1
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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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Wu J, Wang X, Lakkaraju A, Sternke-Hoffmann R, Qureshi BM, Aguzzi A, Luo J. Channel Activities of the Full-Length Prion and Truncated Proteins. ACS Chem Neurosci 2024; 15:98-107. [PMID: 38096481 DOI: 10.1021/acschemneuro.3c00412] [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] [Indexed: 01/04/2024] Open
Abstract
Prion diseases are fatal neurodegenerative disorders characterized by the conversion of the cellular prion protein (PrPC) into a misfolded prion form, which is believed to disrupt the cellular membranes. However, the exact mechanisms underlying prion toxicity, including the formation of membrane pores, are not fully understood. The prion protein consists of two domains: a globular domain (GD) and a flexible N-terminus (FT) domain. Although a proximal polybasic amino acid (FT(23-31) sequence of FT is a prerequisite for cellular membrane permeabilization, other functional domain regions may modulate its effects. Through single-channel electrical recordings and cryo-electron microscopy (cryo-EM), we discovered that the FT(23-50) fragment forms pore-shaped oligomers and plays a dominant role in membrane permeabilization within the full-length mouse prion protein (mPrP(23-230)). In contrast, the FT(51-110) domain or the C-terminal domain downregulate the channel activity of FT(23-50) and mPrP(23-230). The addition of prion mimetic antibody, POM1 significantly amplifies mPrP(23-230) membrane permeabilization, whereas POM1_Y104A, a mutant that binds to PrP but cannot elicit toxicity, has a negligible effect on membrane permeabilization. Additionally, the anti-N-terminal antibody POM2 or Cu2+ binds to the FT domain, subsequently enhancing the FT(23-110) channel activity. Importantly, our setup provides a novel approach without an external fused protein to examine the channel activity of truncated PrP in the lipid membranes. We therefore propose that the primary N-terminal residues are essential for membrane permeabilization, while other functional segments of PrP play a vital role in modulating the pathological effects of PrP-mediated neurotoxicity.
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Affiliation(s)
- Jinming Wu
- Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Xue Wang
- Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Asvin Lakkaraju
- Institute of Neuropathology, University of Zurich and University Hospital Zurich, Zurich 8091, Switzerland
| | | | - Bilal M Qureshi
- Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich 8093, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich and University Hospital Zurich, Zurich 8091, Switzerland
| | - Jinghui Luo
- Department of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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3
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Shim KH, Sharma N, An SSA. Prion therapeutics: Lessons from the past. Prion 2022; 16:265-294. [PMID: 36515657 PMCID: PMC9754114 DOI: 10.1080/19336896.2022.2153551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 12/15/2022] Open
Abstract
Prion diseases are a group of incurable zoonotic neurodegenerative diseases (NDDs) in humans and other animals caused by the prion proteins. The abnormal folding and aggregation of the soluble cellular prion proteins (PrPC) into scrapie isoform (PrPSc) in the Central nervous system (CNS) resulted in brain damage and other neurological symptoms. Different therapeutic approaches, including stalling PrPC to PrPSc conversion, increasing PrPSc removal, and PrPC stabilization, for which a spectrum of compounds, ranging from organic compounds to antibodies, have been explored. Additionally, a non-PrP targeted drug strategy using serpin inhibitors has been discussed. Despite numerous scaffolds being screened for anti-prion activity in vitro, only a few were effective in vivo and unfortunately, almost none of them proved effective in the clinical studies, most likely due to toxicity and lack of permeability. Recently, encouraging results from a prion-protein monoclonal antibody, PRN100, were presented in the first human trial on CJD patients, which gives a hope for better future for the discovery of other new molecules to treat prion diseases. In this comprehensive review, we have re-visited the history and discussed various classes of anti-prion agents, their structure, mode of action, and toxicity. Understanding pathogenesis would be vital for developing future treatments for prion diseases. Based on the outcomes of existing therapies, new anti-prion agents could be identified/synthesized/designed with reduced toxicity and increased bioavailability, which could probably be effective in treating prion diseases.
