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Simmons SM, Payne VL, Hrdlicka JG, Taylor J, Larsen PA, Wolf TM, Schwabenlander MD, Yuan Q, Bartz JC. Rapid and sensitive determination of residual prion infectivity from prion-decontaminated surfaces. mSphere 2024:e0050424. [PMID: 39189773 DOI: 10.1128/msphere.00504-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Accepted: 07/21/2024] [Indexed: 08/28/2024] Open
Abstract
Prion diseases are untreatable fatal transmissible neurodegenerative diseases that affect a wide range of mammals, including humans, and are caused by PrPSc, the infectious self-templating conformation of the host-encoded protein, PrPC. Prion diseases can be transmitted via surfaces (e.g., forceps, EEG electrodes) in laboratory and clinical settings. Here, we use a combination of surface swabbing and real-time quaking-induced conversion (RT-QuIC) to test for residual surface-associated prions following prion disinfection. We found that treatment of several prion-contaminated laboratory and clinically relevant surfaces with either water or 70% EtOH resulted in robust detection of surface-associated prions. In contrast, treatment of surfaces with sodium hypochlorite resulted in a failure to detect surface-associated prions. RT-QuIC analysis of prion-contaminated stainless steel wires paralleled the findings of the surface swab studies. Importantly, animal bioassay and RT-QuIC analysis of the same swab extracts are in agreement. We report on conditions that may interfere with the assay that need to be taken into consideration before using this technique. Overall, this method can be used to survey laboratory and clinical surfaces for prion infectivity following prion decontamination protocols.IMPORTANCEPrion diseases can be accidentally transmitted in clinical and occupational settings. While effective means of prion decontamination exist, methods for determining the effectiveness are only beginning to be described. Here, we analyze surface swab extracts using real-time quaking-induced conversion (RT-QuIC) to test for residual prions following prion disinfection of relevant clinical and laboratory surfaces. We found that this method can rapidly determine the efficacy of surface prion decontamination. Importantly, examination of surface extracts with RT-QuIC and animal bioassay produced similar findings, suggesting that this method can accurately assess the reduction in prion titer. We identified surface contaminants that interfere with the assay, which may be found in clinical and laboratory settings. Overall, this method can enhance clinical and laboratory prion safety measures.
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Affiliation(s)
- Sara M Simmons
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska, USA
| | | | - Jay G Hrdlicka
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska, USA
| | - Jack Taylor
- Biostatistical Core Facility, Creighton University, Omaha, Nebraska, USA
| | - Peter A Larsen
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
| | - Tiffany M Wolf
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
| | - Marc D Schwabenlander
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
| | - Qi Yuan
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska, USA
| | - Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska, USA
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
- Prion Research Center, Colorado State University, Fort Collins, Colorado, USA
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2
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Gerba CP, Boone S, Nims RW, Maillard JY, Sattar SA, Rubino JR, McKinney J, Ijaz MK. Mechanisms of action of microbicides commonly used in infection prevention and control. Microbiol Mol Biol Rev 2024:e0020522. [PMID: 38958456 DOI: 10.1128/mmbr.00205-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
Abstract
SUMMARYUnderstanding how commonly used chemical microbicides affect pathogenic microorganisms is important for formulation of microbicides. This review focuses on the mechanism(s) of action of chemical microbicides commonly used in infection prevention and control. Contrary to the typical site-specific mode of action of antibiotics, microbicides often act via multiple targets, causing rapid and irreversible damage to microbes. In the case of viruses, the envelope or protein capsid is usually the primary structural target, resulting in loss of envelope integrity or denaturation of proteins in the capsid, causing loss of the receptor-binding domain for host cell receptors, and/or breakdown of other viral proteins or nucleic acids. However, for certain virucidal microbicides, the nucleic acid may be a significant site of action. The region of primary damage to the protein or nucleic acid is site-specific and may vary with the virus type. Due to their greater complexity and metabolism, bacteria and fungi offer more targets. The rapid and irreversible damage to microbes may result from solubilization of lipid components and denaturation of enzymes involved in the transport of nutrients. Formulation of microbicidal actives that attack multiple sites on microbes, or control of the pH, addition of preservatives or potentiators, and so on, can increase the spectrum of action against pathogens and reduce both the concentrations and times needed to achieve microbicidal activity against the target pathogens.
