1
|
Marín-Moreno A, Benestad SL, Barrio T, Pirisinu L, Espinosa JC, Tran L, Huor A, Di Bari MA, Eraña H, Maddison BC, D'Agostino C, Fernández-Borges N, Canoyra S, Jerez-Garrido N, Castilla J, Spiropoulos J, Bishop K, Gough KC, Nonno R, Våge J, Andréoletti O, Torres JM. Classical BSE dismissed as the cause of CWD in Norwegian red deer despite strain similarities between both prion agents. Vet Res 2024; 55:62. [PMID: 38750594 PMCID: PMC11097568 DOI: 10.1186/s13567-024-01320-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/16/2024] [Indexed: 05/18/2024] Open
Abstract
The first case of CWD in a Norwegian red deer was detected by a routine ELISA test and confirmed by western blotting and immunohistochemistry in the brain stem of the animal. Two different western blotting tests were conducted independently in two different laboratories, showing that the red deer glycoprofile was different from the Norwegian CWD reindeer and CWD moose and from North American CWD. The isolate showed nevertheless features similar to the classical BSE (BSE-C) strain. Furthermore, BSE-C could not be excluded based on the PrPSc immunohistochemistry staining in the brainstem and the absence of detectable PrPSc in the lymphoid tissues. Because of the known ability of BSE-C to cross species barriers as well as its zoonotic potential, the CWD red deer isolate was submitted to the EURL Strain Typing Expert Group (STEG) as a BSE-C suspect for further investigation. In addition, different strain typing in vivo and in vitro strategies aiming at identifying the BSE-C strain in the red deer isolate were performed independently in three research groups and BSE-C was not found in it. These results suggest that the Norwegian CWD red deer case was infected with a previously unknown CWD type and further investigation is needed to determine the characteristics of this potential new CWD strain.
Collapse
Affiliation(s)
- Alba Marín-Moreno
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | | | - Tomas Barrio
- UMR École Nationale Vétérinaire de Toulouse (ENVT), 1225 Interactions Hôtes-Agents Pathogènes, Institut National Pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Toulouse, France
| | - Laura Pirisinu
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Juan Carlos Espinosa
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Linh Tran
- Norwegian Veterinary Institute, Ås, Norway
| | - Alvina Huor
- UMR École Nationale Vétérinaire de Toulouse (ENVT), 1225 Interactions Hôtes-Agents Pathogènes, Institut National Pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Toulouse, France
| | - Michele Angelo Di Bari
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Hasier Eraña
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Basque Foundation for Science, Bizkaia Technology Park & IKERBASQUE, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, Madrid, Spain
| | - Ben C Maddison
- RSK- ADAS Ltd, Technology Drive, Beeston, Nottingham, UK
| | - Claudia D'Agostino
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Natalia Fernández-Borges
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Sara Canoyra
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Nuria Jerez-Garrido
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Joaquín Castilla
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Basque Foundation for Science, Bizkaia Technology Park & IKERBASQUE, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, Madrid, Spain
| | | | - Keith Bishop
- RSK- ADAS Ltd, Technology Drive, Beeston, Nottingham, UK
| | | | - Romolo Nonno
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Jorn Våge
- Norwegian Veterinary Institute, Ås, Norway
| | - Olivier Andréoletti
- UMR École Nationale Vétérinaire de Toulouse (ENVT), 1225 Interactions Hôtes-Agents Pathogènes, Institut National Pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Toulouse, France
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
| |
Collapse
|
2
|
Koutsoumanis K, Allende A, Alvarez‐Ordoñez A, Bolton D, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Skandamis P, Suffredini E, Miller MW, Mysterud A, Nöremark M, Simmons M, Tranulis MA, Vaccari G, Viljugrein H, Ortiz‐Pelaez A, Ru G. Monitoring of chronic wasting disease (CWD) (IV). EFSA J 2023; 21:e07936. [PMID: 37077299 PMCID: PMC10107390 DOI: 10.2903/j.efsa.2023.7936] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023] Open
Abstract
The European Commission requested an analysis of the Chronic Wasting Disease (CWD) monitoring programme in Norway, Sweden, Finland, Iceland, Estonia, Latvia, Lithuania and Poland (9 January 2017-28 February 2022). Thirteen cases were detected in reindeer, 15 in moose and 3 in red deer. They showed two phenotypes, distinguished by the presence or absence of detectable disease-associated normal cellular prion protein (PrP) in lymphoreticular tissues. CWD was detected for the first time in Finland, Sweden and in other areas of Norway. In countries where the disease was not detected, the evidence was insufficient to rule out its presence altogether. Where cases were detected, the prevalence was below 1%. The data also suggest that the high-risk target groups for surveillance should be revised, and 'road kill' removed. Data show that, in addition to differences in age and sex, there are differences in the prion protein gene (PRNP) genotypes between positive and negative wild reindeer. A stepwise framework has been proposed with expanded minimum background surveillance to be implemented in European countries with relevant cervid species. Additional surveillance may include ad hoc surveys for four different objectives, specific to countries with/without cases, focusing on parallel testing of obex and lymph nodes from adult cervids in high-risk target groups, sustained over time, using sampling units and a data-driven design prevalence. Criteria for assessing the probability of CWD presence have been outlined, based on the definition of the geographical area, an annual assessment of risk of introduction, sustained minimum background surveillance, training and engagement of stakeholders and a surveillance programme based on data-driven parameters. All positive cases should be genotyped. Sample sizes for negative samples have been proposed to detect and estimate the frequency of PRNP polymorphisms. Double-strand sequencing of the entire PRNP open reading frame should be undertaken for all selected samples, with data collated in a centralised collection system at EU level.
