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Zhang X, Sridharan S, Zagoriy I, Eugster Oegema C, Ching C, Pflaesterer T, Fung HKH, Becher I, Poser I, Müller CW, Hyman AA, Savitski MM, Mahamid J. Molecular mechanisms of stress-induced reactivation in mumps virus condensates. Cell 2023; 186:1877-1894.e27. [PMID: 37116470 PMCID: PMC10156176 DOI: 10.1016/j.cell.2023.03.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 09/21/2022] [Accepted: 03/14/2023] [Indexed: 04/30/2023]
Abstract
Negative-stranded RNA viruses can establish long-term persistent infection in the form of large intracellular inclusions in the human host and cause chronic diseases. Here, we uncover how cellular stress disrupts the metastable host-virus equilibrium in persistent infection and induces viral replication in a culture model of mumps virus. Using a combination of cell biology, whole-cell proteomics, and cryo-electron tomography, we show that persistent viral replication factories are dynamic condensates and identify the largely disordered viral phosphoprotein as a driver of their assembly. Upon stress, increased phosphorylation of the phosphoprotein at its interaction interface with the viral polymerase coincides with the formation of a stable replication complex. By obtaining atomic models for the authentic mumps virus nucleocapsid, we elucidate a concomitant conformational change that exposes the viral genome to its replication machinery. These events constitute a stress-mediated switch within viral condensates that provide an environment to support upregulation of viral replication.
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Affiliation(s)
- Xiaojie Zhang
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Sindhuja Sridharan
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Christina Eugster Oegema
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Cyan Ching
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Tim Pflaesterer
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Herman K H Fung
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Isabelle Becher
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Mikhail M Savitski
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany; Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
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2
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Sugrue E, Wickenhagen A, Mollentze N, Aziz MA, Sreenu VB, Truxa S, Tong L, da Silva Filipe A, Robertson DL, Hughes J, Rihn SJ, Wilson SJ. The apparent interferon resistance of transmitted HIV-1 is possibly a consequence of enhanced replicative fitness. PLoS Pathog 2022; 18:e1010973. [PMID: 36399512 PMCID: PMC9718408 DOI: 10.1371/journal.ppat.1010973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 12/02/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022] Open
Abstract
HIV-1 transmission via sexual exposure is an inefficient process. When transmission does occur, newly infected individuals are colonized by the descendants of either a single virion or a very small number of establishing virions. These transmitted founder (TF) viruses are more interferon (IFN)-resistant than chronic control (CC) viruses present 6 months after transmission. To identify the specific molecular defences that make CC viruses more susceptible to the IFN-induced 'antiviral state', we established a single pair of fluorescent TF and CC viruses and used arrayed interferon-stimulated gene (ISG) expression screening to identify candidate antiviral effectors. However, we observed a relatively uniform ISG resistance of transmitted HIV-1, and this directed us to investigate possible underlying mechanisms. Simple simulations, where we varied a single parameter, illustrated that reduced growth rate could possibly underly apparent interferon sensitivity. To examine this possibility, we closely monitored in vitro propagation of a model TF/CC pair (closely matched in replicative fitness) over a targeted range of IFN concentrations. Fitting standard four-parameter logistic growth models, in which experimental variables were regressed against growth rate and carrying capacity, to our in vitro growth curves, further highlighted that small differences in replicative growth rates could recapitulate our in vitro observations. We reasoned that if growth rate underlies apparent interferon resistance, transmitted HIV-1 would be similarly resistant to any growth rate inhibitor. Accordingly, we show that two transmitted founder HIV-1 viruses are relatively resistant to antiretroviral drugs, while their matched chronic control viruses were more sensitive. We propose that, when present, the apparent IFN resistance of transmitted HIV-1 could possibly be explained by enhanced replicative fitness, as opposed to specific resistance to individual IFN-induced defences. However, further work is required to establish how generalisable this mechanism of relative IFN resistance might be.