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Affiliation(s)
- Charles P Gerba
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Stephanie Boone
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | | | - Jean-Yves Maillard
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Syed A Sattar
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Julie McKinney
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, New Jersey, USA
| | - M Khalid Ijaz
- Global Research and Development for Lysol and Dettol, Reckitt Benckiser LLC, Montvale, New Jersey, USA
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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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Paspaltsis I, Kanata E, Sotiriadis S, Correia SS, Schmitz M, Zerr I, Dafou D, Xanthopoulos K, Sklaviadis T. A Comparison of RML Prion Inactivation Efficiency by Heterogeneous and Homogeneous Photocatalysis. Pathogens 2024; 13:420. [PMID: 38787272 PMCID: PMC11124347 DOI: 10.3390/pathogens13050420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/10/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
Prions are proteinaceous pathogens responsible for a variety of devastating diseases in mammals, including scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt-Jakob disease (CJD) in humans. They are characterized by their exceptional persistence to common inactivation procedures. This applies to all possible sources of prion contamination as prions may be present in the tissues and biological fluids of infected individuals. Hence, efficient prion inactivation procedures are still being sought to minimize the risk of intra- or inter-species transmission. In the past, photocatalytic treatment has been proven to be capable of efficiently oxidizing and inactivating prions. In the present study, the efficacy of homogeneous photo-Fenton-based photocatalysis as well as heterogeneous photocatalysis with TiO2 in reducing RML mouse scrapie infectivity was evaluated. Prion inactivation was assessed by means of a bioassay, and the results were confirmed by in vitro experiments. While the prion infectivity of the RML mouse scrapie was reduced after treatment with the photo-Fenton reagent, the heterogeneous photocatalytic treatment of the same prion strain completely eliminated prion infectivity.
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Affiliation(s)
- Ioannis Paspaltsis
- Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.P.); (E.K.); (S.S.)
| | - Eirini Kanata
- Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.P.); (E.K.); (S.S.)
| | - Sotirios Sotiriadis
- Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.P.); (E.K.); (S.S.)
| | - Susana Silva Correia
- Department of Neurology, University Medicine Goettingen, German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Matthias Schmitz
- Department of Neurology, University Medicine Goettingen, German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Inga Zerr
- Department of Neurology, University Medicine Goettingen, German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Dimitra Dafou
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Konstantinos Xanthopoulos
- Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.P.); (E.K.); (S.S.)
- Centre for Research and Technology Hellas, Institute of Applied Biosciences, 57001 Thermi, Greece
| | - Theodoros Sklaviadis
- Laboratory of Pharmacology, Department of Pharmacy, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.P.); (E.K.); (S.S.)
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Baune C, Groveman BR, Hughson AG, Thomas T, Twardoski B, Priola S, Chesebro B, Race B. Efficacy of Wex-cide 128 disinfectant against multiple prion strains. PLoS One 2023; 18:e0290325. [PMID: 37616303 PMCID: PMC10449212 DOI: 10.1371/journal.pone.0290325] [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: 06/29/2023] [Accepted: 08/03/2023] [Indexed: 08/26/2023] Open
Abstract
Prion diseases are transmissible, fatal neurologic diseases that include Creutzfeldt-Jakob Disease (CJD) in humans, chronic wasting disease (CWD) in cervids, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. Prions are extremely difficult to inactivate and established methods to reduce prion infectivity are often dangerous, caustic, expensive, or impractical. Identifying viable and safe methods for treating prion contaminated materials is important for hospitals, research facilities, biologists, hunters, and meat-processors. For three decades, some prion researchers have used a phenolic product called Environ LpH (eLpH) to inactivate prions. ELpH has been discontinued, but a similar product, Wex-cide 128, containing the similar phenolic chemicals as eLpH is now available. In the current study, we directly compared the anti-prion efficacy of eLpH and Wex-cide 128 against prions from four different species (hamster 263K, cervid CWD, mouse 22L and human CJD). Decontamination was performed on either prion infected brain homogenates or prion contaminated steel wires and mouse bioassay was used to quantify the remaining prion infectivity. Our data show that both eLpH and Wex-cide 128 removed 4.0-5.5 logs of prion infectivity from 22L, CWD and 263K prion homogenates, but only about 1.25-1.50 logs of prion infectivity from human sporadic CJD. Wex-cide 128 is a viable substitute for inactivation of most prions from most species, but the resistance of CJD to phenolic inactivation is a concern and emphasizes the fact that inactivation methods should be confirmed for each target prion strain.
