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Sample records for scrapie

  1. Sheep Feed and Scrapie, France

    Science.gov (United States)

    Philippe, Sandrine; Ducrot, Christian; Roy, Pascal; Remontet, Laurent; Jarrige, Nathalie

    2005-01-01

    Scrapie is a small ruminant, transmissible spongiform encephalopathy (TSE). Although in the past scrapie has not been considered a zoonosis, the emergence of bovine spongiform encephalopathy, transmissible to humans and experimentally to sheep, indicates that risk exists for small ruminant TSEs in humans. To identify the risk factors for introducing scrapie into sheep flocks, a case-control study was conducted in France from 1999 to 2000. Ninety-four case and 350 control flocks were matched by location and main breed. Three main hypotheses were tested: direct contact between flocks, indirect environmental contact, and foodborne risk. Statistical analysis was performed by using adjusted generalized linear models with the complementary log-log link function, considering flock size as an offset. A notable effect of using proprietary concentrates and milk replacers was observed. The risk was heterogeneous among feed factories. Contacts between flocks were not shown to be a risk factor. PMID:16102318

  2. Prion protein and scrapie susceptibility

    NARCIS (Netherlands)

    Smits, M.A.; Bossers, A.; Schreuder, B.E.C.

    1997-01-01

    This article presents briefly current views on the role of prion protein (PrP) in Transmissible Spongiform Encephalopathies or prion diseases and the effect of PrP polymoryhisms on the susceptibility to these diseases, with special emphasis on sheep scrapie. The PrP genotype of sheep apears to be a

  3. Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

    Directory of Open Access Journals (Sweden)

    Timm eKonold

    2015-09-01

    Full Text Available Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial Protein Misfolding Cyclic Amplification (sPMCA have suggested that objects on a scrapie-affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing and other objects that sheep may rub against used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation sheep became infected when exposed to either a water trough (four out of five or to objects used for rubbing (four out of seven. This field furniture had been used by the scrapie-infected flock eight weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23 through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12 on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie-free.The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.

  4. Selective breeding for scrapie resistance in sheep

    Directory of Open Access Journals (Sweden)

    Cristina Santos Sotomaior

    2012-11-01

    Full Text Available It is well known that the susceptibility of sheep to scrapie is determined by the host’s prion protein gene (PRNP. PRNP polymorphisms at codons 136 (alanine, A/valine, V, 154 (histidine, H/arginine, R and 171 (glutamine, Q/histidine, H/arginine, R are the main determinants of sheep susceptibility/resistance to classical scrapie. There are four major variants of the wild-type ARQ allele: VRQ, AHQ, ARH and ARR. Breeding programs have been developed in the European Union and the USA to increase the frequency of the resistant ARR allele while decreasing the frequency of the susceptible VRQ allele in sheep populations. In Brazil, little PRNP genotyping data are available for sheep, and thus far, no controlled breeding scheme for scrapie has been implemented. This review will focus on important epidemiological aspects of scrapie and the use of genetic resistance as a tool in breeding programs to control the disease.

  5. Genetic evidence for susceptibility and resistance against scrapie in ...

    Indian Academy of Sciences (India)

    2015-03-04

    Mar 4, 2015 ... Scrapie is a fatal, neurodegenerative disease of sheep and goats (Prusiner ... and/or resistance of Indian sheep to scrapie via some other .... (model 583). ..... tory manual, 3rd edition, Cold spring Harbour Laboratory Press,.

  6. Selectie tegen gevoeligheid voor scrapie met behoud van genetische variatie = Selection against scrapie susceptibility while maintaining within breed genetic variation

    NARCIS (Netherlands)

    Windig, J.J.; Hoving, A.H.

    2009-01-01

    National legislation to breed for scrapie resistence was changed in 2007. The obligatory use of ARR/ARR rams was suspended in that year. Breeding for scrapie resistance is, however, still stimulated and not suspended. In this report a general advice on how to continue breeding for scrapie resistance

  7. Experimental transmission of atypical scrapie to sheep

    Directory of Open Access Journals (Sweden)

    Spiropoulos John

    2007-08-01

    Full Text Available Abstract Background Active surveillance for transmissible spongiform encephalopathies in small ruminants has been an EU regulatory requirement since 2002. A number of European countries have subsequently reported cases of atypical scrapie, similar to previously published cases from Norway, which have pathological and molecular features distinct from classical scrapie. Most cases have occurred singly in flocks, associated with genotypes considered to be more resistant to classical disease. Experimental transmissibility of such isolates has been reported in certain ovinised transgenic mice, but has not previously been reported in the natural host. Information on the transmissibility of this agent is vital to ensuring that disease control measures are effective and proportionate. Results This report presents the successful experimental transmission, in 378 days, of atypical scrapie to a recipient sheep of homologous genotype with preservation of the pathological and molecular characteristics of the donor. This isolate also transmitted to ovinised transgenic mice (Tg338 with a murine phenotype indistinguishable from that of Nor 98. Conclusion This result strengthens the opinion that these cases result from a distinct strain of scrapie agent, which is potentially transmissible in the natural host under field conditions.

  8. Epidemiological analysis of data for scrapie in Great Britain

    NARCIS (Netherlands)

    Hagenaars, T.H.J.; Donnelly, C.; Ferguson, N.M.

    2006-01-01

    In recent years, the control or eradication of scrapie and any other transmissible spongiform encephalopathies (TSEs) possibly circulating in the sheep population has become a priority in Britain and elsewhere in Europe. A better understanding of the epidemiology of scrapie would greatly aid the

  9. 9 CFR 54.10 - Tests for scrapie.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Tests for scrapie. 54.10 Section 54.10... tests may be approved for the identification of suspect animals, for the identification of scrapie-positive animals, or for other purposes such as flock certification. For a test to be approved for the...

  10. Extended scrapie incubation time in goats singly heterozygous for PRNP S146 or K222

    Science.gov (United States)

    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 genet...

  11. Design and Implementation of Distributed Crawler System Based on Scrapy

    Science.gov (United States)

    Fan, Yuhao

    2018-01-01

    At present, some large-scale search engines at home and abroad only provide users with non-custom search services, and a single-machine web crawler cannot sovle the difficult task. In this paper, Through the study and research of the original Scrapy framework, the original Scrapy framework is improved by combining Scrapy and Redis, a distributed crawler system based on Web information Scrapy framework is designed and implemented, and Bloom Filter algorithm is applied to dupefilter modul to reduce memory consumption. The movie information captured from douban is stored in MongoDB, so that the data can be processed and analyzed. The results show that distributed crawler system based on Scrapy framework is more efficient and stable than the single-machine web crawler system.

  12. Genotyping and surveillance for scrapie in Finnish sheep

    Directory of Open Access Journals (Sweden)

    Hautaniemi Maria

    2012-07-01

    Full Text Available Abstract Background The progression of scrapie is known to be influenced by the amino acid polymorphisms of the host prion protein (PrP gene. There is no breeding programme for TSE resistance in sheep in Finland, but a scrapie control programme has been in place since 1995. In this study we have analysed PrP genotypes of total of 928 purebred and crossbred sheep together with the data of scrapie survey carried out in Finland during 2002–2008 in order to gain knowledge of the genotype distribution and scrapie prevalence in Finnish sheep. Results The ARQ/ARQ genotype was the most common genotype in all breeds studied. ARR allele frequency was less than 12% in purebred Finnish sheep and in most genotypes heterozygous for ARR, the second allele was ARQ. The VRQ allele was not detected in the Grey race sheep of Kainuu or in the Aland sheep, and it was present in less than 6% of the Finnish Landrace sheep. Leucine was the most prominent amino acid found in codon 141. In addition, one novel prion dimorphisms of Q220L was detected. During the scrapie survey of over 15 000 sheep in 2002–2008, no classical scrapie cases and only five atypical scrapie cases were detected. Conclusions The results indicate that the Finnish sheep populations have genetically little resistance to classical scrapie, but no classical scrapie was detected during an extensive survey in 2002–2008. However, five atypical scrapie cases emerged; thus, the disease is present in the Finnish sheep population at a low level.

  13. Evidence of scrapie transmission to sheep via goat milk.

    Science.gov (United States)

    Konold, Timm; Thorne, Leigh; Simmons, Hugh A; Hawkins, Steve A C; Simmons, Marion M; González, Lorenzo

    2016-09-17

    Previous studies confirmed that classical scrapie can be transmitted via milk in sheep. The current study aimed to investigate whether scrapie can also be transmitted via goat milk using in vivo (new-born lambs fed milk from scrapie-affected goats due to the unavailability of goat kids from guaranteed scrapie-free herds) and in vitro methods (serial protein misfolding cyclic amplification [sPMCA] on milk samples). In an initial pilot study, new-born lambs of two different prion protein gene (PRNP) genotypes (six VRQ/VRQ and five ARQ/ARQ) were orally challenged with 5 g brain homogenate from two scrapie-affected goats to determine susceptibility of sheep to goat scrapie. All sheep challenged with goat scrapie brain became infected based on the immunohistochemical detection of disease-associated PrP (PrP(sc)) in lymphoid tissue, with an ARQ/ARQ sheep being the first to succumb. Subsequent feeding of milk to eight pairs of new-born ARQ/ARQ lambs, with each pair receiving milk from a different scrapie-affected goat, resulted in scrapie in the six pairs that received the largest volume of milk (38-87 litres per lamb), whereas two pairs fed 8-9 litres per lamb, and an environmental control group raised on sheep milk from healthy ewes, did not show evidence of infection when culled at up to 1882 days of age. Infection in those 12 milk recipients occurred regardless of the clinical status, PrP(sc) distribution, caprine arthritis-encephalitis virus infection status and PRNP polymorphisms at codon 142 (II or IM) of the donor goats, but survival time was influenced by PRNP polymorphisms at codon 141. Serial PMCA applied to a total of 32 milk samples (four each from the eight donor goats collected throughout lactation) detected PrP(sc) in one sample each from two goats. The scrapie agent was present in the milk from infected goats and was able to transmit to susceptible species even at early preclinical stage of infection, when PrP(sc) was undetectable in the brain of the

  14. Using mass spectrometry to determine the relative susceptibility of PrP polymorphisms to atypical scrapie

    Science.gov (United States)

    A novel form of scrapie was described in 1998 and referred to as Nor98 for the country of origin and date of its discovery. Since then it has been found in numerous countries, including New Zealand and Australia, and has been renamed atypical scrapie. Unlike classical scrapie, the epidemiology of th...

  15. Immunohistochemical detection of prion protein in lymphoid tissues of sheep with natural scrapie

    NARCIS (Netherlands)

    Keulen, van L.J.M.; Schreuder, B.E.C.; Meloen, R.H.; Mooij-Harkes, G.; Vromans, M.E.W.; Langeveld, J.P.M.

    1996-01-01

    The scrapie-associated form of the prion protein (PrP(Sc)) accumulates in the brain and lymphoid tissues of sheep with scrapie. In order to assess whether detecting PrP(Sc) in lymphoid tissue could he used as a diagnostic test for scrapie, we studied the localization and distribution of PrP(Sc) in

  16. Genetic Resistance to Scrapie Infection in Experimentally Challenged Goats

    Science.gov (United States)

    Lacroux, Caroline; Perrin-Chauvineau, Cécile; Corbière, Fabien; Aron, Naima; Aguilar-Calvo, Patricia; Torres, Juan Maria; Costes, Pierrette; Brémaud, Isabelle; Lugan, Séverine; Schelcher, François; Barillet, Francis

    2014-01-01

    In goats, several field studies have identified coding mutations of the gene encoding the prion protein (I/M142, N/D146, S/D146, R/Q211, and Q/K222) that are associated with a lower risk of developing classical scrapie. However, the data related to the levels of resistance to transmissible spongiform encephalopathies (TSEs) of these different PRNP gene mutations are still considered insufficient for developing large-scale genetic selection against scrapie in this species. In this study, we inoculated wild-type (WT) PRNP (I142R154R211Q222) goats and homozygous and/or heterozygous I/M142, R/H154, R/Q211, and Q/K222 goats with a goat natural scrapie isolate by either the oral or the intracerebral (i.c.) route. Our results indicate that the I/M142 PRNP polymorphism does not provide substantial resistance to scrapie infection following intracerebral or oral inoculation. They also demonstrate that H154, Q211, and K222 PRNP allele carriers are all resistant to scrapie infection following oral exposure. However, in comparison to WT animals, the H154 and Q211 allele carriers displayed only moderate increases in the incubation period following i.c. challenge. After i.c. challenge, heterozygous K222 and a small proportion of homozygous K222 goats also developed the disease, but with incubation periods that were 4 to 5 times longer than those in WT animals. These results support the contention that the K222 goat prion protein variant provides a strong but not absolutely protective effect against classical scrapie. PMID:24284317

  17. Clinical findings in two cases of atypical scrapie in sheep: a case report

    Directory of Open Access Journals (Sweden)

    Chaplin Melanie

    2007-02-01

    Full Text Available Abstract Background Atypical scrapie is a recently recognised form of transmissible spongiform encephalopathy of sheep that differs from classical scrapie in its neuropathological and biochemical features. Most cases are detected in apparently healthy sheep and information on the clinical presentation is limited. Case presentation This report describes the clinical findings in two sheep notified as scrapie suspects and confirmed as atypical scrapie cases by immunohistochemistry and Western immunoblotting. Although both sheep displayed signs suggestive of a cerebellar dysfunction there was considerable variation in the individual clinical signs, which were similar to classical scrapie. Conclusion Any sheep presenting with neurological gait deficits should be assessed more closely for other behavioural, neurological and physical signs associated with scrapie and their presence should lead to the suspicion of scrapie.

  18. Scrapie-specific pathology of sheep lymphoid tissues.

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    Gillian McGovern

    Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases often result in accumulation of disease-associated PrP (PrP(d in the lymphoreticular system (LRS, specifically in association with follicular dendritic cells (FDCs and tingible body macrophages (TBMs of secondary follicles. We studied the effects of sheep scrapie on lymphoid tissue in tonsils and lymph nodes by light and electron microscopy. FDCs of sheep were grouped according to morphology as immature, mature or regressing. Scrapie was associated with FDC dendrite hypertrophy and electron dense deposit or vesicles. PrP(d was located using immunogold labelling at the plasmalemma of FDC dendrites and, infrequently, mature B cells. Abnormal electron dense deposits surrounding FDC dendrites were identified as immunoglobulins suggesting that excess immune complexes are retained and are indicative of an FDC dysfunction. Within scrapie-affected lymph nodes, macrophages outside the follicle and a proportion of germinal centre TBMs accumulated PrP(d within endosomes and lysosomes. In addition, TBMs showed PrP(d in association with the cell membrane, non-coated pits and vesicles, and also with discrete, large and random endoplasmic reticulum networks, which co-localised with ubiquitin. These observations suggest that PrP(d is internalised via the caveolin-mediated pathway, and causes an abnormal disease-related alteration in endoplasmic reticulum structure. In contrast to current dogma, this study shows that sheep scrapie is associated with cytopathology of germinal centres, which we attribute to abnormal antigen complex trapping by FDCs and abnormal endocytic events in TBMs. The nature of the sub-cellular changes in FDCs and TBMs differs from those of scrapie infected neurones and glial cells suggesting that different PrP(d/cell membrane interactions occur in different cell types.

  19. Discrepant epidemiological patterns between classical and atypical scrapie in sheep flocks under French TSE control measures.

    Science.gov (United States)

    Fediaevsky, Alexandre; Gasqui, Patrick; Calavas, Didier; Ducrot, Christian

    2010-09-01

    The occurrence of secondary cases of atypical and classical scrapie was examined in 340 outbreaks of atypical and 296 of classical sheep scrapie detected in France during active surveillance programmes between 2002 and 2007. The prevalence of atypical scrapie in these flocks was 0.05% under selective culling and 0.07% under intensified monitoring i.e. not significantly different from that detected during active surveillance of the general population (P>0.5), whereas these figures were much higher for classical scrapie (3.67% and 0.25%, respectively, Pclassical scrapie but were not more efficient than active surveillance in detecting cases of atypical scrapie. Copyright 2009 Elsevier Ltd. All rights reserved.

  20. Spatial reversal learning in preclinical scrapie-inoculated mice.

    Science.gov (United States)

    Lysons, A M; Woollard, S J

    1996-04-10

    Acquisition and reversal of a two-choice spatial discrimination were tested in scrapie-inoculated mice. Both acquisition and reversal were normal in mice tested 138 and 103 days prior to the onset of clinical symptoms. At 65 days before onset of clinical symptoms, scrapie-inoculated mice required more trails to criterion in reversal learning, but this effect was not significant in a second experiment (68 days preclinical) and was transient: no effect was seen 33 days before symptoms. However, the course of reversal learning was abnormal in all three late preclinical groups (68, 65 and 33 days before symptoms). Reversal learning in these three groups was characterized by a rapid extinction of the original discrimination, followed by a period, absent in controls, during which performance showed no further improvement. This effect corresponds in time of onset to the appearance of characteristic neuropathological features.

  1. An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

    Directory of Open Access Journals (Sweden)

    Lisa Boden

    Full Text Available Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS. However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years. Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic. The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

  2. Prenatal transmission of scrapie in sheep and goats: A case study ...

    African Journals Online (AJOL)

    ... or unwashed in vivo derived embryos are hazards for the transmission of scrapie. Evidence from causal reasoning, including experience from other prion diseases, shows that mechanisms exist for prenatal transmission and transmission by semen and embryos in both sheep and goats. Keywords: Goat, Prenatal, Scrapie, ...

  3. Selection for scrapie resistance and simultaneous restriction of inbreeding in the rare sheep breed "Mergellander"

    NARCIS (Netherlands)

    Windig, J.J.; Meuleman, H.; Lansbergen, L.M.T.E.

    2007-01-01

    Scrapie is a fatal infectious neurodegenerative disease for which susceptibility is associated with polymorphisms in the ovine prion protein (PrP) gene. Scrapie-eradication programmes are based on eliminating the susceptible VRQ allele and/or breeding for the resistant ARR allele. In rare breeds or

  4. Identification of prion protein gene polymorphisms in goats from Italian scrapie outbreaks

    NARCIS (Netherlands)

    Acutis, P.L.; Bossers, A.; Priem, J.; Riina, M.V.; Peletto, S.; Mazza, M.; Casalone, C.; Forloni, G.; Ru, G.; Caramelli, M.

    2006-01-01

    Susceptibility to scrapie in sheep is influenced by polymorphisms of the prion protein (PrP) gene, whereas no strong association between genetics and scrapie has yet been determined in goats due to the limited number of studies on these animals. In this case¿control study on 177 goats from six

  5. Immunohistochemical distinction between preclinical bovine spongiform encephalopathy and scrapie infection in sheep

    NARCIS (Netherlands)

    Thuring, C.M.A.; Keulen, van L.J.M.; Langeveld, J.P.M.; Vromans, M.E.W.; Zijderveld, van F.G.; Sweeney, T.

    2005-01-01

    Sheep are susceptible experimentally to bovine spongiform encephalopathy (BSE), the clinical signs being indistinguishable from those of scrapie. Because of the possibility of natural ovine BSE infection, laboratory tests are needed to distinguish between scrapie and BSE infection. The objectives of

  6. Scrapie resistant goats: Keep your herd healthy and help your business with a new gene test

    Science.gov (United States)

    Classical scrapie is an infectious disease of goats and sheep that causes slowly progressive but ultimately fatal degeneration of the brain, with advanced cases often hindering their ability to move properly. Currently, a single diagnosis of classical scrapie results in permanent quarantine or eutha...

  7. Scrapie prion liposomes and rods exhibit target sizes of 55,000 Da

    International Nuclear Information System (INIS)

    Bellinger-Kawahara, C.G.; Kempner, E.; Groth, D.; Gabizon, R.; Prusiner, S.B.

    1988-01-01

    Scrapie is a degenerative neurologic disease in sheep and goats which can be experimentally transmitted to laboratory rodents. Considerable evidence suggests that the scrapie agent is composed largely, if not entirely, of an abnormal isoform of the prion protein (PrPSc). Inactivation of scrapie prions by ionizing radiation exhibited single-hit kinetics and gave a target size of 55,000 +/- 9000 mol wt. The inactivation profile was independent of the form of the prion. Scrapie agent infectivity in brain homogenates, microsomal fractions, detergent-extracted microsomes, purified amyloid rods, and liposomes exhibited the same inactivation profile. Our data are consistent with the hypothesis that the infectious particle causing scrapie contains approximately 2 PrPSc molecules

  8. The Shetland Islands scrapie monitoring and control programme: analysis of the clinical data collected from 772 scrapie suspects 1985-1997.

    Science.gov (United States)

    Cockcroft, P D; Clark, A M

    2006-02-01

    There were 574 scrapie positive suspects (histopathological scrapie lesions present) and 198 scrapie negative suspects (histopathological scrapie lesions absent). The greatest number of scrapie cases were recorded in sheep of 2, 3 and 4 years of age which represented 17%, 36% and 23% of the scrapie positive suspects, respectively. The sign sensitivities and specificities for the ten recorded signs were, respectively: pruritus (62%, 42%), ataxia (23%, 74%), hyperaesthesia (32%, 74%), wool loss (25%, 73%), fleece discolouration (29%, 85%), bruxism (23%, 69%), nibbling reflex (17%, 58%), head rubbing (47%, 78%), poll rubbing (25%, 83%). These single signs had poor discriminatory values with likelihood ratios close to one (range 0.89-1.21); combinations of the four signs, pruritus, wool loss, ataxia, hyperaesthesia and emaciation were more discriminatory (range 0.30-4.3). This study covered a time period when bovine spongiform encephalopathy (BSE) might have been introduced into the sheep population on the Shetland Islands via contaminated feed. No temporal changes could be detected in the age structure of the affected animals.

  9. Prions in milk from ewes incubating natural scrapie.

    Directory of Open Access Journals (Sweden)

    Caroline Lacroux

    2008-12-01

    Full Text Available Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrP(Sc accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 microg of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species.

  10. The scrapie disease process is unaffected by ionizing radiation

    International Nuclear Information System (INIS)

    Fraser, H.; Farquhar, C.F.; McConnell, I.; Davies, D.

    1989-01-01

    The incubation period of scrapie, its degenerative neuropathology and the replication of its causal unconventional virus are all tightly controlled parameters of the experimental disease in mice. Each parameter can vary depending on the strain and dose of virus, on the route of infection, and on the host genotype. Exposure to whole-body gamma-irradiation from Cesium 137 has no effect on the progress or development of the disease, based on the three independent indices of incubation period, neuropathology, or infectibility by high or low doses of virus. These results are based on an extensive series of experiments in many mouse strains and are consistent using different strains (ME7, 22A, 79A, 87V) and doses of virus, routes of infection, timing and dose of radiation (3-15 Gy) administered as single or fractionated exposures with or without bone-marrow (b.m.) replacement therapy. Levels of infection in the spleen are unaltered after lethal whole-body irradiation of the scrapie-infected host, despite several-fold reductions in tissue mass due to the loss of proliferating myeloid and lymphoid precursor cells and their progeny. Contrary to our earlier suggestion, scrapie infection with the 22A virus does not reduce the effectiveness of post-exposure bone-marrow replacements to recolonize an infected host after repeated ionizing radiation totalling 15Gy. This work narrows the search for the candidate cells and biosynthetic systems which replicate the virus in the lymphoreticular and central nervous systems. Many programmed cellular events are radiation sensitive but protein synthesis is extremely radioresistant

  11. The placenta shed from goats with classical scrapie is infectious to goat kids and lambs.

    Science.gov (United States)

    Schneider, David A; Madsen-Bouterse, Sally A; Zhuang, Dongyue; Truscott, Thomas C; Dassanayake, Rohana P; O'Rourke, Katherine I

    2015-08-01

    The placenta of domestic sheep plays a key role in horizontal transmission of classical scrapie. Domestic goats are frequently raised with sheep and are susceptible to classical scrapie, yet potential routes of transmission from goats to sheep are not fully defined. Sparse accumulation of disease-associated prion protein in cotyledons casts doubt about the role of the goat's placenta. Thus, relevant to mixed-herd management and scrapie-eradication efforts worldwide, we determined if the goat's placenta contains prions orally infectious to goat kids and lambs. A pooled cotyledon homogenate, prepared from the shed placenta of a goat with naturally acquired classical scrapie disease, was used to orally inoculate scrapie-naïve prion genotype-matched goat kids and scrapie-susceptible lambs raised separately in a scrapie-free environment. Transmission was detected in all four goats and in two of four sheep, which importantly identifies the goat's placenta as a risk for horizontal transmission to sheep and other goats.

  12. Epidemiological characteristics of classical scrapie outbreaks in 30 sheep flocks in the United Kingdom.

    Directory of Open Access Journals (Sweden)

    K Marie McIntyre

    Full Text Available Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics between flocks, including flock-level prion protein (PrP genotype profile. In total, the study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.We found that most scrapie cases were restricted to just two PrP genotypes (ARQ/VRQ and VRQ/VRQ, though two flocks had markedly different affected genotypes, despite having similar underlying genotype profiles to other flocks of the same breed; we identified differences amongst flocks in the age of cases of certain PrP genotypes; we found that the age-at-onset of clinical signs depended on peak incidence and flock type; we found evidence that purchasing infected animals is an important means of introducing scrapie to a flock; we found some evidence that flock-level PrP genotype profile and flock size account for variation in outbreak characteristics; identified seasonality in cases associated with lambing time in certain flocks; and we identified one case that was homozygous for phenylalanine at codon 141, a polymorphism associated with a very high risk of atypical scrapie, and 28 cases that were heterozygous at this codon.This paper presents the largest study to date on commercially-run sheep flocks naturally-infected with classical scrapie, involving 30 study flocks, more than 400 scrapie cases and over 8500 PrP genotypes. We show that some of the observed variation in epidemiological characteristics between farms is related to differences in their PrP genotype profile; although much remains unexplained and may instead be attributed to the stochastic nature of scrapie dynamics.

  13. Atypical scrapie prions from sheep and lack of disease in transgenic mice overexpressing human prion protein.

    Science.gov (United States)

    Wadsworth, Jonathan D F; Joiner, Susan; Linehan, Jacqueline M; Balkema-Buschmann, Anne; Spiropoulos, John; Simmons, Marion M; Griffiths, Peter C; Groschup, Martin H; Hope, James; Brandner, Sebastian; Asante, Emmanuel A; Collinge, John

    2013-11-01

    Public and animal health controls to limit human exposure to animal prions are focused on bovine spongiform encephalopathy (BSE), but other prion strains in ruminants may also have zoonotic potential. One example is atypical/Nor98 scrapie, which evaded statutory diagnostic methods worldwide until the early 2000s. To investigate whether sheep infected with scrapie prions could be another source of infection, we inoculated transgenic mice that overexpressed human prion protein with brain tissue from sheep with natural field cases of classical and atypical scrapie, sheep with experimental BSE, and cattle with BSE. We found that these mice were susceptible to BSE prions, but disease did not develop after prolonged postinoculation periods when mice were inoculated with classical or atypical scrapie prions. These data are consistent with the conclusion that prion disease is less likely to develop in humans after exposure to naturally occurring prions of sheep than after exposure to epizootic BSE prions of ruminants.

  14. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.

    Science.gov (United States)

    Fragkiadaki, Eirini G; Vaccari, Gabriele; Ekateriniadou, Loukia V; Agrimi, Umberto; Giadinis, Nektarios D; Chiappini, Barbara; Esposito, Elena; Conte, Michela; Nonno, Romolo

    2011-09-30

    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.

  15. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

    Directory of Open Access Journals (Sweden)

    Fragkiadaki Eirini G

    2011-09-01

    Full Text Available 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.

  16. Cloning of a Gene Whose Expression is Increased in Scrapie and in Senile Plaques in Human Brain

    Science.gov (United States)

    Wietgrefe, S.; Zupancic, M.; Haase, A.; Chesebro, B.; Race, R.; Frey, W.; Rustan, T.; Friedman, R. L.

    1985-12-01

    A complementary DNA library was constructed from messenger RNA's extracted from the brains of mice infected with the scrapie agent. The library was differentially screened with the objectives of finding clones that might be used as markers of infection and finding clones of genes whose increased expression might be correlated with the pathological changes common to scrapie and Alzheimer's disease. A gene was identified whose expression is increased in scrapie. The complementary DNA corresponding to this gene hybridized preferentially and focally to cells in the brains of scrapie-infected animals. The cloned DNA also hybridized to the neuritic plaques found with increased frequency in brains of patients with Alzheimer's disease.

  17. Rapid and discriminatory diagnosis of scrapie and BSE in retro-pharyngeal lymph nodes of sheep

    Directory of Open Access Journals (Sweden)

    van Zijderveld Fred G

    2006-06-01

    Full Text Available Abstract Background Diagnosis based on prion detection in lymph nodes of sheep and goats can improve active surveillance for scrapie and, if it were circulating, for bovine spongiform encephalopathy (BSE. With sizes that allow repetitive testing and a location that is easily accessible at slaughter, retropharyngeal lymph nodes (RLN are considered suitable organs for testing. Western blotting (WB of brain homogenates is, in principle, a technique well suited to both detect and discriminate between scrapie and BSE. In this report, WB is developed for rapid diagnosis in RLN and to study biochemical characteristics of PrPres. Results Optimal PrPres detection in RLN by WB was achieved by proper tissue processing, antibody choice and inclusion of a step for PrPresconcentration. The analyses were performed on three different sheep sources. Firstly, in a study with preclinical scrapie cases, WB of RLN from infected sheep of VRQ/VRQ genotype – VRQ represents, respectively, polymorphic PrP amino acids 136, 154, and 171 – allowed a diagnosis 14 mo earlier compared to WB of brain stem. Secondly, samples collected from sheep with confirmed scrapie in the course of passive and active surveillance programmes in the period 2002–2003 yielded positive results depending on genotype: all sheep with genotypes ARH/VRQ, VRQ/VRQ, and ARQ/VRQ scored positive for PrPres, but ARQ/ARQ and ARR/VRQ were not all positive. Thirdly, in an experimental BSE study, detection of PrPres in all 11 ARQ/ARQ sheep, including 7 preclinical cases, was possible. In all instances, WB and IHC were almost as sensitive. Moreover, BSE infection could be discriminated from scrapie infection by faster electrophoretic migration of the PrPres bands. Using dual antibody staining with selected monoclonal antibodies like 12B2 and L42, these differences in migration could be employed for an unequivocal differentiation between BSE and scrapie. With respect to glycosylation of PrPres, BSE cases

  18. Scrapie e seu diagnóstico diferencial em ovinos no Mato Grosso do Sul Scrapie and differential diagnosis in sheep in Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Héllen M. Martins

    2012-12-01

    Full Text Available Scrapie é uma doença infecciosa, neurodegenerativa fatal, causada pelo príon scrapie (PrPsc. Apresenta-se tanto na forma clássica em ovinos e caprinos geneticamente susceptíveis quanto na forma atípica em ovinos. A primeira notificação oficial do Brasil à Organização Mundial de Saúde Animal (OIE, um caso da forma clássica diagnosticado no Rio Grande do Sul ocorreu em 1985, mas a doença já havia sido diagnosticada no mesmo Estado em 1978. Este trabalho objetivou descrever dois surtos de Scrapie em ovinos em Mato Grosso do Sul (MS, Brasil e investigar, por meio de imuno-histoquímica (IHQ a presença de PrPsc no Sistema Nervoso Central (SNC de ovinos examinados entre 2003 e 2010. Na primeira parte observaram-se dois ovinos com sinais clínicos típicos de scrapie, detalhando-se os sinais neurológicos, dados epidemiológicos, histopatológicos e amostras teciduais em duplicata desses ovinos foram encaminhadas para realização de diagnóstico de Raiva e para diagnóstico IHQ para príon. Na segunda parte realizou-se levantamento de laudos de necropsia e diagnósticos histopatológicos de ovinos, no período de maio de 2003 a março de 2010. Amostras de sistema nervoso central de 51 casos foram selecionados, incluindo os dois já com diagnóstico de Scrapie mencionados acima; os tecido de todos esses ovinos foram submetidos à IHQ para detecção de proteína priônica. Os 49 ovinos avaliados apresentaram resultado negativo na IHQ para príon.Scrapie is a fatal neurodegenerative infectious disease, caused by the scrapie prion (PrPsc, that can both in the as the classic form in genetically susceptible sheep and goats and in the atypical form in sheep. The first official notification of scrapie from Brazil was made to the World Organization for Animal Health (OIE in 1985, in the state of Rio Grande do Sul, although the disease was first documented in this Brazilian state in 1978. The objective this paper was to describe two outbreaks

  19. Quantitative detection and biological propagation of scrapie seeding activity in vitro facilitate use of prions as model pathogens for disinfection.

    Directory of Open Access Journals (Sweden)

    Sandra Pritzkow

    Full Text Available Prions are pathogens with an unusually high tolerance to inactivation and constitute a complex challenge to the re-processing of surgical instruments. On the other hand, however, they provide an informative paradigm which has been exploited successfully for the development of novel broad-range disinfectants simultaneously active also against bacteria, viruses and fungi. Here we report on the development of a methodological platform that further facilitates the use of scrapie prions as model pathogens for disinfection. We used specifically adapted serial protein misfolding cyclic amplification (PMCA for the quantitative detection, on steel wires providing model carriers for decontamination, of 263K scrapie seeding activity converting normal protease-sensitive into abnormal protease-resistant prion protein. Reference steel wires carrying defined amounts of scrapie infectivity were used for assay calibration, while scrapie-contaminated test steel wires were subjected to fifteen different procedures for disinfection that yielded scrapie titre reductions of ≤10(1- to ≥10(5.5-fold. As confirmed by titration in hamsters the residual scrapie infectivity on test wires could be reliably deduced for all examined disinfection procedures, from our quantitative seeding activity assay. Furthermore, we found that scrapie seeding activity present in 263K hamster brain homogenate or multiplied by PMCA of scrapie-contaminated steel wires both triggered accumulation of protease-resistant prion protein and was further propagated in a novel cell assay for 263K scrapie prions, i.e., cerebral glial cell cultures from hamsters. The findings from our PMCA- and glial cell culture assays revealed scrapie seeding activity as a biochemically and biologically replicative principle in vitro, with the former being quantitatively linked to prion infectivity detected on steel wires in vivo. When combined, our in vitro assays provide an alternative to titrations of biological

  20. Goats singly heterozygous for PRNP S146 or K222 orally inoculated with classical scrapie at birth show no disease at ages well beyond six years

    Science.gov (United States)

    Scrapie is a transmissible spongiform encephalopathy of sheep and goats, and scrapie eradication programs in many parts of the world rely on strong genetic resistance to classical scrapie in sheep. However, the utility of putative resistance alleles in goats has been a focus of research because goat...

  1. Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds

    NARCIS (Netherlands)

    Goldmann, W.; Stewart, P.; Marier, E.; Konold, T.; Street, S.; Windl, O.; Ortiz-Pelaez, A.; Langeveld, J.

    2016-01-01

    Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes

  2. Evaluation of two commercial, rapid, ELISA kits testing or scrapie in retro-pharyngeal lymph nodes in sheep

    NARCIS (Netherlands)

    Kittelberger, R.; McIntuyre, L.; Watts, S.; MacDiarmid, S.; Hannah, M.J.; Jenner, J.; Bueno, R.; Swainsbury, R.; Langeveld, J.P.M.; Keulen, van L.J.M.; Zijderveld, van F.G.; Wemheuer, W.M.; Richt, J.A.; Sorenson, S.J.; Pigott, C.J.; O'Keefe, J.S.

    2014-01-01

    AIMS: To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN)

  3. Genetic and Pathological Follow-Up Study of Goats Experimentally and Naturally Exposed to a Sheep Scrapie Isolate

    Science.gov (United States)

    Maestrale, Caterina; Cancedda, Maria G.; Pintus, Davide; Masia, Mariangela; Nonno, Romolo; Ru, Giuseppe; Carta, Antonello; Demontis, Francesca; Santucciu, Cinzia

    2015-01-01

    ABSTRACT Thirty-seven goats carrying different prion protein genotypes (PRNP) were orally infected with a classical scrapie brain homogenate from wild-type (ARQ/ARQ) sheep and then mated to obtain 2 additional generations of offspring, which were kept in the same environment and allowed to be naturally exposed to scrapie. Occurrence of clinical or subclinical scrapie was observed in the experimentally infected goats (F0) and in only one (F1b) of the naturally exposed offspring groups. In both groups (F0 and F1b), goats carrying the R154H, H154H, R211Q, and P168Q-P240P dimorphisms died of scrapie after a longer incubation period than wild-type, G37V, Q168Q-P240P, and S240P goats. In contrast, D145D and Q222K goats were resistant to infection. The immunobiochemical signature of the scrapie isolate and its pathological aspects observed in the sheep donors were substantially maintained over 2 goat generations, i.e., after experimental and natural transmission. This demonstrates that the prion protein gene sequence, which is shared by sheep and goats, is more powerful than any possible but unknown species-related factors in determining scrapie phenotypes. With regard to genetics, our study confirms that the K222 mutation protects goats even against ovine scrapie isolates, and for the first time, a possible association of D145 mutation with scrapie resistance is shown. In addition, it is possible that the sole diverse frequencies of these genetic variants might, at least in part, shape the prevalence of scrapie among naturally exposed progenies in affected herds. IMPORTANCE This study was aimed at investigating the genetic and pathological features characterizing sheep-to-goat transmission of scrapie. We show that in goats with different prion protein gene mutations, the K222 genetic variant is associated with scrapie resistance after natural and experimental exposure to ovine prion infectivity. In addition, we observed for the first time a protective effect of the D145

  4. Detection of prions in the faeces of sheep naturally infected with classical scrapie

    Directory of Open Access Journals (Sweden)

    Terry Linda A

    2011-05-01

    Full Text Available Abstract Classical scrapie is a naturally transmitted prion disease of sheep and goats. Contaminated environments may contribute to the spread of disease and evidence from animal models has implicated urine, blood, saliva, placenta and faeces as possible sources of the infection. Here we sought to determine whether sheep naturally infected with classical scrapie shed prions in their faeces. We used serial protein misfolding cyclic amplification (sPMCA along with two extraction methods to examine faeces from sheep during both the clinical and preclinical phases of the disease and showed amplification of PrPSc in 7 of 15 and 14 of 14 sheep respectively. However PrPSc was not amplified from the faeces of 25 sheep not exposed to scrapie. These data represent the first demonstration of prion shedding in faeces from a naturally infected host and thus a likely source of prion contamination in the environment.

