scholarly journals Selective Virus Resistance Conferred by Expression of Borna Disease Virus Nucleocapsid Components

2003 ◽  
Vol 77 (7) ◽  
pp. 4283-4290 ◽  
Author(s):  
Till Geib ◽  
Christian Sauder ◽  
Sascha Venturelli ◽  
Christel Hässler ◽  
Peter Staeheli ◽  
...  
Keyword(s):  
Disease Virus ◽  
Viral Infections ◽  
Acquired Resistance ◽  
Vero Cells ◽  
Polymerase Activity ◽  
Host Cells ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Viral Nucleocapsid ◽  
Borna Disease

ABSTRACT Persistent viral infections can render host cells resistant to superinfection with closely related viruses by largely uncharacterized mechanisms. We present evidence for superinfection exclusion in brains of Borna disease virus (BDV)-infected rats and in persistently infected Vero cells, and we suggest that acquired resistance to BDV is due to unbalanced intracellular levels of viral nucleocapsid components. We observed that expression of BDV protein P, N, or X rendered human cells resistant to subsequent challenge with BDV but not with other RNA viruses, indicating that incorrect stoichiometry of nucleocapsid components selectively blocked the polymerase activity of incoming viruses. Vero cells containing high levels of an untranslatable BDV-N transcript remained virus susceptible, demonstrating that viral protein rather than RNA mediated resistance. Transient overexpression of BDV-P in persistently infected Vero cells was also remarkably effective against BDV, indicating that the intracellular balance of viral nucleocapsid components could serve as a target for future therapeutic antiviral strategies.

scholarly journals The X Protein of Borna Disease Virus Serves Essential Functions in the Viral Multiplication Cycle

2007 ◽  
Vol 81 (13) ◽  
pp. 7297-7299 ◽  
Author(s):  
Marion Poenisch ◽  
Sandra Wille ◽  
Andreas Ackermann ◽  
Peter Staeheli ◽  
Urs Schneider
Keyword(s):  
Disease Virus ◽  
Gene Cassette ◽  
Vero Cells ◽  
Polymerase Activity ◽  
Virus Multiplication ◽  
Borna Disease Virus ◽  
Multiplication Cycle ◽  
X Gene ◽  
A Site ◽  
Borna Disease

ABSTRACT The X gene of Borna disease virus (BDV) encodes a nonstructural 10-kDa protein that can interact with viral polymerase cofactor P, thus regulating polymerase activity. It remained unknown whether X is essential for virus multiplication. All our attempts to generate mutant BDV with a nonfunctional X gene proved unsuccessful. However, a mutant virus with an inactive X gene was able to replicate in Vero cells if an artificial gene cassette encoding X was inserted at a site near the 5′ end of the viral genome. These results indicate that X performs essential viral functions.

scholarly journals Virus-like particles in MDCK cells persistently infected with Borna disease virus

1994 ◽  
Vol 33 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Richard W. Compans ◽  
Lawrence R. Melsen ◽  
Juan Carlos de la Torre
Keyword(s):  
Disease Virus ◽  
Mdck Cells ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Virus Like Particles ◽  
Borna Disease

scholarly journals Downregulation of an Astrocyte-Derived Inflammatory Protein, S100B, Reduces Vascular Inflammatory Responses in Brains Persistently Infected with Borna Disease Virus

2007 ◽  
Vol 81 (11) ◽  
pp. 5940-5948 ◽  
Author(s):  
Naohiro Ohtaki ◽  
Wataru Kamitani ◽  
Yohei Watanabe ◽  
Yohei Hayashi ◽  
Hideyuki Yanai ◽  
...  
Keyword(s):  
Disease Virus ◽  
Persistent Infection ◽  
Immune Modulation ◽  
Inflammatory Responses ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Inflammatory Protein ◽  
Inflammatory Stimuli ◽  
Protein Immunoreactivity ◽  
Borna Disease

