研究者詳細 - 本田　知之

Antiviral activity of favipiravir (T-705) against mammalian and avian bornaviruses 査読

Tomoya Tokunaga, Yusuke Yamamoto, Madoka Sakai, Keizo Tomonaga, Tomoyuki Honda

ANTIVIRAL RESEARCH 143 237 - 245 2017年7月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Bornaviruses, non-segmented, negative-strand RNA viruses, are emerging agents with the potential for causing various types of neurological symptoms. Previous studies have shown that ribavirin, a nucleic acid analog with broad-spectrum antiviral activity, has a potent antiviral effect on infections with a mammalian bornavirus, Borna disease virus (BoDV-1), as well as avian bornaviruses. However, ribavirin based treatment does not eliminate bornaviruses from persistently infected cells and viral replication resumes after treatment cessation. Therefore, the development of a novel effective anti-bornavirus treatment is needed. To identify such agents, we screened nucleoside/nucleotide mimetics for agents with anti-bornavirus activity. We used Vero cells infected with recombinant BoDV-1 carrying Gaussia luciferase to monitor BoDV-1 replication and found that favipiravir (T-705) is a potent inhibitor of BoDV1 replication. T-705 suppressed BoDV-1 replication in a dose-and time-dependent manner during the observation period of 4 weeks. Notably, no increase in luciferase activity or in the number of BoDV-1positive cells was detected in the at least 4 weeks following T-705 removal. Finally, we demonstrated that T-705 effectively suppressed viral replication of both BoDV-1 and an avian bornavirus, suggesting that T-705 may have a strong antiviral activity against a broad range of bornaviruses. Our findings provide a novel and effective option for treating persistent bornavirus infection. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.antiviral.2017.04.018

The P gene of rodent brain-adapted measles virus plays a critical role in neurovirulence 査読

Tetsuro Arai, Yuri Terao-Muto, Shotaro Uchida, Che Lin, Tomoyuki Honda, Akiko Takenaka, Fusako Ikeda, Hiroki Sato, Misako Yoneda, Chieko Kai

JOURNAL OF GENERAL VIROLOGY 98 ( 7 ) 1620 - 1629 2017年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MICROBIOLOGY SOC

In rare cases, measles virus (MV) in children leads to fatal neurological complications such as primary measles encephalitis, post-acute measles encephalitis, subacute sclerosing panencephalitis and measles inclusion-body encephalitis. To investigate the pathogenesis of MV-induced encephalitis, rodent brain-adapted MV strains CAM/RB and CAMR40 were generated. These strains acquired mutations to adapt to the rodent brain during 40 passages in rat brain. However, it is still unknown which genes confer the neurovirulence of MV. We previously established a rescue system for recombinant MVs possessing the backbone of wild-type strain HL, an avirulent strain in mice. In the present study, to identify the genes in CAMR40 that elicit neurovirulence, we generated chimeric recombinant MVs based on strain HL. As a result, recombinant wild-type MV in which the haemagglutinin (H) gene was substituted with that of CAMR40 caused a non-lethal mild disease in mice, while additional substitution of the HL phosphoprotein (P) gene with that of strain CAMR40 caused lethal severe neurological signs comparable to those of CAMR40. These results clearly indicated that, in addition to the H gene, the P gene is required for the neurovirulence of MV CAMR40.

DOI： 10.1099/jgv.0.000842

突然の健忘で発症し精神症状等を合併した抗ボルナウイルス抗体陽性の2症例査読

松永秀典, 陸馨仙, 福本素由己, 金井講治, 近江翼, 大村夕美, 本田知之, 朝長啓造

精神神経学雑誌 ( 2017特別号 ) S504 - S504 2017年6月

Detection of Antibodies against Borna Disease Virus Proteins in an Autistic Child and Her Mother 査読

Tomoyuki Honda, Kozue Sofuku, Hidenori Matsunaga, Masaya Tachibana, Ikuko Mohri, Masako Taniike, Keizo Tomonaga

JAPANESE JOURNAL OF INFECTIOUS DISEASES 70 ( 2 ) 225 - 227 2017年3月

Borna Disease Virus Assembles Porous Cage-like Viral Factories in the Nucleus 査読

Yuya Hirai, Yasuhiro Hirano, Atsushi Matsuda, Yasushi Hiraoka, Tomoyuki Honda, Keizo Tomonaga

JOURNAL OF BIOLOGICAL CHEMISTRY 291 ( 50 ) 25789 - 25798 2016年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

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.

