1
|
Li Y, Zhang L, Wang L, Li J, Zhao Y, Liu F, Wang Q. Structure and function of type IV IRES in picornaviruses: a systematic review. Front Microbiol 2024; 15:1415698. [PMID: 38855772 PMCID: PMC11157119 DOI: 10.3389/fmicb.2024.1415698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/13/2024] [Indexed: 06/11/2024] Open
Abstract
The Picornaviridae is a family of icosahedral viruses with single-stranded, highly diverse positive-sense RNA genomes. Virions consist of a capsid, without envelope, surrounding a core of RNA genome. A typical genome of picornavirus harbors a well-conserved and highly structured RNA element known as the internal ribosome entry site (IRES), functionally essential for viral replication and protein translation. Based on differences in their structures and mechanisms of action, picornaviral IRESs have been categorized into five types: type I, II, III, IV, and V. Compared with the type IV IRES, the others not only are structurally complicated, but also involve multiple initiation factors for triggering protein translation. The type IV IRES, often referred to as hepatitis C virus (HCV)-like IRES due to its structural resemblance to the HCV IRES, exhibits a simpler and more compact structure than those of the other four. The increasing identification of picornaviruses with the type IV IRES suggests that this IRES type seems to reveal strong retention and adaptation in terms of viral evolution. Here, we systematically reviewed structural features and biological functions of the type IV IRES in picornaviruses. A comprehensive understanding of the roles of type IV IRESs will contribute to elucidating the replication mechanism and pathogenesis of picornaviruses.
Collapse
Affiliation(s)
- Yan Li
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, China
- Qingdao Center for Animal Disease Control and Prevention, Qingdao, China
| | - Lei Zhang
- Shandong New Hope Liuhe Group Co., Ltd., Qingdao, China
| | - Ling Wang
- University Hospital, Qingdao Agricultural University, Qingdao, China
| | - Jing Li
- Market Supervision Administration of Huangdao District, Qingdao, China
| | - Yanwei Zhao
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, China
| | - Fuxiao Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, China
| | - Qianqian Wang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, China
| |
Collapse
|
2
|
Okamoto R, Ito N, Ide Y, Kitab B, Sakoda Y, Tsukiyama-Kohara K. Development of short hairpin RNA expression vectors targeting the internal ribosomal entry site of the classical swine fever virus genomic RNA. BMC Biotechnol 2023; 23:37. [PMID: 37684601 PMCID: PMC10492304 DOI: 10.1186/s12896-023-00805-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Classical swine fever (CSF) is a fatal contagious disease affecting pigs caused by classical swine fever virus (CSFV). The disease can be transmitted by pigs and wild boars, and it is difficult to prevent and control. To obtain necessary information to establish the CSFV resistant animals in a future study, we designed lentiviral vector-delivered short hairpin RNAs (shRNAs) targeting the conserved domain III of the internal ribosomal entry site (IRES) of the CSFV genomic RNA. RESULTS First, we confirmed the effects of siRNAs on CSFV-IRES activity. We observed significant inhibition of CSFV-IRES activity by si42 (domain IIIa), si107 (domain IIIc), and si198 (domain IIIf) in SK-L cells and si56 (domain IIIb), si142 (domain IIId1) and si198 in HEK293 cells without affecting the amount of luciferase RNA. Next, we constructed lentiviral vectors expressing shRNA based on siRNA sequences. Treatment with shRNA-expressing lentivirus was examined at 7 and 14 days post infection in SK-L cells and HEK293 cells, and CSFV-IRES was significantly suppressed at 14 days (sh42) post infection in HEK293 cells without significant cytotoxicity. Next, we examined the silencing effect of siRNA on CSFV replicon RNA and observed a significant effect by si198 after 2 days of treatment and by shRNA-expressing lentivirus (sh56, sh142, and sh198) infection after 14 days of treatment. Treatment of sh198-expressing lentivirus significantly suppressed CSFV infection at 3 days after infection. CONCLUSION The IRES targeting sh198 expressing lentivirus vector can be a candidate tool for CSFV infection control.
Collapse
Affiliation(s)
- Riai Okamoto
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Nobumasa Ito
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Yutaro Ide
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Bouchra Kitab
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Yoshihiro Sakoda
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, 060-0818, Japan
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan.
- Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan.
| |
Collapse
|
3
|
Ide Y, Kitab B, Ito N, Okamoto R, Tamura Y, Matsui T, Sakoda Y, Tsukiyama-Kohara K. Characterization of host factors associated with the internal ribosomal entry sites of foot-and-mouth disease and classical swine fever viruses. Sci Rep 2022; 12:6709. [PMID: 35468926 PMCID: PMC9039067 DOI: 10.1038/s41598-022-10437-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 04/01/2022] [Indexed: 11/18/2022] Open
Abstract
Foot-and-mouth disease virus (FMDV) and classical swine fever virus (CSFV) possess positive-sense single-stranded RNA genomes and an internal ribosomal entry site (IRES) element within their 5′-untranslated regions. To investigate the common host factors associated with these IRESs, we established cell lines expressing a bicistronic luciferase reporter plasmid containing an FMDV-IRES or CSFV-IRES element between the Renilla and firefly luciferase genes. First, we treated FMDV-IRES cells with the French maritime pine extract, Pycnogenol (PYC), and examined its suppressive effect on FMDV-IRES activity, as PYC has been reported to have antiviral properties. Next, we performed microarray analysis to identify the host factors that modified their expression upon treatment with PYC, and confirmed their function using specific siRNAs. We found that polycystic kidney disease 1-like 3 (PKD1L3) and ubiquitin-specific peptidase 31 (USP31) were associated with FMDV-IRES activity. Moreover, silencing of these factors significantly suppressed CSFV-IRES activity. Thus, PKD1L3 and USP31 are host factors associated with the functions of FMDV- and CSFV-IRES elements.
