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Yasuko Orba
International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan

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Journal article
Published: 24 August 2021 in Viruses
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The interaction of viral nucleic acid with protein factors is a crucial process for initiating viral polymerase-mediated viral genome replication while activating pattern recognition receptor (PRR)-mediated innate immune responses. It has previously been reported that a hydrolysate of Ge-132, 3-(trihydroxygermyl) propanoic acid (THGP), shows a modulatory effect on microbial infections, inflammation, and immune responses. However, the detailed mechanism by which THGP can modify these processes during viral infections remained unknown. Here, we show that THGP can specifically downregulate type I interferon (IFN) production in response to stimulation with a cytosolic RNA sensor RIG-I ligand 5′-triphosphate RNA (3pRNA) but not double-stranded RNA, DNA, or lipopolysaccharide. Consistently, treatment with THGP resulted in the dose-dependent suppression of type I IFN induction upon infections with influenza virus (IAV) and vesicular stomatitis virus, which are known to be mainly sensed by RIG-I. Mechanistically, THGP directly binds to the 5′-triphosphate moiety of viral RNA and competes with RIG-I-mediated recognition. Furthermore, we found that THGP can directly counteract the replication of IAV but not EMCV (encephalitismyocarditis virus), by inhibiting the interaction of viral polymerase with RNA genome. Finally, IAV RNA levels were significantly reduced in the lung tissues of THGP-treated mice when compared with untreated mice. These results suggest a possible therapeutic implication of THGP and show direct antiviral action, together with the suppressive activity of innate inflammation.

ACS Style

Sunanda Baidya; Yoko Nishimoto; Seiichi Sato; Yasuhiro Shimada; Nozomi Sakurai; Hirotaka Nonaka; Koki Noguchi; Mizuki Kido; Satoshi Tadano; Kozo Ishikawa; Kai Li; Aoi Okubo; Taisho Yamada; Yasuko Orba; Michihito Sasaki; Hirofumi Sawa; Hiroko Miyamoto; Ayato Takada; Takashi Nakamura; Akinori Takaoka. Dual Effect of Organogermanium Compound THGP on RIG-I-Mediated Viral Sensing and Viral Replication during Influenza a Virus Infection. Viruses 2021, 13, 1674 .

AMA Style

Sunanda Baidya, Yoko Nishimoto, Seiichi Sato, Yasuhiro Shimada, Nozomi Sakurai, Hirotaka Nonaka, Koki Noguchi, Mizuki Kido, Satoshi Tadano, Kozo Ishikawa, Kai Li, Aoi Okubo, Taisho Yamada, Yasuko Orba, Michihito Sasaki, Hirofumi Sawa, Hiroko Miyamoto, Ayato Takada, Takashi Nakamura, Akinori Takaoka. Dual Effect of Organogermanium Compound THGP on RIG-I-Mediated Viral Sensing and Viral Replication during Influenza a Virus Infection. Viruses. 2021; 13 (9):1674.

Chicago/Turabian Style

Sunanda Baidya; Yoko Nishimoto; Seiichi Sato; Yasuhiro Shimada; Nozomi Sakurai; Hirotaka Nonaka; Koki Noguchi; Mizuki Kido; Satoshi Tadano; Kozo Ishikawa; Kai Li; Aoi Okubo; Taisho Yamada; Yasuko Orba; Michihito Sasaki; Hirofumi Sawa; Hiroko Miyamoto; Ayato Takada; Takashi Nakamura; Akinori Takaoka. 2021. "Dual Effect of Organogermanium Compound THGP on RIG-I-Mediated Viral Sensing and Viral Replication during Influenza a Virus Infection." Viruses 13, no. 9: 1674.

Review
Published: 10 August 2021 in Pathogens
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Emerging and re-emerging mosquito-borne viral diseases are a threat to global health. This systematic review aimed to investigate the available evidence of mosquito-borne viral pathogens reported in Zambia. A search of literature was conducted in PubMed and Google Scholar for articles published from 1 January 1930 to 30 June 2020 using a combination of keywords. Eight mosquito-borne viruses belonging to three families, Togaviridae, Flaviviridae and Phenuiviridae were reported. Three viruses (Chikungunya virus, Mayaro virus, Mwinilunga virus) were reported among the togaviruses whilst four (dengue virus, West Nile virus, yellow fever virus, Zika virus) were among the flavivirus and only one virus, Rift Valley fever virus, was reported in the Phenuiviridae family. The majority of these mosquito-borne viruses were reported in Western and North-Western provinces. Aedes and Culex species were the main mosquito-borne viral vectors reported. Farming, fishing, movement of people and rain patterns were among factors associated with mosquito-borne viral infection in Zambia. Better diagnostic methods, such as the use of molecular tools, to detect the viruses in potential vectors, humans, and animals, including the recognition of arboviral risk zones and how the viruses circulate, are important for improved surveillance and design of effective prevention and control measures.

ACS Style

Rachel Milomba Velu; Geoffrey Kwenda; Liyali Libonda; Caroline Cleopatra Chisenga; Bumbangi Nsoni Flavien; Obvious Nchimunya Chilyabanyama; Michelo Simunyandi; Samuel Bosomprah; Nicholus Chintu Sande; Katendi Changula; Walter Muleya; Monicah Mirai Mburu; Benjamin Mubemba; Simbarashe Chitanga; John Tembo; Matthew Bates; Nathan Kapata; Yasuko Orba; Masahiro Kajihara; Ayato Takada; Hirofumi Sawa; Roma Chilengi; Edgar Simulundu. Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review. Pathogens 2021, 10, 1007 .

AMA Style

Rachel Milomba Velu, Geoffrey Kwenda, Liyali Libonda, Caroline Cleopatra Chisenga, Bumbangi Nsoni Flavien, Obvious Nchimunya Chilyabanyama, Michelo Simunyandi, Samuel Bosomprah, Nicholus Chintu Sande, Katendi Changula, Walter Muleya, Monicah Mirai Mburu, Benjamin Mubemba, Simbarashe Chitanga, John Tembo, Matthew Bates, Nathan Kapata, Yasuko Orba, Masahiro Kajihara, Ayato Takada, Hirofumi Sawa, Roma Chilengi, Edgar Simulundu. Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review. Pathogens. 2021; 10 (8):1007.

Chicago/Turabian Style

Rachel Milomba Velu; Geoffrey Kwenda; Liyali Libonda; Caroline Cleopatra Chisenga; Bumbangi Nsoni Flavien; Obvious Nchimunya Chilyabanyama; Michelo Simunyandi; Samuel Bosomprah; Nicholus Chintu Sande; Katendi Changula; Walter Muleya; Monicah Mirai Mburu; Benjamin Mubemba; Simbarashe Chitanga; John Tembo; Matthew Bates; Nathan Kapata; Yasuko Orba; Masahiro Kajihara; Ayato Takada; Hirofumi Sawa; Roma Chilengi; Edgar Simulundu. 2021. "Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review." Pathogens 10, no. 8: 1007.

