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Heinzer D, Avar M, Pfammatter M, Moos R, Schwarz P, Buhmann MT, Kuhn B, Mauerhofer S, Rosenberg U, Aguzzi A, Hornemann S. Advancing surgical instrument safety: A screen of oxidative and alkaline prion decontaminants using real-time quaking-induced conversion with prion-coated steel beads as surgical instrument mimetic. PLoS One 2024; 19:e0304603. [PMID: 38870196 PMCID: PMC11175539 DOI: 10.1371/journal.pone.0304603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 05/14/2024] [Indexed: 06/15/2024] Open
Abstract
Iatrogenic transmission of prions, the infectious agents of fatal Creutzfeldt-Jakob disease, through inefficiently decontaminated medical instruments remains a critical issue. Harsh chemical treatments are effective, but not suited for routine reprocessing of reusable surgical instruments in medical cleaning and disinfection processes due to material incompatibilities. The identification of mild detergents with activity against prions is therefore of high interest but laborious due to the low throughput of traditional assays measuring prion infectivity. Here, we report the establishment of TESSA (sTainlESs steel-bead Seed Amplification assay), a modified real-time quaking induced cyclic amplification (RT-QuIC) assay that explores the propagation activity of prions with stainless steel beads. TESSA was applied for the screening of about 70 different commercially available and novel formulations and conditions for their prion inactivation efficacy. One hypochlorite-based formulation, two commercially available alkaline formulations and a manual alkaline pre-cleaner were found to be highly effective in inactivating prions under conditions simulating automated washer-disinfector cleaning processes. The efficacy of these formulations was confirmed in vivo in a murine prion infectivity bioassay, yielding a reduction of the prion titer for bead surface adsorbed prions below detectability. Our data suggest that TESSA represents an effective method for a rapid screening of prion-inactivating detergents, and that alkaline and oxidative formulations are promising in reducing the risk of potential iatrogenic prion transmission through insufficiently decontaminated instrument surfaces.
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Affiliation(s)
- Daniel Heinzer
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Merve Avar
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Rita Moos
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Petra Schwarz
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | | | | | | | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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2
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Burgener K, Lichtenberg SS, Walsh DP, Inzalaco HN, Lomax A, Pedersen JA. Prion Seeding Activity in Plant Tissues Detected by RT-QuIC. Pathogens 2024; 13:452. [PMID: 38921750 PMCID: PMC11206635 DOI: 10.3390/pathogens13060452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/09/2024] [Accepted: 05/24/2024] [Indexed: 06/27/2024] Open
Abstract
Prion diseases such as scrapie, bovine spongiform encephalopathy (BSE), and chronic wasting disease (CWD) affect domesticated and wild herbivorous mammals. Animals afflicted with CWD, the transmissible spongiform encephalopathy of cervids (deer, elk, and moose), shed prions into the environment, where they may persist and remain infectious for years. These environmental prions may remain in soil, be transported in surface waters, or assimilated into plants. Environmental sampling is an emerging area of TSE research and can provide more information about prion fate and transport once shed by infected animals. In this study, we have developed the first published method for the extraction and detection of prions in plant tissue using the real-time quaking-induced conversion (RT-QuIC) assay. Incubation with a zwitterionic surfactant followed by precipitation with sodium phosphotungstate concentrates the prions within samples and allows for sensitive detection of prion seeding activity. Using this protocol, we demonstrate that prions can be detected within plant tissues and on plant surfaces using the RT-QuIC assay.
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Affiliation(s)
- Kate Burgener
- Molecular and Environmental Toxicology Program, University of Wisconsin-Madison, Madison, WI 53706, USA; (K.B.)
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Stuart Siegfried Lichtenberg
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108, USA
- Minnesota Center for Prion Research and Outreach, University of Minnesota, St. Paul, MN 55108, USA
| | - Daniel P. Walsh
- U.S. Geological Survey, Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT 59812, USA
| | - Heather N. Inzalaco
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Aaron Lomax
- Department of Soil Science, University of Wisconsin-Madison, Madison, WI 53706, USA;
- Varizymes, Middleton, WI 53562, USA
| | - Joel A. Pedersen
- Molecular and Environmental Toxicology Program, University of Wisconsin-Madison, Madison, WI 53706, USA; (K.B.)
- Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Soil Science, University of Wisconsin-Madison, Madison, WI 53706, USA;
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3
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Secker TJ, Hervé RC, Keevil CW. Sensitive microscopic quantification of surface-bound prion infectivity for the assessment of surgical instrument decontamination procedures. J Hosp Infect 2023; 132:116-124. [PMID: 36209927 DOI: 10.1016/j.jhin.2022.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND Pathogenic prions (PrPSc) are amyloid-rich hydrophobic proteins which bind avidly to surgical surfaces and represent some of the most difficult targets during the reprocessing of reusable surgical instruments. In-vitro methods to amplify and detect the presence of otherwise undetectable prion contamination are available, but they do not measure associated infectivity. Most of these methods rely on the use of proteinase K, however this can lead to the loss of a substantial portion of PrPSc, potentially producing false negatives. AIM To develop a sensitive in-situ method without proteinase treatment for the dynamic quantification of amyloid accumulation in N2a #58 cells following 22L-prion infection from infected tissues and spiked stainless-steel surfaces. METHODS We spiked cultures of N2a #58 cells with the 22L prion strain in solution or dried on stainless-steel wires and directly measured the accumulation of prion amyloid aggregates over several passages using highly sensitive fluorescence microscopy. FINDINGS We demonstrated a 10-log dynamic range using our method to test residual prion infectivity, that was validated to show variable decontamination efficacy against prions from commercially available cleaning chemistries. CONCLUSIONS The new cell-based infectivity method presented here avoids partial or possibly total proteinase K digestion of PrPSc in samples for greater sensitivity, in addition to low cost, no ethical concerns, and adaptability to detect different prion strains. This method can be used to test cleaning chemistries' efficacy with greater sensitivity than measuring total residual proteins, which may not correlate with residual prion infectivity.
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Affiliation(s)
- T J Secker
- Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK
| | - R C Hervé
- Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK.
| | - C W Keevil
- Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK
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4
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Ren YS, Li HL, Piao XH, Yang ZY, Wang SM, Ge YW. Drug affinity responsive target stability (DARTS) accelerated small molecules target discovery: Principles and application. Biochem Pharmacol 2021; 194:114798. [PMID: 34678227 DOI: 10.1016/j.bcp.2021.114798] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 12/19/2022]
Abstract
Drug affinity responsive target stability (DARTS) is a novel target discovery approach and is particularly adept at screening small molecule (SM) targets without requiring any structural modifications. The DARTS method is capable of revealing drug-target interactions from cells or tissues by tracking changes in the stability of proteins acting as receptors of bioactive SMs. Due to its simple operation and high efficiency, the DARTS method has been applied to uncover the drug-action mechanism. This review summarized analytical principles, protocols, validation approaches, applications, and challenges involved in the DARTS method. Due to the innate advantages of the DARTS method, it is expected to be a powerful tool to accelerate SM target discovery, especially for bioactive natural products with unknown mechanisms.