  5. Gene Expression Profiling and Association with Prion-Related Lesions in the Medulla Oblongata of Symptomatic Natural Scrapie Animals

    Science.gov (United States)

    Filali, Hicham; Martin-Burriel, Inmaculada; Harders, Frank; Varona, Luis; Lyahyai, Jaber; Zaragoza, Pilar; Pumarola, Martí; Badiola, Juan J.; Bossers, Alex; Bolea, Rosa

    2011-01-01

    The pathogenesis of natural scrapie and other prion diseases remains unclear. Examining transcriptome variations in infected versus control animals may highlight new genes potentially involved in some of the molecular mechanisms of prion-induced pathology. The aim of this work was to identify disease-associated alterations in the gene expression profiles of the caudal medulla oblongata (MO) in sheep presenting the symptomatic phase of natural scrapie. The gene expression patterns in the MO from 7 sheep that had been naturally infected with scrapie were compared with 6 controls using a Central Veterinary Institute (CVI) custom designed 4×44K microarray. The microarray consisted of a probe set on the previously sequenced ovine tissue library by CVI and was supplemented with all of the Ovis aries transcripts that are currently publicly available. Over 350 probe sets displayed greater than 2-fold changes in expression. We identified 148 genes from these probes, many of which encode proteins that are involved in the immune response, ion transport, cell adhesion, and transcription. Our results confirm previously published gene expression changes that were observed in murine models with induced scrapie. Moreover, we have identified new genes that exhibit differential expression in scrapie and could be involved in prion neuropathology. Finally, we have investigated the relationship between gene expression profiles and the appearance of the main scrapie-related lesions, including prion protein deposition, gliosis and spongiosis. In this context, the potential impacts of these gene expression changes in the MO on scrapie development are discussed. PMID:21629698

  6. Detection of PrPres in genetically susceptible fetuses from sheep with natural scrapie.

    Directory of Open Access Journals (Sweden)

    María Carmen Garza

    Full Text Available Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and has rarely been studied. Recently, the use of the protein misfolding cyclic amplification technique (PMCA has allowed prion detection in various tissues and excretions in which PrPres levels have been undetectable by traditional assays. The main goal of this study was to detect PrPres in fetal tissues and the amniotic fluid from natural scrapie infected ewes using the PMCA technique. Six fetuses from three infected pregnant ewes in an advanced clinical stage of the disease were included in the study. From each fetus, amniotic fluid, brain, spleen, ileo-cecal valve and retropharyngeal lymph node samples were collected and analyzed using Western blotting and PMCA. Although all samples were negative using Western blotting, PrPres was detected after in vitro amplification. Our results represent the first time the biochemical detection of prions in fetal tissues, suggesting that the in utero transmission of scrapie in natural infected sheep might be possible.

  7. A Case–Control Study on the Origin of Atypical Scrapie in Sheep, France

    Science.gov (United States)

    Morignat, Eric; Ducrot, Christian; Calavas, Didier

    2009-01-01

    A matched case–control study (95 cases and 220 controls) was designed to study risk factors for atypical scrapie in sheep in France. We analyzed contacts with animals from other flocks, lambing and feeding practices, and exposure to toxic substances. Data on the prnp genotype were collected for some case and control animals and included in a complementary analysis. Sheep dairy farms had a higher risk for scrapie (odds ratio [OR] 15.1, 95% confidence interval [CI] 3.3–69.7). Lower risk was associated with organic farms (OR 0.15, 95% CI 0.02–1.26), feeding corn silage (OR 0.16, 95% CI 0.05–0.53), and feeding vitamin and mineral supplements (OR 0.6, 95% CI 0.32–1.14). Genetic effects were quantitatively important but only marginally changed estimates of other variables. We did not find any risk factor associated with an infectious origin of scrapie. Atypical scrapie could be a spontaneous disease influenced by genetic and metabolic factors. PMID:19402956

  8. Dynamics of a scrapie outbreak in a flock of Romanov sheep-estimation of transmission parameters

    NARCIS (Netherlands)

    Hagenaars, T.H.J.; Donelly, C.A.; Ferguson, N.M.; Anderson, R.M.

    2003-01-01

    Knowledge of epidemiological mechanisms and parameters underlying scrapie transmission in sheep flocks remains very limited at present. Here we introduce a method for fitting stochastic transmission models to outbreak data to estimate bounds on key transmission parameters. We apply this method to

  9. Screening of intact yeasts and cell extracts to reduce Scrapie prions during biotransformation of food waste.

    Science.gov (United States)

    Huyben, David; Boqvist, Sofia; Passoth, Volkmar; Renström, Lena; Allard Bengtsson, Ulrika; Andréoletti, Olivier; Kiessling, Anders; Lundh, Torbjörn; Vågsholm, Ivar

    2018-02-08

    Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce prion activity during the biotransformation of waste substrates-thereby becoming a biosafety hurdle in such a circular food system. During pre-screening, 30 yeast isolates were spiked with Classical Scrapie prions and incubated for 72 h in casein substrate, as a waste substitute. Based on reduced Scrapie seeding activity, waste biotransformation and protease activities, intact cells and cell extracts of 10 yeasts were further tested. Prion analysis showed that five yeast species reduced Scrapie seeding activity by approximately 1 log10 or 90%. Cryptococcus laurentii showed the most potential to reduce prion activity since both intact and extracted cells reduced Scrapie by 1 log10 and achieved the highest protease activity. These results show that select forms of yeast can act as a prion hurdle during the biotransformation of waste. However, the limited ability of yeasts to reduce prion activity warrants caution as a sole barrier to transmission as higher log reductions are needed before using waste-cultured yeast in circular food systems.

  10. Medulla oblongata transcriptome changes during presymptomatic natural scrapie and their associaition with prion-related lesions.

    NARCIS (Netherlands)

    Filali, H.; Martin-Burriel, I.; Harders, F.; Varona, L.; Serrano, C.; Acín, C.; Badiola, J.J.; Bossers, A.; Bolea, R.

    2012-01-01

    Background The pathogenesis of natural scrapie and other prion diseases is still poorly understood. Determining the variations in the transcriptome in the early phases of the disease might clarify some of the molecular mechanisms of the prion-induced pathology and allow for the development of new

  11. Determining the relative susceptibility of four prion protein genotypes to atypical scrapie

    Science.gov (United States)

    Atypical scrapie is a sheep prion (PrPSc) disease whose epidemiology is consistent with a sporadic origin and is associated with specific polymorphisms of the normal cellular prion protein (PrPC). We describe a mass spectrometry-based method of detecting and quantifying the polymorphisms of sheep P...

  12. Intraepithelial and interstitial deposition of pathological prion protein in kidneys of scrapie-affected sheep.

    Directory of Open Access Journals (Sweden)

    Ciriaco Ligios

    Full Text Available Prions have been documented in extra-neuronal and extra-lymphatic tissues of humans and various ruminants affected by Transmissible Spongiform Encephalopathy (TSE. The presence of prion infectivity detected in cervid and ovine blood tempted us to reason that kidney, the organ filtrating blood derived proteins, may accumulate disease associated PrP(Sc. We collected and screened kidneys of experimentally, naturally scrapie-affected and control sheep for renal deposition of PrP(Sc from distinct, geographically separated flocks. By performing Western blot, PET blot analysis and immunohistochemistry we found intraepithelial (cortex, medulla and papilla and occasional interstitial (papilla deposition of PrP(Sc in kidneys of scrapie-affected sheep. Interestingly, glomerula lacked detectable signals indicative of PrP(Sc. PrP(Sc was also detected in kidneys of subclinical sheep, but to significantly lower degree. Depending on the stage of the disease the incidence of PrP(Sc in kidney varied from approximately 27% (subclinical to 73.6% (clinical in naturally scrapie-affected sheep. Kidneys from flocks without scrapie outbreak were devoid of PrP(Sc. Here we demonstrate unexpectedly frequent deposition of high levels of PrP(Sc in ovine kidneys of various flocks. Renal deposition of PrP(Sc is likely to be a pre-requisite enabling prionuria, a possible co-factor of horizontal prion-transmission in sheep.

  13. Deletion of protease-activated receptor 2 prolongs survival of scrapie-inoculated mice

    Czech Academy of Sciences Publication Activity Database

    Matěj, R.; Olejár, Tomáš; Janoušková, O.; Holada, K.

    2012-01-01

    Roč. 93, č. 9 (2012), s. 2057-2061 ISSN 0022-1317 Institutional support: RVO:67985823 Keywords : protease-activated receptor (PAR2) * scrapie * neurodegenerative disorders Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.127, year: 2012

  14. Scrapie e seu diagnóstico diferencial em ovinos no Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Héllen M. Martins

    2012-12-01

    Full Text Available Scrapie é uma doença infecciosa, neurodegenerativa fatal, causada pelo príon scrapie (PrPsc. Apresenta-se tanto na forma clássica em ovinos e caprinos geneticamente susceptíveis quanto na forma atípica em ovinos. A primeira notificação oficial do Brasil à Organização Mundial de Saúde Animal (OIE, um caso da forma clássica diagnosticado no Rio Grande do Sul ocorreu em 1985, mas a doença já havia sido diagnosticada no mesmo Estado em 1978. Este trabalho objetivou descrever dois surtos de Scrapie em ovinos em Mato Grosso do Sul (MS, Brasil e investigar, por meio de imuno-histoquímica (IHQ a presença de PrPsc no Sistema Nervoso Central (SNC de ovinos examinados entre 2003 e 2010. Na primeira parte observaram-se dois ovinos com sinais clínicos típicos de scrapie, detalhando-se os sinais neurológicos, dados epidemiológicos, histopatológicos e amostras teciduais em duplicata desses ovinos foram encaminhadas para realização de diagnóstico de Raiva e para diagnóstico IHQ para príon. Na segunda parte realizou-se levantamento de laudos de necropsia e diagnósticos histopatológicos de ovinos, no período de maio de 2003 a março de 2010. Amostras de sistema nervoso central de 51 casos foram selecionados, incluindo os dois já com diagnóstico de Scrapie mencionados acima; os tecido de todos esses ovinos foram submetidos à IHQ para detecção de proteína priônica. Os 49 ovinos avaliados apresentaram resultado negativo na IHQ para príon.

  15. Medulla oblongata transcriptome changes during presymptomatic natural scrapie and their association with prion-related lesions.

    Science.gov (United States)

    Filali, Hicham; Martin-Burriel, Inmaculada; Harders, Frank; Varona, Luis; Serrano, Carmen; Acín, Cristina; Badiola, Juan J; Bossers, Alex; Bolea, Rosa

    2012-08-16

    The pathogenesis of natural scrapie and other prion diseases is still poorly understood. Determining the variations in the transcriptome in the early phases of the disease might clarify some of the molecular mechanisms of the prion-induced pathology and allow for the development of new biomarkers for diagnosis and therapy. This study is the first to focus on the identification of genes regulated during the preclinical phases of natural scrapie in the ovine medulla oblongata (MO) and the association of these genes with prion deposition, astrocytosis and spongiosis. A custom microarray platform revealed that 86 significant probes had expression changes greater than 2-fold. From these probes, we identified 32 genes with known function; the highest number of regulated genes was included in the phosphoprotein-encoding group. Genes encoding extracellular marker proteins and those involved in the immune response and apoptosis were also differentially expressed. In addition, we investigated the relationship between the gene expression profiles and the appearance of the main scrapie-associated brain lesions. Quantitative Real-time PCR was used to validate the expression of some of the regulated genes, thus showing the reliability of the microarray hybridization technology. Genes involved in protein and metal binding and oxidoreductase activity were associated with prion deposition. The expression of glial fibrillary acidic protein (GFAP) was associated with changes in the expression of genes encoding proteins with oxidoreductase and phosphatase activity, and the expression of spongiosis was related to genes encoding extracellular matrix components or transmembrane transporters. This is the first genome-wide expression study performed in naturally infected sheep with preclinical scrapie. As in previous studies, our findings confirm the close relationship between scrapie and other neurodegenerative diseases.

  16. Changes in HSP gene and protein expression in natural scrapie with brain damage

    Science.gov (United States)

    2011-01-01

    Heat shock proteins (Hsp) perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease. PMID:21314976

  17. Changes in HSP gene and protein expression in natural scrapie with brain damage

    Directory of Open Access Journals (Sweden)

    Serrano Carmen

    2011-01-01

    Full Text Available Abstract Heat shock proteins (Hsp perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease.

  18. Resistance to classical scrapie in experimentally challenged goats carrying mutation K222 of the prion protein gene

    Directory of Open Access Journals (Sweden)

    Acutis Pier Luigi

    2012-02-01

    Full Text Available 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.

  19. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

    OpenAIRE

    Fragkiadaki Eirini G; Vaccari Gabriele; Ekateriniadou Loukia V; Agrimi Umberto; Giadinis Nektarios D; Chiappini Barbara; Esposito Elena; Conte Michela; Nonno Romolo

    2011-01-01

    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 ...

  20. Comparison of strategies for substantiating freedom from scrapie in a sheep flock.

    Science.gov (United States)

    Durand, Benoit; Martinez, Marie-José; Calavas, Didier; Ducrot, Christian

    2009-04-30

    The public health threat represented by a potential circulation of bovine spongiform encephalopathy agent in sheep population has led European animal health authorities to launch large screening and genetic selection programmes. If demonstrated, such a circulation would have dramatic economic consequences for sheep breeding sector. In this context, it is important to evaluate the feasibility of qualification procedures that would allow sheep breeders demonstrating their flock is free from scrapie. Classical approaches, based on surveys designed to detect disease presence, do not account for scrapie specificities: the genetic variations of susceptibility and the absence of live diagnostic test routinely available. Adapting these approaches leads to a paradoxical situation in which a greater amount of testing is needed to substantiate disease freedom in genetically resistant flocks than in susceptible flocks, whereas probability of disease freedom is a priori higher in the former than in the latter. The goal of this study was to propose, evaluate and compare several qualification strategies for demonstrating a flock is free from scrapie. A probabilistic framework was defined that accounts for scrapie specificities and allows solving the preceding paradox. Six qualification strategies were defined that combine genotyping data, diagnostic tests results and flock pedigree. These were compared in two types of simulated flocks: resistant and susceptible flocks. Two strategies allowed demonstrating disease freedom in several years, for the majority of simulated flocks: a strategy in which all the flock animals are genotyped, and a strategy in which only founders animals are genotyped, the flock pedigree being known. In both cases, diagnostic tests are performed on culled animals. The less costly strategy varied according to the genetic context (resistant or susceptible) and to the relative costs of a genotyping exam and of a diagnostic test. This work demonstrates that

  1. Short-term study of the uptake of PrPSc by the Peyer’s patches in hamsters after oral exposure to scrapie

    DEFF Research Database (Denmark)

    Bergström, Ann-Louise; Jensen, Tim Kåre; Heegaard, Peter M. H.

    2006-01-01

    The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post-infection. To ......The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post...

  2. Scrapie infectivity is quickly cleared in tissues of orally-infected farmed fish

    OpenAIRE

    Ingrosso, Loredana; Novoa, Beatriz; Valle, Andrea Z Dalla; Cardone, Franco; Aranguren, Raquel; Sbriccoli, Marco; Bevivino, Simona; Iriti, Marcello; Liu, Quanguo; Vetrugno, Vito; Lu, Mei; Faoro, Franco; Ciappellano, Salvatore; Figueras, Antonio; Pocchiari, Maurizio

    2006-01-01

    Abstract Background Scrapie and bovine spongiform encephalopathy (BSE) belongs to the group of animal transmissible spongiform encephalopathy (TSE). BSE epidemic in the UK and elsewhere in Europe has been linked to the use of bovine meat and bone meals (MBM) in the feeding of cattle. There is concern that pigs, poultry and fish bred for human consumption and fed with infected MBM would eventually develop BSE or carry residual infectivity without disease. Although there has been no evidence of...

  3. Scrapie affects the maturation cycle and immune complex trapping by follicular dendritic cells in mice.

    Directory of Open Access Journals (Sweden)

    Gillian McGovern

    2009-12-01

    Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases are infectious neurological disorders of man and animals, characterised by abnormal disease-associated prion protein (PrP(d accumulations in the brain and lymphoreticular system (LRS. Prior to neuroinvasion, TSE agents often accumulate to high levels within the LRS, apparently without affecting immune function. However, our analysis of scrapie-affected sheep shows that PrP(d accumulations within the LRS are associated with morphological changes to follicular dendritic cells (FDCs and tingible body macrophages (TBMs. Here we examined FDCs and TBMs in the mesenteric lymph nodes (MLNs of scrapie-affected mice by light and electron microscopy. In MLNs from uninfected mice, FDCs could be morphologically categorised into immature, mature and regressing forms. However, in scrapie-affected MLNs this maturation cycle was adversely affected. FDCs characteristically trap and retain immune complexes on their surfaces, which they display to B-lymphocytes. In scrapie-affected MLNs, some FDCs were found where areas of normal and abnormal immune complex retention occurred side by side. The latter co-localised with PrP(d plasmalemmal accumulations. Our data suggest this previously unrecognised morphology represents the initial stage of an abnormal FDC maturation cycle. Alterations to the FDCs included PrP(d accumulation, abnormal cell membrane ubiquitin and excess immunoglobulin accumulation. Regressing FDCs, in contrast, appeared to lose their membrane-attached PrP(d. Together, these data suggest that TSE infection adversely affects the maturation and regression cycle of FDCs, and that PrP(d accumulation is causally linked to the abnormal pathology observed. We therefore support the hypothesis that TSEs cause an abnormality in immune function.

  4. A bovine cell line that can be infected by natural sheep scrapie prions.

    Directory of Open Access Journals (Sweden)

    Anja M Oelschlegel

    Full Text Available Cell culture systems represent a crucial part in basic prion research; yet, cell lines that are susceptible to prions, especially to field isolated prions that were not adapted to rodents, are very rare. The purpose of this study was to identify and characterize a cell line that was susceptible to ruminant-derived prions and to establish a stable prion infection within it. Based on species and tissue of origin as well as PrP expression rate, we pre-selected a total of 33 cell lines that were then challenged with natural and with mouse propagated BSE or scrapie inocula. Here, we report the successful infection of a non-transgenic bovine cell line, a sub-line of the bovine kidney cell line MDBK, with natural sheep scrapie prions. This cell line retained the scrapie infection for more than 200 passages. Selective cloning resulted in cell populations with increased accumulation of PrPres, although this treatment was not mandatory for retaining the infection. The infection remained stable, even under suboptimal culture conditions. The resulting infectivity of the cells was confirmed by mouse bioassay (Tgbov mice, Tgshp mice. We believe that PES cells used together with other prion permissive cell lines will prove a valuable tool for ongoing efforts to understand and defeat prions and prion diseases.

  5. Quantitating PrP Polymorphisms Present in Prions from Heterozygous Scrapie-Infected Sheep.

    Science.gov (United States)

    Silva, Christopher J; Erickson-Beltran, Melissa L; Hui, Colleen; Badiola, Juan José; Nicholson, Eric M; Requena, Jesús R; Bolea, Rosa

    2017-01-03

    Scrapie is a prion (PrP Sc ) disease of sheep. The incubation period of sheep scrapie is strongly influenced by polymorphisms at positions 136, 154, and 171 of a sheep's normal cellular prion protein (PrP C ). Chymotrypsin was used to digest sheep recombinant PrP to identify a set of characteristic peptides [M 132 LGSXMSRPL 141 (X = A or V), Y 153 XENMY 158 (X,= H or R), and Y 166 RPVDXY 172 (X = H, K, Q, or R)] that could be used to detect and quantitate polymorphisms at positions 136, 154, and 171 of sheep PrP C or PrP Sc . These peptides were used to develop a multiple reaction monitoring method (MRM) to detect the amounts of a particular polymorphism in a sample of PrP Sc isolated from sheep heterozygous for their PrP C proteins. The limit of detection for these peptides was less than 50 attomole. Spinal cord tissue from heterozygous (ARQ/VRQ or ARH/ARQ) scrapie-infected Rasa Aragonesa sheep was analyzed using this MRM method. Both sets of heterozygotes show the presence of both polymorphisms in PrP Sc . This was true for samples containing both proteinase K (PK)-sensitive and PK-resistant PrP Sc and samples containing only the PK-resistant PrP Sc . These results show that heterozygous animals contain PrP Sc that is composed of significant amounts of both PrP polymorphisms.

  6. Predicting the impact of selection for scrapie resistance on PRNP genotype frequencies in goats.

    Science.gov (United States)

    Sacchi, Paola; Rasero, Roberto; Ru, Giuseppe; Aiassa, Eleonora; Colussi, Silvia; Ingravalle, Francesco; Peletto, Simone; Perrotta, Maria Gabriella; Sartore, Stefano; Soglia, Dominga; Acutis, Pierluigi

    2018-03-06

    The European Union has implemented breeding programmes to increase scrapie resistance in sheep. A similar approach can be applied also in goats since the K222 allele provides a level of resistance equivalent to that of ARR in sheep. The European Food Safety Authority stated that breeding for resistance could be offered as an option for Member States to control classical scrapie in goats. We assessed the impact of different breeding strategies on PRNP genotype frequencies using a mathematical model that describes in detail the evolution of K222 in two goat breeds, Chamois Coloured and Saanen. Different patterns of age structure and replacement rate were modelled as factors affecting response to selection. Breeding for scrapie resistance can be implemented in goats, even though the initial K222 frequencies in these breeds are not particularly favourable and the rate at which the resistant animals increase, both breeding and slaughtered for meat production, is slow. If the goal is not to achieve the fixation of resistance allele, it is advisable to carry out selection only until a desired frequency of K222-carriers has been attained. Nucleus selection vs. selection on the overall populations is less expensive but takes longer to reach the desired output. The programme performed on the two goat breeds serves as a model of the response the selection could have in other breeds that show different initial frequencies and population structure. In this respect, the model has a general applicability.

  7. Scrapie infectivity is quickly cleared in tissues of orally-infected farmed fish

    Directory of Open Access Journals (Sweden)

    Faoro Franco

    2006-06-01

    Full Text Available Abstract Background Scrapie and bovine spongiform encephalopathy (BSE belongs to the group of animal transmissible spongiform encephalopathy (TSE. BSE epidemic in the UK and elsewhere in Europe has been linked to the use of bovine meat and bone meals (MBM in the feeding of cattle. There is concern that pigs, poultry and fish bred for human consumption and fed with infected MBM would eventually develop BSE or carry residual infectivity without disease. Although there has been no evidence of infection in these species, experimental data on the susceptibility to the BSE agent of farm animals other than sheep and cow are limited only to pigs and domestic chicken. In the framework of a EU-granted project we have challenged two species of fish largely used in human food consumption, rainbow trout (Oncorhynchus mykiss and turbot (Scophthalmus maximus, with a mouse-adapted TSE strain (scrapie 139A, to assess the risk related to oral consumption of TSE contaminated food. In trout, we also checked the "in vitro" ability of the pathological isoform of the mouse prion protein (PrPSc to cross the intestinal epithelium when added to the mucosal side of everted intestine. Results Fish challenged with a large amount of scrapie mouse brain homogenate by either oral or parenteral routes, showed the ability to clear the majority of infectivity load. None of the fish tissues taken at different time points after oral or parenteral inoculation was able to provoke scrapie disease after intracerebral inoculation in recipient mice. However, a few recipient mice were positive for PrPSc and spongiform lesions in the brain. We also showed a specific binding of PrPSc to the mucosal side of fish intestine in the absence of an active uptake of the prion protein through the intestinal wall. Conclusion These results indicate that scrapie 139A, and possibly BSE, is quickly removed from fish tissues despite evidence of a prion like protein in fish and of a specific binding of Pr

  8. Lack of prion accumulation in lymphoid tissues of PRNP ARQ/ARR sheep intracranially inoculated with the agent of scrapie.

    Science.gov (United States)

    Greenlee, Justin J; Kunkle, Robert A; Richt, Jürgen A; Nicholson, Eric M; Hamir, Amir N

    2014-01-01

    Sheep scrapie is a transmissible spongiform encephalopathy that can be transmitted horizontally. The prion protein gene (PRNP) profoundly influences the susceptibility of sheep to the scrapie agent and the tissue levels and distribution of PrPSc in affected sheep. The purpose of this study was to compare the survival time and PrPSc tissue distribution in sheep with highly resistant and highly susceptible PRNP genotypes after intracranial inoculation of the agent of scrapie. Five sheep each of genotype VRQ/VRQ, VRQ/ARR or ARQ/ARR were inoculated. Sheep were euthanized when clinical signs of scrapie became severe. Clinical signs, microscopic lesions, and western blot profiles were uniform across genotypes and consistent with manifestations of classical scrapie. Mean survival time differences were associated with the 171 polymorphic site with VRQ/VRQ sheep surviving 18 months, whereas VRQ/ARR and ARQ/ARR sheep survived 60 and 56 months, respectively. Labeling of PrPSc by immunohistochemistry revealed similar accumulations in central nervous system tissues regardless of host genotype. Immunoreactivity for PrPSc in lymphoid tissue was consistently abundant in VRQ/VRQ, present but confined to tonsil or retropharyngeal lymph node in 4/5 VRQ/ARR, and totally absent in ARQ/ARR sheep. The results of this study demonstrate the susceptibility of sheep with the ARQ/ARR genotype to scrapie by the intracranial inoculation route with PrPSc accumulation in CNS tissues, but prolonged incubation times and lack of PrPSc in lymphoid tissue.

  9. White blood cell-based detection of asymptomatic scrapie infection by ex vivo assays.

    Directory of Open Access Journals (Sweden)

    Sophie Halliez

    Full Text Available Prion transmission can occur by blood transfusion in human variant Creutzfeldt-Jakob disease and in experimental animal models, including sheep. Screening of blood and its derivatives for the presence of prions became therefore a major public health issue. As infectious titer in blood is reportedly low, highly sensitive and robust methods are required to detect prions in blood and blood derived products. The objectives of this study were to compare different methods--in vitro, ex vivo and in vivo assays--to detect prion infectivity in cells prepared from blood samples obtained from scrapie infected sheep at different time points of the disease. Protein misfolding cyclic amplification (PMCA and bioassays in transgenic mice expressing the ovine prion protein were the most efficient methods to identify infected animals at any time of the disease (asymptomatic to terminally-ill stages. However scrapie cell and cerebellar organotypic slice culture assays designed to replicate ovine prions in culture also allowed detection of prion infectivity in blood cells from asymptomatic sheep. These findings confirm that white blood cells are appropriate targets for preclinical detection and introduce ex vivo tools to detect blood infectivity during the asymptomatic stage of the disease.

  10. Enzymatic formulation capable of degrading scrapie prion under mild digestion conditions.

    Directory of Open Access Journals (Sweden)

    Emeka A Okoroma

    Full Text Available The prion agent is notoriously resistant to common proteases and conventional sterilisation procedures. The current methods known to destroy prion infectivity such as incineration, alkaline and thermal hydrolysis are harsh, destructive, environmentally polluting and potentially hazardous, thus limit their applications for decontamination of delicate medical and laboratory devices, remediation of prion contaminated environment and for processing animal by-products including specified risk materials and carcases. Therefore, an environmentally friendly, non-destructive enzymatic degradation approach is highly desirable. A feather-degrading Bacillus licheniformis N22 keratinase has been isolated which degraded scrapie prion to undetectable level of PrP(Sc signals as determined by Western Blot analysis. Prion infectivity was verified by ex vivo cell-based assay. An enzymatic formulation combining N22 keratinase and biosurfactant derived from Pseudomonas aeruginosa degraded PrP(Sc at 65 °C in 10 min to undetectable level -. A time-course degradation analysis carried out at 50 °C over 2 h revealed the progressive attenuation of PrP(Sc intensity. Test of residual infectivity by standard cell culture assay confirmed that the enzymatic formulation reduced PrP(Sc infectivity to undetectable levels as compared to cells challenged with untreated standard scrapie sheep prion (SSBP/1 (p-value = 0.008 at 95% confidence interval. This novel enzymatic formulation has significant potential application for prion decontamination in various environmentally friendly systems under mild treatment conditions.

  11. Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats

    OpenAIRE

    Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P. M.; Ekateriniadou, Loukia V.; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

    2017-01-01

    The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres s...

  12. Caprine prion genen polymorphisms are associated with decreased incidence of classical scrapie in goat herds in the United Kingdom.

    NARCIS (Netherlands)

    Goldmann, W.; Ryan, K.; Stewart, P.; Parnham, D.; Xicohtencatl, R.; Fernandez, N.; Saunders, G.; Windl, O.; Gonzalez, L.; Bossers, A.

    2011-01-01

    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

  13. 9 CFR 54.11 - Approval of laboratories to run official scrapie tests and official genotype tests.

    Science.gov (United States)

    2010-01-01

    ... request approval to conduct one or more types of scrapie test or genotype test on one or more types of... type of test and for each type of tissue for which they request approval. (c) The Administrator may... the laboratory and shall give the director an opportunity to respond. If there are conflicts as to any...

  14. Gene expression profiling en association with prion-related lesions in the medulla oblongata of symptomatic natural scrapie animals.

    NARCIS (Netherlands)

    Filali, H.; Martin-Burriel, I.; Harders, F.; Varona, L.; Lyahyai, J.; Zaragoza, P.; Pumarola, M.; Badiola, J.J.; Bossers, A.; Bolea, R.

    2011-01-01

    The pathogenesis of natural scrapie and other prion diseases remains unclear. Examining transcriptome variations in infected versus control animals may highlight new genes potentially involved in some of the molecular mechanisms of prion-induced pathology. The aim of this work was to identify

  15. Scrapie susceptibility-linked polymorphisms modulate the in vitro conversion of sheep prion protein to protease-resistant forms

    NARCIS (Netherlands)

    Bossers, A.; Belt, P.B.G.M.; Raymond, G.J.; Caughey, B.; Vries, de R.; Smits, M.

    1997-01-01

    Prion diseases are natural transmissible neurodegenerative disorders in humans and animals. They are characterized by the accumulation of a protease-resistant scrapie-associated prion protein (PrPSc) of the host-encoded cellular prion protein (PrPC) mainly in the central nervous system.

  16. Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats.

    Science.gov (United States)

    Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P M; Ekateriniadou, Loukia V; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

    2017-07-01

    The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres seems to be formed nearly totally by the 222Q variant provides evidence that the 222K PrP variant confers resistance to conversion to PrPres formation and reinforces the view that this mutation has a protective role against classical scrapie in goats.

  17. Selective propagation of mouse-passaged scrapie prions with long incubation period from a mixed prion population using GT1-7 cells.

    Directory of Open Access Journals (Sweden)

    Kohtaro Miyazawa

    Full Text Available In our previous study, we demonstrated the propagation of mouse-passaged scrapie isolates with long incubation periods (L-type derived from natural Japanese sheep scrapie cases in murine hypothalamic GT1-7 cells, along with disease-associated prion protein (PrPSc accumulation. We here analyzed the susceptibility of GT1-7 cells to scrapie prions by exposure to infected mouse brains at different passages, following interspecies transmission. Wild-type mice challenged with a natural sheep scrapie case (Kanagawa exhibited heterogeneity of transmitted scrapie prions in early passages, and this mixed population converged upon one with a short incubation period (S-type following subsequent passages. However, when GT1-7 cells were challenged with these heterologous samples, L-type prions became dominant. This study demonstrated that the susceptibility of GT1-7 cells to L-type prions was at least 105 times higher than that to S-type prions and that L-type prion-specific biological characteristics remained unchanged after serial passages in GT1-7 cells. This suggests that a GT1-7 cell culture model would be more useful for the economical and stable amplification of L-type prions at the laboratory level. Furthermore, this cell culture model might be used to selectively propagate L-type scrapie prions from a mixed prion population.

  18. Explaining the heterogeneous scrapie surveillance figures across Europe: a meta-regression approach

    Directory of Open Access Journals (Sweden)

    Ru Giuseppe

    2007-06-01

    Full Text Available Abstract Background Two annual surveys, the abattoir and the fallen stock, monitor the presence of scrapie across Europe. A simple comparison between the prevalence estimates in different countries reveals that, in 2003, the abattoir survey appears to detect more scrapie in some countries. This is contrary to evidence suggesting the greater ability of the fallen stock survey to detect the disease. We applied meta-analysis techniques to study this apparent heterogeneity in the behaviour of the surveys across Europe. Furthermore, we conducted a meta-regression analysis to assess the effect of country-specific characteristics on the variability. We have chosen the odds ratios between the two surveys to inform the underlying relationship between them and to allow comparisons between the countries under the meta-regression framework. Baseline risks, those of the slaughtered populations across Europe, and country-specific covariates, available from the European Commission Report, were inputted in the model to explain the heterogeneity. Results Our results show the presence of significant heterogeneity in the odds ratios between countries and no reduction in the variability after adjustment for the different risks in the baseline populations. Three countries contributed the most to the overall heterogeneity: Germany, Ireland and The Netherlands. The inclusion of country-specific covariates did not, in general, reduce the variability except for one variable: the proportion of the total adult sheep population sampled as fallen stock by each country. A large residual heterogeneity remained in the model indicating the presence of substantial effect variability between countries. Conclusion The meta-analysis approach was useful to assess the level of heterogeneity in the implementation of the surveys and to explore the reasons for the variation between countries.

  19. Dysfunction of mitochondrial dynamics in the brains of scrapie-infected mice

    International Nuclear Information System (INIS)

    Choi, Hong-Seok; Choi, Yeong-Gon; Shin, Hae-Young; Oh, Jae-Min; Park, Jeong-Ho; Kim, Jae-Il; Carp, Richard I.; Choi, Eun-Kyoung; Kim, Yong-Sun

    2014-01-01

    Highlights: • Mfn1 and Fis1 are significantly increased in the hippocampal region of the ME7 prion-infected brain, whereas Dlp1 is significantly decreased in the infected brain. • Dlp1 is significantly decreased in the cytosolic fraction of the hippocampus in the infected brain. • Neuronal mitochondria in the prion-infected brains are enlarged and swollen compared to those of control brains. • There are significantly fewer mitochondria in the ME7-infected brain compared to the number in control brain. - Abstract: Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress in scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the

  20. Membrane toxicity of abnormal prion protein in adrenal chromaffin cells of scrapie infected sheep.

    Directory of Open Access Journals (Sweden)

    Gillian McGovern

    Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases are associated with accumulations of disease specific PrP (PrP(d in the central nervous system (CNS and often the lymphoreticular system (LRS. Accumulations have additionally been recorded in other tissues including the peripheral nervous system and adrenal gland. Here we investigate the effect of sheep scrapie on the morphology and the accumulation of PrP(d in the adrenal medulla of scrapie affected sheep using light and electron microscopy. Using immunogold electron microscopy, non-fibrillar forms of PrP(d were shown to accumulate mainly in association with chromaffin cells, occasional nerve endings and macrophages. PrP(d accumulation was associated with distinctive membrane changes of chromaffin cells including increased electron density, abnormal linearity and invaginations. Internalisation of PrP(d from the chromaffin cell plasma membrane occurred in association with granule recycling following hormone exocytosis. PrP(d accumulation and internalisation from membranes is similarly associated with perturbations of membrane structure and trafficking in CNS neurons and tingible body macrophages of the LRS. These data suggest that a major toxic effect of PrP(d is at the level of plasma membranes. However, the precise nature of PrP(d-membrane toxicity is tissue and cell specific suggesting that the normal protein may act as a multi-functional scaffolding molecule. We further suggest that the co-localisation of PrP(d with exocytic granules of the hormone trafficking system may provide an additional source of infectivity in blood.

  1. Dysfunction of mitochondrial dynamics in the brains of scrapie-infected mice

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong-Seok [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Choi, Yeong-Gon; Shin, Hae-Young; Oh, Jae-Min [Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Park, Jeong-Ho [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Kim, Jae-Il [Department of Food Science and Nutrition, Pukyong National University, 599-1 Daeyeon-3-dong, Nam-gu, Busan 608-737 (Korea, Republic of); Carp, Richard I. [New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314 (United States); Choi, Eun-Kyoung, E-mail: ekchoi@hallym.ac.kr [Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Kim, Yong-Sun, E-mail: yskim@hallym.ac.kr [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of)

    2014-05-30

    Highlights: • Mfn1 and Fis1 are significantly increased in the hippocampal region of the ME7 prion-infected brain, whereas Dlp1 is significantly decreased in the infected brain. • Dlp1 is significantly decreased in the cytosolic fraction of the hippocampus in the infected brain. • Neuronal mitochondria in the prion-infected brains are enlarged and swollen compared to those of control brains. • There are significantly fewer mitochondria in the ME7-infected brain compared to the number in control brain. - Abstract: Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress in scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the

  2. Accumulation and dissemination of prion protein in experimental sheep scrapie in the natural host

    Directory of Open Access Journals (Sweden)

    Warner Richard

    2009-02-01

    Full Text Available Abstract Background In order to study the sites of uptake and mechanisms of dissemination of scrapie prions in the natural host under controlled conditions, lambs aged 14 days and homozygous for the VRQ allele of the PrP gene were infected by the oral route. Infection occurred in all lambs with a remarkably short and highly consistent incubation period of approximately 6 months. Challenge of lambs at approximately eight months of age resulted in disease in all animals, but with more variable incubation periods averaging significantly longer than those challenged at 14 days. This model provides an excellent system in which to study the disease in the natural host by virtue of the relatively short incubation period and close resemblance to natural infection. Results Multiple sites of prion uptake were identified, of which the most important was the Peyer's patch of the distal ileum. Neuroinvasion was detected initially in the enteric nervous system prior to infection of the central nervous system. At end stage disease prion accumulation was widespread throughout the entire neuraxis, but vacuolar pathology was absent in most animals that developed disease at 6–7 months of age. Conclusion Initial spread of detectable PrP was consistent with drainage in afferent lymph to dependent lymph nodes. Subsequent accumulation of prions in lymphoid tissue not associated with the gut is consistent with haematogenous spread. In addition to macrophages and follicular dendritic cells, prion containing cells consistent with afferent lymph dendritic cells were identified and are suggested as a likely vehicle for carriage of prions from initial site of uptake to the lymphoreticular system, and as potential carriers of prion protein in blood. It is apparent that spongiform change, the characteristic lesion of scrapie and other prion diseases, is not responsible for the clinical signs in sheep, but may develop in an age dependent manner.

  3. Accumulation of pathological prion protein PrPSc in the skin of animals with experimental and natural scrapie.

    Directory of Open Access Journals (Sweden)

    Achim Thomzig

    2007-05-01

    Full Text Available Prion infectivity and its molecular marker, the pathological prion protein PrP(Sc, accumulate in the central nervous system and often also in lymphoid tissue of animals or humans affected by transmissible spongiform encephalopathies. Recently, PrP(Sc was found in tissues previously considered not to be invaded by prions (e.g., skeletal muscles. Here, we address the question of whether prions target the skin and show widespread PrP(Sc deposition in this organ in hamsters perorally or parenterally challenged with scrapie. In hamsters fed with scrapie, PrP(Sc was detected before the onset of symptoms, but the bulk of skin-associated PrP(Sc accumulated in the clinical phase. PrP(Sc was localized in nerve fibres within the skin but not in keratinocytes, and the deposition of PrP(Sc in skin showed no dependence from the route of infection and lymphotropic dissemination. The data indicated a neurally mediated centrifugal spread of prions to the skin. Furthermore, in a follow-up study, we examined sheep naturally infected with scrapie and detected PrP(Sc by Western blotting in skin samples from two out of five animals. Our findings point to the skin as a potential reservoir of prions, which should be further investigated in relation to disease transmission.

  4. Evidence for more cost-effective surveillance options for bovine spongiform encephalopathy (BSE) and scrapie in Great Britain.

    Science.gov (United States)

    Wall, Ben A; Arnold, Mark E; Radia, Devi; Gilbert, Will; Ortiz-Pelaez, Angel; Stärk, Katharina Dc; Van Klink, Ed; Guitian, Javier

    2017-08-10

    Transmissible spongiform encephalopathies (TSEs) are an important public health concern. Since the emergence of bovine spongiform encephalopathy (BSE) during the 1980s and its link with human Creutzfeldt-Jakob disease, active surveillance has been a key element of the European Union's TSE control strategy. Success of this strategy means that now, very few cases are detected compared with the number of animals tested. Refining surveillance strategies would enable resources to be redirected towards other public health priorities. Cost-effectiveness analysis was performed on several alternative strategies involving reducing the number of animals tested for BSE and scrapie in Great Britain and, for scrapie, varying the ratio of sheep sampled in the abattoir to fallen stock (which died on the farm). The most cost-effective strategy modelled for BSE involved reducing the proportion of fallen stock tested from 100% to 75%, producing a cost saving of ca GBP 700,000 per annum. If 50% of fallen stock were tested, a saving of ca GBP 1.4 million per annum could be achieved. However, these reductions are predicted to increase the period before surveillance can detect an outbreak. For scrapie, reducing the proportion of abattoir samples was the most cost-effective strategy modelled, with limited impact on surveillance effectiveness. This article is copyright of The Authors, 2017.

