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Iwamaru Y, Furusaki K, Sugiura K, Haritani M, Onodera T. Ceramic absorbed with calcium bicarbonate mesoscopic crystals partially inactivate scrapie prions. Microbiol Immunol 2023; 67:447-455. [PMID: 37517033 DOI: 10.1111/1348-0421.13092] [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: 02/28/2023] [Revised: 06/29/2023] [Accepted: 07/11/2023] [Indexed: 08/01/2023]
Abstract
Prion diseases are fatal neurodegenerative disorders affecting both humans and animals. The causative agent, prion, is extremely resistant to common disinfection procedures. Thus, effective prion inactivation strategies using relatively safe and less corrosive disinfectants are required. A solution containing CAC-717, mesoscopic crystals of calcium bicarbonate, exerts both antimicrobial and virucidal activities without apparent harmful effects. This study demonstrated that combined treatment with CAC-717 absorbed on ceramic (CAC-717 ceramic) and sodium dodecyl sulfate (SDS) substantially reduced the protein misfolding cyclic amplification (PMCA) seeding activity of Chandler strain scrapie mouse-brain homogenates (ScBH). Additionally, bioassays demonstrated that ScBH-inoculated mice treated with CAC-717 ceramic in combination with sodium dodecyl sulfate (SDS) did not develop disease. Furthermore, this combination effectively inactivated PMCA seeding activity on ScBH-coated stainless-steel wires below the detection limit. Overall, the findings suggest that combined treatment with CAC-717 ceramic and SDS represents a promising and less damaging approach for prion inactivation.
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Affiliation(s)
- Yoshifumi Iwamaru
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Koichi Furusaki
- Mineral Activation Technical Research Center, Omuta, Fukuoka, Japan
| | - Katsuaki Sugiura
- Environmental Science for Sustainable Development, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Makoto Haritani
- Environmental Science for Sustainable Development, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takashi Onodera
- Environmental Science for Sustainable Development, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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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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Langeveld JPM, Balkema-Buschmann A, Becher D, Thomzig A, Nonno R, Andréoletti O, Davidse A, Di Bari MA, Pirisinu L, Agrimi U, Groschup MH, Beekes M, Shih J. Stability of BSE infectivity towards heat treatment even after proteolytic removal of prion protein. Vet Res 2021; 52:59. [PMID: 33863379 PMCID: PMC8052740 DOI: 10.1186/s13567-021-00928-8] [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: 01/14/2021] [Accepted: 03/23/2021] [Indexed: 11/25/2022] Open
Abstract
The unconventional infectious agents of transmissible spongiform encephalopathies (TSEs) are prions. Their infectivity co-appears with PrPSc, aberrant depositions of the host's cellular prion protein (PrPC). Successive heat treatment in the presence of detergent and proteolysis by a keratinase from Bacillus licheniformis PWD-1 was shown before to destroy PrPSc from bovine TSE (BSE) and sheep scrapie diseased brain, however data regarding expected reduction of infectivity were still lacking. Therefore, transgenic Tgbov XV mice which are highly BSE susceptible were used to quantify infectivity before and after the bovine brain treatment procedure. Also four immunochemical analyses were applied to compare the levels of PrPSc. After heating at 115 °C with or without subsequent proteolysis, the original BSE infectivity of 106.2-6.4 ID50 g-1 was reduced to a remaining infectivity of 104.6-5.7 ID50 g-1 while strain characteristics were unaltered, even after precipitation with methanol. Surprisingly, PrPSc depletion was 5-800 times higher than the loss of infectivity. Similar treatment was applied on other prion strains, which were CWD1 in bank voles, 263 K scrapie in hamsters and sheep PG127 scrapie in tg338 ovinized mice. In these strains however, infectivity was already destroyed by heat only. These findings show the unusual heat resistance of BSE and support a role for an additional factor in prion formation as suggested elsewhere when producing prions from PrPC. Leftover material in the remaining PrPSc depleted BSE preparation offers a unique substrate for searching additional elements for prion infectivity and improving our concept about the nature of prions.
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Affiliation(s)
- Jan P M Langeveld
- Department of Infection Biology, Wageningen Bioveterinary Research (WBVR), 8221RA 39, Lelystad, The Netherlands.
| | - Anne Balkema-Buschmann
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Dieter Becher
- MICROMUN, Institut Für Mikrobiologische Forschung GmbH, 17489, Greifswald, Germany
| | - Achim Thomzig
- Prion and Prionoid Research Unit, Robert Koch-Institute, 13353, Berlin, Germany
| | - Romolo Nonno
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore Di Sanità, 00161, Rome, Italy
| | - Olivier Andréoletti
- UMR INRAE/ENVT 1225 IHAP, École Nationale Vétérinaire de Toulouse, 31300, Toulouse, France
| | - Aart Davidse
- Department of Infection Biology, Wageningen Bioveterinary Research (WBVR), 8221RA 39, Lelystad, The Netherlands
| | - Michele A Di Bari
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore Di Sanità, 00161, Rome, Italy
| | - Laura Pirisinu
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore Di Sanità, 00161, Rome, Italy
| | - Umberto Agrimi
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore Di Sanità, 00161, Rome, Italy
| | | | - Michael Beekes
- Prion and Prionoid Research Unit, Robert Koch-Institute, 13353, Berlin, Germany
| | - Jason Shih
- Department of Poultry Science, North Carolina State University, Raleigh, NC, 27695-7608, USA
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Sakudo A, Yamashiro R, Harata C. Effect of Non-Concentrated and Concentrated Vaporized Hydrogen Peroxide on Scrapie Prions. Pathogens 2020; 9:pathogens9110947. [PMID: 33202870 PMCID: PMC7696461 DOI: 10.3390/pathogens9110947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 11/16/2022] Open
Abstract
To date, there have been no studies on the sterilization of prions by non-concentrated and concentrated vaporized hydrogen peroxide (VHP) applied by the same instrument. Here, the effect of the two types of VHP applied using an ES-700 sterilizer on prions was investigated. Brain homogenate from scrapie (Chandler) prion-infected mice was spotted on a cover glass and subjected to ES-700 treatment in soft (non-concentrated VHP from 59% hydrogen peroxide) or standard (concentrated VHP from 80% hydrogen peroxide) mode. Proteinase K-resistant prion protein (PrPres), an indicator of the abnormal isoform of prion protein (PrPSc), was reduced by ES-700 treatment under several conditions: SFT1/4 (soft mode, quarter cycle), SFT1/2 (soft mode, half cycle), SFT1 (soft mode, full cycle), and STD1/2 (standard mode, half cycle). PrPres was detected after the first and second rounds of protein misfolding cyclic amplification (PMCA) of untreated samples, but was undetectable in SFT1/4, SFT1/2, SFT1, and STD1/2 treated samples. In a mouse bioassay, SFT1/2 and STD1/2 treatment of prions significantly prolonged survival time, suggesting that prion infectivity is reduced after ES-700 treatment. In summary, both non-concentrated and concentrated VHP inactivate prions and may be useful for the low-temperature sterilization of prion-contaminated medical devices.
