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Stanley B. Prusiner - One of the best experts on this subject based on the ideXlab platform.
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Prions.
Cold Spring Harbor perspectives in biology, 2011Co-Authors: David W Colby, Stanley B. PrusinerAbstract:The discovery of infectious proteins, denoted Prions, was unexpected. After much debate over the chemical basis of heredity, resolution of this issue began with the discovery that DNA, not protein, from pneumococcus was capable of genetically transforming bacteria (Avery et al. 1944). Four decades later, the discovery that a protein could mimic viral and bacterial pathogens with respect to the transmission of some nervous system diseases (Prusiner 1982) met with great resistance. Overwhelming evidence now shows that Creutzfeldt-Jakob disease (CJD) and related disorders are caused by Prions. The Prion diseases are characterized by neurodegeneration and lethality. In mammals, Prions reproduce by recruiting the normal, cellular isoform of the Prion protein (PrP(C)) and stimulating its conversion into the disease-causing isoform (PrP(Sc)). PrP(C) and PrP(Sc) have distinct conformations: PrP(C) is rich in α-helical content and has little β-sheet structure, whereas PrP(Sc) has less α-helical content and is rich in β-sheet structure (Pan et al. 1993). The conformational conversion of PrP(C) to PrP(Sc) is the fundamental event underlying Prion diseases. In this article, we provide an introduction to Prions and the diseases they cause.
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Measuring Prions by bioluminescence imaging.
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Kevin P Francis, Kurt Giles, Azucena Lemus, Stephen J. Dearmond, Stanley B. Prusiner, Gültekin TamgüneyAbstract:Prions are infectious proteins that cause fatal neurodegenerative diseases. Because astrocytic gliosis marked by the deposition of fibrils composed of GFAP is a prominent feature of Prion disease, we asked whether GFAP might be used as a surrogate marker for Prions. To interrogate this posit, we inoculated Prions into transgenic (Tg) mice expressing luciferase (luc) under the GFAP gene (Gfap) promoter, denoted Tg(Gfap-luc) mice. Weekly noninvasive, bioluminescence imaging (BLI) detected an increase in light emitted from the brains of Tg(Gfap-luc) mice at approximately 55 d after inoculation and approximately 62 d before neurologic deficits appeared. To determine whether BLI could be used as a proxy bioassay for Prion infectivity, we performed endpoint titrations of Prions in Tg(Gfap-luc) mice. BLI bioassays were as or more sensitive than those determined by the onset of neurological dysfunction, and were completed in approximately half the time. Our studies argue that BLI is likely to be a suitable surrogate for measuring Prion infectivity, and might be useful in the study of Tg mouse models for other neurodegenerative illnesses.
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Prion detection by an amyloid seeding assay
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: David W Colby, Giuseppe Legname, Darlene Groth, Qiang Zhang, Shuyi Wang, Detlev Riesner, Stanley B. PrusinerAbstract:Polymerization of recombinant Prion protein (recPrP), which was produced in bacteria, into amyloid fibers was accompanied by the acquisition of Prion infectivity. We report here that partially purified preparations of Prions seed the polymerization of recPrP into amyloid as detected by a fluorescence shift in the dye Thioflavin T. Our amyloid seeding assay (ASA) detected PrPSc, the sole component of the Prion, in brain samples from humans with sporadic Creutzfeldt–Jakob disease, as well as in rodents with experimental Prion disease. The ASA detected a variety of Prion strains passaged in both mice and hamsters. The sensitivity of the ASA varied with strain type; for hamster Sc237 Prions, the limit of detection was ≈1 fg. Some Prion strains consist largely of protease-sensitive PrPSc (sPrPSc), and these strains were readily detected by ASA. Our studies show that the ASA provides an alternative methodology for detecting both sPrPSc and protease-resistant PrPSc that does not rely on protease digestion or immunodetection.