  5. Prion protein gene variability in Spanish goats. Inference through susceptibility to classical scrapie strains and pathogenic distribution of peripheral PrP(sc..

    Directory of Open Access Journals (Sweden)

    Cristina Acín

    Full Text Available Classical scrapie is a neurological disorder of the central nervous system (CNS characterized by the accumulation of an abnormal, partially protease resistant prion protein (PrP(sc in the CNS and in some peripheral tissues in domestic small ruminants. Whereas the pathological changes and genetic susceptibility of ovine scrapie are well known, caprine scrapie has been less well studied. We report here a pathological study of 13 scrapie-affected goats diagnosed in Spain during the last 9 years. We used immunohistochemical and biochemical techniques to discriminate between classical and atypical scrapie and bovine spongiform encephalopathy (BSE. All the animals displayed PrP(sc distribution patterns and western blot characteristics compatible with classical scrapie. In addition, we determined the complete open reading frame sequence of the PRNP in these scrapie-affected animals. The polymorphisms observed were compared with those of the herd mates (n = 665 and with the frequencies of healthy herds (n = 581 of native Spanish goats (Retinta, Pirenaica and Moncaina and other worldwide breeds reared in Spain (Saanen, Alpine and crossbreed. In total, sixteen polymorphic sites were identified, including the known amino acid substitutions at codons G37V, G127S, M137I, I142M, H143R, R151H, R154H, R211Q, Q222K, G232W, and P240S, and new polymorphisms at codons G74D, M112T, R139S, L141F and Q215R. In addition, the known 42, 138 and 179 silent mutations were detected, and one new one is reported at codon 122. The genetic differences observed in the population studied have been attributed to breed and most of the novel polymorphic codons show frequencies lower than 5%. This work provides the first basis of polymorphic distribution of PRNP in native and worldwide goat breeds reared in Spain.

  6. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on the risk of transmission of classical scrapie via in vivo derived embryo transfer in ovine animals

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    . Under natural exposure conditions, animals that are heterozygous or homozygous A136R154R171 display respectively a low or negligible risk of being infected. The genetic control of the susceptibility to classical scrapie is also likely to impact on the risk of transmitting the disease via embryo transfer......The risk of transmission of classical scrapie via the transfer of in vivo derived embryo in ovines was assessed, taking into account the scientific information made available since the last EFSA opinion on this topic (2010) (see http://www.efsa.europa.eu/en/efsajournal/pub/1429.htm). The potential...... impact of PrP genotype of the embryo and/or of the ram and donor ewe on this risk was also assessed. The new data made available over the last three years further reinforce the view that classical scrapie could be vertically transmitted in sheep. Since the possibility of such vertical transmission...

  7. Primary transmission of chronic wasting disease versus scrapie prions from small ruminants to transgenic mice expressing ovine or cervid prion protein.

    Science.gov (United States)

    Madsen-Bouterse, Sally A; Schneider, David A; Zhuang, Dongyue; Dassanayake, Rohana P; Balachandran, Aru; Mitchell, Gordon B; O'Rourke, Katherine I

    2016-09-01

    Development of mice expressing either ovine (Tg338) or cervid (TgElk) prion protein (PrP) have aided in characterization of scrapie and chronic wasting disease (CWD), respectively. Experimental inoculation of sheep with CWD prions has demonstrated the potential for interspecies transmission but, infection with CWD versus classical scrapie prions may be difficult to differentiate using validated diagnostic platforms. In this study, mouse bioassay in Tg338 and TgElk was utilized to evaluate transmission of CWD versus scrapie prions from small ruminants. Mice (≥5 per homogenate) were inoculated with brain homogenates from clinically affected sheep or goats with naturally acquired classical scrapie, white-tailed deer with naturally acquired CWD (WTD-CWD) or sheep with experimentally acquired CWD derived from elk (sheep-passaged-CWD). Survival time (time to clinical disease) and attack rates (brain accumulation of protease resistant PrP, PrPres) were determined. Inoculation with classical scrapie prions resulted in clinical disease and 100 % attack rates in Tg338, but no clinical disease at endpoint (>300 days post-inoculation, p.i.) and low attack rates (6.8 %) in TgElk. Inoculation with WTD-CWD prions yielded no clinical disease or brain PrPres accumulation in Tg338 at endpoint (>500 days p.i.), but rapid onset of clinical disease (~121 days p.i.) and 100 % attack rate in TgElk. Sheep-passaged-CWD resulted in transmission to both mouse lines with 100 % attack rates at endpoint in Tg338 and an attack rate of ~73 % in TgElk with some culled due to clinical disease. These primary transmission observations demonstrate the potential of bioassay in Tg338 and TgElk to help differentiate possible infection with CWD versus classical scrapie prions in sheep and goats.

  8. Evaluation of efficacy of prion reduction filters using blood from an endogenously infected 263K scrapie hamster model.

    Science.gov (United States)

    McLeod, Neil P; Nugent, Philip; Dixon, Douglas; Dennis, Mike; Cornwall, Mark; Mallinson, Gary; Watkins, Nicholas; Thomas, Stephen; Sutton, J Mark

    2015-10-01

    The P-Capt prion reduction filter (MacoPharma) removes prion infectivity in model systems. This independent evaluation assesses prion removal from endogenously infected animal blood, using CE-marked P-Capt filters, and replicates the proposed use of the filter within the UK Blood Services. Two units of blood, generated from 263K scrapie-infected hamsters, were processed using leukoreduction filters (LXT-quadruple, MacoPharma). Approximately 100 mL of the removed plasma was added back to the red blood cells (RBCs) and the blood was filtered through a P-Capt filter. Samples of unfiltered whole blood, the prion filter input (RBCs plus plasma and SAGM [RBCPS]), and prion-filtered leukoreduced blood (PFB) were injected intracranially into hamsters. Clinical symptoms were monitored for 500 ± 1 day, and brains were assessed for spongiosis and prion protein deposit. In Filtration Run 1, none of the 50 challenged animals were diagnosed with scrapie after inoculation with the RBCPS fraction, while two of 190 hamsters injected with PFB were infected. In Filtration Run 2, one of 49 animals injected with RBCPS and two of 193 hamsters injected with PFB were infected. Run 1 reduced the infectious dose (ID) by 1.467 log (>1.187 log and <0.280 log for leukoreduction and prion filtration, respectively). Run 2 reduced prion infectivity by 1.424 log (1.127 and 0.297 log, respectively). Residual infectivity was estimated at 0.212 ± 0.149 IDs/mL (Run 1) and 0.208 ± 0.147 IDs/mL (Run 2). Leukoreduction removed the majority of infectivity from 263K scrapie hamster blood. The P-Capt filter removed a proportion of the remaining infectivity, but residual infectivity was observed in two independent processes. © 2015 AABB.

  9. IMPY, a potential {beta}-amyloid imaging probe for detection of prion deposits in scrapie-infected mice

    Energy Technology Data Exchange (ETDEWEB)

    Song, P.-J. [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Bernard, Serge [IFR135, F-37000 Tours (France); INRA, UR1282, IASP, 37380 Nouzilly (France)], E-mail: bernard@tours.inra.fr; Sarradin, Pierre [INRA, UR1282, IASP, 37380 Nouzilly (France); Vergote, Jackie [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Barc, Celine [INRA, UR1282, IASP, 37380 Nouzilly (France); Chalon, Sylvie [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Kung, M.-P.; Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Guilloteau, Denis [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France)

    2008-02-15

    Introduction: A potential single-photon emission computed tomography imaging agent for labeling of A{beta} plaques of Alzheimer's disease, IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), would be effective in detection of prion amyloid deposits in transmissible spongiform encephalopathies (TSEs). Methods: In vitro autoradiographic studies were carried out with [{sup 125}I]IMPY on brain sections from scrapie-infected mice and age-matched controls. Competition study was performed to evaluate the prion deposit binding specificity with nonradioactive IMPY. Results: Binding of [{sup 125}I]IMPY was observed in infected brain sections, while on age-matched control brain sections, there was no or very low labeling. Prion deposit binding was confirmed by histoblots with prion protein-specific monoclonal antibody 2D6. In the presence of nonradioactive IMPY, the binding of [{sup 125}I]IMPY was significantly inhibited in all regions studied. Conclusions: These findings indicate that IMPY can detect the prion deposits in vitro in scrapie-infected mice. Labeled with {sup 123}I, this ligand may be useful to quantitate prion deposit burdens in TSEs by in vivo imaging.

  10. IMPY, a potential β-amyloid imaging probe for detection of prion deposits in scrapie-infected mice

    International Nuclear Information System (INIS)

    Song, P.-J.; Bernard, Serge; Sarradin, Pierre; Vergote, Jackie; Barc, Celine; Chalon, Sylvie; Kung, M.-P.; Kung, Hank F.; Guilloteau, Denis

    2008-01-01

    Introduction: A potential single-photon emission computed tomography imaging agent for labeling of Aβ plaques of Alzheimer's disease, IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), would be effective in detection of prion amyloid deposits in transmissible spongiform encephalopathies (TSEs). Methods: In vitro autoradiographic studies were carried out with [ 125 I]IMPY on brain sections from scrapie-infected mice and age-matched controls. Competition study was performed to evaluate the prion deposit binding specificity with nonradioactive IMPY. Results: Binding of [ 125 I]IMPY was observed in infected brain sections, while on age-matched control brain sections, there was no or very low labeling. Prion deposit binding was confirmed by histoblots with prion protein-specific monoclonal antibody 2D6. In the presence of nonradioactive IMPY, the binding of [ 125 I]IMPY was significantly inhibited in all regions studied. Conclusions: These findings indicate that IMPY can detect the prion deposits in vitro in scrapie-infected mice. Labeled with 123 I, this ligand may be useful to quantitate prion deposit burdens in TSEs by in vivo imaging

  11. Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds.

    Science.gov (United States)

    Goldmann, W; Marier, E; Stewart, P; Konold, T; Street, S; Langeveld, J; Windl, O; Ortiz-Pelaez, A

    2016-02-13

    Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes in 10 goat breeds and 52 herds to find goats with the resistant K222 allele. They report here the frequencies in 1236 tested animals of the resistance-associated K222 and several other alleles by breed and herd. Eight animals were found to be heterozygous QK222 goats (0.64 per cent genotype frequency, 95 per cent CI 0.28 to 1.27 per cent) but no homozygous KK222 goats were detected. The K222 allele was found in Saanen, Toggenburg and Anglo-Nubian goats. The fact that only a few goats with the K222 allele have been identified does not preclude the possibility to design and implement successful breeding programmes at national level. British Veterinary Association.

  12. No evidence for involvement of plasma proteins or blood-borne cells in amyloid plaque formation in scrapie-affected mice. An immunohistoperoxidase study

    NARCIS (Netherlands)

    Eikelenboom, P.; Scott, J. R.; McBride, P. A.; Rozemuller, J. M.; Bruce, M. E.; Fraser, H.

    1987-01-01

    The present study was designed to investigate blood-brain permeability and the possible involvement of plasma proteins and blood-borne cells in amyloid plaque formation in scrapie-affected mice. No abnormal extravasation of intravenously injected horseradish peroxidase (HRP) was found and with

  13. PrP protein is associated with follicular dendritic cells of spleens and lymph nodes in uninfected and scrapie-infected mice

    NARCIS (Netherlands)

    McBride, P. A.; Eikelenboom, P.; Kraal, G.; Fraser, H.; Bruce, M. E.

    1992-01-01

    Abnormal forms of a host protein, PrP, accumulate in the central nervous system in scrapie-affected animals. Here, PrP protein was detected immunocytochemically in tissue sections of spleen, lymph node, Peyer's patches, thymus, and pancreas from uninfected mice and from mice infected with a range of

  14. Sheep scrapie susceptibility-linked polymorphisms do not modulate the initial binding of cellular to disease-associated prion protein prior to conversion

    NARCIS (Netherlands)

    Rigter, A.; Bossers, A.

    2005-01-01

    Conversion of the host-encoded protease-sensitive cellular prion protein (PrPC) into the scrapie-associated protease-resistant isoform (PrPSc) of prion protein (PrP) is the central event in transmissible spongiform encephalopathies or prion diseases. Differences in transmissibility and

  15. Primary transmission of chronic wasting disease versus scrapie prions from small ruminants to transgenic mice expressing ovine and cervid prion protein

    Science.gov (United States)

    Identifying transmissible spongiform encephalopathy (TSE) reservoirs that could lead to disease re-emergence is imperative to U.S. scrapie eradication efforts. Transgenic mice expressing the cervid (TgElk) or ovine (Tg338) prion protein have aided characterization of chronic wasting disease (CWD) an...

  16. Co-existence of scrapie prion protein types 1 and 2 in sporadic Creutzfeldt-Jakob disease: its effect on the phenotype and prion-type characteristics

    NARCIS (Netherlands)

    Cali, I.; Castellani, R.; Alshekhlee, A.; Cohen, Y.; Blevins, J.; Yuan, J.; Langeveld, J.P.M.; Parchi, P.; Safar, J.G.; Zou, W.Q.; Gambetti, P.

    2009-01-01

    Five phenotypically distinct subtypes have been identified in sporadic Creutzfeldt-Jakob disease (sCJD), based on the methionine/valine polymorphic genotype of codon 129 of the prion protein (PrP) gene and the presence of either one of the two protease K-resistant scrapie prion protein (PrPSc) types

  17. Genetic profile of scrapie codons 146, 211 and 222 in the PRNP gene locus in three breeds of dairy goats.

    Science.gov (United States)

    Vouraki, Sotiria; Gelasakis, Athanasios I; Alexandri, Panoraia; Boukouvala, Evridiki; Ekateriniadou, Loukia V; Banos, Georgios; Arsenos, Georgios

    2018-01-01

    Polymorphisms at PRNP gene locus have been associated with resistance against classical scrapie in goats. Genetic selection on this gene within appropriate breeding programs may contribute to the control of the disease. The present study characterized the genetic profile of codons 146, 211 and 222 in three dairy goat breeds in Greece. A total of 766 dairy goats from seven farms were used. Animals belonged to two indigenous Greek, Eghoria (n = 264) and Skopelos (n = 287) and a foreign breed, Damascus (n = 215). Genomic DNA was extracted from blood samples from individual animals. Polymorphisms were detected in these codons using Real-Time PCR analysis and four different Custom TaqMan® SNP Genotyping Assays. Genotypic, allelic and haplotypic frequencies were calculated based on individual animal genotypes. Chi-square tests were used to examine Hardy-Weinberg equilibrium state and compare genotypic distribution across breeds. Genetic distances among the three breeds, and between these and 30 breeds reared in other countries were estimated based on haplotypic frequencies using fixation index FST with Arlequin v3.1 software; a Neighbor-Joining tree was created using PHYLIP package v3.695. Level of statistical significance was set at P = 0.01. All scrapie resistance-associated alleles (146S, 146D, 211Q and 222K) were detected in the studied population. Significant frequency differences were observed between the indigenous Greek and Damascus breeds. Alleles 222K and 146S had the highest frequency in the two indigenous and the Damascus breed, respectively (ca. 6.0%). The studied breeds shared similar haplotypic frequencies with most South Italian and Turkish breeds but differed significantly from North-Western European, Far East and some USA goat breeds. Results suggest there is adequate variation in the PRNP gene locus to support breeding programs for enhanced scrapie resistance in goats reared in Greece. Genetic comparisons among goat breeds indicate that separate

  18. RECTAL BIOPSY IN SHEEP AND GOATS FOR MONITORING AND ANTE-MORTEM DIAGNOSIS OF SCRAPIE: NUMBER OF LYMPHOID FOLLICLES IN TWO CONSECUTIVE COLLECTIONS

    Directory of Open Access Journals (Sweden)

    Helen Caroline Raksa

    2016-07-01

    O acúmulo da PrPSc em tecidos linfoides levou ao desenvolvimento de procedimentos de biopsia para o diagnóstico ante mortem da scrapie em ovinos, utilizando tecidos acessíveis como a tonsila(5 e terceira pálpebra(6, e a técnica de imuno-histoquímica (IHQ. Por outro lado, a grande área de folículos linfoides presente no reto de ovinos(7 tornou a biopsia retal uma possibilidade de diagnóstico ante mortem da scrapie. Amostras da mucosa retal têm sido colhidas e analisadas por meio de provas de IHQ para avaliar a presença de PrPSc no tecido linfoide associado à mucosa retoanal (RAMALT, do inglês Recto-Anal Mucosa Associated Lymphoid Tissue(8,9. No Brasil, o primeiro relato de scrapie foi em 1978, em um ovino Hampshire Down, importado da Inglaterra(10. Segundo a OIE, de 2008 a 2014 foram sacrificados 41 animais no país, em surtos de scrapie(11. Desde 2008, o diagnóstico de scrapie é realizado por meio da técnica de IHQ a partir de amostras do SNC e tecidos linfoides(12. Porém, no caso de tecidos linfoides associados à mucosa retal, pode haver necessidade de novas colheitas em curtos intervalos de tempo devido à escassez de tecido para o diagnóstico da doença que, segundo Leal et al.(13, deve ser de no mínimo três folículos linfoides (FL por amostra. Visando ao reconhecimento de boas técnicas para o monitoramento e o diagnóstico ante mortem da scrapie, o presente estudo teve por objetivo avaliar a quantidade de tecido linfoide associado à mucosa retal obtido pela técnica de biopsia retal e com vistas à avaliação imuno-histoquímica, bem como a possibilidade de se realizarem dois procedimentos de biopsia consecutivos, em diferentes intervalos de tempo, em ovinos e caprinos.

  19. Substitutions of PrP N-terminal histidine residues modulate scrapie disease pathogenesis and incubation time in transgenic mice.

    Science.gov (United States)

    Eigenbrod, Sabina; Frick, Petra; Bertsch, Uwe; Mitteregger-Kretzschmar, Gerda; Mielke, Janina; Maringer, Marko; Piening, Niklas; Hepp, Alexander; Daude, Nathalie; Windl, Otto; Levin, Johannes; Giese, Armin; Sakthivelu, Vignesh; Tatzelt, Jörg; Kretzschmar, Hans; Westaway, David

    2017-01-01

    Prion diseases have been linked to impaired copper homeostasis and copper induced-oxidative damage to the brain. Divalent metal ions, such as Cu2+ and Zn2+, bind to cellular prion protein (PrPC) at octapeptide repeat (OR) and non-OR sites within the N-terminal half of the protein but information on the impact of such binding on conversion to the misfolded isoform often derives from studies using either OR and non-OR peptides or bacterially-expressed recombinant PrP. Here we created new transgenic mouse lines expressing PrP with disrupted copper binding sites within all four histidine-containing OR's (sites 1-4, H60G, H68G, H76G, H84G, "TetraH>G" allele) or at site 5 (composed of residues His-95 and His-110; "H95G" allele) and monitored the formation of misfolded PrP in vivo. Novel transgenic mice expressing PrP(TetraH>G) at levels comparable to wild-type (wt) controls were susceptible to mouse-adapted scrapie strain RML but showed significantly prolonged incubation times. In contrast, amino acid replacement at residue 95 accelerated disease progression in corresponding PrP(H95G) mice. Neuropathological lesions in terminally ill transgenic mice were similar to scrapie-infected wt controls, but less severe. The pattern of PrPSc deposition, however, was not synaptic as seen in wt animals, but instead dense globular plaque-like accumulations of PrPSc in TgPrP(TetraH>G) mice and diffuse PrPSc deposition in (TgPrP(H95G) mice), were observed throughout all brain sections. We conclude that OR and site 5 histidine substitutions have divergent phenotypic impacts and that cis interactions between the OR region and the site 5 region modulate pathogenic outcomes by affecting the PrP globular domain.

  20. PrP expression, PrPSc accumulation and innervation of splenic compartments in sheep experimentally infected with scrapie.

    Directory of Open Access Journals (Sweden)

    Randi Sørby

    Full Text Available BACKGROUND: In prion disease, the peripheral expression of PrP(C is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc accumulation, localisation of nerve fibres and PrP(C expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep. METHODOLOGY/PRINCIPAL FINDINGS: Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrP(C and PrP(Sc in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrP(Sc in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrP(Sc and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrP(Sc and nerves. Some nerve fibres were observed to accompany blood vessels into the PrP(Sc-laden germinal centres. However, the close association between nerves and PrP(Sc was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres. CONCLUSIONS/SIGNIFICANCE: The findings suggest that the degree of PrP(Sc accumulation does not depend on the expression level of PrP(C. Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrP(Sc.

  1. A Bayesian zero-truncated approach for analysing capture-recapture count data from classical scrapie surveillance in France.

    Science.gov (United States)

    Vergne, Timothée; Calavas, Didier; Cazeau, Géraldine; Durand, Benoît; Dufour, Barbara; Grosbois, Vladimir

    2012-06-01

    Capture-recapture (CR) methods are used to study populations that are monitored with imperfect observation processes. They have recently been applied to the monitoring of animal diseases to evaluate the number of infected units that remain undetected by the surveillance system. This paper proposes three bayesian models to estimate the total number of scrapie-infected holdings in France from CR count data obtained from the French classical scrapie surveillance programme. We fitted two zero-truncated Poisson (ZTP) models (with and without holding size as a covariate) and a zero-truncated negative binomial (ZTNB) model to the 2006 national surveillance count dataset. We detected a large amount of heterogeneity in the count data, making the use of the simple ZTP model inappropriate. However, including holding size as a covariate did not bring any significant improvement over the simple ZTP model. The ZTNB model proved to be the best model, giving an estimation of 535 (CI(95%) 401-796) infected and detectable sheep holdings in 2006, although only 141 were effectively detected, resulting in a holding-level prevalence of 4.4‰ (CI(95%) 3.2-6.3) and a sensitivity of holding-level surveillance of 26% (CI(95%) 18-35). The main limitation of the present study was the small amount of data collected during the surveillance programme. It was therefore not possible to build complex models that would allow depicting more accurately the epidemiological and detection processes that generate the surveillance data. We discuss the perspectives of capture-recapture count models in the context of animal disease surveillance. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. A "shotgun" method for tracing the birth locations of sheep from flock tags, applied to scrapie surveillance in Great Britain.

    Science.gov (United States)

    Birch, Colin P D; Del Rio Vilas, Victor J; Chikukwa, Ambrose C

    2010-09-01

    Movement records are often used to identify animal sample provenance by retracing the movements of individuals. Here we present an alternative method, which uses the same identity tags and movement records as are used to retrace movements, but ignores individual movement paths. The first step uses a simple query to identify the most likely birth holding for every identity tag included in a database recording departures from agricultural holdings. The second step rejects a proportion of the birth holding locations to leave a list of birth holding locations that are relatively reliable. The method was used to trace the birth locations of sheep sampled for scrapie in abattoirs, or on farm as fallen stock. Over 82% of the sheep sampled in the fallen stock survey died at the holding of birth. This lack of movement may be an important constraint on scrapie transmission. These static sheep provided relatively reliable birth locations, which were used to define criteria for selecting reliable traces. The criteria rejected 16.8% of fallen stock traces and 11.9% of abattoir survey traces. Two tests provided estimates that selection reduced error in fallen stock traces from 11.3% to 3.2%, and in abattoir survey traces from 8.1% to 1.8%. This method generated 14,591 accepted traces of fallen stock from samples taken during 2002-2005 and 83,136 accepted traces from abattoir samples. The absence or ambiguity of flock tag records at the time of slaughter prevented the tracing of 16-24% of abattoir samples during 2002-2004, although flock tag records improved in 2005. The use of internal scoring to generate and evaluate results from the database query, and the confirmation of results by comparison with other database fields, are analogous to methods used in web search engines. Such methods may have wide application in tracing samples and in adding value to biological datasets. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

  3. Accumulation and aberrant composition of cholesteryl esters in Scrapie-infected N2a cells and C57BL/6 mouse brains

    Directory of Open Access Journals (Sweden)

    Di Bari Michele A

    2011-08-01

    Full Text Available Abstract Objective Cholesterol changes have been described in prion-cell models and in experimental rodent scrapie; yet, the pattern of this association is still controversial. Methods To shed light on the matter, we analysed and compared cholesterol variations in ScN2a cells and in brains of Scrapie-infected C57Bl/6 mice, using two different methods: a fluorimetric-enzymatic cholesterol assay, and high performance liquid chromatography-mass spectroscopy (HPLC-MS. Results Compared to uninfected controls, similar cholesterol metabolism anomalies were observed in infected cells and brains by both methods; however, only HPLC-MS revealed statistically significant cholesterol variations, particularly in the cholesteryl esters (CE fraction. HPLC-MS analyses also revealed different fatty acid composition of the CE fraction in cells and brains. In N2a cells, their profile reflected that of serum, while in normal brains cholesteryl-linoleate only was found at detectable levels. Following prion infection, most CE species were increased in the CE pool of ScN2a cells, whereas a conspicuous amount of cholesteryl-arachidonate only was found to contribute to the cerebral increase of CE. Of interest, oral pravastatin administration to Scrapie-infected mice, was associated with a significant reduction of cerebral free cholesterol (FC along with a concomitant further increase of the CE pool, which included increased amounts of both cholesteryl-linoleate and cholesteryl-arachidonate. Conclusion Although mechanistic studies are needed to establish the pathophysiological relevance of changes in cerebral CE concentrations, to the best of our knowledge this is the first report to provide evidence of increased cholesterol esterification in brains of prion-infected mice, untreated and treated with pravastatin.

  4. Prion seeding activities of mouse scrapie strains with divergent PrPSc protease sensitivities and amyloid plaque content using RT-QuIC and eQuIC.

    Directory of Open Access Journals (Sweden)

    Sarah Vascellari

    Full Text Available Different transmissible spongiform encephalopathy (TSE-associated forms of prion protein (e.g. PrP(Sc can vary markedly in ultrastructure and biochemical characteristics, but each is propagated in the host. PrP(Sc propagation involves conversion from its normal isoform, PrP(C, by a seeded or templated polymerization mechanism. Such a mechanism is also the basis of the RT-QuIC and eQuIC prion assays which use recombinant PrP (rPrP(Sen as a substrate. These ultrasensitive detection assays have been developed for TSE prions of several host species and sample tissues, but not for murine models which are central to TSE pathogenesis research. Here we have adapted RT-QuIC and eQuIC to various murine prions and evaluated how seeding activity depends on glycophosphatidylinositol (GPI anchoring and the abundance of amyloid plaques and protease-resistant PrP(Sc (PrP(Res. Scrapie brain dilutions up to 10(-8 and 10(-13 were detected by RT-QuIC and eQuIC, respectively. Comparisons of scrapie-affected wild-type mice and transgenic mice expressing GPI anchorless PrP showed that, although similar concentrations of seeding activity accumulated in brain, the heavily amyloid-laden anchorless mouse tissue seeded more rapid reactions. Next we compared seeding activities in the brains of mice with similar infectivity titers, but widely divergent PrP(Res levels. For this purpose we compared the 263K and 139A scrapie strains in transgenic mice expressing P101L PrP(C. Although the brains of 263K-affected mice had little immunoblot-detectable PrP(Res, RT-QuIC indicated that seeding activity was comparable to that associated with a high-PrP(Res strain, 139A. Thus, in this comparison, RT-QuIC seeding activity correlated more closely with infectivity than with PrP(Res levels. We also found that eQuIC, which incorporates a PrP(Sc immunoprecipitation step, detected seeding activity in plasma from wild-type and anchorless PrP transgenic mice inoculated with 22L, 79A and/or RML

  5. Na+/K+-ATPase is present in scrapie-associated fibrils, modulates PrP misfolding in vitro and links PrP function and dysfunction.

    Directory of Open Access Journals (Sweden)

    James F Graham

    Full Text Available Transmissible spongiform encephalopathies are characterised by widespread deposition of fibrillar and/or plaque-like forms of the prion protein. These aggregated forms are produced by misfolding of the normal prion protein, PrP(C, to the disease-associated form, PrP(Sc, through mechanisms that remain elusive but which require either direct or indirect interaction between PrP(C and PrP(Sc isoforms. A wealth of evidence implicates other non-PrP molecules as active participants in the misfolding process, to catalyse and direct the conformational conversion of PrP(C or to provide a scaffold ensuring correct alignment of PrP(C and PrP(Sc during conversion. Such molecules may be specific to different scrapie strains to facilitate differential prion protein misfolding. Since molecular cofactors may become integrated into the growing protein fibril during prion conversion, we have investigated the proteins contained in prion disease-specific deposits by shotgun proteomics of scrapie-associated fibrils (SAF from mice infected with 3 different strains of mouse-passaged scrapie. Concomitant use of negative control preparations allowed us to identify and discount proteins that are enriched non-specifically by the SAF isolation protocol. We found several proteins that co-purified specifically with SAF from infected brains but none of these were reproducibly and demonstrably specific for particular scrapie strains. The α-chain of Na(+/K(+-ATPase was common to SAF from all 3 strains and we tested the ability of this protein to modulate in vitro misfolding of recombinant PrP. Na(+/K(+-ATPase enhanced the efficiency of disease-specific conversion of recombinant PrP suggesting that it may act as a molecular cofactor. Consistent with previous results, the same protein inhibited fibrillisation kinetics of recombinant PrP. Since functional interactions between PrP(C and Na(+/K(+-ATPase have previously been reported in astrocytes, our data highlight this molecule as

  6. Effect of Polymorphisms at Codon 146 of the Goat PRNP Gene on Susceptibility to Challenge with Classical Scrapie by Different Routes.

    Science.gov (United States)

    Papasavva-Stylianou, Penelope; Simmons, Marion Mathieson; Ortiz-Pelaez, Angel; Windl, Otto; Spiropoulos, John; Georgiadou, Soteria

    2017-11-15

    This report presents the results of experimental challenges of goats with scrapie by both the intracerebral (i.c.) and oral routes, exploring the effects of polymorphisms at codon 146 of the goat PRNP gene on resistance to disease. The results of these studies illustrate that while goats of all genotypes can be infected by i.c. challenge, the survival distribution of the animals homozygous for asparagine at codon 146 was significantly shorter than those of animals of all other genotypes (chi-square value, 10.8; P = 0.001). In contrast, only those animals homozygous for asparagine at codon 146 (NN animals) succumbed to oral challenge. The results also indicate that any cases of infection in non-NN animals can be detected by the current confirmatory test (immunohistochemistry), although successful detection with the rapid enzyme-linked immunosorbent assay (ELISA) was more variable and dependent on the polymorphism. Together with data from previous studies of goats exposed to infection in the field, these data support the previously reported observations that polymorphisms at this codon have a profound effect on susceptibility to disease. It is concluded that only animals homozygous for asparagine at codon 146 succumb to scrapie under natural conditions. IMPORTANCE In goats, like in sheep, there are PRNP polymorphisms that are associated with susceptibility or resistance to scrapie. However, in contrast to the polymorphisms in sheep, they are more numerous in goats and may be restricted to certain breeds or geographical regions. Therefore, eradication programs must be specifically designed depending on the identification of suitable polymorphisms. An initial analysis of surveillance data suggested that such a polymorphism in Cypriot goats may lie in codon 146. In this study, we demonstrate experimentally that NN animals are highly susceptible after i.c. inoculation. The presence of a D or S residue prolonged incubation periods significantly, and prions were detected

  7. Methodological approach for substantiating disease freedom in a heterogeneous small population. Application to ovine scrapie, a disease with a strong genetic susceptibility.

    Science.gov (United States)

    Martinez, Marie-José; Durand, Benoit; Calavas, Didier; Ducrot, Christian

    2010-06-01

    Demonstrating disease freedom is becoming important in different fields including animal disease control. Most methods consider sampling only from a homogeneous population in which each animal has the same probability of becoming infected. In this paper, we propose a new methodology to calculate the probability of detecting the disease if it is present in a heterogeneous population of small size with potentially different risk groups, differences in risk being defined using relative risks. To calculate this probability, for each possible arrangement of the infected animals in the different groups, the probability that all the animals tested are test-negative given this arrangement is multiplied by the probability that this arrangement occurs. The probability formula is developed using the assumption of a perfect test and hypergeometric sampling for finite small size populations. The methodology is applied to scrapie, a disease affecting small ruminants and characterized in sheep by a strong genetic susceptibility defining different risk groups. It illustrates that the genotypes of the tested animals influence heavily the confidence level of detecting scrapie. The results present the statistical power for substantiating disease freedom in a small heterogeneous population as a function of the design prevalence, the structure of the sample tested, the structure of the herd and the associated relative risks. (c) 2010 Elsevier B.V. All rights reserved.

  8. In-situ spectroscopic investigation of transmissible spongiform encephalopathies: application of Fourier-transform infrared spectroscopy to a scrapie-hamster model

    Science.gov (United States)

    Kneipp, Janina; Lasch, Peter; Beekes, Michael; Naumann, Dieter

    2002-03-01

    Transmissible spongiform encephalopathies (TSE), such as BSE in cattle, scrapie in sheep and goats, and Creutzfeldt-Jakob disease in man are a group of fatal infectious diseases of the central nervous system that are far from being fully understood. Presuming the pathological changes to originate from small disease-specific compositional and structural modifications at the molecular level, Fourier-transform infrared (FTIR) spectroscopy can be used to achieve insight into biochemical parameters underlying pathogenesis. We have developed an FTIR microspectroscopy-based strategy which, as a combination of image reconstruction and multivariate pattern recognition methods, permitted the comparison of identical substructures in the cerebellum of healthy and TSE-infected Syrian hamsters in the terminal stage of the disease. Here we present FTIR data about the pathological changes of scrapie-infected and normal tissue of the gray matter structures stratum granulosum and stratum moleculare. IR spectroscopy was also applied to tissue pieces of the medulla oblongata of infected and control Syrian hamsters. Mapping data were analyzed with cluster analysis and imaging methods. We found variations in the spectra of the infected tissue, which are due to changes in carbohydrates, nucleic acids, phospholipids, and proteins.

  9. Aberrant ERK 1/2 complex activation and localization in scrapie-infected GT1-1 cells

    Directory of Open Access Journals (Sweden)

    Didonna Alessandro

    2010-08-01

    Full Text Available Abstract Background Fatal neurodegenerative disorders such as Creutzfeldt-Jakob and Gerstmann-Sträussler-Scheinker diseases in humans, scrapie and bovine spongiform encephalopathy in animals, are characterized by the accumulation in the brain of a pathological form of the prion protein (PrP denominated PrPSc. The latter derives from the host cellular form, PrPC, through a process whereby portions of its α-helical and coil structures are refolded into β-sheet structures. Results In this work, the widely known in vitro model of prion replication, hypothalamic GT1-1 cell line, was used to investigate cellular and molecular responses to prion infection. The MAP kinase cascade was dissected to assess the phosphorylation levels of src, MEK 1/2 and ERK 1/2 signaling molecules, both before and after prion infection. Our findings suggest that prion replication leads to a hyper-activation of this pathway. Biochemical analysis was complemented with immunofluorescence studies to map the localization of the ERK complex within the different cellular compartments. We showed how the ERK complex relocates in the cytosol upon prion infection. We correlated these findings with an impairment of cell growth in prion-infected GT1-1 cells as probed by MTT assay. Furthermore, given the persistent urgency in finding compounds able to cure prion infected cells, we tested the effects on the ERK cascade of two molecules known to block prion replication in vitro, quinacrine and Fab D18. We were able to show that while these two compounds possess similar effects in curing prion infection, they affect the MAP kinase cascade differently. Conclusions Taken together, our results help shed light on the molecular events involved in neurodegeneration and neuronal loss in prion infection and replication. In particular, the combination of chronic activation and aberrant localization of the ERK complex may lead to a lack of essential neuroprotective and survival factors

  10. Discovery of a novel, monocationic, small-molecule inhibitor of scrapie prion accumulation in cultured sheep microglia and Rov cells.

    Directory of Open Access Journals (Sweden)

    James B Stanton

    Full Text Available Prion diseases, including sheep scrapie, are neurodegenerative diseases with the fundamental pathogenesis involving conversion of normal cellular prion protein (PrP(C to disease-associated prion protein (PrP(Sc. Chemical inhibition of prion accumulation is widely investigated, often using rodent-adapted prion cell culture models. Using a PrP(Sc-specific ELISA we discovered a monocationic phenyl-furan-benzimidazole (DB772, which has previously demonstrated anti-pestiviral activity and represents a chemical category previously untested for anti-prion activity, that inhibited PrP(Sc accumulation and prion infectivity in primary sheep microglial cell cultures (PRNP 136VV/154RR/171QQ and Rov9 cultures (VRQ-ovinized RK13 cells. We investigated potential mechanisms of this anti-prion activity by evaluating PrP(C expression with quantitative RT-PCR and PrP ELISA, comparing the concentration-dependent anti-prion and anti-pestiviral effects of DB772, and determining the selectivity index. Results demonstrate at least an approximate two-log inhibition of PrP(Sc accumulation in the two cell systems and confirmed that the inhibition of PrP(Sc accumulation correlates with inhibition of prion infectivity. PRNP transcripts and total PrP protein concentrations within cell lysates were not decreased; thus, decreased PrP(C expression is not the mechanism of PrP(Sc inhibition. PrP(Sc accumulation was multiple logs more resistant than pestivirus to DB772, suggesting that the anti-PrP(Sc activity was independent of anti-pestivirus activity. The anti-PrP(Sc selectivity index in cell culture was approximately 4.6 in microglia and 5.5 in Rov9 cells. The results describe a new chemical category that inhibits ovine PrP(Sc accumulation in primary sheep microglia and Rov9 cells, and can be used for future studies into the treatment and mechanism of prion diseases.

  11. Chronic wasting disease and atypical forms of bovine spongiform encephalopathy and scrapie are not transmissible to mice expressing wild-type levels of human prion protein.

    Science.gov (United States)

    Wilson, Rona; Plinston, Chris; Hunter, Nora; Casalone, Cristina; Corona, Cristiano; Tagliavini, Fabrizio; Suardi, Silvia; Ruggerone, Margherita; Moda, Fabio; Graziano, Silvia; Sbriccoli, Marco; Cardone, Franco; Pocchiari, Maurizio; Ingrosso, Loredana; Baron, Thierry; Richt, Juergen; Andreoletti, Olivier; Simmons, Marion; Lockey, Richard; Manson, Jean C; Barron, Rona M

    2012-07-01

    The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several novel TSEs in sheep, cattle and deer have been described and the risk posed to humans by these agents is currently unknown. In this study, we inoculated two forms of atypical BSE (BASE and H-type BSE), a chronic wasting disease (CWD) isolate and seven isolates of atypical scrapie into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP). Upon challenge with these ruminant TSEs, gene-targeted Tg mice expressing human PrP did not show any signs of disease pathology. These data strongly suggest the presence of a substantial transmission barrier between these recently identified ruminant TSEs and humans.

  12. Identification of seven haplotypes of the caprine PrP gene at codons 127, 142, 154, 211, 222 and 240 in French Alpine and Saanen breeds and their association with classical scrapie.