Collapse
Affiliation(s)
- Yutaro Ide
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Bouchra Kitab
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Nobumasa Ito
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Riai Okamoto
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yui Tamura
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Takafumi Matsui
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yoshihiro Sakoda
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, 060-0818, Japan
| | - Kyoko Tsukiyama-Kohara
- Transboundary Animal Disease Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan. .,Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima, 890-0065, Japan.
| |
Collapse
|
4
|
Tan B, Giangaspero M, Sun N, Jin Y, Liu K, Wang Q, Cheng S, Wang Y, Zhang S. Antiviral Effect of Ginsenoside Rb2 and Rb3 Against Bovine Viral Diarrhea Virus and Classical Swine Fever Virus in vitro. Front Vet Sci 2021; 8:764909. [PMID: 34957281 PMCID: PMC8692705 DOI: 10.3389/fvets.2021.764909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
Bovine viral diarrhea virus (BVDV) and classical swine fever virus (CSFV) are members of the genus Pestivirus that cause disease in wild and domestic animals and are responsible for extensive economic losses of livestock and biological industry. BVDV is also a significant laboratory contaminant. Currently, no effective antiviral therapeutics are available to control their infection. Ginsenosides, as major pharmacological ingredients in the plants of ginseng, have various biological activities. In the present work, the antiviral activity of 9 ginsenosides and 3 other saponins from Araliaceae plants was investigated against Pestivirus. Ginsenoside Rb2 and Rb3 showed low cytotoxicity and obvious antiviral effect. They were able to inhibit the replication and proliferation of BVDV and CSFV. In addition, our results suggest that the possible antiviral mechanism of Rb2 might be related to its ability to affect the translation of these viruses. Obtained results suggest that ginsenoside Rb2 and Rb3 have a potential for effective treatment against Pestivirus infection.
Collapse
Affiliation(s)
- Bin Tan
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | | | - Na Sun
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Yinping Jin
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Kexin Liu
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Qianying Wang
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Shipeng Cheng
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Yingping Wang
- National and Local Joint Engineering Research Center for Ginseng Breeding and Development, Changchun, China
| | - Shuqin Zhang
- Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, China
| |
Collapse
|
5
|
Wang N, Wang H, Shi J, Li C, Liu X, Fan J, Sun C, Cameron CE, Qi H, Yu L. The Stem-Loop I of Senecavirus A IRES Is Essential for Cap-Independent Translation Activity and Virus Recovery. Viruses 2021; 13:v13112159. [PMID: 34834966 PMCID: PMC8619302 DOI: 10.3390/v13112159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/07/2021] [Accepted: 10/22/2021] [Indexed: 11/29/2022] Open
Abstract
Senecavirus A (SVA) is a picornavirus that causes vesicular disease in swine and the only member of the Senecavirus genus. Like in all members of Picornaviridae, the 5′ untranslated region (5’UTR) of SVA contains an internal ribosome entry site (IRES) that initiates cap-independent translation. For example, the replacement of the IRES of foot-and-mouth disease virus (FMDV) with its relative bovine rhinitis B virus (BRBV) affects the viral translation efficiency and virulence. Structurally, the IRES from SVA resembles that of hepatitis C virus (HCV), a flavivirus. Given the roles of the IRES in cap-independent translation for picornaviruses, we sought to functionally characterize the IRES of this genus by studying chimeric viruses generated by exchanging the native SVA IRES with that of HCV either entirely or individual domains. First, the results showed that a chimeric SVA virus harboring the IRES from HCV, H-SVA, is viable and replicated normally in rodent-derived BHK-21 cells but displays replication defects in porcine-derived ST cells. In the generation of chimeric viruses in which domain-specific elements from SVA were replaced with those of HCV, we identified an essential role for the stem-loop I element for IRES activity and recombinant virus recovery. Furthermore, a series of stem-loop I mutants allowed us to functionally characterize discrete IRES regions and correlate impaired IRES activities, using reporter systems with our inability to recover recombinant viruses in two different cell types. Interestingly, mutant viruses harboring partially defective IRES were viable. However, no discernable replication differences were observed, relative to the wild-type virus, suggesting the cooperation of additional factors, such as intermolecular viral RNA interactions, act in concert in regulating IRES-dependent translation during infection. Altogether, we found that the stem-loop I of SVA is an essential element for IRES-dependent translation activity and viral replication.
Collapse
Affiliation(s)
- Nana Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Haiwei Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Jiabao Shi
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Chen Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Xinran Liu
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Junhao Fan
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Chao Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
| | - Craig E. Cameron
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27516, USA;
| | - Hong Qi
- Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, School of Environment, Harbin 150090, China
- Correspondence: (H.Q.); (L.Y.); Tel.: +86-451-51051738 (L.Y.)
| | - Li Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China; (N.W.); (H.W.); (J.S.); (C.L.); (J.F.); (C.S.)
- Correspondence: (H.Q.); (L.Y.); Tel.: +86-451-51051738 (L.Y.)
| |
Collapse
|
6
|
van den Akker GGH, Zacchini F, Housmans BAC, van der Vloet L, Caron MMJ, Montanaro L, Welting TJM. Current Practice in Bicistronic IRES Reporter Use: A Systematic Review. Int J Mol Sci 2021; 22:5193. [PMID: 34068921 PMCID: PMC8156625 DOI: 10.3390/ijms22105193] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/05/2021] [Accepted: 05/12/2021] [Indexed: 12/26/2022] Open
Abstract
Bicistronic reporter assays have been instrumental for transgene expression, understanding of internal ribosomal entry site (IRES) translation, and identification of novel cap-independent translational elements (CITE). We observed a large methodological variability in the use of bicistronic reporter assays and data presentation or normalization procedures. Therefore, we systematically searched the literature for bicistronic IRES reporter studies and analyzed methodological details, data visualization, and normalization procedures. Two hundred fifty-seven publications were identified using our search strategy (published 1994-2020). Experimental studies on eukaryotic adherent cell systems and the cell-free translation assay were included for further analysis. We evaluated the following methodological details for 176 full text articles: the bicistronic reporter design, the cell line or type, transfection methods, and time point of analyses post-transfection. For the cell-free translation assay, we focused on methods of in vitro transcription, type of translation lysate, and incubation times and assay temperature. Data can be presented in multiple ways: raw data from individual cistrons, a ratio of the two, or fold changes thereof. In addition, many different control experiments have been suggested when studying IRES-mediated translation. In addition, many different normalization and control experiments have been suggested when studying IRES-mediated translation. Therefore, we also categorized and summarized their use. Our unbiased analyses provide a representative overview of bicistronic IRES reporter use. We identified parameters that were reported inconsistently or incompletely, which could hamper data reproduction and interpretation. On the basis of our analyses, we encourage adhering to a number of practices that should improve transparency of bicistronic reporter data presentation and improve methodological descriptions to facilitate data replication.