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Affiliation(s)
- Kyu Hwan Shim
- Department of Bionano Technology, Gachon University, Seongnam, South Korea
| | - Niti Sharma
- Department of Bionano Technology, Gachon University, Seongnam, South Korea
| | - Seong Soo A An
- Department of Bionano Technology, Gachon University, Seongnam, South Korea
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4
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Reimann RR, Puzio M, Rosati A, Emmenegger M, Schneider BL, Valdés P, Huang D, Caflisch A, Aguzzi A. Rapid ex vivo reverse genetics identifies the essential determinants of prion protein toxicity. Brain Pathol 2022; 33:e13130. [PMID: 36329611 PMCID: PMC10041163 DOI: 10.1111/bpa.13130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
Abstract
The cellular prion protein PrPC mediates the neurotoxicity of prions and other protein aggregates through poorly understood mechanisms. Antibody-derived ligands against the globular domain of PrPC (GDL) can also initiate neurotoxicity by inducing an intramolecular R208 -H140 hydrogen bond ("H-latch") between the α2-α3 and β2-α2 loops of PrPC . Importantly, GDL that suppresses the H-latch prolong the life of prion-infected mice, suggesting that GDL toxicity and prion infections exploit convergent pathways. To define the structural underpinnings of these phenomena, we transduced 19 individual PrPC variants to PrPC -deficient cerebellar organotypic cultured slices using adenovirus-associated viral vectors (AAV). We report that GDL toxicity requires a single N-proximal cationic residue (K27 or R27 ) within PrPC . Alanine substitution of K27 also prevented the toxicity of PrPC mutants that induce Shmerling syndrome, a neurodegenerative disease that is suppressed by co-expression of wild-type PrPC . K27 may represent an actionable target for compounds aimed at preventing prion-related neurodegeneration.
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Affiliation(s)
| | - Martina Puzio
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Antonella Rosati
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Marc Emmenegger
- Institute of Neuropathology University of Zurich Zurich Switzerland
| | - Bernard L. Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Pamela Valdés
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne Switzerland
| | - Danzhi Huang
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry University of Zürich Zürich Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology University of Zurich Zurich Switzerland
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5
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A conformational switch controlling the toxicity of the prion protein. Nat Struct Mol Biol 2022; 29:831-840. [PMID: 35948768 PMCID: PMC9371974 DOI: 10.1038/s41594-022-00814-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 07/06/2022] [Indexed: 11/08/2022]
Abstract
Prion infections cause conformational changes of the cellular prion protein (PrPC) and lead to progressive neurological impairment. Here we show that toxic, prion-mimetic ligands induce an intramolecular R208-H140 hydrogen bond ('H-latch'), altering the flexibility of the α2-α3 and β2-α2 loops of PrPC. Expression of a PrP2Cys mutant mimicking the H-latch was constitutively toxic, whereas a PrPR207A mutant unable to form the H-latch conferred resistance to prion infection. High-affinity ligands that prevented H-latch induction repressed prion-related neurodegeneration in organotypic cerebellar cultures. We then selected phage-displayed ligands binding wild-type PrPC, but not PrP2Cys. These binders depopulated H-latched conformers and conferred protection against prion toxicity. Finally, brain-specific expression of an antibody rationally designed to prevent H-latch formation prolonged the life of prion-infected mice despite unhampered prion propagation, confirming that the H-latch is an important reporter of prion neurotoxicity.
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6
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Shafiq M, Da Vela S, Amin L, Younas N, Harris DA, Zerr I, Altmeppen HC, Svergun D, Glatzel M. The prion protein and its ligands: Insights into structure-function relationships. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119240. [PMID: 35192891 DOI: 10.1016/j.bbamcr.2022.119240] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/23/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
The prion protein is a multifunctional protein that exists in at least two different folding states. It is subject to diverse proteolytic processing steps that lead to prion protein fragments some of which are membrane-bound whereas others are soluble. A multitude of ligands bind to the prion protein and besides proteinaceous binding partners, interaction with metal ions and nucleic acids occurs. Although of great importance, information on structural and functional consequences of prion protein binding to its partners is limited. Here, we will reflect on the structure-function relationship of the prion protein and its binding partners considering the different folding states and prion protein fragments.
