Language：English   Publishing type：Research paper (scientific journal)   Publisher：Infectious Diseases of Poverty  

BACKGROUND: Chongming Island in China serves as a breeding and shelter point on the East Asian-Australasian Flyway. The resting frequency of migratory birds, abundance of mosquito populations, and the popular domestic poultry industry pose a potential risk of mosquito-borne zoonotic diseases. The aim of this study is to explore the role of migratory birds in the spread of mosquito-borne pathogens and their prevalent status on the island. METHODS: We conducted a mosquito-borne pathogen surveillance in 2021, in Chongming, Shanghai, China. Approximately 67,800 adult mosquitoes belonging to ten species were collected to investigate the presence of flaviviruses, alphaviruses, and orthobunyaviruses by RT-PCR. Genetic and phylogenetic analyses were conducted to explore the virus genotype and potential nature source. Serological survey was performed by ELISA to characterize Tembusu virus (TMUV) infection among domestic poultry. RESULTS: Two strains of TMUV and Chaoyang virus (CHAOV) and 47 strains of Quang Binh virus (QBV) were detected in 412 mosquito pools, with the infection rate of 0.16, 0.16, and 3.92 per 1000 Culex tritaeniorhynchus, respectively. Furthermore, TMUVs viral RNA was found in serum samples of domestic chickens and faecal samples of migratory birds. Antibodies against TMUV were detected in domestic avian serum samples, generally ranging from 44.07% in pigeons to 55.71% in ducks. Phylogenetic analyses indicated that the TMUV detected in Chongming belonged to Cluster 3, Southeast Asia origin, and most closely related to the CTLN strain, which caused a TMUV outbreak in chickens in Guangdong Province in 2020, but distant from strains obtained previously in Shanghai, which were involved in the 2010 TMUV outbreak in China. CONCLUSIONS: We speculate that the TMUV was imported to Chongming Island through long-distance spreading by migratory birds from Southeast Asia, followed by spill over and transmission in mosquitoes and domestic avian species, threatening the local domestic poultry. In addition, the expansion and prevalence of insect-specific flaviviruses and its simultaneous circulation with mosquito-borne virus are worthy of close attention and further study.

DOI： 10.1186/s40249-023-01098-9

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Vaccine  

Noroviruses (NoVs) are one of the major causes of acute viral gastroenteritis in humans. Virus-like particles (VLPs) without genomes that mimic the capsid structure of viruses are promising vaccine candidates for the prevention of NoVs infection. To produce large amounts of recombinant protein, including VLPs, the silkworm-expression vector system (silkworm-BEVS) is an efficient and powerful tool. In this study, we constructed a recombinant baculovirus that expresses VP1 protein, the major structural protein of NoV GII.4. Expression analysis showed that the baculovirus-infected silkworm pupae expressed NoV VP1 protein more efficiently than silkworm larval fat bodies. We obtained about 4.9 mg of purified NoV VP1 protein from only five silkworm pupae. The purified VP1 protein was confirmed by dynamic light scattering and electron microscopy to form VLPs of approximately 40 nm in diameter. Antisera from mice immunized with the antigen blocked NoV VLPs binding to histo-blood group antigens of pig gastric mucin and also blocked NoV infection in intestinal epithelial cells derived from human induced pluripotent stem (iPS) cells. Our findings demonstrated that NoV VLP eliciting protective antibodies could be obtained in milligram quantities from a few silkworm pupae using the silkworm-BEVS.

DOI： 10.1016/j.vaccine.2022.12.015

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Language：Japanese   Publisher：日本衛生動物学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ClinMed International Library  

DOI： 10.23937/2643-461x/1710062

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Insect Biochemistry and Molecular Biology  

The ovary is an important organ in reproduction. In insects, especially lepidopteran insects, the oocytes and reproductive organs develop rapidly during the pupal stage. Despite their drastic morphological changes, the molecular mechanisms of ovary development are not fully understood. In this study, it is found that forkhead box transcription factor L2, member 1 (FoxL21), which is known to be involved in ovarian differentiation and maintenance in vertebrates, is required for the development of the ovary in the silkworm, Bombyx mori. FoxL21 was expressed in the ovary and ovariole during the larval and pupal stage, respectively. In silkworms in which FoxL21 was knocked out by genome editing, multiple ovarian dysfunctions, such as, abnormal egg formation, thinning of the ovariole sheaths, and defective connection of the oviductus geminus with the ovariole were observed. Finally, ovarian transplantation experiments using the knockout silkworms revealed that FoxL21 functions in the ovariole, but not in the oviductus geminus.

DOI： 10.1016/j.ibmb.2022.103737

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Jingmen tick virus (JMTV) and the related jingmenvirus-termed Alongshan virus are recognized as globally emerging human pathogenic tick-borne viruses. These viruses have been detected in various mammals and invertebrates, although their natural transmission cycles remain unknown. JMTV and a novel jingmenvirus, tentatively named Takachi virus (TAKV), have now been identified during a surveillance of tick-borne viruses in Japan. JMTV was shown to be distributed across extensive areas of Japan and has been detected repeatedly at the same collection sites over several years, suggesting viral circulation in natural transmission cycles in these areas. Interestingly, these jingmenviruses may exist in a host tick species-specific manner. Vertical transmission of the virus in host ticks in nature was also indicated by the presence of JMTV in unfed host-questing Amblyomma testudinarium larvae. Further epidemiological surveillance and etiological studies are necessary to assess the status and risk of jingmenvirus infection in Japan.

DOI： 10.3390/v13122547

Language：English   Publishing type：Research paper (scientific journal)  

Among the inheritance of cellular components during cell division, deoxyribonucleic acid (DNA) and its condensate (chromosome) are conventionally visualized using chemical tag-labeled nucleotide analogs. However, associated mutagenesis with nucleotide analogs in the visualization of chromosomes is cause for concern. This study investigated the efficiency of using stable isotope labels in visualizing the replicating cultured human cell-chromosomes, in the absence of analog labels, at a high spatial resolution of 100 nm. The distinct carbon isotope ratio between sister chromatids reflected the semi-conservative replication of individual DNA strands through cell cycles and suggested the renewal of histone molecules in daughter chromosomes. Thus, this study provides a new, powerful approach to trace and visualize cellular components with stable isotope labeling.Key words: stable isotope, chromosome replication, semi-conservative replication, imaging, mass spectrometry.