DOI： 10.1074/jbc.M116.746396

Measles virus induces persistent infection by autoregulation of viral replication 査読

Tomomitsu Doi, Hyun-Jeong Kwon, Tomoyuki Honda, Hiroki Sato, Misako Yoneda, Chieko Kai

SCIENTIFIC REPORTS 6 37163 2016年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

Natural infection with measles virus (MV) establishes lifelong immunity. Persistent infection with MV is likely involved in this phenomenon, as non-replicating protein antigens never induce such long-term immunity. Although MV establishes stable persistent infection in vitro and possibly in vivo, the mechanism by which this occurs is largely unknown. Here, we demonstrate that MV changes the infection mode from lytic to non-lytic and evades the innate immune response to establish persistent infection without viral genome mutation. We found that, in the persistent phase, the viral RNA level declined with the termination of interferon production and cell death. Our analysis of viral protein dynamics shows that during the establishment of persistent infection, the nucleoprotein level was sustained while the phosphoprotein and large protein levels declined. The ectopic expression of nucleoprotein suppressed viral replication, indicating that viral replication is self-regulated by nucleoprotein accumulation during persistent infection. The persistently infected cells were able to produce interferon in response to poly I:C stimulation, suggesting that MV does not interfere with host interferon responses in persistent infection. Our results may provide mechanistic insight into the persistent infection of this cytopathic RNA virus that induces lifelong immunity.

DOI： 10.1038/srep37163

ドイツで死亡した3人の脳炎患者から発見されたカワリリスボルナウイルス(VSBV-1)に対する抗体測定の試み

松永秀典, 本田知之, 近江翼, 陸馨仙, 福本素由己, 金井講治, 大村夕美, 朝長啓造

NEUROINFECTION 21 ( 2 ) 207 - 207 2016年9月

Sequence determination of a new parrot bornavirus-5 strain in Japan: implications of clade-specific sequence diversity in the regions interacting with host factors 査読

Ryo Komorizono, Akiko Makino, Masayuki Horie, Tomoyuki Honda, Keizo Tomonaga

MICROBIOLOGY AND IMMUNOLOGY 60 ( 6 ) 437 - 441 2016年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

In this study, the genome sequence of a new parrot bornavirus-5 (PaBV-5) detected in Eclectus roratus was determined. Phylogenetic analysis showed that the genus Bornavirus is divided into three major clades and that PaBV-5 belongs to clade 2, which contains avian viruses that exhibit infectivity to mammalian cells. Sequence comparisons of the regions known to interact with host factors indicated that the clade 2 avian viruses possess sequences intermediate between the clade 1 mammalian viruses and the clade 3 avian viruses, suggesting that the identified regions might contribute to the differences in virological properties between the three clades.

DOI： 10.1111/1348-0421.12385

An RNA-dependent RNA polymerase gene in bat genomes derived from an ancient negative-strand RNA virus 査読

Masayuki Horie, Yuki Kobayashi, Tomoyuki Honda, Kan Fujino, Takumi Akasaka, Claudia Kohl, Gudrun Wibbelt, Kristin Muehldorfer, Andreas Kurth, Marcel A. Mueller, Victor M. Corman, Nadine Gillich, Yoshiyuki Suzuki, Martin Schwemmle, Keizo Tomonaga

SCIENTIFIC REPORTS 6 25873 2016年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

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.

