1
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Frank JC, Song BH, Lee YM. Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis. Pathogens 2023; 12:pathogens12050715. [PMID: 37242385 DOI: 10.3390/pathogens12050715] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies.
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Affiliation(s)
- Jordan C Frank
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
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2
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Molecular Mechanism and Role of Japanese Encephalitis Virus Infection in Central Nervous System-Mediated Diseases. Viruses 2022; 14:v14122686. [PMID: 36560690 PMCID: PMC9781168 DOI: 10.3390/v14122686] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022] Open
Abstract
The Japanese encephalitis virus (JEV) is the most common cause of neurodegenerative disease in Southeast Asia and the Western Pacific region; approximately 1.15 billion people are at risk, and thousands suffer from permanent neurological disorders across Asian countries, with 10-15 thousand people dying each year. JEV crosses the blood-brain barrier (BBB) and forms a complex with receptors on the surface of neurons. GRP78, Src, TLR7, caveolin-1, and dopamine receptor D2 are involved in JEV binding and entry into the neurons, and these receptors also play a role in carcinogenic activity in cells. JEV binds to GRP78, a member of the HSP70 overexpressed on malignant cells to enter neurons, indicating a higher chance of JEV infection in cancer patients. However, JEV enters human brain microvascular endothelial cells via an endocytic pathway mediated by caveolae and the ezrin protein and also targets dopamine-rich areas for infection of the midbrain via altering dopamine levels. In addition, JEV complexed with CLEC5A receptor of macrophage cells is involved in the breakdown of the BBB and central nervous system (CNS) inflammation. CLEC5A-mediated infection is also responsible for the influx of cytokines into the CNS. In this review, we discuss the neuronal and macrophage surface receptors involved in neuronal death.
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Zhang QY, Liu SQ, Li XD, Li JQ, Zhang YN, Deng CL, Zhang HL, Li XF, Fang CX, Yang FX, Zhang B, Xu Y, Ye HQ. Sequence duplication in 3' UTR modulates virus replication and virulence of Japanese encephalitis virus. Emerg Microbes Infect 2021; 11:123-135. [PMID: 34877923 PMCID: PMC8725919 DOI: 10.1080/22221751.2021.2016354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Japanese encephalitis virus (JEV), an important neurotropic pathogen, belongs to the genus Flavivirus of the family Flaviviridae and has caused huge threat to public health. It is still obscure regarding the functions of stem-loop (SL) and dumbbell (DB) domains of JEV 3' UTR in viral replication and virulence. In the current study, using the infectious clone of JEV SA14 strain as a backbone, we constructed a series of deletion mutants of 3' UTR to investigate their effects on virus replication. The results showed that partial deletions within SL or DB domain had no apparent effects on virus replication in both mammalian (BHK-21) and mosquito (C6/36) cells, suggesting that they were not involved in viral host-specific replication. However, the entire SL domain deletion (ΔVR) significantly reduced virus replication in both cell lines, indicating the important role of the complete SL domain in virus replication. The revertant of ΔVR mutant virus was obtained by serial passage in BHK-21 cells that acquired a duplication of DB domain (DB-dup) in the 3' UTR, which greatly restored virus replication as well as the capability to produce the subgenomic flavivirus RNAs (sfRNAs). Interestingly, the DB-dup mutant virus was highly attenuated in C57BL/6 mice despite replicating similar to WT JEV. These findings demonstrate the significant roles of the duplicated structures in 3' UTR in JEV replication and provide a novel strategy for the design of live-attenuated vaccines.
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Affiliation(s)
- Qiu-Yan Zhang
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China.,The Joint Center of Translational Precision Medicine, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Si-Qing Liu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Xiao-Dan Li
- School of Medicine, Hunan Normal University, Changsha, People's Republic of China
| | - Jia-Qi Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Ya-Nan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Cheng-Lin Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Hong-Lei Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, People's Republic of China
| | - Xu-Fang Li
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China
| | - Chun-Xiao Fang
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China
| | - Feng-Xia Yang
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China
| | - Bo Zhang
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China.,The Joint Center of Translational Precision Medicine, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, People's Republic of China.,Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Yi Xu
- The Joint Center of Translational Precision Medicine, Department of Infectious Diseases, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou, People's Republic of China.,The Joint Center of Translational Precision Medicine, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Han-Qing Ye
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, People's Republic of China
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Xu P, Tong W, Chen YM. FUSE binding protein FUBP3 is a potent regulator in Japanese encephalitis virus infection. Virol J 2021; 18:224. [PMID: 34794468 PMCID: PMC8600714 DOI: 10.1186/s12985-021-01697-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/10/2021] [Indexed: 12/01/2022] Open
Abstract
Background The JEV genome is a positive-sense RNA with a highly structured capped 5′UTR, 3′UTR and a large open reading frame. 3′UTR is the untranslated region of flavivirus and has various important functions during viral replication, such as translation, replication and encapsidation. During viral replication, the 3′UTR interacts with viral proteins and host proteins and is required for viral RNA replication and translocation. Methods The expression level of FUBP3 was knocked down by siRNA and Flag-tagged FUBP3 overexpression plasmid was constructed for overexpression. BHK-21 cells were cultured and infected with JEV to investigate the functional role of FUBP3 in the viral infection cycle. Subcellular localization of FUBP3 and viral replication complexes was observed by dual immunofluorescence staining. Results Four host proteins were specifically associated with the 3′UTR of JEV, and FUBP3 was selected to further investigate its potential functional role in the JEV infection cycle. Knockdown of FUBP3 protein resulted in a significant decrease in JEV viral titer, whereas ectopic overexpression of FUBP3 resulted in increased JE viral infectivity. In cells stably knocked down for FUBP3 and then infected with JEV, we found almost no detectable viral NS5 protein. In contrast, when cells stably knocking-down of FUBP3 overexpressed FUBP3, we found a significant increase in viral RNA production over time compared to controls. We also demonstrated that FUBP3 re-localized in the cytoplasm after infection with JEV and co-localized with viral proteins. Exogenous overexpression of FUBP3 was also shown to be located in the JE replication complex and to assist viral replication after JEV infection. Conclusions The overall results suggest that FUBP3 regulates RNA replication of JEV and promotes subsequent viral translation and viral particle production.
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Affiliation(s)
- Peng Xu
- Xiangyang No.1 People's HospitalHubei University of Medicine, Xiangyang, Hubei Province, China
| | - Wei Tong
- Department of Clinical Laboratory, Xiangyang No.1 People's Hospital, Hubei University of Medicine, Xiangyang, China
| | - Young-Mao Chen
- Bachelor Degree Program in Marine Biotechnology, College of Life Sciences, National Taiwan Ocean University, Keelung, 20224, Taiwan. .,Center of Excellence for the Oceans and Matsu Marine Research Center, National Taiwan Ocean University, Keelung, 20224, Taiwan.
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Zhang YN, Li N, Zhang QY, Liu J, Zhan SL, Gao L, Zeng XY, Yu F, Zhang HQ, Li XD, Deng CL, Shi PY, Yuan ZM, Yuan SP, Ye HQ, Zhang B. Rational design of West Nile virus vaccine through large replacement of 3' UTR with internal poly(A). EMBO Mol Med 2021; 13:e14108. [PMID: 34351689 PMCID: PMC8422072 DOI: 10.15252/emmm.202114108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 11/29/2022] Open
Abstract
The genus Flavivirus comprises numerous emerging and re-emerging arboviruses causing human illness. Vaccines are the best approach to prevent flavivirus diseases. But pathogen diversities are always one of the major hindrances for timely development of new vaccines when confronting unpredicted flavivirus outbreaks. We used West Nile virus (WNV) as a model to develop a new live-attenuated vaccine (LAV), WNV-poly(A), by replacing 5' portion (corresponding to SL and DB domains in WNV) of 3'-UTR with internal poly(A) tract. WNV-poly(A) not only propagated efficiently in Vero cells, but also was highly attenuated in mouse model. A single-dose vaccination elicited robust and long-lasting immune responses, conferring full protection against WNV challenge. Such "poly(A)" vaccine strategy may be promising for wide application in the development of flavivirus LAVs because of its general target regions in flaviviruses.
