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Zhang LN, Huang YH, Liu H, Li LX, Bai X, Yang GD. Molecular detection of bornavirus in parrots imported to China in 2022. BMC Vet Res 2023; 19:259. [PMID: 38057808 DOI: 10.1186/s12917-023-03825-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023] Open
Abstract
BACKGROUND Avian bornavirus (ABV) is a neurotropic virus, it has been established as the primary causative agent of proventricular dilatation disease (PDD). However, substantial international trade and transnational trafficking of wild birds occur, potentially enabling these birds to harbor and transmit pathogens to domestic poultry, adversely affecting their well-being. Real-time RT-PCR was employed to detect the presence of PaBV-4 in parrots imported to China in 2022. RESULTS In 2022, a total of 47 cloacal swabs from 9 distinct species of parrots were collected at the Wildlife Rescue Monitoring Center in Guangdong, China. The purpose of this collection was to detect the presence of PaBV-4. Using real-time PCR techniques, it was determined that the positive rate of PaBV-4 was 2.12% (1 out of 47) in parrots. The PaBV-4 virus was detected in a Amazona aestiva that had been adopted for one month. Conversely, all other species tested negative for the virus. Subsequently, the whole genome of the PaBV-4 GD2207 strains was sequenced, and the homology and genetic evolution between these strains and previously published PaBV-4 strains on GenBank were analyzed using DNAStar and MEGA7.0 software. The findings revealed that the full-length genome of PaBV-4 consisted of 8915 nucleotides and encoded six proteins. Additionally, it exhibited the highest nucleotide similarity (99.9%) to the GZ2019 strain, which causes death and severe clinical symptoms in Aratinga solstitialis. Furthermore, when compared to other strains of PaBV-4, the GD2207 strain demonstrated the highest amino acid homology with GZ2019. The phylogenetic analysis demonstrated that the GD2207 strain clustered with various strains found in Japanese, American, and German parrots, indicating a close genetic relationship with PaBV-4, but it revealed a distant relationship with PaBV-5 Cockg5 from America. Notably, the GD2207 was closely associated with the GZ2019 strain from Aratinga solstitialis in China. CONCLUSION This study presents the preliminary identification of PaBV-4 in Amazona aestiva parrots, emphasizing its importance as the predominant viral genotype linked to parrot infections resulting from trade into China. Through genetic evolution analysis, it was determined that the GD2207 strain of PaBV-4 exhibits the closest genetic relationship with GZ 2019 (Aratinga solstitialis, China), M14 (Ara macao, USA), AG5 (Psittacus erithacus, USA) and 6758 (Ara ararauna, Germany) suggesting a shared ancestry.
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Affiliation(s)
- Li-Na Zhang
- Eco-Engineering Department, Guangdong, Eco-Engineering Polytechnic, Guangzhou, Guangdong Province, China
| | - Yu-Han Huang
- School of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China
| | - Hao Liu
- School of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China
| | - Li-Xia Li
- School of Life Sciences and Engineering, Foshan University, Foshan, Guangdong Province, China
| | - Xue Bai
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin Province, China
| | - Guang-Da Yang
- Guangdong Wildlife Rescue Monitoring Center, Guangdong Academy of Forestry, Guangzhou, Guangdong Province, China.
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Teng D, Ueda K, Honda T. Impact of Borna Disease Virus Infection on the Transcriptome of Differentiated Neuronal Cells and Its Modulation by Antiviral Treatment. Viruses 2023; 15:v15040942. [PMID: 37112922 PMCID: PMC10145824 DOI: 10.3390/v15040942] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/04/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Borna disease virus (BoDV-1) is a highly neurotropic RNA virus that causes neurobehavioral disturbances such as abnormal social activities and memory impairment. Although impairments in the neural circuits caused by BoDV-1 infection induce these disturbances, the molecular basis remains unclear. Furthermore, it is unknown whether anti-BoDV-1 treatments can attenuate BoDV-1-mediated transcriptomic changes in neuronal cells. In this study, we investigated the effects of BoDV-1 infection on neuronal differentiation and the transcriptome of differentiated neuronal cells using persistently BoDV-1-infected cells. Although BoDV-1 infection did not have a detectable effect on intracellular neuronal differentiation processes, differentiated neuronal cells exhibited transcriptomic changes in differentiation-related genes. Some of these transcriptomic changes, such as the decrease in the expression of apoptosis-related genes, were recovered by anti-BoDV-1 treatment, while alterations in the expression of other genes remained after treatment. We further demonstrated that a decrease in cell viability induced by differentiation processes in BoDV-1-infected cells can be relieved with anti-BoDV-1 treatment. This study provides fundamental information regarding transcriptomic changes after BoDV-1 infection and the treatment in neuronal cells.
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Grants
- JP18H02664 Ministry of Education, Culture, Sports, Science and Technology
- JP18K19449 Ministry of Education, Culture, Sports, Science and Technology
- JP21H02738 Ministry of Education, Culture, Sports, Science and Technology
- JP22K19436 Ministry of Education, Culture, Sports, Science and Technology
- none Takeda Science Foundation
- none Kobayashi International Scholarship Foundation
- none Naito Foundation
- none Suzuken Memorial Foundation
- none SEI Group CSR Foundation
- none Ryobi Teien Memory Foundation
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Affiliation(s)
- Da Teng
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | - Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
- Department of Virology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan
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3
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Kaneko Y, Naito Y, Koide R, Parrish NF, Takahashi T. The regulation of persistent Borna disease virus infection by RNA silencing factors in human cells. Biochem Biophys Res Commun 2023; 658:122-127. [PMID: 37030066 DOI: 10.1016/j.bbrc.2023.03.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 02/20/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Viral infection induces diverse cellular immune responses. Some viruses induce the production of antiviral cytokines, alterations of endogenous gene expression, and apoptosis; however, other viruses replicate without inducing such responses, enabling them to persistently infect cells. Infection by Borna disease virus type 1 (BoDV-1) can result in fatal immune-mediated encephalitis, including in humans, yet infection of cells in vitro is generally persistent. The regulatory mechanisms underlying this persistent infection remain unclear. Here, we show that an enhancer of RNA-silencing, TRBP, positively regulates BoDV RNA level in human cells. Knockdown of TRBP decreased BoDV RNA levels in persistently-infected cells, whereas overexpression of TRBP increased BoDV RNA levels. To investigate the mechanism underlying this phenomenon, we performed immunoprecipitation assays and found that TRBP interacts with BoDV RNA. Furthermore, we performed cell fractionation, which revealed that persistent infection with BoDV does not alter the localization of TRBP and other RNA silencing factors in cells. Our results showed the regulation of persistent BoDV infection by RNA-silencing factors in human cells.
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Dürrwald R, Kolodziejek J, Oh DY, Herzog S, Liebermann H, Osterrieder N, Nowotny N. Vaccination against Borna Disease: Overview, Vaccine Virus Characterization and Investigation of Live and Inactivated Vaccines. Viruses 2022; 14:v14122706. [PMID: 36560710 PMCID: PMC9788498 DOI: 10.3390/v14122706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
(1) Background: Vaccination of horses and sheep against Borna disease (BD) was common in endemic areas of Germany in the 20th century but was abandoned in the early 1990s. The recent occurrence of fatal cases of human encephalitis due to Borna disease virus 1 (BoDV-1) has rekindled the interest in vaccination. (2) Methods: The full genomes of the BD live vaccine viruses "Dessau" and "Giessen" were sequenced and analyzed for the first time. All vaccination experiments followed a proof-of-concept approach. Dose-titration infection experiments were performed in rabbits, based on both cell culture- and brain-derived viruses at various doses. Inactivated vaccines against BD were produced from concentrated cell culture supernatants and investigated in rabbits and horses. The BoDV-1 live vaccine "Dessau" was administered to horses and antibody profiles were determined. (3) Results: The BD live vaccine viruses "Dessau" and "Giessen" belong to clusters 3 and 4 of BoDV-1. Whereas the "Giessen" virus does not differ substantially from field viruses, the "Dessau" virus shows striking differences in the M gene and the N-terminal part of the G gene. Rabbits infected with high doses of cell-cultured virus developed neutralizing antibodies and were protected from disease, whereas rabbits infected with low doses of cell-cultured virus, or with brain-derived virus did not. Inactivated vaccines were administered to rabbits and horses, following pre-defined vaccination schemes consisting of three vaccine doses of either adjuvanted or nonadjuvanted inactivated virus. Their immunogenicity and protective efficacy were compared to the BD live vaccine "Dessau". Seventy per cent of horses vaccinated with the BD live vaccine "Dessau" developed neutralizing antibodies after vaccination. (4) Conclusion: Despite a complex evasion of immunological responses by bornaviruses, some vaccination approaches can protect against clinical disease. For optimal effectiveness, vaccines should be administered at high doses, following vaccination schemes consisting of three vaccine doses as basic immunization. Further investigations are necessary in order to investigate and improve protection against infection and to avoid side effects.
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Affiliation(s)
- Ralf Dürrwald
- Unit 17: Influenza and Other Viruses of the Respiratory Tract, Department of Infectious Diseases, Robert Koch Institute, Seestraße 10, 13353 Berlin, Germany
- Correspondence: ; Tel.: +49-30-18754-2456
| | - Jolanta Kolodziejek
- Institute of Virology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Djin-Ye Oh
- Unit 17: Influenza and Other Viruses of the Respiratory Tract, Department of Infectious Diseases, Robert Koch Institute, Seestraße 10, 13353 Berlin, Germany
| | - Sibylle Herzog
- Institute of Virology, Justus-Liebig-University Giessen, 35392 Giessen, Germany
| | - Heinrich Liebermann
- retd., former Institute of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | | | - Norbert Nowotny
- Institute of Virology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
- Department of Basic Medical Sciences, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai P.O. Box 505055, United Arab Emirates
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5
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Kanda T, Tomonaga K. Reverse Genetics and Artificial Replication Systems of Borna Disease Virus 1. Viruses 2022; 14:v14102236. [PMID: 36298790 PMCID: PMC9612284 DOI: 10.3390/v14102236] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/08/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022] Open
Abstract
Borna disease virus 1 (BoDV-1) is a neurotropic RNA virus belonging to the family Bornaviridae within the order Mononegavirales. Whereas BoDV-1 causes neurological and behavioral disorders, called Borna disease (BD), in a wide range of mammals, its virulence in humans has been debated for several decades. However, a series of case reports in recent years have established the nature of BoDV-1 as a zoonotic pathogen that causes fatal encephalitis in humans. Although many virological properties of BoDV-1 have been revealed to date, the mechanism by which it causes fatal encephalitis in humans remains unclear. In addition, there are no effective vaccines or antiviral drugs that can be used in clinical practice. A reverse genetics approach to generating replication-competent recombinant viruses from full-length cDNA clones is a powerful tool that can be used to not only understand viral properties but also to develop vaccines and antiviral drugs. The rescue of recombinant BoDV-1 (rBoDV-1) was first reported in 2005. However, due to the slow nature of the replication of this virus, the rescue of high-titer rBoDV-1 required several months, limiting the use of this system. This review summarizes the history of the reverse genetics and artificial replication systems for orthobornaviruses and explores the recent progress in efforts to rescue rBoDV-1.