Collapse
Affiliation(s)
- Guus Gijsbertus Hubert van den Akker
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Federico Zacchini
- Department of Experimental, Diagnostic and Specialty Medicine, Bologna University, I-40138 Bologna, Italy; (F.Z.); (L.M.)
- Centro di Ricerca Biomedica Applicata—CRBA, Bologna University, Policlinico di Sant’Orsola, I-40138 Bologna, Italy
| | - Bas Adrianus Catharina Housmans
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Laura van der Vloet
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Marjolein Maria Johanna Caron
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| | - Lorenzo Montanaro
- Department of Experimental, Diagnostic and Specialty Medicine, Bologna University, I-40138 Bologna, Italy; (F.Z.); (L.M.)
- Centro di Ricerca Biomedica Applicata—CRBA, Bologna University, Policlinico di Sant’Orsola, I-40138 Bologna, Italy
- Programma Dipartimentale in Medicina di Laboratorio, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Albertoni 15, I-40138 Bologna, Italy
| | - Tim Johannes Maria Welting
- Department of Orthopedic Surgery, Maastricht University, Medical Center+, 6229 ER Maastricht, The Netherlands; (G.G.H.v.d.A.); (B.A.C.H.); (L.v.d.V.); (M.M.J.C.)
| |
Collapse
|
7
|
Fahnøe U, Deng Y, Davids NA, Lohse L, Bukh J, Belsham GJ, Rasmussen TB. Identification of specific amino acid residues in the border disease virus glycoprotein E2 that modify virus growth in pig cells but not in sheep cells. J Gen Virol 2021; 101:1170-1181. [PMID: 32857690 DOI: 10.1099/jgv.0.001483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Border disease virus (BDV) envelope glycoprotein E2 is required for entry into cells and is a determinant of host tropism for sheep and pig cells. Here, we describe adaptive changes in the BDV E2 protein that modify virus replication in pig cells. To achieve this, two BDV isolates, initially collected from a pig and a sheep on the same farm, were passaged in primary sheep and pig cells in parallel with a rescued variant of the pig virus derived from a cloned full-length BDV cDNA. The pig isolate and the rescued virus shared the same amino acid sequence, but the sheep isolate differed at ten residues, including two substitutions in E2 (K771E and Y925H). During serial passage in cells, the viruses displayed clear selectivity for growth in sheep cells; only the cDNA-derived virus adapted to grow in pig cells. Sequencing revealed an amino acid substitution (Q739R) in the E2 domain DA of this rescued virus. Adaptation at the same residue (Q739K/Q739R) was also observed after passaging of the pig isolate in sheep cells. Use of reverse genetics confirmed that changing residue Q739 to R or K (each positively charged) was sufficient to achieve adaptation to pig cells. Furthermore, this change in host tropism was suppressed if Q739R was combined with K771E. Another substitution (Q728R), conferring an additional positive charge, acquired during passaging, restored the growth of the Q739R/K771E variant. Overall, this study provided evidence that specific, positively charged, residues in the E2 domain DA are crucial for pig-cell tropism of BDV.
Collapse
Affiliation(s)
- Ulrik Fahnøe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark.,DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Yu Deng
- School of Animal Science, Xichang College, Xichang 615013, PR China.,DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Nana A Davids
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.,DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Louise Lohse
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.,DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Graham J Belsham
- Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 15, DK-1870 Frederiksberg C, Denmark.,DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark.,Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| |
Collapse
|
8
|
Analysis of Virus Population Profiles within Pigs Infected with Virulent Classical Swine Fever Viruses: Evidence for Bottlenecks in Transmission but Absence of Tissue-Specific Virus Variants. J Virol 2020; 94:JVI.01119-20. [PMID: 32699086 DOI: 10.1128/jvi.01119-20] [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: 06/04/2020] [Accepted: 07/14/2020] [Indexed: 11/20/2022] Open
Abstract
Classical swine fever virus (CSFV) contains a specific motif within the E2 glycoprotein that differs between strains of different virulence. In the highly virulent CSFV strain Koslov, this motif comprises residues S763/L764 in the polyprotein. However, L763/P764 represent the predominant alleles in published CSFV genomes. In this study, changes were introduced into the CSFV strain Koslov (here called vKos_SL) to generate modified CSFVs with substitutions at residues 763 and/or 764 (vKos_LL, vKos_SP, and vKos_LP). The properties of these mutant viruses, in comparison to those of vKos_SL, were determined in pigs. Each of the viruses was virulent and induced typical clinical signs of CSF, but the vKos_LP strain produced them significantly earlier. Full-length CSFV cDNA amplicons (12.3 kb) derived from sera of infected pigs were deep sequenced and cloned to reveal the individual haplotypes that contributed to the single-nucleotide polymorphism (SNP) profiles observed in the virus population. The SNP profiles for vKos_SL and vKos_LL displayed low-level heterogeneity across the entire genome, whereas vKos_SP and vKos_LP displayed limited diversity with a few high-frequency SNPs. This indicated that vKos_SL and vKos_LL exhibited a higher level of fitness in the host and more stability at the consensus level, whereas several consensus changes were observed in the vKos_SP and vKos_LP sequences, pointing to adaptation. For each virus, only a subset of the variants present within the virus inoculums were maintained in the infected pigs. No clear tissue-dependent quasispecies differentiation occurred within inoculated pigs; however, clear evidence for transmission bottlenecks to contact animals was observed, with subsequent loss of sequence diversity.IMPORTANCE The surface-exposed E2 protein of classical swine fever virus is required for its interaction with host cells. A short motif within this protein varies between strains of different virulence. The importance of two particular amino acid residues in determining the properties of a highly virulent strain of the virus has been analyzed. Each of the different viruses tested proved highly virulent, but one of them produced earlier, but not more severe, disease. By analyzing the virus genomes present within infected pigs, it was found that the viruses which replicated within inoculated animals were only a subset of those within the virus inoculum. Furthermore, following contact transmission, it was shown that a very restricted set of viruses had transferred between animals. There were no significant differences in the virus populations present in various tissues of the infected animals. These results indicate mechanisms of virus population change during transmission between animals.