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Affiliation(s)
- Ya-Nan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Na Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Qiu-Yan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Jing Liu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Shun-Li Zhan
- Beijing Shunlei Biotechnology Co. Ltd., Beijing, China
| | - Lei Gao
- Beijing Shunlei Biotechnology Co. Ltd., Beijing, China
| | - Xiang-Yue Zeng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Fang Yu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Hong-Qing Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Xiao-Dan Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Cheng-Lin Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Pei-Yong Shi
- University of Texas Medical Branch, Galveston, TX, USA
| | - Zhi-Ming Yuan
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | | | - Han-Qing Ye
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Bo Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
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Xing J, Zhang Y, Lin Z, Liu L, Xu Q, Liang J, Yuan Z, Huang C, Liao M, Qi W. 3'UTR SL-IV and DB1 Regions Contribute to Japanese Encephalitis Virus Replication and Pathogenicity. Front Vet Sci 2021; 8:703147. [PMID: 34409089 PMCID: PMC8366024 DOI: 10.3389/fvets.2021.703147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/07/2021] [Indexed: 11/29/2022] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus that causes fatal neurological disease in humans, is one of the most important emerging pathogens of public health significance. JEV is maintained in an enzootic cycle and causes reproductive failure in pigs. Notably, the shift in JEV genotypes is not fully protected by existing vaccines, so the development of a candidate vaccine is urgently needed. In this study, we compared pathogenicity between Japanese encephalitis virus SA14 and BJB (isolated from humans in the 1970s) strains. We found that the BJB strain was attenuated in mice and that there was no case fatality rate. The growth rate of BJB was higher than SA14 virus in BHK-21 cells. Based on the sequence alignment of the viral genome between the SA14 and BJB virus strains, some mutations at sites 248, 254, 258, and 307 were observed in the 3′ untranslated region (3′UTR). The 3′UTR of JEV plays a very important role in the viral life cycle. Furthermore, using a reverse genetic system, we conducted and rescued the parental JEV strain SA14 (T248, A254, and A258) and the mutant virus rSA14-3′UTRmut (T248C, A254G, A258G, and 307G). Through an analysis of the RNA secondary structure model of the 3′UTR, we discovered that the mutations of T248C, A254G, and A258G reduced the apiculus ring and increased the lateral ring significantly in the stem-loop structures IV (SL-IV) structure region of 3′UTR. Moreover, the insertion of 307G added a ring to the dumbbell structure 1 (DB1) structure region. Strikingly, these RNA secondary structure changes in 3′UTR of rSA14-3′UTRmut increased viral negative chain RNA production and enhanced the replication ability of the virus in BHK-21 cells. However, in vivo mouse experiments illustrated that the rSA14-3′UTRmut virus significantly decreased the neurovirulence of JEV. These results affirmed that the JEV SL-IV and DB1 regions play an important role in viral proliferation and pathogenicity. Taken together, we complement the study of RNA element function in the 3′UTR region of JEV by providing a new target for the rational design of live attenuated candidate vaccines and the increase of virus production.
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Affiliation(s)
- Jinchao Xing
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Youyue Zhang
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Ziying Lin
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Lele Liu
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Qiang Xu
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Jiaqi Liang
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Zhaoxia Yuan
- College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Cuiqin Huang
- The Key Laboratory of Fujian Animal Diseases Control, Longyan University, Longyan, China
| | - Ming Liao
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Wenbao Qi
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
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Muñoz-Chimeno M, Cenalmor A, Garcia-Lugo MA, Hernandez M, Rodriguez-Lazaro D, Avellon A. Proline-Rich Hypervariable Region of Hepatitis E Virus: Arranging the Disorder. Microorganisms 2020; 8:microorganisms8091417. [PMID: 32942608 PMCID: PMC7564002 DOI: 10.3390/microorganisms8091417] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/21/2020] [Accepted: 09/11/2020] [Indexed: 12/15/2022] Open
Abstract
The hepatitis E virus (HEV) hypervariable region (HVR) presents the highest divergence of the entire HEV genome. It is characteristically rich in proline, and so is also known as the “polyproline region” (PPR). HEV genotype 3 (HEV-3) exhibits different PPR lengths due to insertions, PPR and/or RNA-dependent RNA polymerase (RdRp) duplications and deletions. A total of 723 PPR-HEV sequences were analyzed, of which 137 HEV-3 sequences were obtained from clinical specimens (from acute and chronic infection) by Sanger sequencing. Eight swine stool/liver samples were also analyzed. N- and C-terminal fragments were confirmed as being conserved, but they harbored differences between genotypes and were not proline-plentiful regions. The genuine PPR is the intermediate region between them. HEV-3 PPR contains a higher percentage (30.4%) of prolines than other genotypes. We describe for the first time: (1) the specific placement of HEV-3 PPR rearrangements in sites 1 to 14 of the PPR, noting that duplications are more frequently attached to sites 11 and 12 (AAs 74–79 and 113–118, respectively); (2) the cadence of repetitions follows a circular-like pattern of blocks A to J, with F, G, H, and I being the most frequent; (3) a previously unreported insertion homologous to apolipoprotein C1; and (4) the increase in frequency of potential N-glycosylation sites and differences in AAs composition related to duplications.
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Affiliation(s)
- Milagros Muñoz-Chimeno
- Hepatitis Unit, National Center of Microbiology, Carlos III Institute of Health, 28220 Madrid, Spain; (M.M.-C.); (A.C.); (M.A.G.-L.)
| | - Alejandro Cenalmor
- Hepatitis Unit, National Center of Microbiology, Carlos III Institute of Health, 28220 Madrid, Spain; (M.M.-C.); (A.C.); (M.A.G.-L.)
| | - Maira Alejandra Garcia-Lugo
- Hepatitis Unit, National Center of Microbiology, Carlos III Institute of Health, 28220 Madrid, Spain; (M.M.-C.); (A.C.); (M.A.G.-L.)
| | - Marta Hernandez
- Laboratorio de Biología Molecular y Microbiología, Instituto Tecnológico Agrario de Castilla y León (ITACyL), 47071 Valladolid, Spain;
- Microbiology Division, Faculty of Sciences, University of Burgos, 09001 Burgos, Spain;
| | | | - Ana Avellon
- Hepatitis Unit, National Center of Microbiology, Carlos III Institute of Health, 28220 Madrid, Spain; (M.M.-C.); (A.C.); (M.A.G.-L.)
- CIBER Epidemiology and Public Health, 28029 Madrid, Spain
- Correspondence:
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8
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Yun SI, Song BH, Woolley ME, Frank JC, Julander JG, Lee YM. Development, Characterization, and Application of Two Reporter-Expressing Recombinant Zika Viruses. Viruses 2020; 12:v12050572. [PMID: 32456014 PMCID: PMC7290298 DOI: 10.3390/v12050572] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 12/20/2022] Open
Abstract
Zika virus (ZIKV), a mosquito-borne transplacentally transmissible flavivirus, is an enveloped virus with an ~10.8 kb plus-strand RNA genome that can cause neurological disease. To facilitate the identification of potential antivirals, we developed two reporter-expressing ZIKVs, each capable of expressing an enhanced green fluorescent protein or an improved luminescent NanoLuc luciferase. First, a full-length functional ZIKV cDNA clone was engineered as a bacterial artificial chromosome, with each reporter gene under the cap-independent translational control of a cardiovirus-derived internal ribosome entry site inserted downstream of the single open reading frame of the viral genome. Two reporter-expressing ZIKVs were then generated by transfection of ZIKV-susceptible BHK-21 cells with infectious RNAs derived by in vitro run-off transcription from the respective cDNAs. As compared to the parental virus, the two reporter-expressing ZIKVs grew to lower titers with slower growth kinetics and formed smaller foci; however, they displayed a genome-wide viral protein expression profile identical to that of the parental virus, except for two previously unrecognized larger forms of the C and NS1 proteins. We then used the NanoLuc-expressing ZIKV to assess the in vitro antiviral activity of three inhibitors (T-705, NITD-008, and ribavirin). Altogether, our reporter-expressing ZIKVs represent an excellent molecular tool for the discovery of novel antivirals.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
| | - Michael E. Woolley
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
| | - Jordan C. Frank
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
| | - Justin G. Julander
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
- Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA; (S.-I.Y.); (B.-H.S.); (M.E.W.); (J.C.F.); (J.G.J.)