Infectious diseases
Published: 01 June 2021 in PLOS Neglected Tropical Diseases
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Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis with a high case fatality rate in humans. Although the disease is widely found in Africa, Europe, and Asia, the distribution and genetic diversity of CCHF virus (CCHFV) are poorly understood in African countries. To assess the risks of CCHF in Zambia, where CCHF has never been reported, epidemiologic studies in cattle and ticks were conducted. Through an indirect immunofluorescence assay, CCHFV nucleoprotein-specific serum IgG was detected in 8.4% (88/1,047) of cattle. Among 290 Hyalomma ticks, the principal vector of CCHFV, the viral genome was detected in 11 ticks. Phylogenetic analyses of the CCHFV S and M genome segments revealed that one of the detected viruses was a genetic reassortant between African and Asian strains. This study provides compelling evidence for the presence of CCHFV in Zambia and its transmission to vertebrate hosts.

ACS Style

Masahiro Kajihara; Martin Simuunza; Ngonda Saasa; George Dautu; Akina Mori-Kajihara; Yongjin Qiu; Ryo Nakao; Yoshiki Eto; Hayato Furumoto; Bernard M. Hang’Ombe; Yasuko Orba; Hirofumi Sawa; Edgar Simulundu; Shuetsu Fukushi; Shigeru Morikawa; Masayuki Saijo; Jiro Arikawa; Swithine Kabilika; Mwaka Monze; Victor Mukonka; Aaron Mweene; Ayato Takada; Kumiko Yoshimatsu. Serologic and molecular evidence for circulation of Crimean-Congo hemorrhagic fever virus in ticks and cattle in Zambia. PLOS Neglected Tropical Diseases 2021, 15, e0009452 .

AMA Style

Masahiro Kajihara, Martin Simuunza, Ngonda Saasa, George Dautu, Akina Mori-Kajihara, Yongjin Qiu, Ryo Nakao, Yoshiki Eto, Hayato Furumoto, Bernard M. Hang’Ombe, Yasuko Orba, Hirofumi Sawa, Edgar Simulundu, Shuetsu Fukushi, Shigeru Morikawa, Masayuki Saijo, Jiro Arikawa, Swithine Kabilika, Mwaka Monze, Victor Mukonka, Aaron Mweene, Ayato Takada, Kumiko Yoshimatsu. Serologic and molecular evidence for circulation of Crimean-Congo hemorrhagic fever virus in ticks and cattle in Zambia. PLOS Neglected Tropical Diseases. 2021; 15 (6):e0009452.

Chicago/Turabian Style

Masahiro Kajihara; Martin Simuunza; Ngonda Saasa; George Dautu; Akina Mori-Kajihara; Yongjin Qiu; Ryo Nakao; Yoshiki Eto; Hayato Furumoto; Bernard M. Hang’Ombe; Yasuko Orba; Hirofumi Sawa; Edgar Simulundu; Shuetsu Fukushi; Shigeru Morikawa; Masayuki Saijo; Jiro Arikawa; Swithine Kabilika; Mwaka Monze; Victor Mukonka; Aaron Mweene; Ayato Takada; Kumiko Yoshimatsu. 2021. "Serologic and molecular evidence for circulation of Crimean-Congo hemorrhagic fever virus in ticks and cattle in Zambia." PLOS Neglected Tropical Diseases 15, no. 6: e0009452.

Preprint content
Published: 12 April 2021
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The COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2, has a global impact on public health. Since glycosylation of the viral envelope glycoproteins is known to be deeply associated with their immunogenicity, intensive studies on the glycans of its major glycoprotein, S protein, have been conducted. Nevertheless, the detailed site-specific glycan compositions of virion-associated S protein have not yet been clarified. Here, we conducted intensive glycoproteomic analyses of SARS-CoV-2 S protein using a combinatorial approach with two different technologies: mass spectrometry (MS) and lectin microarray. Using our unique MS1-based glycoproteomic technique, Glyco-RIDGE, in addition to MS2-based Byonic search, we identified 1,759 site-specific glycan compositions. The most frequent was HexNAc:Hex:Fuc:NeuAc:NeuGc = 6:6:1:0:0, suggesting a tri-antennary N-glycan terminating with LacNAc and having bisecting GlcNAc and a core fucose, which was found in 20 of 22 glycosylated sites. The subsequent lectin microarray analysis emphasized intensive outer arm fucosylation of glycans, which efficiently complemented the glycoproteomic features. The present results illustrate the high-resolution glycoproteomic features of SARS-CoV-2 S protein and significantly contribute to vaccine design, as well as the understanding of viral protein synthesis.

ACS Style

Takahiro Hiono; Azusa Tomioka; Hiroyuki Kaji; Michihito Sasaki; Yasuko Orba; Hirofumi Sawa; Atsushi Kuno. Combinatorial approach with mass spectrometry and lectin microarray dissected glycoproteomic features of virion-derived spike protein of SARS-CoV-2. 2021, 1 .

AMA Style

Takahiro Hiono, Azusa Tomioka, Hiroyuki Kaji, Michihito Sasaki, Yasuko Orba, Hirofumi Sawa, Atsushi Kuno. Combinatorial approach with mass spectrometry and lectin microarray dissected glycoproteomic features of virion-derived spike protein of SARS-CoV-2. . 2021; ():1.

Chicago/Turabian Style

Takahiro Hiono; Azusa Tomioka; Hiroyuki Kaji; Michihito Sasaki; Yasuko Orba; Hirofumi Sawa; Atsushi Kuno. 2021. "Combinatorial approach with mass spectrometry and lectin microarray dissected glycoproteomic features of virion-derived spike protein of SARS-CoV-2." , no. : 1.

Communication
Published: 28 February 2021 in Viruses
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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) utilizes host proteases, including a plasma membrane-associated transmembrane protease, serine 2 (TMPRSS2) to cleave and activate the virus spike protein to facilitate cellular entry. Although TMPRSS2 is a well-characterized type II transmembrane serine protease (TTSP), the role of other TTSPs on the replication of SARS-CoV-2 remains to be elucidated. Here, we have screened 12 TTSPs using human angiotensin-converting enzyme 2-expressing HEK293T (293T-ACE2) cells and Vero E6 cells and demonstrated that exogenous expression of TMPRSS11D and TMPRSS13 enhanced cellular uptake and subsequent replication of SARS-CoV-2. In addition, SARS-CoV-1 and SARS-CoV-2 share the same TTSPs in the viral entry process. Our study demonstrates the impact of host TTSPs on infection of SARS-CoV-2, which may have implications for cell and tissue tropism, for pathogenicity, and potentially for vaccine development.

ACS Style

Mai Kishimoto; Kentaro Uemura; Takao Sanaki; Akihiko Sato; William Hall; Hiroaki Kariwa; Yasuko Orba; Hirofumi Sawa; Michihito Sasaki. TMPRSS11D and TMPRSS13 Activate the SARS-CoV-2 Spike Protein. Viruses 2021, 13, 384 .

AMA Style

Mai Kishimoto, Kentaro Uemura, Takao Sanaki, Akihiko Sato, William Hall, Hiroaki Kariwa, Yasuko Orba, Hirofumi Sawa, Michihito Sasaki. TMPRSS11D and TMPRSS13 Activate the SARS-CoV-2 Spike Protein. Viruses. 2021; 13 (3):384.