DOI： 10.1247/csf.21011

Language：English   Publishing type：Research paper (scientific journal)  

COVID-19, caused by SARS-CoV-2, is currently spreading around the world and causing many casualties. Antibodies against such emerging infectious diseases are one of the important tools for basic viral research and the development of diagnostic and therapeutic agents. CR3022 is a monoclonal antibody against the receptor binding domain (RBD) of the spike protein (S protein) of SARS-CoV found in SARS patients, but it was also shown to have strong affinity for that of SARS-CoV-2. In this study, we produced large amounts of three formats of CR3022 antibodies (scFv, Fab and IgG) with high purity using a silkworm-baculovirus expression vector system. Furthermore, SPR measurements showed that the affinity of those silkworm-produced IgG antibodies to S protein was almost the same as that produced in mammalian expression system. These results indicate that the silkworm-baculovirus expression system is an excellent expression system for emerging infectious diseases that require urgent demand for diagnostic agents and therapeutic agents.

DOI： 10.1007/s12033-021-00373-0

Language：English   Publishing type：Research paper (scientific journal)  

Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen of watery diarrhea that causes serious economic loss to the swine industry worldwide. Especially because of the high mortality rate in neonatal piglets, a vaccine with less production cost and high protective effect against PEDV is desired. The intrinsically assembled homotrimer of spike (S) protein on the PEDV viral membrane contributing to the host cell entry is a target of vaccine development. In this study, we designed trimerized PEDV S protein for efficient production in the silkworm-baculovirus expression vector system (silkworm-BEVS) and evaluated its immunogenicity in the mouse. The genetic fusion of the trimeric motif improved the expression of S protein in silkworm-BEVS. A small-scale screening of silkworm strains to further improve the S protein productivity finally achieved the yield of about 2 mg from the 10 mL larval serum. Mouse immunization study demonstrated that the trimerized S protein could elicit strong humoral immunity, including the S protein-specific IgG in the serum. These sera contained neutralizing antibodies that can protect Vero cells from PEDV infection. These results demonstrated that silkworm-BEVS provides a platform for the production of trimeric S proteins, which are promising subunit vaccines against coronaviruses such as PEDV.

DOI： 10.1186/s13567-021-00971-5

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Dengue virus (DENV) is a mosquito-borne arbovirus transmitted by Aedes mosquitoes, but is not endemic in all areas where this vector is found. For example, the relatively sparse distribution of cases in West Africa is generally attributed to the refractory nature of West African Aedes aegypti (Ae. aegypti) to DENV infection, and particularly the forest-dwelling Ae. aegypti formosus. However, recent studies have shown these mosquitoes to be competent vectors within some West African countries that have suffered outbreaks in the past, such as Senegal. There is however little information on the vector competence of the Ae. aegypti in West African countries such as Ghana with no reported outbreaks. METHODS: This study examined the vector competence of 4 Ae. aegypti colonies from urban, semi-urban, and two rural locations in Ghana in transmitting DENV serotypes 1 and 2, using a single colony from Vietnam as control. Midgut infection and virus dissemination were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR), while the presence and concentration of DENV in the saliva of infectious mosquitoes was determined by the focus forming assay. RESULTS: There were significant differences in the colonies' susceptibility to virus infection, dissemination, and transmission. All examined Ghanaian mosquitoes were refractory to infection by DENV serotype 2, while some colonies exhibited potential to transmit DENV serotype 1. None of the tested colonies were as competent as the control group colony. CONCLUSIONS: These findings give insight into the possible risk of outbreaks, particularly in the urban areas in the south of Ghana, and highlight the need for continuous surveillance to determine the transmission status and outbreak risk. This study also highlights the need to prevent importation of different DENV strains and potential invasion of new highly vector-competent Ae. aegypti strains, particularly around the ports of entry.

DOI： 10.1186/s13071-021-04728-z

Language：English   Publishing type：Research paper (scientific journal)  

Late male-killing, a male-specific death after hatching, is a unique phenotype found in <italic>Homona magnanima</italic>, oriental tea tortrix. The male-killing agent was suspected to be an RNA virus, but details were unknown. We herein successfully isolated and identified the putative male-killing virus as Osugoroshi viruses (OGVs). The three RNA-dependent RNA polymerase genes detected were phylogenetically related to Partitiviridae, a group of segmented double-stranded RNA viruses. Purified dsRNA from a late male-killing strain of <italic>H. magnanima</italic> revealed 24 segments, in addition to the RdRps, with consensus terminal sequences. These segments included the previously found male-killing agents MK1068 (herein OGV-related RNA16) and MK1241 (OGV-related RNA7) RNAs. Ultramicroscopic observation of purified virions, which induced late male-killing in the progeny of injected moths, showed sizes typical of Partitiviridae. Mathematical modeling showed the importance of late male-killing in facilitating horizontal transmission of OGVs in an <italic>H. magnanima</italic> population. This study is the first report on the isolation of partiti-like virus from insects, and one thought to be associated with late male-killing, although the viral genomic contents and combinations in each virus are still unknown.

DOI： 10.3389/fmicb.2020.620623

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Immunology  

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing a spread of coronavirus disease 2019 (COVID-19) globally. In order to end the COVID-19 pandemic, an effective vaccine against SARS-CoV-2 must be produced at low cost and disseminated worldwide. The spike (S) protein of coronaviruses plays a pivotal role in the infection to host cells. Therefore, targeting the S protein is one of the most rational approaches in developing vaccines and therapeutic agents. In this study, we optimized the expression of secreted trimerized S protein of SARS-CoV-2 using a silkworm-baculovirus expression vector system and evaluated its immunogenicity in mice. The results showed that the S protein forming the trimeric structure was the most stable when the chicken cartilage matrix protein was used as the trimeric motif and could be purified in large amounts from the serum of silkworm larvae. The purified S protein efficiently induced antigen-specific antibodies in mouse serum without adjuvant, but its ability to induce neutralizing antibodies was low. After examining several adjuvants, the use of Alum adjuvant was the most effective in inducing strong neutralizing antibody induction. We also examined the adjuvant effect of paramylon from Euglena gracilis when administered with the S protein. Our results highlight the effectiveness and suitable construct design of the S protein produced in silkworms for the subunit vaccine development against SARS-CoV-2.

DOI： 10.3389/fimmu.2021.803647

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Tough double network (DN) hydrogels are promising substitutes of soft supporting tissues such as cartilage and ligaments. For such applications, it is indispensable to robustly fix the hydrogels to bones with medically feasible methods. Recently, robustly bonding the DN hydrogels to defected bones of rabbits in vivo has been proved successful. The low crystalline hydroxyapatite (HAp) of calcium-phosphate-hydroxide salt coated on the surface layer of the DN hydrogels induced spontaneous osteogenesis penetrating into the semi-permeable hydrogels to form a gel/bone composite layer. In this work, the 44 Ca isotope-doped HAp/DN hydrogel is implanted in a defect of rabbit femoral bone and the dynamic osteogenesis process at the gel/bone interface is analyzed by tracing the calcium isotope ratio using isotope microscopy. The synthetic HAp hybridized on the surface layer of DN gel dissolves rapidly in the first two weeks by inflammation, and then the immature bone with a gradient structure starts to form in the gel region, reutilizing the dissolved Ca ions. These results reveal, for the first time, that synthetic HAp is reutilized for osteogenesis. These facts help to understand the lifetime of bone absorbable materials and to elucidate the mechanism of spontaneous, non-toxic, but strong fixation of hydrogels to bones.