- Veterinary Diagnostics and Infectious Diseases, Utah Science Technology and Research, Utah State University, Logan, UT 84341, USA
- Correspondence: ; Tel.: +1-435-797-9667
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9
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Asian Zika Virus Isolate Significantly Changes the Transcriptional Profile and Alternative RNA Splicing Events in a Neuroblastoma Cell Line. Viruses 2020; 12:v12050510. [PMID: 32380717 PMCID: PMC7290316 DOI: 10.3390/v12050510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/27/2020] [Indexed: 12/18/2022] Open
Abstract
The alternative splicing of pre-mRNAs expands a single genetic blueprint to encode multiple, functionally diverse protein isoforms. Viruses have previously been shown to interact with, depend on, and alter host splicing machinery. The consequences, however, incited by viral infection on the global alternative slicing (AS) landscape are under-appreciated. Here, we investigated the transcriptional and alternative splicing profile of neuronal cells infected with a contemporary Puerto Rican Zika virus (ZIKVPR) isolate, an isolate of the prototypical Ugandan ZIKV (ZIKVMR), and dengue virus 2 (DENV2). Our analyses revealed that ZIKVPR induced significantly more differential changes in expressed genes compared to ZIKVMR or DENV2, despite all three viruses showing equivalent infectivity and viral RNA levels. Consistent with the transcriptional profile, ZIKVPR induced a higher number of alternative splicing events compared to ZIKVMR or DENV2, and gene ontology analyses highlighted alternative splicing changes in genes associated with mRNA splicing. In summary, we show that ZIKV affects cellular RNA homeostasis not only at the transcriptional levels but also through the alternative splicing of cellular transcripts. These findings could provide new molecular insights into the neuropathologies associated with this virus.
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10
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Wang Y, Yang ZY, Tian YP, Geng C, Yuan XF, Li XD. Role of Tobacco vein banding mosaic virus 3'-UTR on virus systemic infection in tobacco. Virology 2019; 527:38-46. [PMID: 30453210 DOI: 10.1016/j.virol.2018.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 11/30/2022]
Abstract
To investigate the role of Tobacco vein banding mosaic virus (TVBMV) 3'-UTR in virus systemic infection, three types of deletions were introduced into TVBMV infectious clone pCaTVBMV-GFP. Mutants with deletions at the nucleotide position 8-42, 43-141, or 163-174 in the 3'-UTR failed to cause systemic infection in N. benthamiana plants. Other deletion mutants caused delayed systemic infection and milder vein clearing and mosaic symptoms. Most progeny mutant virus had acquired nucleotides, similar to or different from the deleted nucleotide sequences, after a single passage in the host plant. Nucleotides at the position 8-42 near the 5'-terminus of TVBMV 3'-UTR could form a stem-loop (SL) like structure which was crucial for TVBMV systemic movement in tobacco. We proposed that this SL like structure, and thus 3'-UTR, has an essential role in TVBMV systemic infection.
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Affiliation(s)
- Ying Wang
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University; Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an 271018, PR China; Department of Microbiology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, PR China; College of Life Sciences, Linyi University, Linyi 276005, PR China
| | - Zheng-You Yang
- Department of Microbiology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, PR China
| | - Yan-Ping Tian
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University; Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an 271018, PR China
| | - Chao Geng
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University; Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an 271018, PR China
| | - Xue-Feng Yuan
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University; Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an 271018, PR China.
| | - Xiang-Dong Li
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University; Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an 271018, PR China.
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11
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Liu X, Liu Y, Zhang Q, Zhang B, Xia H, Yuan Z. Homologous RNA secondary structure duplications in 3′ untranslated region influence subgenomic RNA production and replication of dengue virus. Virology 2018; 524:114-126. [DOI: 10.1016/j.virol.2018.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/18/2018] [Accepted: 08/21/2018] [Indexed: 10/28/2022]
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12
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Contemporary Circulating Enterovirus D68 Strains Have Acquired the Capacity for Viral Entry and Replication in Human Neuronal Cells. mBio 2018; 9:mBio.01954-18. [PMID: 30327438 PMCID: PMC6191546 DOI: 10.1128/mbio.01954-18] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Since the EV-D68 outbreak during the summer of 2014, evidence of a causal link to a type of limb paralysis (AFM) has been mounting. In this article, we describe a neuronal cell culture model (SH-SY5Y cells) in which a subset of contemporary 2014 outbreak strains of EV-D68 show infectivity in neuronal cells, or neurotropism. We confirmed the difference in neurotropism in vitro using primary human neuron cell cultures and in vivo with a mouse paralysis model. Using the SH-SY5Y cell model, we determined that a barrier to viral entry is at least partly responsible for neurotropism. SH-SY5Y cells may be useful in determining if specific EV-D68 genetic determinants are associated with neuropathogenesis, and replication in this cell line could be used as rapid screening tool for identification of neurotropic EV-D68 strains. This may assist with better understanding of pathogenesis and epidemiology and with the development of potential therapies. Enterovirus D68 (EV-D68) has historically been associated with respiratory illnesses. However, in the summers of 2014 and 2016, EV-D68 outbreaks coincided with a spike in polio-like acute flaccid myelitis/paralysis (AFM/AFP) cases. This raised concerns that EV-D68 could be the causative agent of AFM during these recent outbreaks. To assess the potential neurotropism of EV-D68, we utilized the neuroblastoma-derived neuronal cell line SH-SY5Y as a cell culture model to determine if differential infection is observed for different EV-D68 strains. In contrast to HeLa and A549 cells, which support viral infection of all EV-D68 strains tested, SH-SY5Y cells only supported infection by a subset of contemporary EV-D68 strains, including isolates from the 2014 outbreak. Viral replication and infectivity in SH-SY5Y were assessed using multiple assays: virus production, cytopathic effects, cellular ATP release, and VP1 capsid protein production. Similar differential neurotropism was also observed in differentiated SH-SY5Y cells, primary human neuron cultures, and a mouse paralysis model. Using the SH-SY5Y cell culture model, we determined that barriers to viral binding and entry were at least partly responsible for the differential infectivity phenotype. Transfection of genomic RNA into SH-SY5Y generated virions for all EV-D68 isolates, but only a single round of replication was observed from strains that could not directly infect SH-SY5Y. In addition to supporting virus replication and other functional studies, this cell culture model may help identify the signatures of virulence to confirm epidemiological associations between EV-D68 strains and AFM and allow for the rapid identification and characterization of emerging neurotropic strains.
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Early Events in Japanese Encephalitis Virus Infection: Viral Entry. Pathogens 2018; 7:pathogens7030068. [PMID: 30104482 PMCID: PMC6161159 DOI: 10.3390/pathogens7030068] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 12/15/2022] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne zoonotic flavivirus, is an enveloped positive-strand RNA virus that can cause a spectrum of clinical manifestations, ranging from mild febrile illness to severe neuroinvasive disease. Today, several killed and live vaccines are available in different parts of the globe for use in humans to prevent JEV-induced diseases, yet no antivirals are available to treat JEV-associated diseases. Despite the progress made in vaccine research and development, JEV is still a major public health problem in southern, eastern, and southeastern Asia, as well as northern Oceania, with the potential to become an emerging global pathogen. In viral replication, the entry of JEV into the cell is the first step in a cascade of complex interactions between the virus and target cells that is required for the initiation, dissemination, and maintenance of infection. Because this step determines cell/tissue tropism and pathogenesis, it is a promising target for antiviral therapy. JEV entry is mediated by the viral glycoprotein E, which binds virions to the cell surface (attachment), delivers them to endosomes (endocytosis), and catalyzes the fusion between the viral and endosomal membranes (membrane fusion), followed by the release of the viral genome into the cytoplasm (uncoating). In this multistep process, a collection of host factors are involved. In this review, we summarize the current knowledge on the viral and cellular components involved in JEV entry into host cells, with an emphasis on the initial virus-host cell interactions on the cell surface.