Chicago/Turabian Style

Mai Kishimoto; Kentaro Uemura; Takao Sanaki; Akihiko Sato; William Hall; Hiroaki Kariwa; Yasuko Orba; Hirofumi Sawa; Michihito Sasaki. 2021. "TMPRSS11D and TMPRSS13 Activate the SARS-CoV-2 Spike Protein." Viruses 13, no. 3: 384.

Journal article
Published: 03 February 2021 in Journal of General Virology
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Encephalomyocarditis virus (EMCV) infects a wide range of hosts and can cause encephalitis, myocarditis, reproductive disorders and diabetes mellitus in selected mammalian species. As for humans, EMCV infection seems to occur by the contact with animals and can cause febrile illnesses in some infected patients. Here we isolated EMCV strain ZM12/14 from a natal multimammate mouse (Mastomys natalensis: M. natalensis) in Zambia. Pairwise sequence similarity of the ZM12/14 P1 region consisting of antigenic capsid proteins showed the highest similarity of nucleotide (80.7 %) and amino acid (96.2%) sequence with EMCV serotype 1 (EMCV-1). Phylogenetic analysis revealed that ZM12/14 clustered into EMCV-1 at the P1 and P3 regions but segregated from known EMCV strains at the P2 region, suggesting a unique evolutionary history. Reverse transcription PCR (RT-PCR) screening and neutralizing antibody assays for EMCV were performed using collected tissues and serum from various rodents (n=179) captured in different areas in Zambia. We detected the EMCV genome in 19 M. natalensis (19/179=10.6 %) and neutralizing antibody for EMCV in 33 M. natalensis (33/179=18.4 %). However, we did not detect either the genome or neutralizing antibody in other rodent species. High neutralizing antibody litres (≧320) were observed in both RT-PCR-negative and -positive animals. Inoculation of ZM12/14 caused asymptomatic persistent infection in BALB/c mice with high antibody titres and high viral loads in some organs, consistent with the above epidemiological results. This study is the first report of the isolation of EMCV in Zambia, suggesting that M. natalensis may play a role as a natural reservoir of infection.

ACS Style

Mai Kishimoto; Bernard M. Hang’Ombe; William W. Hall; Yasuko Orba; Hirofumi Sawa; Michihito Sasaki. Mastomys natalensis is a possible natural rodent reservoir for encephalomyocarditis virus. Journal of General Virology 2021, 001564 .

AMA Style

Mai Kishimoto, Bernard M. Hang’Ombe, William W. Hall, Yasuko Orba, Hirofumi Sawa, Michihito Sasaki. Mastomys natalensis is a possible natural rodent reservoir for encephalomyocarditis virus. Journal of General Virology. 2021; ():001564.

Chicago/Turabian Style

Mai Kishimoto; Bernard M. Hang’Ombe; William W. Hall; Yasuko Orba; Hirofumi Sawa; Michihito Sasaki. 2021. "Mastomys natalensis is a possible natural rodent reservoir for encephalomyocarditis virus." Journal of General Virology , no. : 001564.

Research article
Published: 21 January 2021 in PLOS Pathogens
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The spike (S) protein of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) binds to a host cell receptor which facilitates viral entry. A polybasic motif detected at the cleavage site of the S protein has been shown to broaden the cell tropism and transmissibility of the virus. Here we examine the properties of SARS-CoV-2 variants with mutations at the S protein cleavage site that undergo inefficient proteolytic cleavage. Virus variants with S gene mutations generated smaller plaques and exhibited a more limited range of cell tropism compared to the wild-type strain. These alterations were shown to result from their inability to utilize the entry pathway involving direct fusion mediated by the host type II transmembrane serine protease, TMPRSS2. Notably, viruses with S gene mutations emerged rapidly and became the dominant SARS-CoV-2 variants in TMPRSS2-deficient cells including Vero cells. Our study demonstrated that the S protein polybasic cleavage motif is a critical factor underlying SARS-CoV-2 entry and cell tropism. As such, researchers should be alert to the possibility of de novo S gene mutations emerging in tissue-culture propagated virus strains.

ACS Style

Michihito Sasaki; Kentaro Uemura; Akihiko Sato; Shinsuke Toba; Takao Sanaki; Katsumi Maenaka; William W. Hall; Yasuko Orba; Hirofumi Sawa. SARS-CoV-2 variants with mutations at the S1/S2 cleavage site are generated in vitro during propagation in TMPRSS2-deficient cells. PLOS Pathogens 2021, 17, e1009233 .

AMA Style

Michihito Sasaki, Kentaro Uemura, Akihiko Sato, Shinsuke Toba, Takao Sanaki, Katsumi Maenaka, William W. Hall, Yasuko Orba, Hirofumi Sawa. SARS-CoV-2 variants with mutations at the S1/S2 cleavage site are generated in vitro during propagation in TMPRSS2-deficient cells. PLOS Pathogens. 2021; 17 (1):e1009233.

Chicago/Turabian Style

Michihito Sasaki; Kentaro Uemura; Akihiko Sato; Shinsuke Toba; Takao Sanaki; Katsumi Maenaka; William W. Hall; Yasuko Orba; Hirofumi Sawa. 2021. "SARS-CoV-2 variants with mutations at the S1/S2 cleavage site are generated in vitro during propagation in TMPRSS2-deficient cells." PLOS Pathogens 17, no. 1: e1009233.

Journal article
Published: 08 January 2021 in Journal of General Virology
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The genus Flavivirus includes a range of mosquito-specific viruses in addition to well-known medically important arboviruses. Isolation and comprehensive genomic analyses of viruses in mosquitoes collected in Bolivia resulted in the identification of three novel flavivirus species. Psorophora flavivirus (PSFV) was isolated from Psorophora albigenu. The coding sequence of the PSFV polyprotein shares 60 % identity with that of the Aedes-associated lineage II insect-specific flavivirus (ISF), Marisma virus. Isolated PSFV replicates in both Aedes albopictus- and Aedes aegypti-derived cells, but not in mammalian Vero or BHK-21 cell lines. Two other flaviviruses, Ochlerotatus scapularis flavivirus (OSFV) and Mansonia flavivirus (MAFV), which were identified from Ochlerotatus scapularis and Mansonia titillans, respectively, group with the classical lineage I ISFs. The protein coding sequences of these viruses share only 60 and 40 % identity with the most closely related of known lineage I ISFs, including Xishuangbanna aedes flavivirus and Sabethes flavivirus, respectively. Phylogenetic analysis suggests that MAFV is clearly distinct from the groups of the current known Culicinae-associated lineage I ISFs. Interestingly, the predicted amino acid sequence of the MAFV capsid protein is approximately two times longer than that of any of the other known flaviviruses. Our results indicate that flaviviruses with distinct features can be found at the edge of the Bolivian Amazon basin at sites that are also home to dense populations of human-biting mosquitoes.