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Affiliation(s)
- Chase Baune
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Bradley R. Groveman
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Andrew G. Hughson
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Tina Thomas
- Rocky Mountain Veterinary Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Barry Twardoski
- Office of Operations Management, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Suzette Priola
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Bruce Chesebro
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Brent Race
- The Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
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Chiavacci SJ. The economic costs of chronic wasting disease in the United States. PLoS One 2022; 17:e0278366. [PMID: 36480524 PMCID: PMC9731425 DOI: 10.1371/journal.pone.0278366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 11/09/2022] [Indexed: 12/13/2022] Open
Abstract
Cervids are economically important to a wide range of stakeholders and rights holders in the United States. The continued expansion of chronic wasting disease (CWD), a fatal neurodegenerative disease affecting wild and farmed cervids, poses a direct and indirect threat to state and federal government agency operations and cervid related economic activity. However, the scale of this disease's direct economic costs is largely unknown. I synthesized existing publicly available data and stakeholder-provided data to estimate CWD's costs within the continental United States. Federal government agencies collectively spent over $284.1 million on CWD-related efforts between 2000 and 2021, with $203.6 million of this total being spent by the U.S. Department of Agriculture's Animal and Plant Health Inspection Service. In fiscal year 2020, state natural resources agencies and state agriculture/animal health agencies spent over $25.5 million and $2.9 million, respectively, on CWD-related work. Natural resources agencies in states with known CWD cases spent over 8 times as much on CWD as agencies from states with no known cases. The farmed cervid industry spent at least $307,950 on CWD sampling in 2020, though a lack of available data prevented a complete assessment of costs to this industry. Based on limited data, CWD's economic effects on the hunting industry (i.e., outfitters and guides, companies leasing land to cervid hunters), may be negligible at this time. Overall, however, the realized economic costs of CWD appear considerable, and it is likely that the number of stakeholders financially affected by this disease and regulations meant to stem its spread will continue to grow. By understanding the current economic impacts of CWD, we are better positioned to assess the costs and benefits of investments in management and research and to understand the magnitude of this disease's broader societal impacts.
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Affiliation(s)
- Scott J. Chiavacci
- U.S. Geological Survey, Science and Decisions Center, Reston, VA, United States of America
- * E-mail:
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Standke HG, Kraus A. Seed amplification and RT-QuIC assays to investigate protein seed structures and strains. Cell Tissue Res 2022; 392:323-335. [PMID: 35258712 DOI: 10.1007/s00441-022-03595-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/27/2022] [Indexed: 12/13/2022]
Abstract
The accumulation of misfolded proteins as amyloid fibrils in the brain is characteristic of most neurodegenerative disorders. These misfolded proteins are capable of self-amplifying through protein seeding mechanisms, leading to accumulation in the host. First shown for PrP prions and prion diseases, it is now recognized that self-propagating misfolded proteins occur broadly in neurodegenerative diseases and include amyloid-β (Aβ) and tau in Alzheimer's disease (AD), tau in chronic traumatic encephalopathy (CTE), Pick's disease (PiD), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), and α-synuclein (α-syn) in Parkinson's disease (PD) and Lewy body dementias (LBD). Techniques able to directly measure these bioactive protein seeds include the real-time quaking-induced conversion (RT-QuIC) assays. Initially developed for the detection of PrP prions and subsequently for the detection of other misfolded protein seeds, these assays take advantage of the mechanism of protein-based self-propagation to result in exponential amplification of the initial protein seeds from biospecimens. Disease-specific "protein seeds" recruit and template the misfolding of native recombinant protein substrates to elongate amyloid fibrils. The amplification power of these assays allows for detection of minute amounts of disease-specific protein seeds to better support early and accurate diagnosis. In addition to the diagnostic capabilities, assay readouts have been shown to reveal biochemical, structural, and kinetic information of protein seed self-propagation. This review examines the various protein seed amplification assays currently available for distinct neurodegenerative diseases, with a focus on RT-QuIC assays, along with the insights their readouts provide into protein seed structures and strain differences.