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Affiliation(s)
- Ying-Shan Ren
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, Guangdong Pharmaceutical University, Guangzhou 510006, China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Hui-Lin Li
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, Guangdong Pharmaceutical University, Guangzhou 510006, China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Xiu-Hong Piao
- Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, Guangdong Pharmaceutical University, Guangzhou 510006, China; School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.
| | - Zhi-You Yang
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China
| | - Shu-Mei Wang
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, Guangdong Pharmaceutical University, Guangzhou 510006, China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, Guangdong Pharmaceutical University, Guangzhou 510006, China.
| | - Yue-Wei Ge
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, Guangdong Pharmaceutical University, Guangzhou 510006, China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, Guangdong Pharmaceutical University, Guangzhou 510006, China.
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5
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Abstract
Prions are infectious agents which cause rapidly lethal neurodegenerative diseases in humans and animals following long, clinically silent incubation periods. They are composed of multichain assemblies of misfolded cellular prion protein. While it has long been assumed that prions are themselves neurotoxic, recent development of methods to obtain exceptionally pure prions from mouse brain with maintained strain characteristics, and in which defined structures-paired rod-like double helical fibers-can be definitively correlated with infectivity, allowed a direct test of this assertion. Here we report that while brain homogenates from symptomatic prion-infected mice are highly toxic to cultured neurons, exceptionally pure intact high-titer infectious prions are not directly neurotoxic. We further show that treatment of brain homogenates from prion-infected mice with sodium lauroylsarcosine destroys toxicity without diminishing infectivity. This is consistent with models in which prion propagation and toxicity can be mechanistically uncoupled.
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6
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Esmaili M, Tancowny BP, Wang X, Moses A, Cortez LM, Sim VL, Wille H, Overduin M. Native nanodiscs formed by styrene maleic acid copolymer derivatives help recover infectious prion multimers bound to brain-derived lipids. J Biol Chem 2020; 295:8460-8469. [PMID: 32358064 DOI: 10.1074/jbc.ra119.012348] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/14/2020] [Indexed: 11/06/2022] Open
Abstract
Prions are lipidated proteins that interact with endogenous lipids and metal ions. They also assemble into multimers and propagate into the infectious scrapie form known as PrPSc The high-resolution structure of the infectious PrPSc state remains unknown, and its analysis largely relies on detergent-based preparations devoid of endogenous ligands. Here we designed polymers that allow isolation of endogenous membrane:protein assemblies in native nanodiscs without exposure to conventional detergents that destabilize protein structures and induce fibrillization. A set of styrene-maleic acid (SMA) polymers including a methylamine derivative facilitated gentle release of the infectious complexes for resolution of multimers, and a thiol-containing version promoted crystallization. Polymer extraction from brain homogenates from Syrian hamsters infected with Hyper prions and WT mice infected with Rocky Mountain Laboratories prions yielded infectious prion nanoparticles including oligomers and microfilaments bound to lipid vesicles. Lipid analysis revealed the brain phospholipids that associate with prion protofilaments, as well as those that are specifically enriched in prion assemblies captured by the methylamine-modified copolymer. A comparison of the infectivity of PrPSc attached to SMA lipid particles in mice and hamsters indicated that these amphipathic polymers offer a valuable tool for high-yield production of intact, detergent-free prions that retain in vivo activity. This native prion isolation method provides an avenue for producing relevant prion:lipid targets and potentially other proteins that form multimeric assemblies and fibrils on membranes.
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Affiliation(s)
- Mansoore Esmaili
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Brian P Tancowny
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.,Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Xiongyao Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.,Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Audric Moses
- Lipidomics Core Facility, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Leonardo M Cortez
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Division of Neurology, Department of Medicine, Centre for Prions and Protein Folding Diseases, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Valerie L Sim
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Division of Neurology, Department of Medicine, Centre for Prions and Protein Folding Diseases, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Holger Wille
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada .,Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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7
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Terry C, Wadsworth JDF. Recent Advances in Understanding Mammalian Prion Structure: A Mini Review. Front Mol Neurosci 2019; 12:169. [PMID: 31338021 PMCID: PMC6629788 DOI: 10.3389/fnmol.2019.00169] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 06/17/2019] [Indexed: 12/15/2022] Open
Abstract
Prions are lethal pathogens, which cause fatal neurodegenerative diseases in mammals. They are unique infectious agents and are composed of self-propagating multi-chain assemblies of misfolded host-encoded prion protein (PrP). Understanding prion structure is fundamental to understanding prion disease pathogenesis however to date, the high-resolution structure of authentic ex vivo infectious prions remains unknown. Advances in determining prion structure have been severely impeded by the difficulty in recovering relatively homogeneous prion particles from infected brain and definitively associating infectivity with the PrP assembly state. Recently, however, images of highly infectious ex vivo PrP rods that produce prion-strain specific disease phenotypes in mice have been obtained using cryo-electron microscopy and atomic force microscopy. These images have provided the most detailed description of ex vivo mammalian prions reported to date and have established that prions isolated from multiple strains have a common hierarchical structure. Misfolded PrP is assembled into 20 nm wide rods containing two fibers, each with double helical repeating substructure, separated by a characteristic central gap 8–10 nm in width. Irregularly structured material with adhesive properties distinct to that of the fibers is present within the central gap of the rod. Prions are clearly distinguishable from non-infectious recombinant PrP fibrils generated in vitro and from all other propagating protein structures so far described in other neurodegenerative diseases. The basic architecture of mammalian prions appears to be exceptional and fundamental to their lethal pathogenicity.
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Affiliation(s)
- Cassandra Terry
- Molecular Systems for Health Research Group, School of Human Sciences, London Metropolitan University, London, United Kingdom
| | - Jonathan D F Wadsworth
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, University College London, London, United Kingdom
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8
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Thapa S, Abdulrahman B, Abdelaziz DH, Lu L, Ben Aissa M, Schatzl HM. Overexpression of quality control proteins reduces prion conversion in prion-infected cells. J Biol Chem 2018; 293:16069-16082. [PMID: 30154245 PMCID: PMC6187620 DOI: 10.1074/jbc.ra118.002754] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/09/2018] [Indexed: 11/06/2022] Open
Abstract
Prion diseases are fatal infectious neurodegenerative disorders in humans and other animals and are caused by misfolding of the cellular prion protein (PrPC) into the pathological isoform PrPSc. These diseases have the potential to transmit within or between species, including zoonotic transmission to humans. Elucidating the molecular and cellular mechanisms underlying prion propagation and transmission is therefore critical for developing molecular strategies for disease intervention. We have shown previously that impaired quality control mechanisms directly influence prion propagation. In this study, we manipulated cellular quality control pathways in vitro by stably and transiently overexpressing selected quality control folding (ERp57) and cargo (VIP36) proteins and investigated the effects of this overexpression on prion propagation. We found that ERp57 or VIP36 overexpression in persistently prion-infected neuroblastoma cells significantly reduces the amount of PrPSc in immunoblots and prion-seeding activity in the real-time quaking-induced conversion (RT-QuIC) assay. Using different cell lines infected with various prion strains confirmed that this effect is not cell type– or prion strain–specific. Moreover, de novo prion infection revealed that the overexpression significantly reduced newly formed PrPSc in acutely infected cells. ERp57-overexpressing cells significantly overcame endoplasmic reticulum stress, as revealed by expression of lower levels of the stress markers BiP and CHOP, accompanied by a decrease in PrP aggregates. Furthermore, application of ERp57-expressing lentiviruses prolonged the survival of prion-infected mice. Taken together, improved cellular quality control via ERp57 or VIP36 overexpression impairs prion propagation and could be utilized as a potential therapeutic strategy.