ACS Style

Yasuko Orba; Keita Matsuno; Ryo Nakao; Kirill Kryukov; Yumi Saito; Fumihiko Kawamori; Ariel Loza Vega; Tokiko Watanabe; Tadashi Maemura; Michihito Sasaki; William W. Hall; Roy A. Hall; Juan Antonio Pereira; So Nakagawa; Hirofumi Sawa. Diverse mosquito-specific flaviviruses in the Bolivian Amazon basin. Journal of General Virology 2021, 001518 .

AMA Style

Yasuko Orba, Keita Matsuno, Ryo Nakao, Kirill Kryukov, Yumi Saito, Fumihiko Kawamori, Ariel Loza Vega, Tokiko Watanabe, Tadashi Maemura, Michihito Sasaki, William W. Hall, Roy A. Hall, Juan Antonio Pereira, So Nakagawa, Hirofumi Sawa. Diverse mosquito-specific flaviviruses in the Bolivian Amazon basin. Journal of General Virology. 2021; ():001518.

Chicago/Turabian Style

Yasuko Orba; Keita Matsuno; Ryo Nakao; Kirill Kryukov; Yumi Saito; Fumihiko Kawamori; Ariel Loza Vega; Tokiko Watanabe; Tadashi Maemura; Michihito Sasaki; William W. Hall; Roy A. Hall; Juan Antonio Pereira; So Nakagawa; Hirofumi Sawa. 2021. "Diverse mosquito-specific flaviviruses in the Bolivian Amazon basin." Journal of General Virology , no. : 001518.

Journal article
Published: 12 October 2020 in International Journal of Molecular Sciences
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Efforts to determine the mosquito genes that affect dengue virus replication have identified a number of candidates that positively or negatively modify amplification in the invertebrate host. We used deep sequencing to compare the differential transcript abundances in Aedes aegypti 14 days post dengue infection to those of uninfected Ae. aegypti. The gene lethal(2)-essential-for-life [l(2)efl], which encodes a member of the heat shock 20 protein (HSP20) family, was upregulated following dengue virus type 2 (DENV-2) infection in vivo. The transcripts of this gene did not exhibit differential accumulation in mosquitoes exposed to insecticides or pollutants. The induction and overexpression of l(2)efl gene products using poly(I:C) resulted in decreased DENV-2 replication in the cell line. In contrast, the RNAi-mediated suppression of l(2)efl gene products resulted in enhanced DENV-2 replication, but this enhancement occurred only if multiple l(2)efl genes were suppressed. l(2)efl homologs induce the phosphorylation of eukaryotic initiation factor 2α (eIF2α) in the fruit fly Drosophila melanogaster, and we confirmed this finding in the cell line. However, the mechanism by which l(2)efl phosphorylates eIF2α remains unclear. We conclude that l(2)efl encodes a potential anti-dengue protein in the vector mosquito.

ACS Style

Lucky R. Runtuwene; Shuichi Kawashima; Victor D. Pijoh; Josef S. B. Tuda; Kyoko Hayashida; Junya Yamagishi; Chihiro Sugimoto; Shoko Nishiyama; Michihito Sasaki; Yasuko Orba; Hirofumi Sawa; Tomohiko Takasaki; Anthony A. James; Takashi Kobayashi; Yuki Eshita. The Lethal(2)-Essential-for-Life [L(2)EFL] Gene Family Modulates Dengue Virus Infection in Aedes aegypti. International Journal of Molecular Sciences 2020, 21, 7520 .

AMA Style

Lucky R. Runtuwene, Shuichi Kawashima, Victor D. Pijoh, Josef S. B. Tuda, Kyoko Hayashida, Junya Yamagishi, Chihiro Sugimoto, Shoko Nishiyama, Michihito Sasaki, Yasuko Orba, Hirofumi Sawa, Tomohiko Takasaki, Anthony A. James, Takashi Kobayashi, Yuki Eshita. The Lethal(2)-Essential-for-Life [L(2)EFL] Gene Family Modulates Dengue Virus Infection in Aedes aegypti. International Journal of Molecular Sciences. 2020; 21 (20):7520.

Chicago/Turabian Style

Lucky R. Runtuwene; Shuichi Kawashima; Victor D. Pijoh; Josef S. B. Tuda; Kyoko Hayashida; Junya Yamagishi; Chihiro Sugimoto; Shoko Nishiyama; Michihito Sasaki; Yasuko Orba; Hirofumi Sawa; Tomohiko Takasaki; Anthony A. James; Takashi Kobayashi; Yuki Eshita. 2020. "The Lethal(2)-Essential-for-Life [L(2)EFL] Gene Family Modulates Dengue Virus Infection in Aedes aegypti." International Journal of Molecular Sciences 21, no. 20: 7520.

Journal article
Published: 06 October 2020 in International Journal of Infectious Diseases
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Since its first discovery in December 2019 in Wuhan, China, COVID-19, caused by the novel coronavirus SARS-CoV-2, has spread rapidly worldwide. Whilst African countries were relatively spared initially, the initial low incidence of COVID-19 cases was not sustained for long due to continuing travel links between China, Europe and Africa.. In preparation, Zambia had applied a multisectoral national epidemic disease surveillance and response system resulting in the identification of the first case within 48 hours of the individual entering the country by air travel from a trip to France. Contact tracing showed that SARS-CoV-2 infection was contained within the patient's household, with no further spread to attending health care workers or community members. Phylogenomic analysis of the patient's SARS-CoV-2 strain showed it belonged to lineage B.1.1., sharing the last common ancestor with SARS-CoV-2 strains recovered from South Africa. At the African continental level, our analysis showed that lineage B.1 and B.1.1 lineages appear to be predominant in Africa. Whole genome sequence analysis should be part of all surveillance and case detection activities in order to monitor the origin and evolution of SARS-CoV-2 lineages across Africa.

ACS Style

Edgar Simulundu; Francis Mupeta; Pascalina Chanda-Kapata; Ngonda Saasa; Katendi Changula; Walter Muleya; Simbarashe Chitanga; Miniva Mwanza; Paul Simusika; Herman Chambaro; Benjamin Mubemba; Masahiro Kajihara; Duncan Chanda; Lloyd Mulenga; Sombo Fwoloshi; Aaron Lunda Shibemba; Fred Kapaya; Paul Zulu; Kunda Musonda; Mwaka Monze; Nyambe Sinyange; Mazyanga L. Mazaba; Muzala Kapin’A; Peter J. Chipimo; Raymond Hamoonga; Davie Simwaba; William Ngosa; Albertina N. Morales; Nkomba Kayeyi; John Tembo; Mathew Bates; Yasuko Orba; Hirofumi Sawa; Ayato Takada; King S. Nalubamba; Kennedy Malama; Victor Mukonka; Alimuddin Zumla; Nathan Kapata. First COVID-19 case in Zambia — Comparative phylogenomic analyses of SARS-CoV-2 detected in African countries. International Journal of Infectious Diseases 2020, 102, 455 -459.