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Affiliation(s)
- Heidi G Standke
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Allison Kraus
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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Abstract
Chronic wasting disease (CWD) is a transmissible prion disease first observed in the 1960s in North America. This invariably fatal disease affects multiple cervid species in the wild and in captivity. In addition to the several known transmission pathways involving cervid host species, prions have been detected in the feces of crows and coyotes after consumption of experimentally spiked tissues. This raises questions about the role of cervid consumers in the perpetuation of CWD. Mountain lions have been shown to preferentially select CWD-infected prey and are also apparently resistant to infection. In this study, two captive mountain lions were fed ground mule deer muscle tissue spiked with brain-derived CWD prions, and lion feces were collected for 1 week afterward. The input brain and resulting fecal materials were analyzed using the highly sensitive real-time quaking-induced conversion (RT-QuIC) assay to quantify prion seeding activity. We recovered only 2.8 to 3.9% of input CWD prions after passage through the mountain lions’ gastrointestinal tracts. Interestingly, CWD prions were shed only in the first defecation following consumption. Our data support the possibility that mountain lions feeding upon infected carcasses could excrete CWD prions in their feces over a short period of time but also suggest that most of the ingested prions are eliminated or sequestered by this large predator. IMPORTANCE CWD prions appear to spread naturally among susceptible cervid species in captivity and in the wild. A better understanding of all the ways these prions move, persist, and subsequently infect target species through the environment is critical to developing comprehensive disease control strategies. In our study, we show limited, transient pass-through of CWD prions in an apex predator, the mountain lion, using the highly sensitive RT-QuIC assay on feces collected after lions were fed prion-spiked muscle tissue. Prions were detected in feces only in the first defecation after exposure. Moreover, the amount of CWD prions recovered in feces was reduced by >96% after passing through the lion digestive system. This indicates that mountain lions may have some potential to distribute CWD prions within their home ranges but that they also effectively eliminate most of the CWD prions they consume.
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Takada N, Niwa Y, Teshigawara T, Isogai K, Okura H, Matsuyama A. The integrity of chemically treated plasmid DNA as a chemical-based choice for prion clearance. Regen Ther 2021; 15:112-120. [PMID: 33426209 PMCID: PMC7770345 DOI: 10.1016/j.reth.2020.05.005] [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] [Received: 03/04/2020] [Revised: 04/20/2020] [Accepted: 05/03/2020] [Indexed: 11/16/2022] Open
Abstract
In regenerative medical products for clinical applications, a major concern is the risk of ruminant-derived materials developing transmissible spongiform encephalopathy (TSE) in the manufacturing process. Because of the risk of TSE causing prion disease, the raw materials derived from ruminants should be compliant with the “Standard for Biological Raw Materials” to ensure the quality and safety of pharmaceutical products. We therefore tested whether plasmid DNA could withstand four chemical reagents (Gdn-HCl, Gdn-SCN, TCA, or SDS), having referred to the report by Tateishi et al. [1], which describes how Creutzfeldt–Jakob disease pathogens can be inactivated by chemical reagents capable of producing a 7-log reduction in prion inactivation. We observed that plasmid DNA was mixed with chemical reagents and that the functionality of plasmid DNA was equivalent for both chemical and non-chemical treatment. The potency of plasmid DNA was monitored by the existence of DNA fragments and the function by which GFP proteins were produced by HEK293-cell transfected plasmid DNA. The existence of DNA fragments was detected in plasmid DNA treated by chemical reagents, except when undergoing TCA treatment. Additionally, when HEK293 cells were transfected with the plasmid DNA after chemical treatment, GFP protein was produced. These results indicate that plasmid DNA can withstand the chemical treatments for blocking prion transmission. Inactivation methods need to be carefully chosen based on the raw materials. Plasmid DNA withstood chemical treatment, undergoing Gdn-HCl, Gdn-SCN, and SDS for prion inactivation. The integrity of chemically treated plasmid DNA is not compromised as a result of the treatment.
