1
|
Everest DJ, Waterhouse S, Kelly T, Velo-Rego E, Sauer MJ. Effectiveness of Capillary Electrophoresis Fluoroimniunoassay of Blood PrPSc for Evaluation of Scrapie Pathogenesis in Sheep. J Vet Diagn Invest 2016; 19:552-7. [PMID: 17823402 DOI: 10.1177/104063870701900516] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Management of prion diseases in livestock would benefit greatly from availability of a validated blood test. A promising immunocapillary electrophoresis technique (also known as capillary electrophoresis fluoroimmunoassay) to detect abnormal prion protein in blood from live sheep is evaluated here. Capillary electrophoresis fluoroimmunoassay was applied to analysis of extracted blood from scrapie-exposed sheep ( n = 87; 347 samples) at various stages of incubation, and to control sheep ( n = 194; 489 samples). Overall, test values for the control and test populations were not significantly different, and a similar proportion of control (7%) and test (10%) sheep were classified as positive. Over 2−3 month intervals from birth until clinical disease, test specificity and sensitivity ranged from 66.7% to 100% and 0% to 66.7%, respectively, indicating poor diagnostic performance at all stages of pathogenesis. In routine application, in its present form, the capillary electrophoresis fluoroimmunoassay procedure proved to be insufficiently robust for use as a blood test for scrapie diagnosis.
Collapse
Affiliation(s)
- David J Everest
- Molecular Pathogenesis and Genetics Department, Veterinary Laboratories Agency (VLA-Weybridge), Addlestone, Surrey, UK
| | | | | | | | | |
Collapse
|
2
|
Identification of misfolded proteins in body fluids for the diagnosis of prion diseases. Int J Cell Biol 2013; 2013:839329. [PMID: 24027585 PMCID: PMC3763259 DOI: 10.1155/2013/839329] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 12/27/2022] Open
Abstract
Transmissible spongiform encephalopathy (TSE) or prion diseases are fatal rare neurodegenerative disorders affecting man and animals and caused by a transmissible infectious agent. TSE diseases are characterized by spongiform brain lesions with neuronal loss and the abnormal deposition in the CNS, and to less extent in other tissues, of an insoluble and protease resistant form of the cellular prion protein (PrPC), named PrPTSE. In man, TSE diseases affect usually people over 60 years of age with no evident disease-associated risk factors. In some cases, however, TSE diseases are unequivocally linked to infectious episodes related to the use of prion-contaminated medicines, medical devices, or meat products as in the variant Creutzfeldt-Jakob disease (CJD). Clinical signs occur months or years after infection, and during this silent period PrPTSE, the only reliable marker of infection, is not easily measurable in blood or other accessible tissues or body fluids causing public health concerns. To overcome the limit of PrPTSE detection, several highly sensitive assays have been developed, but attempts to apply these techniques to blood of infected hosts have been unsuccessful or not yet validated. An update on the latest advances for the detection of misfolded prion protein in body fluids is provided.
Collapse
|
3
|
Matveeva EG, Rudolph A, Moll JR, Thompson RB. Structure-selective anisotropy assay for amyloid Beta oligomers. ACS Chem Neurosci 2012. [PMID: 23181170 DOI: 10.1021/cn3001262] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Amyloid β (Abeta) peptides in their oligomeric form have been proposed as major toxic species in Alzheimer's disease (AD). There are a limited number of anti-Abeta antibodies specific to oligomeric forms of Abeta compared to the monomeric form, and accurate measurement of oligomeric forms in biological samples, cerebrospinal fluid (CSF), or brain extracts remains challenging. We introduce an oligomer-specific (in preference to monomers or fibrils) fluorescence assay based on a conformationally sensitive bis-pyrene-labeled peptide that contains amino acid residues 16-35 of the human amyloid beta protein (pronucleon peptide, PP). This peptide exhibits a shift in fluorescence emission from pyrene excimer to pyrene monomer emission resulting from a conformational change. Specific binding of PP to oligomeric forms of Abeta can be monitored in solution by a change in fluorescence spectrum as well as a change in pyrene monomer fluorescence anisotropy (or polarization). The mechanism of binding and its relation to anisotropy and fluorescence lifetime changes are discussed. The development of a simple, rapid, anisotropy assay for measurement of Abeta oligomers is important for further study of the oligomers' role in AD, and specific detection of oligomers in biological samples, such as cerebrospinal fluid.