AMA Style

Edgar Simulundu, Francis Mupeta, Pascalina Chanda-Kapata, Ngonda Saasa, Katendi Changula, Walter Muleya, Simbarashe Chitanga, Miniva Mwanza, Paul Simusika, Herman Chambaro, Benjamin Mubemba, Masahiro Kajihara, Duncan Chanda, Lloyd Mulenga, Sombo Fwoloshi, Aaron Lunda Shibemba, Fred Kapaya, Paul Zulu, Kunda Musonda, Mwaka Monze, Nyambe Sinyange, Mazyanga L. Mazaba, Muzala Kapin’A, Peter J. Chipimo, Raymond Hamoonga, Davie Simwaba, William Ngosa, Albertina N. Morales, Nkomba Kayeyi, John Tembo, Mathew Bates, Yasuko Orba, Hirofumi Sawa, Ayato Takada, King S. Nalubamba, Kennedy Malama, Victor Mukonka, Alimuddin Zumla, Nathan Kapata. First COVID-19 case in Zambia — Comparative phylogenomic analyses of SARS-CoV-2 detected in African countries. International Journal of Infectious Diseases. 2020; 102 ():455-459.

Chicago/Turabian Style

Edgar Simulundu; Francis Mupeta; Pascalina Chanda-Kapata; Ngonda Saasa; Katendi Changula; Walter Muleya; Simbarashe Chitanga; Miniva Mwanza; Paul Simusika; Herman Chambaro; Benjamin Mubemba; Masahiro Kajihara; Duncan Chanda; Lloyd Mulenga; Sombo Fwoloshi; Aaron Lunda Shibemba; Fred Kapaya; Paul Zulu; Kunda Musonda; Mwaka Monze; Nyambe Sinyange; Mazyanga L. Mazaba; Muzala Kapin’A; Peter J. Chipimo; Raymond Hamoonga; Davie Simwaba; William Ngosa; Albertina N. Morales; Nkomba Kayeyi; John Tembo; Mathew Bates; Yasuko Orba; Hirofumi Sawa; Ayato Takada; King S. Nalubamba; Kennedy Malama; Victor Mukonka; Alimuddin Zumla; Nathan Kapata. 2020. "First COVID-19 case in Zambia — Comparative phylogenomic analyses of SARS-CoV-2 detected in African countries." International Journal of Infectious Diseases 102, no. : 455-459.

Journal article
Published: 11 September 2020 in Viruses
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To monitor the arthropod-borne virus transmission in mosquitoes, we have attempted both to detect and isolate viruses from 3304 wild-caught female mosquitoes in the Livingstone (Southern Province) and Mongu (Western Province) regions in Zambia in 2017. A pan-flavivirus RT-PCR assay was performed to identify flavivirus genomes in total RNA extracted from mosquito lysates, followed by virus isolation and full genome sequence analysis using next-generation sequencing and rapid amplification of cDNA ends. We isolated a newly identified Barkedji virus (BJV Zambia) (10,899 nt) and a novel flavivirus, tentatively termed Barkedji-like virus (BJLV) (10,885 nt) from Culex spp. mosquitoes which shared 96% and 75% nucleotide identity with BJV which has been isolated in Israel, respectively. These viruses could replicate in C6/36 cells but not in mammalian and avian cell lines. In parallel, a comparative genomics screening was conducted to study evolutionary traits of the 5′- and 3′-untranslated regions (UTRs) of isolated viruses. Bioinformatic analyses of the secondary structures in the UTRs of both viruses revealed that the 5′-UTRs exhibit canonical stem-loop structures, while the 3′-UTRs contain structural homologs to exoribonuclease-resistant RNAs (xrRNAs), SL-III, dumbbell, and terminal stem-loop (3′SL) structures. The function of predicted xrRNA structures to stop RNA degradation by Xrn1 exoribonuclease was further proved by the in vitro Xrn1 resistance assay.

ACS Style

Christida E. Wastika; Hayato Harima; Michihito Sasaki; Bernard M. Hang’Ombe; Yuki Eshita; Yongjin Qiu; William W. Hall; Michael T. Wolfinger; Hirofumi Sawa; Yasuko Orba. Discoveries of Exoribonuclease-Resistant Structures of Insect-Specific Flaviviruses Isolated in Zambia. Viruses 2020, 12, 1017 .

AMA Style

Christida E. Wastika, Hayato Harima, Michihito Sasaki, Bernard M. Hang’Ombe, Yuki Eshita, Yongjin Qiu, William W. Hall, Michael T. Wolfinger, Hirofumi Sawa, Yasuko Orba. Discoveries of Exoribonuclease-Resistant Structures of Insect-Specific Flaviviruses Isolated in Zambia. Viruses. 2020; 12 (9):1017.

Chicago/Turabian Style

Christida E. Wastika; Hayato Harima; Michihito Sasaki; Bernard M. Hang’Ombe; Yuki Eshita; Yongjin Qiu; William W. Hall; Michael T. Wolfinger; Hirofumi Sawa; Yasuko Orba. 2020. "Discoveries of Exoribonuclease-Resistant Structures of Insect-Specific Flaviviruses Isolated in Zambia." Viruses 12, no. 9: 1017.

Journal article
Published: 31 August 2020 in Viruses
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Bluetongue (BT) is an arthropod-borne viral disease of ruminants with serious trade and socio-economic implications. Although the disease has been reported in a number of countries in sub-Saharan Africa, there is currently no information on circulating serotypes and disease distribution in Zambia. Following surveillance for BT in domestic and wild ruminants in Zambia, BT virus (BTV) nucleic acid and antibodies were detected in eight of the 10 provinces of the country. About 40% (87/215) of pooled blood samples from cattle and goats were positive for BTV nucleic acid, while one hartebeest pool (1/43) was positive among wildlife samples. Sequence analysis of segment 2 revealed presence of serotypes 3, 5, 7, 12 and 15, with five nucleotypes (B, E, F, G and J) being identified. Segment 10 phylogeny showed Zambian BTV sequences clustering with Western topotype strains from South Africa, intimating likely transboundary spread of BTV in Southern Africa. Interestingly, two Zambian viruses and one isolate from Israel formed a novel clade, which we designated as Western topotype 4. The high seroprevalence (96.2%) in cattle from Lusaka and Central provinces and co-circulation of multiple serotypes showed that BT is widespread, underscoring the need for prevention and control strategies.

ACS Style

Herman M. Chambaro; Michihito Sasaki; Edgar Simulundu; Isaac Silwamba; Yona Sinkala; Gabriel Gonzalez; David Squarre; Paul Fandamu; Caesar H. Lubaba; Musso Munyeme; Alikhadio Maseko; Choopa Chimvwele; Liywalii Mataa; Lynnfield E. Mooya; Andrew N. Mukubesa; Hayato Harima; Kenny L. Samui; Hetron M. Munang’Andu; Martin Simuunza; King S. Nalubamba; Yongjin Qiu; Michael J. Carr; William W. Hall; Yuki Eshita; Hirofumi Sawa; Yasuko Orba. Co-Circulation of Multiple Serotypes of Bluetongue Virus in Zambia. Viruses 2020, 12, 963 .