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Affiliation(s)
- Nozomi Takada
- Department of Regenerative Medicine and Stem Cell Biology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Yasuharu Niwa
- Department of Regenerative Medicine Support Promotion Facility, Center for Research Promotion and Support, Toyoake, Aichi, Japan
| | - Tomoaki Teshigawara
- Department of Regenerative Medicine Support Promotion Facility, Center for Research Promotion and Support, Toyoake, Aichi, Japan
| | - Kazue Isogai
- Department of Regenerative Medicine and Stem Cell Biology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan
| | - Hanayuki Okura
- Department of Regenerative Medicine Support Promotion Facility, Center for Research Promotion and Support, Toyoake, Aichi, Japan
| | - Akifumi Matsuyama
- Department of Regenerative Medicine and Stem Cell Biology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan.,Department of Regenerative Medicine Support Promotion Facility, Center for Research Promotion and Support, Toyoake, Aichi, Japan
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Defining the Protein Seeds of Neurodegeneration using Real-Time Quaking-Induced Conversion Assays. Biomolecules 2020; 10:biom10091233. [PMID: 32854212 PMCID: PMC7564261 DOI: 10.3390/biom10091233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 02/07/2023] Open
Abstract
Neurodegenerative diseases are characterized by the accumulation of disease-related misfolded proteins. It is now widely understood that the characteristic self-amplifying (i.e., seeding) capacity once only attributed to the prions of transmissible spongiform encephalopathy diseases is a feature of other misfolded proteins of neurodegenerative diseases, including tau, Aβ, and αSynuclein (αSyn). Ultrasensitive diagnostic assays, known as real-time quaking-induced conversion (RT-QuIC) assays, exploit these seeding capabilities in order to exponentially amplify protein seeds from various biospecimens. To date, RT-QuIC assays have been developed for the detection of protein seeds related to known prion diseases of mammals, the αSyn aggregates of Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy, and the tau aggregates of Alzheimer’s disease, chronic traumatic encephalopathy, and other tauopathies including progressive supranuclear palsy. Application of these assays to premortem human biospecimens shows promise for diagnosis of neurodegenerative disease and is an area of active investigation. RT-QuIC assays are also powerful experimental tools that can be used to dissect seeding networks within and between tissues and to evaluate how protein seed distribution and quantity correlate to disease-related outcomes in a host. As well, RT-QuIC application may help characterize molecular pathways influencing protein seed accumulation, transmission, and clearance. In this review we discuss the application of RT-QuIC assays as diagnostic, experimental, and structural tools for detection and discrimination of PrP prions, tau, and αSyn protein seeds.
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Inactivation of Scrapie Prions by the Electrically Charged Disinfectant CAC-717. Pathogens 2020; 9:pathogens9070536. [PMID: 32635278 PMCID: PMC7400677 DOI: 10.3390/pathogens9070536] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/27/2020] [Accepted: 07/01/2020] [Indexed: 12/19/2022] Open
Abstract
Previous studies have revealed that the electrically charged disinfectant CAC-717 has strong virucidal and bactericidal effects but is safe for humans and animals. In this study, CAC-717 was further evaluated for its potential effects as a disinfectant against scrapie prions. Western blotting showed that CAC-717 reduced the amount of the abnormal isoform of prion protein (PrPSc) in prion-infected cell (ScN2a) lysates. Furthermore, the reduction of prion transmissibility was confirmed by a mouse bioassay, in which mice injected with scrapie prions pre-treated with CAC-717 survived longer than those injected with untreated scrapie prions. Lastly, to evaluate the seeding activity of ScN2a cell lysates treated with CAC-717, quantitative protein misfolding cyclic amplification (PMCA) was performed directly on ScN2a cell lysates treated with CAC-717, which showed that the median dose of PMCA (PMCA50) dropped from log9.95 to log5.20 after CAC-717 treatment, indicating more than a 4 log reduction. This suggests that the seeding activity of PrPSc is decreased by CAC-717. Collectively, these results suggest that CAC-717 has anti-prion activity, reducing both PrPSc conversion activity and prion transmissibility; thus, CAC-717 will be useful as a novel disinfectant in prion diseases.
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