DOI： 10.1038/srep25873

Links between Human LINE-1 Retrotransposons and Hepatitis Virus-Related Hepatocellular Carcinoma 査読

Tomoyuki Honda

FRONTIERS IN CHEMISTRY 4 21 2016年5月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：FRONTIERS MEDIA SA

Hepatocellular carcinoma (HCC) accounts for approximately 80% of liver cancers, the third most frequent cause of cancer mortality. The most prevalent risk factors for HCC are infections by hepatitis B or hepatitis C virus. Findings suggest that hepatitis virus-related HCC might be a cancer in which LINE-1 retrotransposon, often termed L1, activity plays a potential role. Firstly, hepatitis viruses can suppress host defense factors that also control L1 mobilization. Secondly, many recent studies also have indicated that hypomethylation of L1 affects the prognosis of HCC patients. Thirdly, endogenous L1 retrotransposition was demonstrated to activate oncogenic pathways in HCC. Fourthly, several L1 chimeric transcripts with host or viral genes are found in hepatitis virus-related HCC. Such lines of evidence suggest a linkage between L1 retrotransposons and hepatitis virus-related HCC. Here, I briefly summarize current understandings of the association between hepatitis virus-related HCC and L1. Then, I discuss potential mechanisms of how hepatitis viruses drive the development of HCC via L1 retrotransposons. An increased understanding of the contribution of L1 to hepatitis virus-related HCC may provide unique insights related to the development of novel therapeutics for this disease.

DOI： 10.3389/fchem.2016.00021

Long-term expression of miRNA for RNA interference using a novel vector system based on a negative-strand RNA virus 査読

Tomoyuki Honda, Yusuke Yamamoto, Takuji Daito, Yusuke Matsumoto, Akiko Makino, Keizo Tomonaga

SCIENTIFIC REPORTS 6 26154 2016年5月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

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.

DOI： 10.1038/srep26154

Influenza A Virus-Induced Expression of a GalNAc Transferase, GALNT3, via MicroRNAs Is Required for Enhanced Viral Replication 査読

Shoko Nakamura, Masayuki Horie, Tomo Daidoji, Tomoyuki Honda, Mayo Yasugi, Atsushi Kuno, Toshihisa Komori, Daisuke Okuzaki, Hisashi Narimatsu, Takaaki Nakaya, Keizo Tomonaga

JOURNAL OF VIROLOGY 90 ( 4 ) 1788 - 1801 2016年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC MICROBIOLOGY

Influenza A virus (IAV) affects the upper and lower respiratory tracts and rapidly induces the expression of mucins, which are common O-glycosylated proteins, on the epithelial surfaces of the respiratory tract. Although mucin production is associated with the inhibition of virus transmission as well as characteristic clinical symptoms, little is known regarding how mucins are produced on the surfaces of respiratory epithelial cells and how they affect IAV replication. In this study, we found that two microRNAs (miRNAs), miR-17-3p and miR-221, which target GalNAc transferase 3 (GALNT3) mRNA, are rapidly downregulated in human alveolar basal epithelial cells during the early stage of IAV infection. We demonstrated that the expression of GALNT3 mRNA is upregulated in an IAV replication-dependent fashion and leads to mucin production in bronchial epithelial cells. A lectin microarray analysis revealed that the stable expression of GALNT3 by human alveolar basal epithelial cells induces mucin-type O-glycosylation modifications similar to those present in IAV-infected cells, suggesting that GALNT3 promotes mucin-type O-linked glycosylation in IAV-infected cells. Notably, analyses using short interfering RNAs and miRNA mimics showed that GALNT3 knockdown significantly reduces IAV replication. Furthermore, IAV replication was markedly decreased in embryonic fibroblast cells obtained from galnt3-knockout mice. Interestingly, IAV-infected galnt3-knockout mice exhibited high mortality and severe pathological alterations in the lungs compared to those of wild-type mice. Our results demonstrate not only the molecular mechanism underlying rapid mucin production during IAV infection but also the contribution of O-linked glycosylation to the replication and propagation of IAV in lung cells.

DOI： 10.1128/JVI.02246-15

内在性RNAウイルスエレメントによるウイルスRNA制御仮説

本田知之, 朝長啓造

ウイルス 66 ( 1 ) 39 - 46 2016年

Endogenous non-retroviral RNA virus elements evidence a novel type of antiviral immunity 査読

Tomoyuki Honda, Keizo Tomonaga

Mobile Genetic Elements 6 ( 3 ) e1165785 2016年

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Taylor and Francis Inc.