Collapse
Affiliation(s)
- Evgenia G. Matveeva
- University of Maryland School of Medicine, Department of Biochemistry and Molecular
Biology, Baltimore, Maryland 21201, United States
- Adlyfe, Inc., Rockville,
Maryland 20850, United States
| | - Alan Rudolph
- Adlyfe, Inc., Rockville,
Maryland 20850, United States
| | | | - Richard B. Thompson
- University of Maryland School of Medicine, Department of Biochemistry and Molecular
Biology, Baltimore, Maryland 21201, United States
| |
Collapse
|
4
|
Hedlin P, Taschuk R, Potter A, Griebel P, Napper S. Detection and control of prion diseases in food animals. ISRN VETERINARY SCIENCE 2012; 2012:254739. [PMID: 23738120 PMCID: PMC3658581 DOI: 10.5402/2012/254739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 12/22/2011] [Indexed: 12/14/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs), or prion diseases, represent a unique form of infectious disease based on misfolding of a self-protein (PrPC) into a pathological, infectious conformation (PrPSc). Prion diseases of food animals gained notoriety during the bovine spongiform encephalopathy (BSE) outbreak of the 1980s. In particular, disease transmission to humans, to the generation of a fatal, untreatable disease, elevated the perspective on livestock prion diseases from food production to food safety. While the immediate threat posed by BSE has been successfully addressed through surveillance and improved management practices, another prion disease is rapidly spreading. Chronic wasting disease (CWD), a prion disease of cervids, has been confirmed in wild and captive populations with devastating impact on the farmed cervid industries. Furthermore, the unabated spread of this disease through wild populations threatens a natural resource that is a source of considerable economic benefit and national pride. In a worst-case scenario, CWD may represent a zoonotic threat either through direct transmission via consumption of infected cervids or through a secondary food animal, such as cattle. This has energized efforts to understand prion diseases as well as to develop tools for disease detection, prevention, and management. Progress in each of these areas is discussed.
Collapse
Affiliation(s)
- Peter Hedlin
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E3 ; Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E3
| | | | | | | | | |
Collapse
|
5
|
Wagoner VA, Cheon M, Chang I, Hall CK. Computer simulation study of amyloid fibril formation by palindromic sequences in prion peptides. Proteins 2011; 79:2132-45. [PMID: 21557317 DOI: 10.1002/prot.23034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 01/26/2011] [Accepted: 02/11/2011] [Indexed: 11/11/2022]
Abstract
We simulate the aggregation of large systems containing palindromic peptides from the Syrian hamster prion protein SHaPrP 113-120 (AGAAAAGA) and the mouse prion protein MoPrP 111-120 (VAGAAAAGAV) and eight sequence variations: GAAAAAAG, (AG)(4) , A8, GAAAGAAA, A10, V10, GAVAAAAVAG, and VAVAAAAVAV The first two peptides are thought to act as the Velcro that holds the parent prion proteins together in amyloid structures and can form fibrils themselves. Kinetic events along the fibrillization pathway influence the types of structures that occur and variations in the sequence affect aggregation kinetics and fibrillar structure. Discontinuous molecular dynamics simulations using the PRIME20 force field are performed on systems containing 48 peptides starting from a random coil configuration. Depending on the sequence, fibrillar structures form spontaneously over a range of temperatures, below which amorphous aggregates form and above which no aggregation occurs. AGAAAAGA forms well organized fibrillar structures whereas VAGAAAAGAV forms less well organized structures that are partially fibrillar and partially amorphous. The degree of order in the fibrillar structure stems in part from the types of kinetic events leading up to its formation, with AGAAAAGA forming less amorphous structures early in the simulation than VAGAAAAGAV. The ability to form fibrils increases as the chain length and the length of the stretch of hydrophobic residues increase. However as the hydrophobicity of the sequence increases, the ability to form well-ordered structures decreases. Thus, longer hydrophobic sequences form slightly disordered aggregates that are partially fibrillar and partially amorphous. Subtle changes in sequence result in slightly different fibril structures.