DOI： 10.1002/adhm.202001731

Language：English   Publishing type：Research paper (scientific journal)  

In the case of a new viral disease outbreak, an immediate development of virus detection kits and vaccines is required. For COVID-19, we established a rapid production procedure for SARS-CoV-2 spike protein (S protein) by using the baculovirus-silkworm expression system. The baculovirus vector-derived S proteins were successfully secreted to silkworm serum, whereas those formed insoluble structure in the larval fat body and the pupal cells. The ectodomain of S protein with the native sequence was cleaved by the host furin-protease, resulting in less recombinant protein production. The S protein modified in furin protease-target site was efficiently secreted to silkworm serum and was purified as oligomers, which showed immunoreactivity for anti-SARS-CoV-2 S2 antibody. By using the direct transfection of recombinant bacmid to silkworms, we achieved the efficient production of SARS-CoV-2 S protein as fetal bovine serum (FBS)-free system. The resultant purified S protein would be useful tools for the development of immunodetection kits, antigen for immunization for immunoglobulin production, and vaccines.

DOI： 10.1016/j.bbrc.2020.06.020

Language：Others   Publishing type：Research paper (scientific journal)  

© 2020 Korean Society of Applied Entomology Recently, T7 Endonuclease I (T7E1) cleavage assay has been widely employed as an efficient approach for detecting mutations from CRISPR/Cas9 targeted samples. This enzyme is sufficient to detect single- and multiple-base mismatches from various heteroduplex DNA samples. However, T7E1 is quite expensive for researchers to use it only for screening mutations, especially in the condition of a large number of test samples. Regarding the production of this enzyme, to data, only the E. coli system has been reported and the highly overexpressed T7E1 seems toxic to the E. coli host cells. Thus, in this study, we tested whether the silkworm-baculovirus expression vector system (BEVS) is suitable to produce recombinant T7 Endonuclease I (rT7E1). The rT7E1 with N- or C-tags in cultured silkworm cells and silkworm pupae were successfully expressed. Our results demonstrated that the rT7E1-Ntag was highly expressed in silkworm pupae and we obtained rT7E1 proteins in high purity. Moreover, rT7E1 from silkworm-BEVS sufficiently recognized and cleaved the mismatches of designed and CRISPR/Cas9-mediated DNA substrates, which was equivalent to the commercial rT7E1 of the E. coli system. Taken together, our study would greatly support the genome-editing research by providing a cost-effective and active rT7E1 enzyme.

DOI： 10.1016/j.aspen.2020.05.001

Language：English   Publishing type：Research paper (scientific journal)  

Entomological surveillance is one of the tools used in monitoring and controlling vector-borne diseases. However, the use of entomological surveillance for arboviral infection vector control is often dependent on finding infected individuals. Although this method may suffice in highly endemic areas, it is not as effective in controlling the spread of diseases in low endemic and non-endemic areas. In this study, we examined the efficiency of using entomological markers to assess the status and risk of arbovirus infection in Ghana, which is considered a non-endemic country, by combining mosquito surveillance with virus isolation and detection. This study reports the presence of cryptic species of mosquitoes in Ghana, demonstrating the need to combine morphological identification and molecular techniques in mosquito surveillance. Furthermore, although no medically important viruses were detected, the importance of insect-specific viruses in understanding virus evolution and arbovirus transmission is discussed. This study reports the first mutualistic relationship between dengue virus and the double-stranded RNA Aedes aegypti totivirus. Finally, this study discusses the complexity of the virome of Aedes and Culex mosquitoes and its implication for arbovirus transmission.

DOI： 10.3390/v12020147

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Expression and Purification of Vaccinia Virus DNA Topoisomerase IB Produced in the Silkworm-Baculovirus Expression System.

DOI： 10.1007/s12033-019-00184-4

Language：English   Publishing type：Research paper (scientific journal)  

Human granulocyte-macrophage colony stimulating factor (hGM-CSF) is a hematopoietic growth factor. It is widely employed as a therapeutic agent targeting neutropenia in cancer patients undergoing chemotherapy and in patients with AIDS or after bone marrow transplantation. In this study, we constructed the recombinant baculoviruses for the expression of recombinant hGM-CSF (rhGM-CSF) with two small affinity tags (His-tag and Strep-tag) at the N or C-terminus. Compared to N-tagged rhGM-CSF, C-tagged rhGM-CSF was highly recovered from silkworm hemolymph. The purified rhGM-CSF proteins migrated as a diffuse band and were confirmed to hold N-glycosylations. A comparable activity was achieved when commercial hGM-CSF was tested as a control. Considering the high price of hGM-CSF in the market, our results and strategies using silkworm-baculovirus system can become a great reference for mass production of the active rhGM-CSF at a lower cost.

DOI： 10.1016/j.pep.2019.03.010

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Expression of the thermostable Moloney murine leukemia virus reverse transcriptase by silkworm-baculovirus expression system
© 2019 Korean Society of Applied Entomology Reverse transcriptase from Moloney murine leukemia virus (MMLVRT) is an RNA dependent DNA polymerase, which has been used as a fundamental tool for molecular biology and biotechnology. The secondary structures formed in the RNA templates decrease the accessibility of the reverse transcriptase to the RNA templates; it is important to unfold the RNA secondary structure by increasing the reaction temperature to perform the successful transcription. In this study, we applied silkworm baculovirus expression vector system (silkworm-BEVS) to mass-produce and purify the recombinant MMLVRTs with the N- or C- terminal tandem tags. We confirmed that both of the recombinant MMLVRT enzymes have intact DNA polymerase activity. It is notable that C- terminal tagged MMLVRT outperformed MMLVRT obtained from the E. coli expression system in terms of thermostability and sensitivity to low quantities of RNA template. Taken together, these results demonstrate that silkworm-BEVS is a promising alternative strategy to produce the functional and thermostable reverse transcriptase.

DOI： 10.1016/j.aspen.2019.02.008

Language：Others   Publishing type：Research paper (scientific journal)  

Expression, purification, and characterization of highly active endo-α-N-acetylgalactosaminidases expressed by silkworm-baculovirus expression system
© 2019 Korean Society of Applied Entomology The O-glycosidase, endo-α-N-acetylgalactosaminidase from Enterococcus faecalis (endoEF) catalyzes the cleavage of core 1 and core 3 type O-linked disaccharides between GalNAc and serine or threonine residues from glycoproteins. The endoEF has broad substrate specificity and thus is extensively utilized for the structural and functional analysis of the O-linked glycans. In this study, we expressed and purified the recombinant endoEF (rEndoEF) by using the silkworm-baculovirus expression vector system (Silkworm-BEVS) and confirmed the deglycosylation activity of rEndoEF targeting reporter glycoproteins, which was equivalent to the commercial O-glycosidase. Thus, our study provides important clues to produce highly active rEndoEF O-glycosidases employing silkworm-BEVS as an alternative.