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Affiliation(s)
- Takehiro Kanda
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
- Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
- Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- Laboratory of RNA Viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
- Correspondence:
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Rubbenstroth D. Avian Bornavirus Research—A Comprehensive Review. Viruses 2022; 14:v14071513. [PMID: 35891493 PMCID: PMC9321243 DOI: 10.3390/v14071513] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 02/01/2023] Open
Abstract
Avian bornaviruses constitute a genetically diverse group of at least 15 viruses belonging to the genus Orthobornavirus within the family Bornaviridae. After the discovery of the first avian bornaviruses in diseased psittacines in 2008, further viruses have been detected in passerines and aquatic birds. Parrot bornaviruses (PaBVs) possess the highest veterinary relevance amongst the avian bornaviruses as the causative agents of proventricular dilatation disease (PDD). PDD is a chronic and often fatal disease that may engulf a broad range of clinical presentations, typically including neurologic signs as well as impaired gastrointestinal motility, leading to proventricular dilatation. It occurs worldwide in captive psittacine populations and threatens private bird collections, zoological gardens and rehabilitation projects of endangered species. In contrast, only little is known about the pathogenic roles of passerine and waterbird bornaviruses. This comprehensive review summarizes the current knowledge on avian bornavirus infections, including their taxonomy, pathogenesis of associated diseases, epidemiology, diagnostic strategies and recent developments on prophylactic and therapeutic countermeasures.
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Affiliation(s)
- Dennis Rubbenstroth
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany
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7
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Kanda T, Sakai M, Makino A, Tomonaga K. Exogenous expression of both matrix protein and glycoprotein facilitates infectious viral particle production of Borna disease virus 1. J Gen Virol 2022; 103. [PMID: 35819821 DOI: 10.1099/jgv.0.001767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Borna disease virus 1 (BoDV-1) is a non-segmented, negative-strand RNA virus that is characterized by persistent infection in the nucleus and low production of progeny virions. This feature impedes not only the harvesting of infectious viral particles from infected cells but also the rescue of high titres of recombinant BoDV-1 (rBoDV-1) by reverse genetics. Here, we demonstrate that exogenous expression of both matrix protein (M) and glycoprotein (G), which are constituents of the viral lipid envelope, significantly facilitates the formation of infectious particles and propagation of BoDV-1 without affecting its viral RNA synthesis. Furthermore, simultaneous transfection of M and G expression plasmids with N, P and L helper plasmids by reverse genetics drastically enhances the rescue efficiency of rBoDV-1. On the other hand, we also show that overexpression of M induces obvious cytotoxicity similar to that of other Mononegaviruses. Together with our recent report showing that excess expression of G induces aberrant accumulation of immature G, a potential stimulator of the host innate immune response, it is conceivable that BoDV-1 may suppress excess expression of M and G to reduce the cytopathic effect, thereby leading to maintenance of persistent infection. Our results contribute not only to the establishment of an efficient method to recover high-titre BoDV-1 but also to understanding the unique mechanism of persistent BoDV-1 infection.
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Affiliation(s)
- Takehiro Kanda
- Laboratory of RNA viruses, Department of Virus Research, Institution for Life and Medical Sciences, Kyoto University, Kyoto, Japan.,Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Madoka Sakai
- Laboratory of RNA viruses, Department of Virus Research, Institution for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Akiko Makino
- Laboratory of RNA viruses, Department of Virus Research, Institution for Life and Medical Sciences, Kyoto University, Kyoto, Japan.,Laboratory of RNA viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Keizo Tomonaga
- Laboratory of RNA viruses, Department of Virus Research, Institution for Life and Medical Sciences, Kyoto University, Kyoto, Japan.,Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Laboratory of RNA viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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8
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Guo Y, Xu X, Tang T, Sun L, Zhang X, Shen X, Li D, Wang L, Zhao L, Xie P. miR-505 inhibits replication of Borna disease virus 1 via inhibition of HMGB1-mediated autophagy. J Gen Virol 2022; 103. [PMID: 35060474 DOI: 10.1099/jgv.0.001713] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Borna disease virus 1 (BoDV-1) is a highly neurotropic RNA virus which was recently demonstrated to cause deadly human encephalitis. Viruses can modulate microRNA expression, in turn modulating cellular immune responses and regulating viral replication. A previous study indicated that BoDV-1 infection down-regulated the expression of miR-505 in rats. However, the underlying mechanism of miR-505 during BoDV-1 infection remains unknown. In this study, we found that miR-505 can inhibit autophagy activation by down-regulating the expression of its target gene HMGB1, and ultimately inhibit the replication of BoDV-1. Specifically, we found that the expression of miR-505 was significantly down-regulated in rat primary neurons stably infected with BoDV-1. Overexpression of miR-505 can inhibit the replication of BoDV-1 in cells. Bioinformatics analysis and dual luciferase reporter gene detection confirmed that during BoDV-1 infection, the high-mobility group protein B1 (HMGB1) that mediates autophagy is the direct target gene of miR-505. The expression of HMGB1 was up-regulated after BoDV-1 infection, and overexpression of miR-505 could inhibit the expression of HMGB1. Autophagy-related detection found that after infection with BoDV-1, the expression of autophagy-related proteins and autophagy-related marker LC3 in neuronal cells was significantly up-regulated. Autophagy flow experiments and transmission electron microscopy also further confirmed that BoDV-1 infection activated HMGB1-mediated autophagy. Further regulating the expression of miR-505 found that overexpression of miR-505 significantly inhibited HMGB1-mediated autophagy. The discovery of this mechanism may provide new ideas and directions for the prevention and treatment of BoDV-1 infection in the future.
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Affiliation(s)
- Yujie Guo
- NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
- Department of Neurology, Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Xiaoyan Xu
- Department of Pathology, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Tian Tang
- Department of Laboratory Medicine, Jintang First People’s Hospital, West China Hospital Sichuan University JinTang Hospital, Chengdu, Sichuan, PR China
| | - Lin Sun
- Department of Anaesthesia and Pain, The First People’s Hospital of Chongqing Liangjiang New Area, Chongqing, PR China
| | - Xiong Zhang
- Department of Neurology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Xia Shen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
- NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Dan Li
- Department of Pathology, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
| | - Lixin Wang
- Department of Pathology, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
| | - Libo Zhao
- Department of Neurology, Yongchuan Hospital of Chongqing Medical University, Chongqing, PR China
| | - Peng Xie
- NHC Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
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The Borna Disease Virus 2 (BoDV-2) Nucleoprotein Is a Conspecific Protein That Enhances BoDV-1 RNA-Dependent RNA Polymerase Activity. J Virol 2021; 95:e0093621. [PMID: 34406860 DOI: 10.1128/jvi.00936-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
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 an 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, conversely, 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 to 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.
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Dolnik O, Gerresheim GK, Biedenkopf N. New Perspectives on the Biogenesis of Viral Inclusion Bodies in Negative-Sense RNA Virus Infections. Cells 2021; 10:cells10061460. [PMID: 34200781 PMCID: PMC8230417 DOI: 10.3390/cells10061460] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Infections by negative strand RNA viruses (NSVs) induce the formation of viral inclusion bodies (IBs) in the host cell that segregate viral as well as cellular proteins to enable efficient viral replication. The induction of those membrane-less viral compartments leads inevitably to structural remodeling of the cellular architecture. Recent studies suggested that viral IBs have properties of biomolecular condensates (or liquid organelles), as have previously been shown for other membrane-less cellular compartments like stress granules or P-bodies. Biomolecular condensates are highly dynamic structures formed by liquid-liquid phase separation (LLPS). Key drivers for LLPS in cells are multivalent protein:protein and protein:RNA interactions leading to specialized areas in the cell that recruit molecules with similar properties, while other non-similar molecules are excluded. These typical features of cellular biomolecular condensates are also a common characteristic in the biogenesis of viral inclusion bodies. Viral IBs are predominantly induced by the expression of the viral nucleoprotein (N, NP) and phosphoprotein (P); both are characterized by a special protein architecture containing multiple disordered regions and RNA-binding domains that contribute to different protein functions. P keeps N soluble after expression to allow a concerted binding of N to the viral RNA. This results in the encapsidation of the viral genome by N, while P acts additionally as a cofactor for the viral polymerase, enabling viral transcription and replication. Here, we will review the formation and function of those viral inclusion bodies upon infection with NSVs with respect to their nature as biomolecular condensates.