    Science.gov (United States)

    Barillet, F; Mariat, D; Amigues, Y; Faugeras, R; Caillat, H; Moazami-Goudarzi, K; Rupp, R; Babilliot, J M; Lacroux, C; Lugan, S; Schelcher, F; Chartier, C; Corbière, F; Andréoletti, O; Perrin-Chauvineau, C

    2009-03-01

    In sheep, susceptibility to scrapie is mainly influenced by polymorphisms of the PrP gene. In goats, there are to date few data related to scrapie susceptibility association with PrP gene polymorphisms. In this study, we first investigated PrP gene polymorphisms of the French Alpine and Saanen breeds. Based on PrP gene open reading frame sequencing of artificial insemination bucks (n=404), six encoding mutations were identified at codons 127, 142, 154, 211, 222 and 240. However, only seven haplotypes could be detected: four (GIH(154)RQS, GIRQ(211)QS, GIRRK(222)S and GIRRQP(240)) derived from the wild-type allele (G(127)I(142)R(154)R(211)Q(222)S(240)) by a single-codon mutation, and two (S(127)IRRQP(240) and GM(142)RRQP(240)) by a double-codon mutation. A case-control study was then implemented in a highly affected Alpine and Saanen breed herd (90 cases/164 controls). Mutations at codon 142 (I/M), 154 (R/H), 211 (R/Q) and 222 (Q/K) were found to induce a significant degree of protection towards natural scrapie infection. Compared with the baseline homozygote wild-type genotype I(142)R(154)R(211)Q(222)/IRRQ goats, the odds of scrapie cases in IRQ(211)Q/IRRQ and IRRK(222)/IRRQ heterozygous animals were significantly lower [odds ratio (OR)=0.133, PFrench Alpine and Saanen breeds were low (0.5-18.5 %), which prevent us from assessing the influence of all the possible genotypes in natural exposure conditions.

  13. Creutzfeldt-Jakob disease a case report, with special attention to the electroencephalogram in this disorder and to its possible relationships to kuru, scrapie and «mad cow disease»

    Directory of Open Access Journals (Sweden)

    A.H. Chapman

    1993-06-01

    Full Text Available A case of Creutzfeldt-Jakob disease in a 58-year-old Brazillian cattle rancher and businessman is presented. The EEG was normal, which is consistent with the fact that it was made during the first half of his illness; in a later stage suppression of normal rhythms by slow moderate voltage waves would be expected. The resemblances of kuru, scrapie and "mad cow disease» to C-J disease are discussed. In each of these 4 illnesses the patient or affected animal (scrapie and «mad cow disease" (a has a widespread spongiform encephalopathy and consequent dementia, myoclonic epilepsy and cerebellar and corticospinal symptoms, (b Each illness is caused by a virus (or virus-like organism called a PrP or prion which is unusually resistant to heat and entirely resistant to ultraviolet light and x-rays, (c This causative agent can be transmitted to other mammals by intracerebral injection or, in the proved cases of 3 of them, by the oral route. Unresolved questions about C-J disease include the following: Are C-J disease, kuru, scrapie and "mad cow disease" essentially similar illnesses caused by the same virus or by subtle variants of it? What is the incubation period of C-J disease, and does its virus exist for long periods of time in some asymptomatic persons, some of whom may never become neurologically ill? How does this virus enter the bodies of most persons with C-J disease, and why does the clinical disease characteristically occur only in middle age?

  14. 78 FR 25943 - Changes to Scrapie Flock Certification Program

    Science.gov (United States)

    2013-05-03

    ... Health Programs, VS, APHIS, 4700 River Road Unit 39, Riverdale, MD 20737-1231; (301) 851-3497... systems of sheep and goats. It belongs to a group of diseases called transmissible spongiform... voluntary program within the broader NSEP. Producers who elect to join the SFCP agree to follow a set of...

  15. Genetic evidence for susceptibility and resistance against scrapie in ...

    Indian Academy of Sciences (India)

    Sharda Choudhary1 Neelam Gupta2 Geetika Jethra1 Digpal Singh Gour3. National Research Centre on Seed Spices, Tabiji, Ajmer 305 206, India; Indian council of Agricultural Research, PUSA, New Delhi 110 114, India; Escuela de Ingenieria en Alimentos, Biotecnologia y Agronomia, Instituto Tecnologico y de Estudios ...

  16. Gene expression profiling of mesenteric lymph nodes from sheep with natural scrapie

    NARCIS (Netherlands)

    Filali, H.; Martin-Burriel, I.; Harders, F.; Varona, L.; Hedman, C.; Mediano, D.R.; Monzón, M.; Bossers, A.; Badiola, J.J.

    2014-01-01

    Background - Prion diseases are characterized by the accumulation of the pathogenic PrPSc protein, mainly in the brain and the lymphoreticular system. Although prions multiply/accumulate in the lymph nodes without any detectable pathology, transcriptional changes in this tissue may reflect

  17. Detection of prion infectivity in fat tissues of scrapie-infected mice.

    Directory of Open Access Journals (Sweden)

    Brent Race

    2008-12-01

    Full Text Available Distribution of prion infectivity in organs and tissues is important in understanding prion disease pathogenesis and designing strategies to prevent prion infection in animals and humans. Transmission of prion disease from cattle to humans resulted in banning human consumption of ruminant nervous system and certain other tissues. In the present study, we surveyed tissue distribution of prion infectivity in mice with prion disease. We show for the first time detection of infectivity in white and brown fat. Since high amounts of ruminant fat are consumed by humans and also incorporated into animal feed, fat-containing tissues may pose a previously unappreciated hazard for spread of prion infection.

  18. Increased infectivity of anchorless mouse scrapie prions in transgenic mice overexpressing human prion protein.

    Science.gov (United States)

    Race, Brent; Phillips, Katie; Meade-White, Kimberly; Striebel, James; Chesebro, Bruce

    2015-06-01

    Prion protein (PrP) is found in all mammals, mostly as a glycoprotein anchored to the plasma membrane by a C-terminal glycosylphosphatidylinositol (GPI) linkage. Following prion infection, host protease-sensitive prion protein (PrPsen or PrPC) is converted into an abnormal, disease-associated, protease-resistant form (PrPres). Biochemical characteristics, such as the PrP amino acid sequence, and posttranslational modifications, such as glycosylation and GPI anchoring, can affect the transmissibility of prions as well as the biochemical properties of the PrPres generated. Previous in vivo studies on the effects of GPI anchoring on prion infectivity have not examined cross-species transmission. In this study, we tested the effect of lack of GPI anchoring on a species barrier model using mice expressing human PrP. In this model, anchorless 22L prions derived from tg44 mice were more infectious than 22L prions derived from C57BL/10 mice when tested in tg66 transgenic mice, which expressed wild-type anchored human PrP at 8- to 16-fold above normal. Thus, the lack of the GPI anchor on the PrPres from tg44 mice appeared to reduce the effect of the mouse-human PrP species barrier. In contrast, neither source of prions induced disease in tgRM transgenic mice, which expressed human PrP at 2- to 4-fold above normal. Prion protein (PrP) is found in all mammals, usually attached to cells by an anchor molecule called GPI. Following prion infection, PrP is converted into a disease-associated form (PrPres). While most prion diseases are species specific, this finding is not consistent, and species barriers differ in strength. The amino acid sequence of PrP varies among species, and this variability affects prion species barriers. However, other PrP modifications, including glycosylation and GPI anchoring, may also influence cross-species infectivity. We studied the effect of PrP GPI anchoring using a mouse-to-human species barrier model. Experiments showed that prions produced by mice expressing only anchorless PrP were more infectious than prions produced in mice expressing anchored PrP. Thus, the lack of the GPI anchor on prions reduced the effect of the mouse-human species barrier. Our results suggest that prion diseases that produce higher levels of anchorless PrP may pose an increased risk for cross-species infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. Correlation of cellular factors and differential scrapie prion permissiveness in ovine microglia

    Science.gov (United States)

    Prion diseases are fatal neurodegenerative disorders by which the native cellular prion protein (PrP-C) is misfolded into an accumulating, disease-associated isoform (PrP-D). To improve the understanding of prion pathogenesis and develop effective treatments, it is essential to elucidate factors con...

  20. Applicability of three anti-PrP peptide sera including staining of tonsils and brainstem of sheep with scrapie

    NARCIS (Netherlands)

    Garssen, G.J.; Keulen, van L.J.M.; Farquhar, C.F.; Smits, M.A.; Jacobs, J.G.; Bossers, A.; Meloen, R.H.; Langeveld, J.P.M.

    2000-01-01

    Three rabbit antibodies (R521, R505, R524) were produced, and raised to synthetic peptides corresponding to residues 94-105, 100-111, and 223-234, respectively, of the sheep prion protein (PrP). Epitope mapping analysis revealed the monospecific character of antisera R505 and R524. In addition to

  1. Alkaloidal glycosidase inhibitors (AGIs) as the cause of sporadic scrapie, and the potential treatment of both transmissible spongiform encephalopathies (TSEs) and human immunodeficiency virus (HIV) infection.

    Science.gov (United States)

    Dealler, S

    1994-02-01

    AGIs are produced by plants and microorgansims in the environment. They are absorbed from the gut, distributed throughout the body and are concentrated inside cells. AGIs alter the glycan chains of cellular glycoproteins (CGP) during their formation so that the same CGP produced by different clones of cells (and hence with different glycan chains) becomes structurally the same. Prion protein (PrP), a CGP, is rendered indestructable to cellular mechanisms (as PrPi) by the TSE infective process; it is suggested that AGIs could both cause and prevent this by altering the primary structure of PrP. HIV envelope protein, gp120, carries glycan chains that are decided by the clone of the cells by which it is produced. Each cellular clone would be expected to add a specific group of glycan chains, making the gp120 antigenically separate. As HIV infection progresses, infected clone numbers rise, the antigenic diversity of gp120 may rise as would antibody production, trying to keep pace. Antigenically stimulated CD4+ cells carrying HIV genes, increase HIV production with gp120 antigenically different from its stimulant. AGIs prevent the glycan diversity and may prevent the extension of HIV infection.

  2. Heparan sulfate proteoglycan is associated with amyloid plaques and neuroanatomically targeted PrP pathology throughout the incubation period of scrapie-infected mice

    NARCIS (Netherlands)

    McBride, P. A.; Wilson, M. I.; Eikelenboom, P.; Tunstall, A.; Bruce, M. E.

    1998-01-01

    Heparan sulfate proteoglycan (HSPG) has been found to be associated with amyloid deposits in a number of diseases including the cerebral amyloid plaques of Alzheimer's disease and the transmissible spongiform encephalopathies (TSEs). The role of HSPG in amyloid formation and the neurodegenerative

  3. Temporal resolution of misfolded prion protein transport, accumulation, glial activation, and neuronal death in the retinas of mice inoculated with scrapie

    Science.gov (United States)

    Currently, there is a lack of pathologic landmarks to describe the progression of prion disease in vivo. The goal of this work was to determine the temporal relationship between the transport of misfolded prion protein from the brain to the retina, the accumulation of PrPSc in the retina, the respon...

  4. Sensitive and specific detection of classical scrapie prions in the brain of goats by real-time quaking-induced conversion

    Science.gov (United States)

    The real-time quaking-induced conversion (RT-QuIC) is a rapid, specific, and sensitive prion seeding activity detection assay that uses recombinant prion protein (rPrPSen) to detect sub-infectious levels of the abnormal isoforms of the prion protein (PrPSc). Although RT-QuIC has been successfully us...

  5. High-Throughput Screening of Compounds for Anti-Transmissible Spongiform Encephalopathy Activity Using Cell-Culture and Cell-Free Models and Infected Animals

    National Research Council Canada - National Science Library

    Caughey, Byron

    2006-01-01

    .... One therapeutic approach is the inhibitors of PrPSc accumulation indeed many inhibitors of PrPSc accumulation in scrapie-infected cells also have anti-scrapie activity in rodents During This year...

  6. Prions and neuro degenerative diseases

    African Journals Online (AJOL)

    user

    2011-03-28

    Mar 28, 2011 ... scrapie (a fatal disease of sheep and goats), mad cow disease, Creutzfeldt-Jacob disease, fatal familial insomnia, kuru .... The scrapie agent is extremely resistant to heat ... movement, or the stress of handling, the animal may.

  7. Development of an Assay for the Detection of PrPres in Blood and Urine Based on PMCA Assay an ELISA Methods

    National Research Council Canada - National Science Library

    Rohwer, Robert G; Gregori, Luisa L

    2005-01-01

    .... The assay is been developed with test material from two animal models: the hamster infected with the 263K strain of scrapie and the sheep either naturally or experimentally infected with scrapie...

  8. Polymorphisms of the prion protein gene Arabi sheep breed in Iran

    African Journals Online (AJOL)

    Novin

    2011-11-09

    Nov 9, 2011 ... Key words: Prion protein gene (Prnp), polymorphisms, susceptibility, scrapie. INTRODUCTION. Scrapie is an invariably fatal .... consists of a DNA denaturation step (5 min at 95°C), followed by 30 amplification cycles ...

  9. 9 CFR 54.7 - Procedures for destruction of animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  10. Variation in the prion protein sequence in Dutch goat breeds

    NARCIS (Netherlands)

    Windig, J.J.; Hoving, R.A.H.; Priem, J.; Bossers, A.; Keulen, van L.J.M.; Langeveld, J.P.M.

    2016-01-01

    Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined

  11. Temporal resolution of PrPSc transport, PrPSc accumulation, activation of glia and neuronal death in retinas from C57Bl/6 mice inoculated with RML scrapie: Relevance to biomarkers of prion disease progression

    Science.gov (United States)

    Currently, there is a lack of pathologic landmarks to objectively evaluate the progression of prion disease in vivo. The goal of this work was to determine the temporal relationship between transport of misfolded prion protein to the retina from the brain, accumulation of PrPSc in the retina, the re...

  12. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the scrapie situation in the EU after 10 years of monitoring and control in sheep and goats

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    of breeding programmes for resistance to CS (BP-CS) in the dissemination of resistance into the general sheep population has been assessed for those countries for which the CS trend analysis has been performed. CS in sheep was reported in 17 MSs (average prevalence: 8.7 cases/10 000 tests), with heterogeneous...... the failure to improve the disease situation in the remaining seven MSs. At a national level, a reduction in CS seems to be linked to better-achieving BP-CSs. Control options applied to CS in sheep and goats indicate that a CS eradication policy that relies solely on the detection of infected flocks by post...... in sheep and goats are formulated....

  13. 9 CFR 54.3 - Animals eligible for indemnity payments.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Animals eligible for indemnity payments. 54.3 Section 54.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... SCRAPIE Scrapie Indemnification Program § 54.3 Animals eligible for indemnity payments. (a) Indemnity may...

  14. Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues

    DEFF Research Database (Denmark)

    Hvass, Henriette Cordes; Bergström, Ann-Louise; Ohm, Jakob

    2008-01-01

    spongiform encephalopathy (bovine brain), scrapie (ovine brain) and experimental scrapie in hamster and in mice. The antibodies were also used for PET-blotting in which PrPSc blotted from brain tissue sections onto a nitrocellulose membrane is visualized with antibodies after protease and denaturant...

  15. Department of Agriculture Semiannual Regulatory Agenda

    Science.gov (United States)

    2010-12-20

    ... Import Restrictions on Certain 0579-AC74 Live Fish 189 Scrapie in Sheep and Goats 0579-AC92 190 Plant..., Farming Experience as an Eligibility Requirement; 5201, Eligibility of Equine Farmers and Ranchers for... Phone: 301 734-8695 RIN: 0579-AC74 189. SCRAPIE IN SHEEP AND GOATS Legal Authority: 7 USC 8301 to 8317...

  16. 76 FR 39998 - Semiannual Regulatory Agenda, Spring 2011

    Science.gov (United States)

    2011-07-07

    ... Import Restrictions on Certain Live Fish. 14 Scrapie in Sheep and Goats 0579-AC92 15 Plant Pest... Land Sales Program Down Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement..., Phone: 301 734-8695. RIN: 0579-AC74 14. Scrapie in Sheep and Goats Legal Authority: 7 U.S.C. 8301 to...

  17. 77 FR 7890 - Semiannual Regulatory Agenda, Fall 2011

    Science.gov (United States)

    2012-02-13

    ... Encephalopathy; Importation of Bovines and Bovine Products. 181 Scrapie in Sheep and Goats 0579-AC92 182 Plant... Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement; and 5201, Eligibility of...: 301 734- 7837. RIN: 0579-AC68 181. Scrapie in Sheep and Goats Legal Authority: 7 U.S.C. 8301 to 8317...

  18. Genetic, histochemical and biochemical studies on goat TSE cases from Cyprus.

    Science.gov (United States)

    Niedermeyer, Susanne; Eiden, Martin; Toumazos, Pavlos; Papasavva-Stylianou, Penelope; Ioannou, Ioannis; Sklaviadis, Theodoros; Panagiotidis, Cynthia; Langeveld, Jan; Bossers, Alex; Kuczius, Thorsten; Kaatz, Martin; Groschup, Martin H; Fast, Christine

    2016-10-06

    Scrapie and bovine spongiform encephalopathy (BSE) are transmissible spongiform encephalopathies (TSE's) affecting sheep and goats. Susceptibility of goats to scrapie is influenced by polymorphisms of the prion protein gene (PRNP) of the host. Five polymorphisms are associated with reduced susceptibility to TSE's. In the study presented here caprine samples from a scrapie eradication program on Cyprus were genotyped and further characterized using BioRad TeSeE rapid test, histological, immunohistochemical and biochemical methods. In total 42 goats from 20 flocks were necropsied from which 25 goats showed a positive result in the rapid test, a spongiform encephalopathy and an accumulation of pathological prion protein (PrP Sc ) in the obex. PrP Sc deposits were demonstrated in the placenta, peripheral nervous and lymphoreticular system. Two animals showed PrP Sc -accumulations in peripheral tissues only. By discriminatory immunoblots a scrapie infection could be confirmed for all cases. Nevertheless, slight deviations in the glycosylation pattern might indicate the presence of different scrapie strains. Furthermore scrapie samples from goats in the current study demonstrated less long term resistance to proteinase K than ovine or caprine BSE control samples. Reduced scrapie susceptibility according to the PRNP genotype was demonstrated (Fishers Exact test, p goats with at least one polymorphism (p = 0.023) at the six codons examined and in particular for those with polymorphisms at codon 146 (p = 0.016). This work characterizes scrapie in goats having implications for breeding and surveillance strategies.

  19. Polymorphisms of the prion protein gene Arabi sheep breed in Iran ...

    African Journals Online (AJOL)

    Ovine scrapie is a neurodegenerative disease caused by polymorphisms of the prion protein gene (Prnp); especially the amino acid residue alterations at codons 136, 154, and 174, in sheep have been found to be associated with susceptibility to scrapie disease. We studied Prnp polymorphisms in local sheep of ...

  20. Fluorescent Immunoassay Development for PrPSc Detection and Antemortem Diagnosis of TSEs

    National Research Council Canada - National Science Library

    Carp, Richard I

    2005-01-01

    .... During the second year of this contract, we have focused on the development of an immunological method to isolate blood PrP from normal and scrapie-infected animals and the assembly of an optical...

  1. Bovine Spongiform Encephalopathy: Atypical Pros and Cons

    Science.gov (United States)

    Transmissible spongiform encephalopathies (TSEs) are fatal neurologic diseases that affect several mammalian species including human beings. Four animal TSE agents have been reported: scrapie of sheep and goats; chronic wasting disease (CWD) of deer, elk, and moose; transmissible mink encephalopath...

  2. 9 CFR 79.5 - Issuance of certificates.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND... the consignee. Certificates must indicate the flock of birth for any breeding sheep born after January...

  3. 9 CFR 71.20 - Approval of livestock facilities.

    Science.gov (United States)

    2010-01-01

    ... OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL... as 9 CFR 54.7(e)(2) if the disease of concern is scrapie and the quarantined animal gave birth or...

  4. High-Throughput Screening of Compounds for Anti-Transmissible Spongiform Encephalopathy Activity Using Cell-Culture and Cell-Free Models and Infected Animals

    Science.gov (United States)

    2008-07-01

    polyphenols were selected as PrPSc inhibitors against both strains of mouse scrapie in the SCDB assay. Tannin (tannic acid), the most potent inhibitor...of human prion disease is contingent on post-mortem (or biopsy) analysis of brain, despite a number of clinical and paraclinical laboratory features... analysis of the scrapie-associated protein PrP 27-30 in water by infrared spectroscopy. Biochemistry 30, 7672–7680 (1991). The first study revealing

  5. Polymorphisms at Amino Acid Residues 141 and 154 Influence Conformational Variation in Ovine PrP

    Science.gov (United States)

    Yang, Sujeong; Thackray, Alana M.; Hopkins, Lee; Monie, Tom P.; Burke, David F.; Bujdoso, Raymond

    2014-01-01

    Polymorphisms in ovine PrP at amino acid residues 141 and 154 are associated with susceptibility to ovine prion disease: Leu141Arg154 with classical scrapie and Phe141Arg154 and Leu141His154 with atypical scrapie. Classical scrapie is naturally transmissible between sheep, whereas this may not be the case with atypical scrapie. Critical amino acid residues will determine the range or stability of structural changes within the ovine prion protein or its functional interaction with potential cofactors, during conversion of PrPC to PrPSc in these different forms of scrapie disease. Here we computationally identified that regions of ovine PrP, including those near amino acid residues 141 and 154, displayed more conservation than expected based on local structural environment. Molecular dynamics simulations showed these conserved regions of ovine PrP displayed genotypic differences in conformational repertoire and amino acid side-chain interactions. Significantly, Leu141Arg154 PrP adopted an extended beta sheet arrangement in the N-terminal palindromic region more frequently than the Phe141Arg154 and Leu141His154 variants. We supported these computational observations experimentally using circular dichroism spectroscopy and immunobiochemical studies on ovine recombinant PrP. Collectively, our observations show amino acid residues 141 and 154 influence secondary structure and conformational change in ovine PrP that may correlate with different forms of scrapie. PMID:25126555

  6. Cytosolic PrP Can Participate in Prion-Mediated Toxicity

    Science.gov (United States)

    Thackray, Alana M.; Zhang, Chang; Arndt, Tina

    2014-01-01

    ABSTRACT Prion diseases are characterized by a conformational change in the normal host protein PrPC. While the majority of mature PrPC is tethered to the plasma membrane by a glycosylphosphatidylinositol anchor, topological variants of this protein can arise during its biosynthesis. Here we have generated Drosophila transgenic for cytosolic ovine PrP in order to investigate its toxic potential in flies in the absence or presence of exogenous ovine prions. While cytosolic ovine PrP expressed in Drosophila was predominantly detergent insoluble and showed resistance to low concentrations of proteinase K, it was not overtly detrimental to the flies. However, Drosophila transgenic for cytosolic PrP expression exposed to classical or atypical scrapie prion inocula showed a faster decrease in locomotor activity than similar flies exposed to scrapie-free material. The susceptibility to classical scrapie inocula could be assessed in Drosophila transgenic for panneuronal expression of cytosolic PrP, whereas susceptibility to atypical scrapie required ubiquitous PrP expression. Significantly, the toxic phenotype induced by ovine scrapie in cytosolic PrP transgenic Drosophila was transmissible to recipient PrP transgenic flies. These data show that while cytosolic PrP expression does not adversely affect Drosophila, this topological PrP variant can participate in the generation of transmissible scrapie-induced toxicity. These observations also show that PrP transgenic Drosophila are susceptible to classical and atypical scrapie prion strains and highlight the utility of this invertebrate host as a model of mammalian prion disease. IMPORTANCE During prion diseases, the host protein PrPC converts into an abnormal conformer, PrPSc, a process coupled to the generation of transmissible prions and neurotoxicity. While PrPC is principally a glycosylphosphatidylinositol-anchored membrane protein, the role of topological variants, such as cytosolic PrP, in prion-mediated toxicity and

  7. Generalized cerebral atrophy seen on MRI in a naturally exposed animal model for creutzfeldt-jakob disease

    Directory of Open Access Journals (Sweden)

    Dasanu Constantin A

    2010-11-01

    Full Text Available Abstract Background Magnetic resonance imaging has been used in the diagnosis of human prion diseases such as sCJD and vCJD, but patients are scanned only when clinical signs appear, often at the late stage of disease. This study attempts to answer the questions "Could MRI detect prion diseases before clinical symptoms appear?, and if so, with what confidence?" Methods Scrapie, the prion disease of sheep, was chosen for the study because sheep can fit into a human sized MRI scanner (and there were no large animal MRI scanners at the time of this study, and because the USDA had, at the time of the study, a sizeable sample of scrapie exposed sheep, which we were able to use for this purpose. 111 genetically susceptible sheep that were naturally exposed to scrapie were used in this study. Results Our MRI findings revealed no clear, consistent hyperintense or hypointense signal changes in the brain on either clinically affected or asymptomatic positive animals on any sequence. However, in all 37 PrPSc positive sheep (28 asymptomatic and 9 symptomatic, there was a greater ventricle to cerebrum area ratio on MRI compared to 74 PrPSc negative sheep from the scrapie exposed flock and 6 control sheep from certified scrapie free flocks as defined by immunohistochemistry (IHC. Conclusions Our findings indicate that MRI imaging can detect diffuse cerebral atrophy in asymptomatic and symptomatic sheep infected with scrapie. Nine of these 37 positive sheep, including 2 one-year old animals, were PrPSc positive only in lymph tissues but PrPSc negative in the brain. This suggests either 1 that the cerebral atrophy/neuronal loss is not directly related to the accumulation of PrPSc within the brain or 2 that the amount of PrPSc in the brain is below the detectable limits of the utilized immunohistochemistry assay. The significance of these findings remains to be confirmed in human subjects with CJD.

  8. Variation in the prion protein sequence in Dutch goat breeds.

    Science.gov (United States)

    Windig, J J; Hoving, R A H; Priem, J; Bossers, A; van Keulen, L J M; Langeveld, J P M

    2016-10-01

    Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined for six goat breeds in the Netherlands. Overall frequencies in Dutch goats were determined from 768 brain tissue samples in 2005, 766 in 2008 and 300 in 2012, derived from random sampling for the national scrapie surveillance without knowledge of the breed. Breed specific frequencies were determined in the winter 2013/2014 by sampling 300 breeding animals from the main breeders of the different breeds. Detailed analysis of the scrapie-resistant K222 haplotype was carried out in 2014 for 220 Dutch Toggenburger goats and in 2015 for 942 goats from the Saanen derived White Goat breed. Nine haplotypes were identified in the Dutch breeds. Frequencies for non-wild type haplotypes were generally low. Exception was the K222 haplotype in the Dutch Toggenburger (29%) and the S146 haplotype in the Nubian and Boer breeds (respectively 7 and 31%). The frequency of the K222 haplotype in the Toggenburger was higher than for any other breed reported in literature, while for the White Goat breed it was with 3.1% similar to frequencies of other Saanen or Saanen derived breeds. Further evidence was found for the existence of two M142 haplotypes, M142 /S240 and M142 /P240 . Breeds vary in haplotype frequencies but frequencies of resistant genotypes are generally low and consequently selective breeding for scrapie resistance can only be slow but will benefit from animals identified in this study. The unexpectedly high frequency of the K222 haplotype in the Dutch Toggenburger underlines the need for conservation of rare breeds in order to conserve genetic diversity rare or absent in other breeds. © 2016 Blackwell Verlag GmbH.

  9. Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2013

    DEFF Research Database (Denmark)

    Jensen, Tim Kåre

    of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Ani-mals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

  10. Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2014

    DEFF Research Database (Denmark)

    Jensen, Tim Kåre

    of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

  11. Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2012

    DEFF Research Database (Denmark)

    Jensen, Tim Kåre

    of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Ani-mals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

  12. Sheep-passaged bovine spongiform encephalopathy agent exhibits altered pathobiological properties in bovine-PrP transgenic mice

    NARCIS (Netherlands)

    Espinosa, J.C.; Andreoletti, O.; Castilla, J.; Herva, M.E.; Morales, M.; Alamillo, E.; San-Segundo, F.D.; Lacroux, C.; Lugan, S.; Salguero, F.J.; Langeveld, J.P.M.; Torres, J.M.

    2007-01-01

    Sheep can be experimentally infected with bovine spongiform encephalopathy (BSE), and the ensuing disease is similar to scrapie in terms of pathogenesis and clinical signs. BSE infection in sheep is an animal and human health concern. In this study, the transmission in BoPrP-Tg110 mice of prions

  13. Prions And Prion Diseases | Obi | African Journal of Clinical and ...

    African Journals Online (AJOL)

    Patients also may experience involuntary jerking movements called myoclonus, unusual sensation, insomnia, and confusion or memory problems. In the later stages of the disease, patients may have severe mental impairment (dementia) and may lose the ability to move or speak. Well known prion diseases include scrapie ...

  14. RESEARCH ARTICLE A cross-sectional study of PRNP gene in two ...

    Indian Academy of Sciences (India)

    Navya

    Prion protein gene (PRNP) analysis revealed that none of the scrapie cases carried the p.Gln222Lys ... genetic variation, with low presence of wild type goats and the lack of protective alleles. .... We analyzed 157 clinically healthy goats (94 males and 63 females) in more than 20 .... Results from a retrospective cohort study.

  15. A cross-sectional study of PRNP gene in two native Sicilian goat ...

    Indian Academy of Sciences (India)

    Sergio Migliore

    Prion protein gene (PRNP) analysis revealed that none of the scrapie cases carried the p. ... low presence of wild-type goats and the lack of protective alleles. ... Recent association studies showed that allelic vari- .... healthy goats (94 males and 63 females) in more than 20 ..... Results from a retrospective cohort study. Vet.

  16. Mapping of possible prion protein self interaction domains using peptide arrays

    NARCIS (Netherlands)

    Rigter, A.; Langeveld, J.P.M.; Timmers-Parohi, D.; Jacobs, J.G.; Moonen, P.L.J.M.; Bossers, A.

    2007-01-01

    Background The common event in transmissible spongiform encephalopathies (TSEs) or prion diseases is the conversion of host-encoded protease sensitive cellular prion protein (PrPC) into strain dependent isoforms of scrapie associated protease resistant isoform (PrPSc) of prion protein (PrP). These

  17. Prion Protein Self Interactions; a gateway to novel therapeutic strategies?

    NARCIS (Netherlands)

    Rigter, A.; Langeveld, J.P.M.; Zijderveld, van F.G.; Bossers, A.

    2010-01-01

    Transmissible spongiform encephalopathies (TSEs) or prion diseases are fatal neurodegenerative disorders and include among others Creutzfeldt–Jakob disease in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapie in sheep. The central event in disease development in TSEs is the

  18. Differential effects of divalent cations on elk prion protein fibril formation and stability

    Science.gov (United States)

    Misfolding of the normally folded prion protein of mammals (PrPC) into infectious fibrils causes a variety of different diseases, from scrapie in sheep to bovine spongiform encephalopathy in cattle to chronic wasting disease (CWD) in deer and elk. The misfolded form of PrPC, termed PrPSc, or in this...

  19. Effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion

    Directory of Open Access Journals (Sweden)

    Eiden Martin

    2011-02-01

    Full Text Available 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.

  20. Ovine leukocyte profiles do not associate with variation in the prion gene, but are breed-dependent

    Science.gov (United States)

    Prion genotype in sheep confer resistance to scrapie. In cattle, lymphocyte profile has been found to be associated with prion genotype. Therefore, the aim of this study was to determine if variations in the sheep prion gene were associated with leukocyte populations as measured by complete blood ce...

  1. Amidation and structure relaxation abolish the neurotoxicity of the prion peptide PrP106-126 in vivo and in vitro

    DEFF Research Database (Denmark)

    Bergstrøm, Linda Alice; Hvass, Henriette Cordes; Zsurger, N.

    2005-01-01

    One of the major pathological hallmarks of transmissible spongiform encephalopathies (TSEs) is the accumulation of a pathogenic (scrapie) isoform (PrPSc) of the cellular prion protein (PrPC) primarily in the central nervous system. The synthetic prion peptide PrP106-126 shares many characteristics...

  2. 76 FR 34033 - Notice of Request for Extension of Approval of an Information Collection; Interstate Movement of...

    Science.gov (United States)

    2011-06-10

    ...] Notice of Request for Extension of Approval of an Information Collection; Interstate Movement of Sheep... movement of sheep and goats to control the spread of scrapie. DATES: We will consider all comments that we... . FOR FURTHER INFORMATION CONTACT: For information on regulations for the interstate movement of sheep...

  3. PrPCWD lymphoid cell targets in early and advanced chronic wasting disease of mule deer

    NARCIS (Netherlands)

    Sigurdson, C.J.; Barillas-Mury, C.; Miller, M.W.; Oesch, B.; Keulen, van L.J.M.; Langeveld, J.P.M.; Hoover, E.A.

    2002-01-01

    Up to 15% of free-ranging mule deer in northeastern Colorado and southeastern Wyoming, USA, are afflicted with a prion disease, or transmissible spongiform encephalopathy (TSE), known as chronic wasting disease (CWD). CWD is similar to a subset of TSEs including scrapie and variant Creutzfeldt¿Jakob

  4. 75 FR 21729 - Semiannual Regulatory Agenda, Spring 2010

    Science.gov (United States)

    2010-04-26

    ... Goats 0579-AC92 17 Plant Pest Regulations; Update of General Provisions 0579-AC98 18 Bovine Spongiform... Sales Program Down Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement; 5201... AND GOATS Legal Authority: 7 USC 8301 to 8317 Abstract: This rulemaking would amend the scrapie...

  5. 75 FR 79709 - Semiannual Regulatory Agenda, Fall 2010

    Science.gov (United States)

    2010-12-20

    ... in Sheep and Goats 0579-AC92 190 Plant Pest Regulations; Update of General Provisions (Reg Plan Seq... Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement; 5201, Eligibility of Equine... Phone: 301 734-8695 RIN: 0579-AC74 189. SCRAPIE IN SHEEP AND GOATS Legal Authority: 7 USC 8301 to 8317...

  6. Pathogenesis of bovine spongiform encephalopathy in sheep

    NARCIS (Netherlands)

    Keulen, van L.J.M.; Vromans, M.E.W.; Dolstra, C.H.; Bossers, A.; Zijderveld, van F.G.

    2008-01-01

    The pathogenesis of bovine spongiform encephalopathy (BSE) in sheep was studied by immunohistochemical detection of scrapie-associated prion protein (PrPSc) in the gastrointestinal, lymphoid and neural tissues following oral inoculation with BSE brain homogenate. First accumulation of PrPSc was

  7. Encefalopatías Subagudas Espongiformes Transmisibles (ESET.

    Directory of Open Access Journals (Sweden)

    Gabriel Toro González

    2006-12-01

    Como está aceptado que el scrapie ha sido el punto de partida en la cadena de transmisión de lasmás impactantes ESET al comprobarse la transmisión oveja- bovino humano, es comprensible que siga vigente el interés por enriquecer el conocimiento sobre elverdadero origen y patogenia del prúrigo lumbar (4...

  8. Effect of Q211 and K222 PRNP polymorphic variants in the susceptibility of goats to oral infections with Goat Bovine Spongiform Encephalopathy

    NARCIS (Netherlands)

    Aguilar-Calvo, Patricia; Fast, C.; Tauscher, Kerstin; Espinosa, J.C.; Groschup, M.H.; Muhammad, Nadeem; Goldmann, W.; Langeveld, J.P.M.; Bossers, A.; Andreoletti, O.

    2015-01-01

    Background. The prion protein-encoding gene (PRNP) is one of the major determinants for scrapie occurrence in sheep and goats. However, its effect on bovine spongiform encephalopathy (BSE) transmission to goats is not clear.

    Methods. Goats harboring wild-type, R/Q211 or Q/K222 PRNP

  9. 9 CFR 79.3 - General restrictions.

    Science.gov (United States)

    2010-01-01

    ....3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... only if they are identified to their flock of birth.— (1) High-risk, scrapie-positive, or suspect... any animal born after 1-1-2002, the certificate must include the flock of birth and the flock of...

  10. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Scrapie disease is considered endemic in Sicily since 1997, following the administration of an infected vaccine. ... Istituto Zooprofilattico Sperimentale of Sicily, Adelmo Mirri, via Gino Marinuzzi 3, 90129 Palermo, Italy; Public Veterinary Service, ASP 9 Trapani, 91017 Pantelleria, Italy; The Roslin Institute, R(D)SVS University ...

  11. Repetitive immunization enhances the susceptibility of mice to peripherally administered prions.

    Directory of Open Access Journals (Sweden)

    Juliane Bremer

    Full Text Available The susceptibility of humans and animals to prion infections is determined by the virulence of the infectious agent, by genetic modifiers, and by hitherto unknown host and environmental risk factors. While little is known about the latter two, the activation state of the immune system was surmised to influence prion susceptibility. Here we administered prions to mice that were repeatedly immunized by two initial injections of CpG oligodeoxynucleotides followed by repeated injections of bovine serum albumin/alum. Immunization greatly reduced the required dosage of peripherally administered prion inoculum necessary to induce scrapie in 50% of mice. No difference in susceptibility was observed following intracerebral prion challenge. Due to its profound impact onto scrapie susceptibility, the host immune status may determine disease penetrance after low-dose prion exposure, including those that may give rise to iatrogenic and variant Creutzfeldt-Jakob disease.

  12. Prion remains infectious after passage through digestive system of American crows (Corvus brachyrhynchos.

    Directory of Open Access Journals (Sweden)

    Kurt C VerCauteren

    Full Text Available Avian scavengers, such as American crows (Corvus brachyrhynchos, have potential to translocate infectious agents (prions of transmissible spongiform encephalopathy (TSE diseases including chronic wasting disease, scrapie, and bovine spongiform encephalopathy. We inoculated mice with fecal extracts obtained from 20 American crows that were force-fed material infected with RML-strain scrapie prions. These mice all evinced severe neurological dysfunction 196-231 d postinoculation (x =198; 95% CI: 210-216 and tested positive for prion disease. Our results suggest a large proportion of crows that consume prion-positive tissue are capable of passing infectious prions in their feces (ˆp=1.0; 95% CI: 0.8-1.0. Therefore, this common, migratory North American scavenger could play a role in the geographic spread of TSE diseases.

  13. Prion diseases are efficiently transmitted by blood transfusion in sheep

    OpenAIRE

    Houston, F.; McCutcheon, S.; Goldmann, W.; Chong, A.; Foster, J.; Siso, S.; Gonzalez, L.; Jeffrey, M.; Hunter, N.

    2008-01-01

    The emergence of variant Creutzfeld-Jakob disease, following on from the bovine spongiform encephalopathy (BSE) epidemic, led to concerns about the potential risk of iatrogenic transmission of disease by blood transfusion and the introduction of costly control measures to protect blood supplies. We previously reported preliminary data demonstrating the transmission of BSE and natural scrapie by blood transfusion in sheep. The final results of this experiment, reported here, give unexpectedly ...

  14. Paradox of Genetic Diversity in the Case of Prionic Diseases in Sheep Breeds from Romania

    Directory of Open Access Journals (Sweden)

    Gheorghe Hrinca

    2016-05-01

    Full Text Available The main target of this debate is the revaluation of the biodiversity concept and especially of its significance in the animal husbandry field. The paper analyzes the genetic diversity at the determinant locus of scrapie (PrP in the sheep breeds from Romania: Palas Merino, Tsigai, Tsurcana, Botosani Karakul, Palas Meat Breed and Palas Milk Breed. The prionic genetic diversity (d has been quantified by means of informational energy (e. This study highlights the impact of increasing the genetic diversity from the PrP locus level on the health status of ovine species and especially on human food safety. The informational statistics processing shows that the resistance / susceptibility to scrapie is in relation to the degree of prionic genetic diversity. The limitation of genetic diversity by selecting the individuals possessing the ARR allele in both homozygous status and in combination with alleles ARQ, ARH AHQ confers to sheep herds certain levels of resistance to contamination with scrapie disease. Instead, promoting to reproduction also individuals possessing the VRQ allele in all possible genotypic combinations (including ARR allele increases genetic diversity but also has as effect increasing the susceptibility of sheep to prion disease onset. From the point of view of morbid phenomenon, the Botosani Karakul breed is clearly advantaged compared to all other indigenous sheep breeds from Romania. For methodological coherency in the interpretative context of this issue, the genetic diversity was analyzed in association with the heterozygosity degree of breeds and their Hardy-Weinberg genetic equilibrium at the PrP locus level. Finally, the paper refers to decisions that the improvers must take to achieve the genetic prophylaxis in the scrapie case taking into account the polymorphism degree of prion protein.