Collapse
|
9
|
Arhab Y, Bulakhov AG, Pestova TV, Hellen CU. Dissemination of Internal Ribosomal Entry Sites (IRES) Between Viruses by Horizontal Gene Transfer. Viruses 2020; 12:E612. [PMID: 32512856 PMCID: PMC7354566 DOI: 10.3390/v12060612] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 12/19/2022] Open
Abstract
Members of Picornaviridae and of the Hepacivirus, Pegivirus and Pestivirus genera of Flaviviridae all contain an internal ribosomal entry site (IRES) in the 5'-untranslated region (5'UTR) of their genomes. Each class of IRES has a conserved structure and promotes 5'-end-independent initiation of translation by a different mechanism. Picornavirus 5'UTRs, including the IRES, evolve independently of other parts of the genome and can move between genomes, most commonly by intratypic recombination. We review accumulating evidence that IRESs are genetic entities that can also move between members of different genera and even between families. Type IV IRESs, first identified in the Hepacivirus genus, have subsequently been identified in over 25 genera of Picornaviridae, juxtaposed against diverse coding sequences. In several genera, members have either type IV IRES or an IRES of type I, II or III. Similarly, in the genus Pegivirus, members contain either a type IV IRES or an unrelated type; both classes of IRES also occur in members of the genus Hepacivirus. IRESs utilize different mechanisms, have different factor requirements and contain determinants of viral growth, pathogenesis and cell type specificity. Their dissemination between viruses by horizontal gene transfer has unexpectedly emerged as an important facet of viral evolution.
Collapse
Affiliation(s)
| | | | | | - Christopher U.T. Hellen
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA; (Y.A.); (A.G.B.); (T.V.P.)
| |
Collapse
|
10
|
Chicken eEF1α is a Critical Factor for the Polymerase Complex Activity of Very Virulent Infectious Bursal Disease Virus. Viruses 2020; 12:v12020249. [PMID: 32102240 PMCID: PMC7077273 DOI: 10.3390/v12020249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Infectious bursal disease (IBD) is an immunosuppressive, highly contagious, and lethal disease of young chickens caused by IBD virus (IBDV). It results in huge economic loss to the poultry industry worldwide. Infection caused by very virulent IBDV (vvIBDV) strains results in high mortality in young chicken flocks. However, the replication characteristics of vvIBDV are not well studied. Publications have shown that virus protein 3 (VP3) binds to VP1 and viral double-stranded RNA, and together they form a ribonucleoprotein complex that plays a key role in virus replication. In this study, vvIBDV VP3 was used to identify host proteins potentially involved in modulating vvIBDV replication. Chicken eukaryotic translation elongation factor 1α (cheEF1α) was chosen to further investigate effects on vvIBDV replication. By small interfering RNA-mediated cheEF1α knockdown, we demonstrated the possibility of significantly reducing viral polymerase activity, with a subsequent reduction in virus yields. Conversely, over-expression of cheEF1α significantly increased viral polymerase activity and virus replication. Further study confirmed that cheEF1α interacted only with vvIBDV VP3 but not with attenuated IBDV (aIBDV) VP3. Furthermore, the amino acids at the N- and C-termini were important in the interaction between vvIBDV VP3 and cheEF1α. Domain III was essential for interactions between cheEF1α and vvIBDV VP3. In summary, cheEF1α enhances vvIBDV replication by promoting the activity of virus polymerase. Our study indicates cheEF1α is a potential target for limiting vvIBDV infection.
Collapse
|
11
|
mTORC1 Negatively Regulates the Replication of Classical Swine Fever Virus Through Autophagy and IRES-Dependent Translation. iScience 2018; 3:87-101. [PMID: 30428332 PMCID: PMC6137324 DOI: 10.1016/j.isci.2018.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/06/2018] [Accepted: 03/29/2018] [Indexed: 02/07/2023] Open
Abstract
Classical swine fever virus (CSFV) can utilize diverse host signaling pathways for its replication; however, the cross talk between mammalian target of rapamycin (mTOR) and CSFV remains unknown. Here, we describe the potential role of mTOR complex 1 (mTORC1) in promoting CSFV replication via virus-induced hypophosphorylation of the Akt/mTORC1/S6 pathway, especially at an early stage of viral infection. Conversely, activation of mTORC1 inhibited the replication of CSFV. Furthermore, we revealed the underlying mechanisms of mTORC1 pathway in mediating CSFV replication; in addition, our data also showed that CSFV-induced transient inhibition of mTORC1 elicited a negative feedback activation of PI3K/Akt/mTORC1pathway, likely contributing to maintain the dynamic balance between viral replication and host cell survival. This study has provided strong evidence showing how CSFV utilizes mTORC1 pathway for viral replication at an early stage in the viral replicative cycle and how the mTORC1 rescues itself by eliciting a feedback loop to limit viral replication and maintain cell survival. Akt/mTORC1 pathway negatively regulates the replication of CSFV CSFV induces autophagy for viral replication in an mTORC1/ULK1-dependent manner CSFV enhances the translation of viral proteins in an mTORC1/S6K1/eIF3-dependent manner Feedback activation of Akt/mTORC1 equilibrates viral replication and cell survival
Collapse
|
12
|
Willcocks MM, Zaini S, Chamond N, Ulryck N, Allouche D, Rajagopalan N, Davids NA, Fahnøe U, Hadsbjerg J, Rasmussen TB, Roberts LO, Sargueil B, Belsham GJ, Locker N. Distinct roles for the IIId2 sub-domain in pestivirus and picornavirus internal ribosome entry sites. Nucleic Acids Res 2018; 45:13016-13028. [PMID: 29069411 PMCID: PMC5727462 DOI: 10.1093/nar/gkx991] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 10/12/2017] [Indexed: 01/23/2023] Open
Abstract
Viral internal ribosomes entry site (IRES) elements coordinate the recruitment of the host translation machinery to direct the initiation of viral protein synthesis. Within hepatitis C virus (HCV)-like IRES elements, the sub-domain IIId(1) is crucial for recruiting the 40S ribosomal subunit. However, some HCV-like IRES elements possess an additional sub-domain, termed IIId2, whose function remains unclear. Herein, we show that IIId2 sub-domains from divergent viruses have different functions. The IIId2 sub-domain present in Seneca valley virus (SVV), a picornavirus, is dispensable for IRES activity, while the IIId2 sub-domains of two pestiviruses, classical swine fever virus (CSFV) and border disease virus (BDV), are required for 80S ribosomes assembly and IRES activity. Unlike in SVV, the deletion of IIId2 from the CSFV and BDV IRES elements impairs initiation of translation by inhibiting the assembly of 80S ribosomes. Consequently, this negatively affects the replication of CSFV and BDV. Finally, we show that the SVV IIId2 sub-domain is required for efficient viral RNA synthesis and growth of SVV, but not for IRES function. This study sheds light on the molecular evolution of viruses by clearly demonstrating that conserved RNA structures, within distantly related RNA viruses, have acquired different roles in the virus life cycles.
