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Corbière F, Perrin-Chauvineau C, Lacroux C, Costes P, Thomas M, Brémaud I, Martin S, Lugan S, Chartier C, Schelcher F, Barillet F, Andreoletti O. PrP-associated resistance to scrapie in five highly infected goat herds. J Gen Virol 2012; 94:241-245. [PMID: 23100359 DOI: 10.1099/vir.0.047225-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The PrP gene polymorphisms at codons 142 (I/M), 154 (R/H), 211 (R/Q), 222 (Q/K) and 240 (S/P) and their association with susceptibility to classical scrapie infection were investigated in five French goat herds displaying a high disease prevalence (>10%). On the basis of PrP(Sc) detection in the central nervous system and in various lymphoid tissues, 301 of 1343 goats were found to be scrapie infected. The statistical analyses indicated that while P(240) mutation had no direct impact on scrapie infection risk, the H(154), Q(211) and K(222) mutations were associated with high resistance to scrapie. The M(142) mutated allele was associated with a limited protection level against the disease. These results further reinforce the view that, like in sheep, the control and eradication of classical scrapie through the selection of certain PrP alleles could be envisaged in commercial goat population.
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Affiliation(s)
- Fabien Corbière
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
| | | | - Caroline Lacroux
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
| | - Pierrette Costes
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
| | - Myriam Thomas
- ANSES, Laboratoire d'Etudes et de Recherches Caprines, BP 3081, 79012 Niort Cedex, France
| | - Isabelle Brémaud
- ANSES, Laboratoire d'Etudes et de Recherches Caprines, BP 3081, 79012 Niort Cedex, France
| | - Samuel Martin
- ANSES, Laboratoire d'Etudes et de Recherches Caprines, BP 3081, 79012 Niort Cedex, France
| | - Séverine Lugan
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
| | - Christophe Chartier
- ANSES, Laboratoire d'Etudes et de Recherches Caprines, BP 3081, 79012 Niort Cedex, France
| | - François Schelcher
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
| | - Francis Barillet
- INRA, UR 631, Station d'Amélioration Génétique des Animaux, BP 52627, 31326 Castanet-Tolosan Cedex, France
| | - Olivier Andreoletti
- INRA, UMR 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse Cedex, France
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52
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White SN, Reynolds JO, Waldron DF, Schneider DA, O'Rourke KI. Extended scrapie incubation time in goats singly heterozygous for PRNP S146 or K222. Gene 2012; 501:49-51. [PMID: 22516690 DOI: 10.1016/j.gene.2012.03.068] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 11/28/2022]
Abstract
Scrapie is the transmissible spongiform encephalopathy (TSE) of sheep and goats, and scrapie eradication in sheep is based in part on strong genetic resistance to classical scrapie. Goats may serve as a scrapie reservoir, and to date there has been no experimental inoculation confirming strong genetic resistance in goats. Two prion protein variants (amino acid substitutions S146 and K222) in goats have been significantly underrepresented in scrapie cases though present in scrapie-exposed flocks, and have demonstrated low cell-free protein conversion efficiency to the disease form (PrP(D)). To test degree of genetic resistance conferred in live animals with consistent exposure, we performed the first oral scrapie challenge of goats singly heterozygous for either PRNP S146 or K222. All N146-Q222 homozygotes became clinically scrapie positive by an average of 24months, but all S146 and K222 heterozygotes remain scrapie negative by both rectal biopsy and clinical signs at significantly longer incubation times (P<0.0001 for both comparisons). Recent reports indicate small numbers of S146 and K222 heterozygous goats have become naturally infected with scrapie, suggesting these alleles do not confer complete resistance in the heterozygous state but rather extend incubation. The oral challenge results presented here confirm extended incubation observed in a recent intracerebral challenge of K222 heterozygotes, and to our knowledge provide the first demonstration of extended incubation in S146 heterozygotes. These results suggest longer relevant trace-back histories in scrapie-eradication programs for animals bearing these alleles and strengthen the case for additional challenge experiments in both homozygotes to assess potential scrapie resistance.
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Affiliation(s)
- Stephen N White
- Animal Disease Research Unit, Agricultural Research Service, U.S. Department of Agriculture, PO Box 646630, Pullman, WA 99164, USA.
