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Yi W, Wang H, Qin H, Wang Q, Guo R, Wen G, Pan Z. Construction and efficacy of a new live chimeric C-strain vaccine with DIVA characteristics against classical swine fever. Vaccine 2023; 41:2003-2012. [PMID: 36803898 DOI: 10.1016/j.vaccine.2023.02.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/21/2023]
Abstract
To develop the new classical swine fever (CSF) vaccine candidate with differentiating infected vaccinated animals (DIVA) characteristics, a chimeric CSF virus (CSFV) was constructed based on an infectious cDNA clone of the CSF vaccine C-strain. The 5'- and 3'-untranslated regions (UTRs) and partial E2 region (residues 690-860) of the C-strain were substituted with the corresponding regions of bovine viral diarrhoea virus (BVDV) to construct the chimeric cDNA clone pC/bUTRs-tE2. The chimeric virus rC/bUTRs-tE2 was generated by several passages of pC/bUTRs-tE2-transfected PK15 cells. Stable growth and genetic properties of rC/bUTRs-tE2 were obtained after 30 serial passages. Compared to parental rC/bUTRs-tE2 (1st passage), two residue mutations (M834K and M979K) located in E2 in rC/bUTRs-tE2 P30 were observed. Compared to the C-strain, rC/bUTRs-tE2 exhibited unchanged cell tropism and decreased plaque-forming ability. Substituting the C-strain UTRs with the BVDV UTRs resulted in significantly increased viral replication in PK15 cells. Compared to CSFV Erns-positive and BVDV tE2-negative antibody responses induced by the CSF vaccine C-strain, immunization of rabbits and piglets with rC/bUTRs-tE2 resulted in serological profiles of CSFV Erns- and BVDV tE2-positive antibodies, which are used to serologically discriminate pigs that are clinically infected and vaccinated. Vaccination of piglets with rC/bUTRs-tE2 conferred complete protection against lethal CSFV challenge. Our results suggest that rC/bUTRs-tE2 is a promising new CSF marker vaccine candidate.
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Affiliation(s)
- Weicheng Yi
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Hao Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Huan Qin
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Laboratory, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430015, China
| | - Qin Wang
- World Organisation for Animal Health Reference Laboratory for Classical Swine Fever, China Institute of Veterinary Drug Control, Beijing 100081, China
| | - Rui Guo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Guoyuan Wen
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Zishu Pan
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
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Proline to Threonine Mutation at Position 162 of NS5B of Classical Swine Fever Virus Vaccine C Strain Promoted Genome Replication and Infectious Virus Production by Facilitating Initiation of RNA Synthesis. Viruses 2021; 13:v13081523. [PMID: 34452387 PMCID: PMC8402891 DOI: 10.3390/v13081523] [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: 05/11/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
The 3′untranslated region (3′UTR) and NS5B of classical swine fever virus (CSFV) play vital roles in viral genome replication. In this study, two chimeric viruses, vC/SM3′UTR and vC/b3′UTR, with 3′UTR substitution of CSFV Shimen strain or bovine viral diarrhea virus (BVDV) NADL strain, were constructed based on the infectious cDNA clone of CSFV vaccine C strain, respectively. After virus rescue, each recombinant chimeric virus was subjected to continuous passages in PK-15 cells. The representative passaged viruses were characterized and sequenced. Serial passages resulted in generation of mutations and the passaged viruses exhibited significantly increased genomic replication efficiency and infectious virus production compared to parent viruses. A proline to threonine mutation at position 162 of NS5B was identified in both passaged vC/SM3′UTR and vC/b3′UTR. We generated P162T mutants of two chimeras using the reverse genetics system, separately. The single P162T mutation in NS5B of vC/SM3′UTR or vC/b3′UTR played a key role in increased viral genome replication and infectious virus production. The P162T mutation increased vC/SM3′UTRP162T replication in rabbits. From RNA-dependent RNA polymerase (RdRp) assays in vitro, the NS5B containing P162T mutation (NS5BP162T) exhibited enhanced RdRp activity for different RNA templates. We further identified that the enhanced RdRp activity originated from increased initiation efficiency of RNA synthesis. These findings revealed a novel function for the NS5B residue 162 in modulating pestivirus replication.