Collapse
Affiliation(s)
- Margaret M Willcocks
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Salmah Zaini
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Nathalie Chamond
- Faculté des Sciences Pharmaceutiques et Biologiques, UMR8015, Université Paris Descartes, Paris, France
| | - Nathalie Ulryck
- Faculté des Sciences Pharmaceutiques et Biologiques, UMR8015, Université Paris Descartes, Paris, France
| | - Delphine Allouche
- Faculté des Sciences Pharmaceutiques et Biologiques, UMR8015, Université Paris Descartes, Paris, France
| | - Noemie Rajagopalan
- Faculté des Sciences Pharmaceutiques et Biologiques, UMR8015, Université Paris Descartes, Paris, France
| | - Nana A Davids
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Ulrik Fahnøe
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Johanne Hadsbjerg
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Lisa O Roberts
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK.,School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Bruno Sargueil
- Faculté des Sciences Pharmaceutiques et Biologiques, UMR8015, Université Paris Descartes, Paris, France
| | - Graham J Belsham
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, UK
| |
Collapse
|
13
|
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]
|
14
|
Gou H, Zhao M, Yuan J, Xu H, Ding H, Chen J. Metabolic Profiles in Cell Lines Infected with Classical Swine Fever Virus. Front Microbiol 2017; 8:691. [PMID: 28473819 PMCID: PMC5397473 DOI: 10.3389/fmicb.2017.00691] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 04/04/2017] [Indexed: 12/22/2022] Open
Abstract
Viruses require energy and biosynthetic precursors from host cells for replication. An understanding of the metabolic interplay between classical swine fever virus (CSFV) and host cells is important for exploring the complex pathological mechanisms of classical swine fever (CSF). In the current study, and for the first time, we utilized an approach involving gas chromatography coupled with mass spectrometry (GC-MS) to examine the metabolic profiles within PK-15 and 3D4/2 cells infected with CSFV. The differential metabolites of PK-15 cells caused by CSFV infection mainly included the decreased levels of glucose 6-phosphate [fold change (FC) = −1.94)] and glyceraldehyde-3-phosphate (FC = −1.83) during glycolysis, ribulose 5-phosphate (FC = −1.51) in the pentose phosphate pathway, guanosine (FC = −1.24) and inosine (FC = −1.16) during purine biosynthesis, but the increased levels of 2-ketoisovaleric acid (FC = 0.63) during the citrate cycle, and ornithine (FC = 0.56) and proline (FC = 0.62) during arginine and proline metabolism. However, metabolite changes caused by CSFV infection in 3D4/2 cells included the reduced glyceraldehyde-3-phosphate (FC = −0.77) and pyruvic acid (FC = −1.42) during glycolysis, 2-ketoglutaric acid (FC = −1.52) in the citrate cycle, and the elevated cytosine (FC = 2.15) during pyrimidine metabolism. Our data showed that CSFV might rebuild cellular metabolic programs, thus aiding viral replication. These findings may be important in developing targets for new biomarkers for the diagnosis and identification of enzyme inhibitors or metabolites as antiviral drugs, or screening viral gene products as vaccines.
Collapse
Affiliation(s)
- Hongchao Gou
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| | - Mingqiu Zhao
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| | - Jin Yuan
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| | - Hailuan Xu
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| | - Hongxing Ding
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural UniversityGuangzhou, China
| |
Collapse
|
15
|
Hadsbjerg J, Friis MB, Fahnøe U, Nielsen J, Belsham GJ, Rasmussen TB. Sequence adaptations during growth of rescued classical swine fever viruses in cell culture and within infected pigs. Vet Microbiol 2016; 192:123-134. [PMID: 27527774 DOI: 10.1016/j.vetmic.2016.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 06/24/2016] [Accepted: 07/06/2016] [Indexed: 02/05/2023]
Abstract
Classical swine fever virus (CSFV) causes an economically important disease of swine. Four different viruses were rescued from full-length cloned cDNAs derived from the Paderborn strain of CSFV. Three of these viruses had been modified by mutagenesis (with 7 or 8 nt changes) within stem 2 of the subdomain IIIf of the internal ribosome entry site (IRES) that directs the initiation of protein synthesis. Rescued viruses were inoculated into pigs. The rescued vPader10 virus, without modifications in the IRES, induced clinical disease in pigs that was very similar to that observed previously with the parental field strain and transmission to in-contact pigs occurred. Two sequence reversions, in the NS2 and NS5B coding regions, became dominant within the virus populations in these infected pigs. Rescued viruses, with mutant IRES elements, did not induce disease and only very limited circulation of viral RNA could be detected. However, the animals inoculated with these mutant viruses seroconverted against CSFV. Thus, these mutant viruses were highly attenuated in vivo. All 4 rescued viruses were also passaged up to 20 times in cell culture. Using full genome sequencing, the same two adaptations within each of four independent virus populations were observed that restored the coding sequence to that of the parental field strain. These adaptations occurred with different kinetics. The combination of reverse genetics and in depth, full genome sequencing provides a powerful approach to analyse virus adaptation and to identify key determinants of viral replication efficiency in cells and within host animals.