DOI： 10.1016/j.aspen.2019.01.009

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In the growth kinetics analysis of flaviviruses in Aedes albopictus C6/36 cell lines obtained from the Japanese Collection of Research Bioresources (JCRB) Cell Bank and the European Collection of Authenticated Cell Culture (ECACC), these two cells line showed different viral susceptibility for Zika virus (ZIKV), Dengue virus (DENV), and Japanese encephalitis virus (JEV). Next-generation sequencing (NGS) analysis revealed that the C6/36 JCRB strain was persistently infected with two viruses without showing any cytopathic effects. The complete sequence analysis demonstrated that the one virus was Menghai rhabdovirus (MERV), which has been found from Aedes albopictus mosquito. The other virus was a novel virus, designated as Shinobi tetravirus (SHTV). Interestingly, the viral susceptibility of these two strains was almost even for Sindbis virus and Getah virus. We cloned SHTV and MERV from JCRB C6/36 cell line and then re-infected them into another C6/36 cell line, resulting in the reproduction of persistent infection with each virus. ZIKV growth was suppressed in SHTV and/or MERV re-infected C6/36 cells also. To our knowledge, this is the first demonstration that persistent infection with rhabdovirus and/or permutotetravirus suppressed flavivirus replication in mosquito cells.

DOI： 10.1016/j.heliyon.2018.e00736

Language：English   Publishing type：Research paper (scientific journal)  

In 2014 in Japan, 162 autochthonous dengue cases were reported for the first time in nearly 70 years. Here, we report the results of the detection and isolation of dengue virus (DENV) from mosquitoes collected in Tokyo Metropolis in 2014 and 2015. The phylogenetic relationship among DENV isolates from mosquitoes and from patients based on both the entire envelope gene and whole coding sequences was evaluated. Herein, 2,298 female and 956 male Aedes albopictus mosquitoes were collected at six suspected locations of DENV infection in Tokyo Metropolis from August to October in 2014 and grouped into 124 and 35 pools, respectively, for viral genome detection and DENV isolation. Dengue virus RNA was detected using reverse transcription polymerase chain reaction and TaqMan assays from 49 female pools; 16 isolates were obtained using C6/36 and Vero cells. High minimum infection rates (11.2-66.7) persisted until mid-September. All DENV isolates belonged to the genotype I in serotype 1 (DENV-1), and its sequences demonstrated > 99% homology to the sequence of the DENV isolated from a patient in the vicinity of Tokyo Metropolis in 2014. Therefore, Ae. albopictus was a major DENV vector, and a single DENV-1 strain circulated in Tokyo Metropolis in 2014. Dengue virus was not detected from male mosquitoes in 2014 and wild larvae in April 2015. Thus, the possibility of both vertical transmission and overwintering of DENV was extremely low, even in dengue-epidemic areas. This study reports the first entomological information on a dengue outbreak in a temperate region, where no Aedes aegypti mosquitoes are distributed.

DOI： 10.4269/ajtmh.17-0954

Language：English   Publishing type：Research paper (scientific journal)  

The genus Thogotovirus, as represented by Thogoto virus and Dhori virus, comprises a group of arthropod-borne viruses, most members of which are transmitted by ticks. Here we report the genetic and biological characterization of a new thogotovirus, designated Oz virus (OZV), isolated from the hard tick Amblyomma testudinarium in Ehime, Japan. OZV efficiently replicated and induced a cytopathic effect in Vero cells, from which enveloped pleomorphic virus particles were formed by budding. OZV could also replicate in BHK-21 and DH82 cells and caused high mortality in suckling mice after intracerebral inoculation. Phylogenetic analyses of six viral proteins indicated that OZV is clustered with Dhori and related viruses, and is most closely related in glycoprotein (GP) and matrix protein (M) sequences to Bourbon virus, a human-pathogenic thogotovirus discovered recently in the United States. Our findings emphasize the need for understanding the geographic distribution and ecology of OZV and related viruses and for reevaluation of the medical and public health importance of thogotoviruses.

DOI： 10.1016/j.virusres.2018.03.004

Language：English   Publishing type：Research paper (scientific journal)  

In Japan, indigenous tick-borne phleboviruses (TBPVs) and their associated diseases first became evident in 2013 by reported human cases of severe fever with thrombocytopenia syndrome (SFTS). In this study, we report a novel member of the genus Phlebovirus designated as Kabuto Mountain virus (KAMV), which was isolated from the ixodid tick Haemaphysalis flava in Hyogo, Japan. A complete viral genome sequencing and phylogenetic analyses showed that KAMV is a novel member of TBPVs, which is closely related to the Uukuniemi and Kaisodi group viruses. However, unlike the Uukuniemi group viruses, the 165-nt intergenic region (IGR) in the KAMV S segment was highly C-rich in the genomic sense and not predicted to form a secondary structure, which are rather similar to those of the Kaisodi group viruses and most mosquito/sandfly-borne phleboviruses. Furthermore, the NSs protein of KAMV was highly divergent from those of other TBPVs. These results provided further insights into the genetic diversity and evolutionary relationships of TBPVs. KAMV could infect and replicate in some rodent and primate cell lines. We evaluated the infectivity and pathogenicity of KAMV in suckling mice, where we obtained a virulent strain after two passages via intracerebral inoculation. This is the first report showing the existence of a previously unrecognized TBPV in Japan, other than the SFTS virus.

DOI： 10.1016/j.virusres.2017.11.030

Language：English   Publishing type：Research paper (scientific journal)  

During an entomological surveillance for arthropod-borne viruses in the Philippines, we isolated a previously unrecognized virus from female Armigeres spp. mosquitoes. Whole-genome sequencing, genetic characterization and phylogenetic analysis revealed that the isolated virus, designated Armigeres iflavirus (ArIFV), is a novel member of the iflaviruses (genus Iflavirus, family Iflaviridae) and phylogenetically related to Moku virus, Hubei odonate virus 4, slow bee paralysis virus and Graminella nigrifrons virus 1. To our knowledge, this is the first successful isolation of iflavirus from a dipteran insect. Spherical ArIFV particles of approximately 30 nm in diameter contained at least three major structural proteins. ArIFV multiplied to high titres (~109 p.f.u. ml-1) and formed clear plaques in a mosquito cell line, C6/36. Our findings provide new insights into the infection mechanism, genetic diversity and evolution of the Iflaviridae family.