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Synergistic roles of the E2 glycoprotein and 3′ untranslated region in the increased genomic stability of chimeric classical swine fever virus with attenuated phenotypes. Arch Virol 2017; 162:2667-2678. [DOI: 10.1007/s00705-017-3427-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 05/17/2017] [Indexed: 10/19/2022]
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Coronado L, Liniger M, Muñoz-González S, Postel A, Pérez LJ, Pérez-Simó M, Perera CL, Frías-Lepoureau MT, Rosell R, Grundhoff A, Indenbirken D, Alawi M, Fischer N, Becher P, Ruggli N, Ganges L. Novel poly-uridine insertion in the 3'UTR and E2 amino acid substitutions in a low virulent classical swine fever virus. Vet Microbiol 2017; 201:103-112. [PMID: 28284595 DOI: 10.1016/j.vetmic.2017.01.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 12/24/2022]
Abstract
In this study, we compared the virulence in weaner pigs of the Pinar del Rio isolate and the virulent Margarita strain. The latter caused the Cuban classical swine fever (CSF) outbreak of 1993. Our results showed that the Pinar del Rio virus isolated during an endemic phase is clearly of low virulence. We analysed the complete nucleotide sequence of the Pinar del Rio virus isolated after persistence in newborn piglets, as well as the genome sequence of the inoculum. The consensus genome sequence of the Pinar del Rio virus remained completely unchanged after 28days of persistent infection in swine. More importantly, a unique poly-uridine tract was discovered in the 3'UTR of the Pinar del Rio virus, which was not found in the Margarita virus or any other known CSFV sequences. Based on RNA secondary structure prediction, the poly-uridine tract results in a long single-stranded intervening sequence (SS) between the stem-loops I and II of the 3'UTR, without major changes in the stem- loop structures when compared to the Margarita virus. The possible implications of this novel insertion on persistence and attenuation remain to be investigated. In addition, comparison of the amino acid sequence of the viral proteins Erns, E1, E2 and p7 of the Margarita and Pinar del Rio viruses showed that all non-conservative amino acid substitutions acquired by the Pinar del Rio isolate clustered in E2, with two of them being located within the B/C domain. Immunisation and cross-neutralisation experiments in pigs and rabbits suggest differences between these two viruses, which may be attributable to the amino acid differences observed in E2. Altogether, these data provide fresh insights into viral molecular features which might be associated with the attenuation and adaptation of CSFV for persistence in the field.
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Affiliation(s)
- Liani Coronado
- Centro Nacional de Sanidad Agropecuaria (CENSA), La Habana, Cuba; IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Matthias Liniger
- Institute of Virology and Immunology IVI, Mittelhäusern, Switzerland
| | - Sara Muñoz-González
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Alexander Postel
- EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, Department of Infectious Diseases, University of Veterinary Medicine, Hannover, Germany
| | | | - Marta Pérez-Simó
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | | | | | - Rosa Rosell
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain; Departamentd'Agricultura, Ramaderia, Pesca, Alimentació i Medi Natural, (DAAM), Generalitat de Catalunya, Spain
| | - Adam Grundhoff
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Research Group Virus Genomics, Hamburg, Germany
| | - Daniela Indenbirken
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Research Group Virus Genomics, Hamburg, Germany
| | - Malik Alawi
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Research Group Virus Genomics, Hamburg, Germany; Bioinformatics Service Facility, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicole Fischer
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paul Becher
- EU and OIE Reference Laboratory for Classical Swine Fever, Institute of Virology, Department of Infectious Diseases, University of Veterinary Medicine, Hannover, Germany
| | - Nicolas Ruggli
- Institute of Virology and Immunology IVI, Mittelhäusern, Switzerland
| | - Llilianne Ganges
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
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Li Y, Wang X, Sun Y, Li LF, Zhang L, Li S, Luo Y, Qiu HJ. Generation and evaluation of a chimeric classical swine fever virus expressing a visible marker gene. Arch Virol 2015; 161:563-71. [PMID: 26614259 DOI: 10.1007/s00705-015-2693-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 11/16/2015] [Indexed: 11/24/2022]
Abstract
Classical swine fever virus (CSFV) is a noncytopathogenic virus, and the incorporation of an enhanced green fluorescent protein (EGFP) tag into the viral genome provides a means of direct monitoring of viral infection without immunostaining. It is well established that the 3' untranslated region (3'-UTR) of the CSFV plays an important role in viral RNA replication. Although CSFV carrying a reporter gene and chimeric CSFV have been generated and evaluated, a chimeric CSFV with a visible marker has not yet been reported. Here, we generated and evaluated a chimeric virus containing the EGFP tag and the 3'-UTR from vaccine strain HCLV (C-strain) in the genetic background of the highly virulent CSFV Shimen strain. The chimeric marker CSFV was fluorescent and had an approximately 100-fold lower viral titer, lower replication level of viral genome, and weaker fluorescence intensity than the recombinant CSFV with only the EGFP tag or the parental virus. Furthermore, the marker chimera was avirulent and displayed no viremia in inoculated pigs, which were completely protected from lethal CSFV challenge as early as 15 days post-inoculation. The chimeric marker virus was visible in vitro and attenuated in vitro and in vivo, which suggests that CSFV can be engineered to produce attenuated variants with a visible marker to facilitate in vitro studies of CSFV infection and replication and to develop of novel vaccines against CSF.