AMA Style

Herman M. Chambaro, Michihito Sasaki, Edgar Simulundu, Isaac Silwamba, Yona Sinkala, Gabriel Gonzalez, David Squarre, Paul Fandamu, Caesar H. Lubaba, Musso Munyeme, Alikhadio Maseko, Choopa Chimvwele, Liywalii Mataa, Lynnfield E. Mooya, Andrew N. Mukubesa, Hayato Harima, Kenny L. Samui, Hetron M. Munang’Andu, Martin Simuunza, King S. Nalubamba, Yongjin Qiu, Michael J. Carr, William W. Hall, Yuki Eshita, Hirofumi Sawa, Yasuko Orba. Co-Circulation of Multiple Serotypes of Bluetongue Virus in Zambia. Viruses. 2020; 12 (9):963.

Chicago/Turabian Style

Herman M. Chambaro; Michihito Sasaki; Edgar Simulundu; Isaac Silwamba; Yona Sinkala; Gabriel Gonzalez; David Squarre; Paul Fandamu; Caesar H. Lubaba; Musso Munyeme; Alikhadio Maseko; Choopa Chimvwele; Liywalii Mataa; Lynnfield E. Mooya; Andrew N. Mukubesa; Hayato Harima; Kenny L. Samui; Hetron M. Munang’Andu; Martin Simuunza; King S. Nalubamba; Yongjin Qiu; Michael J. Carr; William W. Hall; Yuki Eshita; Hirofumi Sawa; Yasuko Orba. 2020. "Co-Circulation of Multiple Serotypes of Bluetongue Virus in Zambia." Viruses 12, no. 9: 963.

Original article
Published: 20 May 2020 in Transboundary and Emerging Diseases
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African swine fever (ASF) causes persistent outbreaks in endemic and non‐endemic regions in Zambia. However, the epidemiology of the disease is poorly understood, particularly during the inter‐epidemic periods. We conducted surveillance for ASF in asymptomatic domestic pigs and soft ticks in selected Zambian provinces. Whilst serum samples (n=1,134) were collected from crossbred pigs from all study sites between 2014 and 2017, whole blood (n=300) was collected from both crossbred and indigenous pigs in Eastern Province (EP) in 2017. Soft ticks were collected from Mosi‐oa‐Tunya National Park in Southern Province (SP) in 2019. Sera were screened for antibodies against ASF by ELISA while genome detection in whole blood and soft ticks was conducted by PCR. Ticks were identified morphologically and by phylogenetic analysis of the 16S rRNA gene. Seroprevalence was highest in EP (50.9%, 95% CI [47.0 – 54.9]) compared to significantly lower rates in SP (2.9%, 95% CI [1.6 – 5.1]). No antibodies to ASFV were detected in Lusaka Province. In EP, the prevalence of ASFV genome was 11.7% (35/300), significantly higher (OR = 6.2, 95% CI [2.4 – 16.6]) in indigenous pigs compared to crossbred pigs. The pooled prevalence of ASFV genome in ticks was 11.0%, 95% CI [8.5–13.9]. Free‐range husbandry system was the only factor that was significantly associated with seropositive (p < 0.0001, OR = 39.3) and PCR positive results (p < 0.001, OR = 5.7). Phylogenetically, based on the p72 gene, ASFV from Ornithodoros moubata ticks detected in this study belonged to genotype I, but they separated into two distinct clusters. Besides confirming ASF endemicity in EP and the presence of ASFV‐infected ticks in SP, these results provide evidence for exposure of domestic pigs to ASFV in non‐endemic regions during the inter‐epidemic period.

ACS Style

Herman M. Chambaro; Michihito Sasaki; Yona Sinkala; Gabriel Gonzalez; David Squarre; Paul Fandamu; Caesar Lubaba; Liywalii Mataa; Misheck Shawa; Kabemba E. Mwape; Sarah Gabriël; Mwelwa Chembensofu; Michael Carr; William W. Hall; Yongjin Qiu; Masahiro Kajihara; Ayato Takada; Yasuko Orba; Edgar Simulundu; Hirofumi Sawa. Evidence for exposure of asymptomatic domestic pigs to African swine fever virus during an inter‐epidemic period in Zambia. Transboundary and Emerging Diseases 2020, 67, 2741 -2752.

AMA Style

Herman M. Chambaro, Michihito Sasaki, Yona Sinkala, Gabriel Gonzalez, David Squarre, Paul Fandamu, Caesar Lubaba, Liywalii Mataa, Misheck Shawa, Kabemba E. Mwape, Sarah Gabriël, Mwelwa Chembensofu, Michael Carr, William W. Hall, Yongjin Qiu, Masahiro Kajihara, Ayato Takada, Yasuko Orba, Edgar Simulundu, Hirofumi Sawa. Evidence for exposure of asymptomatic domestic pigs to African swine fever virus during an inter‐epidemic period in Zambia. Transboundary and Emerging Diseases. 2020; 67 (6):2741-2752.

Chicago/Turabian Style

Herman M. Chambaro; Michihito Sasaki; Yona Sinkala; Gabriel Gonzalez; David Squarre; Paul Fandamu; Caesar Lubaba; Liywalii Mataa; Misheck Shawa; Kabemba E. Mwape; Sarah Gabriël; Mwelwa Chembensofu; Michael Carr; William W. Hall; Yongjin Qiu; Masahiro Kajihara; Ayato Takada; Yasuko Orba; Edgar Simulundu; Hirofumi Sawa. 2020. "Evidence for exposure of asymptomatic domestic pigs to African swine fever virus during an inter‐epidemic period in Zambia." Transboundary and Emerging Diseases 67, no. 6: 2741-2752.

Journal article
Published: 30 November 2018 in Japanese Journal of Infectious Diseases
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Dengue virus (DENV) has a considerable impact on global health and causes morbidity and mortality each year. Through the passages of a DENV2 in BHK-21 cells, we have isolated a mutant clone of DENV2 which reveals cytopathic effects (CPE) rapidly compared to the parent strain in BHK-21 cells. To investigate the relationship between amino acid mutations and proliferation activity of the isolated DENV2 clone, we performed full genome sequencing and identified three amino acid mutations in its coding region, the Envelope (Env) T120K, NS4A M85T and NS4B G124A, compared to that of the parent strain. Genetically-modified recombinant DENV2 (rDENV2) carrying the NS4A M85T and NS4B G124A mutations produced higher titers of progeny virus in BHK-21, Vero and Huh-7 cells compared to wild-type (WT) rDENV2. Surprisingly, rDENV2 with mutations at NS4A M85T and NS4B G124A did not produce any plaques in C6/36 mosquito cell lines. Furthermore, rDENV2 possessing only the NS4B G124A mutation did not produce any plaques in C6/36 cells; however, it had higher viral titers in Vero and Huh-7 cells compared to WT rDENV2. Our results clearly showed that the DENV2 NS4B G124A mutation has opposing effects on viral proliferation in certain mammalian cells and mosquito cells.

ACS Style

Jumpei Fujiki; Haruaki Nobori; Akihiko Sato; Michihito Sasaki; Michael Carr; William Walmsley Hall; Yasuko Orba; Hirofumi Sawa. Single Amino Acid Mutation in Dengue Virus NS4B Protein Has Opposing Effects on Viral Proliferation in Mammalian and Mosquito Cells. Japanese Journal of Infectious Diseases 2018, 71, 448 -454.