Collapse
|
3
|
Tranulis MA, Tryland M. The Zoonotic Potential of Chronic Wasting Disease-A Review. Foods 2023; 12:foods12040824. [PMID: 36832899 PMCID: PMC9955994 DOI: 10.3390/foods12040824] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Prion diseases are transmissible neurodegenerative disorders that affect humans and ruminant species consumed by humans. Ruminant prion diseases include bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep and goats and chronic wasting disease (CWD) in cervids. In 1996, prions causing BSE were identified as the cause of a new prion disease in humans; variant Creutzfeldt-Jakob disease (vCJD). This sparked a food safety crisis and unprecedented protective measures to reduce human exposure to livestock prions. CWD continues to spread in North America, and now affects free-ranging and/or farmed cervids in 30 US states and four Canadian provinces. The recent discovery in Europe of previously unrecognized CWD strains has further heightened concerns about CWD as a food pathogen. The escalating CWD prevalence in enzootic areas and its appearance in a new species (reindeer) and new geographical locations, increase human exposure and the risk of CWD strain adaptation to humans. No cases of human prion disease caused by CWD have been recorded, and most experimental data suggest that the zoonotic risk of CWD is very low. However, the understanding of these diseases is still incomplete (e.g., origin, transmission properties and ecology), suggesting that precautionary measures should be implemented to minimize human exposure.
Collapse
Affiliation(s)
- Michael A. Tranulis
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 5003 As, Norway
- Correspondence: ; Tel.: +47-67232040
| | - Morten Tryland
- Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, 2480 Koppang, Norway
| |
Collapse
|
4
|
Silva CJ. Chronic Wasting Disease (CWD) in Cervids and the Consequences of a Mutable Protein Conformation. ACS OMEGA 2022; 7:12474-12492. [PMID: 35465121 PMCID: PMC9022204 DOI: 10.1021/acsomega.2c00155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/18/2022] [Indexed: 05/15/2023]
Abstract
Chronic wasting disease (CWD) is a prion disease of cervids (deer, elk, moose, etc.). It spreads readily from CWD-contaminated environments and among wild cervids. As of 2022, North American CWD has been found in 29 states, four Canadian provinces and South Korea. The Scandinavian form of CWD originated independently. Prions propagate their pathology by inducing a natively expressed prion protein (PrPC) to adopt the prion conformation (PrPSc). PrPC and PrPSc differ solely in their conformation. Like other prion diseases, transmissible CWD prions can arise spontaneously. The CWD prions can respond to selection pressures resulting in the emergence of new strain phenotypes. Annually, 11.5 million Americans hunt and harvest nearly 6 million deer, indicating that CWD is a potential threat to an important American food source. No tested CWD strain has been shown to be zoonotic. However, this may not be true for emerging strains. Should a zoonotic CWD strain emerge, it could adversely impact the hunting economy and game meat consumers.
Collapse
Affiliation(s)
- Christopher J. Silva
- Produce Safety & Microbiology
Research Unit, Western Regional Research Center, Agricultural Research
Service, United States Department of Agriculture, Albany, California 94710, United States of America
| |
Collapse
|
5
|
Transport of Prions in the Peripheral Nervous System: Pathways, Cell Types, and Mechanisms. Viruses 2022; 14:v14030630. [PMID: 35337037 PMCID: PMC8954800 DOI: 10.3390/v14030630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 01/27/2023] Open
Abstract
Prion diseases are transmissible protein misfolding disorders that occur in animals and humans where the endogenous prion protein, PrPC, undergoes a conformational change into self-templating aggregates termed PrPSc. Formation of PrPSc in the central nervous system (CNS) leads to gliosis, spongiosis, and cellular dysfunction that ultimately results in the death of the host. The spread of prions from peripheral inoculation sites to CNS structures occurs through neuroanatomical networks. While it has been established that endogenous PrPC is necessary for prion formation, and that the rate of prion spread is consistent with slow axonal transport, the mechanistic details of PrPSc transport remain elusive. Current research endeavors are primarily focused on the cellular mechanisms of prion transport associated with axons. This includes elucidating specific cell types involved, subcellular machinery, and potential cofactors present during this process.