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Disinfection of Prions
2007Co-Authors: Kurt Giles, Surachai Supattapone, David Peretz, David V. Glidden, Henry Baron, Stanley B. PrusinerAbstract:Prions are unprecedented transmissible pathogenic agents that cause a group of fatal neurodegenerative diseases, including Creutzfeldt-Jakob disease (CJD) and kuru in humans, bovine spongiform encephalopathy (BSE) in cattle, chronic wasting disease (CWD) in deer and elk, and scrapie in sheep and goats. Prions are resistant to standard disinfection and sterilization procedures validated against viruses and bacteria. There are well documented cases of iatrogenic Prion transmission from surgical instruments and cadaveric tissue. The lack of noncorrosive procedures that inactivate Prions is a cause for concern for hospital infection-control departments. A novel method to inactivate human Prions completely, using sodium dodecyl sulfate at acidic pH (acidic SDS), is reported here. Prion inactivation was demonstrated on both brain homogenate and on the surface of contaminated surgical stainless steel, the latter of which proved significantly more resistant to inactivation.
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Thermodynamics of model Prions and its implications for the problem of Prion protein folding
Journal of Molecular Biology, 1999Co-Authors: Paul M. Harrison, Hue Sun Chan, Stanley B. Prusiner, Fred E. CohenAbstract:Prion disease is caused by the propagation of a particle containing PrP(Sc), a misfolded form of the normal cellular Prion protein (PrP(C)). PrP(C) can refold to form PrP(Sc) with loss of α-helical structure and formation of extensive β-sheet structure. Here, we model this Prion folding problem with a simple, low-resolution lattice model of protein folding. If model proteins are allowed to re-fold upon dimerization, a minor proportion of them (up to ~ 17%) encrypts an alternative native state as a homodimer. The structures in this homodimeric native state re-arrange so that they are very different in conformation from the monomeric native state. We find that model proteins that are relatively less stable as monomers are more susceptible to the formation of alternative native states as homodimers. These results suggest that less-stable proteins have a greater need for a well-designed energy landscape for protein folding to overcome an increased chance of encrypting substantially different native conformations stabilized by multimeric interactions. This conceptual framework for aberrant folding should be relevant in Alzheimer's disease and other disorders associated with protein aggregation.
John Collinge - One of the best experts on this subject based on the ideXlab platform.
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Prion diseases.
Journal of neurovirology, 2020Co-Authors: Edward Mckintosh, Sarah J Tabrizi, John CollingeAbstract:Prion diseases are incurable neurodegenerative conditions affecting both animals and humans. They may be sporadic, infectious, or inherited in origin. Human Prion diseases include Creutzfeldt-Jakob desease (CJD), Gerstmann-Straussler-Scheinker disease, kuru, and fatal familial insomnia. The appearance of variant CJD, and the demonstration that is caused by strains indistinguishable from bovine spongiform encephalopathy (BSE) in cattle, has led to the threat of a major epidemic of human Prion disease in the UK and other countries where widespread dietary exposure to bovine Prions has occurred. This article reviews the history and epidemiology of these diseases, and then focuses on important areas of current research in human Prion disorders.
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Prion propagation and toxicity in vivo occur in two distinct mechanistic phases
Nature, 2011Co-Authors: Malin K Sandberg, Huda Aldoujaily, Bernadette Sharps, Anthony R Clarke, John CollingeAbstract:Here it is shown that during the silent phase of Prion infection, Prions first exponentially propagate until a defined limit is reached. Then a plateau phase follows. Prion propagation is independent of Prion concentration, whereas in the plateau phase the time to clinical onset is inversely correlated to Prion concentration. The similar levels of infectivity at the end of the first and second phase suggests that there is a separation between Prion infectivity and toxicity. Moreover, something seems to limit Prion production. It is suggested that the Prions are not neurotoxic themselves but catalyse the formation of such species from PrPC. Production of neurotoxic species is triggered when Prion propagation saturates, leading to a switch from autocatalytic production of infectivity to a toxic pathway.