  15. Gene and protein patterns of potential prion-related markers in the central nervous system of clinical and preclinical infected sheep

    Science.gov (United States)

    2013-01-01

    The molecular pathogenic mechanisms of prion diseases are far from clear. Genomic analyses have revealed genetic biomarkers potentially involved in prion neuropathology in naturally scrapie-infected sheep, a good animal model of infectious prionopathies. However, these biomarkers must be validated in independent studies at different stages of the disease. The gene and protein expression profiles and protein distribution of six potential genetic biomarkers (i.e., CAPN6, COL1A2, COL3A1, GALA1, MT2A and MTNR1B) are presented here for both the early and terminal stages of scrapie in five different brain regions. Gene transcription changes were confirmed in the medulla oblongata, and the expression profiles were generally similar in other central nervous system regions. The changes were more substantial in clinical animals compared to preclinical animals. The expression of the CAPN6 protein increased in the spinal cord and cerebellum of the clinical and preclinical brains. The distribution of the GALA1 was identified in glial cells from the cerebellum of scrapie-infected animals, GALA1 protein expression was increased in clinical animals in the majority of regions, and the increase of MT2A was in agreement with previous reports. The downregulation of MTNR1B was especially marked in the Purkinje cells. Finally, although collagen genes were downregulated the protein immunostaining did not reveal significant changes between the scrapie-infected and control animals. In conclusion, this study of gene transcription and protein expression and distribution confirm CAPN6, GALA1, MTNR1B and MT2A as potential targets for further prion disease research. PMID:23497022

  16. The Structural Stability of Wild-type Horse Prion Protein - Molecular Dynamics Studies

    OpenAIRE

    Zhang, Jiapu

    2011-01-01

    Prion diseases {\\it (e.g. Creutzfeldt-Jakob disease (CJD), variant CJD (vCJD), Gerstmann-Str$\\ddot{\\text{a}}$ussler-Scheinker syndrome (GSS), Fatal Familial Insomnia (FFI) and Kuru in humans, scrapie in sheep, bovine spongiform encephalopathy (BSE or `mad-cow' disease) and chronic wasting disease (CWD) in cattles)} are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. However, by now there have not been some effective therapeutic approaches or med...

  17. Extraneural manifestations of prion infection in GPI-anchorless transgenic mice

    International Nuclear Information System (INIS)

    Lee, Andrew M.; Paulsson, Johan F.; Cruite, Justin; Andaya, Abegail A.; Trifilo, Matthew J.; Oldstone, Michael B.A.

    2011-01-01

    Earlier studies indicated that transgenic (tg) mice engineered to express prion protein (PrP) lacking the glycophosphatidylinositol (GPI -/- ) membrane anchor formed abnormal proteinase-resistant prion (PrPsc) amyloid deposits in their brains and hearts when infected with the RML strain of murine scrapie. In contrast, RML scrapie infection of normal mice with a GPI-anchored PrP did not deposit amyloid with PrPsc in the brain or the heart. Here we report that scrapie-infected GPI -/- PrP tg mice also deposit PrP and transmissible infectious material in the gut, kidneys, and islets of Langerhans. Similar to previously reported amyloid deposits in the brain and heart, amyloid deposits were found in the gut; however, no amyloid deposited in the islets. By high-resolution electron microscopy, we show PrP is located primarily in α cells and also β cells. Islets contain abundant insulin and there is no abnormality in glucose metabolism in infected GPI -/- PrP tg mice.

  18. Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock.

    Science.gov (United States)

    Harrington, Robert D; Herrmann-Hoesing, Lynn M; White, Stephen N; O'Rourke, Katherine I; Knowles, Donald P

    2009-01-22

    Selective breeding of sheep for arginine (R) at prion gene (PRNP) codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV) may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1) associated with the presence of OPPV provirus and 2) associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05). Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05). These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

  19. Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock

    Directory of Open Access Journals (Sweden)

    Herrmann-Hoesing Lynn M

    2009-01-01

    Full Text Available Abstract Selective breeding of sheep for arginine (R at prion gene (PRNP codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1 associated with the presence of OPPV provirus and 2 associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05. Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05. These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

  20. Prion structure investigated in situ, ex vivo, and in vitro by FTIR spectroscopy

    Science.gov (United States)

    Kneipp, Janina; Miller, Lisa M.; Spassov, Sashko; Sokolowski, Fabian; Lasch, Peter; Beekes, Michael; Naumann, Dieter

    2004-07-01

    Syrian hamster nervous tissue was investigated by FTIR microspectroscopy with conventional and synchrotron infrared light sources. Various tissue structures from the cerebellum and medulla oblongata of scrapie-infected and control hamsters were investigated at a spatial resolution of 50 μm. Single neurons in dorsal root ganglia of scrapie-infected hamsters were analyzed by raster scan mapping at 6 μm spatial resolution. These measurements enabled us to (i) scrutinize structural differences between infected and non-infected tissue and (ii) analyze for the first time the distribution of different protein structures in situ within single nerve cells. Single nerve cells exhibited areas of increased β-sheet content, which co-localized consistently with accumulations of the pathological prion protein (PrPSc). Spectral data were also obtained from purified, partly proteinase K digested PrPSc isolated from scrapie-infected nervous tissue of hamsters to elucidate similarities/dissimilarities between prion structure in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP90-232, whose in vitro transition from the predominantly a-helical isoform to β-sheet rich oligomeric structures was also investigated by FTIR spectroscopy.

  1. [Unconventional disease agents--a danger for humans and animals?].

    Science.gov (United States)

    Kaaden, O R

    1994-02-01

    The occurrence of bovine spongiform encephalopathy (BSE) in Great Britain in 1985/86, has focused again the public concern as well as scientific interest to the Scrapie disease of sheep and goat known more than 150 years. The agents of scrapie and BSE are characterized by unusual biological and physical-chemical properties, especially their high tenacity. Therefore, they are also designated "unconventional agents of viruses". Different theories have been proposed about their infectious characteristics--especially because of the apparent or real missing of an agent-specific nucleic acid--which are named Virinos, Prions or Nemavirus. The broad host range of Scrapie respective BSE, which includes domestic and wild ruminants, Suidae, Felidae, Mustelidae, small rodents, birds and non-primates, has created some concern since there might be an aetiological correlation between the transmissible spongiform encephalopathies of man (Creutzfeld-Jakob- and Gerstmann-Sträussler-Scheinker-Disease) and that of animals. Although at present neither epidemiological nor molecular biological evidence whatsoever was proved, the hypothesis cannot be completely disproved. The probability of infection through digestive tract seems to be rather unlikely but special precautions should be taken as far as production, investigation and application of human medicine drugs of animal origin. Furthermore, research about the aetiology of "unconventional agents" and pathogenesis of resulting diseases is necessary and should be intensified in Germany. Finally, only an early intra vitam-Diagnose and in vitro detection can avoid an further spread of this new category of diseases.

  2. In vitro prion protein conversion suggests risk of bighorn sheep (Ovis canadensis) to transmissible spongiform encephalopathies

    Science.gov (United States)

    Johnson, Christopher J.; Morawski, A.R.; Carlson, C.M.; Chang, H.

    2013-01-01

    Background: Transmissible spongiform encephalopathies (TSEs) affect both domestic sheep (scrapie) and captive and free-ranging cervids (chronic wasting disease; CWD). The geographical range of bighorn sheep (Ovis canadensis; BHS) overlaps with states or provinces that have contained scrapie-positive sheep or goats and areas with present epizootics of CWD in cervids. No TSEs have been documented in BHS, but the susceptibility of this species to TSEs remains unknown. Results: We acquired a library of BHS tissues and found no evidence of preexisting TSEs in these animals. The prion protein gene (Prnp) in all BHS in our library was identical to scrapie-susceptible domestic sheep (A136R 154Q171). Using an in vitro prion protein conversion assay, which has been previously used to assess TSE species barriers and, in our study appears to recollect known species barriers in mice, we assessed the potential transmissibility of TSEs to BHS. As expected based upon Prnp genotype, we observed BHS prion protein conversion by classical scrapie agent and evidence for a species barrier between transmissible mink encephalopathy (TME) and BHS. Interestingly, our data suggest that the species barrier of BHS to white-tailed deer or wapiti CWD agents is likely low. We also used protein misfolding cyclic amplification to confirm that CWD, but not TME, can template prion protein misfolding in A136R 154Q171genotype sheep. Conclusions: Our results indicate the in vitro conversion assay used in our study does mimic the species barrier of mice to the TSE agents that we tested. Based on Prnp genotype and results from conversion assays, BHS are likely to be susceptible to infection by classical scrapie. Despite mismatches in amino acids thought to modulate prion protein conversion, our data indicate that A136R154Q171 genotype sheep prion protein is misfolded by CWD agent, suggesting that these animals could be susceptible to CWD. Further investigation of TSE transmissibility to BHS, including

  3. Quantitative Risk Assessment of Bovine Spongiform Encephalopathy

    Science.gov (United States)

    Tsutsui, Toshiyuki; Kasuga, Fumiko

    Bovine spongiform encephalopathy (BSE) is a progressive neurological disease of cattle affecting the central nervous system and was first diagnosed in the United Kingdom (UK) in 1986 (Wells et al., 1987). This disease is one of the transmissible spongiform encephalopathy (TSE) which includes Creutzfeldt-Jakob disease (CJD) in humans and scrapie in sheep. The causative agent of TSE is considered to be an abnormal form of prion protein. However, the details of its pathogenic mechanism have not been fully identified. Scrapie, which causes neurological symptoms in sheep and goats, has existed in the UK for 200 years (Hoinville, 1996) and spread across the rest of the world in the 1900s (Detwiler & Baylis, 2003). There has been no report so far that scrapie can be transmitted to humans. Initially, BSE was also considered as a disease affecting only animals. However, a variant type of Creutzfeldt-Jakob disease (vCJD) was first reported in the UK, and exposure to a BSE agent was suspected (Collinge, Sidle, Meads, Ironside, & Hill, 1996). vCJD is clinically and pathologically different from the sporadic type of CJD, and age at clinical onset of vCJD is younger than sporadic type (Will et al., 1996). Since the UK government announced the possible association between BSE and vCJD in 1996, BSE has become a huge public health concern all over the world. Of particular concern about vCJD, the fatal disease in younger age, distorted consumer confidence in beef safety, and as a result reduced beef consumption has been seen in many BSE-affected countries.

  4. Protecting effect of PrP codons M142 and K222 in goats orally challenged with bovine spongiform encephalopathy prions.

    Science.gov (United States)

    Fast, C; Goldmann, W; Berthon, P; Tauscher, K; Andréoletti, O; Lantier, I; Rossignol, C; Bossers, A; Jacobs, J G; Hunter, N; Groschup, M H; Lantier, F; Langeveld, J P M

    2017-09-19

    Breeding towards genetic resistance to prion disease is effective in eliminating scrapie. In sheep, classical forms of scrapie have been eradicated almost completely in several countries by breeding programs using a prion protein (PrP) gene (PRNP) amino acid polymorphism. For goats, field and experimental studies have provided evidence for several amino acid polymorphisms that are associated with resistance to scrapie, but only limited data are available concerning the susceptibility of caprine PRNP genotypes to BSE. In this study, goat kids representing five PRNP genotypes based on three polymorphisms (M142, Q211 and K222 and the wild type I142, R211 and Q222) were orally challenged with bovine or goat BSE. Wild type goats were killed with clinical signs between 24-28 months post inoculation (mpi) to both challenges, and goats with genotype R/Q211 succumbed between 29-36 mpi. I/M142 goats developed clinical signs at 44-45 mpi and M/M142 goats remained healthy until euthanasia at 48 mpi. None of the Q/K222 goats showed definite clinical signs. Taken together the highest attack ratios were seen in wild type and R/Q211 goats, and the lowest in I/M142, M/M142 and Q/K222. In all genotype groups, one or more goats remained healthy within the incubation period in both challenges and without detectable PrP deposition in the tissues. Our data show that both the K222 and M142 polymorphisms lengthen the incubation period significantly compared to wild type animals, but only K222 was associated with a significant increase in resistance to BSE infection after oral exposure to both BSE sources.

  5. A new method for the characterization of strain-specific conformational stability of protease-sensitive and protease-resistant PrPSc.

    Directory of Open Access Journals (Sweden)

    Laura Pirisinu

    Full Text Available Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrP(Sc, a disease-associated isoform of the host-encoded cellular protein (PrP(C. Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrP(Sc. However, PrP(Sc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrP(Sc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrP(C and PrP(Sc by means of differential centrifugation. The conformational solubility and stability assay (CSSA was then developed by measuring PrP(Sc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl](1/2 values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl](1/2 values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M, followed by sheep scrapie (2.2 M and by MM2 sCJD (1.6 M. In order to test the ability of CSSA to characterise protease-sensitive PrP(Sc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrP(Sc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrP(Sc conformational stabilities of protease-resistant and protease-sensitive PrP(Sc and that it is a valuable tool

  6. Problematica del mal de las vacas locas y consecuencias

    OpenAIRE

    Fernandez Boj, Olga

    2003-01-01

    El presente trabajo se basa en el estudio sobre una enfermedad que causa una especie de locura en los bovinos denominada encefalitis espongiforme bovina, (EEB) y que también puede afectar al hombre con el nombre de Creutzfeldt-Jakob. La EEB (enfermedad espongiforme bovina) esta vinculada con el scrapie una enfermedad también prionica que se conoce desde hace 250 años y que afecta a las ovejas. Todo comenzó 1883 cuando una vaca tenia los mismos signos clínicos que las ovejas, per...

  7. Positive 14-3-3 and tau proteins in a sporadic Creutzfeldt-Jakob disease case and a brief perspective of prion diseases in Colombia.

    Science.gov (United States)

    Escandón-Vargas, Kevin; Zorrilla-Vaca, Andrés; Corral-Prado, Raúl Heli

    2016-02-24

    Prion diseases are rare neurodegenerative disorders occurring worldwide and affecting both humans and animals. Herein, we present the case of a patient diagnosed with definite sporadic Creutzfeldt-Jakob disease in Cali, Colombia. Besides neurological examination, 14-3-3 and tau proteins were valuable tools supporting the diagnosis. We also present a brief perspective of the prion diseases reported in Colombia to date. Although the incidence of prion diseases is unknown in Colombia, our literature review revealed that one case of scrapie in 1981 and 29 human sporadic cases of Creutzfeldt-Jakob disease have been documented and published in our country.

  8. A brief history of prions

    Science.gov (United States)

    Zabel, Mark D.; Reid, Crystal

    2015-01-01

    Proteins were described as distinct biological molecules and their significance in cellular processes was recognized as early as the 18th century. At the same time, Spanish shepherds observed a disease that compelled their Merino sheep to pathologically scrape against fences, a defining clinical sign that led to the disease being named scrapie. In the late 19th century, Robert Koch published his postulates for defining causative agents of disease. In the early 20th century, pathologists Creutzfeldt and Jakob described a neurodegenerative disease that would later be included with scrapie into a group of diseases known as transmissible spongiform encephalopathies (TSEs). Later that century, mounting evidence compelled a handful of scientists to betray the prevailing biological dogma governing pathogen replication that Watson and Crick so convincingly explained by cracking the genetic code just two decades earlier. Because TSEs seemed to defy these new rules, J.S. Griffith theorized mechanisms by which a pathogenic protein could encipher its own replication blueprint without a genetic code. Stanley Prusiner called this proteinaceous infectious pathogen a prion. Here we offer a concise account of the discovery of prions, the causative agent of TSEs, in the wider context of protein biochemistry and infectious disease. We highlight the discovery of prions in yeast and discuss the implication of prions as epigenomic carriers of biological and pathological information. We also consider expanding the prion hypothesis to include other proteins whose alternate isoforms confer new biological or pathological properties. PMID:26449713

  9. Prions: Beyond a Single Protein

    Science.gov (United States)

    Das, Alvin S.

    2016-01-01

    SUMMARY Since the term protein was first coined in 1838 and protein was discovered to be the essential component of fibrin and albumin, all cellular proteins were presumed to play beneficial roles in plants and mammals. However, in 1967, Griffith proposed that proteins could be infectious pathogens and postulated their involvement in scrapie, a universally fatal transmissible spongiform encephalopathy in goats and sheep. Nevertheless, this novel hypothesis had not been evidenced until 1982, when Prusiner and coworkers purified infectious particles from scrapie-infected hamster brains and demonstrated that they consisted of a specific protein that he called a “prion.” Unprecedentedly, the infectious prion pathogen is actually derived from its endogenous cellular form in the central nervous system. Unlike other infectious agents, such as bacteria, viruses, and fungi, prions do not contain genetic materials such as DNA or RNA. The unique traits and genetic information of prions are believed to be encoded within the conformational structure and posttranslational modifications of the proteins. Remarkably, prion-like behavior has been recently observed in other cellular proteins—not only in pathogenic roles but also serving physiological functions. The significance of these fascinating developments in prion biology is far beyond the scope of a single cellular protein and its related disease. PMID:27226089

  10. Bitemporal hypometabolism in Creutzfeldt-Jakob Disease measured by positron emission tomography with (F-18)2-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Friedland, R.P.; Budinger, T.F.; Prusiner, S.B.; Jagust, W.J.

    1984-01-01

    It is well established that Creutzfeldt-Jakob Disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54 year old male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen

  11. Distinct transmissibility features of TSE sources derived from ruminant prion diseases by the oral route in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein.

    Directory of Open Access Journals (Sweden)

    Jean-Noël Arsac

    Full Text Available Transmissible spongiform encephalopathies (TSEs are a group of fatal neurodegenerative diseases associated with a misfolded form of host-encoded prion protein (PrP. Some of them, such as classical bovine spongiform encephalopathy in cattle (BSE, transmissible mink encephalopathy (TME, kuru and variant Creutzfeldt-Jakob disease in humans, are acquired by the oral route exposure to infected tissues. We investigated the possible transmission by the oral route of a panel of strains derived from ruminant prion diseases in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein (A136R154Q171 under the control of the neuron-specific enolase promoter. Sources derived from Nor98, CH1641 or 87V scrapie sources, as well as sources derived from L-type BSE or cattle-passaged TME, failed to transmit by the oral route, whereas those derived from classical BSE and classical scrapie were successfully transmitted. Apart from a possible effect of passage history of the TSE agent in the inocula, this implied the occurrence of subtle molecular changes in the protease-resistant prion protein (PrPres following oral transmission that can raises concerns about our ability to correctly identify sheep that might be orally infected by the BSE agent in the field. Our results provide proof of principle that transgenic mouse models can be used to examine the transmissibility of TSE agents by the oral route, providing novel insights regarding the pathogenesis of prion diseases.

  12. Toward unfolding the prion misfolding mystery: protein free radical chemistry in transmissible spongiform encephalopathies

    International Nuclear Information System (INIS)

    Yang Chiming

    2003-01-01

    Owing to the high oxygen-respiration in the brain of mammals, oxidative damage to prion protein has been suggested to be an additional factor. A large body of intriguing features of scrapie and prion diseases have provided multiple lines of indirect chemistry evidence, suggesting that the infectious agents may be putative forms of sequence-specific prion radicals (SSPR) and/or their immediate precursors in the transmissible spongiform encephalopathies (TSE). Here a molecular mechanism corresponding to the self-replication of scrapie protein mediated by prion free-radical processes, consonant with 'protein-only' hypotheses is proposed. This new theory may not only aid our understanding of the occurrence of prions, but also provides new insight into the possible chemistry principles underlying the neutrodegenerative disorders. It is anticipated that future studies based on this suggestion and chemistry principles of genetic diseases may allow us to determine an effective approach to stop mad cow disease and its human version, new variant of Creutzfeldt-Jakob disease (v CJD)

  13. Physical, chemical and kinetic factors affecting prion infectivity.

    Science.gov (United States)

    Properzi, Francesca; Badhan, Anjna; Klier, Steffi; Schmidt, Christian; Klöhn, Peter C; Wadsworth, Jonathan D F; Clarke, Anthony R; Jackson, Graham S; Collinge, John

    2016-05-03

    The mouse-adapted scrapie prion strain RML is one of the most widely used in prion research. The introduction of a cell culture-based assay of RML prions, the scrapie cell assay (SCA) allows more rapid and precise prion titration. A semi-automated version of this assay (ASCA) was applied to explore a range of conditions that might influence the infectivity and properties of RML prions. These include resistance to freeze-thaw procedures; stability to endogenous proteases in brain homogenate despite prolonged exposure to varying temperatures; distribution of infective material between pellet and supernatant after centrifugation, the effect of reducing agents and the influence of detergent additives on the efficiency of infection. Apparent infectivity is increased significantly by interaction with cationic detergents. Importantly, we have also elucidated the relationship between the duration of exposure of cells to RML prions and the transmission of infection. We established that the infection process following contact of cells with RML prions is rapid and followed an exponential time course, implying a single rate-limiting process.

  14. Recombinant human prion protein inhibits prion propagation in vitro.

    Science.gov (United States)

    Yuan, Jue; Zhan, Yi-An; Abskharon, Romany; Xiao, Xiangzhu; Martinez, Manuel Camacho; Zhou, Xiaochen; Kneale, Geoff; Mikol, Jacqueline; Lehmann, Sylvain; Surewicz, Witold K; Castilla, Joaquín; Steyaert, Jan; Zhang, Shulin; Kong, Qingzhong; Petersen, Robert B; Wohlkonig, Alexandre; Zou, Wen-Quan

    2013-10-09

    Prion diseases are associated with the conformational conversion of the cellular prion protein (PrP(C)) into the pathological scrapie isoform (PrP(Sc)) in the brain. Both the in vivo and in vitro conversion of PrP(C) into PrP(Sc) is significantly inhibited by differences in amino acid sequence between the two molecules. Using protein misfolding cyclic amplification (PMCA), we now report that the recombinant full-length human PrP (rHuPrP23-231) (that is unglycosylated and lacks the glycophosphatidylinositol anchor) is a strong inhibitor of human prion propagation. Furthermore, rHuPrP23-231 also inhibits mouse prion propagation in a scrapie-infected mouse cell line. Notably, it binds to PrP(Sc), but not PrP(C), suggesting that the inhibitory effect of recombinant PrP results from blocking the interaction of brain PrP(C) with PrP(Sc). Our findings suggest a new avenue for treating prion diseases, in which a patient's own unglycosylated and anchorless PrP is used to inhibit PrP(Sc) propagation without inducing immune response side effects.

  15. Phosphatidylinositol-glycan-phospholipase D is involved in neurodegeneration in prion disease.

    Directory of Open Access Journals (Sweden)

    Jae-Kwang Jin

    Full Text Available PrPSc is formed from a normal glycosylphosphatidylinositol (GPI-anchored prion protein (PrPC by a posttranslational modification. Most GPI-anchored proteins have been shown to be cleaved by GPI phospholipases. Recently, GPI-phospholipase D (GPI-PLD was shown to be a strictly specific enzyme for GPI anchors. To investigate the involvement of GPI-PLD in the processes of neurodegeneration in prion diseases, we examined the mRNA and protein expression levels of GPI-PLD in the brains of a prion animal model (scrapie, and in both the brains and cerebrospinal fluids (CSF of sporadic and familial Creutzfeldt-Jakob disease (CJD patients. We found that compared with controls, the expression of GPI-PLD was dramatically down-regulated in the brains of scrapie-infected mice, especially in the caveolin-enriched membrane fractions. Interestingly, the observed decrease in GPI-PLD expression levels began at the same time that PrPSc began to accumulate in the infected brains and this decrease was also observed in both the brain and CSF of CJD patients; however, no differences in expression were observed in either the brains or CSF specimens from Alzheimer's disease patients. Taken together, these results suggest that the down-regulation of GPI-PLD protein may be involved in prion propagation in the brains of prion diseases.

  16. Bitemporal hypometabolism in Creutzfeldt-Jakob Disease measured by positron emission tomography with (F-18)2-fluorodeoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, R.P.; Budinger, T.F.; Prusiner, S.B.; Jagust, W.J.

    1984-01-01

    It is well established that Creutzfeldt-Jakob Disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54 year old male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen.

  17. Heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies

    Directory of Open Access Journals (Sweden)

    Konold Timm

    2011-12-01

    Full Text Available Abstract Background The function of the autonomic nervous system can be assessed by determining heart rate variability (HRV, which is impaired in some brainstem diseases in humans. Transmissible spongiform encephalopathies (TSEs in sheep are diseases characterised by accumulation of disease-associated prion protein in the brainstem, including nuclei of the parasympathetic nervous system. This study was undertaken to assess whether analysis of HRV can be used as an aid in the diagnosis of TSEs in clinically affected, naturally or experimentally infected sheep. Findings When HRV indices were compared between 41 clinical TSE cases (18 sheep infected with scrapie and 23 sheep infected with bovine spongiform encephalopathy, 11 control sheep and six sheep reported as scrapie suspects or dosed with BSE brain homogenate, which were not confirmed as TSE cases by postmortem tests, no significant differences were found between the groups. Median heart rate was significantly different but only when sheep were grouped by gender: it was higher in female TSE cases than in control sheep and higher in female than castrated male ovine classical BSE cases. Conclusions HRV analysis was not useful as a diagnostic aid for TSEs of sheep.

  18. Cleaning, disinfection and sterilization of surface prion contamination.

    Science.gov (United States)

    McDonnell, G; Dehen, C; Perrin, A; Thomas, V; Igel-Egalon, A; Burke, P A; Deslys, J P; Comoy, E

    2013-12-01

    Prion contamination is a risk during device reprocessing, being difficult to remove and inactivate. Little is known of the combined effects of cleaning, disinfection and sterilization during a typical reprocessing cycle in clinical practice. To investigate the combination of cleaning, disinfection and/or sterilization on reducing the risk of surface prion contamination. In vivo test methods were used to study the impact of cleaning alone and cleaning combined with thermal disinfection and high- or low-temperature sterilization processes. A standardized test method, based on contamination of stainless steel wires with high titres of scrapie-infected brain homogenates, was used to determine infectivity reduction. Traditional chemical methods of surface decontamination against prions were confirmed to be effective, but extended steam sterilization was more variable. Steam sterilization alone reduced the risk of prion contamination under normal or extended exposure conditions, but did show significant variation. Thermal disinfection had no impact in these studies. Cleaning with certain defined formulations in combination with steam sterilization can be an effective prion decontamination process, in particular with alkaline formulations. Low-temperature, gaseous hydrogen peroxide sterilization was also confirmed to reduce infectivity in the presence and absence of cleaning. Prion decontamination is affected by the full reprocessing cycle used on contaminated surfaces. The correct use of defined cleaning, disinfection and sterilization methods as tested in this report in the scrapie infectivity assay can provide a standard precaution against prion contamination. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  19. Aerosols transmit prions to immunocompetent and immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Johannes Haybaeck

    Full Text Available Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrP(C, efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrP(C selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrP(Sc and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories.

  20. Brain delivery of AAV9 expressing an anti-PrP monovalent antibody delays prion disease in mice.

    Science.gov (United States)

    Moda, Fabio; Vimercati, Chiara; Campagnani, Ilaria; Ruggerone, Margherita; Giaccone, Giorgio; Morbin, Michela; Zentilin, Lorena; Giacca, Mauro; Zucca, Ileana; Legname, Giuseppe; Tagliavini, Fabrizio

    2012-01-01

    Prion diseases are caused by a conformational modification of the cellular prion protein (PrP (C)) into disease-specific forms, termed PrP (Sc), that have the ability to interact with PrP (C) promoting its conversion to PrP (Sc). In vitro studies demonstrated that anti-PrP antibodies inhibit this process. In particular, the single chain variable fragment D18 antibody (scFvD18) showed high efficiency in curing chronically prion-infected cells. This molecule binds the PrP (C) region involved in the interaction with PrP (Sc) thus halting further prion formation. These findings prompted us to test the efficiency of scFvD18 in vivo. A recombinant Adeno-Associated Viral vector serotype 9 was used to deliver scFvD18 to the brain of mice that were subsequently infected by intraperitoneal route with the mouse-adapted scrapie strain RML. We found that the treatment was safe, prolonged the incubation time of scrapie-infected animals and decreased the burden of total proteinase-resistant PrP (Sc) in the brain, suggesting that scFvD18 interferes with prion replication in vivo. This approach is relevant for designing new therapeutic strategies for prion diseases and other disorders characterized by protein misfolding.

  1. Origin and implications of bovine spongiform encephalopathy.

    Science.gov (United States)

    Narang, H

    1996-04-01

    All spongiform encephalopathies in animals, including humans, are slow developing infectious diseases. The current working theory links the origin of bovine spongiform encephalopathy (BSE) to the feeding of cattle with meat and bone meal prepared from scrapie-infected sheep remains. Recycling of cattle meat and bones (MBM) essentially resulted in the selection of a single strain from the "wild type", a mixture of 20 strains. The BSE agent is easily transmitted through ingestion, with some evidence of vertical transmission. Paradoxically, cattle have selected a major new strain which appears to be more virulent than an unselected strain found in scrapie sheep. The same strain of BSE agent is implicated in the occurrence of spongiform encephalopathy in domestic cats, tiger, and some exotic species of ruminants in zoos. The properties of BSE and its spread into cattle are still disputed. Since our understanding of the disease and its transmissibility in humans must await observations that will be made over some years to come, it is important to keep a reasonable perspective and ensure that any speculative comment is consistent with fact. In risk assessment in such circumstances, it is tempting give too much credence to persuasive parallels when direct relevant information is not available. On the other hand, it would also not be wise to assume that the disease will die by itself and will have no effect on humans.

  2. Prion Protein Devoid of the Octapeptide Repeat Region Delays Bovine Spongiform Encephalopathy Pathogenesis in Mice.

    Science.gov (United States)

    Hara, Hideyuki; Miyata, Hironori; Das, Nandita Rani; Chida, Junji; Yoshimochi, Tatenobu; Uchiyama, Keiji; Watanabe, Hitomi; Kondoh, Gen; Yokoyama, Takashi; Sakaguchi, Suehiro

    2018-01-01

    Conformational conversion of the cellular isoform of prion protein, PrP C , into the abnormally folded, amyloidogenic isoform, PrP Sc , is a key pathogenic event in prion diseases, including Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy (BSE) in animals. We previously reported that the octapeptide repeat (OR) region could be dispensable for converting PrP C into PrP Sc after infection with RML prions. We demonstrated that mice transgenically expressing mouse PrP with deletion of the OR region on the PrP knockout background, designated Tg(PrPΔOR)/ Prnp 0 / 0 mice, did not show reduced susceptibility to RML scrapie prions, with abundant accumulation of PrP Sc ΔOR in their brains. We show here that Tg(PrPΔOR)/ Prnp 0 / 0 mice were highly resistant to BSE prions, developing the disease with markedly elongated incubation times after infection with BSE prions. The conversion of PrPΔOR into PrP Sc ΔOR was markedly delayed in their brains. These results suggest that the OR region may have a crucial role in the conversion of PrP C into PrP Sc after infection with BSE prions. However, Tg(PrPΔOR)/ Prnp 0 / 0 mice remained susceptible to RML and 22L scrapie prions, developing the disease without elongated incubation times after infection with RML and 22L prions. PrP Sc ΔOR accumulated only slightly less in the brains of RML- or 22L-infected Tg(PrPΔOR)/ Prnp 0 / 0 mice than PrP Sc in control wild-type mice. Taken together, these results indicate that the OR region of PrP C could play a differential role in the pathogenesis of BSE prions and RML or 22L scrapie prions. IMPORTANCE Structure-function relationship studies of PrP C conformational conversion into PrP Sc are worthwhile to understand the mechanism of the conversion of PrP C into PrP Sc We show here that, by inoculating Tg(PrPΔOR)/ Prnp 0 / 0 mice with the three different strains of RML, 22L, and BSE prions, the OR region could play a differential role in the conversion of

  3. Pruritus is a common feature in sheep infected with the BSE agent.

    Science.gov (United States)

    Konold, Timm; Bone, Gemma; Vidal-Diez, Alberto; Tortosa, Raul; Davis, Andrew; Dexter, Glenda; Hill, Peter; Jeffrey, Martin; Simmons, Marion M; Chaplin, Melanie J; Bellworthy, Susan J; Berthelin-Baker, Christine

    2008-04-29

    The variability in the clinical or pathological presentation of transmissible spongiform encephalopathies (TSEs) in sheep, such as scrapie and bovine spongiform encephalopathy (BSE), has been attributed to prion protein genotype, strain, breed, clinical duration, dose, route and type of inoculum and the age at infection. The study aimed to describe the clinical signs in sheep infected with the BSE agent throughout its clinical course to determine whether the clinical signs were as variable as described for classical scrapie in sheep. The clinical signs were compared to BSE-negative sheep to assess if disease-specific clinical markers exist. Forty-seven (34%) of 139 sheep, which comprised 123 challenged sheep and 16 undosed controls, were positive for BSE. Affected sheep belonged to five different breeds and three different genotypes (ARQ/ARQ, VRQ/VRQ and AHQ/AHQ). None of the controls or BSE exposed sheep with ARR alleles were positive. Pruritus was present in 41 (87%) BSE positive sheep; the remaining six were judged to be pre-clinically infected. Testing of the response to scratching along the dorsum of a sheep proved to be a good indicator of clinical disease with a test sensitivity of 85% and specificity of 98% and usually coincided with weight loss. Clinical signs that were displayed significantly earlier in BSE positive cases compared to negative cases were behavioural changes, pruritic behaviour, a positive scratch test, alopecia, skin lesions, teeth grinding, tremor, ataxia, loss of weight and loss of body condition. The frequency and severity of each specific clinical sign usually increased with the progression of disease over a period of 16-20 weeks. Our results suggest that BSE in sheep presents with relatively uniform clinical signs, with pruritus of increased severity and abnormalities in behaviour or movement as the disease progressed. Based on the studied sheep, these clinical features appear to be independent of breed, affected genotype, dose, route

  4. Epigenetic dominance of prion conformers.

    Directory of Open Access Journals (Sweden)

    Eri Saijo

    2013-10-01

    Full Text Available Although they share certain biological properties with nucleic acid based infectious agents, prions, the causative agents of invariably fatal, transmissible neurodegenerative disorders such as bovine spongiform encephalopathy, sheep scrapie, and human Creutzfeldt Jakob disease, propagate by conformational templating of host encoded proteins. Once thought to be unique to these diseases, this mechanism is now recognized as a ubiquitous means of information transfer in biological systems, including other protein misfolding disorders such as those causing Alzheimer's and Parkinson's diseases. To address the poorly understood mechanism by which host prion protein (PrP primary structures interact with distinct prion conformations to influence pathogenesis, we produced transgenic (Tg mice expressing different sheep scrapie susceptibility alleles, varying only at a single amino acid at PrP residue 136. Tg mice expressing ovine PrP with alanine (A at (OvPrP-A136 infected with SSBP/1 scrapie prions propagated a relatively stable (S prion conformation, which accumulated as punctate aggregates in the brain, and produced prolonged incubation times. In contrast, Tg mice expressing OvPrP with valine (V at 136 (OvPrP-V136 infected with the same prions developed disease rapidly, and the converted prion was comprised of an unstable (U, diffusely distributed conformer. Infected Tg mice co-expressing both alleles manifested properties consistent with the U conformer, suggesting a dominant effect resulting from exclusive conversion of OvPrP-V136 but not OvPrP-A136. Surprisingly, however, studies with monoclonal antibody (mAb PRC5, which discriminates OvPrP-A136 from OvPrP-V136, revealed substantial conversion of OvPrP-A136. Moreover, the resulting OvPrP-A136 prion acquired the characteristics of the U conformer. These results, substantiated by in vitro analyses, indicated that co-expression of OvPrP-V136 altered the conversion potential of OvPrP-A136 from the S to

  5. Inactivation of Prions and Amyloid Seeds with Hypochlorous Acid.

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    Andrew G Hughson

    2016-09-01

    Full Text Available Hypochlorous acid (HOCl is produced naturally by neutrophils and other cells to kill conventional microbes in vivo. Synthetic preparations containing HOCl can also be effective as microbial disinfectants. Here we have tested whether HOCl can also inactivate prions and other self-propagating protein amyloid seeds. Prions are deadly pathogens that are notoriously difficult to inactivate, and standard microbial disinfection protocols are often inadequate. Recommended treatments for prion decontamination include strongly basic (pH ≥~12 sodium hypochlorite bleach, ≥1 N sodium hydroxide, and/or prolonged autoclaving. These treatments are damaging and/or unsuitable for many clinical, agricultural and environmental applications. We have tested the anti-prion activity of a weakly acidic aqueous formulation of HOCl (BrioHOCl that poses no apparent hazard to either users or many surfaces. For example, BrioHOCl can be applied directly to skin and mucous membranes and has been aerosolized to treat entire rooms without apparent deleterious effects. Here, we demonstrate that immersion in BrioHOCl can inactivate not only a range of target microbes, including spores of Bacillus subtilis, but also prions in tissue suspensions and on stainless steel. Real-time quaking-induced conversion (RT-QuIC assays showed that BrioHOCl treatments eliminated all detectable prion seeding activity of human Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, cervine chronic wasting disease, sheep scrapie and hamster scrapie; these findings indicated reductions of ≥103- to 106-fold. Transgenic mouse bioassays showed that all detectable hamster-adapted scrapie infectivity in brain homogenates or on steel wires was eliminated, representing reductions of ≥~105.75-fold and >104-fold, respectively. Inactivation of RT-QuIC seeding activity correlated with free chlorine concentration and higher order aggregation or destruction of proteins generally, including prion

  6. Pruritus is a common feature in sheep infected with the BSE agent

    Directory of Open Access Journals (Sweden)

    Jeffrey Martin

    2008-04-01

    Full Text Available Abstract Background The variability in the clinical or pathological presentation of transmissible spongiform encephalopathies (TSEs in sheep, such as scrapie and bovine spongiform encephalopathy (BSE, has been attributed to prion protein genotype, strain, breed, clinical duration, dose, route and type of inoculum and the age at infection. The study aimed to describe the clinical signs in sheep infected with the BSE agent throughout its clinical course to determine whether the clinical signs were as variable as described for classical scrapie in sheep. The clinical signs were compared to BSE-negative sheep to assess if disease-specific clinical markers exist. Results Forty-seven (34% of 139 sheep, which comprised 123 challenged sheep and 16 undosed controls, were positive for BSE. Affected sheep belonged to five different breeds and three different genotypes (ARQ/ARQ, VRQ/VRQ and AHQ/AHQ. None of the controls or BSE exposed sheep with ARR alleles were positive. Pruritus was present in 41 (87% BSE positive sheep; the remaining six were judged to be pre-clinically infected. Testing of the response to scratching along the dorsum of a sheep proved to be a good indicator of clinical disease with a test sensitivity of 85% and specificity of 98% and usually coincided with weight loss. Clinical signs that were displayed significantly earlier in BSE positive cases compared to negative cases were behavioural changes, pruritic behaviour, a positive scratch test, alopecia, skin lesions, teeth grinding, tremor, ataxia, loss of weight and loss of body condition. The frequency and severity of each specific clinical sign usually increased with the progression of disease over a period of 16–20 weeks. Conclusion Our results suggest that BSE in sheep presents with relatively uniform clinical signs, with pruritus of increased severity and abnormalities in behaviour or movement as the disease progressed. Based on the studied sheep, these clinical features appear to

  7. An acoustic prion assay

    Directory of Open Access Journals (Sweden)

    Gordon Hayward

    2016-12-01

    Full Text Available An acoustic prion assay has been demonstrated for sheep brain samples. Only five false positives and no false negatives were observed in a test of 45 positive and 45 negative samples. The acoustic prion sensor was constructed using a thickness shear mode quartz resonator coated with a covalently bound recombinant prion protein. The characteristic indicator of a scrapie infected sheep brain sample was an observed shoulder in the frequency decrease in response to a sample.The response of the sensor aligns with a conformational shift in the surface protein and with the propagation mechanism of the disease. This alignment is evident in the response timing and shape, dependence on concentration, cross species behaviour and impact of blood plasma. This alignment is far from sufficient to prove the mechanism of the sensor but it does offer the possibility of a rapid and inexpensive additional tool to explore prion disease. Keywords: Prions, Thickness shear mode quartz sensor

  8. Doenças de ovinos diagnosticadas no Laboratório de Anatomia Patológica Animal da Universidade Federal de Mato Grosso do Sul (1996-2010 Sheep diseases diagnosed at the Laboratory of Animal Pathology, Federal University of Mato Grosso do Sul, Brazil (1996-2010

    Directory of Open Access Journals (Sweden)

    Thiago L. Almeida

    2013-01-01

    Full Text Available Nas últimas décadas a pecuária ovina cresceu significativamente no Brasil. Concomitantemente, grupos de pesquisas e laboratórios de diagnósticos realizam estudos retrospectivos com a finalidade de fornecer subsídios técnico-científicos para os médicos veterinários. Desta forma, realizou-se um estudo de prevalência nos arquivos do Laboratório de Anatomia Patológica Animal (LAP da Universidade Federal de Mato Grosso do Sul (UFMS no período de Janeiro de 1996 a Dezembro de 2010. O Laboratório de Bacteriologia da UFMS e o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul forneceram apoio diagnóstico nos casos de mannheimiose pulmonar e scrapie, respectivamente. Os laudos da espécie ovina foram revisados e agrupados em conclusivos e inconclusivos, dos quais foram excluídos os casos experimentais e de outros estados e países. Os casos conclusivos foram classificados de acordo com a etiologia da doença. Os exames da espécie ovina somaram 331 laudos (3,97 % de um total de 8.333 casos diagnosticados no período. Destes, foram excluídos sessenta e quatro (19,3% casos experimentais e materiais oriundos de outros estados ou países. Dos 267 casos remanescentes, 87 (32,6% foram inconclusivos e 180 (67,4% considerados conclusivos, sendo 60 (33,3% doenças infecciosas e parasitárias; 45 (25% intoxicações e toxi-infecções; 41 (22,8% "lesões sem causa definida"; 22 (12,2% doenças metabólicas e nutricionais; 10 (5,6% foram classificadas como "outros distúrbios" e 2 (1,1% neoplasmas. A hemoncose, intoxicação por Brachiaria spp., pleuropneumonias, broncopneumonias, pneumonias fibrinonecrosante ou fibrinossupurativa sem causa definida e a intoxicação por cobre foram as doenças mais prevalentes no período estudado. Dois casos de scrapie foram diagnosticados no período.Sheep farming has increased significantly in Brazil during the last decades. Concurrently, research groups and diagnostic laboratories

  9. An Enzymatic Treatment of Soil-Bound Prions Effectively Inhibits Replication ▿

    Science.gov (United States)

    Saunders, Samuel E.; Bartz, Jason C.; Vercauteren, Kurt C.; Bartelt-Hunt, Shannon L.

