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Koshy SM, Kincaid AE, Bartz JC. Transport of Prions in the Peripheral Nervous System: Pathways, Cell Types, and Mechanisms. Viruses 2022; 14:630. [PMID: 35337037 PMCID: PMC8954800 DOI: 10.3390/v14030630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 01/27/2023] Open
Abstract
Prion diseases are transmissible protein misfolding disorders that occur in animals and humans where the endogenous prion protein, PrPC, undergoes a conformational change into self-templating aggregates termed PrPSc. Formation of PrPSc in the central nervous system (CNS) leads to gliosis, spongiosis, and cellular dysfunction that ultimately results in the death of the host. The spread of prions from peripheral inoculation sites to CNS structures occurs through neuroanatomical networks. While it has been established that endogenous PrPC is necessary for prion formation, and that the rate of prion spread is consistent with slow axonal transport, the mechanistic details of PrPSc transport remain elusive. Current research endeavors are primarily focused on the cellular mechanisms of prion transport associated with axons. This includes elucidating specific cell types involved, subcellular machinery, and potential cofactors present during this process.
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Affiliation(s)
- Sam M. Koshy
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE 68178, USA;
| | - Anthony E. Kincaid
- Department of Pharmacy Science, School of Pharmacy and Health Professions, Creighton University, Omaha, NE 68178, USA;
| | - Jason C. Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE 68178, USA;
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2
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Bartz JC. Environmental and host factors that contribute to prion strain evolution. Acta Neuropathol 2021; 142:5-16. [PMID: 33899132 PMCID: PMC8932343 DOI: 10.1007/s00401-021-02310-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 02/08/2023]
Abstract
Prions are novel pathogens that are composed entirely of PrPSc, the self-templating conformation of the host prion protein, PrPC. Prion strains are operationally defined as a heritable phenotype of disease that are encoded by strain-specific conformations of PrPSc. The factors that influence the relative distribution of strains in a population are only beginning to be understood. For prions with an infectious etiology, environmental factors, such as strain-specific binding to surfaces and resistance to weathering, can influence which strains are available for transmission to a naïve host. Strain-specific differences in efficiency of infection by natural routes of infection can also select for prion strains. The host amino acid sequence of PrPC has the greatest effect on dictating the repertoire of prion strains. The relative abundance of PrPC, post-translational modifications of PrPC and cellular co-factors involved in prion conversion can also provide conditions that favor the prevalence of a subset of prion strains. Additionally, prion strains can interfere with each other, influencing the emergence of a dominant strain. Overall, both environmental and host factors may influence the repertoire and distribution of strains within a population.
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Affiliation(s)
- Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA.
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3
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Kuznetsova A, McKenzie D, Cullingham C, Aiken JM. Long-Term Incubation PrP CWD with Soils Affects Prion Recovery but Not Infectivity. Pathogens 2020; 9:pathogens9040311. [PMID: 32340296 PMCID: PMC7238116 DOI: 10.3390/pathogens9040311] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 01/12/2023] Open
Abstract
Chronic wasting disease (CWD) is a contagious prion disease of cervids. The infectious agent is shed from animals at the preclinical and clinical stages of disease where it persists in the environment as a reservoir of CWD infectivity. In this study, we demonstrate that long-term incubation of CWD prions (generated from tg-mice infected with deer or elk prions) with illite, montmorillonite (Mte) and whole soils results in decreased recovery of PrPCWD, suggesting that binding becomes more avid and irreversible with time. This continual decline of immunoblot PrPCWD detection did not correlate with prion infectivity levels. Bioassay showed no significant differences in incubation periods between mice inoculated with 1% CWD brain homogenate (BH) and with the CWD-BH pre-incubated with quartz or Luvisolic Ae horizon for 1 or 30 weeks. After 55 weeks incubation with Chernozem and Luvisol, bound PrPCWD was not detectable by immunoblotting but remained infectious. This study shows that although recovery of PrPCWD bound to soil minerals and whole soils with time become more difficult, prion infectivity is not significantly altered. Detection of prions in soil is, therefore, not only affected by soil type but also by length of time of the prion–soil interaction.