Collapse
Affiliation(s)
- Victoria A Wagoner
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | | | | | | |
Collapse
|
6
|
Turner ML, Ludlam CA. An update on the assessment and management of the risk of transmission of variant Creutzfeldt-Jakob disease by blood and plasma products. Br J Haematol 2009; 144:14-23. [DOI: 10.1111/j.1365-2141.2008.07376.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
7
|
Grassi J, Maillet S, Simon S, Morel N. Progress and limits of TSE diagnostic tools. Vet Res 2008; 39:33. [PMID: 18284910 DOI: 10.1051/vetres:2008009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 02/05/2008] [Indexed: 11/14/2022] Open
Abstract
Following the two "mad cow" crises of 1996 and 2000, there was an urgent need for rapid and sensitive diagnostic methods to identify animals infected with the bovine spongiform encephalopathy (BSE) agent. This stimulated research in the field of prion diagnosis and led to the establishment of numerous so-called "rapid tests" which have been in use in Europe since 2001 for monitoring at-risk populations (rendering plants) and animals slaughtered for human consumption (slaughterhouse). These rapid tests have played a critical role in the management of the mad cow crisis by allowing the removal of prion infected carcasses from the human food chain, and by allowing a precise epidemiological monitoring of the BSE epizootic. They are all based on the detection of the abnormal form of the prion protein (PrP(Sc) or PrP(res)) in brain tissues and consequently are only suitable for post-mortem diagnosis. Since it is now very clear that variant Creutzfeldt-Jakob disease (vCJD) can be transmitted by blood transfusion, the development of a blood test for the diagnosis of vCJD is a top priority. Although significant progress has been made in this direction, including the development of the protein misfolding cyclic amplification (PMCA) technology, at the time this paper was written, this objective had not yet been achieved. This is the most important challenge for the years to come in this field of prion research.
Collapse
Affiliation(s)
- Jacques Grassi
- Service de Pharmacologie et d'Immunoanalyse, 91191 Gif-sur-Yvette, France.
| | | | | | | |
Collapse
|
8
|
Pan T, Sethi J, Nelsen C, Rudolph A, Cervenakova L, Brown P, Orser CS. Detection of misfolded prion protein in blood with conformationally sensitive peptides. Transfusion 2007; 47:1418-25. [PMID: 17655586 DOI: 10.1111/j.1537-2995.2007.01284.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The long-standing goal of a preclinical diagnostic test for transmissible spongiform encephalopathy (TSE) has recently become urgent because of the discovery that humans with variant Creutzfeldt-Jakob disease can transmit disease via blood transfusions. STUDY DESIGN AND METHODS The misfolded protein diagnostic (MPD) assay employs a pyrene-labeled palindromic sequence of prion peptides that undergoes a cascade of coil to beta-sheet conversion in the presence of the misfolded prion protein (PrP(TSE)). The ability of the assay to detect PrP(TSE) in brain, serum, and plasma was tested. The basic protocol involved a several-hour incubation of 200-microL sample volumes with the peptide reagent in 96-well plates, after which fluorescence was monitored by a fluorescence plate reader with an excitation wavelength of 350 nm and emission scanning wavelength range of 365 to 600 nm. RESULTS Target specificity for PrP(TSE) was documented by correlation of assay signal with Western blot signals in brain tissue from TSE-infected, normal, and knockout mice and negative assay signals by use of reagents with different peptide sequences. When applied to plasma or serum, the assay discriminated between samples from a variety of experimental and natural TSE infections compared to uninfected controls, with a sensitivity threshold of approximately 1 infectious dose per mL in pooled plasma from TSE-infected mice. CONCLUSIONS The MPD assay is a sensitive and specific test for the detection of PrP(TSE) that may be useful in both preclinical and clinical diagnosis of TSE diseases of animals and humans.