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Optimal Expression of the Envelope Glycoprotein of Orthobornaviruses Determines the Production of Mature Virus Particles. J Virol 2021; 95:JVI.02221-20. [PMID: 33268525 PMCID: PMC8092845 DOI: 10.1128/jvi.02221-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
An RNA virus-based episomal vector (REVec) whose backbone is Borna disease virus 1 (BoDV-1) can provide long-term gene expression in transduced cells. To improve the transduction efficiency of REVec, we evaluated the role of the viral envelope glycoprotein (G) of the genus Orthobornavirus, including that of BoDV-1, in the production of infectious particles. By using G-pseudotype assay in which the lack of G in G-deficient REVec (ΔG-REVec) was compensated for expression of G, we found that excess expression of BoDV-1-G does not affect particle production itself but results in uncleaved and aberrant mature G expression in the cells, leading to the production of REVec particles with low transduction titers. We revealed that the expression of uncleaved G in the cells inhibits the incorporation of mature G and vgRNA into the particles. This feature of G was conserved among mammalian and avian orthobornaviruses; however, the cleavage efficacy of canary bornavirus 1 (CnBV-1)-G was exceptionally not impaired by its excess expression, which led to the production of the pseudotype ΔG-REVec with the highest titer. Chimeric G proteins between CnBV-1 and -2 revealed that the signal peptide of CnBV-1-G was responsible for the cleavage efficacy through the interaction with intracellular furin. We showed that CnBV-1 G leads to the development of pseudotyped REVec with high transduction efficiency and a high-titer recombinant REVec. Our study demonstrated that the restricted expression of orthobornavirus G contributes to the regulation of infectious particle production, the mechanism of which can improve the transduction efficiency of REVec.IMPORTANCE Most viruses causing persistent infection produce few infectious particles from the infected cells. Borna disease virus 1, a member of the genus Orthobornavirus, is an RNA virus that persistently infects the nucleus and has been applied to vectors for long-term gene expression. In this study, we showed that, common among orthobornaviruses, excessive G expression does not affect particle production itself but reduces the production of infectious particles with mature G and genomic RNA. This result suggested that limited G expression contributes to suppressing abnormal viral particle production. On the other hand, we found that canary bornavirus 1 has an exceptional G maturation mechanism and produces a high-titer virus. Our study will contribute to not only understanding the mechanism of infectious particle production but also improving the vector system of orthobornaviruses.
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Komatsu Y, Tomonaga K. Reverse genetics approaches of Borna disease virus: applications in development of viral vectors and preventive vaccines. Curr Opin Virol 2020; 44:42-48. [PMID: 32659515 DOI: 10.1016/j.coviro.2020.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 01/10/2023]
Abstract
The plasmid-based reverse genetics system, which involves generation of recombinant viruses from cloned cDNA, has accelerated the understanding of clinical and virological aspects of different viruses. Borna disease virus (BoDV) is a nonsegmented, negative-strand RNA virus that causes persistent intranuclear infection in various vertebrate species. Since its first report, reverse genetics approaches with modified strategies have greatly improved rescue efficiency of recombinant BoDV and enhanced the understanding of function of each viral protein and mechanism of intranuclear persistency. Here, we summarize different reverse genetics approaches of BoDV and recent developments in the use of reverse genetics for generation of viral vectors for gene therapy and virus-like particles for potential preventive vaccines.
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Affiliation(s)
- Yumiko Komatsu
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (inFront), Kyoto University, Kyoto, Japan; Keihanshin Consortium for Fostering the Next Generation of Global Leaders in Research, Kyoto University, Kyoto, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (inFront), Kyoto University, Kyoto, Japan; Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan; Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
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ADAR2 Is Involved in Self and Nonself Recognition of Borna Disease Virus Genomic RNA in the Nucleus. J Virol 2020; 94:JVI.01513-19. [PMID: 31852792 DOI: 10.1128/jvi.01513-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/13/2019] [Indexed: 12/28/2022] Open
Abstract
Cells sense pathogen-derived double-stranded RNA (dsRNA) as nonself. To avoid autoimmune activation by self dsRNA, cells utilize A-to-I editing by adenosine deaminase acting on RNA 1 (ADAR1) to disrupt dsRNA structures. Considering that viruses have evolved to exploit host machinery, A-to-I editing could benefit innate immune evasion by viruses. Borna disease virus (BoDV), a nuclear-replicating RNA virus, may require escape from nonself RNA-sensing and immune responses to establish persistent infection in the nucleus; however, the strategy by which BoDV evades nonself recognition is unclear. Here, we evaluated the involvement of ADARs in BoDV infection. The infection efficiency of BoDV was markedly decreased in both ADAR1 and ADAR2 knockdown cells at the early phase of infection. Microarray analysis using ADAR2 knockdown cells revealed that ADAR2 reduces immune responses even in the absence of infection. Knockdown of ADAR2 but not ADAR1 significantly reduced the spread and titer of BoDV in infected cells. Furthermore, ADAR2 knockout decreased the infection efficiency of BoDV, and overexpression of ADAR2 rescued the reduced infectivity in ADAR2 knockdown cells. However, the growth of influenza A virus, which causes acute infection in the nucleus, was not affected by ADAR2 knockdown. Moreover, ADAR2 bound to BoDV genomic RNA and induced A-to-G mutations in the genomes of persistently infected cells. We finally demonstrated that BoDV produced in ADAR2 knockdown cells induces stronger innate immune responses than those produced in wild-type cells. Taken together, our results suggest that BoDV utilizes ADAR2 to edit its genome to appear as "self" RNA in order to maintain persistent infection in the nucleus.IMPORTANCE Cells use the editing activity of adenosine deaminase acting on RNA proteins (ADARs) to prevent autoimmune responses induced by self dsRNA, but viruses can exploit this process to their advantage. Borna disease virus (BoDV), a nuclear-replicating RNA virus, must escape nonself RNA sensing by the host to establish persistent infection in the nucleus. We evaluated whether BoDV utilizes ADARs to prevent innate immune induction. ADAR2 plays a key role throughout the BoDV life cycle. ADAR2 knockdown reduced A-to-I editing of BoDV genomic RNA, leading to the induction of a strong innate immune response. These data suggest that BoDV exploits ADAR2 to edit nonself genomic RNA to appear as self RNA for innate immune evasion and establishment of persistent infection.
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Pham PH, Leacy A, Deng L, Nagy É, Susta L. Isolation of Ontario aquatic bird bornavirus 1 and characterization of its replication in immortalized avian cell lines. Virol J 2020; 17:16. [PMID: 32005267 PMCID: PMC6995091 DOI: 10.1186/s12985-020-1286-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 01/20/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aquatic bird bornavirus 1 (ABBV-1) has been associated with neurological diseases in wild waterfowls. In Canada, presence of ABBV-1 was demonstrated by RT-qPCR and immunohistochemistry in tissues of waterfowls with history of neurological disease and inflammation of the central and peripheral nervous tissue, although causation has not been proven by pathogenesis experiments, yet. To date, in vitro characterization of ABBV-1 is limited to isolation in primary duck embryo fibroblasts. The objectives of this study were to describe isolation of ABBV-1 in primary duck embryonic fibroblasts (DEF), and characterize replication in DEF and three immortalized avian fibroblast cell lines (duck CCL-141, quail QT-35, chicken DF-1) in order to evaluate cellular permissivity and identify suitable cell lines for routine virus propagation. METHODS The virus was sequenced, and phylogenetic analysis performed on a segment of the N gene coding region. Virus spread in cell cultures, viral RNA and protein production, and titres were evaluated at different passages using immunofluorescence, RT-qPCR, western blotting, and tissue culture dose 50% (TCID50) assay, respectively. RESULTS The isolated ABBV-1 showed 97 and 99% identity to European ABBV-1 isolate AF-168 and North American ABBV-1 isolates 062-CQ and CG-N1489, and could infect and replicate in DEF, CCL-141, QT-35 and DF-1 cultures. Viral RNA was detected in all four cultures with highest levels observed in DEF and CCL-141, moderate in QT-35, and lowest in DF-1. N protein was detected in western blots from infected DEF, CCL-141 and QT-35 at moderate to high levels, but minimally in infected DF-1. Infectious titre was highest in DEF (between approximately 105 to 106 FFU / 106 cells). Regarding immortalized cell lines, CCL-141 showed the highest titre between approximately 104 to 105 FFU / 106 cells. DF-1 produced minimal infectious titre. CONCLUSIONS This study confirms the presence of ABBV-1 among waterfowl in Canada and reported additional in vitro characterization of this virus in different avian cell lines. ABBV-1 replicated to highest titre in DEF, followed by CCL-141 and QT-35, and poorly in DF-1. Our results showed that CCL-141 can be used instead of DEF for routine ABBV-1 production, if a lower titre is an acceptable trade-off for the simplicity of using immortalized cell line over primary culture.
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Affiliation(s)
- Phuc H Pham
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Alexander Leacy
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Li Deng
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Éva Nagy
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Leonardo Susta
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
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15
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Horie M. Interactions among eukaryotes, retrotransposons and riboviruses: endogenous riboviral elements in eukaryotic genomes. Genes Genet Syst 2020; 94:253-267. [PMID: 31257309 DOI: 10.1266/ggs.18-00049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Riboviruses are viruses that have RNA genomes and replicate only via RNA intermediates. Although they do not require a DNA phase for replication and do not encode reverse transcriptase, the presence of DNA forms of riboviral sequences in ribovirus-infected cells has been reported since the 1970s. Additionally, heritable ribovirus-derived sequences, called riboviral endogenous viral elements (EVEs), have been found in the genomes of many eukaryotes. These are now thought to be formed by the reverse transcription machineries of retrotransposons within eukaryotic genomes sometimes referred to as selfish elements. Surprisingly, some reverse-transcribed riboviral DNAs (including EVEs) provide physiological functions for their hosts, suggesting the occurrence of novel interactions among eukaryotic genomes, retrotransposons and riboviruses, and opening the door to new avenues of investigation. Here I review current knowledge on these triangular interactions, and discuss future directions in this field.