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Affiliation(s)
- Alsu Kuznetsova
- Agricultural, Life and Environmental Sciences Faculty, University of Alberta, Edmonton, AB T6G 2G8, Canada;
| | - Debbie McKenzie
- Faculty of Science, University of Alberta, Edmonton, AB T6G 2M8, Canada;
| | | | - Judd M. Aiken
- Agricultural, Life and Environmental Sciences Faculty, University of Alberta, Edmonton, AB T6G 2G8, Canada;
- Correspondence:
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Dehydration of Prions on Environmentally Relevant Surfaces Protects Them from Inactivation by Freezing and Thawing. J Virol 2018; 92:JVI.02191-17. [PMID: 29386284 DOI: 10.1128/jvi.02191-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 01/24/2018] [Indexed: 11/20/2022] Open
Abstract
Chronic wasting disease (CWD) is an emerging prion disease in North America. Recent identification of CWD in wild cervids from Norway raises the concern of the spread of CWD in Europe. CWD infectivity can enter the environment through live animal excreta and carcasses where it can bind to soil. Well-characterized hamster prion strains and CWD field isolates in unadsorbed or soil-adsorbed forms that were either hydrated or dehydrated were subjected to repeated rounds of freezing and thawing. We found that 500 cycles of repeated freezing and thawing of hydrated samples significantly decreased the abundance of PrPSc and reduced protein misfolding cyclic amplification (PMCA) seeding activity that could be rescued by binding to soil. Importantly, dehydration prior to freezing and thawing treatment largely protected PrPSc from degradation, and the samples maintained PMCA seeding activity. We hypothesize that redistribution of water molecules during the freezing and thawing process alters the stability of PrPSc aggregates. Overall, these results have significant implications for the assessment of prion persistence in the environment.IMPORTANCE Prions excreted into the environment by infected animals, such as elk and deer infected with chronic wasting disease, persist for years and thus facilitate horizontal transmission of the disease. Understanding the fate of prions in the environment is essential to control prion disease transmission. The significance of our study is that it provides information on the possibility of prion degradation and inactivation under natural weathering processes. This information is significant for remediation of prion-contaminated environments and development of prion disease control strategies.
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Henderson DM, Tennant JM, Haley NJ, Denkers ND, Mathiason CK, Hoover EA. Detection of chronic wasting disease prion seeding activity in deer and elk feces by real-time quaking-induced conversion. J Gen Virol 2017; 98:1953-1962. [PMID: 28703697 DOI: 10.1099/jgv.0.000844] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chronic wasting disease (CWD) is an emergent prion disease affecting cervid species in North America, Canada, South Korea, and recently, Norway. Detection of CWD has been advanced by techniques that rely on amplification of low levels of prion amyloid to a detectable level. However, the increased sensitivity of amplification assays is often compromised by inhibitors and/or activators in complex biologic samples including body fluids, excreta, or the environment. Here, we adapt real-time quaking-induced conversion conditions to specifically detect CWD prions in fecal samples from both experimentally infected deer and naturally infected elk and estimate environmental contamination. The results have application to detection, surveillance and management of CWD, and potentially to other protein-misfolding diseases.
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Affiliation(s)
- Davin M Henderson
- Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Joanne M Tennant
- Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Nicholas J Haley
- Department of Microbiology and Pathology, Midwestern State University, Glendale, AZ, USA
| | - Nathaniel D Denkers
- Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Candace K Mathiason
- Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Edward A Hoover
- Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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Tyshenko MG, Oraby T, Darshan S, Westphal M, Croteau MC, Aspinall W, Elsaadany S, Krewski D, Cashman N. Expert elicitation on the uncertainties associated with chronic wasting disease. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:729-745. [PMID: 27556566 DOI: 10.1080/15287394.2016.1174007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A high degree of uncertainty exists for chronic wasting disease (CWD) transmission factors in farmed and wild cervids. Evaluating the factors is important as it helps to inform future risk management strategies. Expert opinion is often used to assist decision making in a number of health, science, and technology domains where data may be sparse or missing. Using the "Classical Model" of elicitation, a group of experts was asked to estimate the most likely values for several risk factors affecting CWD transmission. The formalized expert elicitation helped structure the issues and hence provide a rational basis for estimating some transmission risk factors for which evidence is lacking. Considered judgments regarding environmental transmission, latency of CWD transmission, management, and species barrier were provided by the experts. Uncertainties for many items were determined to be large, highlighting areas requiring more research. The elicited values may be used as surrogate values until research evidence becomes available.