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Preventing Prion Pathogenicity by Targeting the Cellular Prion Protein
Infectious disorders drug targets, 2009Co-Authors: Andrew J. Nicoll, John CollingeAbstract:Prions are unique in that the infectious particles contain no detectable nucleic acid and appear to consist of aggregated forms of misfolded cellular Prion protein. Prions form distinct strains and can transmit disease between species. Whilst the molecular basis of Prion diseases is beginning to be unravelled, much remains unknown including the atomic structure of the infectious and toxic species. In contrast, the structure and folding properties of the cellular Prion protein are well characterised and, although its precise function remains enigmatic, constitutive knockout of protein expression in mice produces apparently healthy animals but which are fully resistant to Prion infection. Furthermore, recent data show that neuronal knockout of the gene encoding for Prion protein during established brain infection leads to reversal of pathology and behavioural deficits, giving hope that effective therapies could be designed. Stabilising the cellular form of the Prion protein and preventing it from misfolding could be one way to slow or prevent Prion formation. Immunotherapy of peripherally Prion-infected mice with an antibody specific for cellular Prion protein can prevent disease onset. However, a small molecule capable of curing Prion infection in vivo has still to be discovered. Recent work has provided proof of principle that compounds which bind selectively to the cellular Prion protein could act as therapeutics for Prion diseases.
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Prions and the Prion disorders
Mammalian Genome, 1998Co-Authors: Elizabeth M.c. Fisher, Glenn Telling, John CollingeAbstract:One of us remembers sitting in a high school biology class in 1977 being taught about scrapie, a naturally occurring disorder of sheep. The teacher had no particular interest in agriculture, but was pointing out some peculiar characteristics of this disease as a biological curiosity on a wet Friday afternoon. The Prion disorders captured the imagination of a range of biologists (including that teacher) well before the epidemic of bovine spongiform encephalopathy (BSE) and the appearance of a new variant of the human Prion disease, Creutzfeldt Jakob disease (CJD), in the UK, because of their extraordinary biology and the unique properties of the infectious agent. We review the results of studies leading to a convergence of evidence that the causative infectious agent, the `Prion', is devoid of nucleic acid and is composed of an abnormal isoform of a host-encoded protein, the Prion protein (PrP).
Jacqueline M Linehan - One of the best experts on this subject based on the ideXlab platform.
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a naturally occurring variant of the human Prion protein completely prevents Prion disease
Nature, 2015Co-Authors: Emmanuel A Asante, Michelle Smidak, Andrew Grimshaw, Richard Houghton, Andrew Tomlinson, Asif Jeelani, Tatiana Jakubcova, Shyma Hamdan, Angela Richardlondt, Jacqueline M LinehanAbstract:This study looks at a polymorphism of the human Prion protein gene, which results in a G-to-V substitution at residue 127, in transgenic mice expressing different human Prion proteins, finding that mice heterozygous for the G127V polymorphism are resistant to both kuru and classical CJD Prions, but there is some transmission of variant CJD Prions; most remarkable, however, is that mice homozygous for V127 are completely resistant to all Prion strains.
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human Prion protein with valine 129 prevents expression of variant cjd phenotype
Science, 2004Co-Authors: Jonathan D F Wadsworth, Emmanuel A Asante, Jacqueline M Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Julie Welch, Sarah E Lloyd, Lisa Stone, Andrew F. HillAbstract:Variant Creutzfeldt-Jakob disease (vCJD) is a unique and highly distinctive clinicopathological and molecular phenotype of human Prion disease associated with infection with bovine spongiform encephalopathy (BSE)–like Prions. Here, we found that generation of this phenotype in transgenic mice required expression of human Prion protein (PrP) with methionine 129. Expression of human PrP with valine 129 resulted in a distinct phenotype and, remarkably, persistence of a barrier to transmission of BSE-derived Prions on subpassage. Polymorphic residue 129 of human PrP dictated propagation of distinct Prion strains after BSE Prion infection. Thus, primary and secondary human infection with BSE-derived Prions may result in sporadic CJD-like or novel phenotypes in addition to vCJD, depending on the genotype of the Prion source and the recipient.