Collapse
Affiliation(s)
- Johanne Hadsbjerg
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Martin B Friis
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Ulrik Fahnøe
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Jens Nielsen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Graham J Belsham
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark.
| | - Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| |
Collapse
|
16
|
Guanylate-Binding Protein 1, an Interferon-Induced GTPase, Exerts an Antiviral Activity against Classical Swine Fever Virus Depending on Its GTPase Activity. J Virol 2016; 90:4412-4426. [PMID: 26889038 PMCID: PMC4836331 DOI: 10.1128/jvi.02718-15] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/11/2016] [Indexed: 12/11/2022] Open
Abstract
Many viruses trigger the type I interferon (IFN) pathway upon infection, resulting in the transcription of hundreds of interferon-stimulated genes (ISGs), which define the antiviral state of the host. Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), a highly contagious viral disease endangering the pig industry in many countries. However, anti-CSFV ISGs are poorly documented. Here we screened 20 ISGs that are commonly induced by type I IFNs against CSFV in lentivirus-delivered cell lines, resulting in the identification of guanylate-binding protein 1 (GBP1) as a potent anti-CSFV ISG. We observed that overexpression of GBP1, an IFN-induced GTPase, remarkably suppressed CSFV replication, whereas knockdown of endogenous GBP1 expression by small interfering RNAs significantly promoted CSFV growth. Furthermore, we demonstrated that GBP1 acted mainly on the early phase of CSFV replication and inhibited the translation efficiency of the internal ribosome entry site of CSFV. In addition, we found that GBP1 was upregulated at the transcriptional level in CSFV-infected PK-15 cells and in various organs of CSFV-infected pigs. Coimmunoprecipitation and glutathione S-transferase (GST) pulldown assays revealed that GBP1 interacted with the NS5A protein of CSFV, and this interaction was mapped in the N-terminal globular GTPase domain of GBP1. Interestingly, the K51 of GBP1, which is crucial for its GTPase activity, was essential for the inhibition of CSFV replication. We showed further that the NS5A-GBP1 interaction inhibited GTPase activity, which was critical for its antiviral effect. Taking our findings together, GBP1 is an anti-CSFV ISG whose action depends on its GTPase activity. IMPORTANCE Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), an economically important viral disease affecting the pig industry in many countries. To date, only a few host restriction factors against CSFV, including interferon-stimulated genes (ISGs), have been characterized. Using a minilibrary of porcine ISGs, we identify porcine guanylate-binding protein 1 (GBP1) as a potent antiviral ISG against CSFV. We further show that the anti-CSFV action of GBP1 depends on its GTPase activity. The K51 of GBP1, critical for its GTPase activity, is essential for the antiviral action of GBP1 against CSFV replication, and the binding of the NS5A protein to GBP1 antagonizes the GTPase activity and thus the antiviral effect. This study will facilitate the development of anti-CSFV therapeutic agents by targeting host factors and may provide a new strategy for the control of CSF.
Collapse
|
17
|
Live Cell Reporter Systems for Positive-Sense Single Strand RNA Viruses. Appl Biochem Biotechnol 2016; 178:1567-85. [PMID: 26728654 PMCID: PMC7091396 DOI: 10.1007/s12010-015-1968-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/22/2015] [Indexed: 01/09/2023]
Abstract
Cell-based reporter systems have facilitated studies of viral replication and pathogenesis, virus detection, and drug susceptibility testing. There are three types of cell-based reporter systems that express certain reporter protein for positive-sense single strand RNA virus infections. The first type is classical reporter system, which relies on recombinant virus, reporter virus particle, or subgenomic replicon. During infection with the recombinant virus or reporter virus particle, the reporter protein is expressed and can be detected in real time in a dose-dependent manner. Using subgenomic replicon, which are genetically engineered viral RNA molecules that are capable of replication but incapable of producing virions, the translation and replication of the replicon could be tracked by the accumulation of reporter protein. The second type of reporter system involves genetically engineered cells bearing virus-specific protease cleavage sequences, which can sense the incoming viral protease. The third type is based on viral replicase, which can report the specific virus infection via detection of the incoming viral replicase. This review specifically focuses on the major technical breakthroughs in the design of cell-based reporter systems and the application of these systems to the further understanding and control of viruses over the past few decades.
Collapse
|
18
|
Fahnøe U, Pedersen AG, Dräger C, Orton RJ, Blome S, Höper D, Beer M, Rasmussen TB. Creation of Functional Viruses from Non-Functional cDNA Clones Obtained from an RNA Virus Population by the Use of Ancestral Reconstruction. PLoS One 2015; 10:e0140912. [PMID: 26485566 PMCID: PMC4613144 DOI: 10.1371/journal.pone.0140912] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/01/2015] [Indexed: 02/05/2023] Open
Abstract
RNA viruses have the highest known mutation rates. Consequently it is likely that a high proportion of individual RNA virus genomes, isolated from an infected host, will contain lethal mutations and be non-functional. This is problematic if the aim is to clone and investigate high-fitness, functional cDNAs and may also pose problems for sequence-based analysis of viral evolution. To address these challenges we have performed a study of the evolution of classical swine fever virus (CSFV) using deep sequencing and analysis of 84 full-length cDNA clones, each representing individual genomes from a moderately virulent isolate. In addition to here being used as a model for RNA viruses generally, CSFV has high socioeconomic importance and remains a threat to animal welfare and pig production. We find that the majority of the investigated genomes are non-functional and only 12% produced infectious RNA transcripts. Full length sequencing of cDNA clones and deep sequencing of the parental population identified substitutions important for the observed phenotypes. The investigated cDNA clones were furthermore used as the basis for inferring the sequence of functional viruses. Since each unique clone must necessarily be the descendant of a functional ancestor, we hypothesized that it should be possible to produce functional clones by reconstructing ancestral sequences. To test this we used phylogenetic methods to infer two ancestral sequences, which were then reconstructed as cDNA clones. Viruses rescued from the reconstructed cDNAs were tested in cell culture and pigs. Both reconstructed ancestral genomes proved functional, and displayed distinct phenotypes in vitro and in vivo. We suggest that reconstruction of ancestral viruses is a useful tool for experimental and computational investigations of virulence and viral evolution. Importantly, ancestral reconstruction can be done even on the basis of a set of sequences that all correspond to non-functional variants.