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Affiliation(s)
- Akikazu Sakudo
- School of Veterinary Medicine, Okayama University of Science, Imabari, Ehime 794-8555, Japan
- Laboratory of Biometabolic Chemistry, School of Health Sciences, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan;
- Correspondence:
| | - Risa Yamashiro
- Laboratory of Biometabolic Chemistry, School of Health Sciences, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan;
| | - Chihiro Harata
- Canon Lifecare Solutions Inc., Minato-ku, Tokyo 108-0075, Japan;
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Matsuura Y, Ishikawa Y, Murayama Y, Yokoyama T, Somerville RA, Kitamoto T, Mohri S. Eliminating transmissibility of bovine spongiform encephalopathy by dry-heat treatment. J Gen Virol 2020; 101:136-142. [PMID: 31718739 DOI: 10.1099/jgv.0.001335] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bovine spongiform encephalopathy (BSE) prion is more resistant to heat inactivation compared to other prions, but the effect of heat inactivation has been reported to differ depending on the BSE-contaminated tissue state or heating type. We aimed to evaluate the secure level of inactivation of original BSE transmissibility by dry-heating. Cattle tissues affected with BSE were subjected to dry-heat treatment for 20 min at various temperatures ranging from 150 to 1000 °C. To assess the inactivation effect, we conducted protein misfolding cyclic amplification (PMCA) and follicular dendritic cell (FDC) assays in transgenic mice expressing bovine prion protein genes. Under dry-heating at 600 °C or higher, BSE cattle tissues lost their transmissibility in transgenic mice. In contrast, transmissibility was detected in the cattle tissues treated at temperatures of 400 °C or lower through the FDC assay combined with PMCA. In this study, we confirmed that transmissibility was eliminated in BSE-affected cattle tissues by dry-heating at 600 °C or higher.
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Affiliation(s)
- Yuichi Matsuura
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Yukiko Ishikawa
- Present address: International Institute for Integrative Sleep Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Yuichi Murayama
- Present address: Wildlife Research Center, Kyoto University, 2-24 Tanaka-Sekiden-cho, Sakyo, Kyoto, 606-8203, Japan.,National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Takashi Yokoyama
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Robert A Somerville
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9PS, UK
| | - Tetsuyuki Kitamoto
- Department of Neurological Science, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Shirou Mohri
- National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan.,Department of Neurological Science, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
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6
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Chapman GE, Lockey R, Beck KE, Vickery C, Arnold M, Thorne L, Thorne JK, Walker SR, Keulen L, Casalone C, Griffiths PC, Simmons MM, Terry LA, Spiropoulos J. Inactivation of H‐type and L‐type bovine spongiform encephalopathy following recommended autoclave decontamination procedures. Transbound Emerg Dis 2020. [DOI: 10.1111/tbed.13513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
| | | | - Katy E. Beck
- Animal and Plant Health Agency (APHA) Weybridge UK
| | | | - Mark Arnold
- Animal and Plant Health Agency (APHA) Weybridge UK
| | - Leigh Thorne
- Animal and Plant Health Agency (APHA) Weybridge UK
| | | | | | - Lucien Keulen
- Wageningen Bioveterinary Research Wageningen UR Lelystad The Netherlands
| | - Cristina Casalone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta Sede Centrale di Torino Turin Italy
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Abstract
Prion diseases are caused by the conversion of physiological PrPC into the pathogenic misfolded protein PrPSc, conferring new properties to PrPSc that vary upon prion strains. In this work, we analyze the thermostability of three prion strains (BSE, RML and 22L) that were heated at 98 °C for 2 hours. PrPSc resistance to proteinase K (PrPres), residual infectivity by mouse bioassay and in vitro templating activity by protein misfolding cyclic amplification (PMCA) were studied. Heated strains showed a huge loss of PrPres and a radically different infectivity loss: RML was the most thermolabile strain (6 to 7 log10 infectivity loss), followed by 22L (5 log10) while BSE was the most thermostable strain with low or null infectivity reduction showing a clear dissociation between PrPres and infectivity. These results indicate that thermostability is a strain-specific feature, measurable by PMCA and mouse bioassay, and a great tool to distinguish prion strains.
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8
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Spiropoulos J, Lockey R, Beck KE, Vickery C, Holder TM, Thorne L, Arnold M, Andreoletti O, Simmons MM, Terry LA. Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures. Transbound Emerg Dis 2019; 66:1993-2001. [PMID: 31111687 DOI: 10.1111/tbed.13247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/21/2019] [Accepted: 05/16/2019] [Indexed: 11/28/2022]
Abstract
Prions are highly resistant to the decontamination procedures normally used to inactivate conventional pathogens. This is a challenging problem not only in the medical and veterinary fields for minimizing the risk of transmission from potentially infective sources but also for ensuring the safe disposal or subsequent use of animal by-products. Specific pressure autoclaving protocols were developed for this purpose, but different strains of prions have been reported to have differing resistance patterns to established prion decontamination procedures, and as additional TSE strains are identified it is necessary to determine the effectiveness of such procedures. In this study we assessed the efficacy of sterilization using the EU recommended autoclave procedure for prions (133°C, 3 Bar for 20 min) on the atypical or Nor98 (AS/Nor98) scrapie strain of sheep and goats. Using a highly sensitive murine mouse model (tg338) that overexpresses ovine PrPC , we determined that this method of decontamination reduced the infectivity titre by 1010 . Infectivity was nonetheless still detected after applying the recommended autoclaving protocol. This shows that AS/Nor98 can survive the designated legislative decontamination conditions, albeit with a significant decrease in titre. The infectivity of a classical scrapie isolate subjected to the same decontamination conditions was reduced by 106 suggesting that the AS/Nor98 isolate is less sensitive to decontamination than the classical scrapie source.