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Affiliation(s)
- Mohsin Shafiq
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany
| | - Stefano Da Vela
- European Molecular Biology Laboratory (EMBL), Hamburg c/o German Electron Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Ladan Amin
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Neelam Younas
- Department of Neurology, University Medical Center Goettingen, Robert-Koch-str. 40, 37075 Goettingen, Germany
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Inga Zerr
- Department of Neurology, University Medical Center Goettingen, Robert-Koch-str. 40, 37075 Goettingen, Germany
| | - Hermann C Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany
| | - Dmitri Svergun
- European Molecular Biology Laboratory (EMBL), Hamburg c/o German Electron Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany.
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7
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Adhikari UK, Tayebi M. Epitope-specific anti-PrP antibody toxicity: a comparative in-silico study of human and mouse prion proteins. Prion 2021; 15:155-176. [PMID: 34632945 PMCID: PMC8900626 DOI: 10.1080/19336896.2021.1964326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Despite having therapeutic potential, anti-PrP antibodies caused a major controversy due to their neurotoxic effects. For instance, treating mice with ICSM antibodies delayed prion disease onset, but both were found to be either toxic or innocuous to neurons by researchers following cross-linking PrPC. In order to elucidate and understand the reasons that led to these contradictory outcomes, we conducted a comprehensive in silico study to assess the antibody-specific toxicity. Since most therapeutic anti-PrP antibodies were generated against human truncated recombinant PrP91-231 or full-length mouse PrP23-231, we reasoned that host specificity (human vs murine) of PrPC might influence the nature of the specific epitopes recognized by these antibodies at the structural level possibly explaining the 'toxicity' discrepancies reported previously. Initially, molecular dynamics simulation and pro-motif analysis of full-length human (hu)PrP and mouse (mo)PrP 3D structure displayed conspicuous structural differences between huPrP and moPrP. We identified 10 huPrP and 6 moPrP linear B-cell epitopes from the prion protein 3D structure where 5 out of 10 huPrP and 3 out of 6 moPrP B-cell epitopes were predicted to be potentially toxic in immunoinformatics approaches. Herein, we demonstrate that some of the predicted potentially 'toxic' epitopes identified by the in silico analysis were similar to the epitopes recognized by the toxic antibodies such as ICSM18 (146-159), POM1 (138-147), D18 (133-157), ICSM35 (91-110), D13 (95-103) and POM3 (95-100). This in silico study reveals the role of host specificity of PrPC in epitope-specific anti-PrP antibody toxicity.
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Affiliation(s)
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
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8
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Li B, Chen M, Aguzzi A, Zhu C. The role of macrophage scavenger receptor 1 (Msr1) in prion pathogenesis. J Mol Med (Berl) 2021; 99:877-887. [PMID: 33758958 PMCID: PMC8164582 DOI: 10.1007/s00109-021-02061-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/01/2021] [Accepted: 03/07/2021] [Indexed: 11/01/2022]
Abstract
The progression of prion diseases is accompanied by the accumulation of prions in the brain. Ablation of microglia enhances prion accumulation and accelerates disease progression, suggesting that microglia play a neuroprotective role by clearing prions. However, the mechanisms underlying the phagocytosis and clearance of prion are largely unknown. The macrophage scavenger receptor 1 (Msr1) is an important phagocytic receptor expressed by microglia in the brain and is involved in the uptake and clearance of soluble amyloid-β. We therefore asked whether Msr1 might play a role in prion clearance and assessed the scavenger function of Msr1 in prion pathogenesis. We found that Msr1 expression was upregulated in prion-infected mouse brains. However, Msr1 deficiency did not change prion disease progression or lesion patterns. Prion deposition in Msr1 deficient mice was similar to their wild-type littermates. In addition, prion-induced neuroinflammation was not affected by Msr1 ablation. We conclude that Msr1 does not play a major role in prion pathogenesis. KEY MESSAGES: Msr1 expression is upregulated in prion-infected mouse brains at the terminal stage Msr1 deficiency does not affect prion disease progression Msr1 does not play a major role in prion clearance or prion pathogenesis Microglia-mediated phagocytosis and clearance of Aβ and prion may adopt distinct molecular pathways.