    2011-01-01

    Chronic wasting disease (CWD) and scrapie can be transmitted through indirect environmental routes, possibly via soil, and a practical decontamination strategy for prion-contaminated soil is currently unavailable. In the laboratory, an enzymatic treatment under environmentally relevant conditions (22°C, pH 7.4) can degrade soil-bound PrPSc below the limits of Western blot detection. We developed and used a quantitative serial protein misfolding cyclic amplification (PMCA) protocol to characterize the amplification efficiency of treated soil samples relative to controls of known infectious titer. Our results suggest large (104- to >106-fold) decreases in soil-bound prion infectivity following enzyme treatment, demonstrating that a mild enzymatic treatment could effectively reduce the risk of prion disease transmission via soil or other environmental surfaces. PMID:21571886

  10. Approaching the largest ‘API’: extracting information from the Internet with Python

    Directory of Open Access Journals (Sweden)

    Jonathan E. Germann

    2018-02-01

    Full Text Available This article explores the need for libraries to algorithmically access and manipulate the world’s largest API: the Internet. The billions of pages on the ‘Internet API’ (HTTP, HTML, CSS, XPath, DOM, etc. are easily accessible and manipulable. Libraries can assist in creating meaning through the datafication of information on the world wide web. Because most information is created for human consumption, some programming is required for automated extraction. Python is an easy-to-learn programming language with extensive packages and community support for web page automation. Four packages (Urllib, Selenium, BeautifulSoup, Scrapy in Python can automate almost any web page for all sized projects. An example warrant data project is explained to illustrate how well Python packages can manipulate web pages to create meaning through assembling custom datasets.

  11. Real-time visualization of prion transport in single live cells using quantum dots

    International Nuclear Information System (INIS)

    Luo, Kan; Li, Shu; Xie, Min; Wu, Di; Wang, WenXi; Chen, Rui; Huang, Liqin; Huang, Tao; Pang, Daiwen; Xiao, Gengfu

    2010-01-01

    Prion diseases are fatal neurodegenerative disorders resulting from structural conversion of the cellular isoform of PrP C to the infectious scrapie isoform PrP Sc . It is believed that such structural alteration may occur within the internalization pathway. However, there is no direct evidence to support this hypothesis. Employing quantum dots (QDs) as a probe, we have recorded a real-time movie demonstrating the process of prion internalization in a living cell for the first time. The entire internalization process can be divided into four discrete but connected stages. In addition, using methyl-beta-cyclodextrin to disrupt cell membrane cholesterol, we show that lipid rafts play an important role in locating cellular PrP C to the cell membrane and in initiating PrP C endocytosis.

  12. Real-time visualization of prion transport in single live cells using quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kan [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Li, Shu [AIDS Research Centre, Institute of Pathogen Biology, Chinese Academy of Medical Science, Beijing 100730 (China); Xie, Min [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Wu, Di; Wang, WenXi; Chen, Rui; Huang, Liqin; Huang, Tao [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Pang, Daiwen, E-mail: dwpang@whu.edu.cn [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China)

    2010-04-09

    Prion diseases are fatal neurodegenerative disorders resulting from structural conversion of the cellular isoform of PrP{sup C} to the infectious scrapie isoform PrP{sup Sc}. It is believed that such structural alteration may occur within the internalization pathway. However, there is no direct evidence to support this hypothesis. Employing quantum dots (QDs) as a probe, we have recorded a real-time movie demonstrating the process of prion internalization in a living cell for the first time. The entire internalization process can be divided into four discrete but connected stages. In addition, using methyl-beta-cyclodextrin to disrupt cell membrane cholesterol, we show that lipid rafts play an important role in locating cellular PrP{sup C} to the cell membrane and in initiating PrP{sup C} endocytosis.

  13. Bitemporal hypometabolism in Creutzfeldt-Jakob disease measured by positron emission tomography with [18F]-2-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Friedland, R.P.; Prusiner, S.B.; Jagust, W.J.; Budinger, T.F.; Davis, R.L.

    1984-01-01

    It is well established that Creutzfeldt-Jakob disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54-year-old man with autopsy confirmed CJD using [18F]-2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. Temporal lobe hypometabolism with hemispheric asymmetry was observed. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer disease (AD). The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the possibility that AD may be caused by a slow infectious prion

  14. Bovine spongiform encephalopathy: is it time to relax BSE-related measures in the context of international trade?

    Science.gov (United States)

    Matthews, D; Adkin, A

    2011-04-01

    Bovine spongiform encephalopathy (BSE) has presented serious challenges to both the World Organisation for Animal Health and national governments, in defining and implementing appropriate national control measures, and in agreeing trade rules that permit safe trade in cattle and bovine products. Precautionary trade rules were initially necessary, based upon the science of sheep scrapie, but research into BSE later enabled BSE-specific trade rules to be developed. As a result, current rules on trade are underpinned by a sound body of knowledge on BSE. Declining epidemics in most affected countries confirm the appropriateness of current precautions. Nevertheless, risk is primarily dependent on the prevalence of infection with BSE. In the face of low prevalence scenarios, certain precautionary measures in the Terrestrial Animal Health Code may now be considered excessive. A thorough review is therefore deemed appropriate.

  15. Ovine recombinant PrP as an inhibitor of ruminant prion propagation in vitro.

    Science.gov (United States)

    Workman, Rob G; Maddison, Ben C; Gough, Kevin C

    2017-07-04

    Prion diseases are fatal and incurable neurodegenerative diseases of humans and animals. Despite years of research, no therapeutic agents have been developed that can effectively manage or reverse disease progression. Recently it has been identified that recombinant prion proteins (rPrP) expressed in bacteria can act as inhibitors of prion replication within the in vitro prion replication system protein misfolding cyclic amplification (PMCA). Here, within PMCA reactions amplifying a range of ruminant prions including distinct Prnp genotypes/host species and distinct prion strains, recombinant ovine VRQ PrP displayed consistent inhibition of prion replication and produced IC50 values of 122 and 171 nM for ovine scrapie and bovine BSE replication, respectively. These findings illustrate the therapeutic potential of rPrPs with distinct TSE diseases.

  16. Bitemporal hypometabolism in Creutzfeldt-Jakob disease measured by positron emission tomography with (/sup 18/F)-2-fluorodeoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, R.P.; Prusiner, S.B.; Jagust, W.J.; Budinger, T.F.; Davis, R.L.

    1984-10-01

    It is well established that Creutzfeldt-Jakob disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54-year-old man with autopsy confirmed CJD using (18F)-2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. Temporal lobe hypometabolism with hemispheric asymmetry was observed. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer disease (AD). The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the possibility that AD may be caused by a slow infectious prion.

  17. Encefalopatía Espongiforme Bovina

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    Gonzalo Luque Forero

    1992-09-01

    Full Text Available

    En 1986 se comprobó en Inglaterra que una entidad clínica de los bovinos caracterizada por excitabilidad, cambios de comportamiento, hiperestesia, agresividad, resistencia para entrar a la sala de ordeño, correspondía histopatológicamente a una encefalopatía espongiforme, sorprendentemente similar a la del scrapie de ovinos y caprinos y a la de las enfermedades humanas de Creutzfeldt-Jacob (C-J y Kuru. (2

    Esta encefalopatía espongiforme de los bovinos alcanzó proporciones epidémicas; para Febrero de 1990 el total de casos confirmados era de 9.838 procedentes de 5.659 hatos. La situación llevó a la eliminación de miles de cabezas de ganado, a un ritmo de 200 a 300 animales por semana, y a la prohibición del expendio de carne y vísceras de animales infectados para consumo humano. Algunos países de Europa Occidental, Estados Unidos y Canadá aplicaron drásticas medidas para impedir la importación de bovinos provenientes de Inglaterra y sus subproductos. (2,5,7

    La causa más probable de las manifestaciones en los bovinos es que se hayan infectado al consumir alimentos concentrados que contenían proteínas y subproductos ovinos provenientes de ovejas infectadas con el agente del scrapie. Con la circunstancia de que en la década de 1970 se cambió en Inglaterra el sistema de extraer la grasa y la carne de las ovejas por medio de solventes y elevadas temperaturas por un proceso en frío. El período de incubación de la encefalopatía espongiforme de los bovinos está entre los dos y medio y los ocho años. (2,9

    El scrapie es una enfermedad de ovinos y a veces de caprinos, caracterizada por trastornos nerviosos como excitabilidad, tremor de la cabeza, ataxia de los miembros anteriores, incoordinación para la marcha e incapacidad para mantenerse en pie. Hay también intenso prurito cutáneo que lleva a que los animales se froten constantemente contra objetos fijos y se observa además caída de la lana. La

  18. A novel class of potential prion drugs: preliminary in vitro and in vivo data for multilayer coated gold nanoparticles.

    Science.gov (United States)

    Ai Tran, Hoang Ngoc; Sousa, Fernanda; Moda, Fabio; Mandal, Subhra; Chanana, Munish; Vimercati, Chiara; Morbin, Michela; Krol, Silke; Tagliavini, Fabrizio; Legname, Giuseppe

    2010-12-01

    Gold nanoparticles coated with oppositely charged polyelectrolytes, such as polyallylamine hydrochloride and polystyrenesulfonate, were examined for potential inhibition of prion protein aggregation and prion (PrPSc) conversion and replication. Different coatings, finishing with a positive or negative layer, were tested, and different numbers of layers were investigated for their ability to interact and reduce the accumulation of PrPSc in scrapie prion infected ScGT1 and ScN2a cells. The particles efficiently hampered the accumulation of PrPSc in ScN2a cells and showed curing effects on ScGT1 cells with a nanoparticle concentration in the picomolar range. Finally, incubation periods of prion-infected mice treated with nanomolar concentrations of gold nanoparticles were significantly longer compared to untreated controls.

  19. Mutated but Not Deleted Ovine PrP(C) N-Terminal Polybasic Region Strongly Interferes with Prion Propagation in Transgenic Mice.

    Science.gov (United States)

    Khalifé, Manal; Reine, Fabienne; Paquet-Fifield, Sophie; Castille, Johan; Herzog, Laetitia; Vilotte, Marthe; Moudjou, Mohammed; Moazami-Goudarzi, Katayoun; Makhzami, Samira; Passet, Bruno; Andréoletti, Olivier; Vilette, Didier; Laude, Hubert; Béringue, Vincent; Vilotte, Jean-Luc

    2016-02-01

    Mammalian prions are proteinaceous infectious agents composed of misfolded assemblies of the host-encoded, cellular prion protein (PrP). Physiologically, the N-terminal polybasic region of residues 23 to 31 of PrP has been shown to be involved in its endocytic trafficking and interactions with glycosaminoglycans or putative ectodomains of membrane-associated proteins. Several recent reports also describe this PrP region as important for the toxicity of mutant prion proteins and the efficiency of prion propagation, both in vitro and in vivo. The question remains as to whether the latter observations made with mouse PrP and mouse prions would be relevant to other PrP species/prion strain combinations given the dramatic impact on prion susceptibility of minimal amino acid substitutions and structural variations in PrP. Here, we report that transgenic mouse lines expressing ovine PrP with a deletion of residues 23 to 26 (KKRP) or mutated in this N-terminal region (KQHPH instead of KKRPK) exhibited a variable, strain-dependent susceptibility to prion infection with regard to the proportion of affected mice and disease tempo relative to findings in their wild-type counterparts. Deletion has no major effect on 127S scrapie prion pathogenesis, whereas mutation increased by almost 3-fold the survival time of the mice. Deletion marginally affected the incubation time of scrapie LA19K and ovine bovine spongiform encephalopathy (BSE) prions, whereas mutation caused apparent resistance to disease. Recent reports suggested that the N-terminal polybasic region of the prion protein could be a therapeutic target to prevent prion propagation or toxic signaling associated with more common neurodegenerative diseases such as Alzheimer's disease. Mutating or deleting this region in ovine PrP completes the data previously obtained with the mouse protein by identifying the key amino acid residues involved. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  20. An assessment of the long-term persistence of prion infectivity in aquatic environments

    International Nuclear Information System (INIS)

    Marín-Moreno, Alba; Espinosa, Juan-Carlos; Fernández-Borges, Natalia; Píquer, Juan; Girones, Rosina; Andreoletti, Olivier; Torres, Juan-María

    2016-01-01

    The environment plays a key role in horizontal transmission of prion diseases, since prions are extremely resistant to classical inactivation procedures. In prior work, we observed the high stability of bovine spongiform encephalopathy (BSE) infectivity when these prions were incubated in aqueous media such as phosphate-buffered saline (PBS) or wastewater for nearly nine months. As a continuation of this experiment, the same samples were maintained in PBS or wastewater for five additional years and residual BSE infectivity was assessed in bovine PrP C transgenic mice. Over this long time period (more than six years), BSE infectivity was reduced by three and one orders of magnitude in wastewater and PBS respectively. To rule out a possible agent specific effect, sheep scrapie prions were subjected to the same experimental protocol, using eight years as the experimental end-point. No significant reduction in scrapie infectivity was observed over the first nine months of wastewater incubation while PBS incubation for eight years only produced a two logarithmic unit reduction in infectivity. By contrast, the dynamics of PrP Res persistence was different, disappearing progressively over the first year. The long persistence of prion infectivity observed in this study for two different agents provides supporting evidence of the assumed high stability of these agents in aquatic environments and that environmental processes or conventional wastewater treatments with low retention times would have little impact on prion infectivity. These results could have great repercussions in terms of risk assessment and safety for animals and human populations. - Highlights: • Prion infectivity resists long term incubations in aquatic environments. • Infectivity persistence in wastewater is reduced when compared to PBS. • In this study PrPRes fails as a marker for prion detection. • Mice bioassay is the most powerful tool for assessing prion presence. • Wastewater conventional

  1. Prion propagation and toxicity occur in vitro with two-phase kinetics specific to strain and neuronal type.

    Science.gov (United States)

    Hannaoui, Samia; Maatouk, Layal; Privat, Nicolas; Levavasseur, Etienne; Faucheux, Baptiste A; Haïk, Stéphane

    2013-03-01

    Prion diseases, or transmissible spongiform encephalopathies (TSEs), are fatal neurodegenerative disorders that occur in humans and animals. The neuropathological hallmarks of TSEs are spongiosis, glial proliferation, and neuronal loss. The only known specific molecular marker of TSEs is the abnormal isoform (PrP(Sc)) of the host-encoded prion protein (PrP(C)), which accumulates in the brain of infected subjects and forms infectious prion particles. Although this transmissible agent lacks a specific nucleic acid component, several prion strains have been isolated. Prion strains are characterized by differences in disease outcome, PrP(Sc) distribution patterns, and brain lesion profiles at the terminal stage of the disease. The molecular factors and cellular mechanisms involved in strain-specific neuronal tropism and toxicity remain largely unknown. Currently, no cellular model exists to facilitate in vitro studies of these processes. A few cultured cell lines that maintain persistent scrapie infections have been developed, but only two of them have shown the cytotoxic effects associated with prion propagation. In this study, we have developed primary neuronal cultures to assess in vitro neuronal tropism and toxicity of different prion strains (scrapie strains 139A, ME7, and 22L). We have tested primary neuronal cultures enriched in cerebellar granular, striatal, or cortical neurons. Our results showed that (i) a strain-specific neuronal tropism operated in vitro; (ii) the cytotoxic effect varied among strains and neuronal cell types; (iii) prion propagation and toxicity occurred in two kinetic phases, a replicative phase followed by a toxic phase; and (iv) neurotoxicity peaked when abnormal PrP accumulation reached a plateau.

  2. Prion infected meat-and-bone meal is still infectious after biodiesel production.

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    Cathrin E Bruederle

    2008-08-01

    Full Text Available The epidemic of bovine spongiform encephalopathy (BSE has led to a world-wide drop in the market for beef by-products, such as Meat-and-Bone Meal (MBM, a fat-containing but mainly proteinaceaous product traditionally used as an animal feed supplement. While normal rendering is insufficient, the production of biodiesel from MBM has been suggested to destroy infectivity from transmissible spongiform encephalopathies (TSEs. In addition to producing fuel, this method simultaneously generates a nutritious solid residue. In our study we produced biodiesel from MBM under defined conditions using a modified form of alkaline methanolysis. We evaluated the presence of prion in the three resulting phases of the biodiesel reaction (Biodiesel, Glycerol and Solid Residue in vitro and in vivo. Analysis of the reaction products from 263K scrapie infected MBM led to no detectable immunoreactivity by Western Blot. Importantly, and in contrast to the biochemical results the solid MBM residue from the reaction retained infectivity when tested in an animal bioassay. Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.

  3. An assessment of the long-term persistence of prion infectivity in aquatic environments

    Energy Technology Data Exchange (ETDEWEB)

    Marín-Moreno, Alba; Espinosa, Juan-Carlos; Fernández-Borges, Natalia; Píquer, Juan [Centro de Investigación en Sanidad Animal, CISA-INIA, Carretera Algete-El Casar S/n, Valdeolmos, 28130 Madrid (Spain); Girones, Rosina [Department of Microbiology, University of Barcelona, Diagonal 643, 08028 Barcelona (Spain); Andreoletti, Olivier [UMR INRA-ENVT 1225, Interactions Hôte Agent Pathogène, Ecole Nationale Vétérinaire de Toulouse, Toulouse (France); Torres, Juan-María, E-mail: jmtorres@inia.es [Centro de Investigación en Sanidad Animal, CISA-INIA, Carretera Algete-El Casar S/n, Valdeolmos, 28130 Madrid (Spain)

    2016-11-15

    The environment plays a key role in horizontal transmission of prion diseases, since prions are extremely resistant to classical inactivation procedures. In prior work, we observed the high stability of bovine spongiform encephalopathy (BSE) infectivity when these prions were incubated in aqueous media such as phosphate-buffered saline (PBS) or wastewater for nearly nine months. As a continuation of this experiment, the same samples were maintained in PBS or wastewater for five additional years and residual BSE infectivity was assessed in bovine PrP{sup C} transgenic mice. Over this long time period (more than six years), BSE infectivity was reduced by three and one orders of magnitude in wastewater and PBS respectively. To rule out a possible agent specific effect, sheep scrapie prions were subjected to the same experimental protocol, using eight years as the experimental end-point. No significant reduction in scrapie infectivity was observed over the first nine months of wastewater incubation while PBS incubation for eight years only produced a two logarithmic unit reduction in infectivity. By contrast, the dynamics of PrP{sup Res} persistence was different, disappearing progressively over the first year. The long persistence of prion infectivity observed in this study for two different agents provides supporting evidence of the assumed high stability of these agents in aquatic environments and that environmental processes or conventional wastewater treatments with low retention times would have little impact on prion infectivity. These results could have great repercussions in terms of risk assessment and safety for animals and human populations. - Highlights: • Prion infectivity resists long term incubations in aquatic environments. • Infectivity persistence in wastewater is reduced when compared to PBS. • In this study PrPRes fails as a marker for prion detection. • Mice bioassay is the most powerful tool for assessing prion presence. • Wastewater

  4. Estimating chronic wasting disease susceptibility in cervids using real-time quaking-induced conversion.

    Science.gov (United States)

    Haley, Nicholas J; Rielinger, Rachel; Davenport, Kristen A; O'Rourke, Katherine; Mitchell, Gordon; Richt, Jürgen A

    2017-11-01

    In mammals, susceptibility to prion infection is primarily modulated by the host's cellular prion protein (PrP C ) sequence. In the sheep scrapie model, a graded scale of susceptibility has been established both in vivo and in vitro based on PrP C amino acids 136, 154 and 171, leading to global breeding programmes to reduce the prevalence of scrapie in sheep. Chronic wasting disease (CWD) resistance in cervids is often characterized as decreased prevalence and/or protracted disease progression in individuals with specific alleles; at present, no PrP C allele conferring absolute resistance in cervids has been identified. To model the susceptibility of various naturally occurring and hypothetical cervid PrP C alleles in vitro, we compared the amplification rates and amyloid extension efficiencies of eight distinct CWD isolates in recombinant cervid PrP C substrates using real-time quaking-induced conversion. We hypothesized that the in vitro conversion characteristics of these isolates in cervid substrates would correlate to in vivo susceptibility - permitting susceptibility prediction for the rare alleles found in nature. We also predicted that hypothetical alleles with multiple resistance-associated codons would be more resistant to in vitro conversion than natural alleles with a single resistant codon. Our studies demonstrate that in vitro conversion metrics align with in vivo susceptibility, and that alleles with multiple amino acid substitutions, each influencing resistance independently, do not necessarily contribute additively to conversion resistance. Importantly, we found that the naturally occurring whitetail deer QGAK substrate exhibited the slowest amplification rate among those evaluated, suggesting that further investigation of this allele and its resistance in vivo is warranted.

  5. Genetic prion disease: no role for the immune system in disease pathogenesis?

    Science.gov (United States)

    Friedman-Levi, Yael; Binyamin, Orli; Frid, Kati; Ovadia, Haim; Gabizon, Ruth

    2014-08-01

    Prion diseases, which can manifest by transmissible, sporadic or genetic etiologies, share several common features, such as a fatal neurodegenerative outcome and the aberrant accumulation of proteinase K (PK)-resistant PrP forms in the CNS. In infectious prion diseases, such as scrapie in mice, prions first replicate in immune organs, then invade the CNS via ascending peripheral tracts, finally causing death. Accelerated neuroinvasion and death occurs when activated prion-infected immune cells infiltrate into the CNS, as is the case for scrapie-infected mice induced for experimental autoimmune encephalomyelitis (EAE), a CNS inflammatory insult. To establish whether the immune system plays such a central role also in genetic prion diseases, we induced EAE in TgMHu2ME199K mice, a line mimicking for late onset genetic Creutzfeldt Jacob disease (gCJD), a human prion disease. We show here that EAE induction of TgMHu2ME199K mice neither accelerated nor aggravated prion disease manifestation. Concomitantly, we present evidence that PK-resistant PrP forms were absent from CNS immune infiltrates, and most surprisingly also from lymph nodes and spleens of TgMHu2ME199K mice at all ages and stages of disease. These results imply that the mechanism of genetic prion disease differs widely from that of the infectious presentation, and that the conversion of mutant PrPs into PK resistant forms occurs mostly/only in the CNS. If the absence of pathogenic PrP forms form immune organs is also true for gCJD patients, it may suggest their blood is devoid of prion infectivity. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Overexpression of PLK3 Mediates the Degradation of Abnormal Prion Proteins Dependent on Chaperone-Mediated Autophagy.

    Science.gov (United States)

    Wang, Hui; Tian, Chan; Sun, Jing; Chen, Li-Na; Lv, Yan; Yang, Xiao-Dong; Xiao, Kang; Wang, Jing; Chen, Cao; Shi, Qi; Shao, Qi-Xiang; Dong, Xiao-Ping

    2017-08-01

    Polo-like kinase 3 (PLK3) is the main cause of cell cycle reentry-related neuronal apoptosis which has been implicated in the pathogenesis of prion diseases. Previous work also showed the regulatory activity of exogenous PLK3 on the degradation of PrP (prion protein) mutants and pathogenic PrP Sc ; however, the precise mechanisms remain unknown. In this study, we identified that the overexpression of PLK3-mediated degradation of PrP mutant and PrP Sc was repressed by lysosome rather than by proteasomal and macroautophagy inhibitors. Core components of chaperone-mediated autophagy (CMA) effectors, lysosome-associated membrane protein type 2A (LAMP2a), and heat shock cognate protein 70 (Hsc70) are markedly decreased in the HEK293T cells expressing PrP mutant and scrapie-infected cell line SMB-S15. Meanwhile, PrP mutant showed ability to interact with LAMP2a and Hsc70. Overexpression of PLK3 sufficiently increased the cellular levels of LAMP2a and Hsc70, accompanying with declining the accumulations of PrP mutant and PrP Sc . The kinase domain (KD) of PLK3 was responsible for elevating LAMP2a and Hsc70. Knockdown of endogenous PLK3 enhanced the activity of macroautophagy in the cultured cells. Moreover, time-dependent reductions of LAMP2a and Hsc70 were also observed in the brain tissues of hamster-adapted scrapie agent 263K-infected hamsters, indicating an impairment of CMA during prion infection. Those data indicate that the overexpression of PLK3-mediated degradation of abnormal PrP is largely dependent on CMA pathway.

  7. Plasminogen-based capture combined with amplification technology for the detection of PrP(TSE in the pre-clinical phase of infection.

    Directory of Open Access Journals (Sweden)

    Christiane Segarra

    Full Text Available BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD is a neurodegenerative infectious disorder, characterized by a prominent accumulation of pathological isoforms of the prion protein (PrP(TSE in the brain and lymphoid tissues. Since the publication in the United Kingdom of four apparent vCJD cases following transfusion of red blood cells and one apparent case following treatment with factor VIII, the presence of vCJD infectivity in the blood seems highly probable. For effective blood testing of vCJD individuals in the preclinical or clinical phase of infection, it is considered necessary that assays detect PrP(TSE concentrations in the femtomolar range. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a three-step assay that firstly captures PrP(TSE from infected blood using a plasminogen-coated magnetic-nanobead method prior to its serial amplification via protein misfolding cyclic amplification (PMCA and specific PrP(TSE detection by western blot. We achieved a PrP(TSE capture yield of 95% from scrapie-infected material. We demonstrated the possibility of detecting PrP(TSE in white blood cells, in buffy coat and in plasma isolated from the blood of scrapie-infected sheep collected at the pre-clinical stage of the disease. The test also allowed the detection of PrP(TSE in human plasma spiked with a 10(-8 dilution of vCJD-infected brain homogenate corresponding to the level of sensitivity (femtogram required for the detection of the PrP(TSE in asymptomatic carriers. The 100% specificity of the test was revealed using a blinded panel comprising 96 human plasma samples. CONCLUSION/SIGNIFICANCE: We have developed a sensitive and specific amplification assay allowing the detection of PrP(TSE in the plasma and buffy coat fractions of blood collected at the pre-clinical phase of the disease. This assay represents a good candidate as a confirmatory assay for the presence of PrP(TSE in blood of patients displaying positivity in large scale screening

  8. EU-approved rapid tests for bovine spongiform encephalopathy detect atypical forms: a study for their sensitivities.

    Directory of Open Access Journals (Sweden)

    Daniela Meloni

    Full Text Available Since 2004 it become clear that atypical bovine spongiform encephalopthies (BSEs exist in cattle. Whenever their detection has relied on active surveillance plans implemented in Europe since 2001 by rapid tests, the overall and inter-laboratory performance of these diagnostic systems in the detection of the atypical strains has not been studied thoroughly to date. To fill this gap, the present study reports on the analytical sensitivity of the EU-approved rapid tests for atypical L- and H-type and classical BSE in parallel. Each test was challenged with two dilution series, one created from a positive pool of the three BSE forms according to the EURL standard method of homogenate preparation (50% w/v and the other as per the test kit manufacturer's instructions. Multilevel logistic models and simple logistic models with the rapid test as the only covariate were fitted for each BSE form analyzed as directed by the test manufacturer's dilution protocol. The same schemes, but excluding the BSE type, were then applied to compare test performance under the manufacturer's versus the water protocol. The IDEXX HerdChek ® BSE-scrapie short protocol test showed the highest sensitivity for all BSE forms. The IDEXX® HerdChek BSE-scrapie ultra short protocol, the Prionics®--Check WESTERN and the AJ Roboscreen® BetaPrion tests showed similar sensitivities, followed by the Roche® PrionScreen, the Bio-Rad® TeSeE™ SAP and the Prionics®--Check PrioSTRIP in descending order of analytical sensitivity. Despite these differences, the limit of detection of all seven rapid tests against the different classes of material set within a 2 log(10 range of the best-performing test, thus meeting the European Food Safety Authority requirement for BSE surveillance purposes. These findings indicate that not many atypical cases would have been missed surveillance since 2001 which is important for further epidemiological interpretations of the sporadic character of

  9. Resistance of soil-bound prions to rumen digestion.

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    Samuel E Saunders

    Full Text Available Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrP(c from complete digestion, while both unbound and soil-bound infectious PrP(Sc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD and scrapie in the environment.

  10. Investigation of the effects of experimental autolysis on the detection of abnormal prion protein in lymphoid and central nervous system tissues from elk and sheep using the Western blotting method.

    Science.gov (United States)

    Huang, Hongsheng; Soutyrine, Andrei; Rendulich, Jasmine; O'Rourke, Katherine; Balachandran, Aru

    2011-01-01

    Tissues unsuitable for standard immunohistochemical and histopathological examinations for chronic wasting disease (CWD) in cervids and for scrapie in sheep are frequently submitted for testing. This study investigated the effects of experimental autolysis on the detection of abnormal prion protein (PrPsc) in lymphoid and central nervous system (CNS) tissues from elk and sheep. The PrPsc was detected using a Western blotting (WB) test following PrPsc enrichment using sodium phosphotungstic acid (PTA) precipitation (PTA-WB). A commercial enzyme-linked immunosorbent assay (ELISA) was used as a reference test for quantitative measurement. This study showed that the amount of PrPsc in lymphoid and CNS tssues from elk and sheep decreased gradually as a result of autolysis, but PrPsc was still detectable after 5 and 15 d incubation at 37°C by PTA-WB for all lymphoid and CNS samples. The results of the ELISA supported those of PTA-WB, particularly for CNS tissues. In conclusion, autolysis at 37°C for 15 d would not significantly affect the detection of PrPsc in lymphoid and CNS tissues by WB and ELISA and, particularly, PTA-WB is a valuable and alternative confirmatory test to detect PrPsc in autolyzed lymphoid and CNS samples.

  11. Prions and animal transmissible spongiform encephalopathies

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    Juntes Polona

    2017-01-01

    Full Text Available Background. Transmissible spongiform encephalopathies (TSEs or prion diseases are a unique group of neurodegenerative diseases of animals and humans, which always have a fatal outcome and are transmissible among animals of the same or different species. Scope and Approach. The aim of this work is to review some recent data about animal TSEs, with the emphasis on their causative agents and zoonotic potential, and to discuss why the surveillance and control measures over animal TSEs should remain in force. Key Findings and Conclusions. We still have incomplete knowledge of prions and prion diseases. Scrapie has been present for a very long time and controlled with varied success. Bovine spongiform encephalopathy (BSE emerged unnoticed, and spread within a few years to epidemic proportions, entailing enormous economic consequences and public concerns. Currently, the classical BSE epidemic is under control, but atypical cases do, and probably will, persist in bovine populations. The Chronic Wasting Disease (CWD of the cervids has been spreading in North America and has recently been detected in Europe. Preventive measures for the control of classical BSE remain in force, including the feed ban and removal of specified risk materials. However, active BSE surveillance has considerably decreased. In the absence of such preventive and control measures, atypical BSE cases in healthy slaughtered bovines might persist in the human food chain, and BSE prions might resurface. Moreover, other prion strains might emerge and spread undetected if the appropriate preventive and surveillance measures were to cease, leaving behind inestimable consequences.

  12. Effects of solution chemistry and aging time on prion protein adsorption and replication of soil-bound prions.

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    Samuel E Saunders

    2011-04-01

    Full Text Available Prion interactions with soil may play an important role in the transmission of chronic wasting disease (CWD and scrapie. Prions are known to bind to a wide range of soil surfaces, but the effects of adsorption solution chemistry and long-term soil binding on prion fate and transmission risk are unknown. We investigated HY TME prion protein (PrP(Sc adsorption to soil minerals in aqueous solutions of phosphate buffered saline (PBS, sodium chloride, calcium chloride, and deionized water using western blotting. The replication efficiency of bound prions following adsorption in these solutions was also evaluated by protein misfolding cyclic amplification (PMCA. Aging studies investigated PrP(Sc desorption and replication efficiency up to one year following adsorption in PBS or DI water. Results indicate that adsorption solution chemistry can affect subsequent prion replication or desorption ability, especially after incubation periods of 30 d or longer. Observed effects were minor over the short-term (7 d or less. Results of long-term aging experiments demonstrate that unbound prions or prions bound to a diverse range of soil surfaces can readily replicate after one year. Our results suggest that while prion-soil interactions can vary with solution chemistry, prions bound to soil could remain a risk for transmitting prion diseases after months in the environment.

  13. Prion protein in milk.

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    Nicola Franscini

    Full Text Available BACKGROUND: Prions are known to cause transmissible spongiform encephalopathies (TSE after accumulation in the central nervous system. There is increasing evidence that prions are also present in body fluids and that prion infection by blood transmission is possible. The low concentration of the proteinaceous agent in body fluids and its long incubation time complicate epidemiologic analysis and estimation of spreading and thus the risk of human infection. This situation is particularly unsatisfactory for food and pharmaceutical industries, given the lack of sensitive tools for monitoring the infectious agent. METHODOLOGY/PRINCIPAL FINDINGS: We have developed an adsorption matrix, Alicon PrioTrap, which binds with high affinity and specificity to prion proteins. Thus we were able to identify prion protein (PrP(C--the precursor of prions (PrP(Sc--in milk from humans, cows, sheep, and goats. The absolute amount of PrP(C differs between the species (from microg/l range in sheep to ng/l range in human milk. PrP(C is also found in homogenised and pasteurised off-the-shelf milk, and even ultrahigh temperature treatment only partially diminishes endogenous PrP(C concentration. CONCLUSIONS/SIGNIFICANCE: In view of a recent study showing evidence of prion replication occurring in the mammary gland of scrapie infected sheep suffering from mastitis, the appearance of PrP(C in milk implies the possibility that milk of TSE-infected animals serves as source for PrP(Sc.

  14. PrP N-terminal domain triggers PrPSc-like aggregation of Dpl

    International Nuclear Information System (INIS)

    Erlich, Paul; Cesbron, Jean-Yves; Lemaire-Vieille, Catherine; Curt, Aurelie; Andrieu, Jean-Pierre; Schoehn, Guy; Jamin, Marc; Gagnon, Jean

    2008-01-01

    Transmissible spongiform encephalopathies are fatal neurodegenerative disorders thought to be transmitted by self-perpetuating conformational conversion of a neuronal membrane glycoprotein (PrP C , for 'cellular prion protein') into an abnormal state (PrP Sc , for 'scrapie prion protein'). Doppel (Dpl) is a protein that shares significant biochemical and structural homology with PrP C . In contrast to its homologue PrP C , Dpl is unable to participate in prion disease progression or to achieve an abnormal PrP Sc -like state. We have constructed a chimeric mouse protein, composed of the N-terminal domain of PrP C (residues 23-125) and the C-terminal part of Dpl (residues 58-157). This chimeric protein displays PrP-like biochemical and structural features; when incubated in presence of NaCl, the α-helical monomer forms soluble β-sheet-rich oligomers which acquire partial resistance to pepsin proteolysis in vitro, as do PrP oligomers. Moreover, the presence of aggregates akin to protofibrils is observed in soluble oligomeric species by electron microscopy

  15. Lions and prions and deer demise.

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    Michael W Miller

    Full Text Available BACKGROUND: Contagious prion diseases--scrapie of sheep and chronic wasting disease of several species in the deer family--give rise to epidemics that seem capable of compromising host population viability. Despite this prospect, the ecological consequences of prion disease epidemics in natural populations have received little consideration. METHODOLOGY/PRINCIPAL FINDINGS: Using a cohort study design, we found that prion infection dramatically lowered survival of free-ranging adult (>2-year-old mule deer (Odocoileus hemionus: estimated average life expectancy was 5.2 additional years for uninfected deer but only 1.6 additional years for infected deer. Prion infection also increased nearly fourfold the rate of mountain lions (Puma concolor preying on deer, suggesting that epidemics may alter predator-prey dynamics by facilitating hunting success. Despite selective predation, about one fourth of the adult deer we sampled were infected. High prevalence and low survival of infected deer provided a plausible explanation for the marked decline in this deer population since the 1980s. CONCLUSION: Remarkably high infection rates sustained in the face of intense predation show that even seemingly complete ecosystems may offer little resistance to the spread and persistence of contagious prion diseases. Moreover, the depression of infected populations may lead to local imbalances in food webs and nutrient cycling in ecosystems in which deer are important herbivores.