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Affiliation(s)
- Masayuki Horie
- Hakubi Center for Advanced Research, and Department of Virus Research, Institute for Frontier Life and Medical Sciences, Kyoto University
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16
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Teng D, Obika S, Ueda K, Honda T. A Small Interfering RNA Cocktail Targeting the Nucleoprotein and Large Protein Genes Suppresses Borna Disease Virus Infection. Front Microbiol 2019; 10:2781. [PMID: 31849913 PMCID: PMC6895540 DOI: 10.3389/fmicb.2019.02781] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022] Open
Abstract
Recently, Borna disease virus (BoDV-1)-related fatal encephalitis human cases have been reported, which highlights the potential of BoDV-1 to cause fatal human diseases. To protect the infected brain from lethal damage, it is critical to control BoDV-1 as quickly as possible. At present, antivirals against BoDV-1 are limited, and therefore, novel types of antivirals are needed. Here, we developed a novel treatment using small interfering RNAs (siRNAs) against BoDV-1. We screened several siRNAs targeting the viral N, M, and L genes for BoDV-1-reducing activity. Among the screened candidates, we chose two siRNAs that efficiently decreased the BoDV-1 load in persistently BoDV-1-infected cells to prepare a siRNA cocktail (TD-Borna) for BoDV-1 treatment. TD-Borna successfully reduced the BoDV-1 load without enhancing the risk of emergence of escape mutants. The combination of TD-Borna and T-705, a previously reported antiviral agent against bornaviruses, decreased the BoDV-1 load more efficiently than TD-Borna or T-705 alone. Furthermore, TD-Borna efficiently decreased the BoDV-1 load in BoDV-1-infected neuron-derived cells, in which T-705 did not decrease the viral load. Overall, we developed a novel antiviral candidate against BoDV-1, TD-Borna, that can be used in combination with T-705 and is effective against BoDV-1 in neuron-derived cells, in which T-705 is less effective. Considering that BoDV-1 is highly neurotropic, TD-Borna can offer a promising option to improve the outcome of BoDV-1 infection.
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Affiliation(s)
- Da Teng
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Shunsuke Obika
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Osaka, Japan
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17
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Intranasal Borna Disease Virus (BoDV-1) Infection: Insights into Initial Steps and Potential Contagiosity. Int J Mol Sci 2019; 20:ijms20061318. [PMID: 30875911 PMCID: PMC6470550 DOI: 10.3390/ijms20061318] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/10/2019] [Accepted: 03/10/2019] [Indexed: 12/11/2022] Open
Abstract
Mammalian Bornavirus (BoDV-1) typically causes a fatal neurologic disorder in horses and sheep, and was recently shown to cause fatal encephalitis in humans with and without transplant reception. It has been suggested that BoDV-1 enters the central nervous system (CNS) via the olfactory pathway. However, (I) susceptible cell types that replicate the virus for successful spread, and (II) the role of olfactory ensheathing cells (OECs), remained unclear. To address this, we studied the intranasal infection of adult rats with BoDV-1 in vivo and in vitro, using olfactory mucosal (OM) cell cultures and the cultures of purified OECs. Strikingly, in vitro and in vivo, viral antigen and mRNA were present from four days post infection (dpi) onwards in the olfactory receptor neurons (ORNs), but also in all other cell types of the OM, and constantly in the OECs. In contrast, in vivo, BoDV-1 genomic RNA was only detectable in adult and juvenile ORNs, nerve fibers, and in OECs from 7 dpi on. In vitro, the rate of infection of OECs was significantly higher than that of the OM cells, pointing to a crucial role of OECs for infection via the olfactory pathway. Thus, this study provides important insights into the transmission of neurotropic viral infections with a zoonotic potential.
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18
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Hirai Y, Domae E, Yoshikawa Y, Okamura H, Makino A, Tomonaga K. Intracellular dynamics of actin affects Borna disease virus replication in the nucleus. Virus Res 2019; 263:179-183. [PMID: 30769121 DOI: 10.1016/j.virusres.2019.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/09/2019] [Accepted: 02/11/2019] [Indexed: 01/21/2023]
Abstract
Borna disease virus (BoDV) is a nonsegmented, negative-strand RNA virus that uniquely replicates and establishes persistent infection in cell nucleus. Recent studies have demonstrated the presence of actin in the nucleus and its role in intranuclear phenomena such as transcription and DNA repair. Although nuclear actin is involved in the life cycle of some intranuclear DNA viruses, the interaction between BoDV and nuclear actin has not been reported. In this study, we show that the inhibition of the nucleocytoplasmic transport of actin affects the replication of BoDV in the nucleus. The knockdown of a nuclear export factor of actin, exportin 6, results in the induction of structural aberration in intranuclear viral factories of BoDV. Furthermore, the inhibition of the nuclear export of actin promotes accumulation of viral matrix protein in the cytoplasm and periphery of the infected cells. These results suggest that the dynamics of actin affect the replication of BoDV by disturbing the structure of viral factories in the nucleus.
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Affiliation(s)
- Yuya Hirai
- Department of Biology, Osaka Dental University, Hirakata, Osaka 573-1121, Japan
| | - Eisuke Domae
- Department of Biochemistry, Osaka Dental University, Hirakata, Osaka, 573-1121, Japan
| | - Yoshihiro Yoshikawa
- Department of Biochemistry, Osaka Dental University, Hirakata, Osaka, 573-1121, Japan
| | - Hideyuki Okamura
- Department of Biology, Osaka Dental University, Hirakata, Osaka 573-1121, Japan
| | - Akiko Makino
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (inFront), Kyoto University, Kyoto, 606-8507, Japan; Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8507, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (inFront), Kyoto University, Kyoto, 606-8507, Japan; Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8507, Japan; Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
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19
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de Araujo JL, Rodrigues-Hoffmann A, Giaretta PR, Guo J, Heatley J, Tizard I, Rech RR. Distribution of Viral Antigen and Inflammatory Lesions in the Central Nervous System of Cockatiels ( Nymphicus hollandicus) Experimentally Infected with Parrot Bornavirus 2. Vet Pathol 2018; 56:106-117. [PMID: 30235986 DOI: 10.1177/0300985818798112] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neurotropism is a striking characteristic of bornaviruses, including parrot bornavirus 2 (PaBV-2). Our study evaluated the distribution of inflammatory foci and viral nucleoprotein (N) antigen in the brain and spinal cord of 27 cockatiels ( Nymphicus hollandicus) following experimental infection with PaBV-2 by injection into the pectoral muscle. Tissue samples were taken at 12 timepoints between 5 and 114 days post-inoculation (dpi). Each experimental group had approximately 3 cockatiels per group and usually 1 negative control. Immunolabeling was first observed within the ventral horns of the thoracic spinal cord at 20 dpi and in the brain (thalamic nuclei and hindbrain) at 25 dpi. Both inflammation and viral antigen were restricted to the central core of the brain until 40 dpi. The virus then spread quickly at 60 dpi to both gray and white matter of all analyzed sections of the central nervous system (CNS). Encephalitis was most severe in the thalamus and hindbrain, while myelitis was most prominent in the gray matter and equally distributed in the cervical, thoracic, and lumbosacral spinal cord. Our results demonstrate a caudal to rostral spread of virus in the CNS following experimental inoculation of PABV-2 into the pectoral muscle, with the presence of viral antigen and inflammatory lesions first in the spinal cord and progressing to the brain.
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Affiliation(s)
- Jeann Leal de Araujo
- 1 Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | | | - Paula R Giaretta
- 1 Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Jianhua Guo
- 1 Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Jill Heatley
- 2 Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX, USA
| | - Ian Tizard
- 1 Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Raquel R Rech
- 1 Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
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20
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Mukai Y, Horie M, Tomonaga K. Systematic estimation of insertion dates of endogenous bornavirus-like elements in vesper bats. J Vet Med Sci 2018; 80:1356-1363. [PMID: 29973433 PMCID: PMC6115245 DOI: 10.1292/jvms.18-0211] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Endogenous bornavirus-like elements (EBLs) are sequences derived from bornaviruses (the
family Bornaviridae) that are integrated into animal genomes. They are
formed through germline insertions of segments of bornaviral transcripts into animal
genomes. Because EBLs are molecular fossils of bornaviruses, they serve as precious
sources of information to understand the evolutionary history of bornaviruses. Previous
studies revealed the presence of many EBLs in bat genomes, especially in vesper bats, and
suggested the long-term association between bats and bornaviruses. However, insertion
dates of EBLs are largely unknown because of the limitations of available bat genome
sequences in the public database. In this study, through a combination of database
searches, PCR, and sequencing approaches, we systematically determined the gene
orthologies of 13 lineages of EBLs in bats of the genus Myotis and
Eptesicus and family Vespertilionidae. Using the above data, we
estimated their insertion dates: the EBLs in vesper bats were inserted approximately 14.2
to 53 million years ago. These results suggest that vesper bats have been repeatedly
infected by bornaviruses at different points in time during evolution. This study provides
novel insights into the evolutionary history of bornaviruses and demonstrates the
robustness of combining database searches, PCR, and sequencing approaches to estimate
insertion dates of bornaviruses.
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Affiliation(s)
- Yahiro Mukai
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), Kyoto University, Kyoto 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Masayuki Horie
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), Kyoto University, Kyoto 606-8507, Japan.,Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8501, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), Kyoto University, Kyoto 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.,Department of Molecular Virology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
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21
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Fujino K, Yamamoto Y, Daito T, Makino A, Honda T, Tomonaga K. Generation of a non-transmissive Borna disease virus vector lacking both matrix and glycoprotein genes. Microbiol Immunol 2018; 61:380-386. [PMID: 28776750 DOI: 10.1111/1348-0421.12505] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/24/2017] [Accepted: 08/01/2017] [Indexed: 11/30/2022]
Abstract
Borna disease virus (BoDV), a prototype of mammalian bornavirus, is a non-segmented, negative strand RNA virus that often causes severe neurological disorders in infected animals, including horses and sheep. Unique among animal RNA viruses, BoDV transcribes and replicates non-cytopathically in the cell nucleus, leading to establishment of long-lasting persistent infection. This striking feature of BoDV indicates its potential as an RNA virus vector system. It has previously been demonstrated by our team that recombinant BoDV (rBoDV) lacking an envelope glycoprotein (G) gene develops persistent infections in transduced cells without loss of the viral genome. In this study, a novel non-transmissive rBoDV, rBoDV ΔMG, which lacks both matrix (M) and G genes in the genome, is reported. rBoDV-ΔMG expressing green fluorescence protein (GFP), rBoDV ΔMG-GFP, was efficiently generated in Vero/MG cells stably expressing both BoDV M and G proteins. Infection with rBoDV ΔMG-GFP was persistently maintained in the parent Vero cells without propagation within cell culture. The optimal ratio of M and G for efficient viral particle production by transient transfection of M and G expression plasmids into cells persistently infected with rBoDV ΔMG-GFP was also demonstrated. These findings indicate that the rBoDV ΔMG-based BoDV vector may provide an extremely safe virus vector system and could be a novel strategy for investigating the function of M and G proteins and the host range of bornaviruses.