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Affiliation(s)
- Yongfeng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Xiao Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Lian-Feng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Lingkai Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin, 150001, Heilongjiang, China.
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Li C, Li Y, Shen L, Huang J, Sun Y, Luo Y, Zhao B, Wang C, Yuan J, Qiu HJ. The role of noncoding regions of classical swine fever virus C-strain in its adaptation to the rabbit. Virus Res 2014; 183:117-22. [DOI: 10.1016/j.virusres.2014.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/06/2014] [Accepted: 02/07/2014] [Indexed: 11/16/2022]
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The 3'-terminal hexamer sequence of classical swine fever virus RNA plays a role in negatively regulating the IRES-mediated translation. PLoS One 2012; 7:e33764. [PMID: 22432046 PMCID: PMC3303849 DOI: 10.1371/journal.pone.0033764] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 02/17/2012] [Indexed: 12/14/2022] Open
Abstract
The 3′ untranslated region (UTR) is usually involved in the switch of the translation and replication for a positive-sense RNA virus. To understand the 3′ UTR involved in an internal ribosome entry site (IRES)-mediated translation in Classical swine fever virus (CSFV), we first confirmed the predicted secondary structure (designated as SLI, SLII, SLIII, and SLIV) by enzymatic probing. Using a reporter assay in which the luciferase expression is under the control of CSFV 5′ and 3′ UTRs, we found that the 3′ UTR harbors the positive and negative regulatory elements for translational control. Unlike other stem loops, SLI acts as a repressor for expression of the reporter gene. The negative cis-acting element in SLI is further mapped to the very 3′-end hexamer CGGCCC sequence. Further, the CSFV IRES-mediated translation can be enhanced by the heterologous 3′-ends such as the poly(A) or the 3′ UTR of Hepatitis C virus (HCV). Interestingly, such an enhancement was repressed by flanking this hexamer to the end of poly(A) or HCV 3′ UTR. After sequence comparison and alignment, we have found that this hexamer sequence could hypothetically base pair with the sequence in the IRES IIId1, the 40 S ribosomal subunit binding site for the translational initiation, located at the 5′ UTR. In conclusion, we have found that the 3′-end terminal sequence can play a role in regulating the translation of CSFV.
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Lack of phylogenetic evidence that the Shimen strain is the parental strain of the lapinized Chinese strain (C-strain) vaccine against classical swine fever. Arch Virol 2011; 156:1041-4. [DOI: 10.1007/s00705-011-0948-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 02/04/2011] [Indexed: 11/26/2022]
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Xiao M, Wang Y, Zhu Z, Ding C, Yu J, Wan L, Chen J. Influence of the 5'-proximal elements of the 5'-untranslated region of classical swine fever virus on translation and replication. J Gen Virol 2011; 92:1087-1096. [PMID: 21307229 DOI: 10.1099/vir.0.027870-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The 5'-terminal sequence spanning nt 1-29 of the 5'-untranslated region of classical swine fever virus (CSFV) forms a 5'-proximal stem-loop structure known as domain Ia. Deletions and replacement mutations were performed to examine the role of this domain. Deletion of the 5'-proximal nucleotides and disruption of the stem-loop structure greatly increased internal ribosome entry site-mediated translation but abolished the replication of the replicons. Internal deletions resulting in a change in the size of the loop of domain Ia, and even removal of the entire domain, did not substantially change the translation activity, but reduced the replication of CSFV replicons provided the replicons contained the extreme 5'-GUAU terminal sequence. Internal replacements leading to a change in the nucleotide sequence of the loop did not alter the translation and replication activities of the CSFV RNA replicon, and did not influence the rescue of viruses and growth characteristics of new viruses. These results may be important for our understanding of the regulation of translation, replication and encapsidation in CSFV and other positive-sense RNA viruses.