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Affiliation(s)
- Elena Sugrue
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Arthur Wickenhagen
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Nardus Mollentze
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
- School of Biodiversity, One Health & Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Muhamad Afiq Aziz
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Vattipally B. Sreenu
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Sven Truxa
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
- Division of Systems Immunology and Single Cell Biology, German Cancer Research Center, Heidelberg, Germany
| | - Lily Tong
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Ana da Silva Filipe
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - David L. Robertson
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Joseph Hughes
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Suzannah J. Rihn
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Sam J. Wilson
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
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3
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Briggs K, Wang L, Nagashima K, Zengel J, Tripp RA, He B. Regulation of Mumps Virus Replication and Transcription by Kinase RPS6KB1. J Virol 2020; 94:JVI.00387-20. [PMID: 32295907 PMCID: PMC7307103 DOI: 10.1128/jvi.00387-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/04/2020] [Indexed: 02/07/2023] Open
Abstract
Mumps virus (MuV) caused the most viral meningitis before mass immunization. Unfortunately, MuV has reemerged in the United States in the past several years. MuV is a member of the genus Rubulavirus, in the family Paramyxoviridae, and has a nonsegmented negative-strand RNA genome. The viral RNA-dependent RNA polymerase (vRdRp) of MuV consists of the large protein (L) and the phosphoprotein (P), while the nucleocapsid protein (NP) encapsulates the viral RNA genome. These proteins make up the replication and transcription machinery of MuV. The P protein is phosphorylated by host kinases, and its phosphorylation is important for its function. In this study, we performed a large-scale small interfering RNA (siRNA) screen targeting host kinases that regulated MuV replication. The human kinase ribosomal protein S6 kinase beta-1 (RPS6KB1) was shown to play a role in MuV replication and transcription. We have validated the role of RPS6KB1 in regulating MuV using siRNA knockdown, an inhibitor, and RPS6KB1 knockout cells. We found that MuV grows better in cells lacking RPS6KB1, indicating that it downregulates viral growth. Furthermore, we detected an interaction between the MuV P protein and RPS6KB1, suggesting that RPS6KB1 directly regulates MuV replication and transcription.IMPORTANCE Mumps virus is an important human pathogen. In recent years, MuV has reemerged in the United State, with outbreaks occurring in young adults who have been vaccinated. Our work provides insight into a previously unknown mumps virus-host interaction. RPS6KB1 negatively regulates MuV replication, likely through its interaction with the P protein. Understanding virus-host interactions can lead to novel antiviral drugs and enhanced vaccine production.
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Affiliation(s)
- Kelsey Briggs
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Leyi Wang
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Kaito Nagashima
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - James Zengel
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Ralph A Tripp
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, USA
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4
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Young DF, Andrejeva J, Li X, Inesta-Vaquera F, Dong C, Cowling VH, Goodbourn S, Randall RE. Human IFIT1 Inhibits mRNA Translation of Rubulaviruses but Not Other Members of the Paramyxoviridae Family. J Virol 2016; 90:9446-56. [PMID: 27512068 PMCID: PMC5044818 DOI: 10.1128/jvi.01056-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/03/2016] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED We have previously shown that IFIT1 is primarily responsible for the antiviral action of interferon (IFN) alpha/beta against parainfluenza virus type 5 (PIV5), selectively inhibiting the translation of PIV5 mRNAs. Here we report that while PIV2, PIV5, and mumps virus (MuV) are sensitive to IFIT1, nonrubulavirus members of the paramyxoviridae such as PIV3, Sendai virus (SeV), and canine distemper virus (CDV) are resistant. The IFIT1 sensitivity of PIV5 was not rescued by coinfection with an IFIT1-resistant virus (PIV3), demonstrating that PIV3 does not specifically inhibit the antiviral activity of IFIT1 and that the inhibition of PIV5 mRNAs is regulated by cis-acting elements. We developed an in vitro translation system using purified human IFIT1 to further investigate the mechanism of action of IFIT1. While the translations of PIV2, PIV5, and MuV mRNAs were directly inhibited by IFIT1, the translations of PIV3, SeV, and CDV mRNAs were not. Using purified human mRNA-capping enzymes, we show biochemically that efficient inhibition by IFIT1 is dependent upon a 5' guanosine nucleoside cap (which need not be N7 methylated) and that this sensitivity is partly abrogated by 2'O methylation of the cap 1 ribose. Intriguingly, PIV5 M mRNA, in contrast to NP mRNA, remained sensitive to inhibition by IFIT1 following in vitro 2'O methylation, suggesting that other structural features of mRNAs may influence their sensitivity to IFIT1. Thus, surprisingly, the viral polymerases (which have 2'-O-methyltransferase activity) of rubulaviruses do not protect these viruses from inhibition by IFIT1. Possible biological consequences of this are discussed. IMPORTANCE Paramyxoviruses cause a wide variety of diseases, and yet most of their genes encode structural proteins and proteins involved in their replication cycle. Thus, the amount of genetic information that determines the type of disease that paramyxoviruses cause is relatively small. One factor that will influence disease outcomes is how they interact with innate host cell defenses, including the interferon (IFN) system. Here we show that different paramyxoviruses interact in distinct ways with cells in a preexisting IFN-induced antiviral state. Strikingly, all the rubulaviruses tested were sensitive to the antiviral action of ISG56/IFIT1, while all the other paramyxoviruses tested were resistant. We developed novel in vitro biochemical assays to investigate the mechanism of action of IFIT1, demonstrating that the mRNAs of rubulaviruses can be directly inhibited by IFIT1 and that this is at least partially because their mRNAs are not correctly methylated.