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Affiliation(s)
- Kan Fujino
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan
| | - Yusuke Yamamoto
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Japan
| | - Takuji Daito
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan
| | - Akiko Makino
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan
| | - Tomoyuki Honda
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan
| | - Keizo Tomonaga
- Laboratory of RNA Viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Japan.,Department of Molecular Virology, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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22
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The Association Between Borna Disease Virus and Mood Disorders: A Systematic Review and Meta-Analysis. ARCHIVES OF NEUROSCIENCE 2018. [DOI: 10.5812/archneurosci.57779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Linkage between the leader sequence and leader RNA production in Borna disease virus-infected cells. Virology 2017; 510:104-110. [PMID: 28715652 DOI: 10.1016/j.virol.2017.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/20/2017] [Accepted: 07/07/2017] [Indexed: 12/11/2022]
Abstract
The 3'-untranslated region (UTR) of the non-segmented, negative-strand (NNS) RNA viral genome is called the leader sequence, and functions as the promoter for viral replication and transcription. NNS RNA viruses also use the sequence as a template to synthesize leader RNAs (leRNAs) with unknown functions. Borna disease virus (BDV) is unique because it establishes a persistent infection and replicates in the nucleus. No report has yet demonstrated the presence of leRNAs during BDV infection. Here, we report that BDV synthesizes leRNAs from the 3'-UTR of the genome. They started at position 5 in the 3'-UTR and ended by the transcription start signal of the nucleoprotein gene. The level of leRNA production is not correlated with the levels of viral replication and transcription. On the other hand, mutation of the 3'-UTR affects leRNA production. Our findings add a novel viral transcript to the BDV life cycle and shed light on BDV replication and/or transcription.
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Tokunaga T, Yamamoto Y, Sakai M, Tomonaga K, Honda T. Antiviral activity of favipiravir (T-705) against mammalian and avian bornaviruses. Antiviral Res 2017; 143:237-245. [DOI: 10.1016/j.antiviral.2017.04.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 01/18/2023]
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The biological significance of bornavirus-derived genes in mammals. Curr Opin Virol 2017; 25:1-6. [PMID: 28666136 DOI: 10.1016/j.coviro.2017.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/06/2017] [Accepted: 06/13/2017] [Indexed: 02/01/2023]
Abstract
The discoveries of sequences derived from non-retroviral viruses in eukaryotic genomes have significantly expanded our knowledge about virus evolution as well as the co-evolution between viruses and eukaryotes. However, the biological functions of such sequences in the host are largely unknown. Endogenous bornavirus-like elements (EBLs) have been relatively well studied by molecular biological methods, which have provided evidence that some EBLs have been co-opted by their hosts. This review highlights the current knowledge on the biological significance of EBLs, and discusses possible functions of EBLs. Further, we highlight the importance of extensive surveillance of exogenous viruses for a better understanding of endogenous viral sequences as well as the co-evolution of viruses and eukaryotes.
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26
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Randall RE, Griffin DE. Within host RNA virus persistence: mechanisms and consequences. Curr Opin Virol 2017; 23:35-42. [PMID: 28319790 PMCID: PMC5474179 DOI: 10.1016/j.coviro.2017.03.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/02/2017] [Indexed: 12/15/2022]
Abstract
In a prototypical response to an acute viral infection it would be expected that the adaptive immune response would eliminate all virally infected cells within a few weeks of infection. However many (non-retrovirus) RNA viruses can establish 'within host' persistent infections that occasionally lead to chronic or reactivated disease. Despite the importance of 'within host' persistent RNA virus infections, much has still to be learnt about the molecular mechanisms by which RNA viruses establish persistent infections, why innate and adaptive immune responses fail to rapidly clear these infections, and the epidemiological and potential disease consequences of such infections.
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Affiliation(s)
| | - Diane E Griffin
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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Abstract
AbstractBornaviruses cause neurologic diseases in several species of birds, especially parrots, waterfowl and finches. The characteristic lesions observed in these birds include encephalitis and gross dilatation of the anterior stomach — the proventriculus. The disease is thus known as proventricular dilatation disease (PDD). PDD is characterized by extreme proventricular dilatation, blockage of the passage of digesta and consequent death by starvation. There are few clinical resemblances between this and the bornaviral encephalitides observed in mammals. Nevertheless, there are common virus-induced pathogenic pathways shared across this disease spectrum that are explored in this review. Additionally, a review of the literature relating to gastroparesis in humans and the control of gastric mobility in mammals and birds points to several plausible mechanisms by which bornaviral infection may result in extreme proventricular dilatation.
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ANDO T, TAKINO T, MAKITA K, TAJIMA M, KOIWA M, HAGIWARA K. Sero-epidemiological analysis of vertical transmission relative risk of Borna disease virus infection in dairy herds. J Vet Med Sci 2016; 78:1669-1672. [PMID: 27498995 PMCID: PMC5138419 DOI: 10.1292/jvms.16-0156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/21/2016] [Indexed: 11/22/2022] Open
Abstract
Borna disease virus (BDV) is a virus that causes a neurological disease in domestic animals, including a variety of animal species in Japan. Few studies have examined the mode of transmission of this virus in cattle, and the exact mechanisms underlying the transmission of the virus need to be elucidated. This study aimed to examine the contribution of vertical transmission of the virus, which occurs when the virus is transmitted from the mother to offspring during gestation or birth. We used an epidemiological approach. The relative risk (RR) was calculated for cattle born to BDV sero-positive cows from farms with a higher within-herd prevalence of BDV (56.8%). We tested the sera of 1,122 dairy cattle from 24 dairy herds in Hokkaido Prefecture, Japan, for BDV infection using the ELISA and western blotting method. The overall level of BDV sero-prevalence was 22.1%. Seroprevalence was significantly higher in closed-breeding herds that do not have buying in cows (39.7%) than in farms that restock cattle by buying in cows (4.4%, P<0.01). The overall RR of BDV vertical transmission from infected mothers to their daughters was 1.86 (95% confidence interval (CI): 1.54-2.56). Our results show that vertical transmission contributes significantly to BDV transmission in the farms tested in this study.
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Affiliation(s)
- Tatsuya ANDO
- Ishikari Agricultural Mutual Relief Association, Hokkaido
067–0055, Japan
| | - Tadashi TAKINO
- School of Veterinary Medicine, Rakuno Gakuen University,
Ebetsu, Hokkaido 069–8501, Japan
- Scientific Feed Laboratory co., Ltd. 3–3 Miyahara-cho,
Takasaki-city, Gunma 370–1202, Japan
| | - Kohei MAKITA
- School of Veterinary Medicine, Rakuno Gakuen University,
Ebetsu, Hokkaido 069–8501, Japan
| | - Motoshi TAJIMA
- School of Veterinary Medicine, Rakuno Gakuen University,
Ebetsu, Hokkaido 069–8501, Japan
| | - Masateru KOIWA
- School of Veterinary Medicine, Rakuno Gakuen University,
Ebetsu, Hokkaido 069–8501, Japan
| | - Katsuro HAGIWARA
- School of Veterinary Medicine, Rakuno Gakuen University,
Ebetsu, Hokkaido 069–8501, Japan
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Hirai Y, Hirano Y, Matsuda A, Hiraoka Y, Honda T, Tomonaga K. Borna Disease Virus Assembles Porous Cage-like Viral Factories in the Nucleus. J Biol Chem 2016; 291:25789-25798. [PMID: 27803166 DOI: 10.1074/jbc.m116.746396] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/21/2016] [Indexed: 11/06/2022] Open
Abstract
Animal-derived RNA viruses frequently generate viral factories in infected cells. However, the details of how RNA viruses build such intracellular structures are poorly understood. In this study, we examined the structure and formation of the viral factories, called viral speckle of transcripts (vSPOTs), that are produced in the nuclei of host cells by Borna disease virus (BDV). Super-resolution microscopic analysis showed that BDV assembled vSPOTs as intranuclear cage-like structures with 59-180-nm pores. The viral nucleoprotein formed the exoskeletons of vSPOTs, whereas the other viral proteins appeared to be mainly localized within these structures. In addition, stochastic optical reconstruction microscopy revealed that filamentous structures resembling viral ribonucleoprotein complexes (RNPs) appeared to protrude from the outer surfaces of the vSPOTs. We also found that vSPOTs disintegrated into RNPs concurrently with the breakdown of the nuclear envelope during mitosis. These observations demonstrated that BDV generates viral replication factories whose shape and formation are regulated, suggesting the mechanism of the integrity of RNA virus persistent infection in the nucleus.
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Affiliation(s)
- Yuya Hirai
- From the Department of Biology, Osaka Dental University, Hirakata 573-1121.,the Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT)
| | - Yasuhiro Hirano
- the Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, and
| | - Atsushi Matsuda
- the Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, and.,the Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yasushi Hiraoka
- the Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, and.,the Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Tomoyuki Honda
- the Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT)
| | - Keizo Tomonaga
- the Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), .,Departments of Molecular Virology, Graduate School of Medicine, and.,Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507
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Kobayashi Y, Horie M, Nakano A, Murata K, Itou T, Suzuki Y. Exaptation of Bornavirus-Like Nucleoprotein Elements in Afrotherians. PLoS Pathog 2016; 12:e1005785. [PMID: 27518265 PMCID: PMC4982594 DOI: 10.1371/journal.ppat.1005785] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 07/01/2016] [Indexed: 11/18/2022] Open
Abstract
Endogenous bornavirus-like nucleoprotein elements (EBLNs), the nucleotide sequence elements derived from the nucleoprotein gene of ancient bornavirus-like viruses, have been identified in many animal genomes. Here we show evidence that EBLNs encode functional proteins in their host. Some afrotherian EBLNs were observed to have been maintained for more than 83.3 million years under negative selection. Splice variants were expressed from the genomic loci of EBLNs in elephant, and some were translated into proteins. The EBLN proteins appeared to be localized to the rough endoplasmic reticulum in African elephant cells, in contrast to the nuclear localization of bornavirus N. These observations suggest that afrotherian EBLNs have acquired a novel function in their host. Interestingly, genomic sequences of the first exon and its flanking regions in these EBLN loci were homologous to those of transmembrane protein 106B (TMEM106B). The upstream region of the first exon in the EBLN loci exhibited a promoter activity, suggesting that the ability of these EBLNs to be transcribed in the host cell was gained through capturing a partial duplicate of TMEM106B. In conclusion, our results strongly support for exaptation of EBLNs to encode host proteins in afrotherians. Endogenous retroviruses are representative of endogenous viral elements (EVEs), which are known to have occasionally served as the source of evolutionary innovations of the host. Endogenous bornavirus-like nucleoprotein element (EBLN) was the first EVE identified in mammalian genomes to have been derived from a non-retroviral RNA virus. Here we show evidence that EBLNs that were integrated into afrotherian genomes more than 83.3 million years ago have gained novel protein functions associated with rough endoplasmic reticulum in afrotherians. In the amino acid sequence of EBLN proteins, negative selection appeared to have operated more strongly on hydrophilic regions than on hydrophobic regions, suggesting that EBLN proteins may interact with other molecules in their host cells. In addition, we clarified the mechanism how EBLNs have acquired an ability to be transcribed in the host cell; they captured a partial duplicate of an intrinsic gene, transmembrane protein 106B, which retained an intrinsic promoter activity. Our findings suggest that not only retroviral EVEs but also non-retroviral EVEs may have contributed to the host evolution.