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14
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Yun SI, Song BH, Frank JC, Julander JG, Olsen AL, Polejaeva IA, Davies CJ, White KL, Lee YM. Functional Genomics and Immunologic Tools: The Impact of Viral and Host Genetic Variations on the Outcome of Zika Virus Infection. Viruses 2018; 10:v10080422. [PMID: 30103523 PMCID: PMC6116225 DOI: 10.3390/v10080422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/13/2022] Open
Abstract
Zika virus (ZIKV) causes no-to-mild symptoms or severe neurological disorders. To investigate the importance of viral and host genetic variations in determining ZIKV infection outcomes, we created three full-length infectious cDNA clones as bacterial artificial chromosomes for each of three spatiotemporally distinct and genetically divergent ZIKVs: MR-766 (Uganda, 1947), P6-740 (Malaysia, 1966), and PRVABC-59 (Puerto Rico, 2015). Using the three molecularly cloned ZIKVs, together with 13 ZIKV region-specific polyclonal antibodies covering nearly the entire viral protein-coding region, we made three conceptual advances: (i) We created a comprehensive genome-wide portrait of ZIKV gene products and their related species, with several previously undescribed gene products identified in the case of all three molecularly cloned ZIKVs. (ii) We found that ZIKV has a broad cell tropism in vitro, being capable of establishing productive infection in 16 of 17 animal cell lines from 12 different species, although its growth kinetics varied depending on both the specific virus strain and host cell line. More importantly, we identified one ZIKV-non-susceptible bovine cell line that has a block in viral entry but fully supports the subsequent post-entry steps. (iii) We showed that in mice, the three molecularly cloned ZIKVs differ in their neuropathogenicity, depending on the particular combination of viral and host genetic backgrounds, as well as in the presence or absence of type I/II interferon signaling. Overall, our findings demonstrate the impact of viral and host genetic variations on the replication kinetics and neuropathogenicity of ZIKV and provide multiple avenues for developing and testing medical countermeasures against ZIKV.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
| | - Byung-Hak Song
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
| | - Jordan C Frank
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
| | - Justin G Julander
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
- Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA.
| | - Aaron L Olsen
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
| | - Irina A Polejaeva
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
- Veterinary Diagnostics and Infectious Diseases, Utah Science Technology and Research, Utah State University, Logan, UT 84341, USA.
| | - Christopher J Davies
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
- Veterinary Diagnostics and Infectious Diseases, Utah Science Technology and Research, Utah State University, Logan, UT 84341, USA.
| | - Kenneth L White
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
- Veterinary Diagnostics and Infectious Diseases, Utah Science Technology and Research, Utah State University, Logan, UT 84341, USA.
| | - Young-Min Lee
- Department of Animal Dairy and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA.
- Veterinary Diagnostics and Infectious Diseases, Utah Science Technology and Research, Utah State University, Logan, UT 84341, USA.
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15
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Chen YS, Fan YH, Tien CF, Yueh A, Chang RY. The conserved stem-loop II structure at the 3' untranslated region of Japanese encephalitis virus genome is required for the formation of subgenomic flaviviral RNA. PLoS One 2018; 13:e0201250. [PMID: 30048535 PMCID: PMC6062100 DOI: 10.1371/journal.pone.0201250] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 07/11/2018] [Indexed: 01/02/2023] Open
Abstract
Flaviviruses accumulate abundant subgenomic RNA (sfRNA) in infected cells. It has been reported that sfRNA results from stalling of host 5’-to-3’ exoribonuclease XRN1 at the highly structured RNA of the 3’ untranslated region (UTR). Although XRN1 digestion of a 3’-terminal 800-nt RNA could stall at a position to generate the sfRNA in vitro, we found that knocking out XRN1 had no effect on the accumulation of sfRNA in Japanese encephalitis virus (JEV) infected cells. Mutagenesis studies revealed that the stemloop II (SLII) at the 3’ UTR is required for the accumulation of sfRNA. According to the results of an in vitro RNA-dependent RNA polymerase (RdRp) assay, the (-)10431-10566 RNA fragment, containing the putative promoter on the antigenome for the sfRNA transcription, binds to RdRp protein and exhibits a strong promoter activity. Taken together, our results indicate that the JEV sfRNA could be transcribed initially and then be trimmed by XRN1 or other unidentified exoribonucleases.
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Affiliation(s)
- Yi-Shiuan Chen
- Department of Life Science, National Dong Hwa University, Hualien, Taiwan, ROC
| | - Yi-Hsin Fan
- Department of Life Science, National Dong Hwa University, Hualien, Taiwan, ROC
| | - Chih-Feng Tien
- Department of Life Science, National Dong Hwa University, Hualien, Taiwan, ROC
| | - Andrew Yueh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli, Taiwan, ROC
| | - Ruey-Yi Chang
- Department of Life Science, National Dong Hwa University, Hualien, Taiwan, ROC
- * E-mail:
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16
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Genomic changes in an attenuated genotype I Japanese encephalitis virus and comparison with virulent parental strain. Virus Genes 2018; 54:424-431. [PMID: 29605839 DOI: 10.1007/s11262-018-1559-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 03/29/2018] [Indexed: 10/17/2022]
Abstract
Genotype I Japanese encephalitis virus (JEV) strain SCYA201201 was previously isolated from brain tissues of aborted piglets. In this study, we obtained an attenuated SCYA201201-0901 strain by serial passage of strain SCYA201201-1 in Syrian baby hamster kidney cells, combined with multiple plaque purifications and selection for virulence in mice. We investigated the genetic changes associated with attenuation by comparing the entire genomes of SCYA201201-0901 and SCYA201201-1. Sequence comparisons identified 14 common amino acid substitutions in the coding region, with two nucleotide point mutations in the 5'-untranslated region (UTR) and another three in the 3'-UTR, which differed between the attenuated and virulent strains. In addition, a total of 13 silent nucleotide mutations were found after attenuation. These substitutions, alone or in combination, may be responsible for the attenuated phenotype of the SCYA201201-0901 strain in mice. This information will contribute to our understanding of attenuation and of the molecular basis of virulence in genotype I strains such as SCYA201201-0901, as well as aiding the development of safer JEV vaccines.
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17
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Yun SI, Lee YM. Zika virus: An emerging flavivirus. J Microbiol 2017; 55:204-219. [PMID: 28243937 DOI: 10.1007/s12275-017-7063-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 02/15/2017] [Indexed: 01/18/2023]
Abstract
Zika virus (ZIKV) is a previously little-known flavivirus closely related to Japanese encephalitis, West Nile, dengue, and yellow fever viruses, all of which are primarily transmitted by blood-sucking mosquitoes. Since its discovery in Uganda in 1947, ZIKV has continued to expand its geographic range, from equatorial Africa and Asia to the Pacific Islands, then further afield to South and Central America and the Caribbean. Currently, ZIKV is actively circulating not only in much of Latin America and its neighbors but also in parts of the Pacific Islands and Southeast Asia. Although ZIKV infection generally causes only mild symptoms in some infected individuals, it is associated with a range of neuroimmunological disorders, including Guillain-Barré syndrome, meningoencephalitis, and myelitis. Recently, maternal ZIKV infection during pregnancy has been linked to neonatal malformations, resulting in various degrees of congenital abnormalities, microcephaly, and even abortion. Despite its emergence as an important public health problem, however, little is known about ZIKV biology, and neither vaccine nor drug is available to control ZIKV infection. This article provides a brief introduction to ZIKV with a major emphasis on its molecular virology, in order to help facilitate the development of diagnostics, therapeutics, and vaccines.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, 84322-4815, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, 84322-4815, USA. .,Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, UT, 84322-4815, USA.
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18
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Yuan L, Wu R, Liu H, Wen X, Huang X, Wen Y, Ma X, Yan Q, Huang Y, Zhao Q, Cao S. The NS3 and NS4A genes as the targets of RNA interference inhibit replication of Japanese encephalitis virus in vitro and in vivo. Gene 2016; 594:183-189. [PMID: 27593564 DOI: 10.1016/j.gene.2016.08.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/10/2016] [Accepted: 08/31/2016] [Indexed: 02/06/2023]
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that can cause acute encephalitis with a high fatality rate. RNA interference (RNAi) is a powerful tool to silence gene expression and a potential therapy for virus infection. In this study, the antiviral ability of eight shRNA expression plasmids targeting different sites of the NS3 and NS4A genes of JEV was determined in BHK21 cells and mice. The pGP-NS3-3 and pGP-NS4A-4 suppressed 93.9% and 82.0% of JEV mRNA in cells, respectively. The virus titer in cells was reduced approximately 950-fold by pretreating with pGP-NS3-4, and 640-fold by pretreating with pGP-NS4A-4. The results of western blot and immunofluorescence analysis showed JEV E protein and viral load in cells were remarkably inhibited by shRNA expression plasmids. The viral load in brains of mice pretreated with pGP-NS3-4 or pGP-NS4A-4 were reduced approximately 2400-fold and 800-fold, respectively, and the survival rate of mice challenged with JEV were 70% and 50%, respectively. However, the antiviral ability of shRNA expression plasmids was decreased over time. This study indicates that RNAi targeting of the NS3 and NS4A genes of JEV can sufficiently inhibit the replication of JEV in vitro and in vivo, and NS3 and NS4A genes might be potential targets of molecular therapy for JEV infection.