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Affiliation(s)
| | - Richard Lockey
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Katy E Beck
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Chris Vickery
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Thomas M Holder
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Leigh Thorne
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Mark Arnold
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
| | - Olivier Andreoletti
- UMR INRA ENVT 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France
| | | | - Linda A Terry
- Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
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9
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Bett C, Grgac K, Long D, Karfunkle M, Keire DA, Asher DM, Gregori L. A Heparin Purification Process Removes Spiked Transmissible Spongiform Encephalopathy Agent. AAPS JOURNAL 2017; 19:765-771. [DOI: 10.1208/s12248-017-0047-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/11/2017] [Indexed: 02/08/2023]
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11
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Matsuura Y, Ishikawa Y, Bo X, Murayama Y, Yokoyama T, Somerville RA, Kitamoto T, Mohri S. Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy. Biochem Biophys Res Commun 2013; 432:86-91. [DOI: 10.1016/j.bbrc.2013.01.081] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 01/12/2013] [Indexed: 01/30/2023]
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12
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Fernie K, Hamilton S, Somerville RA. Limited efficacy of steam sterilization to inactivate vCJD infectivity. J Hosp Infect 2011; 80:46-51. [PMID: 22099953 DOI: 10.1016/j.jhin.2011.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 09/16/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND The transmission of bovine spongiform encephalopathy (BSE) to humans as variant Creutzfeldt-Jakob Disease (vCJD) raised concerns about potential secondary transmissions due to the resistance of the agents causing transmissible spongiform encephalopathies (TSEs), sometimes known as prions, to commonly used methods of sterilization, notably steam sterilization (or autoclaving). It has been suggested that surgical instruments and other medical devices might retain sufficient infected tissue debris after cleaning and steam sterilization to infect patients on whom they are subsequently used. AIM To determine whether concerns about the lack of efficacy of steam sterilization of vCJD were justified. METHODS The reduction in infectivity of brain macerates of vCJD brain after steam sterilization using the standard temperatures and time recommended for autoclaving in UK hospitals (134-137°C for 3 min) was measured. FINDINGS Reductions in titre of 10(2.3) to >10(3.6) ID(50) were found. In three of four samples, infectivity was recovered after steam sterilization. CONCLUSION As noted previously, TSE strains derived from BSE sources appear to be more resistant to steam sterilization and other forms of heat inactivation than other TSE sources.
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Affiliation(s)
- K Fernie
- Neurobiology Division, The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, UK
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Somerville RA, Gentles N. Characterization of the effect of heat on agent strains of the transmissible spongiform encephalopathies. J Gen Virol 2011; 92:1738-1748. [PMID: 21471321 DOI: 10.1099/vir.0.030452-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The causal agents of the transmissible spongiform encephalopathy (TSE) diseases, sometimes called prion diseases, are characterized by high resistance to inactivation with heat. Results from thermal inactivation experiments on nine TSE strains, seven passaged in two PrP genotypes, showed differences in sensitivity to heat inactivation ranging over 17 °C. In addition, the rate of inactivation with increasing temperature varied between TSE models. In some cases passage in an alternative PrP genotype had little effect on the resulting inactivation properties, but for others the infectious agent was inactivated at lower temperatures. No strain with higher thermostability properties was selected. The effect of mixing two TSE strains, to see whether their properties were affected through interaction with each other, was also examined. The results showed that both strains behaved as expected from the behaviour of the unmixed controls, and that the strain responsible for inducing TSE disease could be identified. There was no evidence of a direct effect on intrinsic strain properties. Overall, the results illustrate the diversity in properties of TSE strains. They require intrinsic molecular properties of TSE agents to accommodate high resistance to inactivation and a mechanism, independent of the host, to directly encode these differences. These findings are more readily reconciled with models of TSE agents with two separate components, one of which is independent of the host and comprises a TSE-specific nucleic acid, than with models based solely on conformational changes to a host protein.
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Affiliation(s)
- Robert A Somerville
- Neuropathogenesis Division, The Roslin Institute and Royal (Dick) Veterinary School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS, Scotland, UK
| | - Nicola Gentles
- Neuropathogenesis Division, The Roslin Institute and Royal (Dick) Veterinary School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS, Scotland, UK
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14
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Somerville RA, Fernie K, Smith A, Andrews R, Schmidt E, Taylor DM. Inactivation of a TSE agent by a novel biorefinement system. Process Biochem 2009. [DOI: 10.1016/j.procbio.2009.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Zampieri M, Legname G, Altafini C. Investigating the conformational stability of prion strains through a kinetic replication model. PLoS Comput Biol 2009; 5:e1000420. [PMID: 19578427 PMCID: PMC2697384 DOI: 10.1371/journal.pcbi.1000420] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 05/20/2009] [Indexed: 11/30/2022] Open
Abstract
Prion proteins are known to misfold into a range of different aggregated forms, showing different phenotypic and pathological states. Understanding strain specificities is an important problem in the field of prion disease. Little is known about which PrPSc structural properties and molecular mechanisms determine prion replication, disease progression and strain phenotype. The aim of this work is to investigate, through a mathematical model, how the structural stability of different aggregated forms can influence the kinetics of prion replication. The model-based results suggest that prion strains with different conformational stability undergoing in vivo replication are characterizable in primis by means of different rates of breakage. A further role seems to be played by the aggregation rate (i.e. the rate at which a prion fibril grows). The kinetic variability introduced in the model by these two parameters allows us to reproduce the different characteristic features of the various strains (e.g., fibrils' mean length) and is coherent with all experimental observations concerning strain-specific behavior. Prion diseases are caused by the accumulation of a cellular prion protein with an altered conformation, which acts as a catalyst for the further recruitment and the modification of the normal form of the protein. Protein polymerization appears to have a central role in the progression of the disease, an aspect shared with several other neurodegenerative diseases. The aim of this work is to investigate at the kinetic level the “prion strain phenomenon”, i.e., the ability of prion proteins to misfold into a range of different aggregated forms exhibiting different replication and propagation properties. The dynamics of prion replication is investigated with the help of a mathematical model. We relate a measurement accessible in vitro (prion structural stability) to a mathematical description of the fibrils' kinetics in vivo. The analysis of the model suggests that the replication kinetics of the different prion strains is characterizable by means of two parameters, representing the rates of breakage and aggregation. This result is coherent with various experimental findings concerning strain-specific behavior, such as, for example, the observation of the fibril mean length of the various strains.