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Affiliation(s)
- Simrika Thapa
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada
| | - Basant Abdulrahman
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Helwan University, 11795 Cairo, Egypt, and
| | - Dalia H Abdelaziz
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Helwan University, 11795 Cairo, Egypt, and
| | - Li Lu
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada
| | - Manel Ben Aissa
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada
| | - Hermann M Schatzl
- From the Calgary Prion Research Unit, University of Calgary, Calgary, Alberta T2N 4Z6, Canada, .,the Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada.,the Departments of Veterinary Sciences and of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071
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9
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Sarell CJ, Quarterman E, Yip DCM, Terry C, Nicoll AJ, Wadsworth JDF, Farrow MA, Walsh DM, Collinge J. Soluble Aβ aggregates can inhibit prion propagation. Open Biol 2018; 7:rsob.170158. [PMID: 29142106 PMCID: PMC5717343 DOI: 10.1098/rsob.170158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022] Open
Abstract
Mammalian prions cause lethal neurodegenerative diseases such as Creutzfeldt–Jakob disease (CJD) and consist of multi-chain assemblies of misfolded cellular prion protein (PrPC). Ligands that bind to PrPC can inhibit prion propagation and neurotoxicity. Extensive prior work established that certain soluble assemblies of the Alzheimer's disease (AD)-associated amyloid β-protein (Aβ) can tightly bind to PrPC, and that this interaction may be relevant to their toxicity in AD. Here, we investigated whether such soluble Aβ assemblies might, conversely, have an inhibitory effect on prion propagation. Using cellular models of prion infection and propagation and distinct Aβ preparations, we found that the form of Aβ assemblies which most avidly bound to PrP in vitro also inhibited prion infection and propagation. By contrast, forms of Aβ which exhibit little or no binding to PrP were unable to attenuate prion propagation. These data suggest that soluble aggregates of Aβ can compete with prions for binding to PrPC and emphasize the bidirectional nature of the interplay between Aβ and PrPC in Alzheimer's and prion diseases. Such inhibitory effects of Aβ on prion propagation may contribute to the apparent fall-off in the incidence of sporadic CJD at advanced age where cerebral Aβ deposition is common.
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Affiliation(s)
- Claire J Sarell
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Emma Quarterman
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Daniel C-M Yip
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Cassandra Terry
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Andrew J Nicoll
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jonathan D F Wadsworth
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Mark A Farrow
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Dominic M Walsh
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK .,Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - John Collinge
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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10
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PrP Knockout Cells Expressing Transmembrane PrP Resist Prion Infection. J Virol 2017; 91:JVI.01686-16. [PMID: 27847358 DOI: 10.1128/jvi.01686-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/01/2016] [Indexed: 11/20/2022] Open
Abstract
Glycosylphosphatidylinositol (GPI) anchoring of the prion protein (PrPC) influences PrPC misfolding into the disease-associated isoform, PrPres, as well as prion propagation and infectivity. GPI proteins are found in cholesterol- and sphingolipid-rich membrane regions called rafts. Exchanging the GPI anchor for a nonraft transmembrane sequence redirects PrPC away from rafts. Previous studies showed that nonraft transmembrane PrPC variants resist conversion to PrPres when transfected into scrapie-infected N2a neuroblastoma cells, likely due to segregation of transmembrane PrPC and GPI-anchored PrPres in distinct membrane environments. Thus, it remained unclear whether transmembrane PrPC might convert to PrPres if seeded by an exogenous source of PrPres not associated with host cell rafts and without the potential influence of endogenous expression of GPI-anchored PrPC To further explore these questions, constructs containing either a C-terminal wild-type GPI anchor signal sequence or a nonraft transmembrane sequence containing a flexible linker were expressed in a cell line derived from PrP knockout hippocampal neurons, NpL2. NpL2 cells have physiological similarities to primary neurons, representing a novel and advantageous model for studying transmissible spongiform encephalopathy (TSE) infection. Cells were infected with inocula from multiple prion strains and in different biochemical states (i.e., membrane bound as in brain microsomes from wild-type mice or purified GPI-anchorless amyloid fibrils). Only GPI-anchored PrPC supported persistent PrPres propagation. Our data provide strong evidence that in cell culture GPI anchor-directed membrane association of PrPC is required for persistent PrPres propagation, implicating raft microdomains as a location for conversion. IMPORTANCE Mechanisms of prion propagation, and what makes them transmissible, are poorly understood. Glycosylphosphatidylinositol (GPI) membrane anchoring of the prion protein (PrPC) directs it to specific regions of cell membranes called rafts. In order to test the importance of the raft environment on prion propagation, we developed a novel model for prion infection where cells expressing either GPI-anchored PrPC or transmembrane-anchored PrPC, which partitions it to a different location, were treated with infectious, misfolded forms of the prion protein, PrPres We show that only GPI-anchored PrPC was able to convert to PrPres and able to serially propagate. The results strongly suggest that GPI anchoring and the localization of PrPC to rafts are crucial to the ability of PrPC to propagate as a prion.
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11
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The Structure of Mammalian Prions and Their Aggregates. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 329:277-301. [PMID: 28109330 DOI: 10.1016/bs.ircmb.2016.08.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Prion diseases, such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy in cattle, chronic wasting disease in cervids (i.e., deer, elk, moose, and reindeer), and sheep scrapie, are caused by the misfolding of the cellular prion protein (PrPC) into a disease-causing conformer (PrPSc). PrPC is a normal, GPI-anchored protein that is expressed on the surface of neurons and other cell types. The structure of PrPC is well understood, based on studies of recombinant PrP, which closely mimics the structure of native PrPC. In contrast, PrPSc is prone to aggregate into a variety of quaternary structures, such as oligomers, amorphous aggregates, and amyloid fibrils. The propensity of PrPSc to assemble into these diverse forms of aggregates is also responsible for our limited knowledge about its structure. Then again, the repeating nature of certain regular PrPSc aggregates has allowed (lower resolution) insights into the structure of the infectious conformer, establishing a four-rung β-solenoid structure as a key element of its architecture.
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12
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Miyazawa K, Okada H, Masujin K, Iwamaru Y, Yokoyama T. Infectivity-associated PrP(Sc) and disease duration-associated PrP(Sc) of mouse BSE prions. Prion 2016; 9:394-403. [PMID: 26555211 PMCID: PMC4964868 DOI: 10.1080/19336896.2015.1111507] [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] [Indexed: 11/06/2022] Open
Abstract
Disease-related prion protein (PrPSc), which is a structural isoform of the host-encoded cellular prion protein, is thought to be a causative agent of transmissible spongiform encephalopathies. However, the specific role of PrPSc in prion pathogenesis and its relationship to infectivity remain controversial. A time-course study of prion-affected mice was conducted, which showed that the prion infectivity was not simply proportional to the amount of PrPSc in the brain. Centrifugation (20,000 ×g) of the brain homogenate showed that most of the PrPSc was precipitated into the pellet, and the supernatant contained only a slight amount of PrPSc. Interestingly, mice inoculated with the obtained supernatant showed incubation periods that were approximately 15 d longer than those of mice inoculated with the crude homogenate even though both inocula contained almost the same infectivity. Our results suggest that a small population of fine PrPSc may be responsible for prion infectivity and that large, aggregated PrPSc may contribute to determining prion disease duration.