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Affiliation(s)
- Lei Yuan
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Rui Wu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Hanyang Liu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Xintian Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Xiaobo Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Yiping Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Xiaoping Ma
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Qigui Yan
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Yong Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China
| | - Qin Zhao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Sanjie Cao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu 611130, China.
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19
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Lim YS, Ngo HTT, Lee J, Son K, Park EM, Hwang SB. ADP-ribosylation Factor-related Protein 1 Interacts with NS5A and Regulates Hepatitis C Virus Propagation. Sci Rep 2016; 6:31211. [PMID: 27550144 PMCID: PMC4994002 DOI: 10.1038/srep31211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/08/2016] [Indexed: 12/12/2022] Open
Abstract
The life cycle of hepatitis C virus (HCV) is tightly coupled to the lipid metabolism of host cells. In order to identify host factors involved in HCV propagation, we have previously screened a small interfering RNA (siRNA) library targeting host genes that control lipid metabolism and lipid droplet (LD) formation using cell culture-grown HCV (HCVcc)-infected cells. In this study, we selected and characterized the gene encoding ADP-ribosylation factor-related protein 1 (ARFRP1). ARFRP1 is essential for LD growth and is involved in the regulation of lipolysis. siRNA-mediated knockdown of ARFRP1 significantly inhibited HCV replication in both subgenomic replicon cells and HCVcc-infected cells. ARFRP1 interacted with NS5A and NS5A partially colocalized with LD. Silencing of ARFRP1 abrogated HCV-induced LD growth and viral protein expressions. Moreover, ARFRP1 recruited synaptosomal-associated protein 23 (SNAP23) to sites in close proximity to LDs in HCV-infected cells. Silencing of ARFRP1 ablated relocalization of SNAP23 to LD. These data indicate that HCV regulates ARFRP1 for LD growth to facilitate viral propagation and thus ARFRP1 may be a potential target for antiviral therapy.
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Affiliation(s)
- Yun-Sook Lim
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
| | - Huong T T Ngo
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
| | - Jihye Lee
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
| | - Kidong Son
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
| | - Eun-Mee Park
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea.,Korea National Institute of Health, Cheongwon-gun, South Korea
| | - Soon B Hwang
- National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea
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20
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Yun SI, Song BH, Polejaeva IA, Davies CJ, White KL, Lee YM. Comparison of the live-attenuated Japanese encephalitis vaccine SA14-14-2 strain with its pre-attenuated virulent parent SA14 strain: similarities and differences in vitro and in vivo. J Gen Virol 2016; 97:2575-2591. [PMID: 27498826 DOI: 10.1099/jgv.0.000574] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Japanese encephalitis virus (JEV) is the main cause of acute viral encephalitis, primarily affecting children and young adults in the Asia-Pacific region. JEV is a vaccine-preventable pathogen, with four types of JE vaccine licensed in different regions of the world. To date, the most common JEV strain used in vaccine development and production is SA14-14-2, an attenuated strain derived from its wild-type parental strain SA14. In this study, we directly compared the phenotypic and genotypic characteristics of SA14 and SA14-14-2 to determine the biological and genetic properties associated with their differential virulence. In susceptible BHK-21 cells, SA14-14-2 grew slightly more slowly and formed smaller plaques than SA14, but unlike SA14, it showed almost no expression of the viral protein NS1', the product of a conserved predicted RNA pseudoknot-mediated ribosomal frameshift. In weanling ICR mice, SA14-14-2 was highly attenuated in terms of both neuroinvasiveness and neurovirulence, with its median lethal doses invariably over five logs higher than those of SA14 when inoculated intramuscularly and intracerebrally. Interestingly, the neurovirulence of SA14-14-2 was dependent on mouse age, with the 1- to 7-day-old mice being highly susceptible and the 14- to 21-day-old mice becoming resistant to intracerebral inoculation. At the genome level, SA14-14-2 differed from SA14 by 57 nucleotides, including one silent G-to-A substitution at position 3599 within the predicted RNA pseudoknot for NS1' synthesis; of the 57 differences, 25 resulted in amino acid substitutions. Our data pave the way for the development of new genetically modified JE vaccines.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Irina A Polejaeva
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Christopher J Davies
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Kenneth L White
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322, USA
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21
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RNA Structure Duplications and Flavivirus Host Adaptation. Trends Microbiol 2016; 24:270-283. [PMID: 26850219 DOI: 10.1016/j.tim.2016.01.002] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/04/2016] [Accepted: 01/08/2016] [Indexed: 01/11/2023]
Abstract
Flaviviruses include a highly diverse group of arboviruses with a global distribution and a high human disease burden. Most flaviviruses cycle between insects and vertebrate hosts; thus, they are obligated to use different cellular machinery for their replication and mount different mechanisms to evade specific antiviral responses. In addition to coding for viral proteins, the viral genome contains signals in RNA structures that govern the amplification of viral components and participate in triggering or evading antiviral responses. In this review, we focused on new information about host-specific functions of RNA structures present in the 3' untranslated region (3' UTR) of flavivirus genomes. Models and conservation patterns of RNA elements of distinct flavivirus ecological groups are revised. An intriguing feature of the 3' UTR of insect-borne flavivirus genomes is the conservation of complex RNA structure duplications. Here, we discuss new hypotheses of how these RNA elements specialize for replication in vertebrate and invertebrate hosts, and present new ideas associating the significance of RNA structure duplication, small subgenomic flavivirus RNA formation, and host adaptation.
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Yun SI, Song BH, Kim JK, Lee YM. Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses. J Vis Exp 2015:e53164. [PMID: 26780115 PMCID: PMC4780872 DOI: 10.3791/53164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Reverse genetics, an approach to rescue infectious virus entirely from a cloned cDNA, has revolutionized the field of positive-strand RNA viruses, whose genomes have the same polarity as cellular mRNA. The cDNA-based reverse genetics system is a seminal method that enables direct manipulation of the viral genomic RNA, thereby generating recombinant viruses for molecular and genetic studies of both viral RNA elements and gene products in viral replication and pathogenesis. It also provides a valuable platform that allows the development of genetically defined vaccines and viral vectors for the delivery of foreign genes. For many positive-strand RNA viruses such as Japanese encephalitis virus (JEV), however, the cloned cDNAs are unstable, posing a major obstacle to the construction and propagation of the functional cDNA. Here, the present report describes the strategic considerations in creating and amplifying a genetically stable full-length infectious JEV cDNA as a bacterial artificial chromosome (BAC) using the following general experimental procedures: viral RNA isolation, cDNA synthesis, cDNA subcloning and modification, assembly of a full-length cDNA, cDNA linearization, in vitro RNA synthesis, and virus recovery. This protocol provides a general methodology applicable to cloning full-length cDNA for a range of positive-strand RNA viruses, particularly those with a genome of >10 kb in length, into a BAC vector, from which infectious RNAs can be transcribed in vitro with a bacteriophage RNA polymerase.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University
| | - Jin-Kyoung Kim
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University;
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Wang J, Liu W, Meng G, Zhao K, Gu J, Chen P, Cao R. Isolation and genome characterization of a novel duck Tembusu virus with a 74 nucleotide insertion in the 3' non-translated region. Avian Pathol 2015; 44:92-102. [PMID: 25582834 DOI: 10.1080/03079457.2015.1006167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
During investigations into the outbreak of duck Tembusu virus (DTMUV) infection in 2011 in China, a DTMUV strain (DTMUV-AH2011) was isolated from the affected ducks. The length of the genome of the DTMUV-AH2011 strain was found to be 11,064 nucleotides and to possess 10,278 nucleotides of one open reading frame (ORF), flanked by 94 nucleotides of the 5' non-translated region (NTR) and 692 nucleotides of the 3' NTR. In comparison with five fully sequenced TMUV genomes, the genome of DTMUV-AH2011 had a 74 nucleotide insertion in the 3' NTR. Comparison of the DTMUV-AH2011 fully deduced amino acid sequences with those of other Tembusu virus strains reported recently in China showed they had a highly conserved polyprotein precursor, sharing 98.9% amino acid identities, at least. The overall divergences of amino acid substitutions were randomly distributed among viral proteins except for the protein NS4B, the protein NS4B was unchanged. Knowledge of the biological characters of DTMUV and the potential role of the insertion in the 3' NTR in RNA replication will be useful for further studies of the mechanisms of virus replication and pathogenesis.