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Affiliation(s)
- Michael G Tyshenko
- a McLaughlin Centre for Population Health Risk Assessment , Institute of Population Health, University of Ottawa , Ottawa , Ontario , Canada
| | - Tamer Oraby
- b Department of Mathematics , University of Texas-Pan American , Edinburg , Texas , USA
| | - Shalu Darshan
- a McLaughlin Centre for Population Health Risk Assessment , Institute of Population Health, University of Ottawa , Ottawa , Ontario , Canada
| | - Margit Westphal
- a McLaughlin Centre for Population Health Risk Assessment , Institute of Population Health, University of Ottawa , Ottawa , Ontario , Canada
| | - Maxine C Croteau
- a McLaughlin Centre for Population Health Risk Assessment , Institute of Population Health, University of Ottawa , Ottawa , Ontario , Canada
| | - Willy Aspinall
- c Aspinall and Associates , Tisbury , United Kingdom
- d School of Earth Sciences and Cabot Institute , University of Bristol , Bristol , United Kingdom
| | - Susie Elsaadany
- e Professional Guidelines and Public Health Practice Division, Centre for Infectious Disease Prevention and Control , Public Health Agency of Canada , Ottawa , Ontario , Canada
| | - Daniel Krewski
- a McLaughlin Centre for Population Health Risk Assessment , Institute of Population Health, University of Ottawa , Ottawa , Ontario , Canada
- f Department of Epidemiology and Community Medicine , University of Ottawa , Ottawa , Ontario , Canada
| | - Neil Cashman
- g Brain Research Centre , University of British Columbia , Vancouver , British Columbia , Canada
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Oraby T, Tyshenko MG, Westphal M, Darshan S, Croteau MC, Aspinall W, Elsaadany S, Cashman N, Krewski D. Using expert judgments to improve chronic wasting disease risk management in Canada. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:713-728. [PMID: 27556565 DOI: 10.1080/15287394.2016.1174005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
ABSTARCT Chronic wasting disease (CWD) is a neurodegenerative, protein misfolding disease affecting cervids in North America in epidemic proportions. While the existence of CWD has been known for more than 40 years, risk management efforts to date have not been able to curtail the spread of this condition. An expert elicitation exercise was carried out in May 2011 to obtain the views of international experts on both the etiology of CWD and possible CWD risk management strategies. This study presents the results of the following three components of the elicitation exercise: (1) expert views of the most likely scenarios for the evolution of the CWD among cervid populations in Canada, (2) ranking analyses of the importance of direct and indirect transmission routes, and (3) rating analyses of CWD control measures in farmed and wild cervids. The implications of these findings for the development of CWD risk management strategies are described in a Canadian context.
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Affiliation(s)
- Tamer Oraby
- a Department of Mathematics , University of Texas Rio Grande Valley , Edinburg , Texas , USA
| | - Michael G Tyshenko
- b McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health , University of Ottawa , Ottawa , Ontario , Canada
| | - Margit Westphal
- b McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health , University of Ottawa , Ottawa , Ontario , Canada
| | - Shalu Darshan
- b McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health , University of Ottawa , Ottawa , Ontario , Canada
| | - Maxine C Croteau
- b McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health , University of Ottawa , Ottawa , Ontario , Canada
| | - Willy Aspinall
- c Aspinall and Associates , Tisbury , United Kingdom
- h Risk Sciences International , Ottawa , Ontario , Canada
| | - Susie Elsaadany
- d School of Earth Sciences and Cabot Institute , University of Bristol , Bristol , United Kingdom
| | - Neil Cashman
- e Blood Safety Surveillance and Health Care Acquired Infections Division , Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada , Ottawa , Ontario , Canada
| | - Daniel Krewski
- b McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health , University of Ottawa , Ottawa , Ontario , Canada
- f Brain Research Centre , University of British Columbia , Vancouver , British Columbia , Canada
- g Department of Epidemiology and Community Medicine, Faculty of Medicine , University of Ottawa , Ottawa , Ontario , Canada
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Kuznetsova A, McKenzie D, Banser P, Siddique T, Aiken JM. Potential role of soil properties in the spread of CWD in western Canada. Prion 2015; 8:92-9. [PMID: 24618673 DOI: 10.4161/pri.28467] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Chronic wasting disease (CWD) is a horizontally transmissible prion disease of free ranging deer, elk and moose. Recent experimental transmission studies indicate caribou are also susceptible to the disease. CWD is present in southeast Alberta and southern Saskatchewan. This CWD-endemic region is expanding, threatening Manitoba and areas of northern Alberta and Saskatchewan, home to caribou. Soil can serve as a stable reservoir for infectious prion proteins; prions bound to soil particles remain infectious in the soils for many years. Soils of western Canada are very diverse and the ability of CWD prions to bind different soils and the impact of this interaction on infectivity is not known. In general, clay-rich soils may bind prions avidly and enhance their infectivity comparable to pure clay