand RNA viruses such as influenza virus or measles virus was not inhibited by Ara-C, underscoring the particularity of the replication machinery of BDV. Strikingly, Ara-C treatment induced nuclear retention of viral ribonucleoparticles. These findings could not be attributed to known effects of Ara-C on the host cell, suggesting that Ara-C directly inhibits the BDV polymerase. Finally, we show that Ara-C inhibits BDV replication in vivo in the brain of infected rats, preventing persistent infection of the central nervous system as well as the development of clinical disease. These findings open the way to the development of effective antiviral therapy against BDV.

Borna Disease Virus Glycoprotein Is Required for Viral Dissemination in Neurons

“…Since in vivo, BDV replicates and persists predominantly in neurons of the limbic system, we used primary cultures of rat hippocampal neurons. After in vitro infection with BDV-CRV, BDV efficiently replicated in cultured neurons, confirming previous observations (1). To selectively study the process of virus dissemination and to separate this process from the primary infection with BDV-CRV, we performed the initial infection with BDV-CRV at a low MOI (0.025 FFU/cell).…”

“…In vivo, BDV replicates and persists predominantly in neurons of the limbic system. Recently, it was shown in vitro that rat hippocampal neurons are highly susceptible to infection with cell-free BDV (1). In order to assess whether BDV-GP is required for neuronal dissemination of BDV, we used primary cultures of rat hippocampal neurons.…”

“…Primary hippocampal neurons were isolated from 1-day-old Sprague-Dawley rats (Janvier) (1). Briefly, the hippocampi were dissected and dissociated by mechanical trituration and digestion with phosphate-buffered saline (PBS) plus 0.3% Aspergillus protease (Sigma) for 10 min at room temperature.…”

Mechanism of the Antiviral Action of 1-β- d -Arabinofuranosylcytosine on Borna Disease Virus

“…It was surprising to find that it could inhibit BDV, a negative-stranded RNA virus that synthesizes only RNA. In addition, the effect against BDV could not be attributed to any known effect of Ara-C on the host cell (1). Therefore, we sought to elucidate the mechanism of action of Ara-C on BDV.…”

2′-Fluoro-2′-Deoxycytidine Inhibits Borna Disease Virus Replication and Spread

“…Previously, we showed that inhibition of BDV replication by Ara-C was associated with a nuclear retention of BDV antigens in infected cells (1). We took advantage of this characteristic to rapidly screen 2Ј-FdC and gemcitabine for their potential to inhibit BDV replication in Vero cells that were persistently infected with BDV (i.e., Vero-BV).…”