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Affiliation(s)
- Mattia Zampieri
- Functional Analysis Sector, International School for Advanced Studies, Trieste, Italy
| | - Giuseppe Legname
- Neurobiology Sector, International School for Advanced Studies, Trieste, Italy
| | - Claudio Altafini
- Functional Analysis Sector, International School for Advanced Studies, Trieste, Italy
- * E-mail:
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16
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Pilon JL, Nash PB, Arver T, Hoglund D, Vercauteren KC. Feasibility of infectious prion digestion using mild conditions and commercial subtilisin. J Virol Methods 2009; 161:168-72. [PMID: 19467265 DOI: 10.1016/j.jviromet.2009.04.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 01/22/2009] [Accepted: 04/28/2009] [Indexed: 11/29/2022]
Abstract
Two serine protease enzymes, subtilisin 309 and subtilisin 309-v, were used to digest brain homogenates containing high levels of prion infectivity using mildly alkaline conditions to investigate prion decontamination methods. To establish that PrP(res) infectivity was eliminated, we utilized the Rocky Mountain Laboratory (RML) mouse-adapted scrapie model system for bioassay. Only one digestion condition (subtilisin 309 at 138mAU/ml, 55 degrees C and 14h digestion time pH 7.9) was considered to be highly relevant statistically (P<0.001) compared to control, with 52% of challenged mice surviving until the end of the study period. In contrast, treatment of PrP(res) by autoclaving at 134 degrees C or treatment with hypochlorite at a concentration of 20,000 ppm completely protected mice from prionosis. Further, in vitro assays suggest that potential proteolytic based PrP(res) decontamination methods must use high enzyme concentration, pH values >9.0, and elevated temperatures to be a safely efficacious, thereby limiting applicability on delicate surgical instruments and use in the environment.
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Affiliation(s)
- John L Pilon
- National Wildlife Research Center, 4101 Laporte Ave., Fort Collins, CO 80521, USA.
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17
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Dickinson J, Murdoch H, Dennis M, Hall G, Bott R, Crabb W, Penet C, Sutton J, Raven N. Decontamination of prion protein (BSE301V) using a genetically engineered protease. J Hosp Infect 2009; 72:65-70. [DOI: 10.1016/j.jhin.2008.12.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 12/15/2008] [Indexed: 01/09/2023]
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18
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Giles K, Glidden DV, Beckwith R, Seoanes R, Peretz D, DeArmond SJ, Prusiner SB. Resistance of bovine spongiform encephalopathy (BSE) prions to inactivation. PLoS Pathog 2008; 4:e1000206. [PMID: 19008948 PMCID: PMC2576443 DOI: 10.1371/journal.ppat.1000206] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Accepted: 10/15/2008] [Indexed: 11/18/2022] Open
Abstract
Distinct prion strains often exhibit different incubation periods and patterns of neuropathological lesions. Strain characteristics are generally retained upon intraspecies transmission, but may change on transmission to another species. We investigated the inactivation of two related prions strains: BSE prions from cattle and mouse-passaged BSE prions, termed 301V. Inactivation was manipulated by exposure to sodium dodecyl sulfate (SDS), variations in pH, and different temperatures. Infectivity was measured using transgenic mouse lines that are highly susceptible to either BSE or 301V prions. Bioassays demonstrated that BSE prions are up to 1,000-fold more resistant to inactivation than 301V prions while Western immunoblotting showed that short acidic SDS treatments reduced protease-resistant PrP(Sc) from BSE prions and 301V prions at similar rates. Our findings argue that despite being derived from BSE prions, mouse 301V prions are not necessarily a reliable model for cattle BSE prions. Extending these comparisons to human sporadic Creutzfeldt-Jakob disease and hamster Sc237 prions, we found that BSE prions were 10- and 10(6)-fold more resistant to inactivation, respectively. Our studies contend that any prion inactivation procedures must be validated by bioassay against the prion strain for which they are intended to be used.
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Affiliation(s)
- Kurt Giles
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - David V. Glidden
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America
| | - Robyn Beckwith
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
| | - Rose Seoanes
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
| | - David Peretz
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Stephen J. DeArmond
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Stanley B. Prusiner
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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Risks of transmitting ruminant spongiform encephalopathies (prion diseases) by semen and embryo transfer techniques. Theriogenology 2008; 70:725-45. [DOI: 10.1016/j.theriogenology.2008.05.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/12/2008] [Accepted: 05/14/2008] [Indexed: 11/21/2022]
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20
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Müller H, Stitz L, Riesner D. Prion decontamination during the oleochemical process of fat hydrogenation. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200700171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Henrik Müller
- Institut für Physikalische Biologie, Heinrich‐Heine‐Universität Düsseldorf, Düsseldorf, Germany
| | - Lothar Stitz
- Institut für Immunologie, Friedrich‐Loeffler‐Institut (FLI), Bundesforschungsinstitut für Tiergesundheit, Tübingen, Germany
| | - Detlev Riesner
- Institut für Physikalische Biologie, Heinrich‐Heine‐Universität Düsseldorf, Düsseldorf, Germany
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21
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Fichet G, Antloga K, Comoy E, Deslys J, McDonnell G. Prion inactivation using a new gaseous hydrogen peroxide sterilisation process. J Hosp Infect 2007; 67:278-86. [DOI: 10.1016/j.jhin.2007.08.020] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 08/23/2007] [Indexed: 11/16/2022]
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22
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Zinn RA, Jorquera AP. Feed Value of Supplemental Fats Used in Feedlot Cattle Diets. Vet Clin North Am Food Anim Pract 2007; 23:247-68, vi-vii. [PMID: 17606149 DOI: 10.1016/j.cvfa.2007.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The inclusion of supplemental fats in growing-finishing diets for feedlot cattle also improves diet "condition." Quality factors that may influence the feeding value of fat include the source of fat; moisture, impurities, and unsaponifiables; free fatty acid concentration; degree of saturation or titer; and rancidity (peroxide value). The net energy value of fat declines linearly with an increasing level of supplementation because of constraints on postruminal fatty acid digestion. The authors recommend that receiving diets not contain more than 2% supplemental fat. Little evidence suggests that the feeding value of fat is different for Holsteins than for conventional beef breeds. Fat supplementation is not consistent in its effect on intramuscular fat distribution (marbling), longissimus (rib eye) area, and fat thickness, but can be expected to increase dressing percentage and kidney, pelvic, and heart fat percentage.
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Affiliation(s)
- Richard Avery Zinn
- Department of Animal Science, University of California, Davis, CA 95616-8521, USA.