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Affiliation(s)
- Kohtaro Miyazawa
- a Influenza and Prion Disease Research Center; National Institute of Animal Health ; Tsukuba , Ibaraki , Japan
| | - Hiroyuki Okada
- a Influenza and Prion Disease Research Center; National Institute of Animal Health ; Tsukuba , Ibaraki , Japan
| | - Kentaro Masujin
- a Influenza and Prion Disease Research Center; National Institute of Animal Health ; Tsukuba , Ibaraki , Japan
| | - Yoshifumi Iwamaru
- a Influenza and Prion Disease Research Center; National Institute of Animal Health ; Tsukuba , Ibaraki , Japan
| | - Takashi Yokoyama
- a Influenza and Prion Disease Research Center; National Institute of Animal Health ; Tsukuba , Ibaraki , Japan
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13
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Schmidt C, Fizet J, Properzi F, Batchelor M, Sandberg MK, Edgeworth JA, Afran L, Ho S, Badhan A, Klier S, Linehan JM, Brandner S, Hosszu LLP, Tattum MH, Jat P, Clarke AR, Klöhn PC, Wadsworth JDF, Jackson GS, Collinge J. A systematic investigation of production of synthetic prions from recombinant prion protein. Open Biol 2016; 5:150165. [PMID: 26631378 PMCID: PMC4703057 DOI: 10.1098/rsob.150165] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
According to the protein-only hypothesis, infectious mammalian prions, which exist as distinct strains with discrete biological properties, consist of multichain assemblies of misfolded cellular prion protein (PrP). A critical test would be to produce prion strains synthetically from defined components. Crucially, high-titre ‘synthetic' prions could then be used to determine the structural basis of infectivity and strain diversity at the atomic level. While there have been multiple reports of production of prions from bacterially expressed recombinant PrP using various methods, systematic production of high-titre material in a form suitable for structural analysis remains a key goal. Here, we report a novel high-throughput strategy for exploring a matrix of conditions, additives and potential cofactors that might generate high-titre prions from recombinant mouse PrP, with screening for infectivity using a sensitive automated cell-based bioassay. Overall, approximately 20 000 unique conditions were examined. While some resulted in apparently infected cell cultures, this was transient and not reproducible. We also adapted published methods that reported production of synthetic prions from recombinant hamster PrP, but again did not find evidence of significant infectious titre when using recombinant mouse PrP as substrate. Collectively, our findings are consistent with the formation of prion infectivity from recombinant mouse PrP being a rare stochastic event and we conclude that systematic generation of prions from recombinant PrP may only become possible once the detailed structure of authentic ex vivo prions is solved.
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Affiliation(s)
- Christian Schmidt
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jeremie Fizet
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Francesca Properzi
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Mark Batchelor
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Malin K Sandberg
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Julie A Edgeworth
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Louise Afran
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Sammy Ho
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Anjna Badhan
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Steffi Klier
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jacqueline M Linehan
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Sebastian Brandner
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Laszlo L P Hosszu
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - M Howard Tattum
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Parmjit Jat
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Anthony R Clarke
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Peter C Klöhn
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jonathan D F Wadsworth
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Graham S Jackson
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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14
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A Neuronal Culture System to Detect Prion Synaptotoxicity. PLoS Pathog 2016; 12:e1005623. [PMID: 27227882 PMCID: PMC4881977 DOI: 10.1371/journal.ppat.1005623] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/19/2016] [Indexed: 12/02/2022] Open
Abstract
Synaptic pathology is an early feature of prion as well as other neurodegenerative diseases. Although the self-templating process by which prions propagate is well established, the mechanisms by which prions cause synaptotoxicity are poorly understood, due largely to the absence of experimentally tractable cell culture models. Here, we report that exposure of cultured hippocampal neurons to PrPSc, the infectious isoform of the prion protein, results in rapid retraction of dendritic spines. This effect is entirely dependent on expression of the cellular prion protein, PrPC, by target neurons, and on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic loss. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents. Prion diseases are fatal neurodegenerative disorders that cause memory loss, impaired coordination, and abnormal movements. The molecular culprit in prion diseases is PrPSc, an infectious isoform of a host-encoded glycoprotein (PrPC) that can propagate itself by a self-templating mechanism. Whether PrPSc itself is toxic to neurons, and if so, the cellular mechanisms by which it produces neuronal pathology are largely unknown, in part because of the absence of suitable cell culture models. We describe here a hippocampal neuronal cultural system to detect the toxic effect of PrPSc on dendritic spines, which are postsynaptic elements responsible for excitatory synaptic transmission, and which are implicated in learning, memory, and the earliest stages of neurodegenerative diseases. We found that purified, exogenously applied PrPSc causes acute retraction of dendritic spines, an effect that is entirely dependent on expression of PrPC by target neurons, and on the on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic retraction. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents.
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15
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Terry C, Wenborn A, Gros N, Sells J, Joiner S, Hosszu LLP, Tattum MH, Panico S, Clare DK, Collinge J, Saibil HR, Wadsworth JDF. Ex vivo mammalian prions are formed of paired double helical prion protein fibrils. Open Biol 2016; 6:rsob.160035. [PMID: 27249641 PMCID: PMC4892434 DOI: 10.1098/rsob.160035] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/13/2016] [Indexed: 12/20/2022] Open
Abstract
Mammalian prions are hypothesized to be fibrillar or amyloid forms of prion protein (PrP), but structures observed to date have not been definitively correlated with infectivity and the three-dimensional structure of infectious prions has remained obscure. Recently, we developed novel methods to obtain exceptionally pure preparations of prions from mouse brain and showed that pathogenic PrP in these high-titre preparations is assembled into rod-like assemblies. Here, we have used precise cell culture-based prion infectivity assays to define the physical relationship between the PrP rods and prion infectivity and have used electron tomography to define their architecture. We show that infectious PrP rods isolated from multiple prion strains have a common hierarchical assembly comprising twisted pairs of short fibres with repeating substructure. The architecture of the PrP rods provides a new structural basis for understanding prion infectivity and can explain the inability to systematically generate high-titre synthetic prions from recombinant PrP.