ABSTRACTBorna disease virus (BDV) is a neurotropic virus that causes a persistent infection in the central nervous system (CNS) of many vertebrate species. Although a severe reactive gliosis is observed in experimentally BDV-infected rat brains, little is known about the glial reactions contributing to the viral persistence and immune modulation in the CNS. In this regard, we examined the expression of an astrocyte-derived factor, S100B, in the brains of Lewis rats persistently infected with BDV. S100B is a Ca2+-binding protein produced mainly by astrocytes. A prominent role of this protein appears to be the promotion of vascular inflammatory responses through interaction with the receptor for advanced glycation end products (RAGE). Here we show that the expression of S100B is significantly reduced in BDV-infected brains despite severe astrocytosis with increased glial fibrillary acidic protein immunoreactivity. Interestingly, no upregulation of the expression of S100B, or RAGE, was observed in the persistently infected brains even when incited with several inflammatory stimuli, including lipopolysaccharide. In addition, expression of the vascular cell adhesion molecule 1 (VCAM-1), as well as the infiltration of encephalitogenic T cells, was significantly reduced in persistently infected brains in which an experimental autoimmune encephalomyelitis was induced by immunization with myelin-basic protein. Furthermore, we demonstrated that the continuous activation of S100B in the brain may be necessary for the progression of vascular immune responses in neonatally infected rat brains. Our results suggested that BDV infection may impair astrocyte functions via a downregulation of S100B expression, leading to the maintenance of a persistent infection.

scholarly journals Rat Model of Borna Disease Virus Transmission: Epidemiological Implications

2003 ◽  
Vol 77 (23) ◽  
pp. 12886-12890 ◽  
Author(s):  
Christian Sauder ◽  
Peter Staeheli
Keyword(s):  
Disease Virus ◽  
Rat Model ◽  
Infectious Virus ◽  
Virus Transmission ◽  
Farm Animals ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Rapid Transmission ◽  
Fresh Urine ◽  
Borna Disease

ABSTRACT Rapid transmission of Borna disease virus occurred upon cohabitation of persistently infected and naive rats. Infectious virus, which was abundantly present in fresh urine samples of carrier rats, entered the brains of recipient rats via the olfactory route. Thus, susceptible farm animals possibly acquire the virus from persistently infected rats.

scholarly journals Fine Structure and Morphogenesis of Borna Disease Virus

1999 ◽  
Vol 73 (1) ◽  
pp. 760-766 ◽  
Author(s):  
Takehiro Kohno ◽  
Toshiyuki Goto ◽  
Tomohiko Takasaki ◽  
Chizuko Morita ◽  
Takaaki Nakaya ◽  
...  
Keyword(s):  
Fine Structure ◽  
Cell Surface ◽  
Disease Virus ◽  
Mdck Cells ◽  
Rna Virus ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Virus Like Particles ◽  
Hemagglutinating Virus ◽  
Borna Disease

ABSTRACT Borna disease virus (BDV), a negative nonsegmented single-stranded RNA virus, has not been fully characterized morphologically. Here we present what is to our knowledge the first data on the fine ultrastructure and morphogenesis of BDV. The supernatant of MDCK cells persistently infected with BDV treated with n-butyrate contained many virus-like particles and more BDV-specific RNA than that of untreated samples. The particles were spherical, enveloped, and approximately 130 nm in diameter; had spikes 7 nm in length; and reacted with BDV p40 antibody. A thin nucleocapsid, 4 nm in width, was present peripherally in contrast to the thick nucleocapsid of hemagglutinating virus of Japan. The BDV particles reproduced by budding on the cell surface.

scholarly journals Mechanism of Borna Disease Virus Entry into Cells

1998 ◽  
Vol 72 (1) ◽  
pp. 783-788 ◽  
Author(s):  
Daniel Gonzalez-Dunia ◽  
Beatrice Cubitt ◽  
Juan Carlos de la Torre
Keyword(s):  
Disease Virus ◽  
Virus Entry ◽  
Host Cells ◽  
Cell Surface Receptor ◽  
Animal Cells ◽  
Borna Disease Virus ◽  
C Terminus ◽  
Surface Receptor ◽  
Infected Cells ◽  
Borna Disease