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Affiliation(s)
- Yuki Kobayashi
- Nihon University Veterinary Research Center, Fujisawa, Kanagawa, Japan
- * E-mail: (YK); (YS)
| | - Masayuki Horie
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
- United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Ayumi Nakano
- Nihon University Veterinary Research Center, Fujisawa, Kanagawa, Japan
| | - Koichi Murata
- Department of Animal Resource Science, College of Bioresource Sciences, Nihon Universitym, Fujisawa, Kanagawa, Japan
| | - Takuya Itou
- Nihon University Veterinary Research Center, Fujisawa, Kanagawa, Japan
| | - Yoshiyuki Suzuki
- Graduate School of Natural Sciences, Nagoya City University, Nagoya, Aichi, Japan
- * E-mail: (YK); (YS)
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Komorizono R, Makino A, Horie M, Honda T, Tomonaga K. Sequence determination of a new parrot bornavirus-5 strain in Japan: implications of clade-specific sequence diversity in the regions interacting with host factors. Microbiol Immunol 2016; 60:437-41. [DOI: 10.1111/1348-0421.12385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/12/2016] [Accepted: 05/05/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Ryo Komorizono
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
| | - Akiko Makino
- Department of Viral Oncology; Institute for Virus Research
- Center for Emerging Virus Research; Institute for Virus Research; Kyoto University
| | - Masayuki Horie
- Transboundary Animal Diseases Research Center; Joint Faculty of Veterinary Medicine; Kagoshima University
- United Graduate School of Veterinary Science; Yamaguchi University; Yamaguchi
| | - Tomoyuki Honda
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
| | - Keizo Tomonaga
- Department of Viral Oncology; Institute for Virus Research
- Department of Mammalian Regulatory Network; Graduate School of Biostudies
- Department of Tumor Viruses; Graduate School of Medicine; Kyoto University; Kyoto Japan
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Gillich N, Kuwata R, Isawa H, Horie M. Persistent natural infection of a Culex tritaeniorhynchus cell line with a novel Culex tritaeniorhynchus rhabdovirus strain. Microbiol Immunol 2016; 59:562-6. [PMID: 26112738 DOI: 10.1111/1348-0421.12279] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/29/2015] [Accepted: 06/22/2015] [Indexed: 12/25/2022]
Abstract
Culex tritaeniorhynchus rhabdovirus (CTRV) is a mosquito virus that establishes persistent infection without any obvious cell death. Therefore, occult infection by CTRV can be present in mosquito cell lines. In this study, it is shown that NIID-CTR cells, which were derived from Cx. tritaeniorhynchus, are persistently infected with a novel strain of CTRV. Complete genome sequencing of the infecting strain revealed that it is genetically similar but distinct from the previously isolated CTRV strain, excluding the possibility of contamination. These findings raise the importance of further CTRV studies, such as screening of CTRV in other mosquito cell lines.
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Affiliation(s)
- Nadine Gillich
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065.,Institute of Virology, University Medical Center Freiburg, Freiburg 79104, Germany
| | - Ryusei Kuwata
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640
| | - Masayuki Horie
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065.,United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8511, Japan
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Abstract
AbstractNatural bornavirus infections and their resulting diseases are largely restricted to horses and sheep in Central Europe. The disease also occurs naturally in cats, and can be induced experimentally in laboratory rodents and numerous other mammals. Borna disease virus-1 (BoDV-1), the cause of most cases of mammalian Borna disease, is a negative-stranded RNA virus that replicates within the nucleus of target cells. It causes severe, often lethal, encephalitis in susceptible species. Recent events, especially the discovery of numerous new species of bornaviruses in birds and a report of an acute, lethal bornaviral encephalitis in humans, apparently acquired from squirrels, have revived interest in this remarkable family of viruses. The clinical manifestations of the bornaviral diseases are highly variable. Thus, in addition to acute lethal encephalitis, they can cause persistent neurologic disease associated with diverse behavioral changes. They also cause a severe retinitis resulting in blindness. In this review, we discuss both the pathological lesions observed in mammalian bornaviral disease and the complex pathogenesis of the neurologic disease. Thus infected neurons may be destroyed by T-cell-mediated cytotoxicity. They may die as a result of excessive inflammatory cytokine release from microglia. They may also die as a result of a ‘glutaminergic storm’ due to a failure of infected astrocytes to regulate brain glutamate levels.
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Honda T, Yamamoto Y, Daito T, Matsumoto Y, Makino A, Tomonaga K. Long-term expression of miRNA for RNA interference using a novel vector system based on a negative-strand RNA virus. Sci Rep 2016; 6:26154. [PMID: 27189575 PMCID: PMC4870639 DOI: 10.1038/srep26154] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/19/2016] [Indexed: 01/28/2023] Open
Abstract
RNA interference (RNAi) has emerged as a promising technique for gene therapy. However, the safe and long-term expression of small RNA molecules is a major concern for the application of RNAi therapies in vivo. Borna disease virus (BDV), a non-segmented, negative-strand RNA virus, establishes a persistent infection without obvious cytopathic effects. Unique among animal non-retroviral RNA viruses, BDV persistently establishes a long-lasting persistent infection in the nucleus. These features make BDV ideal for RNA virus vector persistently expressing small RNAs. Here, we demonstrated that the recombinant BDV (rBDV) containing the miR-155 precursor, rBDV-miR-155, persistently expressed miR-155 and efficiently silenced its target gene. The stem region of the miR-155 precursor in rBDV-miR-155 was replaceable by any miRNA sequences of interest and that such rBDVs efficiently silence the expression of target genes. Collectively, BDV vector would be a novel RNA virus vector enabling the long-term expression of miRNAs for RNAi therapies.
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Affiliation(s)
- Tomoyuki Honda
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
| | - Yusuke Yamamoto
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
| | - Takuji Daito
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Yusuke Matsumoto
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Akiko Makino
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.,Center for Emerging Virus Research, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Keizo Tomonaga
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan.,Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto 606-8507, Japan
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An RNA-dependent RNA polymerase gene in bat genomes derived from an ancient negative-strand RNA virus. Sci Rep 2016; 6:25873. [PMID: 27174689 PMCID: PMC4865735 DOI: 10.1038/srep25873] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/22/2016] [Indexed: 12/28/2022] Open
Abstract
Endogenous bornavirus-like L (EBLL) elements are inheritable sequences derived from ancient bornavirus L genes that encode a viral RNA-dependent RNA polymerase (RdRp) in many eukaryotic genomes. Here, we demonstrate that bats of the genus Eptesicus have preserved for more than 11.8 million years an EBLL element named eEBLL-1, which has an intact open reading frame of 1,718 codons. The eEBLL-1 coding sequence revealed that functional motifs essential for mononegaviral RdRp activity are well conserved in the EBLL-1 genes. Genetic analyses showed that natural selection operated on eEBLL-1 during the evolution of Eptesicus. Notably, we detected efficient transcription of eEBLL-1 in tissues from Eptesicus bats. To the best of our knowledge, this study is the first report showing that the eukaryotic genome has gained a riboviral polymerase gene from an ancient virus that has the potential to encode a functional RdRp.
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Knock-Down of Endogenous Bornavirus-Like Nucleoprotein 1 Inhibits Cell Growth and Induces Apoptosis in Human Oligodendroglia Cells. Int J Mol Sci 2016; 17:435. [PMID: 27023521 PMCID: PMC4848891 DOI: 10.3390/ijms17040435] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 03/16/2016] [Accepted: 03/18/2016] [Indexed: 12/31/2022] Open
Abstract
Endogenous bornavirus-like nucleoprotein elements (EBLNs) have been discovered in the genomes of various animals including humans, whose functions have been seldom studied. To explore the biological functions of human EBLNs, we constructed a lentiviral vector expressing a short-hairpin RNA against human EBLN1, which successfully inhibited EBLN1 expression by above 80% in infected human oligodendroglia cells (OL cells). We found that EBLN1 silencing suppressed cell proliferation, induced G2/M phase arrest, and promoted apoptosis in OL cells. Gene expression profiling demonstrated that 1067 genes were up-regulated, and 2004 were down-regulated after EBLN1 silencing. The top 10 most upregulated genes were PI3, RND3, BLZF1, SOD2, EPGN, SBSN, INSIG1, OSMR, CREB3L2, and MSMO1, and the top 10 most-downregulated genes were KRTAP2-4, FLRT2, DIDO1, FAT4, ESCO2, ZNF804A, SUV420H1, ZC3H4, YAE1D1, and NCOA5. Pathway analysis revealed that these differentially expressed genes were mainly involved in pathways related to the cell cycle, the mitogen-activated protein kinase pathway, p53 signaling, and apoptosis. The gene expression profiles were validated by using quantitative reverse transcription polymerase chain reaction (RT-PCR) for detecting these 20 most-changed genes. Three genes closely related to glioma, RND3, OSMR, and CREB3L2, were significantly upregulated and might be the key factors in EBLN1 regulating the proliferation and apoptosis of OL cells. This study provides evidence that EBLN1 plays a key role in regulating cell life and death, thereby opening several avenues of investigation regarding EBLN1 in the future.
