1
|
Mathiason CK. Scrapie, CWD, and Transmissible Mink Encephalopathy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:267-292. [PMID: 28838664 DOI: 10.1016/bs.pmbts.2017.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs), or prions, are neurodegenerative diseases that affect a variety of animal species, including humans. Cruetzfeldt-Jakob disease (CJD) in humans, sheep and goat scrapie, chronic wasting disease (CWD) of cervids, and transmissible mink encephalopathy (TME) of mink are classified as TSEs. According to the "protein-only" hypothesis (Prusiner, 1982),1 prions are devoid of nucleic acids and consist of assemblies of misfolded host-encoded normal protein, the prion protein (PrPC). Prion propagation is thought to occur by a templating mechanism during which PrPC is recruited, converted to a disease-associated isoform (PrPD), and assembled onto the growing amyloid fibril. This fibular assembly is infectious, with ability to initiate disease processes similar to other pathogenic agents. Evidence indicates that scrapie, CWD, and TME disease processes follow this rule.
Collapse
|
2
|
Imamura M, Miyazawa K, Iwamaru Y, Matsuura Y, Yokoyama T, Okada H. Identification of the first case of atypical scrapie in Japan. J Vet Med Sci 2016; 78:1915-1919. [PMID: 27616556 PMCID: PMC5240776 DOI: 10.1292/jvms.16-0379] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A Corriedale ewe was confirmed as the first atypical scrapie case during an active surveillance program for transmissible spongiform encephalopathies in small ruminants in Japan. The animal was homozygous for the AF141RQ haplotype of PRNP. The animal showed clinical neurological signs possibly due to listeriosis before culling. Western blot analysis showed an unusual multiple banded pattern with a low-molecular fragment at ~7 kDa. Histopathology revealed suppurative meningoencephalitis caused by listeriosis in the brainstem. Fine granular to globular immunostaining of disease-associated prion proteins was mainly detected in the neuropil of the spinal tract of the trigeminal nerve and in the white matter of the spinocerebellar tract. Based on these results, this case was conclusively diagnosed as atypical scrapie with encephalitic listeriosis.
Collapse
Affiliation(s)
- Morikazu Imamura
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki 305-0856, Japan
| | | | | | | | | | | |
Collapse
|
3
|
Okada H, Miyazawa K, Imamura M, Iwamaru Y, Masujin K, Matsuura Y, Yokoyama T. Transmission of atypical scrapie to homozygous ARQ sheep. J Vet Med Sci 2016; 78:1619-1624. [PMID: 27320968 PMCID: PMC5095634 DOI: 10.1292/jvms.16-0259] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Two Cheviot ewes homozygous for the A136L141R154Q171 (AL141RQ) prion protein (PrP) genotype were exposed intracerebrally to brain pools prepared using four field cases of atypical scrapie from the United Kingdom. Animals were clinically normal until the end of the experiment, when they were culled 7 years post-inoculation. Limited accumulation of disease-associated PrP (PrPSc) was observed in the cerebellar molecular layer by immunohistochemistry, but not by western blot or enzyme-linked immunosorbent assay. In addition, PrPSc was partially localized in astrocytes and microglia, suggesting that these cells have a role in PrPSc processing, degradation or both. Our results indicate that atypical scrapie is transmissible to AL141RQ sheep, but these animals act as clinically silent carriers with long incubation times.
Collapse
Affiliation(s)
- Hiroyuki Okada
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki 305-0856, Japan
| | | | | | | | | | | | | |
Collapse
|
4
|
Chong A, Kennedy I, Goldmann W, Green A, González L, Jeffrey M, Hunter N. Archival search for historical atypical scrapie in sheep reveals evidence for mixed infections. J Gen Virol 2015; 96:3165-3178. [PMID: 26281831 DOI: 10.1099/jgv.0.000234] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Natural scrapie in sheep occurs in classical and atypical forms, which may be distinguished on the basis of the associated neuropathology and properties of the disease-associated prion protein on Western blots. First detected in 1998, atypical scrapie is known to have occurred in UK sheep since the 1980s. However, its aetiology remains unclear and it is often considered as a sporadic, non-contagious disease unlike classical scrapie which is naturally transmissible. Although atypical scrapie tends to occur in sheep of prion protein (PRNP) genotypes that are different from those found predominantly in classical scrapie, there is some overlap so that there are genotypes in which both scrapie forms can occur. In this search for early atypical scrapie cases, we made use of an archive of fixed and frozen sheep samples, from both scrapie-affected and healthy animals (∼1850 individuals), dating back to the 1960s. Using a selection process based primarily on PRNP genotyping, but also on contemporaneous records of unusual clinical signs or pathology, candidate sheep samples were screened by Western blot, immunohistochemistry and strain-typing methods using tg338 mice. We identified, from early time points in the archive, three atypical scrapie cases, including one sheep which died in 1972 and two which showed evidence of mixed infection with classical scrapie. Cases with both forms of scrapie in the same animal as recognizable entities suggest that mixed infections have been around for a long time and may potentially contribute to the variety of scrapie strains.