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Affiliation(s)
- D F Young
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - J Andrejeva
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
| | - X Li
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - F Inesta-Vaquera
- School of Life Sciences, Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - C Dong
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - V H Cowling
- School of Life Sciences, Centre for Gene Regulation and Expression, University of Dundee, Dundee, United Kingdom
| | - S Goodbourn
- Institute for Infection and Immunity, St. George's, University of London, London, United Kingdom
| | - R E Randall
- School of Biology, Centre for Biomolecular Sciences, University of St. Andrews, St. Andrews, Fife, United Kingdom
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5
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Recombinant mumps virus as a cancer therapeutic agent. MOLECULAR THERAPY-ONCOLYTICS 2016; 3:16019. [PMID: 27556105 PMCID: PMC4980112 DOI: 10.1038/mto.2016.19] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 12/22/2022]
Abstract
Mumps virus belongs to the family of Paramyxoviridae and has the potential to be an oncolytic agent. Mumps virus Urabe strain had been tested in the clinical setting as a treatment for human cancer four decades ago in Japan. These clinical studies demonstrated that mumps virus could be a promising cancer therapeutic agent that showed significant antitumor activity against various types of cancers. Since oncolytic virotherapy was not in the limelight until the beginning of the 21st century, the interest to pursue mumps virus for cancer treatment slowly faded away. Recent success stories of oncolytic clinical trials prompted us to resurrect the mumps virus and to explore its potential for cancer treatment. We have obtained the Urabe strain of mumps virus from Osaka University, Japan, which was used in the earlier human clinical trials. In this report we describe the development of a reverse genetics system from a major isolate of this Urabe strain mumps virus stock, and the construction and characterization of several recombinant mumps viruses with additional transgenes. We present initial data demonstrating these recombinant mumps viruses have oncolytic activity against tumor cell lines in vitro and some efficacy in preliminary pilot animal tumor models.
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6
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Jin L, Örvell C, Myers R, Rota PA, Nakayama T, Forcic D, Hiebert J, Brown KE. Genomic diversity of mumps virus and global distribution of the 12 genotypes. Rev Med Virol 2014; 25:85-101. [DOI: 10.1002/rmv.1819] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Li Jin
- Virus Reference Department, Reference Microbiology Services; Public Health England; London UK
| | - Claes Örvell
- Division of Clinical Virology; Huddinge University Hospital; Stockholm Sweden
| | - Richard Myers
- Virus Reference Department, Reference Microbiology Services; Public Health England; London UK
| | - Paul A. Rota
- Centers for Disease Control and Prevention; Atlanta USA
| | | | - Dubravko Forcic
- University of Zagreb; Centre for Research and Knowledge Transfer in Biotechnology; Zagreb Croatia
| | - Joanne Hiebert
- National Microbiology Laboratory; Public Health Agency of Canada; Winnipeg Canada
| | - Kevin E. Brown
- Virus Reference Department, Reference Microbiology Services; Public Health England; London UK
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7
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Stewart CE, Randall RE, Adamson CS. Inhibitors of the interferon response enhance virus replication in vitro. PLoS One 2014; 9:e112014. [PMID: 25390891 PMCID: PMC4229124 DOI: 10.1371/journal.pone.0112014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 10/11/2014] [Indexed: 12/24/2022] Open
Abstract
Virus replication efficiency is influenced by two conflicting factors, kinetics of the cellular interferon (IFN) response and induction of an antiviral state versus speed of virus replication and virus-induced inhibition of the IFN response. Disablement of a virus's capacity to circumvent the IFN response enables both basic research and various practical applications. However, such IFN-sensitive viruses can be difficult to grow to high-titer in cells that produce and respond to IFN. The current default option for growing IFN-sensitive viruses is restricted to a limited selection of cell-lines (e.g. Vero cells) that have lost their ability to produce IFN. This study demonstrates that supplementing tissue-culture medium with an IFN inhibitor provides a simple, effective and flexible approach to increase the growth of IFN-sensitive viruses in a cell-line of choice. We report that IFN inhibitors targeting components of the IFN response (TBK1, IKK2, JAK1) significantly increased virus replication. More specifically, the JAK1/2 