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bse Prions propagate as either variant cjd like or sporadic cjd like Prion strains in transgenic mice expressing human Prion protein
The EMBO Journal, 2002Co-Authors: Emmanuel A Asante, Andrew F. Hill, Jacqueline M Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L Wood, Julie Welch, Sarah E Lloyd, Jonathan D F WadsworthAbstract:Variant Creutzfeldt–Jakob disease (vCJD) has been recognized to date only in individuals homozygous for methionine at PRNP codon 129. Here we show that transgenic mice expressing human PrP methionine 129, inoculated with either bovine spongiform encephalopathy (BSE) or variant CJD Prions, may develop the neuropathological and molecular phenotype of vCJD, consistent with these diseases being caused by the same Prion strain. Surprisingly, however, BSE transmission to these transgenic mice, in addition to producing a vCJD-like phenotype, can also result in a distinct molecular phenotype that is indistinguishable from that of sporadic CJD with PrPSc type 2. These data suggest that more than one BSE-derived Prion strain might infect humans; it is therefore possible that some patients with a phenotype consistent with sporadic CJD may have a disease arising from BSE exposure.
Emmanuel A Asante - One of the best experts on this subject based on the ideXlab platform.
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a naturally occurring variant of the human Prion protein completely prevents Prion disease
Nature, 2015Co-Authors: Emmanuel A Asante, Michelle Smidak, Andrew Grimshaw, Richard Houghton, Andrew Tomlinson, Asif Jeelani, Tatiana Jakubcova, Shyma Hamdan, Angela Richardlondt, Jacqueline M LinehanAbstract:This study looks at a polymorphism of the human Prion protein gene, which results in a G-to-V substitution at residue 127, in transgenic mice expressing different human Prion proteins, finding that mice heterozygous for the G127V polymorphism are resistant to both kuru and classical CJD Prions, but there is some transmission of variant CJD Prions; most remarkable, however, is that mice homozygous for V127 are completely resistant to all Prion strains.
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human Prion protein with valine 129 prevents expression of variant cjd phenotype
Science, 2004Co-Authors: Jonathan D F Wadsworth, Emmanuel A Asante, Jacqueline M Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Julie Welch, Sarah E Lloyd, Lisa Stone, Andrew F. HillAbstract:Variant Creutzfeldt-Jakob disease (vCJD) is a unique and highly distinctive clinicopathological and molecular phenotype of human Prion disease associated with infection with bovine spongiform encephalopathy (BSE)–like Prions. Here, we found that generation of this phenotype in transgenic mice required expression of human Prion protein (PrP) with methionine 129. Expression of human PrP with valine 129 resulted in a distinct phenotype and, remarkably, persistence of a barrier to transmission of BSE-derived Prions on subpassage. Polymorphic residue 129 of human PrP dictated propagation of distinct Prion strains after BSE Prion infection. Thus, primary and secondary human infection with BSE-derived Prions may result in sporadic CJD-like or novel phenotypes in addition to vCJD, depending on the genotype of the Prion source and the recipient.
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bse Prions propagate as either variant cjd like or sporadic cjd like Prion strains in transgenic mice expressing human Prion protein
The EMBO Journal, 2002Co-Authors: Emmanuel A Asante, Andrew F. Hill, Jacqueline M Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L Wood, Julie Welch, Sarah E Lloyd, Jonathan D F WadsworthAbstract:Variant Creutzfeldt–Jakob disease (vCJD) has been recognized to date only in individuals homozygous for methionine at PRNP codon 129. Here we show that transgenic mice expressing human PrP methionine 129, inoculated with either bovine spongiform encephalopathy (BSE) or variant CJD Prions, may develop the neuropathological and molecular phenotype of vCJD, consistent with these diseases being caused by the same Prion strain. Surprisingly, however, BSE transmission to these transgenic mice, in addition to producing a vCJD-like phenotype, can also result in a distinct molecular phenotype that is indistinguishable from that of sporadic CJD with PrPSc type 2. These data suggest that more than one BSE-derived Prion strain might infect humans; it is therefore possible that some patients with a phenotype consistent with sporadic CJD may have a disease arising from BSE exposure.