Collapse
Affiliation(s)
- Tao Pan
- Adlyfe Inc., 9430 Key West Avenue, Rockville, MD 20850, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Flan B, Arrabal S. Manufacture of plasma-derived products in France and measures to prevent the risk of vCJD transmission: Precautionary measures and efficacy of manufacturing processes in prion removal. Transfus Clin Biol 2007; 14:51-62. [PMID: 17540602 DOI: 10.1016/j.tracli.2007.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The emergence of the variant Creutzfeldt-Jakob disease in the mid 1990s soon raised concerns about its possible transmission through the use of blood and plasma-derived medicinal products. A risk analysis approach was initiated by health authorities, based on updated scientific knowledge and precautionary measures were implemented in France and other countries for the management of this new possible risk. Assessment of the vCJD risk is based on epidemiology and estimates of the number of potential cases in the future, on blood infectivity data from models of transmissible spongiform encephalopathies and on data from studies of the capacity of manufacturing processes to remove the agent, should it be present in the plasma of infected donors. The transmission of vCJD by non leukocyte-depleted labile blood components has recently been confirmed. There have been no reports of cases associated with the use of plasma-derived products and the scientific data, and risk analyses for those plasma products, which are of the greatest therapeutic interest, support their safety with respect to this transmission risk. The precautionary measures applied in France and the data contributing to the risk assessment of plasma products are reviewed and updated in the present paper. The uncertainties, which remain, are also addressed and discussed, as well as the ongoing research and developments in this area.
Collapse
Affiliation(s)
- Benoît Flan
- LFB S.A., 3 avenue des Tropiques, B.P. 305 Les Ulis, 91958 Courtaboeuf cedex, France.
| | | |
Collapse
|
10
|
Lehto MT, Peery HE, Cashman NR. Current and future molecular diagnostics for prion diseases. Expert Rev Mol Diagn 2006; 6:597-611. [PMID: 16824033 DOI: 10.1586/14737159.6.4.597] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is now widely held that the infectious agents underlying the transmissible spongiform encephalopathies are prions, which are primarily composed of a misfolded, protease-resistant isoform of the host prion protein. Untreatable prion disorders include some human diseases, such as Creutzfeldt-Jakob disease, and diseases of economically important animals, such as bovine spongiform encephalopathy (cattle) and chronic wasting disease (deer and elk). Detection and diagnosis of prion disease (and presymptomatic incubation) is contingent upon developing novel assays, which exploit properties uniquely possessed by this misfolded protein complex, rather than targeting an agent-specific nucleic acid. This review highlights some of the conventional and disruptive technologies developed to respond to this challenge.
Collapse
Affiliation(s)
- Marty T Lehto
- Amorfix Life Sciences, 3080 Yonge Street, Suite 6020, Toronto, M4N 3N1, Canada.
| | | | | |
Collapse
|
11
|
Lourenco PC, Schmerr MJ, MacGregor I, Will RG, Ironside JW, Head MW. Application of an immunocapillary electrophoresis assay to the detection of abnormal prion protein in brain, spleen and blood specimens from patients with variant Creutzfeldt–Jakob disease. J Gen Virol 2006; 87:3119-3124. [PMID: 16963772 DOI: 10.1099/vir.0.81935-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sensitive and specific detection of abnormal prion protein in blood could provide a diagnostic test or screening assay for animal and human prion diseases. Here, the application of an immunocapillary electrophoresis (ICE) method developed for sheep scrapie to brain, spleen and blood from patients with Creutzfeldt–Jakob disease (CJD) is described. The assay involves organic-solvent extraction, a competitive immunoassay using fluorescently labelled synthetic prion protein peptides and polyclonal antibodies specific for those sequences, and analysis by capillary electrophoresis using laser-induced fluorescence detection. The test was evaluated by using clinical blood specimens from patients with variant (n=5) or sporadic (n=4) CJD and patients initially suspected of having CJD who were given an alternative diagnosis (n=6). In this context, the ICE assay was specific, but incompletely sensitive (55 %). The method was unable to detect abnormal prion protein in variant CJD brain or spleen reference materials due to its loss during the extraction process.
Collapse
Affiliation(s)
- Paula C Lourenco
- National CJD Surveillance Unit, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Mary Jo Schmerr
- Ames Laboratory, USDOE, Iowa State University, Ames, IA 500011, USA
| | - Ian MacGregor
- SNBTS Products and Components R&D Group, National Science Laboratory, 21 Ellen's Glen Road, Edinburgh EH17 7QT, UK
| | - Robert G Will
- National CJD Surveillance Unit, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - James W Ironside
- National CJD Surveillance Unit, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Mark W Head
- National CJD Surveillance Unit, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| |
Collapse
|