DOI： 10.1099/jgv.0.000929

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.virusres.2017.11.030

Language：English   Publishing type：Research paper (scientific journal)  

During the course of tick-borne virus surveillance in Japan, three independent isolates of probably the same virus were obtained from three geographically distant populations of the hard tick Haemaphysalis flava. Genome analyses of the three isolates demonstrated that they were closely related but distinct strains of a novel virus, designated Tarumizu tick virus (TarTV), which has a genome of 12 double-stranded RNA segments. The development of the virus-induced cytopathic effects on BHK cells significantly varied according to virus strains. Ten out of 12 segments of TarTV appeared to encode putative orthologs or functional equivalents of viral proteins of Colorado tick fever virus (CTFV) and Eyach virus, suggesting that TarTV is the third member of the genus Coltivirus in the family Reoviridae. This was supported by the facts that the 5'- and 3'-terminal consensus sequences of coltivirus genomes were found also in TarTV genome, and segment 9 of TarTV had sequence and structural features that may mediate a stop codon read-through as observed in that of CTFV. However, segment 7 and 10 of TarTV had no significant sequence similarities to any other proteins of known coltiviruses. Electron microscopic analysis demonstrated that TarTV particle had a non-enveloped bilayer icosahedral structure, and viral inclusion bodies were formed in infected cells. TarTV could infect and replicate in several mammalian cell lines tested, but show no clinical symptoms in intracerebrally inoculated mice. Taken together, our findings provide new insights into genetic diversity and evolution of the genus Coltivirus.

DOI： 10.1016/j.virusres.2017.09.017

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1099/jgv.0.000929

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.virusres.2017.09.017

Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

Language：English   Publishing type：Research paper (scientific journal)  

We isolated two distinct viruses from mosquitoes collected in Bustos, Bulacan province, Philippines, in 2009. These viruses show rapid replication and strong cytopathic effects in mosquito C6/36 cells. Whole-genome analysis of these viruses demonstrated that both viruses belong to the negevirus group. One of the viruses, from Culex vishunui mosquitoes, is a new strain of Negev virus. The other virus, from a Mansonia sp. mosquito, is a new negevirus designated Bustos virus. Gene expression analysis of the Bustos virus revealed that infected cells contain viral subgenomic RNAs that probably include open reading frame (ORF) 2 or ORF3. Purified Bustos virus particles contained at least three proteins, and the major component (a probable major capsid protein) is encoded by ORF3. Bustos virus did not show infectivity in mammalian BHK-21 cells, suggesting that it is an insect-specific virus, like other known negeviruses.

DOI： 10.1007/s00705-016-3068-4

Language：English   Publishing type：Research paper (scientific journal)  

Background and objectives
Mechanism of regeneration of remnant pancreas after partial pancreatectomy (PX) is still unknown. In this study, effect of siRNA against the collagen specific chaperone, HSP47, which inhibits collagen secretion from activated pancreas stellate cells (aPSCs), and induces their apoptosis, on regeneration of remnant pancreas was determined.
Methods
Pancreatectomy was performed according to established methods. Proliferation of cells was assessed by BrdU incorporation. Immunostaining of HSP47 was employed to identify PSCs. Progenitor cells were identified by SOX9 staining. Acinar cells were immunostained for amylase. Co-culture of acinar cells with aPSCs were carried out in a double chamber with a cell culture insert. siRNA HSP47 encapsulated in vitamin A-coupled liposome (VA-lip siRNA HSP47) was delivered to aPSCs by iv injection.
Results
In remnant pancreas of 90% PX rat, new areas of foci were located separately from duodenal areas with normal pancreatic features. After PX, BrdU uptake of acinar cells and islet cells significantly increased, but was suppressed by treatment with VA-lip siRNA HSP47. BrdU uptake by acinar cells was augmented by co-culturing with aPSCs and the augmentation was nullified by siRNA HSP47. BrdU uptake by progenitor cells in foci area was slightly enhanced by the same treatment. New area which exhibited intermediate features between those of duodenal and area of foci, emerged after the treatment.
Conclusion
aPSCs play a crucial role in regeneration of remnant pancreas, proliferation of acinar and islet cells after PX through the activity of secreted collagen. Characterization of new area emerged by siRNA HSP47 treatment as to its origin is a future task.

DOI： 10.1371/journal.pone.0165747

Language：English   Publishing type：Research paper (other academic)  

Characterization of Bustos virus, a new member of the Negevirus group isolated from Mansonia mosquito in the Phillippines

Language：English  

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

We isolated and characterized a novel positive-sense, single-stranded RNA virus from Aedes larvae collected on Okushiri Island, Hokkaido, Japan. This virus, designated Okushiri virus (OKV), replicated in the Aedes albopictus cell line C6/36 with severe cytopathic effects and produced a large number of spherical viral particles that were 50-70 nm in diameter and released into the cell culture medium. The OKV genome consisted of 9,704 nucleotides, excluding the poly(A) tail at the 3'-terminus, and contained three major open reading frames (ORF1, ORF2, and ORF3). ORF1 encoded a putative protein of approximately 268 kDa that included a methyltransferase domain, FtsJ-like methyltransferase domain, helicase domain, and RNA-dependent RNA polymerase domain. The genome organization and results of a phylogenetic analysis based on the amino acid sequence predicted from the nucleotide sequence indicated that OKV is a member of a new insect virus group of negeviruses with a possible evolutionary relationship to some plant viruses. ORF2 and ORF3 were suggested to encode hypothetical membrane-associated proteins of approximately 45 kDa and 22 kDa, respectively. This is the first study on a novel negevirus isolated from mosquito larvae in Japan.

DOI： 10.1007/s00705-015-2711-9

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

The Bombyx mori nucleopolyhedrovirus (BmNPV) ie-1 promoter exhibits strong transcriptional activity and is used in transient foreign gene expression systems in insect cells. In a reporter assay experiment using the BmNPV ie-1 promoter, we found that it exhibited activity even in non-host mammalian BHK cells, plant BY-2 cells, and also bacterial Escherichia coli cells. An analysis using a deletion series of the BmNPV ie-1 promoter demonstrated that the core promoter region of this promoter was sufficient to display promoter activity in BHK cells, BY-2 cells, and E. coli cells, whereas upstream elements were required for higher activity in insect cells. Furthermore, we found that the BmNPV ie-1 promoter exhibited sufficient activity for a beta-galactosidase assay in E. coil cells. The results obtained here suggest that the BmNPV ie-1 promoter has potential as a universal promoter for transient expression systems in insect, mammalian, plant, and bacterial cells. (C) 2015 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2015.07.126

Language：English   Publishing type：Research paper (scientific journal)  