ABSTRACT We have investigated the entry pathway of Borna disease virus (BDV). Virus entry was assessed by detecting early viral replication and transcription. Lysosomotropic agents (ammonium chloride, chloroquine, and amantadine), as well as energy depletion, prevented BDV infection, indicating that BDV enters host cells by endocytosis and requires an acidic intracellular compartment to allow membrane fusion and initiate infection. Consistent with this hypothesis, we observed that BDV-infected cells form extensive syncytia upon low-pH treatment. Entry of enveloped viruses into animal cells usually requires the membrane-fusing activity of viral surface glycoproteins (GPs). BDV GP is expressed as two products of 84 and 43 kDa (GP-84 and GP-43, respectively). We show here that only GP-43 is present at the surface of BDV-infected cells and therefore is likely the viral polypeptide responsible for triggering fusion events. We also present evidence that GP-43, which corresponds to the C terminus of GP-84, is generated by cleavage of GP-84 by the cellular protease furin. Hence, we propose that BDV GP-84 is involved in attachment to the cell surface receptor whereas its furin-cleaved product, GP-43, is involved in pH-dependent fusion after internalization of the virion by endocytosis.

The Borna disease virus (BoDV) 2 nucleoprotein is a conspecific protein that enhances BoDV-1 RNA-dependent RNA polymerase activity

2021 ◽  
Author(s):  
Takehiro Kanda ◽  
Masayuki Horie ◽  
Yumiko Komatsu ◽  
Keizo Tomonaga
Keyword(s):  
Disease Virus ◽  
Reverse Genetics ◽  
Rna Virus ◽  
Polymerase Activity ◽  
Wild Type ◽  
Borna Disease Virus ◽  
Rna Polymerase Activity ◽  
Nucleoprotein N ◽  
Transcription And Replication ◽  
Borna Disease

An RNA virus-based episomal vector (REVec) based on Borna disease virus 1 (BoDV-1) is a promising viral vector that achieves stable and long-term gene expression in transduced cells. However, the onerous procedure of reverse genetics used to generate a REVec is one of the challenges that must be overcome to make REVec technologies practical for use. In this study, to resolve the problems posed by reverse genetics, we focused on BoDV-2, a conspecific virus of BoDV-1 in the Mammalian 1 orthobornavirus . We synthesized the BoDV-2 nucleoprotein (N) and phosphoprotein (P) according to the reference sequences and evaluated their effects on the RNA polymerase activity of the BoDV-1 large protein (L) and viral replication. In the minireplicon assay, we found that BoDV-2 N significantly enhanced BoDV-1 polymerase activity and that BoDV-2 P supported further enhancement of this activity by N. A single amino acid substitution assay identified serine at position 30 of BoDV-2 N and alanine at position 24 of BoDV-2 P as critical amino acid residues for the enhancement of BoDV-1 polymerase activity. In reverse genetics, on the other hand, BoDV-2 N alone was sufficient to increase the rescue efficiency of the REVec. We showed that the REVec can be rescued directly from transfected 293T cells by using BoDV-2 N as a helper plasmid without cocultivation with Vero cells and following several weeks of passage. In addition, a chimeric REVec harboring the BoDV-2 N produced much higher levels of transgene mRNA and genomic RNA than the wild-type REVec in transduced cells. Our results contribute to not only improvements to the REVec system but also understanding of the molecular regulation of orthobornavirus polymerase activity. Importance Borna disease virus 1 (BoDV-1), a prototype virus of the species Mammalian 1 orthobornavirus , is a nonsegmented negative-strand RNA virus that persists in the host nucleus. The nucleoprotein (N) of BoDV-1 encapsidates genomic and antigenomic viral RNA, playing important roles in viral transcription and replication. In this study, we demonstrated that the N of BoDV-2, another genotype in the species Mammalian 1 orthobornavirus , can participate in the viral ribonucleoprotein complex of BoDV-1 and enhance the activity of BoDV-1 polymerase (L) in both the BoDV-1 minireplicon assay and reverse genetics system. Chimeric recombinant BoDV-1 expressing BoDV-2 N but not BoDV-1 N showed higher transcription and replication levels, whereas the propagation and infectious particle production of the chimeric virus were comparable to those of wild-type BoDV-1, suggesting that the level of viral replication in the nucleus is not directly involved in the progeny virion production of BoDVs. Our results demonstrate a molecular mechanism of bornaviral polymerase activity, which will contribute to further development of vector systems using orthobornaviruses.