Byron Caughey - One of the best experts on this subject based on the ideXlab platform.
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Novel strain properties distinguishing sporadic Prion diseases sharing Prion protein genotype and Prion type
Scientific Reports, 2017Co-Authors: Laura Cracco, Bernardino Ghetti, Silvio Notari, Ignazio Cali, Man Sun Sy, Shu G. Chen, Mark L. Cohen, Brian S. Appleby, Byron CaugheyAbstract:Novel strain properties distinguishing sporadic Prion diseases sharing Prion protein genotype and Prion type
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Host Determinants of Prion Strain Diversity Independent of Prion Protein Genotype
Journal of Virology, 2015Co-Authors: Jenna A.e. Crowell, Byron Caughey, Andrew G Hughson, Richard A. BessenAbstract:ABSTRACT Phenotypic diversity in Prion diseases can be specified by Prion strains in which biological traits are propagated through an epigenetic mechanism mediated by distinct PrP Sc conformations. We investigated the role of host-dependent factors on phenotypic diversity of chronic wasting disease (CWD) in different host species that express the same Prion protein gene ( Prnp ). Two CWD strains that have distinct biological, biochemical, and pathological features were identified in transgenic mice that express the Syrian golden hamster (SGH) Prnp . The CKY strain of CWD had a shorter incubation period than the WST strain of CWD, but after transmission to SGH, the incubation period of CKY CWD was ∼150 days longer than WST CWD. Limited proteinase K digestion revealed strain-specific PrP Sc polypeptide patterns that were maintained in both hosts, but the solubility and conformational stability of PrP Sc differed for the CWD strains in a host-dependent manner. WST CWD produced PrP Sc amyloid plaques in the brain of the SGH that were partially insoluble and stable at a high concentration of protein denaturant. However, in transgenic mice, PrP Sc from WST CWD did not assemble into plaques, was highly soluble, and had low conformational stability. Similar studies using the HY and DY strains of transmissible mink encephalopathy resulted in minor differences in Prion biological and PrP Sc properties between transgenic mice and SGH. These findings indicate that host-specific pathways that are independent of Prnp can alter the PrP Sc conformation of certain Prion strains, leading to changes in the biophysical properties of PrP Sc , neuropathology, and clinical Prion disease. IMPORTANCE Prions are misfolded pathogenic proteins that cause neurodegeneration in humans and animals. Transmissible Prion diseases exhibit a spectrum of disease phenotypes and the basis of this diversity is encoded in the structure of the pathogenic Prion protein and propagated by an epigenetic mechanism. In the present study, we investigated Prion diversity in two hosts species that express the same Prion protein gene. While prior reports have demonstrated that Prion strain properties are stable upon infection of the same host species and Prion protein genotype, our findings indicate that certain Prion strains can undergo dramatic changes in biological properties that are not dependent on the Prion protein. Therefore, host factors independent of the Prion protein can affect Prion diversity. Understanding how host pathways can modify Prion disease phenotypes may provide clues on how to alter Prion formation and lead to treatments for Prion, and other, human neurodegenerative diseases of protein misfolding.