mineral montmorillonite. Organic components of soils are also diverse and not well characterized, yet can impact prion-soil interaction. Other important contributing factors include soil pH, composition of soil solution and amount of metals (metal oxides). In this review, properties of soils of the CWD-endemic region in western Canada with its surrounding terrestrial environment are described and used to predict bioavailability and, thus, potential spread of CWD. The major soils in the CWD-endemic region of Alberta and Saskatchewan are Chernozems, present in 60% of the total area; they are generally similar in texture, clay mineralogy and soil organic matter content, and can be characterized as clay loamy, montmorillonite (smectite) soils with 6-10% organic carbon. The greatest risk of CWD spread in western Canada relates to clay loamy, montmorillonite soils with humus horizon. Such soils are predominant in the southern region of Alberta, Saskatchewan and Manitoba, but are less common in northern regions of the provinces where quartz-illite sandy soils with low amount of humus prevail.
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Jacobson KH, Kuech TR, Pedersen JA. Attachment of pathogenic prion protein to model oxide surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6925-34. [PMID: 23611152 PMCID: PMC4091914 DOI: 10.1021/es3045899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Prions are the infectious agents in the class of fatal neurodegenerative diseases known as transmissible spongiform encephalopathies, which affect humans, deer, sheep, and cattle. Prion diseases of deer and sheep can be transmitted via environmental routes, and soil is has been implicated in the transmission of these diseases. Interaction with soil particles is expected to govern the transport, bioavailability and persistence of prions in soil environments. A mechanistic understanding of prion interaction with soil components is critical for understanding the behavior of these proteins in the environment. Here, we report results of a study to investigate the interactions of prions with model oxide surfaces (Al2O3, SiO2) using quartz crystal microbalance with dissipation monitoring and optical waveguide light mode spectroscopy. The efficiency of prion attachment to Al2O3 and SiO2 depended strongly on pH and ionic strength in a manner consistent with electrostatic forces dominating interaction with these oxides. The presence of the N-terminal portion of the protein appeared to promote attachment to Al2O3 under globally electrostatically repulsive conditions. We evaluated the utility of recombinant prion protein as a surrogate for prions in attachment experiments and found that its behavior differed markedly from that of the infectious agent. Our findings suggest that prions would tend to associate with positively charged mineral surfaces in soils (e.g., iron and aluminum oxides).
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Affiliation(s)
- Kurt H. Jacobson
- Department of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706
| | - Thomas R. Kuech
- Environmental Chemistry and Technology Program, University of Wisconsin, Madison, WI 53706
| | - Joel A. Pedersen
- Department of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706
- Environmental Chemistry and Technology Program, University of Wisconsin, Madison, WI 53706
- Department of Soil Science, University of Wisconsin, Madison, WI 53706
- Corresponding author address: Department of Soil Science, University of Wisconsin, 1525 Observatory Drive, Madison, WI 53706 1299; phone: (608) 263-4971; fax: (608) 265-2595;
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Nichols TA, Spraker TR, Rigg TD, Meyerett-Reid C, Hoover C, Michel B, Bian J, Hoover E, Gidlewski T, Balachandran A, O'Rourke K, Telling GC, Bowen R, Zabel MD, VerCauteren KC. Intranasal inoculation of white-tailed deer (Odocoileus virginianus) with lyophilized chronic wasting disease prion particulate complexed to montmorillonite clay. PLoS One 2013; 8:e62455. [PMID: 23671598 PMCID: PMC3650006 DOI: 10.1371/journal.pone.0062455] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/21/2013] [Indexed: 11/19/2022] Open
Abstract
Chronic wasting disease (CWD), the only known prion disease endemic in wildlife, is a persistent problem in both wild and captive North American cervid populations. This disease continues to spread and cases are found in new areas each year. Indirect transmission can occur via the environment and is thought to occur by the oral and/or intranasal route. Oral transmission has been experimentally demonstrated and although intranasal transmission has been postulated, it has not been tested in a natural host until recently. Prions have been shown to adsorb strongly to clay particles and upon oral inoculation the prion/clay combination exhibits increased infectivity in rodent models. Deer and elk undoubtedly and chronically inhale dust particles routinely while living in the landscape while foraging and rutting. We therefore hypothesized that dust represents a viable vehicle for intranasal CWD prion exposure. To test this hypothesis, CWD-positive brain homogenate was mixed with montmorillonite clay (Mte), lyophilized, pulverized and inoculated intranasally into white-tailed deer once a week for 6 weeks. Deer were euthanized at 95, 105, 120 and 175 days post final inoculation and tissues examined for CWD-associated prion proteins by immunohistochemistry. Our results demonstrate that CWD can be efficiently transmitted utilizing Mte particles as a prion carrier and intranasal exposure.