Collapse
Affiliation(s)
- Ulrik Fahnøe
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave, Denmark
- Center for Biological Sequence Analysis, DTU Systems Biology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Anders Gorm Pedersen
- Center for Biological Sequence Analysis, DTU Systems Biology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Carolin Dräger
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Richard J Orton
- Institute of Biodiversity, Animal Health, and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- MRC–University of Glasgow Centre for Virus Research, Institute of Infection, Inflammation and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Dirk Höper
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave, Denmark
- * E-mail:
| |
Collapse
|
19
|
Li S, Feng S, Wang JH, He WR, Qin HY, Dong H, Li LF, Yu SX, Li Y, Qiu HJ. eEF1A Interacts with the NS5A Protein and Inhibits the Growth of Classical Swine Fever Virus. Viruses 2015; 7:4563-81. [PMID: 26266418 PMCID: PMC4576194 DOI: 10.3390/v7082833] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/03/2015] [Accepted: 08/05/2015] [Indexed: 12/23/2022] Open
Abstract
The NS5A protein of classical swine fever virus (CSFV) is involved in the RNA synthesis and viral replication. However, the NS5A-interacting cellular proteins engaged in the CSFV replication are poorly defined. Using yeast two-hybrid screen, the eukaryotic elongation factor 1A (eEF1A) was identified to be an NS5A-binding partner. The NS5A-eEF1A interaction was confirmed by coimmunoprecipitation, glutathione S-transferase (GST) pulldown and laser confocal microscopy assays. The domain I of eEF1A was shown to be critical for the NS5A-eEF1A interaction. Overexpression of eEF1A suppressed the CSFV growth markedly, and conversely, knockdown of eEF1A enhanced the CSFV replication significantly. Furthermore, eEF1A, as well as NS5A, was found to reduce the translation efficiency of the internal ribosome entry site (IRES) of CSFV in a dose-dependent manner, as demonstrated by luciferase reporter assay. Streptavidin pulldown assay revealed that eEF1A could bind to the CSFV IRES. Collectively, our results suggest that eEF1A interacts with NS5A and negatively regulates the growth of CSFV.
Collapse
Affiliation(s)
- Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China
| | - Shuo Feng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Jing-Han Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Wen-Rui He
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Hua-Yang Qin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Hong Dong
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Lian-Feng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Shao-Xiong Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Yongfeng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China.
| |
Collapse
|
20
|
Liu WJ, Yang YT, Zhao MQ, Dong XY, Gou HC, Pei JJ, Chen JD. PKR activation enhances replication of classical swine fever virus in PK-15 cells. Virus Res 2015; 204:47-57. [PMID: 25899421 PMCID: PMC7114430 DOI: 10.1016/j.virusres.2015.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/25/2015] [Accepted: 04/09/2015] [Indexed: 12/22/2022]
Abstract
CSFV infection triggers PKR and eIF2α protein phosphorylation. PKR overexpression stimulates viral replication. PKR depletion blocks eIF2α phosphorylation and suppresses viral replication. PKR depletion increases IFN-β, and enhances the antiviral effect of IFN.
Classical swine fever (CSF) is a highly contagious swine disease that is responsible for economic losses worldwide. Protein kinase R (PK)R is an important protein in the host viral response; however, the role of PKR in CSFV infection remains unknown. This issue was addressed in the present study using the PK-15 swine kidney cell line. We found that CSFV infection increased the phosphorylation of eukaryotic translation initiation factor (eIF)2α and its kinase PKR. However, the expression of viral proteins continued to increase. Furthermore, PKR overexpression enhanced CSFV replication, while PKR inhibition resulted in reduced CSFV replication and an increase in interferon (IFN) induction. In addition, PKR was responsible for eIF2α phosphorylation in CSFV-infected cells. These results suggest that the activation of PKR during CSFV infection is beneficial to the virus. The virus is able to commandeer the host cell's translation machinery for viral protein synthesis while evading innate immune defenses.
Collapse
Affiliation(s)
- Wen-Jun Liu
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - You-Tian Yang
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - Ming-Qiu Zhao
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - Xiao-Ying Dong
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - Hong-Chao Gou
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - Jing-Jing Pei
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China
| | - Jin-Ding Chen
- College of Veterinary Medicine, South China Agricultural University, 483 Wu Shan Road, Tian He District, Guangzhou 510642, China.
| |
Collapse
|
21
|
Asnani M, Kumar P, Hellen CUT. Widespread distribution and structural diversity of Type IV IRESs in members of Picornaviridae. Virology 2015; 478:61-74. [PMID: 25726971 DOI: 10.1016/j.virol.2015.02.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 01/13/2023]
Abstract
Picornavirus genomes contain internal ribosomal entry sites (IRESs) that promote end-independent translation initiation. Five structural classes of picornavirus IRES have been identified, but numerous IRESs remain unclassified. Here, previously unrecognized Type IV IRESs were identified in members of three proposed picornavirus genera (Limnipivirus, Pasivirus, Rafivirus) and four recognized genera (Kobuvirus, Megrivirus, Sapelovirus, Parechovirus). These IRESs are ~230-420 nucleotides long, reflecting heterogeneity outside a common structural core. Closer analysis yielded insights into evolutionary processes that have shaped contemporary IRESs. The presence of related IRESs in diverse genera supports the hypothesis that they are heritable genetic elements that spread by horizontal gene transfer. Recombination likely also accounts for the exchange of some peripheral subdomains, suggesting that IRES evolution involves incremental addition of elements to a pre-existing core. Nucleotide conservation is concentrated in ribosome-binding sites, and at the junction of helical domains, likely to ensure orientation of subdomains in an active conformation.