Stellate cells are distributed throughout organs, where, upon chronic damage, they become activated and proliferate to secrete collagen, which results in organ fibrosis. An intriguing property of hepatic stellate cells (HSCs) is that they undergo apoptosis when collagen is resolved by stopping tissue damage or by treatment, even though the mechanisms are unknown. Here we disclose the fact that HSCs, normal diploid cells, acquired dependence on collagen for their growth during the transition from quiescent to active states. The intramolecular RGD motifs of collagen were exposed by cleavage with their own membrane type 1 matrix metalloproteinase (MT1-MMP). The following evidence supports this conclusion. When rat activated HSCs (aHSCs) were transduced with siRNA against the collagen-specific chaperone gp46 to inhibit collagen secretion, the cells underwent autophagy followed by apoptosis. Concomitantly, the growth of aHSCs was suppressed, whereas that of quiescent HSCs was not. These in vitro results are compatible with the in vivo observation that apoptosis of aHSCs was induced in cirrhotic livers of rats treated with siRNAgp46. siRNA against MT1-MMP and addition of tissue inhibitor of metalloproteinase 2 (TIMP-2), which mainly inhibits MT1-MMP, also significantly suppressed the growth of aHSCs in vitro. The RGD inhibitors echistatin and GRGDS peptide and siRNA against the RGD receptor alpha V beta 1 resulted in the inhibition of aHSCs growth. Transduction of siRNAs against gp46, alpha V beta 1, and MT1-MMP to aHSCs inhibited the survival signal of PI3K/AKT/I kappa B. These results could provide novel antifibrosis strategies.

DOI： 10.1074/jbc.M113.544494

Language：English   Publishing type：Research paper (scientific journal)  

Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes located between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells. © 2013 Elsevier Inc.

DOI： 10.1016/j.bbrc.2013.08.037

Language：English   Publishing type：Research paper (scientific journal)  

Background and objective
Fibrosis associated with chronic pancreatitis is an irreversible lesion that can disrupt pancreatic exocrine and endocrine function. Currently, there are no approved treatments for this disease. We previously showed that siRNA against collagen-specific chaperone protein gp46, encapsulated in vitamin A-coupled liposomes (VA-lip-siRNAgp46), resolved fibrosis in a model of liver cirrhosis. This treatment was investigated for pancreatic fibrosis induced by dibutyltin dichloride (DBTC) and cerulein in rats.
Methods
Specific uptake of VA-lip-siRNAgp46, conjugated with 6-carboxyfluorescein (FAM) by activated pancreatic stellate cells (aPSCs), was analysed by fluorescence activated cell sorting (FACS). Intracellular distribution of VA-lip-siRNAgp46-FAM was examined by fluorescent microscopy. Suppression of gp46 expression by VA-lip-siRNAgp46 was assessed by immunoblotting. Collagen synthesis in aPSCs was assayed by dye-binding. Specific delivery of VA-lip-siRNAgp46 to aPSCs in DBTC rats was verified following intravenous VA-lip-siRNA-FAM and H-3-VA-lip-siRNAgp46. The effect of VA-lip-siRNA on pancreatic histology in DBTC- and cerulein-treated rats was determined by Azan-Mallory staining and hydroxyproline content.
Results
FACS analysis revealed specific uptake of VA-lip-siRNAgp46-FAM through the retinol binding protein receptor by aPSCs in vitro. Immunoblotting and collagen assay verified knockdown of gp46 and suppression of collagen secretion, respectively, by aPSCs after transduction of VA-lip-siRNAgp46. Specific delivery of VA-lip-siRNAgp46 to aPSCs in fibrotic areas in DBTC rats was confirmed by fluorescence and radioactivity 24h after the final injection. 10 systemic VA-lip-siRNAgp46 treatments resolved pancreatic fibrosis, and suppressed tissue hydroxyproline levels in DBTC- and cerulein-treated rats.
Conclusion
These data suggest the therapeutic potential of the present approach for reversing pancreatic fibrosis.

DOI： 10.1136/gutjnl-2011-301746

Language：English   Publishing type：Research paper (scientific journal)  

The baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is used as a safer viral vector in mammalian cells with potential applications in gene therapy. However, the mechanism for the insusceptibility of mammalian cells to proliferative infection by entomopathogenic viruses is not well understood. Here, we studied the significance of epigenetic modifications such as histone acetylation, histone methylation and HP1 accumulation for AcMNPV gene expression in mammalian BHK cells. Real-time PCR and chromatin immunoprecipitation with sodium butyrate revealed an important relationship between viral gene expression and histone acetylation, with implications for a mechanism of suppression of AcMNPV gene expression in BHK cells.

DOI： 10.1007/s00705-010-0614-3

Language：English   Publishing type：Research paper (scientific journal)  

Use of Bombyx mori U6 Promoter for Inducing Gene-Silencing in Silkworm Cells

DOI： 10.11416/jibs.77.3_125

Language：English   Publishing type：Research paper (other academic)  

Supression of AcMNPV gene expression in mammalian cells

Language：English   Publishing type：Research paper (other academic)  

Restricted gene transcription of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in mammalian cells

Language：English   Publishing type：Research paper (scientific journal)  

Marked decrease of ribosomal RNA in BmN cells infected with AcMNPV

DOI： 10.11416/jibs.74.125

Language：English   Publishing type：Research paper (scientific journal)  

The gene expression of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) was examined in two types of mammalian cells, human HeLa14 and hamster BHK cells. DNA microarray analysis followed by reverse transcription-PCR identified at least 12 viral genes transcribed in both HeLa14 cells and BHK cells inoculated with AcMNPV. 5' rapid amplification of cDNA ends was carried out to examine the transcriptional fidelity of these genes in HeLa14 cells. The transcription of ie-1, ie-0 and gp64 was initiated at a baculovirus early gene motif, CAGT, accompanied by a TATA motif. In addition, the same splicing observed for ie-0 mRNA in Sf9 cells occurred in HeLa14 cells. While the transcription initiation sites for pe38 and p6.9 were not located in the CAGT motif, most of them were in a typical eukaryotic RNA polymerase II promoter structure (a conventional TATA motif and/or an initiator). Interestingly, the expression of beta-actin was upregulated in the mammalian cells inoculated with AcMNPV. Subsequent experiments using UV-inactivated virus confirmed the upregulation, suggesting that de novo synthesis of viral products is not required for the event. These results indicated that the AcMNPV genome acts as a template for transcription in mammalian cells through the usual infection pathway, though there is no evidence for the functional expression of viral genes at present.