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Affiliation(s)
- Bei Li
- School of Basic Medical Sciences, Fudan University, Dong'An Road 130, Shanghai, 200032, China
| | - Meiling Chen
- School of Basic Medical Sciences, Fudan University, Dong'An Road 130, Shanghai, 200032, China
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091, Zurich, Switzerland.
| | - Caihong Zhu
- School of Basic Medical Sciences, Fudan University, Dong'An Road 130, Shanghai, 200032, China.
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9
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Chen C, Dong X. Therapeutic implications of prion diseases. BIOSAFETY AND HEALTH 2021. [DOI: 10.1016/j.bsheal.2020.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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10
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Recent developments in antibody therapeutics against prion disease. Emerg Top Life Sci 2020; 4:169-173. [PMID: 32633322 DOI: 10.1042/etls20200002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/15/2020] [Accepted: 06/17/2020] [Indexed: 12/21/2022]
Abstract
Preclinical evidence indicates that prion diseases can respond favorably to passive immunotherapy. However, certain antibodies to the cellular prion protein PrPC can be toxic. Comprehensive studies of structure-function relationships have revealed that the flexible amino-terminal tail of PrPC is instrumental for mediating prion toxicity. In a first-in-human study, an anti-prion antibody has been recently administered to patients diagnosed with sporadic Creutzfeldt-Jakob's disease, the most prevalent human prion disease. Moreover, large-scale serosurveys have mapped the prevalence of naturally occurring human anti-prion autoantibodies in health and disease. Here, we provide a perspective on the limitations and opportunities of therapeutic anti-prion antibodies.
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11
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Avar M, Heinzer D, Steinke N, Doğançay B, Moos R, Lugan S, Cosenza C, Hornemann S, Andréoletti O, Aguzzi A. Prion infection, transmission, and cytopathology modeled in a low-biohazard human cell line. Life Sci Alliance 2020; 3:3/8/e202000814. [PMID: 32606072 PMCID: PMC7335386 DOI: 10.26508/lsa.202000814] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 12/19/2022] Open
Abstract
Expanding the toolbox of prion research to a low-biohazard, scalable human cell model. Transmission of prion infectivity to susceptible murine cell lines has simplified prion titration assays and has greatly reduced the need for animal experimentation. However, murine cell models suffer from technical and biological constraints. Human cell lines might be more useful, but they are much more biohazardous and are often poorly infectible. Here, we describe the human clonal cell line hovS, which lacks the human PRNP gene and expresses instead the ovine PRNP VRQ allele. HovS cells were highly susceptible to the PG127 strain of sheep-derived murine prions, reaching up to 90% infected cells in any given culture and were maintained in a continuous infected state for at least 14 passages. Infected hovS cells produced proteinase K–resistant prion protein (PrPSc), pelletable PrP aggregates, and bona fide infectious prions capable of infecting further generations of naïve hovS cells and mice expressing the VRQ allelic variant of ovine PrPC. Infection in hovS led to prominent cytopathic vacuolation akin to the spongiform changes observed in individuals suffering from prion diseases. In addition to expanding the toolbox for prion research to human experimental genetics, the hovS cell line provides a human-derived system that does not require human prions. Hence, the manipulation of scrapie-infected hovS cells may present fewer biosafety hazards than that of genuine human prions.