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23
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Fichet G, Comoy E, Dehen C, Challier L, Antloga K, Deslys JP, McDonnell G. Investigations of a prion infectivity assay to evaluate methods of decontamination. J Microbiol Methods 2007; 70:511-8. [PMID: 17640752 DOI: 10.1016/j.mimet.2007.06.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Accepted: 06/14/2007] [Indexed: 11/29/2022]
Abstract
Prions are unique infectious agents which have been shown to be transmitted iatrogenically through contaminated surfaces. Surface contamination is a concern on reusable medical devices and various industrial surfaces, but there is currently no standard, accepted model to evaluate surface prion decontamination. In this report, a set of both in vitro and in vivo methods were investigated based on the contamination of surface through artificial exposure to infected brain. An in vitro surface contamination protocol was developed with subsequent biochemical detection of the prion protein (PrPres). In parallel, the in vivo investigations included the contamination of different types of surface materials (stainless steel or plastic wires) with different prion strains (scrapie strain adapted to hamsters 263K or bovine spongiform encephalopathy strain adapted to mouse 6PB1). The in vivo models with various prion strains and brain homogenate dilutions reproducibly transmitted the disease and a relationship was established between the infectivity titre, the transmission rate and the incubation period. Moreover, the in vivo models were studied for their ability to demonstrate the efficacy of heat and chemical-based decontamination methods, with similar results. The in vivo scrapie method described is proposed as a standard to evaluate existing and developing prion decontamination technologies.
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Affiliation(s)
- Guillaume Fichet
- STERIS Laboratory, CEA/DSV/IMETI/SEPIA, Fontenay-aux-Roses, France.
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Gale P. The prion/lipid hypothesis - further evidence to support the molecular basis for transmissible spongiform encephalopathy risk assessment. J Appl Microbiol 2007; 103:2033-45. [DOI: 10.1111/j.1365-2672.2007.03411.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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25
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Gale P. The infectivity of transmissible spongiform encephalopathy agent at low doses: the importance of phospholipid. J Appl Microbiol 2007; 101:261-74. [PMID: 16882133 DOI: 10.1111/j.1365-2672.2006.03110.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The issue of whether the mechanism of infection is independent or co-operative for low doses of transmissible spongiform encephalopathy (TSE) agent is critical for risk assessment. The susceptibility (and hence ID(50)) of individuals with the same prion protein (PrP) genotype may vary considerably with a small proportion being very susceptible. Assuming independent action, the incubation period (IP) would continue to increase until the dose is below the ID(50) of the most susceptible individuals in the experiment, at which point it would become constant. This may explain the observed increase in IP with decreasing dose below the apparent ID(50) in experiments with untreated TSE agent. In contrast, IPs for autoclaved or NaOH-treated TSE agent increase greatly at doses <ID(50) suggesting strong co-operative action, or even a threshold. It is proposed here that the unit of infectivity for prion disease is a nucleation seed comprised of PrP and host phospholipid (PL). PL would play a structural role through mediating protein/lipid interactions with PrP. Heating or alkali treatment destroys the PL breaking up the nucleation seeds, which require long IPs to reform at low doses. Replenishing those inactivated PLs with host PL would explain how the phenotypic effect of long IP at low dose is lost on subpassage. It is proposed here that strain thermostability is controlled by the nature and strength of the PrP/PL interactions, which are independent of the host PrP genotype. Although repeated oral exposure to low doses of scrapie is less harmful than a single large exposure, this effect may reflect interference by competition rather than diminished risks due to a co-operative effect, and is of little importance for 'one-off' low-dose environmental exposures.
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Affiliation(s)
- P Gale
- Tilehurst, Reading, Berkshire, UK.
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26
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Stobart MJ, Parchaliuk D, Simon SLR, LeMaistre J, Lazar J, Rubenstein R, Knox JD. Differential expression of interferon responsive genes in rodent models of transmissible spongiform encephalopathy disease. Mol Neurodegener 2007; 2:5. [PMID: 17367538 PMCID: PMC1847514 DOI: 10.1186/1750-1326-2-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Accepted: 03/16/2007] [Indexed: 11/26/2022] Open
Abstract
Background The pathological hallmarks of transmissible spongiform encephalopathy (TSE) diseases are the deposition of a misfolded form of a host-encoded protein (PrPres), marked astrocytosis, microglial activation and spongiosis. The development of powerful gene based technologies has permitted increased levels of pro-inflammatory cytokines to be demonstrated. However, due to the use of assays of differing sensitivities and typically the analysis of a single model system it remained unclear whether this was a general feature of these diseases or to what extent different model systems and routes of infection influenced the relative levels of expression. Similarly, it was not clear whether the elevated levels of cytokines observed in the brain were accompanied by similar increases in other tissues that accumulate PrPres, such as the spleen. Results The level of expression of the three interferon responsive genes, Eif2ak2, 2'5'-OAS, and Mx2, was measured in the brains of Syrian hamsters infected with scrapie 263K, VM mice infected with bovine spongiform encephalopathy and C57BL/6 mice infected with the scrapie strain ME7. Glial fibrillary acidic expression confirmed the occurrence of astrocytosis in all models. When infected intracranially all three models showed a similar pattern of increased expression of the interferon responsive genes at the onset of clinical symptoms. At the terminal stage of the disease the level and pattern of expression of the three genes was mostly unchanged in the mouse models. In contrast, in hamsters infected by either the intracranial or intraperitoneal routes, both the level of expression and the expression of the three genes relative to one another was altered. Increased interferon responsive gene expression was not observed in a transgenic mouse model of Alzheimer's disease or the spleens of C57BL/6 mice infected with ME7. Concurrent increases in TNFα, TNFR1, Fas/ApoI receptor, and caspase 8 expression in ME7 infected C57BL/6 mice were observed. Conclusion The identification of increased interferon responsive gene expression in the brains of three rodent models of TSE disease at two different stages of disease progression suggest that this may be a general feature of the disease in rodents. In addition, it was determined that the increased interferon responsive gene expression was confined to the CNS and that the TSE model system and the route of infection influenced the pattern and extent of the increased expression. The concurrent increase in initiators of Eif2ak2 mediated apoptotic pathways in C57BL/6 mice infected with ME7 suggested one mechanism by which increased interferon responsive gene expression may enhance disease progression.