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Affiliation(s)
- Cassandra Terry
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Adam Wenborn
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Nathalie Gros
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jessica Sells
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Susan Joiner
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Laszlo L P Hosszu
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - M Howard Tattum
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Silvia Panico
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
| | - Daniel K Clare
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Helen R Saibil
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
| | - Jonathan D F Wadsworth
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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16
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Kang SG, Kim C, Cortez LM, Carmen Garza M, Yang J, Wille H, Sim VL, Westaway D, McKenzie D, Aiken J. Toll-like receptor-mediated immune response inhibits prion propagation. Glia 2016; 64:937-51. [PMID: 26880394 DOI: 10.1002/glia.22973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 02/03/2023]
Abstract
Prion diseases are progressive neurodegenerative disorders affecting humans and various mammals. The prominent neuropathological change in prion diseases is neuroinflammation characterized by activation of neuroglia surrounding prion deposition. The cause and effect of this cellular response, however, is unclear. We investigated innate immune defenses against prion infection using primary mixed neuronal and glial cultures. Conditional prion propagation occurred in glial cultures depending on their immune status. Preconditioning of the cells with the toll-like receptor (TLR) ligand, lipopolysaccharide, resulted in a reduction in prion propagation, whereas suppression of the immune responses with the synthetic glucocorticoid, dexamethasone, increased prion propagation. In response to recombinant prion fibrils, glial cells up-regulated TLRs (TLR1 and TLR2) expression and secreted cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6, granulocyte-macrophage colony-stimulating factor, and interferon-β). Preconditioning of neuronal and glial cultures with recombinant prion fibrils inhibited prion replication and altered microglial and astrocytic populations. Our results provide evidence that, in early stages of prion infection, glial cells respond to prion infection through TLR-mediated innate immunity.
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Affiliation(s)
- Sang-Gyun Kang
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Chiye Kim
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Leonardo M Cortez
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - María Carmen Garza
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Jing Yang
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
| | - Holger Wille
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Valerie L Sim
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada.,Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - David Westaway
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada.,Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Debbie McKenzie
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Judd Aiken
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada.,Department of Agricultural, Food, and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
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17
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Wenborn A, Terry C, Gros N, Joiner S, D'Castro L, Panico S, Sells J, Cronier S, Linehan JM, Brandner S, Saibil HR, Collinge J, Wadsworth JDF. A novel and rapid method for obtaining high titre intact prion strains from mammalian brain. Sci Rep 2015; 5:10062. [PMID: 25950908 PMCID: PMC4423448 DOI: 10.1038/srep10062] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/26/2015] [Indexed: 02/02/2023] Open
Abstract
Mammalian prions exist as multiple strains which produce characteristic and highly reproducible phenotypes in defined hosts. How this strain diversity is encoded by a protein-only agent remains one of the most interesting and challenging questions in biology with wide relevance to understanding other diseases involving the aggregation or polymerisation of misfolded host proteins. Progress in understanding mammalian prion strains has however been severely limited by the complexity and variability of the methods used for their isolation from infected tissue and no high resolution structures have yet been reported. Using high-throughput cell-based prion bioassay to re-examine prion purification from first principles we now report the isolation of prion strains to exceptional levels of purity from small quantities of infected brain and demonstrate faithful retention of biological and biochemical strain properties. The method's effectiveness and simplicity should facilitate its wide application and expedite structural studies of prions.
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Affiliation(s)
- Adam Wenborn
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Cassandra Terry
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Nathalie Gros
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Susan Joiner
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Laura D'Castro
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Silvia Panico
- Department of Crystallography and Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
| | - Jessica Sells
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Sabrina Cronier
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jacqueline M Linehan
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Sebastian Brandner
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Helen R Saibil
- Department of Crystallography and Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Jonathan D F Wadsworth
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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18
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Gorovits R, Moshe A, Ghanim M, Czosnek H. Degradation mechanisms of the Tomato yellow leaf curl virus coat protein following inoculation of tomato plants by the whitefly Bemisia tabaci. PEST MANAGEMENT SCIENCE 2014; 70:1632-9. [PMID: 24464776 DOI: 10.1002/ps.3737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/16/2014] [Indexed: 05/10/2023]
Abstract
BACKGROUND Tomato yellow leaf curl virus (TYLCV) is a begomovirus infecting tomato cultures worldwide. TYLCV is transmitted to plants by the whitefly Bemisia tabaci. Once in the plant, the virus is subjected to attack by the host-plant defences, which may include sequestration in aggregates, proteolysis, ubiquitination, 26S proteasome degradation and autophagy. Elucidating how the virus avoids destruction will make it possible to understand infection and possibly devise countermeasures. RESULTS The accumulation of viral coat protein (CP) and of viral DNA in plants is a marker of a successful virus transmission by B. tabaci. In response to infection, tomato tissues display multiple ways of degrading TYLCV proteins and DNA. In this study it is shown that CP (in soluble and insoluble states) is the target of protease digestion, 26S proteasome degradation and autophagy. The highest degradation capacity was detected among soluble proteins and proteins in large aggregates/inclusion bodies; cytoplasmic extracts displayed higher activity than nuclear fractions. The very same fractions possessed the highest capacity to degrade viral genomic DNA. Separately, 26S proteasome degradation was associated with large aggregates (more pronounced in the nuclear than in the cytoplasmic fractions), which are indicators of a successful abduction of plants by viruses. Autophagy/lysosome/vacuole degradation was a characteristic of intermediate aggregates, sequestering the CP in the cytoplasm and retarding the development of large aggregates. Chloroplast proteases were active in soluble as well as in insoluble protein extracts. CONCLUSIONS To the best of the authors' knowledge, this study is the first attempt to identify elements of the virus-targeted degradation machinery, which is a part of the plant response to virus invasion.
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Affiliation(s)
- Rena Gorovits
- Institute of Plant Sciences and Genetics in Agriculture and the Otto Warburg Minerva Centre for Agricultural Biotechnology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
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19
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Prion neuropathology follows the accumulation of alternate prion protein isoforms after infective titre has peaked. Nat Commun 2014; 5:4347. [PMID: 25005024 PMCID: PMC4104459 DOI: 10.1038/ncomms5347] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/09/2014] [Indexed: 01/02/2023] Open
Abstract
Prions are lethal infectious agents thought to consist of multi-chain forms (PrPSc) of misfolded cellular prion protein (PrPC). Prion propagation proceeds in two distinct mechanistic phases: an exponential phase 1, which rapidly reaches a fixed level of infectivity irrespective of PrPC expression level, and a plateau (phase 2), which continues until clinical onset with duration inversely proportional to PrPC expression level. We hypothesized that neurotoxicity relates to distinct neurotoxic species produced following a pathway switch when prion levels saturate. Here we show a linear increase of proteinase K-sensitive PrP isoforms distinct from classical PrPSc at a rate proportional to PrPC concentration, commencing at the phase transition and rising until clinical onset. The unaltered level of total PrP during phase 1, when prion infectivity increases a million-fold, indicates that prions comprise a small minority of total PrP. This is consistent with PrPC concentration not being rate limiting to exponential prion propagation and neurotoxicity relating to critical concentrations of alternate PrP isoforms whose production is PrPC concentration dependent. Prions (PrP) are infectious agents that cause lethal neurodegenerative diseases. Here the authors study the kinetics of prion propagation in mice and show that the onset of neuropathology occurs during the late phase of disease and is hypothesized to be due to increases in a toxic isoform of PrP that is different from the infectious species.