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Affiliation(s)
- Merve Avar
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Daniel Heinzer
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Nicolas Steinke
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Berre Doğançay
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Rita Moos
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Severine Lugan
- UMR INRA/ENVT 1225 IHAP, École Nationale Vétérinaire de Toulouse (ENVT), Toulouse, France
| | - Claudia Cosenza
- UMR INRA/ENVT 1225 IHAP, École Nationale Vétérinaire de Toulouse (ENVT), Toulouse, France
| | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Olivier Andréoletti
- UMR INRA/ENVT 1225 IHAP, École Nationale Vétérinaire de Toulouse (ENVT), Toulouse, France
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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12
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Enhanced detection of prion infectivity from blood by preanalytical enrichment with peptoid-conjugated beads. PLoS One 2019; 14:e0216013. [PMID: 31513666 PMCID: PMC6742390 DOI: 10.1371/journal.pone.0216013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/28/2019] [Indexed: 11/29/2022] Open
Abstract
Prions cause transmissible infectious diseases in humans and animals and have been found to be transmissible by blood transfusion even in the presymptomatic stage. However, the concentration of prions in body fluids such as blood and urine is extremely low; therefore, direct diagnostic tests on such specimens often yield false-negative results. Quantitative preanalytical prion enrichment may significantly improve the sensitivity of prion assays by concentrating trace amounts of prions from large volumes of body fluids. Here, we show that beads conjugated to positively charged peptoids not only captured PrP aggregates from plasma of prion-infected hamsters, but also adsorbed prion infectivity in both the symptomatic and preclinical stages of the disease. Bead absorbed prion infectivity efficiently transmitted disease to transgenic indicator mice. We found that the readout of the peptoid-based misfolded protein assay (MPA) correlates closely with prion infectivity in vivo, thereby validating the MPA as a simple, quantitative, and sensitive surrogate indicator of the presence of prions. The reliable and sensitive detection of prions in plasma will enable a wide variety of applications in basic prion research and diagnostics.
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13
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Abstract
Prion diseases are progressive, incurable and fatal neurodegenerative conditions. The term 'prion' was first nominated to express the revolutionary concept that a protein could be infectious. We now know that prions consist of PrPSc, the pathological aggregated form of the cellular prion protein PrPC. Over the years, the term has been semantically broadened to describe aggregates irrespective of their infectivity, and the prion concept is now being applied, perhaps overenthusiastically, to all neurodegenerative diseases that involve protein aggregation. Indeed, recent studies suggest that prion diseases (PrDs) and protein misfolding disorders (PMDs) share some common disease mechanisms, which could have implications for potential treatments. Nevertheless, the transmissibility of bona fide prions is unique, and PrDs should be considered as distinct from other PMDs.
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Affiliation(s)
- Claudia Scheckel
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland.
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14
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Zhu C, Li Z, Li B, Pfammatter M, Hornemann S, Aguzzi A. Unaltered prion disease in mice lacking developmental endothelial locus-1. Neurobiol Aging 2019; 76:208-213. [PMID: 30743056 DOI: 10.1016/j.neurobiolaging.2019.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 01/02/2019] [Accepted: 01/03/2019] [Indexed: 11/19/2022]
Abstract
Progression of prion diseases is driven by the accumulation of prions in the brain. Ablation of microglia or deletion of the eat-me-signal, milk-fat globule epidermal growth factor VIII (Mfge8), accelerates prion pathogenesis, suggesting that microglia defend the brain by phagocytosing prions. Similar to Mfge8, developmental endothelial locus-1 (Del-1) is a secreted protein that acts as an opsonin bridging phagocytes and apoptotic cells to facilitate phagocytosis. We therefore asked whether Del-1 might play a role in controlling prion pathogenesis. We assessed the anti-inflammatory and phagocytosis-promoting functions of Del-1 in prion disease and determined whether Del-1 complements Mfge8 in prion clearance in mice with a C57BL/6J genetic background. We found that Del-1 deficiency did not change prion disease progression or lesion patterns. In addition, prion clearance and scrapie prion protein deposition were unaltered in Del-1-deficient mice. In addition, prion-induced neuroinflammation was not affected by Del-1 deficiency. We conclude that Del-1 is not a major determinant of prion pathogenesis in this context.
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Affiliation(s)
- Caihong Zhu
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Zhihao Li
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Bei Li
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Manuela Pfammatter
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Simone Hornemann
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland.