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Affiliation(s)
- Michael J Stobart
- Division of Host Genetics and Prion Diseases, Public Health Agency of Canada, Canadian Science Centre for Human and Animal Health, Winnipeg, MB R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0W3, Canada
| | - Debra Parchaliuk
- Division of Host Genetics and Prion Diseases, Public Health Agency of Canada, Canadian Science Centre for Human and Animal Health, Winnipeg, MB R3E 3R2, Canada
| | - Sharon LR Simon
- Division of Host Genetics and Prion Diseases, Public Health Agency of Canada, Canadian Science Centre for Human and Animal Health, Winnipeg, MB R3E 3R2, Canada
| | - Jillian LeMaistre
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0W3, Canada
| | - Jozef Lazar
- Department of Dermatology and Human Molecular Genetics Center, MCW, Milwaukee, WI 53226, USA
| | - Richard Rubenstein
- Department of Biochemistry, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
| | - J David Knox
- Division of Host Genetics and Prion Diseases, Public Health Agency of Canada, Canadian Science Centre for Human and Animal Health, Winnipeg, MB R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, Faculty of Medicine, University of Manitoba, Winnipeg, MB R3E 0W3, Canada
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27
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Müller H, Stitz L, Riesner D. Risk assessment for fat derivatives in case of contamination with BSE. EUR J LIPID SCI TECH 2006. [DOI: 10.1002/ejlt.200600068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Appel TR, Lucassen R, Groschup MH, Joncic M, Beekes M, Riesner D. Acid inactivation of prions: efficient at elevated temperature or high acid concentration. J Gen Virol 2006; 87:1385-1394. [PMID: 16603542 DOI: 10.1099/vir.0.81426-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scrapie prion rods isolated from hamster and non-infectious aggregates of the corresponding recombinant protein rPrP(90–231) were incubated with hydrochloric acid. The amount of PrP and of infectivity that survived incubation in HCl at varying times, acid concentrations and temperatures was quantified by Western blot densitometry and bioassays, respectively. Prion rods and rPrP aggregates showed similar HCl hydrolysis kinetics of PrP, indicating structural homology. For 1 M HCl and 25 °C, the rate of PrP hydrolysis follows first-order kinetics at 0·014 h−1; the rate of infectivity inactivation is 0·54 h−1. Hydrolysis for 1 h at 25 °C was only slightly proportional to HCl concentration up to 5 M, but complete loss of infectivity and PrP reduction to <2 % was observed at 8 M HCl. The temperature dependence of unhydrolysed PrP, as well as infectivity at 1 M HCl for 1 h, showed a slight decrease up to 45 °C, but a sigmoidal decrease by several orders of magnitude at higher temperatures. The slow hydrolysis of PrP and inactivation of infectivity by acid treatment at room temperature are attributed to solvent inaccessibility of prion rods and rPrP aggregates, respectively. The more effective hydrolysis and inactivation at temperatures above 45 °C are interpreted as thermally induced disaggregation with an activation energy of 50–60 kJ mol−1. Most importantly, infectivity was always inactivated faster or to a higher extent than PrP was hydrolysed at several incubation times, HCl concentrations and temperatures.
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Affiliation(s)
- Thomas R Appel
- Institut für Physikalische Biologie, Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität Düsseldorf, Gebäude 26.12, D-40225 Düsseldorf, Germany
- IMB, Leibniz Institut für Molekulare Biotechnologie Jena eV, Jena, Germany
| | - Ralf Lucassen
- Institut für Physikalische Biologie, Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität Düsseldorf, Gebäude 26.12, D-40225 Düsseldorf, Germany
| | | | | | | | - Detlev Riesner
- Institut für Physikalische Biologie, Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität Düsseldorf, Gebäude 26.12, D-40225 Düsseldorf, Germany
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29
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Yao HL, Han J, Gao JM, Zhang J, Zhang BY, Guo YJ, Nie K, Gao C, Wang XF, Dong XP. Comparative study of the effects of several chemical and physical treatments on the activity of protease resistance and infectivity of scrapie strain 263K. ACTA ACUST UNITED AC 2006; 52:437-43. [PMID: 16364019 DOI: 10.1111/j.1439-0450.2005.00897.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To study the influences of chemical and physical factors on the protease resistant activity in vitro and the infectivity in vivo of scrapie strain 263K, PrPSc from the hamsters infected intracerebrally with scrapie strain 263K were treated with several commonly used disinfection methods, including sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), heating or autoclaving at 80, 100, 121 and 134 degrees C in the solutions with or without 3% sodium dodecyl sulphate (SDS). The protease resistance of PrPSc was analysed by a proteinase K (PK) digesting Western blot and the infectivity of PrPSc was analysed by intracerebral (i.c.) inoculation into experimental hamsters. The results showed that PrPSc signals were removed in the preparations treated with NaOH higher than 0.05 mol/l, NaOCl higher than 0.1%, autoclaved over 121 degrees C, or heated over 80 degrees C in the presence of 3% SDS. Animal challenges revealed that mixing with 2 mol/l NaOH or 2% NaOCl, autoclaving at 134 degrees C, as well as heating at 100 degrees C or autoclaving at 121 degrees C in the solutions with 3% SDS completely blocks the transmission of scrapie 263K in this experimental situation. It is obvious that the removal of PK resistance of PrPSc happened at relatively lower concentration chemicals or lower temperature, while elimination of the infectivity needs more vigorous conditions. Our data provide the useful evidences for several commonly used methods to inactivate TSEs agent and suggest that it is inappropriate to use PrPSc as a surrogate for TSEs infectivity in inactivation experiments.