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Affiliation(s)
- Jingman Wang
- a Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine , Nanjing Agricultural University , Nanjing , China
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Du R, Wang M, Hu Z, Wang H, Deng F. An in vitro recombination-based reverse genetic system for rapid mutagenesis of structural genes of the Japanese encephalitis virus. Virol Sin 2015; 30:354-62. [PMID: 26463213 DOI: 10.1007/s12250-015-3623-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/22/2015] [Indexed: 01/12/2023] Open
Abstract
Japanese encephalitis virus (JEV) is one of the most common pathogens of severe viral encephalitis, which is a severe threat to human health. Despite instability of the JEV genome in bacteria, many strategies have been developed to establish molecular clone systems of JEV, providing convenient tools for studying the virus life cycle and virus-host interactions. In this study, we adapted an In-Fusion enzyme-based in vitro recombination method to construct a reverse genetic system of JEV, thereby providing a rapid approach to introduce mutations into the structural genes. A truncated genome without the structural genes was constructed as the backbone, and the complementary segment containing the structural genes was recombined in vitro, which was then transfected directly into virus-permissive cells. The progeny of the infectious virus was successfully detected in the supernatant of the transfected cells, and showed an identical phenotype to its parental virus. To provide a proof-of-principle, the 12 conserved cysteine residues in the envelope (E) protein of JEV were respectively mutated using this approach, and all mutations resulted in a complete failure to generate infectious virus. However, a leucine-tophenylanine mutation at amino acid 107 of the E protein did not interfere with the production of the infectious virus. These results suggested that all 12 cysteines in the E protein are essential for the JEV life cycle. In summary, a novel reverse genetic system of JEV was established for rapidly introducing mutations into structural genes, which will serve as a useful tool for functional studies.
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Affiliation(s)
- Ruikun Du
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Manli Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zhihong Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Hualin Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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Kim JK, Kim JM, Song BH, Yun SI, Yun GN, Byun SJ, Lee YM. Profiling of viral proteins expressed from the genomic RNA of Japanese encephalitis virus using a panel of 15 region-specific polyclonal rabbit antisera: implications for viral gene expression. PLoS One 2015; 10:e0124318. [PMID: 25915765 PMCID: PMC4410938 DOI: 10.1371/journal.pone.0124318] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/27/2015] [Indexed: 12/16/2022] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is closely related to West Nile (WN), yellow fever (YF), and dengue (DEN) viruses. Its plus-strand genomic RNA carries a single open reading frame encoding a polyprotein that is cleaved into three structural (C, prM/M, and E) and at least seven nonstructural (NS1/NS1', NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins, based on previous work with WNV, YFV, and DENV. Here, we aimed to profile experimentally all the viral proteins found in JEV-infected cells. We generated a collection of 15 JEV-specific polyclonal antisera covering all parts of the viral protein-coding regions, by immunizing rabbits with 14 bacterially expressed glutathione-S-transferase fusion proteins (for all nine viral proteins except NS2B) or with a chemically synthesized oligopeptide (for NS2B). In total lysates of JEV-infected BHK-21 cells, immunoblotting with these antisera revealed: (i) three mature structural proteins (~12-kDa C, ~8-kDa M, and ~53-kDa E), a precursor of M (~24-kDa prM) and three other M-related proteins (~10-14 kDa); (ii) the predicted ~45-kDa NS1 and its frameshift product, ~58-kDa NS1', with no evidence of the predicted ~25-kDa NS2A; (iii) the predicted but hardly detectable ~14-kDa NS2B and an unexpected but predominant ~12-kDa NS2B-related protein; (iv) the predicted ~69-kDa NS3 plus two major cleavage products (~34-kDa NS3N-term and ~35-kDa NS3C-term), together with at least nine minor proteins of ~16-52 kDa; (v) the predicted ~14-kDa NS4A; (vi) two NS4B-related proteins (~27-kDa NS4B and ~25-kDa NS4B'); and (vii) the predicted ~103-kDa NS5 plus at least three other NS5-related proteins (~15 kDa, ~27 kDa, and ~90 kDa). Combining these data with confocal microscopic imaging of the proteins' intracellular localization, our study is the first to provide a solid foundation for the study of JEV gene expression, which is crucial for elucidating the regulatory mechanisms of JEV genome replication and pathobiology.
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Affiliation(s)
- Jin-Kyoung Kim
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Jeong-Min Kim
- Department of Microbiology, College of Medicine, Chungbuk National University, Cheongju, South Korea
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Gil-Nam Yun
- Department of Microbiology, College of Medicine, Chungbuk National University, Cheongju, South Korea
| | - Sung-June Byun
- Animal Biotechnology Division, Korea National Institute of Animal Science, Suwon, South Korea
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
- * E-mail:
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Yun SI, Song BH, Kim JK, Yun GN, Lee EY, Li L, Kuhn RJ, Rossmann MG, Morrey JD, Lee YM. A molecularly cloned, live-attenuated japanese encephalitis vaccine SA14-14-2 virus: a conserved single amino acid in the ij Hairpin of the Viral E glycoprotein determines neurovirulence in mice. PLoS Pathog 2014; 10:e1004290. [PMID: 25077483 PMCID: PMC4117607 DOI: 10.1371/journal.ppat.1004290] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 06/18/2014] [Indexed: 01/12/2023] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus that causes fatal neurological disease in humans, is one of the most important emerging pathogens of public health significance. JEV represents the JE serogroup, which also includes West Nile, Murray Valley encephalitis, and St. Louis encephalitis viruses. Within this serogroup, JEV is a vaccine-preventable pathogen, but the molecular basis of its neurovirulence remains unknown. Here, we constructed an infectious cDNA of the most widely used live-attenuated JE vaccine, SA14-14-2, and rescued from the cDNA a molecularly cloned virus, SA14-14-2MCV, which displayed in vitro growth properties and in vivo attenuation phenotypes identical to those of its parent, SA14-14-2. To elucidate the molecular mechanism of neurovirulence, we selected three independent, highly neurovirulent variants (LD50, <1.5 PFU) from SA14-14-2MCV (LD50, >1.5×105 PFU) by serial intracerebral passage in mice. Complete genome sequence comparison revealed a total of eight point mutations, with a common single G1708→A substitution replacing a Gly with Glu at position 244 of the viral E glycoprotein. Using our infectious SA14-14-2 cDNA technology, we showed that this single Gly-to-Glu change at E-244 is sufficient to confer lethal neurovirulence in mice, including rapid development of viral spread and tissue inflammation in the central nervous system. Comprehensive site-directed mutagenesis of E-244, coupled with homology-based structure modeling, demonstrated a novel essential regulatory role in JEV neurovirulence for E-244, within the ij hairpin of the E dimerization domain. In both mouse and human neuronal cells, we further showed that the E-244 mutation altered JEV infectivity in vitro, in direct correlation with the level of neurovirulence in vivo, but had no significant impact on viral RNA replication. Our results provide a crucial step toward developing novel therapeutic and preventive strategies against JEV and possibly other encephalitic flaviviruses.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Blotting, Western
- Cloning, Molecular
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis, Japanese/genetics
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/virology
- Female
- Flow Cytometry
- Humans
- Immunoenzyme Techniques
- Japanese Encephalitis Vaccines/genetics
- Japanese Encephalitis Vaccines/immunology
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred ICR
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation/genetics
- Nervous System/virology
- Protein Conformation
- Sequence Homology, Amino Acid
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
- Virulence/genetics
- Virus Replication
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Jin-Kyoung Kim
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Gil-Nam Yun
- Department of Microbiology, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Eun-Young Lee
- Department of Anatomy, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Long Li
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Michael G. Rossmann
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - John D. Morrey
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research, College of Agriculture and Applied Sciences, Utah State University, Logan, Utah, United States of America
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Yun SI, Lee YM. Japanese encephalitis: the virus and vaccines. Hum Vaccin Immunother 2013; 10:263-79. [PMID: 24161909 PMCID: PMC4185882 DOI: 10.4161/hv.26902] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/14/2013] [Accepted: 10/22/2013] [Indexed: 12/11/2022] Open
Abstract
Japanese encephalitis (JE) is an infectious disease of the central nervous system caused by Japanese encephalitis virus (JEV), a zoonotic mosquito-borne flavivirus. JEV is prevalent in much of Asia and the Western Pacific, with over 4 billion people living at risk of infection. In the absence of antiviral intervention, vaccination is the only strategy to develop long-term sustainable protection against JEV infection. Over the past half-century, a mouse brain-derived inactivated vaccine has been used internationally for active immunization. To date, however, JEV is still a clinically important, emerging, and re-emerging human pathogen of global significance. In recent years, production of the mouse brain-derived vaccine has been discontinued, but 3 new cell culture-derived vaccines are available in various parts of the world. Here we review current aspects of JEV biology, summarize the 4 types of JEV vaccine, and discuss the potential of an infectious JEV cDNA technology for future vaccine development.