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15
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A bispecific immunotweezer prevents soluble PrP oligomers and abolishes prion toxicity. PLoS Pathog 2018; 14:e1007335. [PMID: 30273408 PMCID: PMC6181439 DOI: 10.1371/journal.ppat.1007335] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 10/11/2018] [Accepted: 09/13/2018] [Indexed: 11/28/2022] Open
Abstract
Antibodies to the prion protein, PrP, represent a promising therapeutic approach against prion diseases but the neurotoxicity of certain anti-PrP antibodies has caused concern. Here we describe scPOM-bi, a bispecific antibody designed to function as a molecular prion tweezer. scPOM-bi combines the complementarity-determining regions of the neurotoxic antibody POM1 and the neuroprotective POM2, which bind the globular domain (GD) and flexible tail (FT) respectively. We found that scPOM-bi confers protection to prion-infected organotypic cerebellar slices even when prion pathology is already conspicuous. Moreover, scPOM-bi prevents the formation of soluble oligomers that correlate with neurotoxic PrP species. Simultaneous targeting of both GD and FT was more effective than concomitant treatment with the individual molecules or targeting the tail alone, possibly by preventing the GD from entering a toxic-prone state. We conclude that simultaneous binding of the GD and flexible tail of PrP results in strong protection from prion neurotoxicity and may represent a promising strategy for anti-prion immunotherapy. Antibody immunotherapy is considered a viable strategy against prion disease. We previously showed that antibodies against the so-called globular domain of Prion Protein (PrP) can cause PrP dependent neurotoxicity; this does not happen for antibodies against the flexible tail of PrP, which therefore ought to be preferred for therapy. Here we show that simultaneous targeting of both globular domain and flexible tail by a bispecific, combination of a toxic and a non-toxic antibody, results in stronger protection against prion toxicity, even if the bispecific is administered when prion pathology is already conspicuous. We hypothesize that neurotoxicity arises from binding to specific “toxicity triggering sites” in the globular domain. We designed our bispecific with two aims: i) occupying one such site and preventing prion or other factors from docking to it and ii) binding to the flexible tail to engage the region of PrP necessary for neurotoxicity. We also show that neurotoxic antibodies cause the formation of soluble PrP oligomers that cause toxicity on PrP expressing cell lines; these are not formed in the presence of prion protective antibodies. We suggest that these soluble species might play a role in prion toxicity, similarly to what is generally agreed to happen in other neurodegenerative disorders.
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Intrinsic Toxicity of Antibodies to the Globular Domain of the Prion Protein. Biol Psychiatry 2018; 84:e51-e52. [PMID: 29752074 DOI: 10.1016/j.biopsych.2018.01.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 11/24/2022]
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17
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Baral PK, Swayampakula M, Aguzzi A, James MNG. Structural characterization of
POM
6 Fab and mouse prion protein complex identifies key regions for prions conformational conversion. FEBS J 2018; 285:1701-1714. [DOI: 10.1111/febs.14438] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 02/02/2018] [Accepted: 03/16/2018] [Indexed: 12/23/2022]
Affiliation(s)
- Pravas Kumar Baral
- Department of Biochemistry Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
| | - Mridula Swayampakula
- Department of Biochemistry Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
| | - Adriano Aguzzi
- Institute of Neuropathology University of Zurich Switzerland
| | - Michael N. G. James
- Department of Biochemistry Faculty of Medicine and Dentistry University of Alberta Edmonton Canada
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Abstract
Three decades after the discovery of prions as the cause of Creutzfeldt-Jakob disease and other transmissible spongiform encephalopathies, we are still nowhere close to finding an effective therapy. Numerous pharmacological interventions have attempted to target various stages of disease progression, yet none has significantly ameliorated the course of disease. We still lack a mechanistic understanding of how the prions damage the brain, and this situation results in a dearth of validated pharmacological targets. In this review, we discuss the attempts to interfere with the replication of prions and to enhance their clearance. We also trace some of the possibilities to identify novel targets that may arise with increasing insights into prion biology.
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Affiliation(s)
- Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland;
| | - Asvin K K Lakkaraju
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland;
| | - Karl Frontzek
- Institute of Neuropathology, University of Zurich, CH-8091 Zürich, Switzerland;
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