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20
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Godsave SF, Wille H, Pierson J, Prusiner SB, Peters PJ. Plasma membrane invaginations containing clusters of full-length PrPSc are an early form of prion-associated neuropathology in vivo. Neurobiol Aging 2013; 34:1621-31. [PMID: 23481568 DOI: 10.1016/j.neurobiolaging.2012.12.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/19/2012] [Accepted: 12/20/2012] [Indexed: 10/27/2022]
Abstract
During prion disease, cellular prion protein (PrP(C)) is refolded into a pathogenic isoform (PrP(Sc)) that accumulates in the central nervous system and causes neurodegeneration and death. We used immunofluorescence, quantitative cryo-immunogold EM, and tomography to detect nascent, full-length PrP(Sc) in the hippocampus of prion-infected mice from early preclinical disease stages onward. Comparison of uninfected and infected brains showed that sites containing full-length PrP(Sc) could be recognized in the neuropil by bright spots and streaks of immunofluorescence on semi-thin (200-nm) sections, and by clusters of cryo-immunogold EM labeling. PrP(Sc) was found mainly on neuronal plasma membranes, most strikingly on membrane invaginations and sites of cell-to-cell contact, and was evident by 65 days postinoculation, or 54% of the incubation period to terminal disease. Both axons and dendrites in the neuropil were affected. We hypothesize that closely apposed plasma membranes provide a favorable environment for prion conversion and intercellular prion transfer. Only a small proportion of clustered PrP immunogold labeling was found at synapses, indicating that synapses are not targeted specifically in prion disease.
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Affiliation(s)
- Susan F Godsave
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, the Netherlands
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21
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Elder AM, Henderson DM, Nalls AV, Wilham JM, Caughey BW, Hoover EA, Kincaid AE, Bartz JC, Mathiason CK. In vitro detection of prionemia in TSE-infected cervids and hamsters. PLoS One 2013; 8:e80203. [PMID: 24224043 PMCID: PMC3815098 DOI: 10.1371/journal.pone.0080203] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/30/2013] [Indexed: 01/01/2023] Open
Abstract
Blood-borne transmission of infectious prions during the symptomatic and asymptomatic stages of disease occurs for both human and animal transmissible spongiform encephalopathies (TSEs). The geographical distribution of the cervid TSE, chronic wasting disease (CWD), continues to spread across North America and the prospective number of individuals harboring an asymptomatic infection of human variant Creutzfeldt-Jakob Disease (vCJD) in the United Kingdom has been projected to be ~1 in 3000 residents. Thus, it is important to monitor cervid and human blood products to ensure herd health and human safety. Current methods for detecting blood-associated prions rely primarily upon bioassay in laboratory animals. While bioassay provides high sensitivity and specificity, it requires many months, animals, and it is costly. Here we report modification of the real time quaking-induced conversion (RT-QuIC) assay to detect blood-borne prions in whole blood from prion-infected preclinical white-tailed deer, muntjac deer, and Syrian hamsters, attaining sensitivity of >90% while maintaining 100% specificity. Our results indicate that RT-QuIC methodology as modified can provide consistent and reliable detection of blood-borne prions in preclinical and symptomatic stages of two animal TSEs, offering promise for prionemia detection in other species, including humans.
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Affiliation(s)
- Alan M. Elder
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Davin M. Henderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Amy V. Nalls
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jason M. Wilham
- Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Byron W. Caughey
- Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Edward A. Hoover
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Anthony E. Kincaid
- Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Jason C. Bartz
- Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Candace K. Mathiason
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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22
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Klöhn PC, Castro-Seoane R, Collinge J. Exosome release from infected dendritic cells: a clue for a fast spread of prions in the periphery? J Infect 2013; 67:359-68. [PMID: 23911964 DOI: 10.1016/j.jinf.2013.07.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/11/2013] [Accepted: 07/23/2013] [Indexed: 11/18/2022]
Abstract
Prion diseases are incurable transmissible neurological disorders. In many natural and experimental prion diseases, infectious prions can be detected in the lymphoreticular system (LRS) long before they reach the brain where they cause a fatal rapidly progressive degeneration. Although major cell types that contribute to prion accumulation have been identified, the mode of prion dissemination in the LRS remains elusive. Recent evidence of a remarkably fast splenic prion accumulation after peripheral infection of mice, resulting in high prion titers in dendritic cells (DCs) and a release of prions from infected DCs via exosomes suggest that intercellular dissemination may contribute to rapid prion colonization in the LRS. A vast body of evidence from retroviral infections shows that DCs and other antigen-presenting cells (APCs) share viral antigens by intercellular transfer to warrant immunity against viruses if APCs remain uninfected. Evolved to adapt the immune response to evading pathogens, these pathways may constitute a portal for unimpeded prion dissemination owing to the tolerance of the immune system against host-encoded prion protein. In this review we summarize current paradigms for antigen-sharing pathways which may be relevant to better understand dissemination of rogue neurotoxic proteins.
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Affiliation(s)
- Peter-Christian Klöhn
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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23
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Henderson DM, Manca M, Haley NJ, Denkers ND, Nalls AV, Mathiason CK, Caughey B, Hoover EA. Rapid antemortem detection of CWD prions in deer saliva. PLoS One 2013; 8:e74377. [PMID: 24040235 PMCID: PMC3770611 DOI: 10.1371/journal.pone.0074377] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/31/2013] [Indexed: 11/29/2022] Open
Abstract
Chronic wasting disease (CWD) is an efficiently transmitted prion disease of cervids, now identified in 22 United States, 2 Canadian provinces and Korea. One hallmark of CWD is the shedding of infectious prions in saliva, as demonstrated by bioassay in deer. It is also clear that the concentration of prions in saliva, blood, urine and feces is much lower than in the nervous system or lymphoid tissues. Rapid in vitro detection of CWD (and other) prions in body fluids and excreta has been problematic due to the sensitivity limits of direct assays (western blotting, ELISA) and the presence of inhibitors in these complex biological materials that hamper detection. Here we use real-time quaking induced conversion (RT-QuIC) to demonstrate CWD prions in both diluted and prion-enriched saliva samples from asymptomatic and symptomatic white-tailed deer. CWD prions were detected in 14 of 24 (58.3%) diluted saliva samples from CWD-exposed white-tailed deer, including 9 of 14 asymptomatic animals (64.2%). In addition, a phosphotungstic acid enrichment enhanced the RT-QuIC assay sensitivity, enabling detection in 19 of 24 (79.1%) of the above saliva samples. Bioassay in Tg[CerPrP] mice confirmed the presence of infectious prions in 2 of 2 RT-QuIC-positive saliva samples so examined. The modified RT-QuIC analysis described represents a non-invasive, rapid ante-mortem detection of prions in complex biologic fluids, excreta, or environmental samples as well as a tool for exploring prion trafficking, peripheralization, and dissemination.