Collapse
|
6
|
Matsuura Y, Miyazawa K, Horiuchi M, Suzuki A, Yokoyama M, Imamura M, Ikeda K, Iwamaru Y. Extended application of the rapid post-mortem test kit for bovine spongiform encephalopathy to chronic wasting disease. Microbiol Immunol 2022; 66:212-215. [PMID: 35141940 DOI: 10.1111/1348-0421.12968] [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: 11/28/2021] [Revised: 01/17/2022] [Accepted: 02/04/2022] [Indexed: 11/28/2022]
Abstract
Chronic wasting disease (CWD) is a prion disease affecting cervid species primarily in the United States of America and Canada; however, it is now emerging in Scandinavian countries. Although CWD cases have not been reported in Japan, in case of a CWD outbreak, it is critical to prepare for testing a large number of specimens. In the present study, we showed that a rapid post-mortem test kit, which is used for bovine spongiform encephalopathy surveillance in Japan, is valid for CWD prion detection. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Yuichi Matsuura
- Division of Infectious Animal Diseases, National Institute of Animal Health, Ibaraki, 305-0856, Japan
| | - Kohtaro Miyazawa
- Division of Infectious Animal Diseases, National Institute of Animal Health, Ibaraki, 305-0856, Japan
| | - Motohiro Horiuchi
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Graduate School of Infectious Diseases, and One Health Research Center, Hokkaido University, Hokkaido, 060-0818, Japan
| | - Akio Suzuki
- Laboratory of Veterinary Hygiene, Faculty of Veterinary Medicine, Graduate School of Infectious Diseases, and One Health Research Center, Hokkaido University, Hokkaido, 060-0818, Japan
| | - Mayumi Yokoyama
- Institute of Natural and Environmental Sciences University of Hyogo / Wildlife Management Research Center, Hyogo, 669-3842, Japan
| | - Morikazu Imamura
- Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan
| | - Keigo Ikeda
- Division of Infectious Animal Diseases, National Institute of Animal Health, Ibaraki, 305-0856, Japan
| | - Yoshifumi Iwamaru
- Division of Infectious Animal Diseases, National Institute of Animal Health, Ibaraki, 305-0856, Japan
| |
Collapse
|
7
|
Tranulis MA, Gavier-Widén D, Våge J, Nöremark M, Korpenfelt SL, Hautaniemi M, Pirisinu L, Nonno R, Benestad SL. Chronic wasting disease in Europe: new strains on the horizon. Acta Vet Scand 2021; 63:48. [PMID: 34823556 PMCID: PMC8613970 DOI: 10.1186/s13028-021-00606-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 09/30/2021] [Indexed: 01/05/2023] Open
Abstract
Prion diseases are fatal neurodegenerative disorders with known natural occurrence in humans and a few other mammalian species. The diseases are experimentally transmissible, and the agent is derived from the host-encoded cellular prion protein (PrPC), which is misfolded into a pathogenic conformer, designated PrPSc (scrapie). Aggregates of PrPSc molecules, constitute proteinaceous infectious particles, known as prions. Classical scrapie in sheep and goats and chronic wasting disease (CWD) in cervids are known to be infectious under natural conditions. In CWD, infected animals can shed prions via bodily excretions, allowing direct host-to-host transmission or indirectly via prion-contaminated environments. The robustness of prions means that transmission via the latter route can be highly successful and has meant that limiting the spread of CWD has proven difficult. In 2016, CWD was diagnosed for the first time in Europe, in reindeer (Rangifer tarandus) and European moose (Alces alces). Both were diagnosed in Norway, and, subsequently, more cases were detected in a semi-isolated wild reindeer population in the Nordfjella area, in which the first case was identified. This population was culled, and all reindeer (approximately 2400) were tested for CWD; 18 positive animals, in addition to the first diagnosed case, were found. After two years and around 25,900 negative tests from reindeer (about 6500 from wild and 19,400 from semi-domesticated) in Norway, a new case was diagnosed in a wild reindeer buck on Hardangervidda, south of the Nordfjella area, in 2020. Further cases of CWD were also identified in moose, with a total of eight in Norway, four in Sweden, and two cases in Finland. The mean age of these cases is 14.7 years, and the pathological features are different from North American CWD and from the Norwegian reindeer cases, resembling atypical prion diseases such as Nor98/atypical scrapie and H- and L-forms of BSE. In this review, these moose cases are referred to as atypical CWD. In addition, two cases were diagnosed in red deer (Cervus elaphus) in Norway. The emergence of CWD in Europe is a threat to European cervid populations, and, potentially, a food-safety challenge, calling for a swift, evidence-based response. Here, we review data on surveillance, epidemiology, and disease characteristics, including prion strain features of the newly identified European CWD agents.