DOI： 10.1128/JVI.80.5.2390-2395.2006

Language：English   Publishing type：Research paper (scientific journal)  

We happened to discover that the cauliflower mosaic virus (CaMV) 35S promoter inserted into a recombinant Autographa californica multicapsid nucleopolyhedrovirus (rAcMNPV) was strongly activated during the replication of the recombinant virus in Spodoptera frugiperda (Sf9) cells. The expression of the luciferase gene from the 35S promoter in rAcMNPV was remarkably increased late in infection and was resistant to alpha-amanitin treatment. Primer extension indicated that transcriptional initiation from the 35S promoter in Sf9 cells occurred within one of the two baculoviral late promoter TAAG motifs located in the vicinity of the transcription start site in plant cells. These observations suggested that the CaMV 35S promoter served as a transcription start site for AcMNPV-induced RNA polymerase. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.virusres.2005.03.019

Language：Japanese  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：産業医科大学 6号館   Country：Japan  

九州大学伊都キャンパスはおよそ10年前に福岡市西区の山中に造成され, 現在もキャンパス敷地の半分ほどが生物多様性保全ゾーンとして植生が保存されている. この保全ゾーンではイノシシやタヌキ, アナグマなどの動物が多く活動しており, 住宅街と生物環境が大きく異なっている. このような生物環境の違いが蚊の生態系および蚊が保有しているウイルス叢にどのような影響を与えているのかを調査する目的で, 蚊の経時的な捕集調査とウイルスのメタゲノム解析を実施した. 比較対象としては九州大学と同じ福岡市西区にある住宅街の神社を設定した. 2020年および2021年の2カ年における調査の結果, 蚊の捕集数は神社の方が大学キャンパスよりも10倍ほど多いこと, また蚊成虫の発生ピークは両年とも9月末頃であることが明らかとなった. いずれの地点でも最頻種はヒトスジシマカであったが, 大学キャンパスの方が多種の割合が高いという結果も得られた.
　捕集蚊を採集月, および種毎に分別し, 1–25頭ずつを1プールとしたサンプルからRNA抽出を行い, 次世代シーケンサーを用いたウイルスの網羅的解析を実施した. 2,089個体149プールのサンプル解析の結果, 西区の蚊にはShinobi tetravirusやWhenzhou sobemo-like virus 4などのウイルスを保有していることが明らかとなった. 今後はウイルスの保有宿主の同定や2022年以降のウイルス発生動向などについて調査をする予定である.

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：岩手大学 (オンライン)   Country：Japan  

Event date： 2023.10 - 2024.10

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：北九州国際会議場 (北九州市)   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：九州大学伊都キャンパス   Country：Japan  

Event date： 2023.7

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2023.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立国際料研究センター　国立感染症研究所   Country：Japan  

自然界には未同定のものも含め、夥しい数のウイルスが存在しており、またその多くは病原性を有さない形で宿主と共存している。しかし、どのようなウイルスがどの地域で、どの程度の感染をしているかについてはほとんど明らかになっていない。本研究では、九州大学伊都キャンパス周辺の福岡市西区における蚊のウイルス叢を解明することを目的として、蚊の捕集による季節消長の調査と、捕集蚊におけるウイルス叢解析を行った。2020–2021年の2カ年の結果では、当該地域市街地における優占種はヒトスジシマカであり、発生ピークは両年とも9月下旬であった。2カ年で捕集した計13種、2,089個体の蚊から次世代シーケンサーを用いた網羅的ウイルス解析を行った結果、福岡市西区某神社のヒトスジシマカから高頻度にShinobi tetravirusが検出された。Shinobi tetravirusは培養細胞において、デングウイルス等のアルボウイルスに対して感染抑制機能を持っており、このような機能を持つウイルスが野外蚊から見いだされたことから、野外集団におけるウイルス叢が蚊のウイルス媒介能に何らかの影響を与えていることが予想される。他にも、今回の調査対象蚊からは植物ウイルスと類縁性のあるWenzhou sobemovirusの他、未同定のウイルス様配列が複数検出された。このように、福岡市の蚊には他地域で既に検出・同定されているウイルスが見られただけでなく、未同定新規ウイルスが存在していることが示唆された。

Event date： 2023.4

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：国立国際料研究センター　国立感染症研究所   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学 共同獣医学研究科棟 大講義室   Country：Japan  

【はじめに】
ダビーバンダウイルス (SFTSウイルス) を始め, マダニは様々な病原ウイルスを媒介することで知られている. その中には新規ウイルスも含まれ, ヒト等への感染性が疑われるジンメンダニウイルス (Jingmen tick virus) が新たにマダニ媒介性ウイルスとして見つかった. その後, 類縁のウイルスが次々と見つかり, 現在はジンメンウイルスグループとしてひとつの分類群を形成していることが明らかとなった. 本講演ではジンメンウイルスの国内発見事例の紹介と, 近年の動向について概説する.
【方法】
国内各地で動物咬着マダニあるいは植生マダニを捕集し, その破砕液に含まれるウイルスの同定をNGS法で実施した. 得られたウイルス配列については海外のウイルスゲノム配列と合わせて比較解析を実施した. また一部のサンプルについては動物由来培養細胞を用いたウイルス分離試験を実施するとともに, ウイルス培養系の独自手法の開発を実施した.
【結果】
国内4地点で捕集されたタカサゴキララマダニからJingmen tick virusが, 1地点のヤマアラシチマダニから近縁のTakachi virusが新たに検出・同定された. Jingmen tick virusには遺伝学的に分別可能な複数の株が存在し, これらは中国での検出サンプルとそれぞれ類似性を示していた. またTakachi virusはJingmen tick virusとアミノ酸配列 (RdRp) で80%程度の相同性を有しており, Alongshan virus同様, ジンメンウイルスグループを構成する別種ウイルスであることが示された. Jingmen tick virusは難培養性であり, 一般的な方法では3継代程度で消失するが, 感染細胞自身を含めた形で継代を繰り返すことで, 細胞傷害性を維持したまま継代可能であることが明らかとなった.
【結論】
ジンメンウイルスは新興のマダニ感染症病原体と考えられ, アジアならびに世界に分布していることから, 今後国内の分布調査や海外からの移出入について注意が必要である.