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Affiliation(s)
- Sang-Im Yun
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research; College of Agriculture and Applied Sciences; Utah State University; Logan, UT USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences; Utah Science Technology and Research; College of Agriculture and Applied Sciences; Utah State University; Logan, UT USA
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Genetic analysis of West Nile virus isolates from an outbreak in Idaho, United States, 2006-2007. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:4486-506. [PMID: 24065039 PMCID: PMC3799518 DOI: 10.3390/ijerph10094486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/12/2013] [Accepted: 09/16/2013] [Indexed: 12/26/2022]
Abstract
West Nile virus (WNV) appeared in the U.S. in 1999 and has since become endemic, with yearly summer epidemics causing tens of thousands of cases of serious disease over the past 14 years. Analysis of WNV strains isolated during the 2006–2007 epidemic seasons demonstrates that a new genetic variant had emerged coincidentally with an intense outbreak in Idaho during 2006. The isolates belonging to the new variant carry a 13 nt deletion, termed ID-Δ13, located at the variable region of the 3′UTR, and are genetically related. The analysis of deletions and insertions in the 3′UTR of two major lineages of WNV revealed the presence of conserved repeats and two indel motifs in the variable region of the 3′UTR. One human and two bird isolates from the Idaho 2006–2007 outbreaks were sequenced using Illumina technology and within-host variability was analyzed. Continued monitoring of new genetic variants is important for public health as WNV continues to evolve.
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Nonsuppurative encephalomyelitis in a calf in Japan and isolation of Japanese encephalitis virus genotype 1 from the affected calf. J Clin Microbiol 2013; 51:3448-53. [PMID: 23885004 DOI: 10.1128/jcm.00737-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Japanese encephalitis virus (JEV) was isolated from the cerebrum of a calf which showed severe neurological symptoms in late September 2009, and the JEV isolate was revealed to be of genotype 1. This is the first report describing the isolation of genotype 1 JEV from cattle.
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Japanese encephalitis virus non-coding RNA inhibits activation of interferon by blocking nuclear translocation of interferon regulatory factor 3. Vet Microbiol 2013; 166:11-21. [PMID: 23755934 DOI: 10.1016/j.vetmic.2013.04.026] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 04/26/2013] [Accepted: 04/30/2013] [Indexed: 12/24/2022]
Abstract
Noncoding RNA (ncRNA) plays a critical role in modulating a broad range of diseases. All arthropod-borne flaviviruses produce short fragment ncRNA (sfRNA) collinear with highly conserved regions of the 3'-untranslated region (UTR) in the viral genome. We show that the molar ratio of sfRNA to genomic RNA in Japanese encephalitis virus (JEV) persistently infected cells is greater than that in acutely infected cells, indicating an sfRNA role in establishing persistent infection. Transfecting excess quantities of sfRNA into JEV-infected cells reduced interferon-β (IFN-β) promoter activity by 57% and IFN-β mRNA levels by 52%, compared to mock-transfected cells. Transfection of sfRNA into JEV-infected cells also reduced phosphorylation of interferon regulatory factor-3 (IRF-3), the IFN-β upstream regulator, and blocked roughly 30% of IRF-3 nuclear localization. Furthermore, JEV-infected sfRNA transfected cells produced 23% less IFN-β-stimulated apoptosis than mock-transfected groups did. Taken together, these results suggest that sfRNA plays a role against host-cell antiviral responses, prevents cells from undergoing apoptosis, and thus contributes to viral persistence.
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Yang CC, Tsai MH, Hu HS, Pu SY, Wu RH, Wu SH, Lin HM, Song JS, Chao YS, Yueh A. Characterization of an efficient dengue virus replicon for development of assays of discovery of small molecules against dengue virus. Antiviral Res 2013; 98:228-41. [PMID: 23499649 DOI: 10.1016/j.antiviral.2013.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 02/19/2013] [Accepted: 03/01/2013] [Indexed: 01/04/2023]
Abstract
Dengue virus (DENV) is a public health threat to approximately 40% of the global population. At present, neither licensed vaccines nor effective therapies exist, and the mechanism of viral RNA replication is not well understood. Here, we report the development of efficient Renilla luciferase reporter-based DENV replicons that contain the full-length capsid sequence for transient and stable DENV RNA replication. A comparison of the transient and stable expression of this RNA-launched replicon to replicons containing various deletions revealed dengue replicon containing entire mature capsid RNA element has higher replicon activity. An efficient DNA-launched DENV replicon, pCMV-DV2Rep, containing a full-length capsid sequence, was created and successfully applied to evaluate the potency of known DENV inhibitors. Stable cell lines harboring the DENV replicon were easily established by transfecting pCMV-DV2Rep into BHK21 cells. Steady and high replicon reporter signals were observed in the stable DENV replicon cells, even after 30 passages. The stable DENV replicon cells were successfully used to determine the potency of known DENV inhibitors. A high-throughput screening assay based on stable DENV replicon cells was evaluated and shown to have an excellent Z' factor of 0.74. Altogether, the development of our efficient DENV replicon system will facilitate the study of virus replication and the discovery of antiviral compounds.
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Affiliation(s)
- Chi-Chen Yang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 350, Taiwan, ROC
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Li SH, Li XF, Zhao H, Deng YQ, Yu XD, Zhu SY, Jiang T, Ye Q, Qin ED, Qin CF. Development and characterization of the replicon system of Japanese encephalitis live vaccine virus SA14-14-2. Virol J 2013; 10:64. [PMID: 23442449 PMCID: PMC3608946 DOI: 10.1186/1743-422x-10-64] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/22/2013] [Indexed: 11/17/2022] Open
Abstract
Background Viral self-replicating sub-genomic replicons represent a powerful tool for studying viral genome replication, antiviral screening and chimeric vaccine development. Many kinds of flavivirus replicons have been developed with broad applications. Findings The replicon system of JEV live vaccine strain SA14-14-2 was successfully developed in this study. Two kinds of replicons that express enhanced green fluorescent protein (EGFP) and Renilla luciferase (R.luc) were constructed under the control of SP6 promoter, respectively. Robust EGFP and R.luc signals could be detected in the replicon-transfected BHK-21 cells. Furthermore, the potential effects of selected amino acids in the C-terminal of envelope protein on replication were characterized using the replicon system. Conclusions Our results provide a useful platform not only for the study of JEV replication, but also for antiviral screening and chimeric vaccine development.
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Affiliation(s)
- Shi-Hua Li
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
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Kato F, Kotaki A, Yamaguchi Y, Shiba H, Hosono K, Harada S, Saijo M, Kurane I, Takasaki T, Tajima S. Identification and characterization of the short variable region of the Japanese encephalitis virus 3' NTR. Virus Genes 2011; 44:191-7. [PMID: 22057659 DOI: 10.1007/s11262-011-0685-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Accepted: 10/24/2011] [Indexed: 11/25/2022]
Abstract
Since the 1980s, the Japanese encephalitis virus (JEV) variants with slightly short variable regions (VR) of the 3' non-translated region (NTR) have been found; however, the implications of these short VR remain unclear. We recently identified two novel types of short VR (5 and 9 nt shorter than that of major group of genotype I JEV strains) of genotype I JEV isolates. To elucidate the impact of these short VR on the replication and virulence of JEV, we generated five recombinant JEV viruses: M41-d5 and M41-d9 have deletions in the VR that correspond to those observed in some recent JEV isolates, M41-d5d9 has both the 5- and 9-nt deletions in the VR, M41-d27 has a large deletion that encompasses both the 5- and 9-nt deletion regions, and M41-a13 has a 13-nt sequence insertion of the genotype III JEV strain Beijing-1 into the parent genotype I JEV strain Mie/41/2002 genome. The recombinant viruses and the parent virus, except for the M41-d27 mutant, showed similar growth properties in mammalian and mosquito cell lines. Mouse challenge experiments indicated that no significant differences among the recombinant viruses M41-d5d9, M41-d27, M41-a13, and the parent virus. Our results suggest that the short VR in JEV 3' NTR do not affect its growth in vitro or its pathogenicity in mice.