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Affiliation(s)
- H-L Yao
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Ying-Xin Rd 100, Beijing 100052
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30
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Tayebi M, Enever P, Sattar Z, Collinge J, Hawke S. Disease-associated prion protein elicits immunoglobulin M responses in vivo. Mol Med 2006; 10:104-11. [PMID: 15706401 PMCID: PMC1431372 DOI: 10.2119/2004-00027.tayebi] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Accepted: 11/03/2004] [Indexed: 11/06/2022] Open
Abstract
Prion diseases such as Creutzfeldt-Jakob disease are believed to result from the misfolding of a widely expressed normal cellular prion protein, PrPc. The resulting disease-associated isoforms, PrP(Sc), have much higher beta-sheet content, are insoluble in detergents, and acquire relative resistance to proteases. Although known to be highly aggregated and to form amyloid fibrils, the molecular architecture of PrP9Sc) is poorly understood. To date, it has been impossible to elicit antibodies to native PrP(Sc) that are capable of recognizing PrP(Sc) without denaturation, even in Pm-P(o/o) mice that are intolerant of it. Here we demonstrate that antibodies for native PrPc and PrP(Sc) can be produced by immunization of Pm-P(o/o) mice with partially purified PrPc and PrP(Sc) adsorbed to immunomagnetic particles using high-affinity anti-PrP monoclonal antibodies (mAbs). Interestingly, the polyclonal response to PrP(Sc) was predominantly of the immunoglobulin M (IgM) isotype, unlike the immunoglobulin G (IgG) responses elicited by PrP(c) or by recombinant PrP adsorbed or not to immunomagnetic particles, presumably reflecting the polymeric structure of disease-associated prion protein. Although heat-denatured PrP(Sc) elicited more diverse antibodies with the revelation of C-terminal epitopes, remarkably, these were also predominantly IgM suggesting that the increasing immunogenicity, acquisition of protease sensitivity, and reduction in infectivity induced by heat are not associated with dissociation of the PrP molecules in the diseased-associated protein. Adsorbing native proteins to immunomagnetic particles may have general applicability for raising polyclonal or monoclonal antibodies to any native protein, without attempting laborious purification steps that might affect protein conformation.
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Affiliation(s)
- Mourad Tayebi
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London, UK
- Department of Neurogenetics, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College, Norfolk Place, London, UK
| | - Perry Enever
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London, UK
| | - Zahid Sattar
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London, UK
| | - John Collinge
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London, UK
- Department of Neurogenetics, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College, Norfolk Place, London, UK
| | - Simon Hawke
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London, UK
- Department of Neurogenetics, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College, Norfolk Place, London, UK
- Address correspondence and reprint requests to Simon Hawke, Department of Medicine, The University of Sydney, Blackburn Building D06, NSW 2006, Australia. Phone: +61-263620711; fax: + 61-263620129; e-mail:
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Abstract
Risk assessments for bovine spongiform encephalopathy (BSE) should be based on the group risk and not the median individual risk. The group risk is calculated from the arithmetic mean risk, which in the case of dorsal root ganglia, is a factor of 50-fold higher than the median. For environmental routes, the arithmetic mean exposure is sufficient for risk assessment, while for food-borne routes failure to accommodate the variation in exposures to individuals across the UK population could overestimate the group risk considerably. Ignoring prion destruction by cooking could overestimate the food-borne risks still further. The recent estimate for the arithmetic mean cow-to-man species barrier of 4000 does not take into accounts either of these factors and thus may be too high. Until evidence for a threshold dose is demonstrated, public health scientists should avoid assessing safety on the basis of a 'minimum infective dose'. The incubation period observed in cattle-feeding studies, when completed, would continue to increase with decreasing dose below the ID50if there is a threshold or co-operative effect. The question is raised of whether fears over BSE in drinking water contributed to the spread of foot-and-mouth disease across the UK in 2001; a risk tradeoff.
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Peretz D, Supattapone S, Giles K, Vergara J, Freyman Y, Lessard P, Safar JG, Glidden DV, McCulloch C, Nguyen HOB, Scott M, Dearmond SJ, Prusiner SB. Inactivation of prions by acidic sodium dodecyl sulfate. J Virol 2006; 80:322-31. [PMID: 16352557 PMCID: PMC1317507 DOI: 10.1128/jvi.80.1.322-331.2006] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Accepted: 09/16/2005] [Indexed: 11/20/2022] Open
Abstract
Prompted by the discovery that prions become protease-sensitive after exposure to branched polyamine dendrimers in acetic acid (AcOH) (S. Supattapone, H. Wille, L. Uyechi, J. Safar, P. Tremblay, F. C. Szoka, F. E. Cohen, S. B. Prusiner, and M. R. Scott, J. Virol. 75:3453-3461, 2001), we investigated the inactivation of prions by sodium dodecyl sulfate (SDS) in weak acid. As judged by sensitivity to proteolytic digestion, the disease-causing prion protein (PrPSc) was denatured at room temperature by SDS at pH values of < or =4.5 or > or =10. Exposure of Sc237 prions in Syrian hamster brain homogenates to 1% SDS and 0.5% AcOH at room temperature resulted in a reduction of prion titer by a factor of ca. 10(7); however, all of the bioassay hamsters eventually developed prion disease. When various concentrations of SDS and AcOH were tested, the duration and temperature of exposure acted synergistically to inactivate both hamster Sc237 prions and human sporadic Creutzfeldt-Jakob disease (sCJD) prions. The inactivation of prions in brain homogenates and those bound to stainless steel wires was evaluated by using bioassays in transgenic mice. sCJD prions were more than 100,000 times more resistant to inactivation than Sc237 prions, demonstrating that inactivation procedures validated on rodent prions cannot be extrapolated to inactivation of human prions. Some procedures that significantly reduced prion titers in brain homogenates had a limited effect on prions bound to the surface of stainless steel wires. Using acidic SDS combined with autoclaving for 15 min, human sCJD prions bound to stainless steel wires were eliminated. Our findings form the basis for a noncorrosive system that is suitable for inactivating prions on surgical instruments, as well as on other medical and dental equipment.
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Affiliation(s)
- David Peretz
- Institute for Neurodegenerative Diseases, 513 Parnassus Ave., HSE-774, San Francisco, CA 94143-0518, USA
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33
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Jackson GS, McKintosh E, Flechsig E, Prodromidou K, Hirsch P, Linehan J, Brandner S, Clarke AR, Weissmann C, Collinge J. An enzyme-detergent method for effective prion decontamination of surgical steel. J Gen Virol 2005; 86:869-878. [PMID: 15722550 DOI: 10.1099/vir.0.80484-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Prions, transmissible agents that cause Creutzfeldt-Jakob disease (CJD) and other prion diseases, are known to resist conventional sterilization procedures. Iatrogenic transmission of classical CJD via neurosurgical instruments is well documented and the involvement of lymphoreticular tissues in variant CJD (vCJD), together with the unknown population prevalence of asymptomatic vCJD infection, has led to concerns about transmission from a wide range of surgical procedures. To address this problem, conditions were sought that destroy PrP(Sc) from vCJD-infected human tissue and eradicate RML prion infectivity adsorbed onto surgical steel. Seven proteolytic enzymes were evaluated individually and in pairs at a range of temperatures and pH values and the additional effects of detergents, lipases and metal ions were assessed. A combination of proteinase K and Pronase, in conjunction with SDS, was shown to degrade PrP(Sc) material from highly concentrated vCJD-infected brain preparations to a level below detection. When RML prion-infected wires were exposed to the same enzymic treatment, intracerebral bioassay in highly susceptible hosts showed virtually no infectivity. The prion-degrading reagents identified in this study are readily available, inexpensive, non-corrosive to instruments, non-hazardous to staff and compatible with current equipment and procedures used in hospital sterilization units.