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53
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Resistance to classical scrapie in experimentally challenged goats carrying mutation K222 of the prion protein gene. Vet Res 2012; 43:8. [PMID: 22296670 PMCID: PMC3296670 DOI: 10.1186/1297-9716-43-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 02/01/2012] [Indexed: 11/23/2022] Open
Abstract
Susceptibility of sheep to scrapie, a transmissible spongiform encephalopathy of small ruminants, is strongly influenced by polymorphisms of the prion protein gene (PRNP). Breeding programs have been implemented to increase scrapie resistance in sheep populations; though desirable, a similar approach has not yet been applied in goats. European studies have now suggested that several polymorphisms can modulate scrapie susceptibility in goats: in particular, PRNP variant K222 has been associated with resistance in case-control studies in Italy, France and Greece. In this study we investigated the resistance conferred by this variant using a natural Italian goat scrapie isolate to intracerebrally challenge five goats carrying genotype Q/Q 222 (wild type) and five goats carrying genotype Q/K 222. By the end of the study, all five Q/Q 222 goats had died of scrapie after a mean incubation period of 19 months; one of the five Q/K 222 goats died after 24 months, while the other four were alive and apparently healthy up to the end of the study at 4.5 years post-challenge. All five of these animals were found to be scrapie negative. Statistical analysis showed that the probability of survival of the Q/K 222 goats versus the Q/Q 222 goats was significantly higher (p = 0.002). Our study shows that PRNP gene mutation K222 is strongly associated with resistance to classical scrapie also in experimental conditions, making it a potentially positive target for selection in the frame of breeding programs for resistance to classical scrapie in goats.
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54
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Abstract
Prion diseases occur in many animal species, most notably in ruminants. While scrapie in sheep has been recognised for three centuries and goat scrapie has been recognised for decades, BSE in cattle is a relatively novel disease which was first diagnosed in the UK in the mid 1980s. BSE was most likely caused through dietary exposure to animal feed contaminated with prions and disease was subsequently transmitted to people. The BSE epidemic is almost at an end, but the recent identification of so called atypical forms of BSE and scrapie pose many questions about the possible spectrum of prion diseases in animals and their transmissibility to other species, including humans.The pathogenesis of animal prion diseases has been studied both in natural infections and in experimental animal models. Detection of infectivity is greatly helped by suitable rodent models, in particular transgenic mice. Clinically infected animals show characteristic neuropathology in the brain and spinal cord which is accompanied by the accumulation of a conformationally altered, protease-resistant host protein. The post-mortem diagnosis is based on the detection of this protein, PrP(Sc), but despite recent impressive developments a routine ante-mortem diagnostic test has proved elusive.There is no treatment for prion diseases in animals, but disease outbreaks are controlled through a mixture of movement restrictions on holdings, culling of affected animals and herds and, for classical scrapie in sheep, selective breeding for genetic resistance. Prions are very stable and can remain in the environment for prolonged periods. This poses serious practical questions with regard to the decontamination of infected premises. The control of BSE specifically through restrictions in animal feeding practises has been successful, but the changing spectrum of these diseases plus the economic pressures to relax feed bans and reduce levels of surveillance will require constant vigilance to safeguard animal and public health.
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55
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Goldmann W, Ryan K, Stewart P, Parnham D, Xicohtencatl R, Fernandez N, Saunders G, Windl O, González L, Bossers A, Foster J. Caprine prion gene polymorphisms are associated with decreased incidence of classical scrapie in goat herds in the United Kingdom. Vet Res 2011; 42:110. [PMID: 22040234 PMCID: PMC3224758 DOI: 10.1186/1297-9716-42-110] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/31/2011] [Indexed: 12/31/2022] Open
Abstract
The application of genetic breeding programmes to eradicate transmissible spongiform encephalopathies in goats is an important aim for reasons of animal welfare as well as human food safety and food security. Based on the positive impact of Prnp genetics on sheep scrapie in Europe in the past decade, we have established caprine Prnp gene variation in more than 1100 goats from the United Kingdom and studied the association of Prnp alleles with disease phenotypes in 150 scrapie-positive goats. This investigation confirms the association of the Met142 encoding Prnp allele with increased resistance to preclinical and clinical scrapie. It reveals a novel association of the Ser127 encoding allele with a reduced probability to develop clinical signs of scrapie in goats that are already positive for the accumulation of disease-specific prion protein in brain or periphery. A United Kingdom survey of Prnp genotypes in eight common breeds revealed eleven alleles in over thirty genotypes. The Met142 encoding allele had a high overall mean allele frequency of 22.6%, whereas the Ser127 encoding allele frequency was considerably lower with 6.4%. In contrast, a well known resistance associated allele encoding Lys222 was found to be rare (0.9%) in this survey. The analysis of Prnp genotypes in Mexican Criollas goats revealed nine alleles, including a novel Phe to Leu substitution in codon 201, confirming that high genetic variability of Prnp can be found in scrapie-free populations. Our study implies that it should be feasible to lower scrapie prevalence in goat herds in the United Kingdom by genetic selection.