  16. Direct Detection of Soil-Bound Prions

    Science.gov (United States)

    Genovesi, Sacha; Leita, Liviana; Sequi, Paolo; Andrighetto, Igino; Sorgato, M. Catia; Bertoli, Alessandro

    2007-01-01

    Scrapie and chronic wasting disease are contagious prion diseases affecting sheep and cervids, respectively. Studies have indicated that horizontal transmission is important in sustaining these epidemics, and that environmental contamination plays an important role in this. In the perspective of detecting prions in soil samples from the field by more direct methods than animal-based bioassays, we have developed a novel immuno-based approach that visualises in situ the major component (PrPSc) of prions sorbed onto agricultural soil particles. Importantly, the protocol needs no extraction of the protein from soil. Using a cell-based assay of infectivity, we also report that samples of agricultural soil, or quartz sand, acquire prion infectivity after exposure to whole brain homogenates from prion-infected mice. Our data provide further support to the notion that prion-exposed soils retain infectivity, as recently determined in Syrian hamsters intracerebrally or orally challanged with contaminated soils. The cell approach of the potential infectivity of contaminated soil is faster and cheaper than classical animal-based bioassays. Although it suffers from limitations, e.g. it can currently test only a few mouse prion strains, the cell model can nevertheless be applied in its present form to understand how soil composition influences infectivity, and to test prion-inactivating procedures. PMID:17957252

  17. Direct detection of soil-bound prions.

    Directory of Open Access Journals (Sweden)

    Sacha Genovesi

    Full Text Available Scrapie and chronic wasting disease are contagious prion diseases affecting sheep and cervids, respectively. Studies have indicated that horizontal transmission is important in sustaining these epidemics, and that environmental contamination plays an important role in this. In the perspective of detecting prions in soil samples from the field by more direct methods than animal-based bioassays, we have developed a novel immuno-based approach that visualises in situ the major component (PrP(Sc of prions sorbed onto agricultural soil particles. Importantly, the protocol needs no extraction of the protein from soil. Using a cell-based assay of infectivity, we also report that samples of agricultural soil, or quartz sand, acquire prion infectivity after exposure to whole brain homogenates from prion-infected mice. Our data provide further support to the notion that prion-exposed soils retain infectivity, as recently determined in Syrian hamsters intracerebrally or orally challenged with contaminated soils. The cell approach of the potential infectivity of contaminated soil is faster and cheaper than classical animal-based bioassays. Although it suffers from limitations, e.g. it can currently test only a few mouse prion strains, the cell model can nevertheless be applied in its present form to understand how soil composition influences infectivity, and to test prion-inactivating procedures.

  18. Enzymatic Digestion of Chronic Wasting Disease Prions Bound to Soil

    Science.gov (United States)

    SAUNDERS, SAMUEL E.; BARTZ, JASON C.; VERCAUTEREN, KURT C.; BARTELT-HUNT, SHANNON L.

    2010-01-01

    Chronic wasting disease (CWD) and sheep scrapie can be transmitted via indirect environmental routes, and it is known that soil can serve as a reservoir of prion infectivity. Given the strong interaction between the prion protein (PrP) and soil, we hypothesized that binding to soil enhances prion resistance to enzymatic digestion, thereby facilitating prion longevity in the environment and providing protection from host degradation. We characterized the performance of a commercially available subtilisin enzyme, the Prionzyme, to degrade soil-bound and unbound CWD and HY TME PrP as a function of pH, temperature, and treatment time. The subtilisin enzyme effectively degraded PrP adsorbed to a wide range of soils and soil minerals below the limits of detection. Signal loss occurred rapidly at high pH (12.5) and within 7 d under conditions representative of the natural environment (pH 7.4, 22°C). We observed no apparent difference in enzyme effectiveness between bound and unbound CWD PrP. Our results show that although adsorbed prions do retain relative resistance to enzymatic digestion compared with other brain homogenate proteins, they can be effectively degraded when bound to soil. Our results also suggest a topical application of a subtilisin enzyme solution may be an effective decontamination method to limit disease transmission via environmental ‘hot spots’ of prion infectivity. PMID:20450190

  19. Prion protein β2–α2 loop conformational landscape

    Science.gov (United States)

    Caldarulo, Enrico; Wüthrich, Kurt; Parrinello, Michele

    2017-01-01

    In transmissible spongiform encephalopathies (TSEs), which are lethal neurodegenerative diseases that affect humans and a wide range of other mammalian species, the normal “cellular” prion protein (PrPC) is transformed into amyloid aggregates representing the “scrapie form” of the protein (PrPSc). Continued research on this system is of keen interest, since new information on the physiological function of PrPC in healthy organisms is emerging, as well as new data on the mechanism of the transformation of PrPC to PrPSc. In this paper we used two different approaches: a combination of the well-tempered ensemble (WTE) and parallel tempering (PT) schemes and metadynamics (MetaD) to characterize the conformational free-energy surface of PrPC. The focus of the data analysis was on an 11-residue polypeptide segment in mouse PrPC(121–231) that includes the β2–α2 loop of residues 167–170, for which a correlation between structure and susceptibility to prion disease has previously been described. This study includes wild-type mouse PrPC and a variant with the single-residue replacement Y169A. The resulting detailed conformational landscapes complement in an integrative manner the available experimental data on PrPC, providing quantitative insights into the nature of the structural transition-related function of the β2–α2 loop. PMID:28827331

  20. Prion protein β2-α2 loop conformational landscape.

    Science.gov (United States)

    Caldarulo, Enrico; Barducci, Alessandro; Wüthrich, Kurt; Parrinello, Michele

    2017-09-05

    In transmissible spongiform encephalopathies (TSEs), which are lethal neurodegenerative diseases that affect humans and a wide range of other mammalian species, the normal "cellular" prion protein ([Formula: see text]) is transformed into amyloid aggregates representing the "scrapie form" of the protein ([Formula: see text]). Continued research on this system is of keen interest, since new information on the physiological function of [Formula: see text] in healthy organisms is emerging, as well as new data on the mechanism of the transformation of [Formula: see text] to [Formula: see text] In this paper we used two different approaches: a combination of the well-tempered ensemble (WTE) and parallel tempering (PT) schemes and metadynamics (MetaD) to characterize the conformational free-energy surface of [Formula: see text] The focus of the data analysis was on an 11-residue polypeptide segment in mouse [Formula: see text](121-231) that includes the [Formula: see text]2-[Formula: see text]2 loop of residues 167-170, for which a correlation between structure and susceptibility to prion disease has previously been described. This study includes wild-type mouse [Formula: see text] and a variant with the single-residue replacement Y169A. The resulting detailed conformational landscapes complement in an integrative manner the available experimental data on [Formula: see text], providing quantitative insights into the nature of the structural transition-related function of the [Formula: see text]2-[Formula: see text]2 loop.

  1. Impact of strong selection for the PrP major gene on genetic variability of four French sheep breeds (Open Access publication

    Directory of Open Access Journals (Sweden)

    Pantano Thais

    2008-11-01

    Full Text Available Abstract Effective selection on the PrP gene has been implemented since October 2001 in all French sheep breeds. After four years, the ARR "resistant" allele frequency increased by about 35% in young males. The aim of this study was to evaluate the impact of this strong selection on genetic variability. It is focussed on four French sheep breeds and based on the comparison of two groups of 94 animals within each breed: the first group of animals was born before the selection began, and the second, 3–4 years later. Genetic variability was assessed using genealogical and molecular data (29 microsatellite markers. The expected loss of genetic variability on the PrP gene was confirmed. Moreover, among the five markers located in the PrP region, only the three closest ones were affected. The evolution of the number of alleles, heterozygote deficiency within population, expected heterozygosity and the Reynolds distances agreed with the criteria from pedigree and pointed out that neutral genetic variability was not much affected. This trend depended on breed, i.e. on their initial states (population size, PrP frequencies and on the selection strategies for improving scrapie resistance while carrying out selection for production traits.

  2. Biological and biochemical characterization of mice expressing prion protein devoid of the octapeptide repeat region after infection with prions.

    Science.gov (United States)

    Yamaguchi, Yoshitaka; Miyata, Hironori; Uchiyama, Keiji; Ootsuyama, Akira; Inubushi, Sachiko; Mori, Tsuyoshi; Muramatsu, Naomi; Katamine, Shigeru; Sakaguchi, Suehiro

    2012-01-01

    Accumulating lines of evidence indicate that the N-terminal domain of prion protein (PrP) is involved in prion susceptibility in mice. In this study, to investigate the role of the octapeptide repeat (OR) region alone in the N-terminal domain for the susceptibility and pathogenesis of prion disease, we intracerebrally inoculated RML scrapie prions into tg(PrPΔOR)/Prnp(0/0) mice, which express mouse PrP missing only the OR region on the PrP-null background. Incubation times of these mice were not extended. Protease-resistant PrPΔOR, or PrP(Sc)ΔOR, was easily detectable but lower in the brains of these mice, compared to that in control wild-type mice. Consistently, prion titers were slightly lower and astrogliosis was milder in their brains. However, in their spinal cords, PrP(Sc)ΔOR and prion titers were abundant and astrogliosis was as strong as in control wild-type mice. These results indicate that the role of the OR region in prion susceptibility and pathogenesis of the disease is limited. We also found that the PrP(Sc)ΔOR, including the pre-OR residues 23-50, was unusually protease-resistant, indicating that deletion of the OR region could cause structural changes to the pre-OR region upon prion infection, leading to formation of a protease-resistant structure for the pre-OR region.

  3. A closer look at prion strains: characterization and important implications.

    Science.gov (United States)

    Solforosi, Laura; Milani, Michela; Mancini, Nicasio; Clementi, Massimo; Burioni, Roberto

    2013-01-01

    Prions are infectious proteins that are responsible for transmissible spongiform encephalopathies (TSEs) and consist primarily of scrapie prion protein (PrP (Sc) ), a pathogenic isoform of the host-encoded cellular prion protein (PrP (C) ). The absence of nucleic acids as essential components of the infectious prions is the most striking feature associated to these diseases. Additionally, different prion strains have been isolated from animal diseases despite the lack of DNA or RNA molecules. Mounting evidence suggests that prion-strain-specific features segregate with different PrP (Sc) conformational and aggregation states. Strains are of practical relevance in prion diseases as they can drastically differ in many aspects, such as incubation period, PrP (Sc) biochemical profile (e.g., electrophoretic mobility and glycoform ratio) and distribution of brain lesions. Importantly, such different features are maintained after inoculation of a prion strain into genetically identical hosts and are relatively stable across serial passages. This review focuses on the characterization of prion strains and on the wide range of important implications that the study of prion strains involves.

  4. Role of galectin-3 in prion infections of the CNS

    International Nuclear Information System (INIS)

    Mok, Simon W.F.; Riemer, Constanze; Madela, Kazimierz; Hsu, Daniel K.; Liu, Fu-Tong; Gueltner, Sandra; Heise, Ines; Baier, Michael

    2007-01-01

    Galectin-3 is a multi-functional protein and participates in mediating inflammatory reactions. The pronounced overexpression of galectin-3 in prion-infected brain tissue prompted us to study the role of this protein in a murine prion model. Immunofluorescence double-labelling identified microglia as the major cell type expressing galectin-3. Ablation of galectin-3 did not affect PrP Sc -deposition and development of gliosis. However, galectin-3 -/- -mice showed prolonged survival times upon intracerebral and peripheral scrapie infections. Moreover, protein levels of the lysosomal activation marker LAMP-2 were markedly reduced in prion-infected galectin-3 -/- -mice suggesting a role of galectin-3 in regulation of lysosomal functions. Lower mRNA levels of Beclin-1 and Atg5 in prion-infected wild-type and galectin-3 -/- -mice indicated an impairment of autophagy although autophagosome formation was unchanged. The results point towards a detrimental role of galectin-3 in prion infections of the CNS and suggest that endo-/lysosomal dysfunction in combination with reduced autophagy may contribute to disease development

  5. Prion protein degradation by lichens of the genus Cladonia

    Science.gov (United States)

    Bennett, James P.; Rodriguez, Cynthia M.; Johnson, Christopher J.

    2012-01-01

    It has recently been discovered that lichens contain a serine protease capable of degrading the pathogenic prion protein, the etiological agent of prion diseases such as sheep scrapie and cervid chronic wasting disease. Limited methods are available to degrade or inactivate prion disease agents, especially in the environment, and lichens or their serine protease could prove important for management of these diseases. Scant information is available regarding the presence or absence of the protease responsible for degrading prion protein (PrP) in lichen species and, in this study, we tested the hypothesis that PrP degradation activity in lichens is phylogenetically-based by testing 44 species of Cladonia lichens, a genus for which a significant portion of the phylogeny is well established. We categorized PrP degradation activity among the 44 species (high, moderate, low or none) and found that activity in Cladonia species did not correspond with phylogenetic position of the species. Degradation of PrP did correspond, however, with three classical taxonomic characters within the genus: species with brown apothecia, no usnic acid, and the presence of a cortex. Of the 44 species studied, 18 (41%) had either high or moderate PrP degradation activity, suggesting the protease may be frequent in this genus of lichens.

  6. Peroxiredoxin 6 promotes upregulation of the prion protein (PrP in neuronal cells of prion-infected mice

    Directory of Open Access Journals (Sweden)

    Wagner Wibke

    2012-12-01

    Full Text Available Abstract Background It has been widely established that the conversion of the cellular prion protein (PrPC into its abnormal isoform (PrPSc is responsible for the development of transmissible spongiform encephalopathies (TSEs. However, the knowledge of the detailed molecular mechanisms and direct functional consequences within the cell is rare. In this study, we aimed at the identification of deregulated proteins which might be involved in prion pathogenesis. Findings Apolipoprotein E and peroxiredoxin 6 (PRDX6 were identified as upregulated proteins in brains of scrapie-infected mice and cultured neuronal cell lines. Downregulation of PrP gene expression using specific siRNA did not result in a decrease of PRDX6 amounts. Interestingly, selective siRNA targeting PRDX6 or overexpression of PRDX6 controlled PrPC and PrPSc protein amounts in neuronal cells. Conclusions Besides its possible function as a novel marker protein in the diagnosis of TSEs, PDRX6 represents an attractive target molecule in putative pharmacological intervention strategies in the future.

  7. Inactivation of prion infectivity by ionizing rays

    Energy Technology Data Exchange (ETDEWEB)

    Gominet, M. [Ionisos, ZI les Chatinieres, F01120 Dagneux (France); Vadrot, C.; Austruy, G. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France); Darbord, J.C. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France)], E-mail: darbord@pharmacie.univ-paris5.fr

    2007-11-15

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination.

  8. Orally administered indomethacin acutely reduces cellular prion protein in the small intestine and modestly increases survival of mice exposed to infectious prions.

    Science.gov (United States)

    Martin, Gary R; Sharkey, Keith A; Jirik, Frank R

    2015-05-01

    The oral uptake of infectious prions represents a common way to acquire a prion disease; thus, host factors, such as gut inflammation and intestinal "leakiness", have the potential to influence infectivity. For example, the ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs) is known to induce intestinal inflammation and increase intestinal permeability. Previously, we reported that normal cellular prion protein (PrP(C)) expression was increased in experimental colitis, and since the level of PrP(C) expressed is a determinant of prion disease propagation, we hypothesized that NSAID administration prior to the oral inoculation of mice with infectious prions would increase intestinal PrP(C) expression and accelerate the onset of neurological disease. In the long-term experiments, one group of mice was gavaged with indomethacin, followed by a second gavage with brain homogenate containing mouse-adapted scrapie (ME7). Control mice received ME7 brain homogenate alone. Brain and splenic tissues were harvested at several time points for immunoblotting, including at the onset of clinical signs of disease. In a second series of experiments, mice were gavaged with indomethacin to assess the acute effects of this treatment on intestinal PrP(C) expression. Acutely, NSAID treatment reduced intestinal PrP(C) expression, and chronically, there was a modest delay in the onset of neurological disease. In contrast to our hypothesis, brief exposure to an NSAID decreased intestinal PrP(C) expression and led to a modest survival advantage following oral ingestion of infectious prions.

  9. Control of bovine spongiform encephalopathy by genetic engineering: possible approaches and regulatory considerations

    International Nuclear Information System (INIS)

    Gavora, J.S.; Kochhar, H.P.S.; Gifford, G.A.

    2005-01-01

    Transmissible spongiform encephalopathies (TSE) include bovine spongiform encephalopathy (BSE), scrapie in sheep and Creutzfeldt-Jakob disease (CJD) in humans. A new CJD variant (nvCJD) is believed to be related to consumption of meat from BSE cattle. In TSE individuals, prion proteins (PrP) with approximately 250 amino acids convert to the pathogenic prion PrP Sc , leading to a dysfunction of the central neural system. Research elsewhere with mice has indicated a possible genetic engineering approach to the introduction of BSE resistance: individuals with amino acid substitutions at positions 167 or 218, inoculated with a pathogenic prion protein, did not support PrP Sc replication. This raises the possibility of producing prion-resistant cattle with a single PrP amino acid substitution. Since prion-resistant animals might still harbour acquired prion infectivity, regulatory assessment of the engineered animals would need to ascertain that such possible 'carriers' do not result in a threat to animal and human health. (author)

  10. Reduction of prion infectivity in packed red blood cells

    International Nuclear Information System (INIS)

    Morales, Rodrigo; Buytaert-Hoefen, Kimberley A.; Gonzalez-Romero, Dennisse; Castilla, Joaquin; Hansen, Eric T.; Hlavinka, Dennis; Goodrich, Raymond P.; Soto, Claudio

    2008-01-01

    The link between a new variant form of Creutzfeldt-Jakob disease (vCJD) and the consumption of prion contaminated cattle meat as well as recent findings showing that vCJD can be transmitted by blood transfusion have raised public health concerns. Currently, a reliable test to identify prions in blood samples is not available. The purpose of this study was to evaluate the possibility to remove scrapie prion protein (PrP Sc ) and infectivity from red blood cell (RBC) suspensions by a simple washing procedure using a cell separation and washing device. The extent of prion removal was assessed by Western blot, PMCA and infectivity bioassays. Our results revealed a substantial removal of infectious prions (≥3 logs of infectivity) by all techniques used. These data suggest that a significant amount of infectivity present in RBC preparations can be removed by a simple washing procedure. This technology may lead to increased safety of blood products and reduce the risk of further propagation of prion diseases.

  11. Lichens: Unexpected anti-prion agents?

    Science.gov (United States)

    Rodriguez, Cynthia M.; Bennett, James P.; Johnson, Christopher J.

    2012-01-01

    The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents on the landscape. We have found that certain lichens, common, ubiquitous, symbiotic organisms, possess a serine protease capable of degrading prion protein (PrP) from prion-infected animals. The protease functions against a range of prion strains from various hosts and reduces levels of abnormal PrP by at least two logs. We have now tested more than 20 lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade PrP. Critical next steps include examining the effect of lichens on prion infectivity and cloning the protease responsible for PrP degradation. The impact of lichens on prions in the environment remains unknown. We speculate that lichens could have the potential to degrade prions when they are shed from infected animals onto lichens or into environments where lichens are abundant. In addition, lichens are frequently consumed by cervids and many other animals and the effect of dietary lichens on prion disease transmission should also be considered.

  12. Mutation directional selection sheds light on prion pathogenesis

    International Nuclear Information System (INIS)

    Shen, Liang; Ji, Hong-Fang

    2011-01-01

    Highlights: → Most pathogenic mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. → Mutation-induced changes may strengthen the interactions between PrP and facilitating factors. → The findings also have significant implications for exploring potential regions involved in the conformational transition from PrP C to PrP Sc . -- Abstract: As mutations in the PRNP gene account for human hereditary prion diseases (PrDs), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (PrP C ) to abnormal scrapie isoform (PrP Sc ). Many studies proposed that these pathogenic mutations may make PrP more susceptible to conformational change through altering its structure stability. By evaluating the most recent observations regarding pathogenic mutations, it was found that the pathogenic mutations do not exert a uniform effect on the thermodynamic stability of the human PrP's structure. Through analyzing the reported PrDs-related mutations, we found that 25 out of 27 mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. Based on the triggering role reported by previous studies of facilitating factors in PrP C conversion, e.g., lipid and polyanion, we proposed that the mutation-induced changes may strengthen the interaction between PrP and facilitating factors, which will accelerate PrP conversion and cause PrDs.

  13. Semi-purification procedures of prions from a prion-infected brain using sucrose has no influence on the nonenzymatic glycation of the disease-associated prion isoform.

    Science.gov (United States)

    Choi, Yeong-Gon; Kim, Jae-Il; Choi, Eun-Kyoung; Carp, Richard I; Kim, Yong-Sun

    2016-01-01

    Previous studies have shown that the Nε-carboxymethyl group is linked to not only one or more N-terminal Lys residues but also to one or more Lys residues of the protease-resistant core region of the pathogenic prion isoform (PrPSc) in prion-infected brains. Using an anti-advanced glycation end product (AGE) antibody, we detected nonenzymatically glycated PrPSc (AGE-PrPSc) in prion-infected brains following concentration by a series of ultracentrifugation steps with a sucrose cushion. In the present study, the levels of in vitro nonenzymatic glycation of PrPSc using sucrose were investigated to determine whether sucrose cushion can artificially and nonenzymatically induce in vitro glycation during ultracentrifugation. The first insoluble pellet fraction following the first ultracentrifugation (PU1st) collected from 263K scrapie-infected brains was incubated with sucrose, glucose or colloidal silica coated with polyvinylpyrrolidone (percoll). None of the compounds in vitro resulted in AGE-PrPSc. Nonetheless, glucose and percoll produced AGEs in vitro from other proteins within PU1st of the infected brains. This reaction could lead to the AGE-modified polymer(s) of nonenzymatic glycation-prone protein(s). This study showed that PrPSc is not nonenzymatically glycated in vitro with sucrose, glucose or percoll and that AGE-modified PrPSc can be isolated and enriched from prion-infected brains.

  14. Virus inactivation studies using ion beams, electron and gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Smolko, Eduardo E. [Laboratorio de Polimeros, Grupo Aplicaciones Industriales, Unidad de Aplicaciones Tecnologicas y Agropecuarias, Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Pbro. Juan Gonzalez y Aragon 15, C.P. B1802AYA Ezeiza, Buenos Aires (Argentina)]. E-mail: smolko@cae.cnea.gov.ar; Lombardo, Jorge H. [Biotech S.A., C.P. 1754 Buenos Aires (Argentina)

    2005-07-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle ({alpha}, d and ss) and {gamma} irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D{sub 37} dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

  15. Virus inactivation studies using ion beams, electron and gamma irradiation

    International Nuclear Information System (INIS)

    Smolko, Eduardo E.; Lombardo, Jorge H.

    2005-01-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle (α, d and ss) and γ irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D 37 dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule

  16. Instability of buried hydration sites increases protein subdomains fluctuations in the human prion protein by the pathogenic mutation T188R

    Science.gov (United States)

    Tomobe, Katsufumi; Yamamoto, Eiji; Akimoto, Takuma; Yasui, Masato; Yasuoka, Kenji

    2016-05-01

    The conformational change from the cellular prion protein (PrPc) to scrapie prion protein (PrPsc) is a key process in prion diseases. The prion protein has buried water molecules which significantly contribute to the stability of the protein; however, there has been no report investigating the influence on the buried hydration sites by a pathogenic mutation not adjacent to the buried hydration sites. Here, we perform molecular dynamics simulations of wild type (WT) PrPc and pathogenic point mutant T188R to investigate conformational changes and the buried hydration sites. In WT-PrPc, four buried hydration sites are identified by residence time and rotational relaxation analysis. However, there are no stable buried hydration sites in one of T188R simulations, which indicates that T188R sometimes makes the buried hydration sites fragile. We also find that fluctuations of subdomains S1-H1-S2 and H1-H2 increase in T188R when the buried hydration sites become unstable. Since the side chain of arginine which is replaced from threonine in T188R is larger than of threonine, the side chain cannot be embedded in the protein, which is one of the causes of the instability of subdomains. These results show correlations between the buried hydration sites and the mutation which is far from them, and provide a possible explanation for the instability by mutation.

  17. A closer look at prion strains

    Science.gov (United States)

    Solforosi, Laura; Milani, Michela; Mancini, Nicasio; Clementi, Massimo; Burioni, Roberto

    2013-01-01

    Prions are infectious proteins that are responsible for transmissible spongiform encephalopathies (TSEs) and consist primarily of scrapie prion protein (PrPSc), a pathogenic isoform of the host-encoded cellular prion protein (PrPC). The absence of nucleic acids as essential components of the infectious prions is the most striking feature associated to these diseases. Additionally, different prion strains have been isolated from animal diseases despite the lack of DNA or RNA molecules. Mounting evidence suggests that prion-strain-specific features segregate with different PrPSc conformational and aggregation states. Strains are of practical relevance in prion diseases as they can drastically differ in many aspects, such as incubation period, PrPSc biochemical profile (e.g., electrophoretic mobility and glycoform ratio) and distribution of brain lesions. Importantly, such different features are maintained after inoculation of a prion strain into genetically identical hosts and are relatively stable across serial passages. This review focuses on the characterization of prion strains and on the wide range of important implications that the study of prion strains involves. PMID:23357828

  18. Inactivation of prion infectivity by ionizing rays

    International Nuclear Information System (INIS)

    Gominet, M.; Vadrot, C.; Austruy, G.; Darbord, J.C.

    2007-01-01

    Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination

  19. Piperazine derivatives inhibit PrP/PrP(res) propagation in vitro and in vivo.

    Science.gov (United States)

    Leidel, Fabienne; Eiden, Martin; Geissen, Markus; Hirschberger, Thomas; Tavan, Paul; Giese, Armin; Kretzschmar, Hans A; Schätzl, Hermann; Groschup, Martin H

    2014-02-28

    Prion diseases are fatal neurodegenerative disorders, which are not curable and no effective treatment exists so far. The major neuropathological change in diseased brains is the conversion of the normal cellular form of the prion protein PrPc(C) into a disease-associated isoform PrP(Sc). PrP(Sc) accumulates into multimeres and fibrillar aggregates, which leads to the formation of amyloid plaques. Increasing evidence indicates a fundamental role of PrP(Sc) species and its aggregation in the pathogenesis of prion diseases, which initiates the pathological cascade and leads to neurodegeneration accompanied by spongiform changes. In search of compounds that have the potential to interfere with PrP(Sc) formation and propagation, we used a cell based assay for the screening of potential aggregation inhibitors. The assay deals with a permanently prion infected cell line that was adapted for a high-throughput screening of a compound library composed of 10,000 compounds (DIVERset 2, ChemBridge). We could detect six different classes of highly potent inhibitors of PrP(Sc) propagation in vitro and identified piperazine derivatives as a new inhibitory lead structure, which increased incubation time of scrapie infected mice. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Mother to offspring transmission of chronic wasting disease in reeves' muntjac deer.

    Directory of Open Access Journals (Sweden)

    Amy V Nalls

    Full Text Available The horizontal transmission of prion diseases has been well characterized in bovine spongiform encephalopathy (BSE, chronic wasting disease (CWD of deer and elk and scrapie of sheep, and has been regarded as the primary mode of transmission. Few studies have monitored the possibility of vertical transmission occurring within an infected mother during pregnancy. To study the potential for and pathway of vertical transmission of CWD in the native cervid species, we used a small cervid model-the polyestrous breeding, indoor maintainable, Reeves' muntjac deer-and determined that the susceptibility and pathogenesis of CWD in these deer reproduce that in native mule and white-tailed deer. Moreover, we demonstrate here that CWD prions are transmitted from doe to fawn. Maternal CWD infection also appears to result in lower percentage of live birth offspring. In addition, evolving evidence from protein misfolding cyclic amplification (PMCA assays on fetal tissues suggest that covert prion infection occurs in utero. Overall, our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.

  1. PrPSc detection in formalin-fixed paraffin-embedded tissue by ELISA

    Directory of Open Access Journals (Sweden)

    Nicholson Eric M

    2011-10-01

    Full Text Available Abstract Background Formalin-fixed paraffin-embedded tissue is regularly employed in the diagnosis of transmissible spongiform encephalopathies (TSE by immunohistochemistry (IHC, the standard by which all other TSE diagnostic protocols are judged. While IHC affords advantages over diagnostic approaches that typically utilize fresh or frozen tissue, such as Western blot and ELISA, the process of fixing, staining, and analyzing individual sections by hand does not allow for rapid or high throughput screening. However, preservation of tissues in formalin is not dependent upon the availability of refrigeration. Findings Formalin-fixed paraffin-embedded tissues from TSE transmission studies of scrapie in sheep, chronic wasting disease in white-tailed deer or transmissible mink encephalopathy in cattle were cut at 5 μm thickness. Samples containing the tissue equivalent of as little as one 5 μm section can be used to readily discriminate positive from negative samples. Conclusions This approach cannot replace IHC but may be used along with IHC as both a more rapid and readily high throughput screen where fresh or frozen tissues are not available or impractical.

  2. The prion-ZIP connection: From cousins to partners in iron uptake

    Science.gov (United States)

    Singh, Neena; Asthana, Abhishek; Baksi, Shounak; Desai, Vilok; Haldar, Swati; Hari, Sahi; Tripathi, Ajai K

    2015-01-01

    ABSTRACT Converging observations from disparate lines of inquiry are beginning to clarify the cause of brain iron dyshomeostasis in sporadic Creutzfeldt-Jakob disease (sCJD), a neurodegenerative condition associated with the conversion of prion protein (PrPC), a plasma membrane glycoprotein, from α-helical to a β-sheet rich PrP-scrapie (PrPSc) isoform. Biochemical evidence indicates that PrPC facilitates cellular iron uptake by functioning as a membrane-bound ferrireductase (FR), an activity necessary for the transport of iron across biological membranes through metal transporters. An entirely different experimental approach reveals an evolutionary link between PrPC and the Zrt, Irt-like protein (ZIP) family, a group of proteins involved in the transport of zinc, iron, and manganese across the plasma membrane. Close physical proximity of PrPC with certain members of the ZIP family on the plasma membrane and increased uptake of extracellular iron by cells that co-express PrPC and ZIP14 suggest that PrPC functions as a FR partner for certain members of this family. The connection between PrPC and ZIP proteins therefore extends beyond common ancestry to that of functional cooperation. Here, we summarize evidence supporting the facilitative role of PrPC in cellular iron uptake, and implications of this activity on iron metabolism in sCJD brains. PMID:26689487

  3. The Role of Unfolded Protein Response and Mitogen-Activated Protein Kinase Signaling in Neurodegenerative Diseases with Special Focus on Prion Diseases

    Directory of Open Access Journals (Sweden)

    Lifeng Yang

    2017-05-01

    Full Text Available Prion diseases are neurodegenerative pathologies characterized by the accumulation of a protease-resistant form of the cellular prion protein named prion protein scrapie (PrPSc in the brain. PrPSc accumulation in the endoplasmic reticulum (ER result in a dysregulated calcium (Ca2+ homeostasis and subsequent initiation of unfolded protein response (UPR leading to neuronal dysfunction and apoptosis. The molecular mechanisms for the transition between adaptation to ER stress and ER stress-induced apoptosis are still unclear. Mitogen-activated protein kinases (MAPKs are serine/threonine protein kinases that rule the signaling of many extracellular stimuli from plasma membrane to the nucleus. However the identification of numerous points of cross talk between the UPR and MAPK signaling pathways may contribute to our understanding of the consequences of ER stress in prion diseases. Indeed the MAPK signaling network is known to regulate cell cycle progression and cell survival or death responses following a variety of stresses including misfolded protein response stress. In this article, we review the UPR signaling in prion diseases and discuss the triad of MAPK signaling pathways. We also describe the role played by MAPK signaling cascades in Alzheimer’s (AD and Parkinson’s disease (PD. We will also overview the mechanisms of cell death and the role of MAPK signaling in prion disease progression and highlight potential avenues for therapeutic intervention.

  4. Instability of buried hydration sites increases protein subdomains fluctuations in the human prion protein by the pathogenic mutation T188R

    Directory of Open Access Journals (Sweden)

    Katsufumi Tomobe

    2016-05-01

    Full Text Available The conformational change from the cellular prion protein (PrPc to scrapie prion protein (PrPsc is a key process in prion diseases. The prion protein has buried water molecules which significantly contribute to the stability of the protein; however, there has been no report investigating the influence on the buried hydration sites by a pathogenic mutation not adjacent to the buried hydration sites. Here, we perform molecular dynamics simulations of wild type (WT PrPc and pathogenic point mutant T188R to investigate conformational changes and the buried hydration sites. In WT-PrPc, four buried hydration sites are identified by residence time and rotational relaxation analysis. However, there are no stable buried hydration sites in one of T188R simulations, which indicates that T188R sometimes makes the buried hydration sites fragile. We also find that fluctuations of subdomains S1-H1-S2 and H1-H2 increase in T188R when the buried hydration sites become unstable. Since the side chain of arginine which is replaced from threonine in T188R is larger than of threonine, the side chain cannot be embedded in the protein, which is one of the causes of the instability of subdomains. These results show correlations between the buried hydration sites and the mutation which is far from them, and provide a possible explanation for the instability by mutation.

  5. Pathogenesis of bovine spongiform encephalopathy in sheep.

    Science.gov (United States)

    van Keulen, L J M; Vromans, M E W; Dolstra, C H; Bossers, A; van Zijderveld, F G

    2008-01-01

    The pathogenesis of bovine spongiform encephalopathy (BSE) in sheep was studied by immunohistochemical detection of scrapie-associated prion protein (PrP(Sc)) in the gastrointestinal, lymphoid and neural tissues following oral inoculation with BSE brain homogenate. First accumulation of PrP(Sc) was detected after 6 months in the tonsil and the ileal Peyer's patches. At 9 months postinfection, PrP(Sc) accumulation involved all gut-associated lymphoid tissues and lymph nodes as well as the spleen. At this time point, PrP(Sc) accumulation in the peripheral neural tissues was first seen in the enteric nervous system of the caudal jejunum and ileum and in the coeliac-mesenteric ganglion. In the central nervous system, PrP(Sc) was first detected in the dorsal motor nucleus of the nervus Vagus in the medulla oblongata and in the intermediolateral column in the spinal cord segments T7-L1. At subsequent time points, PrP(Sc) was seen to spread within the lymphoid system to also involve all non-gut-associated lymphoid tissues. In the enteric nervous system, further spread of PrP(Sc) involved the neural plexi along the entire gastrointestinal tract and in the CNS the complete neuraxis. These findings indicate a spread of the BSE agent in sheep from the enteric nervous system through parasympathetic and sympathetic nerves to the medulla oblongata and the spinal cord.

  6. Resistance of Soil-Bound Prions to Rumen Digestion

    Science.gov (United States)

    Saunders, Samuel E.; Bartelt-Hunt, Shannon L.; Bartz, Jason C.

    2012-01-01

    Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrPc from complete digestion, while both unbound and soil-bound infectious PrPSc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment. PMID:22937149

  7. NF EN ISO 11137-1, July 2006. Sterilization of health care products - Irradiation - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices

    International Nuclear Information System (INIS)

    2006-01-01

    This part of the ISO 11137 standard specifies requirements for the development, validation and routine control of a radiation sterilization process for medical devices. Although the scope of this part of the ISO 11137 standard is limited to medical devices, it specifies requirements and provides guidance that may be applicable to other products and equipment. This part of the international standard covers radiation processes employing irradiators using the radionuclide 60 Co or 137 Cs, a beam from an electron generator or a beam from an X-ray generator. This part of the international standard does not: - specify requirements for development, validation and routine control of a process for inactivating the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease; - detail specified requirements for designating a medical device as sterile; - specify a quality management system for the control of all stages of production of medical devices; - specify requirements for occupational safety associated with the design and operation of irradiation facilities; - specify requirements for the sterilization of used or reprocessed devices

  8. Regulation of human cerebrospinal fluid malate dehydrogenase 1 in sporadic Creutzfeldt-Jakob disease patients.

    Science.gov (United States)

    Schmitz, Matthias; Llorens, Franc; Pracht, Alexander; Thom, Tobias; Correia, Ângela; Zafar, Saima; Ferrer, Isidre; Zerr, Inga

    2016-11-14

    The identification of reliable diagnostic biomarkers in differential diagnosis of neurodegenerative diseases is an ongoing topic. A previous two-dimensional proteomic study on cerebrospinal fluid (CSF) revealed an elevated level of an enzyme, mitochondrial malate dehydrogenase 1 (MDH1), in sporadic Creutzfeldt-Jakob disease (sCJD) patients. Here, we could demonstrate the expression of MDH1 in neurons as well as in the neuropil. Its levels are lower in sCJD brains than in control brains. An examination of CSF-MDH1 in sCJD patients by ELISA revealed a significant elevation of CSF-MDH1 levels in sCJD patients (independently from the PRNP codon 129 MV genotype or the prion protein scrapie (PrP Sc ) type) in comparison to controls. In combination with total tau (tau), CSF-MDH1 detection exhibited a high diagnostic accuracy for sCJD diagnosis with a sensitivity of 97.5% and a specificity of 95.6%. A correlation study of MDH1 level in CSF with other neurodegenerative marker proteins revealed a significant positive correlation between MDH1 concentration with tau, 14-3-3 and neuron specific enolase level. In conclusion, our study indicated the potential of MDH1 in combination with tau as an additional biomarker in sCJD improving diagnostic accuracy of tau markedly.

  9. Sporadic Creutzfeldt-Jakob disease in a native Puerto Rican patient.

    Science.gov (United States)

    Del Pilar-Morales, Esteban A; Cali, Ignazio; Chapas, Javier; Bertrán-Pasarell, Jorge; Puoti, Gianfranco; Gambetti, Pierluigi; Nobo, Ulises

    2015-03-01

    The diagnosis of Creutzfeldt-Jakob disease (CJD) is often a challenge for most physicians given its extremely low incidence and different clinico-pathological presentations. We report the case of a 56-year old patient native to Puerto Rico suspected of sporadic Creutzfeldt-Jakob disease (sCD). The symptoms at onset were notorious for bilateral cortical blindness followed by rapidly progressive cognitive decline, visual deficit, increased levels of CSF 14-3-3 and tau along with positive brain MRI and EEG, are highly indicative of CJD. The definite diagnosis was confirmed by the National Prion Disease Pathology Surveillance Center (NPDPSC), in Cleveland, Ohio, USA. Lack of genetic mutations in the prion protein (PrP) gene, widespread histopathological changes and the accumulation of scrapie PrP (PrPSc) in the brain confirmed the diagnosis of sCJD. The patient, admitted to our institution in 2011, represents the first detailed report of sCJD in a native Puerto Rican patient living in Puerto Rico.

  10. Sod1 deficiency reduces incubation time in mouse models of prion disease.

    Directory of Open Access Journals (Sweden)

    Shaheen Akhtar

    Full Text Available Prion infections, causing neurodegenerative conditions such as Creutzfeldt-Jakob disease and kuru in humans, scrapie in sheep and BSE in cattle are characterised by prolonged and variable incubation periods that are faithfully reproduced in mouse models. Incubation time is partly determined by genetic factors including polymorphisms in the prion protein gene. Quantitative trait loci studies in mice and human genome-wide association studies have confirmed that multiple genes are involved. Candidate gene approaches have also been used and identified App, Il1-r1 and Sod1 as affecting incubation times. In this study we looked for an association between App, Il1-r1 and Sod1 representative SNPs and prion disease incubation time in the Northport heterogeneous stock of mice inoculated with the Chandler/RML prion strain. No association was seen with App, however, significant associations were seen with Il1-r1 (P = 0.02 and Sod1 (P<0.0001 suggesting that polymorphisms at these loci contribute to the natural variation observed in incubation time. Furthermore, following challenge with Chandler/RML, ME7 and MRC2 prion strains, Sod1 deficient mice showed highly significant reductions in incubation time of 20, 13 and 24%, respectively. No differences were detected in Sod1 expression or activity. Our data confirm the protective role of endogenous Sod1 in prion disease.