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Affiliation(s)
- Graham S Jackson
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Edward McKintosh
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Eckhard Flechsig
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Kanella Prodromidou
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Petra Hirsch
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Jackie Linehan
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Sebastian Brandner
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Anthony R Clarke
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Charles Weissmann
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
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Legname G, Nguyen HOB, Baskakov IV, Cohen FE, Dearmond SJ, Prusiner SB. Strain-specified characteristics of mouse synthetic prions. Proc Natl Acad Sci U S A 2005; 102:2168-73. [PMID: 15671162 PMCID: PMC548557 DOI: 10.1073/pnas.0409079102] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Synthetic prions were produced in our laboratory by using recombinant mouse prion protein (MoPrP) composed of residues 89-230. The first mouse synthetic prion strain (MoSP1) was inoculated into transgenic (Tg) 9949 mice expressing N-terminally truncated MoPrP(Delta23-88) and WT FVB mice expressing full-length MoPrP. On first and second passage in Tg9949 mice, MoSP1 prions caused disease in 516 +/- 27 and 258 +/- 25 days, respectively; numerous, large vacuoles were found in the brainstem and gray matter of the cerebellum. MoSP1 prions passaged in Tg9949 mice were inoculated into FVB mice; on first and second passage, the FVB mice exhibited incubation times of 154 +/- 4 and 130 +/- 3 days, respectively. In FVB mice, vacuolation was less intense but more widely distributed, with numerous lesions in the hippocampus and cerebellar white matter. This constellation of widespread neuropatho-logic changes was similar to that found in FVB mice inoculated with Rocky Mountain Laboratory (RML) prions, a strain derived from a sheep with scrapie. Conformational stability studies showed that the half-maximal GdnHCl (Gdn1/2) concentration for denaturation of MoSP1 prions passaged in Tg9949 mice was approximately 4.2 M; passage in FVB mice reduced the Gdn1/2 value to approximately 1.7 M. RML prions passaged in either Tg9949 or FVB mice exhibited Gdn1/2 values of approximately 1.8 M. The incubation times, neuropathological lesion profiles, and Gdn1/2 values indicate that MoSP1 prions differ from RML and many other prion strains derived from sheep with scrapie and cattle with bovine spongiform encephalopathy.
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Affiliation(s)
- Giuseppe Legname
- Institute for Neurodegenerative Diseases , University of California, San Francisco, CA 94143, USA
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Brown P, Rau EH, Lemieux P, Johnson BK, Bacote AE, Gajdusek DC. Infectivity studies of both ash and air emissions from simulated incineration of scrapie-contaminated tissues. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2004; 38:6155-6160. [PMID: 15575075 DOI: 10.1021/es040301z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We investigated the effectiveness of 15 min exposures to 600 and 1000 degrees C in continuous flow normal and starved-air incineration-like conditions to inactivate samples of pooled brain macerates from hamsters infected with the 263K strain of hamster-adapted scrapie with an infectivity titer in excess of 10(9) mean lethal doses (LD50) per g. Bioassays of the ash, outflow tubing residues, and vented emissions from heating 1 g of tissue samples yielded a total of two transmissions among 21 inoculated animals from the ash of a single specimen burned in normal air at 600 degrees C. No other ash, residue, or emission from samples heated at either 600 or 1000 degrees C, under either normal or starved-air conditions, transmitted disease. We conclude that at temperatures approaching 1000 degrees C under the air conditions and combustion times used in these experiments, contaminated tissues can be completely inactivated, with no release of infectivity into the environment from emissions. The extent to which this result can be realized in actual incinerators and other combustion devices will depend on equipment design and operating conditions during the heating process.
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Affiliation(s)
- Paul Brown
- Laboratory of CNS Studies, National Institute of Neurological Disorders and Stroke, and Div. of Environmental Protection, Office of Research Facilities Development and Operations, NIH, US Dept. of HHS, Bethesda, MD 20892, USA.
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McLeod AH, Murdoch H, Dickinson J, Dennis MJ, Hall GA, Buswell CM, Carr J, Taylor DM, Sutton JM, Raven NDH. Proteolytic inactivation of the bovine spongiform encephalopathy agent. Biochem Biophys Res Commun 2004; 317:1165-70. [PMID: 15094392 DOI: 10.1016/j.bbrc.2004.03.168] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Indexed: 11/17/2022]
Abstract
Thermostable proteases have been investigated for their ability to provide a novel biological solution to decontamination of prion agents responsible for transmissible spongiform encephalopathies (TSEs). Proteases were identified that digested total mouse brain homogenate (MBH) protein from uninfected mice. These proteases were then evaluated for digestion of BSE (301V) infectious MBH over a range of pH and temperatures, screened for loss of anti-prion antibody 6H4 immunoreactivity and protease-treated infectious MBH assessed in mouse bioassay using VM mice. Despite a number of proteases eliminating all 6H4-immunoreactive material, only the subtilisin-enzyme Properase showed a significant extension in incubation period in mouse bioassays following a 30-min incubation at 60 degrees C and pH 12. These results demonstrate the potential of the method to provide a practical solution to the problems of TSE contamination of surgical instruments and highlight the inadequacy of using Western blot for assessment of decontamination/inactivation of TSE agents.
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Affiliation(s)
- Anne H McLeod
- Health Protection Agency, Porton Down, Salisbury, Wiltshire SP4 0JG, UK
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Abstract
The molecular structures of the infectious agents that cause transmissible spongiform encephalopathy (TSE) diseases are still not known despite the current wide acceptance of the prion hypothesis as the basis for their resolution. Here, data supporting and challenging the prion hypothesis in relation to both the biochemical and biological properties of TSE infectious agents are discussed. The need for the independent transmission of TSE agent-specific genetic information is described and the requirements for the molecule to carry this information are proposed. Such a molecule is likely to be a small nucleic acid encoding information to determine the diversity of the pathogenesis of TSE agents.
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Affiliation(s)
- Robert A Somerville
- Neuropathogenesis Unit, Institute for Animal Health, West Mains Road, Edinburgh, Scotland, UK, EH9 3JF.
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