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Affiliation(s)
- Wilfred Goldmann
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Kelly Ryan
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Paula Stewart
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - David Parnham
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Rosa Xicohtencatl
- Facultad de Medicina Veterinaria y Zootecnia, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Nora Fernandez
- Facultad de Medicina Veterinaria y Zootecnia, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Ginny Saunders
- Animal Health and Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey, UK
| | - Otto Windl
- Animal Health and Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey, UK
| | - Lorenzo González
- Animal Health and Veterinary Laboratories Agency, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK
| | - Alex Bossers
- Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands
| | - James Foster
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
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56
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Fragkiadaki EG, Vaccari G, Ekateriniadou LV, Agrimi U, Giadinis ND, Chiappini B, Esposito E, Conte M, Nonno R. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks. Vet Res 2011; 42:104. [PMID: 21961834 PMCID: PMC3190342 DOI: 10.1186/1297-9716-42-104] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 09/30/2011] [Indexed: 11/16/2022] Open
Abstract
One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.
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Affiliation(s)
- Eirini G Fragkiadaki
- National Agricultural Research Foundation, Veterinary Research Institute, Thessaloniki, Greece.
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57
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Eiden M, Soto EO, Mettenleiter TC, Groschup MH. Effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion. Vet Res 2011; 42:30. [PMID: 21324112 PMCID: PMC3050705 DOI: 10.1186/1297-9716-42-30] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 02/15/2011] [Indexed: 11/10/2022] Open
Abstract
In sheep polymorphisms of the prion gene (PRNP) at the codons 136, 154 and 171 strongly influence the susceptibility to scrapie and bovine spongiform encephalopathy (BSE) infections. In goats a number of other gene polymorphisms were found which are suspected to trigger similar effects. However, no strong correlation between polymorphisms and TSE susceptibility in goats has yet been obtained from epidemiological studies and only a low number of experimental challenge data are available at present. We have therefore studied the potential impact of these polymorphisms in vitro by cell-free conversion assays using mouse scrapie strain Me7. Mouse scrapie brain derived PrPSc served as seeds and eleven recombinant single mutation variants of sheep and goat PrPC as conversion targets. With this approach it was possible to assign reduced conversion efficiencies to specific polymorphisms, which are associated to low frequency in scrapie-affected goats or found only in healthy animals. Moreover, we could demonstrate a dominant-negative inhibition of prion polymorphisms associated with high susceptibility by alleles linked to low susceptibility in vitro.
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Affiliation(s)
- Martin Eiden
- Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, D-17493 Greifswald-Insel Riems, Germany.
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58
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O'Rourke KI, Zhuang D, Truscott TC, Yan H, Schneider DA. Sparse PrP(Sc) accumulation in the placentas of goats with naturally acquired scrapie. BMC Vet Res 2011; 7:7. [PMID: 21284878 PMCID: PMC3041672 DOI: 10.1186/1746-6148-7-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 02/01/2011] [Indexed: 12/31/2022] Open
Abstract
Background Domestic goats (Capra hircus) are a natural and experimental host of scrapie and bovine spongiform encephalopathy, the transmissible spongiform encephalopathies (TSE) of sheep and cattle. Goats are also susceptible to experimental infection with the agents of TSEs of deer and elk (chronic wasting disease) and humans (Creutzfeldt Jakob disease). Distribution of PrPSc, the abnormal prion protein, is similar in the tissues of scrapie-infected sheep and goats but no data are available on the potential shedding of the agent through the placenta, the presumed route of transmission of ovine scrapie. We describe the sparse accumulation of PrPSc in the placentas of goats with naturally acquired classical scrapie in comparison to field cases of classical ovine scrapie. Results PrPSc was detected in the shed placentas from a sample of U.S. goats with naturally occurring scrapie, diagnosed by antemortem lymphoid tissue biopsy or identified as high risk progeny of infected dams. PrPSc accumulation patterns in the intact placentome and western blot banding was similar in the caprine and ovine samples. However, levels of PrPSc estimated from ELISA and immunohistochemistry assays were generally lower in goats than in sheep, although wide variation was noted in both species. Conclusions PrPSc accumulates in the shed placentas of goats with naturally acquired scrapie. Although these levels were low in most caprine samples, the caprine placenta may contribute to prion contamination of kidding facilities and transmission to co-housed sheep or goats.
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Affiliation(s)
- Katherine I O'Rourke
- Animal Disease Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164, USA.
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