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Abstract
Borna disease virus (BDV), belonging to the non-segmented, negative-stranded RNA viruses, persistently infects the central nervous system of many mammals. Neonatal BDV infection in rodent models induces neurodevelopmental disturbance without overt inflammatory responses, resulting in a wide range of neurobehavioral abnormalities, such as anxiety, abnormal play behaviors, and cognitive deficits, resembling those of autism patients. Therefore, studies of BDV could provide a valuable model to investigate neuropathogenesis of neurodevelopmental disorders. However, the detailed neuropathogenesis of BDV has not been revealed. Here, we proposed two novel mechanisms that may contribute to BDV neuropathology. The first mechanism is abnormal IGF signaling. Using transgenic mice expressing BDV P protein in glial cells (P-Tg) that show neurobehavioral abnormalities resembling those in BDV-infected animals, we found that the upregulation of insulin-like growth factor (IGF) binding protein 3 in the astrocytes disturbs the IGF signaling and induces the Purkinje cell loss in BDV infection. The other is the integration of BDV sequences into the host genome. We recently found that BDV mRNAs are reverse-transcribed and integrated into the genome of infected cells. BDV integrants have the potential to produce their translated products or piRNAs, suggesting that BDV might exhibit the pathogenicity thorough these molecules. We also demonstrated that BDV integrants affect neighboring gene expression. Collectively, BDV integrants may alter transcriptome of infected cells, affecting BDV neuropathology.
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Abstract
Endogenous bornavirus-like elements (EBLs) are ancient bornavirus-derived sequence in the genomes of eukaryotes. Expression profile of EBLs suggests that, although most of the EBLs in mammalian genomes have lost their coding potential, many of them are transcribed in a cell-type specific or ubiquitous manner. This observation leads us to speculate that EBLs may have functions in their host cells. Here we describe possible functions of EBLs and their evolutionary significance. Our recent studies revealed that EBLs in some mammals, including humans, play critical roles in viral infection as either RNAs or proteins in previously undescribed mechanisms. Considering that species having EBLs in their genomes appear to be relatively resistance to BDV-mediated pathogenesis, endogenization of RNA viruses might be an evolutionarily inevitable event in the adaptation of hosts to the viruses.
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Affiliation(s)
- Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine
- Department of Viral Oncology, Institute for Virus Research, Kyoto University
| | - Keizo Tomonaga
- Department of Viral Oncology, Institute for Virus Research, Kyoto University
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Ferré CA, Davezac N, Thouard A, Peyrin JM, Belenguer P, Miquel MC, Gonzalez-Dunia D, Szelechowski M. Manipulation of the N-terminal sequence of the Borna disease virus X protein improves its mitochondrial targeting and neuroprotective potential. FASEB J 2015; 30:1523-33. [PMID: 26700735 DOI: 10.1096/fj.15-279620] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/08/2015] [Indexed: 01/11/2023]
Abstract
To favor their replication, viruses express proteins that target diverse mammalian cellular pathways. Due to the limited size of many viral genomes, such proteins are endowed with multiple functions, which require targeting to different subcellular compartments. One salient example is the X protein of Borna disease virus, which is expressed both at the mitochondria and in the nucleus. Moreover, we recently demonstrated that mitochondrial X protein is neuroprotective. In this study, we sought to examine the mechanisms whereby the X protein transits between subcellular compartments and to define its localization signals, to enhance its mitochondrial accumulation and thus, potentially, its neuroprotective activity. We transfected plasmids expressing fusion proteins bearing different domains of X fused to enhanced green fluorescent protein (eGFP) and compared their subcellular localization to that of eGFP. We observed that the 5-16 domain of X was responsible for both nuclear export and mitochondrial targeting and identified critical residues for mitochondrial localization. We next took advantage of these findings and constructed mutant X proteins that were targeted only to the mitochondria. Such mutants exhibited enhanced neuroprotective properties in compartmented cultures of neurons grown in microfluidic chambers, thereby confirming the parallel between mitochondrial accumulation of the X protein and its neuroprotective potential.-Ferré C. A., Davezac, N., Thouard, A., Peyrin, J. M., Belenguer, P., Miquel, M.-C., Gonzalez-Dunia, D., Szelechowski, M. Manipulation of the N-terminal sequence of the Borna disease virus X protein improves its mitochondrial targeting and neuroprotective potential.
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Affiliation(s)
- Cécile A Ferré
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Noélie Davezac
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Anne Thouard
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Jean-Michel Peyrin
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Pascale Belenguer
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Marie-Christine Miquel
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Daniel Gonzalez-Dunia
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Marion Szelechowski
- *INSERM, Unité Mixte de Recherche (UMR) 1043, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France; Centre National de la Recherche Scientifique (CNRS), UMR 5282, Toulouse, France; Université Toulouse III Paul Sabatier, Toulouse, France; CNRS UMR 5547, Centre de Biologie du Développement, Toulouse, France; CNRS UMR 8256, Biological Adaptation and Aging, Institut de Biologie Paris Seine, Université Pierre et Marie Curie, Paris, France; and Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
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Parrish NF, Fujino K, Shiromoto Y, Iwasaki YW, Ha H, Xing J, Makino A, Kuramochi-Miyagawa S, Nakano T, Siomi H, Honda T, Tomonaga K. piRNAs derived from ancient viral processed pseudogenes as transgenerational sequence-specific immune memory in mammals. RNA (NEW YORK, N.Y.) 2015; 21:1691-1703. [PMID: 26283688 PMCID: PMC4574747 DOI: 10.1261/rna.052092.115] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 07/08/2015] [Indexed: 06/04/2023]
Abstract
Endogenous bornavirus-like nucleoprotein elements (EBLNs) are sequences within vertebrate genomes derived from reverse transcription and integration of ancient bornaviral nucleoprotein mRNA via the host retrotransposon machinery. While species with EBLNs appear relatively resistant to bornaviral disease, the nature of this association is unclear. We hypothesized that EBLNs could give rise to antiviral interfering RNA in the form of PIWI-interacting RNAs (piRNAs), a class of small RNA known to silence transposons but not exogenous viruses. We found that in both rodents and primates, which acquired their EBLNs independently some 25-40 million years ago, EBLNs are present within piRNA-generating regions of the genome far more often than expected by chance alone (ℙ = 8 × 10(-3)-6 × 10(-8)). Three of the seven human EBLNs fall within annotated piRNA clusters and two marmoset EBLNs give rise to bona fide piRNAs. In both rats and mice, at least two of the five EBLNs give rise to abundant piRNAs in the male gonad. While no EBLNs are syntenic between rodent and primate, some of the piRNA clusters containing EBLNs are; thus we deduce that EBLNs were integrated into existing piRNA clusters. All true piRNAs derived from EBLNs are antisense relative to the proposed ancient bornaviral nucleoprotein mRNA. These observations are consistent with a role for EBLN-derived piRNA-like RNAs in interfering with ancient bornaviral infection. They raise the hypothesis that retrotransposon-dependent virus-to-host gene flow could engender RNA-mediated, sequence-specific antiviral immune memory in metazoans analogous to the CRISPR/Cas system in prokaryotes.
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Affiliation(s)
- Nicholas F Parrish
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Kan Fujino
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Yusuke Shiromoto
- Department of Pathology, Medical School and Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Yuka W Iwasaki
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hongseok Ha
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Jinchuan Xing
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Akiko Makino
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan Center for Emerging Virus Research, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Satomi Kuramochi-Miyagawa
- Department of Pathology, Medical School and Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Toru Nakano
- Department of Pathology, Medical School and Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Tomoyuki Honda
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Keizo Tomonaga
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
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41
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Hirai Y, Honda T, Makino A, Watanabe Y, Tomonaga K. X-linked RNA-binding motif protein (RBMX) is required for the maintenance of Borna disease virus nuclear viral factories. J Gen Virol 2015; 96:3198-3203. [PMID: 26333388 DOI: 10.1099/jgv.0.000273] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Borna disease virus (BDV) is a non-segmented, negative-strand RNA virus that establishes persistent infection in the nucleus. Although BDV forms viral inclusion bodies, termed viral speckles of transcripts (vSPOTs), which are associated with chromatin in the nucleus, the host factors involved in the maintenance of vSPOTs remain largely unknown. In this study, we identified X-linked RNA-binding motif protein (RBMX) as a nuclear factor interacting with BDV nucleoprotein. Interestingly, knockdown of RBMX led to disruption of the formation of vSPOTs and reduced both transcription and replication of BDV. Our results indicate that RBMX is involved in the maintenance of the structure of the virus factory in the nucleus.
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Affiliation(s)
- Yuya Hirai
- Department of Biology, Osaka Dental University, Osaka, Japan.,Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Tomoyuki Honda
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Akiko Makino
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto, Japan.,Center for Emerging Virus Research, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Yuzo Watanabe
- Department of Proteomics Facility, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Keizo Tomonaga
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto, Japan.,Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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42
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Marton S, Bányai K, Gál J, Ihász K, Kugler R, Lengyel G, Jakab F, Bakonyi T, Farkas SL. Coding-complete sequencing classifies parrot bornavirus 5 into a novel virus species. Arch Virol 2015; 160:2763-8. [PMID: 26282234 DOI: 10.1007/s00705-015-2546-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/18/2015] [Indexed: 11/26/2022]
Abstract
In this study, we determined the sequence of the coding region of an avian bornavirus detected in a blue-and-yellow macaw (Ara ararauna) with pathological/histopathological changes characteristic of proventricular dilatation disease. The genomic organization of the macaw bornavirus is similar to that of other bornaviruses, and its nucleotide sequence is nearly identical to the available partial parrot bornavirus 5 (PaBV-5) sequences. Phylogenetic analysis showed that these strains formed a monophyletic group distinct from other mammalian and avian bornaviruses and in calculations performed with matrix protein coding sequences, the PaBV-5 and PaBV-6 genotypes formed a common cluster, suggesting that according to the recently accepted classification system for bornaviruses, these two genotypes may belong to a new species, provisionally named Psittaciform 2 bornavirus.