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Affiliation(s)
- Tracy A Nichols
- National Wildlife Research Center, US Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, Colorado, USA.
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Saunders SE, Bartelt-Hunt SL, Bartz JC. Resistance of soil-bound prions to rumen digestion. PLoS One 2012; 7:e44051. [PMID: 22937149 PMCID: PMC3427226 DOI: 10.1371/journal.pone.0044051] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 07/27/2012] [Indexed: 11/18/2022] Open
Abstract
Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrPc from complete digestion, while both unbound and soil-bound infectious PrPSc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment.
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Affiliation(s)
- Samuel E. Saunders
- Department of Civil Engineering, University of Nebraska-Lincoln, Peter Kiewit Institute, Omaha, Nebraska, United States of America
| | - Shannon L. Bartelt-Hunt
- Department of Civil Engineering, University of Nebraska-Lincoln, Peter Kiewit Institute, Omaha, Nebraska, United States of America
- * E-mail:
| | - Jason C. Bartz
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
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Role of prion protein aggregation in neurotoxicity. Int J Mol Sci 2012; 13:8648-8669. [PMID: 22942726 PMCID: PMC3430257 DOI: 10.3390/ijms13078648] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/29/2012] [Accepted: 07/02/2012] [Indexed: 11/17/2022] Open
Abstract
In several neurodegenerative diseases, such as Parkinson, Alzheimer’s, Huntington, and prion diseases, the deposition of aggregated misfolded proteins is believed to be responsible for the neurotoxicity that characterizes these diseases. Prion protein (PrP), the protein responsible of prion diseases, has been deeply studied for the peculiar feature of its misfolded oligomers that are able to propagate within affected brains, inducing the conversion of the natively folded PrP into the pathological conformation. In this review, we summarize the available experimental evidence concerning the relationship between aggregation status of misfolded PrP and neuronal death in the course of prion diseases. In particular, we describe the main findings resulting from the use of different synthetic (mainly PrP106-126) and recombinant PrP-derived peptides, as far as mechanisms of aggregation and amyloid formation, and how these different spatial conformations can affect neuronal death. In particular, most data support the involvement of non-fibrillar oligomers rather than actual amyloid fibers as the determinant of neuronal death.
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Saunders SE, Bartz JC, Bartelt-Hunt SL. Soil-mediated prion transmission: is local soil-type a key determinant of prion disease incidence? CHEMOSPHERE 2012; 87:661-667. [PMID: 22265680 DOI: 10.1016/j.chemosphere.2011.12.076] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/23/2011] [Accepted: 12/28/2011] [Indexed: 05/31/2023]
Abstract
Prion diseases, including chronic wasting disease (CWD) and scrapie, can be transmitted via indirect environmental routes. Animals habitually ingest soil, and results from laboratory experiments demonstrate prions can bind to a wide range of soils and soil minerals, retain the ability to replicate, and remain infectious, indicating soil could serve as a reservoir for natural prion transmission and a potential prion exposure route for humans. Preliminary epidemiological modeling suggests soil texture may influence the incidence of prion disease. These results are supported by experimental work demonstrating variance in prion interactions with soil, including variance in prion soil adsorption and soil-bound prion replication with respect to soil type. Thus, local soil type may be a key determinant of prion incidence. Further experimental and epidemiological work is required to fully elucidate the dynamics of soil-mediated prion transmission, an effort that should lead to effective disease management and mitigation strategies.
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Affiliation(s)
- Samuel E Saunders
- Department of Civil Engineering, University of Nebraska-Lincoln, Peter Kiewit Institute, Omaha, NE 68182, USA
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