scholarly journals Alpha/Beta Interferon Promotes Transcription and Inhibits Replication of Borna Disease Virus in Persistently Infected Cells

2001 ◽  
Vol 75 (17) ◽  
pp. 8216-8223 ◽  
Author(s):  
Peter Staeheli ◽  
Maria Sentandreu ◽  
Axel Pagenstecher ◽  
Jürgen Hausmann
Keyword(s):  
Disease Virus ◽  
Cultured Cells ◽  
Genome Replication ◽  
Wild Type ◽  
Endogenous Virus ◽  
Viral Mrnas ◽  
Borna Disease Virus ◽  
Persistently Infected ◽  
Alpha Beta ◽  
Borna Disease

ABSTRACT Borna disease virus (BDV) is a noncytolytic RNA virus that can replicate in the central nervous system (CNS) of mice. This study shows that BDV multiplication was efficiently blocked in transgenic mice that express mouse alpha-1 interferon (IFN-α1) in astrocytes. To investigate whether endogenous virus-induced IFN might similarly restrict BDV, we usedIFNAR 0/0 mice, which lack a functional alpha/beta IFN (IFN-α/β) receptor. As would be expected if virus-induced IFN were important to control BDV infection, we found that cultured embryo cells of IFNAR 0/0 mice supported viral multiplication, whereas cells from wild-type mice did not. Unexpectedly, however, BDV spread through the CNSs ofIFNAR 0/0 and wild-type mice with similar kinetics, suggesting that activation of endogenous IFN-α/β genes in BDV-infected brains was too weak or occurred too late to be effective. Surprisingly, Northern blot analysis showed that the levels of the most abundant viral mRNAs in the brains of persistently infectedIFNAR 0/0 mice were about 20-fold lower than those in wild-type mice. In contrast, genomic viral RNA was produced in about a 10-fold excess in the brains ofIFNAR 0/0 mice. Human IFN-α2 similarly enhanced transcription and simultaneously repressed replication of the BDV genome in persistently infected Vero cells. Thus, in persistently infected neurons and cultured cells, IFN-α/β appears to freeze the BDV polymerase in the transcriptional mode, resulting in enhanced viral mRNA synthesis and suppressing viral genome replication.

scholarly journals Active Borna Disease Virus Polymerase Complex Requires a Distinct Nucleoprotein-to-Phosphoprotein Ratio but No Viral X Protein

2003 ◽  
Vol 77 (21) ◽  
pp. 11781-11789 ◽  
Author(s):  
Urs Schneider ◽  
Melanie Naegele ◽  
Peter Staeheli ◽  
Martin Schwemmle
Keyword(s):  
Disease Virus ◽  
Vero Cells ◽  
Expression Vectors ◽  
Regulatory Function ◽  
Functional Assay ◽  
X Protein ◽  
Borna Disease Virus ◽  
N Protein ◽  
Polymerase Complex ◽  
Borna Disease

ABSTRACT Analysis of the composition and regulation of the Borna disease virus (BDV) polymerase complex has so far been limited by the lack of a functional assay. To establish such an assay on the basis of an artificial minigenome, we constructed expression vectors encoding either nucleoprotein (N), phosphoprotein (P), X protein, or polymerase (L) of BDV under the control of the chicken β-actin promoter. A Flag-tagged version of L colocalized with virus-encoded N and P in characteristic nuclear dots of BDV-infected cells and increased viral N-protein levels in persistently infected Vero cells. Vector-driven expression of L, N, and P in BSR-T7 cells together with a negative-sense BDV minigenome carrying a chloramphenicol acetyltransferase (CAT) reporter gene resulted in efficient synthesis of CAT protein. Induction of CAT protein synthesis strongly depended on a 10- to 30-fold molar excess of the N-encoding plasmid over the P-encoding plasmid. Cotransfection of even small amounts of plasmid encoding the viral X protein reduced CAT synthesis to background levels. Thus, the N-to-P stoichiometry seems to play a central role in the regulation of the BDV polymerase complex. Our data further suggest a negative regulatory function for the X protein of BDV.

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