AMA Style

Jumpei Fujiki, Haruaki Nobori, Akihiko Sato, Michihito Sasaki, Michael Carr, William Walmsley Hall, Yasuko Orba, Hirofumi Sawa. Single Amino Acid Mutation in Dengue Virus NS4B Protein Has Opposing Effects on Viral Proliferation in Mammalian and Mosquito Cells. Japanese Journal of Infectious Diseases. 2018; 71 (6):448-454.

Chicago/Turabian Style

Jumpei Fujiki; Haruaki Nobori; Akihiko Sato; Michihito Sasaki; Michael Carr; William Walmsley Hall; Yasuko Orba; Hirofumi Sawa. 2018. "Single Amino Acid Mutation in Dengue Virus NS4B Protein Has Opposing Effects on Viral Proliferation in Mammalian and Mosquito Cells." Japanese Journal of Infectious Diseases 71, no. 6: 448-454.

Case report
Published: 12 November 2018 in Pathology International
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A 24 year‐old female presented with a mass lesion in the right temporal lobe. This case was difficult to diagnose using histological and immunological methods and therefore molecular analyses were applied to provide a definitive diagnosis. The tumor was well‐demarcated, partially cystic, and irregularly‐enhanced on gadolinium‐enhanced T1‐weighted magnetic resonance images. Pathologically, a large part of the tumor consisted of cells with fine cytoplasmic processes on a myxoid and mucinous background. Cells formed a microcystic structure around the mucinous tissue. Numerous eosinophilic granular bodies, but not Rosenthal fibers, were present. The solid and compact regions of the tumor were composed of fasciculation of dense fibrous glial tissues and occasional multinucleated giant cells. Tumor cells and their fragmented cytoplasmic processes were positively stained with GFAP, while eosinophilic granular bodies were both positive and negative. Xanthomatous changes were not detected and the reticulin fibers were restricted to vascular tissues. The MIB1 index was scored as approximately 10%. In molecular analyses of BRAF, the KIAA1549‐BRAF (K16‐B9) fusion gene was detected in all tumor regions, whereas BRAF V600E mutation was not detected by either conventional Sanger sequencing or the Eprobe‐PCR method. Based on the results of the molecular analyses, this case was diagnosed as pilocytic astrocytoma.

ACS Style

Yusuke Ishida; Masumi Tsuda; Yutaka Sawamura; Kyoko Fujii; Hiroshi Murai; Naruyoshi Horiuchi; Yasuko Orba; Hirofumi Sawa; William W Hall; Kazuo Nagashima; Shinya Tanaka. “Integrated diagnosis” of pilocytic astrocytoma: Molecular diagnostic procedure for an unusual case. Pathology International 2018, 68, 694 -699.

AMA Style

Yusuke Ishida, Masumi Tsuda, Yutaka Sawamura, Kyoko Fujii, Hiroshi Murai, Naruyoshi Horiuchi, Yasuko Orba, Hirofumi Sawa, William W Hall, Kazuo Nagashima, Shinya Tanaka. “Integrated diagnosis” of pilocytic astrocytoma: Molecular diagnostic procedure for an unusual case. Pathology International. 2018; 68 (12):694-699.

Chicago/Turabian Style

Yusuke Ishida; Masumi Tsuda; Yutaka Sawamura; Kyoko Fujii; Hiroshi Murai; Naruyoshi Horiuchi; Yasuko Orba; Hirofumi Sawa; William W Hall; Kazuo Nagashima; Shinya Tanaka. 2018. "“Integrated diagnosis” of pilocytic astrocytoma: Molecular diagnostic procedure for an unusual case." Pathology International 68, no. 12: 694-699.

Journal article
Published: 01 July 2018 in Antiviral Research
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Dengue virus (DENV) is the causative agent of dengue fever and dengue hemorrhagic fever/dengue shock syndrome. At present, no antiviral drugs are available for treatment DENV infections. In this study, a screening system based on a DENV-infected cell-based assay identified a novel anti-DENV agent with a benzimidazole skeleton, named Compound-B, which demonstrated antiviral activity specific to four DENV serotypes (EC50: 1.32-4.12 μM). Analysis of a single amino acid substitution of Compound-B-resistant DENV2 revealed that mutation C87S in the non-structural protein 4A (NS4A) contributes to resistance to Compound-B.

ACS Style

Haruaki Nobori; Shinsuke Toba; Ryu Yoshida; William W. Hall; Yasuko Orba; Hirofumi Sawa; Akihiko Sato. Identification of Compound-B, a novel anti-dengue virus agent targeting the non-structural protein 4A. Antiviral Research 2018, 155, 60 -66.

AMA Style

Haruaki Nobori, Shinsuke Toba, Ryu Yoshida, William W. Hall, Yasuko Orba, Hirofumi Sawa, Akihiko Sato. Identification of Compound-B, a novel anti-dengue virus agent targeting the non-structural protein 4A. Antiviral Research. 2018; 155 ():60-66.

Chicago/Turabian Style

Haruaki Nobori; Shinsuke Toba; Ryu Yoshida; William W. Hall; Yasuko Orba; Hirofumi Sawa; Akihiko Sato. 2018. "Identification of Compound-B, a novel anti-dengue virus agent targeting the non-structural protein 4A." Antiviral Research 155, no. : 60-66.

Journals
Published: 04 May 2018 in RSC Advances
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Conjugation with gold nanorods enhanced the adjuvanticity of RNA adjuvant for intranasal inactivated influenza vaccines, providing efficient protection against infection in mice.

ACS Style

Taiyu Tazaki; Koshiro Tabata; Akira Ainai; Yuki Ohara; Shintaro Kobayashi; Takafumi Ninomiya; Yasuko Orba; Hideyuki Mitomo; Tetsuo Nakano; Hideki Hasegawa; Kuniharu Ijiro; Hirofumi Sawa; Tadaki Suzuki; Kenichi Niikura. Shape-dependent adjuvanticity of nanoparticle-conjugated RNA adjuvants for intranasal inactivated influenza vaccines. RSC Advances 2018, 8, 16527 -16536.

AMA Style

Taiyu Tazaki, Koshiro Tabata, Akira Ainai, Yuki Ohara, Shintaro Kobayashi, Takafumi Ninomiya, Yasuko Orba, Hideyuki Mitomo, Tetsuo Nakano, Hideki Hasegawa, Kuniharu Ijiro, Hirofumi Sawa, Tadaki Suzuki, Kenichi Niikura. Shape-dependent adjuvanticity of nanoparticle-conjugated RNA adjuvants for intranasal inactivated influenza vaccines. RSC Advances. 2018; 8 (30):16527-16536.

Chicago/Turabian Style

Taiyu Tazaki; Koshiro Tabata; Akira Ainai; Yuki Ohara; Shintaro Kobayashi; Takafumi Ninomiya; Yasuko Orba; Hideyuki Mitomo; Tetsuo Nakano; Hideki Hasegawa; Kuniharu Ijiro; Hirofumi Sawa; Tadaki Suzuki; Kenichi Niikura. 2018. "Shape-dependent adjuvanticity of nanoparticle-conjugated RNA adjuvants for intranasal inactivated influenza vaccines." RSC Advances 8, no. 30: 16527-16536.