Event date： 2022.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：京都産業大学むすびわざ館   Country：Japan  

ウイルスは宿主細胞の装置を利用して増殖するため、宿主生物の進化と多様化に伴って自 身も適応進化を遂げてきた。その結果、現存するウイルスの多くは特定の生物およびその近 縁種に限定された宿主域を示すが、例外となるのが昆虫媒介性ウイルス (アルボウイルス) である。これまでに確認されているアルボウイルスはアフリカ豚コレラウイルス 1 種を除き、 全て RNA ウイルスであり、DNA ウイルスでは特にこの宿主域制限が厳しいようである。宿主 域を決定するプロセスはいくつかあるが、特に重要となるのが細胞への侵入プロセスと、感 染細胞におけるウイルス増殖の 2 つである。本談話会ではこの 2 点についてそれぞれ、これ までの研究成果とともに、ウイルスの宿主域変化の際にどのような壁があるのかについて議 論させて頂く。
1 点目は無脊椎動物・脊椎動物の両細胞に侵入可能であるものの、無脊椎動物でしか増殖 できないバキュロウイルスを例にとり、RNA ウイルスにはない「DNA-RNA 転写」プロセスにお ける機能的制限について議論する。2 点目として、オルソミクソウイルス科の中で唯一無脊 椎動物への感染性を示すトゴトウイルス属について、その膜タンパク質の進化と昆虫ウイル スの膜タンパク質との類似性について紹介し、脊椎動物病原性ウイルスのアルボウイルス化 の可能性について議論したい。

Event date： 2022.2 - 2023.2

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

昆虫類は実に多様なウイルスを保有しており、その大半は病原性を示さないと考えられている。一方、中には宿主昆虫や他の生物種に対して病原性を示すものもあり、特に人獣に媒介されて感染症を引き起こすものはアルボウイルスと呼ばれている。デングウイルスなどのアルボウイルスは進化的には昆虫特異的なウイルスから派生してきたと考えられているが、そもそもどのような昆虫ウイルスがいるのかについてはほとんど明らかにされていない。特に感染症研究は熱帯・亜熱帯地域を中心に行われており、寒冷地域での知見は特に乏しい。そこで、寒冷地域に生息する蚊がどのようなウイルスを保有しているのかを調べるべく、北海道石狩市で北方系ヤブカ類の捕集と、捕集個体からのウイルス分離を行った。2018年の捕集調査ではアカンヤブカ、チシマヤブカ、トカチヤブカ、スジアシイエカが計23個体得られた。捕集蚊のRNAおよび培養細胞でウイルス培養を行ったサンプルのNGS解析の結果、24種のウイルス様配列が検出され、9種が培養系で分離された。また、これらのうち16種は新規ウイルスであった。得られたウイルスの中には既知ウイルス分類群と類縁性を示さないものや、植物ウイルスとの関連を示すものなど、他に見られない特徴が多く見られ、北方系ヤブカ類のもつウイルス多様性の一端が示された。

Event date： 2020.6

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：九州大学 ジョナサン・KS・チョイ文化館   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：マリンメッセ福岡   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：マリンメッセ福岡   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：マリンメッセ福岡   Country：Japan  

Event date： 2019.6 - 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京農工大学小金井キャンパス   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京農工大学小金井キャンパス   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京農工大学小金井キャンパス   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：富士calm (山梨県富士吉田市)   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Language：Japanese  

Language：Japanese  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese  

Language：Japanese  

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Language：Japanese  

Language：English   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

How to overcome the issues related to medical insects

Language：Japanese  

愛媛県で捕集されたマダニから分離された新規トゴトウイルスの性状解析

Language：Japanese  

ツシマヤマネコ咬着タカサゴキララマダニからのJingmen tick virusの分離

Language：Japanese  

愛媛県で捕集されたマダニから分離された新規トゴトウイルスの性状解析

Language：Japanese  

Language：Japanese  

2016年および2017年のベトナムにおける蚊のウイルス叢調査

Language：Japanese  

ガーナ産マダニからのマダニ媒介ウイルス遺伝子の検出

Language：Japanese  

キチマダニより分離された新規レオウイルス科ウイルスであるTarumizu tick virusの性状解析

Language：Japanese  

Language：Japanese  

死亡タヌキの脳より分離された新規コロラドダニ熱ウイルス

Language：Japanese  

神奈川県厚木市で採集されたマダニと吸血源動物との関係解析

Language：Japanese  

ベトナムのヤブカより分離されたウイルスに関する解析

Language：Japanese  

2016年ガーナ共和国における疾病媒介節足動物の分布調査ならびに保有ウイルスの解析

Language：English  

Characterization of Bustos virus, a new member of the Negevirus group isolated from Mansonia mosquito in the Phillippines

Language：Japanese  

Language：Japanese  

次世代シーケンサーを用いた吸血性節足動物保有ウイルスの迅速・網羅的な同定

Language：Japanese  

重症熱性血小板減少症候群(SFTS)の患者発生地で採集されたフタトゲチマダニの吸血源動物の特定

Language：English  

Language：Japanese  

Language：English  

Supression of AcMNPV gene expression in mammalian cells

Language：English  

Restricted gene transcription of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in mammalian cells

Language：Japanese  

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Number of peer-reviewed articles in Japanese journals：0

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Competition, symposium, etc. 

Number of participants：70

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：5

Type：Competition, symposium, etc. 

Number of participants：104

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

NHKニュース845において、マダニが媒介する感染症に関する注意喚起と解説を行った。

ロクイチ福岡の特集、「ウイルスの“運び屋”を追え! 鳥インフルエンザ研究最前線」において媒介感染症研究の現状を紹介した。

高病原性鳥インフルエンザとハエに関する研究内容が紹介された

高病原性鳥インフルエンザとハエの関係に関する研究について、田村貴昭衆議院議員と会談を行い、その様子が記事となった。

高病原性鳥インフルエンザとハエの関係についての研究について、「サイエンスReport」特集において解説記事が掲載された。

特集記事「昆虫フロンティア」において、衛生昆虫学研究室で実施している鳥インフル媒介説や新規ウイルスの研究に関する記事が掲載された。

12/28、鹿児島県出水市における鳥インフルエンザとハエの関連について調査した研究内容が紹介された。

12/28、鳥インフルエンザとハエの関連について調査した研究内容が紹介された。
同記事の掲載先は「北海道新聞デジタル」、「西日本新聞me」、「新潟日報デジタルプラス」、「沖縄タイムス＋プラス」、「埼玉新聞」、「千葉日報」、「ニッポンドットコム」、「北日本新聞webunプラス」、「高知新聞」、「山形新聞」など。

NHK「ロクいち！福岡」において、秋以降の蚊の発生状況や温暖化による影響、輸入感染症に関する注意喚起等について紹介した。

12/26 12:15からの九州・沖縄のニュースにおいて、鳥インフルエンザとハエの関連について調査した研究内容が紹介された。

12/26 13時からの列島ニュースにおいて、鳥インフルエンザとハエの関連について調査した研究内容が紹介された。

12/26、ニュース記事としてヨテミラで、鳥インフルエンザとハエの関連について調査した研究内容が紹介された。

12/26、RKBオンラインニュースで、鳥インフルエンザとハエの関連について調査した研究内容が紹介された。

夕方情報番組「ただいま！」にて、注意すべき夏の虫と題して、マダニや蚊の情報についての解説を行った。

NHK「ロクいち！福岡」において、アウトドアや子どもの外遊びの際に注意すべきマダニについて、その生息場所の調査内容や関連する感染症に関して紹介・解説した。

2021年TBS年末特番「報道の日」において、コロナ禍でさらに注目が増している新規ウイルスに関する研究について、昆虫媒介ウイルス研究の取り組み例を紹介しました。