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Affiliation(s)
- Fumihiro Kato
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
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Fan YH, Nadar M, Chen CC, Weng CC, Lin YT, Chang RY. Small noncoding RNA modulates Japanese encephalitis virus replication and translation in trans. Virol J 2011; 8:492. [PMID: 22040380 PMCID: PMC3221644 DOI: 10.1186/1743-422x-8-492] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 11/01/2011] [Indexed: 12/14/2022] Open
Abstract
Background Sequence and structural elements in the 3'-untranslated region (UTR) of Japanese encephalitis virus (JEV) are known to regulate translation and replication. We previously reported an abundant accumulation of small subgenomic flaviviral RNA (sfRNA) which is collinear with the highly conserved regions of the 3'-UTR in JEV-infected cells. However, function of the sfRNA in JEV life cycle remains unknown. Results Northern blot and real-time RT-PCR analyses indicated that the sfRNA becomes apparent at the time point at which minus-strand RNA (antigenome) reaches a plateau suggesting a role for sfRNA in the regulation of antigenome synthesis. Transfection of minus-sense sfRNA into JEV-infected cells, in order to counter the effects of plus-sense sfRNA, resulted in higher levels of antigenome suggesting that the presence of the sfRNA inhibits antigenome synthesis. Trans-acting effect of sfRNA on JEV translation was studied using a reporter mRNA containing the luciferase gene fused to partial coding regions of JEV and flanked by the respective JEV UTRs. In vivo and in vitro translation revealed that sfRNA inhibited JEV translation. Conclusions Our results indicate that sfRNA modulates viral translation and replication in trans.
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Affiliation(s)
- Yi-Hsin Fan
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan
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Lim YS, Tran HTL, Park SJ, Yim SA, Hwang SB. Peptidyl-prolyl isomerase Pin1 is a cellular factor required for hepatitis C virus propagation. J Virol 2011; 85:8777-88. [PMID: 21680504 PMCID: PMC3165832 DOI: 10.1128/jvi.02533-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Accepted: 05/27/2011] [Indexed: 12/17/2022] Open
Abstract
The life cycle of hepatitis C virus (HCV) is highly dependent on cellular factors. Using small interfering RNA (siRNA) library screening, we identified peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) as a host factor involved in HCV propagation. Here we demonstrated that silencing of Pin1 expression resulted in decreases in HCV replication in both HCV replicon cells and cell culture-grown HCV (HCVcc)-infected cells, whereas overexpression of Pin1 increased HCV replication. Pin1 interacted with both the NS5A and NS5B proteins. However, Pin1 expression was increased only by the NS5B protein. Both the protein binding and isomerase activities of Pin1 were required for HCV replication. Juglone, a natural inhibitor of Pin1, inhibited HCV propagation by inhibiting the interplay between the Pin1 and HCV NS5A/NS5B proteins. These data indicate that Pin1 modulates HCV propagation and may contribute to HCV-induced liver pathogenesis.
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Affiliation(s)
- Yun-Sook Lim
- National Research Laboratory of Hepatitis C Virus, Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang 431-060, South Korea
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Unni SK, Růžek D, Chhatbar C, Mishra R, Johri MK, Singh SK. Japanese encephalitis virus: from genome to infectome. Microbes Infect 2011; 13:312-21. [DOI: 10.1016/j.micinf.2011.01.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 12/30/2010] [Accepted: 01/03/2011] [Indexed: 11/24/2022]
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Wu R, Tian Y, Deng J, Yang K, Liang W, Guo R, Duan Z, Liu Z, Zhou D, Xu D. Multiple amino acid variations in the nonstructural proteins of swine Japanese encephalitis virus alter its virulence in mice. Arch Virol 2010; 156:685-8. [DOI: 10.1007/s00705-010-0871-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 11/18/2010] [Indexed: 11/24/2022]
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The 5' and 3' downstream AUG region elements are required for mosquito-borne flavivirus RNA replication. J Virol 2010; 85:1900-5. [PMID: 21123391 DOI: 10.1128/jvi.02037-10] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Flaviviruses require complementarity between the 5' and 3' ends of the genome for RNA replication. For mosquito-borne flaviviruses, the cyclization sequences (CS) and upstream of AUG region (UAR) elements at the genomic termini are necessary for viral RNA replication, and a third motif, the downstream of AUG region (DAR), was recently designated for dengue virus. The 3' DAR sequence is also part of a hairpin (HP-3'SL), and both complementarity between 5' and 3' DAR motifs and formation of the HP-3'SL in the absence of the 5' end are conserved among mosquito-borne flaviviruses. Using West Nile virus as a model, we demonstrate that 5'-3' DAR complementarity and HP-3'SL formation are essential for viral RNA replication.
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Abstract
Flaviviruses are a group of single-stranded, positive-sense RNA viruses causing ∼100 million infections per year. We have recently shown that flaviviruses produce a unique, small, noncoding RNA (∼0.5 kb) derived from the 3' untranslated region (UTR) of the genomic RNA (gRNA), which is required for flavivirus-induced cytopathicity and pathogenicity (G. P. Pijlman et al., Cell Host Microbe, 4: 579-591, 2008). This RNA (subgenomic flavivirus RNA [sfRNA]) is a product of incomplete degradation of gRNA presumably by the cellular 5'-3' exoribonuclease XRN1, which stalls on the rigid secondary structure stem-loop II (SL-II) located at the beginning of the 3' UTR. Mutations or deletions of various secondary structures in the 3' UTR resulted in the loss of full-length sfRNA (sfRNA1) and production of smaller and less abundant sfRNAs (sfRNA2 and sfRNA3). Here, we investigated in detail the importance of West Nile virus Kunjin (WNV(KUN)) 3' UTR secondary structures as well as tertiary interactions for sfRNA formation. We show that secondary structures SL-IV and dumbbell 1 (DB1) downstream of SL-II are able to prevent further degradation of gRNA when the SL-II structure is deleted, leading to production of sfRNA2 and sfRNA3, respectively. We also show that a number of pseudoknot (PK) interactions, in particular PK1 stabilizing SL-II and PK3 stabilizing DB1, are required for protection of gRNA from nuclease degradation and production of sfRNA. Our results show that PK interactions play a vital role in the production of nuclease-resistant sfRNA, which is essential for viral cytopathicity in cells and pathogenicity in mice.
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Schlick P, Kofler RM, Schittl B, Taucher C, Nagy E, Meinke A, Mandl CW. Characterization of West Nile virus live vaccine candidates attenuated by capsid deletion mutations. Vaccine 2010; 28:5903-9. [PMID: 20600500 DOI: 10.1016/j.vaccine.2010.06.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 06/10/2010] [Indexed: 12/16/2022]
Abstract
Protein C deletion mutants of West Nile virus (WNV) were evaluated for their potential use as live virus vaccine candidates in vivo. Double and triple mutants carrying small deletions and second-site point mutations, as well as mutants with large deletions of 36 and 37 amino acid residues were tested in a stringent mouse challenge model. The mutant viruses were found to be non-pathogenic and to induce protective immunity in a wide range of inoculation doses (10(1)-10(6)FFU). Furthermore, the effects of combining three different previously identified resuscitating point mutations, as well as the combination of a large protein C deletion with a deletion mutation in the 3' non-coding region were studied. The data indicate that the production of safe and efficacious WNV live vaccines based on protein C deletion mutations is feasible.
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Affiliation(s)
- Petra Schlick
- Intercell AG, Campus Vienna Biocenter 3, Vienna, Austria.
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