Short communication
Published: 06 April 2018 in Virus Research
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Mosquito-borne alphaviruses are disseminated globally and cause febrile illness in humans and animals. Since the prevalence and diversity of alphaviruses has not been previously investigated in Zambia, reverse transcription PCR was employed as a broad-spectrum approach for the detection of alphaviruses in mosquitoes. From 552 mosquito pools, a novel alphavirus, tentatively named Mwinilunga alphavirus (MWAV), was discovered from a single Culex quinquefasciatus mosquito pool. The full genome of MWAV was subsequently determined, and pairwise comparisons demonstrated that MWAV represented a new alphavirus species. Phylogenetic analyses and a linear discriminant analysis based on the dinucleotide ratios in various virus sequences indicated that MWAV is related to a mosquito-specific alphavirus distinct from other known mosquito-borne alphaviruses due to its inability to replicate in vertebrate cell lines. Further analyses of these novel alphaviruses will help to facilitate a greater understanding of the molecular determinants of host range restriction and the evolutionary relationships of alphaviruses.

ACS Style

Shiho Torii; Yasuko Orba; Bernard M. Hang’Ombe; Aaron S. Mweene; Yuji Wada; Paulina Duhita Anindita; Wallaya Phongphaew; Yongjin Qiu; Masahiro Kajihara; Akina Mori-Kajihara; Yoshiki Eto; Hayato Harima; Michihito Sasaki; Michael Carr; William W. Hall; Yuki Eshita; Takashi Abe; Hirofumi Sawa. Discovery of Mwinilunga alphavirus: A novel alphavirus in Culex mosquitoes in Zambia. Virus Research 2018, 250, 31 -36.

AMA Style

Shiho Torii, Yasuko Orba, Bernard M. Hang’Ombe, Aaron S. Mweene, Yuji Wada, Paulina Duhita Anindita, Wallaya Phongphaew, Yongjin Qiu, Masahiro Kajihara, Akina Mori-Kajihara, Yoshiki Eto, Hayato Harima, Michihito Sasaki, Michael Carr, William W. Hall, Yuki Eshita, Takashi Abe, Hirofumi Sawa. Discovery of Mwinilunga alphavirus: A novel alphavirus in Culex mosquitoes in Zambia. Virus Research. 2018; 250 ():31-36.

Chicago/Turabian Style

Shiho Torii; Yasuko Orba; Bernard M. Hang’Ombe; Aaron S. Mweene; Yuji Wada; Paulina Duhita Anindita; Wallaya Phongphaew; Yongjin Qiu; Masahiro Kajihara; Akina Mori-Kajihara; Yoshiki Eto; Hayato Harima; Michihito Sasaki; Michael Carr; William W. Hall; Yuki Eshita; Takashi Abe; Hirofumi Sawa. 2018. "Discovery of Mwinilunga alphavirus: A novel alphavirus in Culex mosquitoes in Zambia." Virus Research 250, no. : 31-36.

Journal article
Published: 25 December 2017 in Uirusu
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人獣共通感染症は自然界にその原因微生物が存在していることから,根絶することは不可能と考えられる.それ故,その発生を予測し,流行を防止する先回り戦略をとることが重要である.先回り戦略をとるために,病原微生物の起源と自然界における存続のメカニズム,伝播と侵入の経路および感染,発症と流行に関与する諸要因を明らかにする必要がある. 我々のチームは,検査体制,医療体制が不十分であり,感染症対策の支援を必要としているザンビア,およびインドネシアにおいて,野生動物が保有するウイルスを対象とした疫学研究を推進している.本稿では,両国との共同研究により得られた研究結果の内,DNAウイルスであるオルソポックスウイルス,ポリオーマウイルス,ヘルペスウイルスを対象とした研究について得られた結果を紹介する.

ACS Style

Hirofumi Sawa; Michihito Sasaki; Yasuko Orba. Discovery of DNA viruses in wildlife in Zambia and Indonesia. Uirusu 2017, 67, 151 -160.

AMA Style

Hirofumi Sawa, Michihito Sasaki, Yasuko Orba. Discovery of DNA viruses in wildlife in Zambia and Indonesia. Uirusu. 2017; 67 (2):151-160.

Chicago/Turabian Style

Hirofumi Sawa; Michihito Sasaki; Yasuko Orba. 2017. "Discovery of DNA viruses in wildlife in Zambia and Indonesia." Uirusu 67, no. 2: 151-160.

Journal article
Published: 01 August 2017 in Bioorganic & Medicinal Chemistry Letters
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NS2B-NS3 protease is an essential enzyme for the replication of dengue virus (DENV), which continues to be a serious threat to worldwide public health. We designed and synthesized a series of cyclic peptides mimicking the substrates of this enzyme, and assayed their activity against the DENV-2 NS2B-NS3 protease. The introduction of aromatic residues at the appropriate positions and conformational restriction generated the most promising cyclic peptide with an IC50 of 0.95μM against NS2B-NS3 protease. Cyclic peptides with proper positioning of additional arginines and aromatic residues exhibited antiviral activity against DENV. Furthermore, replacing the C-terminal amide bond of the polybasic amino acid sequence with an amino methylene moiety stabilized the cyclic peptides against hydrolysis by NS2B-NS3 protease, while maintaining their enzyme inhibitory activity and antiviral activity.

ACS Style

Youhei Takagi; Kouhei Matsui; Haruaki Nobori; Haruka Maeda; Akihiko Sato; Takeshi Kurosu; Yasuko Orba; Hirofumi Sawa; Kazunari Hattori; Kenichi Higashino; Yoshito Numata; Yutaka Yoshida. Discovery of novel cyclic peptide inhibitors of dengue virus NS2B-NS3 protease with antiviral activity. Bioorganic & Medicinal Chemistry Letters 2017, 27, 3586 -3590.

AMA Style

Youhei Takagi, Kouhei Matsui, Haruaki Nobori, Haruka Maeda, Akihiko Sato, Takeshi Kurosu, Yasuko Orba, Hirofumi Sawa, Kazunari Hattori, Kenichi Higashino, Yoshito Numata, Yutaka Yoshida. Discovery of novel cyclic peptide inhibitors of dengue virus NS2B-NS3 protease with antiviral activity. Bioorganic & Medicinal Chemistry Letters. 2017; 27 (15):3586-3590.

Chicago/Turabian Style

Youhei Takagi; Kouhei Matsui; Haruaki Nobori; Haruka Maeda; Akihiko Sato; Takeshi Kurosu; Yasuko Orba; Hirofumi Sawa; Kazunari Hattori; Kenichi Higashino; Yoshito Numata; Yutaka Yoshida. 2017. "Discovery of novel cyclic peptide inhibitors of dengue virus NS2B-NS3 protease with antiviral activity." Bioorganic & Medicinal Chemistry Letters 27, no. 15: 3586-3590.