Collapse
Affiliation(s)
- Angela Chong
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Iain Kennedy
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Wilfred Goldmann
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Andrew Green
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Lorenzo González
- Animal and Plant Health Agency (APHA - Lasswade), Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Martin Jeffrey
- Animal and Plant Health Agency (APHA - Lasswade), Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Nora Hunter
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| |
Collapse
|
5
|
Piestrzyńska-Kajtoch A, Gurgul A, Polak MP, Smołucha G, Zmudziński JF, Rejduch B. Characterization of PRNP and SPRN coding regions from atypical scrapie cases diagnosed in Poland. Mol Biol Rep 2011; 39:2575-83. [PMID: 21674189 DOI: 10.1007/s11033-011-1010-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Accepted: 06/02/2011] [Indexed: 10/18/2022]
Abstract
Scrapie, a fatal transmissible spongiform encephalopathy (TSE) occurs in two phenotypes: classical and atypical. Many authors point out that the polymorphism of three codons (136, 154, 171) of the PRNP (PrP gene) is associated with a sheep susceptibility to classical scrapie. Until now, only one PRNP gene variant coding phenylalanine at codon 141 has been found to be associated with atypical scrapie. Another recently identified and interesting candidate gene for scrapie susceptibility in sheep is an SPRN gene coding for Shadoo protein (Sho). Sho is a highly interspecies conserved protein and an insertion/deletion (indel) found in a sheep Sho gene was associated with classical scrapie occurrence. Here we determined the polymorphism of PRNP and SPRN genes in nine atypical scrapie cases (six in native born sheep and three in imported sheep) and compared these results with a control group of healthy animals comprising six corresponding Polish sheep breeds. In atypical scrapie cases five PRNP diplotypes were identified: A(136)R(154)Q(171)/ARQ, AHQ/ARQ, ARR/ARQ, ARR/AHQ and AHQ/AHQ. The ARR/AHQ diplotype was found only in imported sheep. A previously unobserved SNP in PRNP (E224K) was also found in both atypical scrapie and in a few control animals. In the ORF of the SPRN gene, six SNPs and one indel were identified. None of these variations was exclusive for scrapie animals and they were probably, naturally occurring polymorphisms. Special attention was given to the 6-bp indel SPRN polymorphism which was previously associated with classical scrapie occurrence.
Collapse
Affiliation(s)
- Agata Piestrzyńska-Kajtoch
- Department of Animal Immuno- and Cytogenetics, National Research Institute of Animal Production, Krakowska 1, 32-083 Balice n Krakow, Poland
| | | | | | | | | | | |
Collapse
|
6
|
Distinct proteinase K-resistant prion protein fragment in goats with no signs of disease in a classical scrapie outbreak. J Clin Microbiol 2011; 49:2109-15. [PMID: 21450953 DOI: 10.1128/jcm.02033-10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Considerable efforts have been directed toward the identification of small-ruminant prion diseases, i.e., classical and atypical scrapie as well as bovine spongiform encephalopathy (BSE). Here we report the in-depth molecular analysis of the proteinase K-resistant prion protein core fragment (PrP(res)) in a highly scrapie-affected goat flock in Greece. The PrP(res) profile by Western immunoblotting in most animals was that of classical scrapie in sheep. However, in a series of clinically healthy goats we identified a unique C- and N-terminally truncated PrP(res) fragment, which is akin but not identical to that observed for atypical scrapie. These findings reveal novel aspects of the nature and diversity of the molecular PrP(res) phenotypes in goats and suggest that these animals display a previously unrecognized prion protein disorder.
Collapse
|
7
|
Abstract
Although prion diseases, such as Creutzfeldt-Jakob disease (CJD) in humans and scrapie in sheep, have long been recognized, our understanding of their epidemiology and pathogenesis is still in its early stages. Progress is hampered by the lengthy incubation periods and the lack of effective ways of monitoring and characterizing these agents. Protease-resistant conformers of the prion protein (PrP), known as the "scrapie form" (PrP(Sc)), are used as disease markers, and for taxonomic purposes, in correlation with clinical, pathological, and genetic data. In humans, prion diseases can arise sporadically (sCJD) or genetically (gCJD and others), caused by mutations in the PrP-gene (PRNP), or as a foodborne infection, with the agent of bovine spongiform encephalopathy (BSE) causing variant CJD (vCJD). Person-to-person spread of human prion disease has only been known to occur following cannibalism (kuru disease in Papua New Guinea) or through medical or surgical treatment (iatrogenic CJD, iCJD). In contrast, scrapie in small ruminants and chronic wasting disease (CWD) in cervids behave as infectious diseases within these species. Recently, however, so-called atypical forms of prion diseases have been discovered in sheep (atypical/Nor98 scrapie) and in cattle, BSE-H and BSE-L. These maladies resemble sporadic or genetic human prion diseases and might be their animal equivalents. This hypothesis also raises the significant public health question of possible epidemiological links between these diseases and their counterparts in humans.