inhibitor Ruxolitinib enhances the growth of viruses that are sensitive to IFN due to (i) loss of function of the viral IFN antagonist (due to mutation or species-specific constraints) or (ii) mutations/host cell constraints that slow virus spread such that it can be controlled by the IFN response. This was demonstrated for a variety of viruses, including, viruses with disabled IFN antagonists that represent live-attenuated vaccine candidates (Respiratory Syncytial Virus (RSV), Influenza Virus), traditionally attenuated vaccine strains (Measles, Mumps) and a slow-growing wild-type virus (RSV). In conclusion, supplementing tissue culture-medium with an IFN inhibitor to increase the growth of IFN-sensitive viruses in a cell-line of choice represents an approach, which is broadly applicable to research investigating the importance of the IFN response in controlling virus infections and has utility in a number of practical applications including vaccine and oncolytic virus production, virus diagnostics and techniques to isolate newly emerging viruses.
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Affiliation(s)
- Claire E. Stewart
- School of Biology, University of St Andrews, Fife, Scotland, United Kingdom
| | - Richard E. Randall
- School of Biology, University of St Andrews, Fife, Scotland, United Kingdom
| | - Catherine S. Adamson
- School of Biology, University of St Andrews, Fife, Scotland, United Kingdom
- * E-mail:
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8
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Li S, Tong J, Rahman MM, Shepherd TG, McFadden G. Oncolytic virotherapy for ovarian cancer. Oncolytic Virother 2012; 1:1-21. [PMID: 25977900 DOI: 10.2147/ov.s31626] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In the past two decades, more than 20 viruses with selective tropism for tumor cells have been developed as oncolytic viruses (OVs) for treatments of a variety of malignancies. Of these viruses, eleven have been tested in human ovarian cancer models in preclinical studies. So far, nine phase I or II clinical trials have been conducted or initiated using four different types of OVs in patients with recurrent ovarian cancers. In this article, we summarize the different OVs that are being assessed as therapeutics for ovarian cancer. We also present an overview of recent advances in identification of key genetic or immune-response pathways involved in tumorigenesis of ovarian cancer, which provides a better understanding of the tumor specificities and oncolytic properties of OVs. In addition, we discuss how next-generation OVs could be genetically modified or integrated into multimodality regimens to improve clinical outcomes based on recent advances in ovarian cancer biology.
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Affiliation(s)
- Shoudong Li
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Jessica Tong
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada ; Translational Ovarian Cancer Research Program, London Health Sciences Centre, London, Ontario, Canada
| | - Masmudur M Rahman
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Trevor G Shepherd
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada ; Translational Ovarian Cancer Research Program, London Health Sciences Centre, London, Ontario, Canada
| | - Grant McFadden
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
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9
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Regulatory, biosafety and safety challenges for novel cells as substrates for human vaccines. Vaccine 2012; 30:2715-27. [DOI: 10.1016/j.vaccine.2012.02.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/31/2012] [Accepted: 02/05/2012] [Indexed: 12/24/2022]
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10
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Killip MJ, Young DF, Precious BL, Goodbourn S, Randall RE. Activation of the beta interferon promoter by paramyxoviruses in the absence of virus protein synthesis. J Gen Virol 2011; 93:299-307. [PMID: 22049094 PMCID: PMC3352343 DOI: 10.1099/vir.0.037531-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Conflicting reports exist regarding the requirement for virus replication in interferon (IFN) induction by paramyxoviruses. Our previous work has demonstrated that pathogen-associated molecular patterns capable of activating the IFN-induction cascade are not normally generated during virus replication, but are associated instead with the presence of defective interfering (DI) viruses. We demonstrate here that DIs of paramyxoviruses, including parainfluenza virus 5, mumps virus and Sendai virus, can activate the IFN-induction cascade and the IFN-β promoter in the absence of virus protein synthesis. As virus protein synthesis is an absolute requirement for paramyxovirus genome replication, our results indicate that these DI viruses do not require replication to activate the IFN-induction cascade.