Collapse
Affiliation(s)
- Mukta Asnani
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Parimal Kumar
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Christopher U T Hellen
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA.
| |
Collapse
|
22
|
Rescue of the highly virulent classical swine fever virus strain “Koslov” from cloned cDNA and first insights into genome variations relevant for virulence. Virology 2014; 468-470:379-387. [DOI: 10.1016/j.virol.2014.08.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 07/07/2014] [Accepted: 08/21/2014] [Indexed: 11/18/2022]
|
23
|
Rasmussen TB, Risager PC, Fahnøe U, Friis MB, Belsham GJ, Höper D, Reimann I, Beer M. Efficient generation of recombinant RNA viruses using targeted recombination-mediated mutagenesis of bacterial artificial chromosomes containing full-length cDNA. BMC Genomics 2013; 14:819. [PMID: 24262008 PMCID: PMC3840674 DOI: 10.1186/1471-2164-14-819] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 11/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Infectious cDNA clones are a prerequisite for directed genetic manipulation of RNA viruses. Here, a strategy to facilitate manipulation and rescue of classical swine fever viruses (CSFVs) from full-length cDNAs present within bacterial artificial chromosomes (BACs) is described. This strategy allows manipulation of viral cDNA by targeted recombination-mediated mutagenesis within bacteria. RESULTS A new CSFV-BAC (pBeloR26) derived from the Riems vaccine strain has been constructed and subsequently modified in the E2 coding sequence, using the targeted recombination strategy to enable rescue of chimeric pestiviruses (vR26_E2gif and vR26_TAV) with potential as new marker vaccine candidates. Sequencing of the BACs revealed a high genetic stability during passages within bacteria. The complete genome sequences of rescued viruses, after extensive passages in mammalian cells showed that modifications in the E2 protein coding sequence were stably maintained. A single amino acid substitution (D3431G) in the RNA dependent RNA polymerase was observed in the rescued viruses vR26_E2gif and vR26, which was reversion to the parental Riems sequence. CONCLUSIONS These results show that targeted recombination-mediated mutagenesis provides a powerful tool for expediting the construction of novel RNA genomes and should be applicable to the manipulation of other RNA viruses.
Collapse
Affiliation(s)
- Thomas Bruun Rasmussen
- DTU National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771, Kalvehave, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Hepatitis-C-virus-like internal ribosome entry sites displace eIF3 to gain access to the 40S subunit. Nature 2013; 503:539-43. [PMID: 24185006 DOI: 10.1038/nature12658] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 09/13/2013] [Indexed: 12/12/2022]
Abstract
Hepatitis C virus (HCV) and classical swine fever virus (CSFV) messenger RNAs contain related (HCV-like) internal ribosome entry sites (IRESs) that promote 5'-end independent initiation of translation, requiring only a subset of the eukaryotic initiation factors (eIFs) needed for canonical initiation on cellular mRNAs. Initiation on HCV-like IRESs relies on their specific interaction with the 40S subunit, which places the initiation codon into the P site, where it directly base-pairs with eIF2-bound initiator methionyl transfer RNA to form a 48S initiation complex. However, all HCV-like IRESs also specifically interact with eIF3 (refs 2, 5-7, 9-12), but the role of this interaction in IRES-mediated initiation has remained unknown. During canonical initiation, eIF3 binds to the 40S subunit as a component of the 43S pre-initiation complex, and comparison of the ribosomal positions of eIF3 and the HCV IRES revealed that they overlap, so that their rearrangement would be required for formation of ribosomal complexes containing both components. Here we present a cryo-electron microscopy reconstruction of a 40S ribosomal complex containing eIF3 and the CSFV IRES. Remarkably, although the position and interactions of the CSFV IRES with the 40S subunit in this complex are similar to those of the HCV IRES in the 40S-IRES binary complex, eIF3 is completely displaced from its ribosomal position in the 43S complex, and instead interacts through its ribosome-binding surface exclusively with the apical region of domain III of the IRES. Our results suggest a role for the specific interaction of HCV-like IRESs with eIF3 in preventing ribosomal association of eIF3, which could serve two purposes: relieving the competition between the IRES and eIF3 for a common binding site on the 40S subunit, and reducing formation of 43S complexes, thereby favouring translation of viral mRNAs.
Collapse
|
25
|
Risager PC, Fahnøe U, Gullberg M, Rasmussen TB, Belsham GJ. Analysis of classical swine fever virus RNA replication determinants using replicons. J Gen Virol 2013; 94:1739-1748. [PMID: 23580431 DOI: 10.1099/vir.0.052688-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Self-replicating RNAs (replicons), with or without reporter gene sequences, derived from the genome of the Paderborn strain of classical swine fever virus (CSFV) have been produced. The full-length viral cDNA, propagated within a bacterial artificial chromosome, was modified by targeted recombination within Escherichia coli. RNA transcripts were produced in vitro and introduced into cells by electroporation. The translation and replication of the replicon RNAs could be followed by the accumulation of luciferase (from Renilla reniformis or Gaussia princeps) protein expression (where appropriate), as well as by detection of CSFV NS3 protein production within the cells. Inclusion of the viral E2 coding region within the replicon was advantageous for replication efficiency. Production of chimeric RNAs, substituting the NS2 and NS3 coding regions (as a unit) from the Paderborn strain with the equivalent sequences from the highly virulent Koslov strain or the vaccine strain Riems, blocked replication. However, replacing the Paderborn NS5B coding sequence with the RNA polymerase coding sequence from the Koslov strain greatly enhanced expression of the reporter protein from the replicon. In contrast, replacement with the Riems NS5B sequence significantly impaired replication efficiency. Thus, these replicons provide a system for determining specific regions of the CSFV genome required for genome replication without the constraints of maintaining infectivity.
Collapse
Affiliation(s)
- Peter Christian Risager
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Ulrik Fahnøe
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Maria Gullberg
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Thomas Bruun Rasmussen
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| | - Graham J Belsham
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark
| |
Collapse
|