Collapse
|
8
|
Jacobs JG, Sauer M, van Keulen LJM, Tang Y, Bossers A, Langeveld JPM. Differentiation of ruminant transmissible spongiform encephalopathy isolate types, including bovine spongiform encephalopathy and CH1641 scrapie. J Gen Virol 2010; 92:222-32. [PMID: 20943889 DOI: 10.1099/vir.0.026153-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
With increased awareness of the diversity of transmissible spongiform encephalopathy (TSE) strains in the ruminant population, comes an appreciation of the need for improved methods of differential diagnosis. Exposure to bovine spongiform encephalopathy (BSE) has been associated with the human TSE, variant Creutzfeldt-Jakob disease, emphasizing the necessity in distinguishing low-risk TSE types from BSE. TSE type discrimination in ruminants such as cattle, sheep, goats and deer, requires the application of several prion protein (PrP)-specific antibodies in parallel immunochemical tests on brain homogenates or tissue sections from infected animals. This study uses in a single incubation step, three PrP-specific antibodies and fluorescent Alexa dye-labelled anti-mouse Fabs on a Western blot. The usual amount of brain tissue needed is 0.5 mg. This multiplex application of antibodies directed towards three different PrP epitopes enabled differential diagnosis of all established main features of classical scrapie, BSE and Nor98-like scrapie in sheep and goats, as well as the currently known BSE types C, H and L in cattle. Moreover, due to an antibody-dependent dual PrP-banding pattern, for the first time CH1641 scrapie of sheep can be reliably discriminated from the other TSE isolate types in sheep.
Collapse
Affiliation(s)
- J G Jacobs
- Department of Infection Biology, Central Veterinary Institute of Wageningen UR, PO Box 65, 8200 AB Lelystad, The Netherlands
| | | | | | | | | | | |
Collapse
|
9
|
Stack M. Atypical scrapie: Impact on eradication policies. Vet J 2010; 186:6-7. [DOI: 10.1016/j.tvjl.2009.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 10/07/2009] [Indexed: 11/26/2022]
|
10
|
Rodríguez-Martínez AB, Garrido JM, Maza S, Benedicto L, Geijo M, Gómez N, Minguijón E, Benestad SL, Juste RA. Atypical/Nor98 scrapie in the Basque Country: a case report of eight outbreaks. BMC Vet Res 2010; 6:17. [PMID: 20346155 PMCID: PMC2859363 DOI: 10.1186/1746-6148-6-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 03/26/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since 2002, an active surveillance program for transmissible spongiform encephalopathy in small ruminants in European Union countries allowed identification of a considerable number of atypical cases with similarities to the previously identified atypical scrapie cases termed Nor98. CASE PRESENTATION Here we report molecular and neuropathological features of eight atypical/Nor98 scrapie cases detected between 2002 and 2009. Significant features of the affected sheep included: their relatively high ages (mean age 7.9 years, range between 4.3 and 12.8), their breed (all Latxa) and their PRNP genotypes (AFRQ/ALRQ, ALRR/ALRQ, AFRQ/AFRQ, AFRQ/AHQ, ALRQ/ALRH, ALRQ/ALRQ). All the sheep were confirmed as atypical scrapie by immunohistochemistry and immunoblotting. Two cases presented more PrP immunolabelling in cerebral cortex than in cerebellum. CONCLUSIONS This work indicates that atypical scrapie constitutes the most common small ruminant transmissible spongiform encephalopathy form in Latxa sheep in the Spanish Basque Country. Moreover, a new genotype (ALRQ/ALRH) was found associated to atypical scrapie.
Collapse
Affiliation(s)
| | - Joseba M Garrido
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| | - Sonia Maza
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| | - Leyre Benedicto
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| | - Mariví Geijo
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| | - Nieves Gómez
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| | | | - Sylvie L Benestad
- National Veterinary Institute, Department of Pathology, Postboks 750 Sentrum. 0106 Oslo. Norway
| | - Ramón A Juste
- Department of Animal Health. Neiker-Tecnalia, 48160 Derio. Bizkaia. Spain
| |
Collapse
|