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bank vole Prion protein as an apparently universal substrate for rt quic based detection and discrimination of Prion strains
PLOS Pathogens, 2015Co-Authors: Christina D Orru, Pierluigi Gambetti, Lynne D Raymond, Bradley R Groveman, Andrew G Hughson, Romolo Nonno, Bernardino Ghetti, Byron CaugheyAbstract:Prions propagate as multiple strains in a wide variety of mammalian species. The detection of all such strains by a single ultrasensitive assay such as Real Time Quaking-induced Conversion (RT-QuIC) would facilitate Prion disease diagnosis, surveillance and research. Previous studies have shown that bank voles, and transgenic mice expressing bank vole Prion protein, are susceptible to most, if not all, types of Prions. Here we show that bacterially expressed recombinant bank vole Prion protein (residues 23-230) is an effective substrate for the sensitive RT-QuIC detection of all of the different Prion types that we have tested so far – a total of 28 from humans, cattle, sheep, cervids and rodents, including several that have previously been undetectable by RT-QuIC or Protein Misfolding Cyclic Amplification. Furthermore, comparison of the relative abilities of different Prions to seed positive RT-QuIC reactions with bank vole and not other recombinant Prion proteins allowed discrimination of Prion strains such as classical and atypical L-type bovine spongiform encephalopathy, classical and atypical Nor98 scrapie in sheep, and sporadic and variant Creutzfeldt-Jakob disease in humans. Comparison of protease-resistant RT-QuIC conversion products also aided strain discrimination and suggested the existence of several distinct classes of Prion templates among the many strains tested.
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Prion disease blood test using immunoprecipitation and improved quaking induced conversion
Mbio, 2011Co-Authors: Christina D Orru, Alex J. Raeber, Jason M Wilham, Lynne D Raymond, Franziska Kuhn, Bjorn Schroeder, Byron CaugheyAbstract:ABSTRACT A key challenge in managing transmissible spongiform encephalopathies (TSEs) or Prion diseases in medicine, agriculture, and wildlife biology is the development of practical tests for Prions that are at or below infectious levels. Of particular interest are tests capable of detecting Prions in blood components such as plasma, but blood typically has extremely low Prion concentrations and contains inhibitors of the most sensitive Prion tests. One of the latter tests is quaking-induced conversion (QuIC), which can be as sensitive as in vivo bioassays, but much more rapid, higher throughput, and less expensive. Now we have integrated antibody 15B3-based immunoprecipitation with QuIC reactions to increase sensitivity and isolate Prions from inhibitors such as those in plasma samples. Coupling of immunoprecipitation and an improved real-time QuIC reaction dramatically enhanced detection of variant Creutzfeldt-Jakob disease (vCJD) brain tissue diluted into human plasma. Dilutions of 10 14 -fold, containing ~2 attogram (ag) per ml of proteinase K-resistant Prion protein, were readily detected, indicating ~10,000-fold greater sensitivity for vCJD brain than has previously been reported. We also discriminated between plasma and serum samples from scrapie-infected and uninfected hamsters, even in early preclinical stages. This combined assay, which we call “enhanced QuIC” (eQuIC), markedly improves prospects for routine detection of low levels of Prions in tissues, fluids, or environmental samples. IMPORTANCE Transmissible spongiform encephalopathies (TSEs) are largely untreatable and are difficult to diagnose definitively prior to irreversible clinical decline or death. The transmissibility of TSEs within and between species highlights the need for practical tests for even the smallest amounts of infectivity. A few sufficiently sensitive in vitro methods have been reported, but most have major limitations that would preclude their use in routine diagnostic or screening applications. Our new assay improves the outlook for such critical applications. We focused initially on blood plasma because a practical blood test for Prions would be especially valuable for TSE diagnostics and risk reduction. Variant Creutzfeldt-Jakob disease (vCJD) in particular has been transmitted between humans via blood transfusions. Enhanced real-time quaking-induced conversion (eRTQ) provides by far the most sensitive detection of vCJD to date. The 15B3 antibody binds Prions of multiple species, suggesting that our assay may be useful for clinical and fundamental studies of a variety of TSEs of humans and animals.