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Affiliation(s)
- Davin M. Henderson
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
| | - Matteo Manca
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories (RML), National Institute of Allergy and Infectious Disease, Hamilton, Montana, United States of America
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Nicholas J. Haley
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
| | - Nathaniel D. Denkers
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
| | - Amy V. Nalls
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
| | - Candace K. Mathiason
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
| | - Byron Caughey
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories (RML), National Institute of Allergy and Infectious Disease, Hamilton, Montana, United States of America
| | - Edward A. Hoover
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University (CSU), Fort Collins, Colorado, United States of America
- * E-mail:
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24
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Salamat MK, Munoz-Montesino C, Moudjou M, Rezaei H, Laude H, Béringue V, Dron M. Mammalian prions: tolerance to sequence changes-how far? Prion 2012; 7:131-5. [PMID: 23232499 DOI: 10.4161/pri.23110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Upon prion infection, abnormal prion protein (PrP (Sc) ) self-perpetuate by conformational conversion of α-helix-rich PrP (C) into β sheet enriched form, leading to formation and deposition of PrP (Sc) aggregates in affected brains. However the process remains poorly understood at the molecular level and the regions of PrP critical for conversion are still debated. Minimal amino acid substitutions can impair prion replication at many places in PrP. Conversely, we recently showed that bona fide prions could be generated after introduction of eight and up to 16 additional amino acids in the H2-H3 inter-helix loop of PrP. Prion replication also accommodated the insertions of an octapeptide at different places in the last turns of H2. This reverse genetic approach reveals an unexpected tolerance of prions to substantial sequence changes in the protease-resistant part which is associated with infectivity. It also demonstrates that conversion does not require the presence of a specific sequence in the middle of the H2-H3 area. We discuss the implications of our findings according to different structural models proposed for PrP (Sc) and questioned the postulated existence of an N- or C-terminal prion domain in the protease-resistant region.
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25
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Miyazawa K, Emmerling K, Manuelidis L. High CJD infectivity remains after prion protein is destroyed. J Cell Biochem 2012; 112:3630-7. [PMID: 21793041 DOI: 10.1002/jcb.23286] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The hypothesis that host prion protein (PrP) converts into an infectious prion form rests on the observation that infectivity progressively decreases in direct proportion to the decrease of PrP with proteinase K (PK) treatment. PrP that resists limited PK digestion (PrP-res, PrP(sc)) has been assumed to be the infectious form, with speculative types of misfolding encoding the many unique transmissible spongiform encephalopathy (TSE) agent strains. Recently, a PK sensitive form of PrP has been proposed as the prion. Thus we re-evaluated total PrP (sensitive and resistant) and used a cell-based assay for titration of infectious particles. A keratinase (NAP) known to effectively digest PrP was compared to PK. Total PrP in FU-CJD infected brain was reduced to ≤0.3% in a 2 h PK digest, yet there was no reduction in titer. Remaining non-PrP proteins were easily visualized with colloidal gold in this highly infectious homogenate. In contrast to PK, NAP digestion left 0.8% residual PrP after 2 h, yet decreased titer by >2.5 log; few residual protein bands remained. FU-CJD infected cells with 10× the infectivity of brain by both animal and cell culture assays were also evaluated. NAP again significantly reduced cell infectivity (>3.5 log). Extreme PK digestions were needed to reduce cell PrP to <0.2%, yet a very high titer of 8 logs survived. Our FU-CJD brain results are in good accord with the only other report on maximal PrP destruction and titer. It is likely that one or more residual non-PrP proteins may protect agent nucleic acids in infectious particles.
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Affiliation(s)
- Kohtaro Miyazawa
- Department of Surgery, Yale Medical School, New Haven, Connecticut 06511, USA
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26
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Kubota T, Hamazoe Y, Hashiguchi S, Ishibashi D, Akasaka K, Nishida N, Katamine S, Sakaguchi S, Kuroki R, Nakashima T, Sugimura K. Direct evidence of generation and accumulation of β-sheet-rich prion protein in scrapie-infected neuroblastoma cells with human IgG1 antibody specific for β-form prion protein. J Biol Chem 2012; 287:14023-39. [PMID: 22356913 DOI: 10.1074/jbc.m111.318352] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We prepared β-sheet-rich recombinant full-length prion protein (β-form PrP) (Jackson, G. S., Hosszu, L. L., Power, A., Hill, A. F., Kenney, J., Saibil, H., Craven, C. J., Waltho, J. P., Clarke, A. R., and Collinge, J. (1999) Science 283, 1935-1937). Using this β-form PrP and a human single chain Fv-displaying phage library, we have established a human IgG1 antibody specific to β-form but not α-form PrP, PRB7 IgG. When prion-infected ScN2a cells were cultured with PRB7 IgG, they generated and accumulated PRB7-binding granules in the cytoplasm with time, consequently becoming apoptotic cells bearing very large PRB7-bound aggregates. The SAF32 antibody recognizing the N-terminal octarepeat region of full-length PrP stained distinct granules in these cells as determined by confocal laser microscopy observation. When the accumulation of proteinase K-resistant PrP was examined in prion-infected ScN2a cells cultured in the presence of PRB7 IgG or SAF32, it was strongly inhibited by SAF32 but not at all by PRB7 IgG. Thus, we demonstrated direct evidence of the generation and accumulation of β-sheet-rich PrP in ScN2a cells de novo. These results suggest first that PRB7-bound PrP is not responsible for the accumulation of β-form PrP aggregates, which are rather an end product resulting in the triggering of apoptotic cell death, and second that SAF32-bound PrP lacking the PRB7-recognizing β-form may represent so-called PrP(Sc) with prion propagation activity. PRB7 is the first human antibody specific to β-form PrP and has become a powerful tool for the characterization of the biochemical nature of prion and its pathology.
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Affiliation(s)
- Toshiya Kubota
- Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan
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27
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Castro-Seoane R, Hummerich H, Sweeting T, Tattum MH, Linehan JM, Fernandez de Marco M, Brandner S, Collinge J, Klöhn PC. Plasmacytoid dendritic cells sequester high prion titres at early stages of prion infection. PLoS Pathog 2012; 8:e1002538. [PMID: 22359509 PMCID: PMC3280992 DOI: 10.1371/journal.ppat.1002538] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 01/04/2012] [Indexed: 12/22/2022] Open
Abstract
In most transmissible spongiform encephalopathies prions accumulate in the lymphoreticular system (LRS) long before they are detectable in the central nervous system. While a considerable body of evidence showed that B lymphocytes and follicular dendritic cells play a major role in prion colonization of lymphoid organs, the contribution of various other cell types, including antigen-presenting cells, to the accumulation and the spread of prions in the LRS are not well understood. A comprehensive study to compare prion titers of candidate cell types has not been performed to date, mainly due to limitations in the scope of animal bioassays where prohibitively large numbers of mice would be required to obtain sufficiently accurate data. By taking advantage of quantitative in vitro prion determination and magnetic-activated cell sorting, we studied the kinetics of prion accumulation in various splenic cell types at early stages of prion infection. Robust estimates for infectious titers were obtained by statistical modelling using a generalized linear model. Whilst prions were detectable in B and T lymphocytes and in antigen-presenting cells like dendritic cells and macrophages, highest infectious titers were determined in two cell types that have previously not been associated with prion pathogenesis, plasmacytoid dendritic (pDC) and natural killer (NK) cells. At 30 days after infection, NK cells were more than twice, and pDCs about seven-fold, as infectious as lymphocytes respectively. This result was unexpected since, in accordance to previous reports prion protein, an obligate requirement for prion replication, was undetectable in pDCs. This underscores the importance of prion sequestration and dissemination by antigen-presenting cells which are among the first cells of the immune system to encounter pathogens. We furthermore report the first evidence for a release of prions from lymphocytes and DCs of scrapie-infected mice ex vivo, a process that is associated with a release of exosome-like membrane vesicles.