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Affiliation(s)
- Ming Xiao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Yujing Wang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Zailing Zhu
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Chengli Ding
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Jialin Yu
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Lingzhu Wan
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
| | - Jun Chen
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, PR China
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Sheng C, Zhu Z, Yu J, Wan L, Wang Y, Chen J, Gu F, Xiao M. Characterization of NS3, NS5A and NS5B of classical swine fever virus through mutation and complementation analysis. Vet Microbiol 2010; 140:72-80. [DOI: 10.1016/j.vetmic.2009.07.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Revised: 07/04/2009] [Accepted: 07/31/2009] [Indexed: 11/16/2022]
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Complete genome sequence of attenuated low-temperature Thiverval strain of classical swine fever virus. Virus Genes 2008; 36:531-8. [DOI: 10.1007/s11262-008-0229-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Accepted: 03/31/2008] [Indexed: 12/29/2022]
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12
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12-nt insertion in 3′ untranslated region leads to attenuation of classic swine fever virus and protects host against lethal challenge. Virology 2008; 374:390-8. [DOI: 10.1016/j.virol.2008.01.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 12/05/2007] [Accepted: 01/05/2008] [Indexed: 11/23/2022]
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Johnson N, Freuling C, Marston DA, Tordo N, Fooks AR, Müller T. Identification of European bat lyssavirus isolates with short genomic insertions. Virus Res 2007; 128:140-3. [PMID: 17521764 DOI: 10.1016/j.virusres.2007.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 04/05/2007] [Accepted: 04/06/2007] [Indexed: 11/22/2022]
Abstract
Molecular typing has consistently identified European bat lyssaviruses from Germany as EBLV type 1a (EBLV-1a). This report confirms the presence of the closely related EBLV-1b in southern Germany, a group previously reported from The Netherlands, France and Spain. Furthermore, two of three German EBLV-1b isolates contain a 6 base pair insertion within the 3' untranslated region (UTR) of the nucleoprotein gene. This feature was shared with a third EBLV-1b isolate from a region of France adjacent to the French-German border. Further investigation revealed a two base pair insertion in a single isolate of EBLV-2 at the same genomic location. Although the length of the nucleoprotein gene 3'UTRs do vary between lyssavirus genotypes, such insertions have not been recorded within genotypes and could be the result of duplications within the nucleoprotein mRNA transcript polyadenylation signal.
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Affiliation(s)
- Nicholas Johnson
- Rabies and Wildlife Zoonoses Group, WHO Collaborating Centre for the Characterization of Rabies and Rabies-Related Viruses, Veterinary Laboratories Agency, Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK.
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Sheng C, Xiao M, Geng X, Liu J, Wang Y, Gu F. Characterization of interaction of classical swine fever virus NS3 helicase with 3' untranslated region. Virus Res 2007; 129:43-53. [PMID: 17566586 DOI: 10.1016/j.virusres.2007.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2007] [Revised: 05/03/2007] [Accepted: 05/04/2007] [Indexed: 11/24/2022]
Abstract
The classical swine fever virus (CSFV) full-length NS3 protein (NS3F) and the truncated NS3 protein (NS3H) with postulated helicase domain were expressed and demonstrated to have helicase activity. Further, the electrophoretic mobility shift assays containing NS3H and the viral 3' terminal sequences showed that NS3H specifically bound to the plus- and minus-strand 3'UTR. The minus-strand 3'UTR had higher binding activity. The 21-nt fragments at the 3'-most terminal sequences of both 3'UTRs were essential to NS3H binding. A 12-nt insertion, CUUUUUUCUUUU, present in the 3'UTR of a CSFV live attenuated vaccine strain, was also found to be deleterious to helicase binding. Intact secondary structure of 3' terminal sequence of 3'UTR might be important in helicase binding. Our results show that interaction between the helicase and the viral 3'UTR is similar to that between the replicase and the 3'UTR, suggesting that NS3 helicase is important for CSFV genomic replication.
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Affiliation(s)
- Chun Sheng
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China
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QIU HJ, SHEN RX, TONG GZ. The Lapinized Chinese Strain Vaccine Against Classical Swine Fever Virus: A Retrospective Review Spanning Half A Century. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1671-2927(06)60013-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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