Collapse
|
8
|
Moazami-Goudarzi K, Andréoletti O, Vilotte JL, Béringue V. Review on PRNP genetics and susceptibility to chronic wasting disease of Cervidae. Vet Res 2021; 52:128. [PMID: 34620247 PMCID: PMC8499490 DOI: 10.1186/s13567-021-00993-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/10/2021] [Indexed: 12/17/2022] Open
Abstract
To date, chronic wasting disease (CWD) is the most infectious form of prion disease affecting several captive, free ranging and wild cervid species. Responsible for marked population declines in North America, its geographical spread is now becoming a major concern in Europe. Polymorphisms in the prion protein gene (PRNP) are an important factor influencing the susceptibility to prions and their rate of propagation. All reported cervid PRNP genotypes are affected by CWD. However, in each species, some polymorphisms are associated with lower attack rates and slower progression of the disease. This has potential consequences in terms of genetic selection, CWD diffusion and strain evolution. CWD also presents a zoonotic risk due to prions capacity to cross species barriers. This review summarizes our current understanding of CWD control, focusing on PRNP genetic, strain diversity and capacity to infect other animal species, including humans.
Collapse
Affiliation(s)
| | - Olivier Andréoletti
- UMR INRAE ENVT 1225 - IHAP, École Nationale Vétérinaire de Toulouse, 31076, Toulouse, France
| | - Jean-Luc Vilotte
- University Paris-Saclay, INRAE, AgroParisTech, GABI, 78350, Jouy-en-Josas, France
| | - Vincent Béringue
- University Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| |
Collapse
|
9
|
Güere ME, Våge J, Tharaldsen H, Kvie KS, Bårdsen BJ, Benestad SL, Vikøren T, Madslien K, Rolandsen CM, Tranulis MA, Røed KH. Chronic wasting disease in Norway-A survey of prion protein gene variation among cervids. Transbound Emerg Dis 2021; 69:e20-e31. [PMID: 34346562 DOI: 10.1111/tbed.14258] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 11/29/2022]
Abstract
Susceptibility of cervids to Chronic Wasting Disease (CWD), a prion disease, can be modulated by variations in the prion protein gene (PRNP), encoding the cellular prion protein (PrPC ). In prion diseases, PrPC is conformationally converted to pathogenic conformers (PrPSc ), aggregates of which comprise infectious prions. CWD has recently been observed in its contagious form in Norwegian reindeer (Rangifer tarandus) and in novel, potentially sporadic forms, here called 'atypical CWD', in moose (Alces alces) and red deer (Cervus elaphus). To estimate relative susceptibility of different Norwegian cervid species to CWD, their non-synonymous PRNP variants were analyzed. In reindeer, seven PRNP alleles were observed and in red deer and moose two alleles were present, whereas roe deer (Capreolus capreolus) PRNP was monomorphic. One 'archetypal' PRNP allele associated with susceptibility was common to all four cervid species. The distribution of PRNP alleles differed between wild and semi-domesticated reindeer, with alleles associated with a high susceptibility occurring, on average, above 55% in wild reindeer and below 20% in semi-domesticated reindeer. This difference may reflect the diverse origins of the populations and/or selection processes during domestication and breeding. Overall, PRNP genetic data indicate considerable susceptibility to CWD among Norwegian cervids and suggest that PRNP homozygosity may be a risk factor for the atypical CWD observed in moose. The CWD isolates found in the Norwegian cervid species differ from those previously found in Canada and USA. Our study provides an overview of the PRNP genetics in populations exposed to these emerging strains that will provide a basis for understanding these strains' dynamics in relation to PRNP variability.
Collapse
Affiliation(s)
- Mariella Evelyn Güere
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Jørn Våge
- Norwegian Veterinary Institute, OIE Reference Laboratory for CWD, Ås, Norway
| | - Helene Tharaldsen
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Kjersti Sternang Kvie
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Bård-Jørgen Bårdsen
- Arctic Ecology Department, Fram Centre, Norwegian Institute for Nature Research, Tromsø, Norway
| | | | - Turid Vikøren
- Norwegian Veterinary Institute, OIE Reference Laboratory for CWD, Ås, Norway
| | - Knut Madslien
- Norwegian Veterinary Institute, OIE Reference Laboratory for CWD, Ås, Norway
| | - Christer Moe Rolandsen
- Terrestrial Ecology Department, Norwegian Institute for Nature Research, Trondheim, Norway
| | - Michael Andreas Tranulis
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Knut Håkon Røed
- Department of Preclinical Sciences and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| |
Collapse
|
10
|
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] [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.
Collapse
|