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Affiliation(s)
- M J Killip
- School of Biology, Centre for Biomolecular Sciences, BMS Building, North Haugh, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - D F Young
- School of Biology, Centre for Biomolecular Sciences, BMS Building, North Haugh, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - B L Precious
- School of Biology, Centre for Biomolecular Sciences, BMS Building, North Haugh, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - S Goodbourn
- Division of Basic Medical Sciences, St George's, University of London, London SW17 0RE, UK
| | - R E Randall
- School of Biology, Centre for Biomolecular Sciences, BMS Building, North Haugh, University of St Andrews, St Andrews, Fife KY16 9ST, UK
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11
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Seitz C, Isken B, Heynisch B, Rettkowski M, Frensing T, Reichl U. Trypsin promotes efficient influenza vaccine production in MDCK cells by interfering with the antiviral host response. Appl Microbiol Biotechnol 2011; 93:601-11. [PMID: 21915610 DOI: 10.1007/s00253-011-3569-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/12/2011] [Accepted: 08/29/2011] [Indexed: 12/24/2022]
Abstract
Trypsin is commonly used in Madin-Darby canine kidney (MDCK) cell culture-based influenza vaccine production to facilitate virus infection by proteolytic activation of viral haemagglutinin, which enables multi-cycle replication. In this study, we were able to demonstrate that trypsin also interferes with pathogen defence mechanisms of host cells. In particular, a trypsin concentration of 5 BAEE U/mL (4.5 μg/mL porcine trypsin) used in vaccine manufacturing strongly inhibited interferon (IFN) signalling by proteolytic degradation of secreted IFN. Consequently, absence of trypsin during infection resulted in a considerably stronger induction of IFN signalling and apoptosis, which significantly reduced virus yields. Under this condition, multi-cycle virus replication in MDCK cells was not prevented but clearly delayed. Therefore, incomplete infection can be ruled out as the reason for the lower virus titres. However, suppression of IFN signalling by overexpression of viral IFN antagonists (influenza virus PR8-NS1, rabies virus phosphoprotein) partially rescued virus titres in the absence of trypsin. In addition, virus yields could be almost restored by using the influenza strain A/WSN/33 in combination with fetal calf serum (FCS). For this strain, FCS enabled trypsin-independent fast propagation of virus infection, probably outrunning cellular defence mechanisms and apoptosis induction in the absence of trypsin. Overall, addition of trypsin provided optimal conditions for high yield vaccine production in MDCK cells by two means. On the one hand, proteolytic degradation of IFN keeps cellular defence at a low level. On the other hand, enhanced virus spreading enables viruses to replicate before the cellular response becomes fully activated.
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Affiliation(s)
- Claudius Seitz
- Bioprocess Engineering, Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106, Magdeburg, Germany
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12
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Chen S, Short JAL, Young DF, Killip MJ, Schneider M, Goodbourn S, Randall RE. Heterocellular induction of interferon by negative-sense RNA viruses. Virology 2010; 407:247-55. [PMID: 20833406 PMCID: PMC2963793 DOI: 10.1016/j.virol.2010.08.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 08/11/2010] [Indexed: 12/24/2022]
Abstract
The infection of cells by RNA viruses is associated with the recognition of virus PAMPs (pathogen-associated molecular patterns) and the production of type I interferon (IFN). To counter this, most, if not all, RNA viruses encode antagonists of the IFN system. Here we present data on the dynamics of IFN production and response during developing infections by paramyxoviruses, influenza A virus and bunyamwera virus. We show that only a limited number of infected cells are responsible for the production of IFN, and that this heterocellular production is a feature of the infecting virus as opposed to an intrinsic property of the cells.
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Affiliation(s)
- S Chen
- School of Biology, Centre for Biomolecular Sciences, BMS Building, North Haugh, University of St. Andrews, St. Andrews, Fife, KY16 9ST, UK
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