Vertebrate genomes contain many virus-related sequences derived from both retroviruses and nonretroviral RNA and DNA viruses. Such non-retroviral RNA sequences are possibly produced by reverse-transcription and integration of viral mRNAs of ancient RNA viruses using retrotransposon machineries. We refer to this process as transcript reversion. During an ancient bornavirus infection, transcript reversion may have left bornavirus-related sequences, known as endogenous bornaviruslike nucleoproteins (EBLNs), in the genome. We have recently demonstrated that all Homo sapiens EBLNs are expressed in at least one tissue. Because species with EBLNs appear relatively protected against infection by a current bornavirus, Borna disease virus, it is speculated that EBLNs play some roles in antiviral immunity, as seen with some endogenous retroviruses. EBLNs can function as dominant negative forms of viral proteins, small RNAs targeting viral sequences, or DNA or RNA elements modulating the gene expression. Growing evidence reveals that various RNA viruses are reverse-transcribed and integrated into the genome of infected cells, suggesting transcript reversion generally occurs during ongoing infection. Considering this, transcript reversion-mediated interference with related viruses may be a novel type of antiviral immunity in vertebrates. Understanding the biological significance of transcript reversion will provide novel insights into host defenses against viral infections.

DOI： 10.1080/2159256X.2016.1165785

Scopus

Possible roles of endogenous RNA virus elements in RNA virus infection. 査読

Honda T, Tomonaga K

Uirusu 66 ( 1 ) 39 - 46 2016年

X-linked RNA-binding motif protein (RBMX) is required for the maintenance of Borna disease virus nuclear viral factories 査読

Yuya Hirai, Tomoyuki Honda, Akiko Makino, Yuzo Watanabe, Keizo Tomonaga

JOURNAL OF GENERAL VIROLOGY 96 ( 11 ) 3198 - 3203 2015年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC GENERAL MICROBIOLOGY

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.

DOI： 10.1099/jgv.0.000273

piRNAs derived from ancient viral processed pseudogenes as transgenerational sequence-specific immune memory in mammals 査読

Nicholas F. Parrish, Kan Fujino, Yusuke Shiromoto, Yuka W. Iwasaki, Hongseok Ha, Jinchuan Xing, Akiko Makino, Satomi Kuramochi-Miyagawa, Toru Nakano, Haruhiko Siomi, Tomoyuki Honda, Keizo Tomonaga

RNA 21 ( 10 ) 1691 - 1703 2015年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT

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 x 10(-3) -6 x 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.

DOI： 10.1261/rna.052092.115

Transcription Profiling Demonstrates Epigenetic Control of Non-retroviral RNA Virus-Derived Elements in the Human Genome 査読

Kozue Sofuku, Nicholas F. Parrish, Tomoyuki Honda, Keizo Tomonaga

CELL REPORTS 12 ( 10 ) 1548 - 1554 2015年9月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CELL PRESS

Endogenous bornavirus-like nucleoprotein elements (EBLNs) are DNA sequences in vertebrate genomes formed by the retrotransposon-mediated integration of ancient bornavirus sequence. Thus, EBLNs evidence a mechanism of retrotransposon-mediated RNA-to-DNA information flow from environment to animals. Although EBLNs are non-transposable, they share some features with retrotransposons. Here, to test whether hosts control the expression of EBLNs similarly to retrotransposons, we profiled the transcription of all Homo sapiens EBLNs (hsEBLN-1 to hsEBLN-7). We could detect transcription of all hsEBLNs in at least one tissue. Among them, hsEBLN-1 is transcribed almost exclusively in the testis. In most tissues, expression from the hsEBLN-1 locus is silenced epigenetically. Finally, we showed the possibility that hsEBLN-1 integration at this locus affects the expression of a neighboring gene. Our results suggest that hosts regulate the expression of endogenous non-retroviral virus elements similarly to how they regulate the expression of retrotransposons, possibly contributing to new transcripts and regulatory complexity to the human genome.

DOI： 10.1016/j.celrep.2015.08.007