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Affiliation(s)
- Szilvia Marton
- Centre for Agricultural Research, Institute for Veterinary Medical Research, Hungarian Academy of Sciences, Hungária krt. 21, 1581, Budapest, Hungary
| | - Krisztián Bányai
- Centre for Agricultural Research, Institute for Veterinary Medical Research, Hungarian Academy of Sciences, Hungária krt. 21, 1581, Budapest, Hungary
| | - János Gál
- Department of Exotic Animal and Wildlife Medicine, Faculty of Veterinary Science, Szent István University, István u. 2, 1078, Budapest, Hungary
| | - Katalin Ihász
- Centre for Agricultural Research, Institute for Veterinary Medical Research, Hungarian Academy of Sciences, Hungária krt. 21, 1581, Budapest, Hungary
| | - Renáta Kugler
- Centre for Agricultural Research, Institute for Veterinary Medical Research, Hungarian Academy of Sciences, Hungária krt. 21, 1581, Budapest, Hungary
| | - György Lengyel
- Medical Centre of Hungarian Defense Forces, Force Health Laboratory Institute, Róbert Károly krt. 44, 1134, Budapest, Hungary
| | - Ferenc Jakab
- János Szentágothai Research Centre, University of Pécs, Ifjúság útja 20, 7624, Pecs, Hungary
| | - Tamás Bakonyi
- Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, Hungária krt. 23-25, 1143, Budapest, Hungary
| | - Szilvia L Farkas
- Centre for Agricultural Research, Institute for Veterinary Medical Research, Hungarian Academy of Sciences, Hungária krt. 21, 1581, Budapest, Hungary.
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Makino A, Fujino K, Parrish NF, Honda T, Tomonaga K. Borna disease virus possesses an NF-ĸB inhibitory sequence in the nucleoprotein gene. Sci Rep 2015; 5:8696. [PMID: 25733193 PMCID: PMC4649702 DOI: 10.1038/srep08696] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/02/2015] [Indexed: 02/06/2023] Open
Abstract
Borna disease virus (BDV) has a non-segmented, negative-stranded RNA genome and causes persistent infection in many animal species. Previous study has shown that the activation of the IκB kinase (IKK)/NF-κB pathway is reduced by BDV infection even in cells expressing constitutively active mutant IKK. This result suggests that BDV directly interferes with the IKK/NF-κB pathway. To elucidate the mechanism for the inhibition of NF-κB activation by BDV infection, we evaluated the cross-talk between BDV infection and the NF-κB pathway. Using Multiple EM for Motif Elicitation analysis, we found that the nucleoproteins of BDV (BDV-N) and NF-κB1 share a common ankyrin-like motif. When THP1-CD14 cells were pre-treated with the identified peptide, NF-κB activation by Toll-like receptor ligands was suppressed. The 20S proteasome assay showed that BDV-N and BDV-N-derived peptide inhibited the processing of NF-κB1 p105 into p50. Furthermore, immunoprecipitation assays showed that BDV-N interacted with NF-κB1 but not with NF-κB2, which shares no common motif with BDV-N. These results suggest BDV-N inhibits NF-κB1 processing by the 20S proteasome through its ankyrin-like peptide sequence, resulting in the suppression of IKK/NF-κB pathway activation. This inhibitory effect of BDV on the induction of the host innate immunity might provide benefits against persistent BDV infection.
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Affiliation(s)
- Akiko Makino
- 1] Department of Viral Oncology, Kyoto University, Kyoto 606-8507, Japan [2] Center for Emerging Virus Research, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Kan Fujino
- Department of Viral Oncology, Kyoto University, Kyoto 606-8507, Japan
| | | | - Tomoyuki Honda
- 1] Department of Viral Oncology, Kyoto University, Kyoto 606-8507, Japan [2] Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Keizo Tomonaga
- 1] Department of Viral Oncology, Kyoto University, Kyoto 606-8507, Japan [2] Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan [3] Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
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Kojima S, Honda T, Matsumoto Y, Tomonaga K. Heat stress is a potent stimulus for enhancing rescue efficiency of recombinant Borna disease virus. Microbiol Immunol 2014; 58:636-42. [DOI: 10.1111/1348-0421.12193] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/23/2014] [Accepted: 08/19/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Shohei Kojima
- Department of Viral Oncology; Institute for Virus Research; Kyoto University; 53 Kawahara-cho Shogoin Sakyo-ku Kyoto 606-8507
| | - Tomoyuki Honda
- Department of Viral Oncology; Institute for Virus Research; Kyoto University; 53 Kawahara-cho Shogoin Sakyo-ku Kyoto 606-8507
| | - Yusuke Matsumoto
- Department of Viral Oncology; Institute for Virus Research; Kyoto University; 53 Kawahara-cho Shogoin Sakyo-ku Kyoto 606-8507
- Department of Microbiology; School of Medicine; Wakayama Medical University; 811-1 Kimiidera Wakayama 641-8509 Japan
| | - Keizo Tomonaga
- Department of Viral Oncology; Institute for Virus Research; Kyoto University; 53 Kawahara-cho Shogoin Sakyo-ku Kyoto 606-8507
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45
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A viral peptide that targets mitochondria protects against neuronal degeneration in models of Parkinson’s disease. Nat Commun 2014; 5:5181. [DOI: 10.1038/ncomms6181] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 09/05/2014] [Indexed: 12/27/2022] Open
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Inhibition of Borna disease virus replication by an endogenous bornavirus-like element in the ground squirrel genome. Proc Natl Acad Sci U S A 2014; 111:13175-80. [PMID: 25157155 DOI: 10.1073/pnas.1407046111] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animal genomes contain endogenous viral sequences, such as endogenous retroviruses and retrotransposons. Recently, we and others discovered that nonretroviral viruses also have been endogenized in many vertebrate genomes. Bornaviruses belong to the Mononegavirales and have left endogenous fragments, called "endogenous bornavirus-like elements" (EBLs), in the genomes of many mammals. The striking features of EBLs are that they contain relatively long ORFs which have high sequence homology to the extant bornavirus proteins. Furthermore, some EBLs derived from bornavirus nucleoprotein (EBLNs) have been shown to be transcribed as mRNA and probably are translated into proteins. These features lead us to speculate that EBLs may function as cellular coopted genes. An EBLN element in the genome of the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), itEBLN, encodes an ORF with 77% amino acid sequence identity to the current bornavirus nucleoprotein. In this study, we cloned itEBLN from the ground squirrel genome and investigated its involvement in Borna disease virus (BDV) replication. Interestingly, itEBLN, but not a human EBLN, colocalized with the viral factory in the nucleus and appeared to affect BDV polymerase activity by being incorporated into the viral ribonucleoprotein. Our data show that, as do certain endogenous retroviruses, itEBLN potentially may inhibit infection by related exogenous viruses in vivo.
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Borna disease virus infection in cats. Vet J 2013; 201:142-9. [PMID: 24480411 DOI: 10.1016/j.tvjl.2013.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/05/2013] [Accepted: 12/05/2013] [Indexed: 01/13/2023]
Abstract
Bornaviruses are known to cause neurological disorders in a number of animal species. Avian Bornavirus (ABV) causes proventricular dilatation disease (PDD) in birds and Borna disease virus (BDV) causes Borna disease in horses and sheep. BDV also causes staggering disease in cats, characterised by ataxia, behavioural changes and loss of postural reactions. BDV-infection markers in cats have been reported throughout the world. This review summarizes the current knowledge of Borna disease viruses in cats, including etiological agent, clinical signs, pathogenesis, epidemiology and diagnostics, with comparisons to Bornavirus infections in other species.
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Horie M, Kobayashi Y, Suzuki Y, Tomonaga K. Comprehensive analysis of endogenous bornavirus-like elements in eukaryote genomes. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120499. [PMID: 23938751 DOI: 10.1098/rstb.2012.0499] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bornaviruses are the only animal RNA viruses that establish a persistent infection in their host cell nucleus. Studies of bornaviruses have provided unique information about viral replication strategies and virus-host interactions. Although bornaviruses do not integrate into the host genome during their replication cycle, we and others have recently reported that there are DNA sequences derived from the mRNAs of ancient bornaviruses in the genomes of vertebrates, including humans, and these have been designated endogenous borna-like (EBL) elements. Therefore, bornaviruses have been interacting with their hosts as driving forces in the evolution of host genomes in a previously unexpected way. Studies of EBL elements have provided new models for virology, evolutionary biology and general cell biology. In this review, we summarize the data on EBL elements including what we have newly identified in eukaryotes genomes, and discuss the biological significance of EBL elements, with a focus on EBL nucleoprotein elements in mammalian genomes. Surprisingly, EBL elements were detected in the genomes of invertebrates, suggesting that the host range of bornaviruses may be much wider than previously thought. We also review our new data on non-retroviral integration of Borna disease virus.
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Affiliation(s)
- Masayuki Horie
- Department of Virology, Institute for Medical Microbiology and Hygiene, University of Freiburg, , 79104 Freiburg, Germany
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Nucleocytoplasmic shuttling of viral proteins in borna disease virus infection. Viruses 2013; 5:1978-90. [PMID: 23965528 PMCID: PMC3761237 DOI: 10.3390/v5081978] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 12/20/2022] Open
Abstract
Nuclear import and export of viral RNA and proteins are critical to the replication cycle of viruses that replicate in the nucleus. Borna disease virus (BDV) is a nonsegmented, negative-strand RNA virus that belongs to the order Mononegavirales. BDV has several distinguishing features, one of the most striking being the site of its replication. BDV RNA is transcribed and replicated in the nucleus, while most other negative-strand RNA viruses replicate in the cytoplasm. Therefore, the nucleocytoplasmic trafficking of BDV macromolecules plays a key role in virus replication. Growing evidence indicates that several BDV proteins, including the nucleoprotein, phosphoprotein, protein X and large protein, contribute to the nucleocytoplasmic trafficking of BDV ribonucleoprotein (RNP). The directional control of BDV RNP trafficking is likely determined by the ratios of and interactions between the nuclear localization signals and nuclear export signals in the RNP. In this review, we present a comprehensive view of several unique mechanisms that BDV has developed to control its RNP trafficking and discuss the significance of BDV RNP trafficking in the replication cycle of BDV.
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Abstract
In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10-20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.
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