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Affiliation(s)
- Rocio Castro-Seoane
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Holger Hummerich
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Trevor Sweeting
- Department of Statistical Science, University College London, London, United Kingdom
| | - M. Howard Tattum
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Jacqueline M. Linehan
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Mar Fernandez de Marco
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Sebastian Brandner
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
| | - Peter-Christian Klöhn
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom
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28
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Akhtar S, Wenborn A, Brandner S, Collinge J, Lloyd SE. Sex effects in mouse prion disease incubation time. PLoS One 2011; 6:e28741. [PMID: 22174884 PMCID: PMC3236759 DOI: 10.1371/journal.pone.0028741] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 11/14/2011] [Indexed: 11/18/2022] Open
Abstract
Prion disease incubation time in mice is determined by many factors including PrP expression level, Prnp alleles, genetic background, prion strain and route of inoculation. Sex differences have been described in age of onset for vCJD and in disease duration for both vCJD and sporadic CJD and have also been shown in experimental models. The sex effects reported for mouse incubation times are often contradictory and detail only one strain of mice or prions, resulting in broad generalisations and a confusing picture. To clarify the effect of sex on prion disease incubation time in mice we have compared male and female transmission data from twelve different inbred lines of mice inoculated with at least two prion strains, representing both mouse-adapted scrapie and BSE. Our data show that sex can have a highly significant difference on incubation time. However, this is limited to particular mouse and prion strain combinations. No sex differences were seen in endogenous PrPC levels nor in the neuropathological markers of prion disease: PrPSc distribution, spongiosis, neuronal loss and gliosis. These data suggest that when comparing incubation times between experimental groups, such as testing the effects of modifier genes or therapeutics, single sex groups should be used.
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Affiliation(s)
- Shaheen Akhtar
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, London, United Kingdom
| | - Adam Wenborn
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, London, United Kingdom
| | - Sebastian Brandner
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, London, United Kingdom
| | - John Collinge
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, London, United Kingdom
| | - Sarah E. Lloyd
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, University College London Institute of Neurology, London, United Kingdom
- * E-mail:
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29
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Browning S, Baker CA, Smith E, Mahal SP, Herva ME, Demczyk CA, Li J, Weissmann C. Abrogation of complex glycosylation by swainsonine results in strain- and cell-specific inhibition of prion replication. J Biol Chem 2011; 286:40962-73. [PMID: 21930694 PMCID: PMC3220511 DOI: 10.1074/jbc.m111.283978] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 08/30/2011] [Indexed: 11/06/2022] Open
Abstract
Neuroblastoma-derived N2a-PK1 cells, fibroblastic LD9 cells, and CNS-derived CAD5 cells can be infected efficiently and persistently by various prion strains, as measured by the standard scrapie cell assay. Swainsonine, an inhibitor of Golgi α-mannosidase II that causes abnormal N-glycosylation, strongly inhibits infection of PK1 cells by RML, 79A and 22F, less so by 139A, and not at all by 22L prions, and it does not diminish propagation of any of these strains in LD9 or CAD5 cells. Misglycosylated PrP(C) formed in the presence of swainsonine is a good substrate for conversion to PrP(Sc), and misglycosylated PrP(Sc) is fully able to trigger infection and seed the protein misfolding cyclic amplification reaction. Distinct subclones of PK1 cells mediate swainsonine inhibition to very different degrees, implicating misglycosylation of one or more host proteins in the inhibitory process. The use of swainsonine and other glycosylation inhibitors described herein enhances the ability of the cell panel assay to differentiate between prion strains. Moreover, as shown elsewhere, the susceptibility of prions to inhibition by swainsonine in PK1 cells is a mutable trait.
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Affiliation(s)
- Shawn Browning
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | | | - Emery Smith
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | - Sukhvir P. Mahal
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | - Maria E. Herva
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | - Cheryl A. Demczyk
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | - Jiali Li
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
| | - Charles Weissmann
- From the Department of Infectology, Scripps Florida, Jupiter, Florida 33458
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30
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Weissmann C, Li J, Mahal SP, Browning S. Prions on the move. EMBO Rep 2011; 12:1109-17. [PMID: 21997298 PMCID: PMC3207107 DOI: 10.1038/embor.2011.192] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 08/30/2011] [Indexed: 02/07/2023] Open
Abstract
Prions consist mainly, if not entirely, of PrP(Sc), an aggregated conformer of the host protein PrP(C). Prions come in different strains, all based on the same PrP(C) sequence, but differing in their conformations. The efficiency of prion transmission between species is usually low, but increases after serial transmission in the new host, suggesting a process involving mutation and selection. Even within the same species, the transfer of prions between cell types entails a selection of favoured 'substrains', and propagation of prions in the presence of an inhibitory drug can result in the appearance of drug-resistant prion populations. We propose that prion populations are comprised of a variety of conformers, constituting 'quasi-species', from which the one replicating most efficiently in a particular environment is selected.
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Affiliation(s)
- Charles Weissmann
- Department of Infectology, Scripps Florida, 130 Scripps Way, Jupiter, Florida 33458, USA.
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31
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A simple, versatile and sensitive cell-based assay for prions from various species. PLoS One 2011; 6:e20563. [PMID: 21655184 PMCID: PMC3105100 DOI: 10.1371/journal.pone.0020563] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/03/2011] [Indexed: 12/03/2022] Open
Abstract
Detection and quantification of prion infectivity is a crucial step for various fundamental and applied aspects of prion research. Identification of cell lines highly sensitive to prion infection led to the development of cell-based titration procedures aiming at replacing animal bioassays, usually performed in mice or hamsters. However, most of these cell lines are only permissive to mouse-adapted prions strains and do not allow titration of prions from other species. In this study, we show that epithelial RK13, a cell line permissive to mouse and bank vole prion strains and to natural prion agents from sheep and cervids, enables a robust and sensitive detection of mouse and ovine-derived prions. Importantly, the cell culture work is strongly reduced as the RK13 cell assay procedure designed here does not require subcultivation of the inoculated cultures. We also show that prions effectively bind to culture plastic vessel and are quantitatively detected by the cell assay. The possibility to easily quantify a wider range of prions, including rodent experimental strains but also natural agents from sheep and cervids, should prompt the spread of cell assays for routine prion titration and lead to valuable information in fundamental and applied studies.
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32
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Savistchenko J, Arellano-Anaya ZE, Andréoletti O, Vilette D. Mammalian prions: tracking the infectious entities. Prion 2011; 5:84-7. [PMID: 21597318 DOI: 10.4161/pri.5.2.16096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Protein misfolding is central to the pathogenesis of several neurodegenerative disorders. Among these disorders, prion diseases are unique because they are transmissible. The conversion of the host-encoded GPI-anchored PrP protein into a structurally altered form is crucially associated with the infectious and neurotoxic properties of the resulting abnormal PrP. Many lines of evidence indicate that distinct aggregated forms with different size and protease resistance are produced during prion multiplication. The recent isolation of various subsets of abnormal PrP, along with the improved biochemical tools and infectivity detection assays have shed light on the diversity of abnormal PrP protein and may give insights into the features of the more infectious subsets of abnormal PrP.
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Affiliation(s)
- Jimmy Savistchenko
- UMR INRA ENVT 1225, Interactions Hôte Agent Pathogène, Ecole Nationale Vétérinaire de Toulouse, France
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