  11. NF EN ISO 11137-1, July 2006. Sterilization of health care products - Irradiation - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices; NF EN ISO 11137-1, Juillet 2006. Sterilisation des produits de sante - Irradiation - Partie 1: exigences relatives a la mise au point, a la validation et au controle de routine d'un procede de sterilisation pour les dispositifs medicaux

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This part of the ISO 11137 standard specifies requirements for the development, validation and routine control of a radiation sterilization process for medical devices. Although the scope of this part of the ISO 11137 standard is limited to medical devices, it specifies requirements and provides guidance that may be applicable to other products and equipment. This part of the international standard covers radiation processes employing irradiators using the radionuclide {sup 60}Co or {sup 137}Cs, a beam from an electron generator or a beam from an X-ray generator. This part of the international standard does not: - specify requirements for development, validation and routine control of a process for inactivating the causative agents of spongiform encephalopathies such as scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease; - detail specified requirements for designating a medical device as sterile; - specify a quality management system for the control of all stages of production of medical devices; - specify requirements for occupational safety associated with the design and operation of irradiation facilities; - specify requirements for the sterilization of used or reprocessed devices.

  12. Generation of a persistently infected MDBK cell line with natural bovine spongiform encephalopathy (BSE.

    Directory of Open Access Journals (Sweden)

    Dongseob Tark

    Full Text Available Bovine spongiform encephalopathy (BSE is a zoonotic transmissible spongiform encephalopathy (TSE thought to be caused by the same prion strain as variant Creutzfeldt-Jakob disease (vCJD. Unlike scrapie and chronic wasting disease there is no cell culture model allowing the replication of proteinase K resistant BSE (PrPBSE and the further in vitro study of this disease. We have generated a cell line based on the Madin-Darby Bovine Kidney (MDBK cell line over-expressing the bovine prion protein. After exposure to naturally BSE-infected bovine brain homogenate this cell line has shown to replicate and accumulate PrPBSE and maintain infection up to passage 83 after initial challenge. Collectively, we demonstrate, for the first time, that the BSE agent can infect cell lines over-expressing the bovine prion protein similar to other prion diseases. These BSE infected cells will provide a useful tool to facilitate the study of potential therapeutic agents and the diagnosis of BSE.

  13. Amyloid Structure and Assembly: Insights from Scanning Transmission Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Goldsbury, C.; Wall, J.; Baxa, U.; Simon, M. N.; Steven, A. C.; Engel, A.; Aebi, U.; Muller, S. A.

    2011-01-01

    Amyloid fibrils are filamentous protein aggregates implicated in several common diseases such as Alzheimer's disease and type II diabetes. Similar structures are also the molecular principle of the infectious spongiform encephalopathies such as Creutzfeldt-Jakob disease in humans, scrapie in sheep, and of the so-called yeast prions, inherited non-chromosomal elements found in yeast and fungi. Scanning transmission electron microscopy (STEM) is often used to delineate the assembly mechanism and structural properties of amyloid aggregates. In this review we consider specifically contributions and limitations of STEM for the investigation of amyloid assembly pathways, fibril polymorphisms and structural models of amyloid fibrils. This type of microscopy provides the only method to directly measure the mass-per-length (MPL) of individual filaments. Made on both in vitro assembled and ex vivo samples, STEM mass measurements have illuminated the hierarchical relationships between amyloid fibrils and revealed that polymorphic fibrils and various globular oligomers can assemble simultaneously from a single polypeptide. The MPLs also impose strong constraints on possible packing schemes, assisting in molecular model building when combined with high-resolution methods like solid-state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR).

  14. Insights into alternative prion protein topologies induced under high hydrostatic pressure

    International Nuclear Information System (INIS)

    Torrent, Joan; Alvarez-Martinez, Maria Teresa; Heitz, Frederic; Liautard, Jean-Pierre; Balny, Claude; Lange, Reinhard

    2004-01-01

    The critical step in the pathogenesis of transmissible spongiform encephalopathies (TSEs) appears to be a conformational transition of a normal prion protein (PrP C ) into a misfolded isoform (PrP Sc ). To gain insight into the structural conversion of the prion protein we have exploited the use of high hydrostatic pressure combined with various spectroscopic techniques. In vitro transitions of the recombinant PrP to a scrapie-like form have never resulted in an infectious structure. It is our hypothesis that the acquisition of the disease-causing conformation depends on folding pathways which are difficult to attain. We attempt to favour, via specific reaction conditions at high pressure, alternative routes of misfolding leading to a stable infectious amyloidogenic conformer. Our results have demonstrated the potential of high pressure to reveal various prion structural changes, which are inaccessible by conventional methods. Especially, we have characterized a pressure-induced conformer in which the normal α-helical structure is changed into a highly aggregated β-sheet conformation showing markedly increased resistance to proteolysis (key markers of potential infectious agents). Our work may have important implications, not only for ultimately proving the protein-only hypothesis and for understanding the basic mechanism of the disease, but also for developing preventative and therapeutic measures

  15. Lichens

    Science.gov (United States)

    Rodriguez, Cynthia M; Bennett, James P

    2012-01-01

    The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents on the landscape. We have found that certain lichens, common, ubiquitous, symbiotic organisms, possess a serine protease capable of degrading prion protein (PrP) from prion-infected animals. The protease functions against a range of prion strains from various hosts and reduces levels of abnormal PrP by at least two logs. We have now tested more than twenty lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade PrP. Critical next steps include examining the effect of lichens on prion infectivity and cloning the protease responsible for PrP degradation. The impact of lichens on prions in the environment remains unknown. We speculate that lichens could have the potential to degrade prions when they are shed from infected animals onto lichens or into environments where lichens are abundant. In addition, lichens are frequently consumed by cervids and many other animals and the effect of dietary lichens on prion disease transmission should also be considered. PMID:22453171

  16. Analysis of nucleic acid chaperoning by the prion protein and its inhibition by oligonucleotides.

    Science.gov (United States)

    Guichard, Cécile; Ivanyi-Nagy, Roland; Sharma, Kamal Kant; Gabus, Caroline; Marc, Daniel; Mély, Yves; Darlix, Jean-Luc

    2011-10-01

    Prion diseases are unique neurodegenerative illnesses associated with the conversion of the cellular prion protein (PrP(C)) into the aggregated misfolded scrapie isoform, named PrP(Sc). Recent studies on the physiological role of PrP(C) revealed that this protein has probably multiple functions, notably in cell-cell adhesion and signal transduction, and in assisting nucleic acid folding. In fact, in vitro findings indicated that the human PrP (huPrP) possesses nucleic acid binding and annealing activities, similarly to nucleic acid chaperone proteins that play essential roles in cellular DNA and RNA metabolism. Here, we show that a peptide, representing the N-terminal domain of huPrP, facilitates nucleic acid annealing by two parallel pathways nucleated through the stem termini. We also show that PrP of human or ovine origin facilitates DNA strand exchange, ribozyme-directed cleavage of an RNA template and RNA trans-splicing in a manner similar to the nucleocapsid protein of HIV-1. In an attempt to characterize inhibitors of PrP-chaperoning in vitro we discovered that the thioaptamer 5'-GACACAAGCCGA-3' was extensively inhibiting the PrP chaperoning activities. At the same time a recently characterized methylated oligoribonucleotide inhibiting the chaperoning activity of the HIV-1 nucleocapsid protein was poorly impairing the PrP chaperoning activities.

  17. The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1.

    Science.gov (United States)

    Gabus, C; Derrington, E; Leblanc, P; Chnaiderman, J; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W K; Marc, D; Nandi, P; Darlix, J L

    2001-06-01

    Transmissible spongiform encephalopathies are fatal neurodegenerative diseases associated with the accumulation of a protease-resistant form of the prion protein (PrP). Although PrP is conserved in vertebrates, its function remains to be identified. In vitro PrP binds large nucleic acids causing the formation of nucleoprotein complexes resembling human immunodeficiency virus type 1 (HIV-1) nucleocapsid-RNA complexes and in vivo MuLV replication accelerates the scrapie infectious process, suggesting possible interactions between retroviruses and PrP. Retroviruses, including HIV-1 encode a major nucleic acid binding protein (NC protein) found within the virus where 2000 NC protein molecules coat the dimeric genome. NC is required in virus assembly and infection to chaperone RNA dimerization and packaging and in proviral DNA synthesis by reverse transcriptase (RT). In HIV-1, 5'-leader RNA/NC interactions appear to control these viral processes. This prompted us to compare and contrast the interactions of human and ovine PrP and HIV-1 NCp7 with HIV-1 5'-leader RNA. Results show that PrP has properties characteristic of NCp7 with respect to viral RNA dimerization and proviral DNA synthesis by RT. The NC-like properties of huPrP map to the N-terminal region of huPrP. Interestingly, PrP localizes in the membrane and cytoplasm of PrP-expressing cells. These findings suggest that PrP is a multifunctional protein possibly participating in nucleic acid metabolism.

  18. Conceptual Incongruence between Prion Disease and Genetic Diversity in Ovine Species within European Union defined by Informational Statistics Terms

    Directory of Open Access Journals (Sweden)

    Gheorghe Hrinca

    2016-11-01

    Full Text Available Biodiversity and the studies of spongiform encephalopathies in the farm animals are highly topical concerns of the contemporary scientific world. Both themes are very interesting for the life sciences and very important for the application field of animal breeding. The implementation of these two concepts creates an antithetical paradigm: the achievement of genetic prophylaxis joins with the decrease of genetic diversity. The paper examines the genetic diversity and its evolution in sheep livestock from the European space in the context in which the European Community has developed very laborious and costly programs targeted both for conservation and enhancement of biodiversity and to eradicate the scrapie in small ruminants. This paper utilises a precise method to quantify the genetic biodiversity in all sheep populations in Europe by a modern concept derived from informational statistics - informational energy. In addition, the paper proposes concrete and viable solutions to achieve these two desiderata at optimal levels in connection with a perfect perspicacity of sheep breeder which consists in accuracy of the reproduction process and correct application of the selection criteria.

  19. Immunophenotype of cells within cervine rectoanal mucosa-associated lymphoid tissue and mesenteric lymph nodes.

    Science.gov (United States)

    Dagleish, M P; Finlayson, J; Steele, P J; Pang, Y; Hamilton, S; Eaton, S L; Sales, J; González, L; Chianini, F

    2012-05-01

    Rectoanal mucosa-associated lymphoid tissue (RAMALT) is a part of the lymphoid system that can be sampled easily in live animals, especially ruminants. RAMALT biopsy is useful for the diagnosis of transmissible spongiform encephalopathies, including scrapie in sheep and goats and chronic wasting disease (CWD) in cervids. Diagnosis is reliant on detection of abnormal prion protein (PrP(d)), which is associated with lymphoid follicles. For enzyme linked immunosorbent assays (ELISAs) detecting PrP(d) it is necessary to ensure that lymphoid follicles are present in biopsy samples to avoid false-negative results. Monoclonal antibodies known to recognize specific immune cell subsets present in lymphoid tissues of sheep were tested for cross-reactivity with cervine RAMALT and mesenteric lymph nodes (MLNs) preserved in zinc salts fixative. The distribution of cells expressing CD3, CD4, CD79, CD21 and class II molecules of the major histocompatibility complex was determined in these tissues. Cells of each immunophenotype had similar distributions in RAMALT and MLNs and these distributions were similar to those reported previously for sheep and cattle. The identification and validation of cervine lymphoid follicle cell markers (CD79 and CD21) may allow reduction in false-negative results during diagnosis of CWD by ELISA. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Mitigation of Prion Infectivity and Conversion Capacity by a Simulated Natural Process—Repeated Cycles of Drying and Wetting

    Science.gov (United States)

    Yuan, Qi; Eckland, Thomas; Telling, Glenn; Bartz, Jason; Bartelt-Hunt, Shannon

    2015-01-01

    Prions enter the environment from infected hosts, bind to a wide range of soil and soil minerals, and remain highly infectious. Environmental sources of prions almost certainly contribute to the transmission of chronic wasting disease in cervids and scrapie in sheep and goats. While much is known about the introduction of prions into the environment and their interaction with soil, relatively little is known about prion degradation and inactivation by natural environmental processes. In this study, we examined the effect of repeated cycles of drying and wetting on prion fitness and determined that 10 cycles of repeated drying and wetting could reduce PrPSc abundance, PMCA amplification efficiency and extend the incubation period of disease. Importantly, prions bound to soil were more susceptible to inactivation by repeated cycles of drying and wetting compared to unbound prions, a result which may be due to conformational changes in soil-bound PrPSc or consolidation of the bonding between PrPSc and soil. This novel finding demonstrates that naturally-occurring environmental process can degrade prions. PMID:25665187

  1. Insights into alternative prion protein topologies induced under high hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Torrent, Joan [INSERM U128, IFR 122, 1919 Route de Mende, F-34293 Montpellier cedex 5 (France); Alvarez-Martinez, Maria Teresa [INSERM U431, IFR 122, Place Eugene Bataillon, F-34095 Montpellier cedex 5 (France); Heitz, Frederic [CRBM, CNRS-UPR 1086, IFR 122, 1919 Route de Mende, F-34293 Montpellier cedex 5 (France); Liautard, Jean-Pierre [INSERM U431, IFR 122, Place Eugene Bataillon, F-34095 Montpellier cedex 5 (France); Balny, Claude [INSERM U128, IFR 122, 1919 Route de Mende, F-34293 Montpellier cedex 5 (France); Lange, Reinhard [INSERM U128, IFR 122, 1919 Route de Mende, F-34293 Montpellier cedex 5 (France)

    2004-04-14

    The critical step in the pathogenesis of transmissible spongiform encephalopathies (TSEs) appears to be a conformational transition of a normal prion protein (PrP{sup C}) into a misfolded isoform (PrP{sup Sc}). To gain insight into the structural conversion of the prion protein we have exploited the use of high hydrostatic pressure combined with various spectroscopic techniques. In vitro transitions of the recombinant PrP to a scrapie-like form have never resulted in an infectious structure. It is our hypothesis that the acquisition of the disease-causing conformation depends on folding pathways which are difficult to attain. We attempt to favour, via specific reaction conditions at high pressure, alternative routes of misfolding leading to a stable infectious amyloidogenic conformer. Our results have demonstrated the potential of high pressure to reveal various prion structural changes, which are inaccessible by conventional methods. Especially, we have characterized a pressure-induced conformer in which the normal {alpha}-helical structure is changed into a highly aggregated {beta}-sheet conformation showing markedly increased resistance to proteolysis (key markers of potential infectious agents). Our work may have important implications, not only for ultimately proving the protein-only hypothesis and for understanding the basic mechanism of the disease, but also for developing preventative and therapeutic measures.

  2. Immunohistochemical study of PrPSc distribution in neural and extraneural tissues of two cats with feline spongiform encephalopathy

    Directory of Open Access Journals (Sweden)

    Wunderlin Sabina S

    2009-03-01

    Full Text Available Abstract Background Two domestic shorthair cats presenting with progressive hind-limb ataxia and increased aggressiveness were necropsied and a post mortem diagnosis of Feline Spongiform Encephalopathy (FSE was made. A wide spectrum of tissue samples was collected and evaluated histologically and immunohistologically for the presence of PrPSc. Results Histopathological examination revealed a diffuse vacuolation of the grey matter neuropil with the following areas being most severely affected: corpus geniculatum medialis, thalamus, gyrus dentatus of the hippocampus, corpus striatum, and deep layers of the cerebral and cerebellar cortex as well as in the brain stem. In addition, a diffuse glial reaction involving astrocytes and microglia and intraneuronal vacuolation in a few neurons in the brain stem was present. Heavy PrPSc immunostaining was detected in brain, retina, optic nerve, pars nervosa of the pituitary gland, trigeminal ganglia and small amounts in the myenteric plexus of the small intestine (duodenum, jejunum and slightly in the medulla of the adrenal gland. Conclusion The PrPSc distribution within the brain was consistent with that described in other FSE-affected cats. The pattern of abnormal PrP in the retina corresponded to that found in a captive cheetah with FSE, in sheep with scrapie and was similar to nvCJD in humans.

  3. PrPC from stem cells to cancer

    Directory of Open Access Journals (Sweden)

    Séverine eMartin-Lannerée

    2014-09-01

    Full Text Available The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knock-out animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumours. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumour-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression.

  4. PrPc Does Not Mediate Internalization of PrPSc but Is Required at an Early Stage for De Novo Prion Infection of Rov Cells▿

    Science.gov (United States)

    Paquet, Sophie; Daude, Nathalie; Courageot, Marie-Pierre; Chapuis, Jérôme; Laude, Hubert; Vilette, Didier

    2007-01-01

    We have studied the interactions of exogenous prions with an epithelial cell line inducibly expressing PrPc protein and permissive to infection by a sheep scrapie agent. We demonstrate that abnormal PrP (PrPSc) and prion infectivity are efficiently internalized in Rov cells, whether or not PrPc is expressed. At odds with earlier studies implicating cellular heparan sulfates in PrPSc internalization, we failed to find any involvement of such molecules in Rov cells, indicating that prions can enter target cells by several routes. We further show that PrPSc taken up in the absence of PrPc was unable to promote efficient prion multiplication once PrPc expression was restored in the cells. This observation argues that interaction of PrPSc with PrPc has to occur early, in a specific subcellular compartment(s), and is consistent with the view that the first prion multiplication events may occur at the cell surface. PMID:17626095

  5. Translation of the prion protein mRNA is robust in astrocytes but does not amplify during reactive astrocytosis in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Walker S Jackson

    Full Text Available Prion diseases induce neurodegeneration in specific brain areas for undetermined reasons. A thorough understanding of the localization of the disease-causing molecule, the prion protein (PrP, could inform on this issue but previous studies have generated conflicting conclusions. One of the more intriguing disagreements is whether PrP is synthesized by astrocytes. We developed a knock-in reporter mouse line in which the coding sequence of the PrP expressing gene (Prnp, was replaced with that for green fluorescent protein (GFP. Native GFP fluorescence intensity varied between and within brain regions. GFP was present in astrocytes but did not increase during reactive gliosis induced by scrapie prion infection. Therefore, reactive gliosis associated with prion diseases does not cause an acceleration of local PrP production. In addition to aiding in Prnp gene activity studies, this reporter mouse line will likely prove useful for analysis of chimeric animals produced by stem cell and tissue transplantation experiments.

  6. α-Synuclein Amyloids Hijack Prion Protein to Gain Cell Entry, Facilitate Cell-to-Cell Spreading and Block Prion Replication.

    Science.gov (United States)

    Aulić, Suzana; Masperone, Lara; Narkiewicz, Joanna; Isopi, Elisa; Bistaffa, Edoardo; Ambrosetti, Elena; Pastore, Beatrice; De Cecco, Elena; Scaini, Denis; Zago, Paola; Moda, Fabio; Tagliavini, Fabrizio; Legname, Giuseppe

    2017-08-30

    The precise molecular mechanism of how misfolded α-synuclein (α-Syn) accumulates and spreads in synucleinopathies is still unknown. Here, we show the role of the cellular prion protein (PrP C ) in mediating the uptake and the spread of recombinant α-Syn amyloids. The in vitro data revealed that the presence of PrP C fosters the higher uptake of α-Syn amyloid fibrils, which was also confirmed in vivo in wild type (Prnp +/+ ) compared to PrP knock-out (Prnp -/- ) mice. Additionally, the presence of α-Syn amyloids blocked the replication of scrapie prions (PrP Sc ) in vitro and ex vivo, indicating a link between the two proteins. Indeed, whilst PrP C is mediating the internalization of α-Syn amyloids, PrP Sc is not able to replicate in their presence. This observation has pathological relevance, since several reported case studies show that the accumulation of α-Syn amyloid deposits in Creutzfeldt-Jakob disease patients is accompanied by a longer disease course.

  7. Encefalopatías espongiformes transmisibles: enfermedad crónica desgastante

    Directory of Open Access Journals (Sweden)

    M. A. Reyes-López

    2006-01-01

    Full Text Available Las enfermedades por encefalopatías espongiformes transmisibles (EET, algunas veces llamadas enfermedades “por priones”, son un grupo de enfermedades raras, incurables, neurodegenerativas y fatales, las cuales afectan a una variedad de mamíferos. En los pasados 20 años, las EET pasaron de ser “las enfermedades de fascinación” a enfermedades difíciles de entender, causantes de pérdidas económicas en el sector ganadero, además de provocar problemas de salud humana. Las EET incluyen Creutzfeldt-Jakob (CJD y kuru en humanos; scrapi en ovejas, encefalopatía en visón (TME y caquexia crónica del ciervo y alce (CWD. En el ganado, se propuso de manera sugestiva el nombre de “vacas locas” o encefalopatía espongiforme bovina (BSE. La CWD puede ser transmitida indirectamente a animales susceptibles a través de ambientes contaminados, mediante heces o cadáveres descompuestos. En los últimos 5 años, la distribución conocida de CWD en Norte América se extendió, incrementando las dudas sobre el impacto de esta enfermedad en cérvidos de vida libre y la viabilidad de ranchos cinegéticos. En México, no existe evidencia de CWD en venados de vida silvestre o cautiverio, aunque se ha detectado en un condado fronterizo de Nuevo México, EUA. La CWD es considerada una enfermedad exótica y deben de tomarse las medidas pertinentes para evitar su introducción en México.

  8. Methamphetamine increases Prion Protein and induces dopamine-dependent expression of protease resistant PrPsc.

    Science.gov (United States)

    Ferrucci, M; Ryskalin, L; Biagioni, F; Gambardella, S; Busceti, C L; Falleni, A; Lazzeri, G; Fornai, F

    2017-07-01

    The cellular prion protein (PrPc) is physiologically expressed within selective brain areas of mammals. Alterations in the secondary structure of this protein lead to scrapie-like prion protein (PrPsc), which precipitates in the cell. PrPsc has been detected in infectious, inherited or sporadic neurodegenerative disorders. Prion protein metabolism is dependent on autophagy and ubiquitin proteasome. Despite not being fully elucidated, the physiological role of prion protein relates to chaperones which rescue cells under stressful conditions.Methamphetamine (METH) is a widely abused drug which produces oxidative stress in various brain areas causing mitochondrial alterations and protein misfolding. These effects produce a compensatory increase of chaperones while clogging cell clearing pathways. In the present study, we explored whether METH administration modifies the amount of PrPc. Since high levels of PrPc when the clearing systems are clogged may lead to its misfolding into PrPsc, we further tested whether METH exposure triggers the appearance of PrPsc. We analysed the effects of METH and dopamine administration in PC12 and striatal cells by using SDS-PAGE Coomassie blue, immune- histochemistry and immune-gold electron microscopy. To analyze whether METH administration produces PrPsc aggregates we used antibodies directed against PrP following exposure to proteinase K or sarkosyl which digest folded PrPc but misfolded PrPsc. We fond that METH triggers PrPsc aggregates in DA-containing cells while METH is not effective in primary striatal neurons which do not produce DA. In the latter cells exogenous DA is needed to trigger PrPsc accumulation similarly to what happens in DA containing cells under the effects of METH. The present findings, while fostering novel molecular mechanisms involving prion proteins, indicate that, cell pathology similar to prion disorders can be mimicked via a DA-dependent mechanism by a drug of abuse.

  9. Insights into the physiological function of cellular prion protein

    Directory of Open Access Journals (Sweden)

    Martins V.R.

    2001-01-01

    Full Text Available Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie, appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction.

  10. Mutation directional selection sheds light on prion pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Liang [Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049 (China); Ji, Hong-Fang, E-mail: jhf@sdut.edu.cn [Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Shandong University of Technology, Zibo 255049 (China)

    2011-07-01

    Highlights: {yields} Most pathogenic mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. {yields} Mutation-induced changes may strengthen the interactions between PrP and facilitating factors. {yields} The findings also have significant implications for exploring potential regions involved in the conformational transition from PrP{sup C} to PrP{sup Sc}. -- Abstract: As mutations in the PRNP gene account for human hereditary prion diseases (PrDs), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (PrP{sup C}) to abnormal scrapie isoform (PrP{sup Sc}). Many studies proposed that these pathogenic mutations may make PrP more susceptible to conformational change through altering its structure stability. By evaluating the most recent observations regarding pathogenic mutations, it was found that the pathogenic mutations do not exert a uniform effect on the thermodynamic stability of the human PrP's structure. Through analyzing the reported PrDs-related mutations, we found that 25 out of 27 mutations possess strong directional selection, i.e., enhancing hydrophobicity or decreasing negative and increasing positive charge. Based on the triggering role reported by previous studies of facilitating factors in PrP{sup C} conversion, e.g., lipid and polyanion, we proposed that the mutation-induced changes may strengthen the interaction between PrP and facilitating factors, which will accelerate PrP conversion and cause PrDs.

  11. Estimating Prion Adsorption Capacity of Soil by BioAssay of Subtracted Infectivity from Complex Solutions (BASICS)

    Science.gov (United States)

    Wyckoff, A. Christy; Lockwood, Krista L.; Meyerett-Reid, Crystal; Michel, Brady A.; Bender, Heather; VerCauteren, Kurt C.; Zabel, Mark D.

    2013-01-01

    Prions, the infectious agent of scrapie, chronic wasting disease and other transmissible spongiform encephalopathies, are misfolded proteins that are highly stable and resistant to degradation. Prions are known to associate with clay and other soil components, enhancing their persistence and surprisingly, transmissibility. Currently, few detection and quantification methods exist for prions in soil, hindering an understanding of prion persistence and infectivity in the environment. Variability in apparent infectious titers of prions when bound to soil has complicated attempts to quantify the binding capacity of soil for prion infectivity. Here, we quantify the prion adsorption capacity of whole, sandy loam soil (SLS) typically found in CWD endemic areas in Colorado; and purified montmorillonite clay (Mte), previously shown to bind prions, by BioAssay of Subtracted Infectivity in Complex Solutions (BASICS). We incubated prion positive 10% brain homogenate from terminally sick mice infected with the Rocky Mountain Lab strain of mouse-adapted prions (RML) with 10% SLS or Mte. After 24 hours samples were centrifuged five minutes at 200×g and soil-free supernatant was intracerebrally inoculated into prion susceptible indicator mice. We used the number of days post inoculation to clinical disease to calculate the infectious titer remaining in the supernatant, which we subtracted from the starting titer to determine the infectious prion binding capacity of SLS and Mte. BASICS indicated SLS bound and removed ≥ 95% of infectivity. Mte bound and removed lethal doses (99.98%) of prions from inocula, effectively preventing disease in the mice. Our data reveal significant prion-binding capacity of soil and the utility of BASICS to estimate prion loads and investigate persistence and decomposition in the environment. Additionally, since Mte successfully rescued the mice from prion disease, Mte might be used for remediation and decontamination protocols. PMID:23484043

  12. Polo-like kinase 3 (PLK3) mediates the clearance of the accumulated PrP mutants transiently expressed in cultured cells and pathogenic PrP(Sc) in prion infected cell line via protein interaction.

    Science.gov (United States)

    Wang, Hui; Tian, Chan; Fan, Xue-Yu; Chen, Li-Na; Lv, Yan; Sun, Jing; Zhao, Yang-Jing; Zhang, Lu-bin; Wang, Jing; Shi, Qi; Gao, Chen; Chen, Cao; Shao, Qi-Xiang; Dong, Xiao-Ping

    2015-05-01

    Polo-like kinases (PLKs) family has long been known to be critical for cell cycle and recent studies have pointed to new dimensions of PLKs function in the nervous system. Our previous study has verified that the levels of PLK3 in the brain are severely downregulated in prion-related diseases. However, the associations of PLKs with prion protein remain unclear. In the present study, we confirmed that PrP protein constitutively interacts with PLK3 as determined by both in vitro and in vivo assays. Both the kinase domain and polo-box domain of PLK3 were proved to bind PrP proteins expressed in mammalian cell lines. Overexpression of PLK3 did not affect the level of wild-type PrP, but significantly decreased the levels of the mutated PrPs in cultured cells. The kinase domain appeared to be responsible for the clearance of abnormally aggregated PrPs, but this function seemed to be independent of its kinase activity. RNA-mediated knockdown of PLK3 obviously aggravated the accumulation of cytosolic PrPs. Moreover, PLK3 overexpression in a scrapie infected cell line caused notable reduce of PrP(Sc) level in a dose-dependent manner, but had minimal effect on the expression of PrP(C) in its normal partner cell line. Our findings here confirmed the molecular interaction between PLK3 and PrP and outlined the regulatory activity of PLK3 on the degradation of abnormal PrPs, even its pathogenic isoform PrP(Sc). We, therefore, assume that the recovery of PLK3 in the early stage of prion infection may be helpful to prevent the toxic accumulation of PrP(Sc) in the brain tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Interaction between 14-3-3β and PrP influences the dimerization of 14-3-3 and fibrillization of PrP106-126.

    Science.gov (United States)

    Han, Jun; Song, Qin-Qin; Sun, Peng; Zhang, Jin; Wang, Xu; Song, Juan; Li, Gong-Qi; Liu, Ying-Hui; Mei, Guo-Yong; Shi, Qi; Tian, Chan; Chen, Cao; Gao, Chen; Zhao, Bo; Dong, Xiao-Ping

    2014-02-01

    Proteins of the 14-3-3 family are universal participate in multiple cellular processes. However, their exact role in the pathogenesis of prion diseases remains unclear. In this study, we proposed that human PrP was able to form molecular complex with 14-3-3β. The domains responsible for the interactions between PrP and 14-3-3β were mapped at the segments of amino acid (aa) residues 106-126 within PrP and aa 1-38 within 14-3-3β. Homology modeling revealed that the key aa residues for molecular interaction were D22 and D23 in 14-3-3β as well as K110 in PrP. Mutations in these aa residues inhibited the interaction between the two proteins in vitro. Our results also showed that recombinant PrP encouraged 14-3-3β dimer formation, whereas PrP106-126 peptide inhibited it. Recombinant 14-3-3β disaggregated the mature PrP106-126 fibrils in vitro. Moreover, the PrP-14-3-3 protein complexes were observed in the brain tissues of normal and scrapie agent 263K infected hamsters. Colocalization of PrP and 14-3-3 was seen in the cytoplasm of human neuroblastoma cell line SH-SY5Y, as well as human cervical cancer cell line HeLa transiently expressing full-length human PrP. Our current data suggest the neuroprotection of PrPC and neuron damage caused by PrPSc may be associated with their functions of 14-3-3 dimerization regulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. A novel Gerstmann-Sträussler-Scheinker disease mutation defines a precursor for amyloidogenic 8 kDa PrP fragments and reveals N-terminal structural changes shared by other GSS alleles

    Science.gov (United States)

    Mercer, Robert C. C.; Fu, Ze-Lin; Mays, Charles E.; Gapeshina, Hristina; Wohlgemuth, Serene L.; Acevedo-Morantes, Claudia Y.; Cashman, Neil R.; Coulthart, Michael B.; Jansen, Gerard H.; Stepanova, Maria

    2018-01-01

    To explore pathogenesis in a young Gerstmann-Sträussler-Scheinker Disease (GSS) patient, the corresponding mutation, an eight-residue duplication in the hydrophobic region (HR), was inserted into the wild type mouse PrP gene. Transgenic (Tg) mouse lines expressing this mutation (Tg.HRdup) developed spontaneous neurologic syndromes and brain extracts hastened disease in low-expressor Tg.HRdup mice, suggesting de novo formation of prions. While Tg.HRdup mice exhibited spongiform change, PrP aggregates and the anticipated GSS hallmark of a proteinase K (PK)-resistant 8 kDa fragment deriving from the center of PrP, the LGGLGGYV insertion also imparted alterations in PrP's unstructured N-terminus, resulting in a 16 kDa species following thermolysin exposure. This species comprises a plausible precursor to the 8 kDa PK-resistant fragment and its detection in adolescent Tg.HRdup mice suggests that an early start to accumulation could account for early disease of the index case. A 16 kDa thermolysin-resistant signature was also found in GSS patients with P102L, A117V, H187R and F198S alleles and has coordinates similar to GSS stop codon mutations. Our data suggest a novel shared pathway of GSS pathogenesis that is fundamentally distinct from that producing structural alterations in the C-terminus of PrP, as observed in other prion diseases such as Creutzfeldt-Jakob Disease and scrapie. PMID:29338055

  15. Sialic Acid on the Glycosylphosphatidylinositol Anchor Regulates PrP-mediated Cell Signaling and Prion Formation.

    Science.gov (United States)

    Bate, Clive; Nolan, William; Williams, Alun

    2016-01-01

    The prion diseases occur following the conversion of the cellular prion protein (PrP(C)) into disease-related isoforms (PrP(Sc)). In this study, the role of the glycosylphosphatidylinositol (GPI) anchor attached to PrP(C) in prion formation was examined using a cell painting technique. PrP(Sc) formation in two prion-infected neuronal cell lines (ScGT1 and ScN2a cells) and in scrapie-infected primary cortical neurons was increased following the introduction of PrP(C). In contrast, PrP(C) containing a GPI anchor from which the sialic acid had been removed (desialylated PrP(C)) was not converted to PrP(Sc). Furthermore, the presence of desialylated PrP(C) inhibited the production of PrP(Sc) within prion-infected cortical neurons and ScGT1 and ScN2a cells. The membrane rafts surrounding desialylated PrP(C) contained greater amounts of sialylated gangliosides and cholesterol than membrane rafts surrounding PrP(C). Desialylated PrP(C) was less sensitive to cholesterol depletion than PrP(C) and was not released from cells by treatment with glimepiride. The presence of desialylated PrP(C) in neurons caused the dissociation of cytoplasmic phospholipase A2 from PrP-containing membrane rafts and reduced the activation of cytoplasmic phospholipase A2. These findings show that the sialic acid moiety of the GPI attached to PrP(C) modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrP(Sc) formation. These results suggest that pharmacological modification of GPI glycosylation might constitute a novel therapeutic approach to prion diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. The mechanisms of humic substances self-assembly with biological molecules: The case study of the prion protein.

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    Gabriele Giachin

    Full Text Available Humic substances (HS are the largest constituent of soil organic matter and are considered as a key component of the terrestrial ecosystem. HS may facilitate the transport of organic and inorganic molecules, as well as the sorption interactions with environmentally relevant proteins such as prions. Prions enter the environment through shedding from live hosts, facilitating a sustained incidence of animal prion diseases such as Chronic Wasting Disease and scrapie in cervid and ovine populations, respectively. Changes in prion structure upon environmental exposure may be significant as they can affect prion infectivity and disease pathology. Despite its relevance, the mechanisms of prion interaction with HS are still not completely understood. The goal of this work is to advance a structural-level picture of the encapsulation of recombinant, non-infectious, prion protein (PrP into different natural HS. We observed that PrP precipitation upon addition of HS is mainly driven by a mechanism of "salting-out" whereby PrP molecules are rapidly removed from the solution and aggregate in insoluble adducts with humic molecules. Importantly, this process does not alter the protein folding since insoluble PrP retains its α-helical content when in complex with HS. The observed ability of HS to promote PrP insolubilization without altering its secondary structure may have potential relevance in the context of "prion ecology". These results suggest that soil organic matter interacts with prions possibly without altering the protein structures. This may facilitate prions preservation from biotic and abiotic degradation leading to their accumulation in the environment.

  17. Prion Replication Elicits Cytopathic Changes in Differentiated Neurosphere Cultures

    Science.gov (United States)

    Iwamaru, Yoshifumi; Takenouchi, Takato; Imamura, Morikazu; Shimizu, Yoshihisa; Miyazawa, Kohtaro; Mohri, Shirou; Yokoyama, Takashi

    2013-01-01

    The molecular mechanisms of prion-induced cytotoxicity remain largely obscure. Currently, only a few cell culture models have exhibited the cytopathic changes associated with prion infection. In this study, we introduced a cell culture model based on differentiated neurosphere cultures isolated from the brains of neonatal prion protein (PrP)-null mice and transgenic mice expressing murine PrP (dNP0 and dNP20 cultures). Upon exposure to mouse Chandler prions, dNP20 cultures supported the de novo formation of abnormal PrP and the resulting infectivity, as assessed by bioassays. Furthermore, this culture was susceptible to various prion strains, including mouse-adapted scrapie, bovine spongiform encephalopathy, and Gerstmann-Sträussler-Scheinker syndrome prions. Importantly, a subset of the cells in the infected culture that was mainly composed of astrocyte lineage cells consistently displayed late-occurring, progressive signs of cytotoxicity as evidenced by morphological alterations, decreased cell viability, and increased lactate dehydrogenase release. These signs of cytotoxicity were not observed in infected dNP0 cultures, suggesting the requirement of endogenous PrP expression for prion-induced cytotoxicity. Degenerated cells positive for glial fibrillary acidic protein accumulated abnormal PrP and exhibited features of apoptotic death as assessed by active caspase-3 and terminal deoxynucleotidyltransferase nick-end staining. Furthermore, caspase inhibition provided partial protection from prion-mediated cell death. These results suggest that differentiated neurosphere cultures can provide an in vitro bioassay for mouse prions and permit the study of the molecular basis for prion-induced cytotoxicity at the cellular level. PMID:23740992

  18. Trends in scientific activity addressing transmissible spongiform encephalopathies: a bibliometric study covering the period 1973–2002

    Directory of Open Access Journals (Sweden)

    Iribarren-Maestro Isabel

    2006-10-01

    Full Text Available Abstract Background The purpose of this study is to analyse the trends in scientific research on transmissible spongiform encephalopathies by applying bibliometric tools to the scientific literature published between 1973 and 2002. Methods The data for the study were obtained from Medline database, in order to determine the volume of scientific output in the above period, the countries involved, the type of document and the trends in the subject matters addressed. The period 1973–2002 was divided in three sub-periods. Results We observed a significant growth in scientific production. The percentage of increase is 871.7 from 1973 to 2002. This is more evident since 1991 and particularly in the 1996–2001 period. The countries found to have the highest output were the United States, the United Kingdom, Japan, France and Germany. The evolution in the subject matters was almost constant in the three sub-periods in which the study was divided. In the first and second sub-periods, the subject matters of greatest interest were more general, i.e Nervous system or Nervous system diseases, Creutzfeldt-Jakob disease, Scrapie, and Chemicals and Drugs, but in the last sub-period, some changes were observed because the Prion-related matters had the greatest presence. Collaboration among authors is small from 1973 to 1992, but increases notably in the third sub-period, and also the number of authors and clusters formed. Some of the authors, like Gajdusek or Prusiner, appear in the whole period. Conclusion The study reveals a very high increase in scientific production. It is related also with the beginnings of research on bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease, with the establishment of progressive collaboration relationships and a reflection of public health concerns about this problem.

  19. Antigenic characterization of an abnormal isoform of prion protein using a new diverse panel of monoclonal antibodies

    International Nuclear Information System (INIS)

    Kim, Chan-Lan; Umetani, Atsushi; Matsui, Toshio; Ishiguro, Naotaka; Shinagawa, Morikazu; Horiuchi, Motohiro

    2004-01-01

    We established a panel of monoclonal antibodies (mAbs) against prion protein (PrP) by immunizing PrP gene-ablated mice with the pathogenic isoform of prion protein (PrP Sc ) or recombinant prion protein (rPrP). The mAbs could be divided into at least 10 groups by fine epitope analyses using mutant rPrPs and pepspot analysis. Seven linear epitopes, lying within residues 56-90, 119-127, 137-143, 143-149, 147-151, 163-169, and 219-229, were defined by seven groups of mAbs, although the remaining three groups of mAbs recognized discontinuous epitopes. We attempted to examine whether any of these epitopes are located on the accessible surface of PrP Sc . However, no mAbs reacted with protease-treated PrP Sc purified from scrapie-affected mice, even when PrP Sc was dispersed into a detergent-lipid protein complex, to reduce the size of PrP Sc aggregates. In contrast, denaturation of PrP Sc by guanidine hydrochloride efficiently exposed all of the epitopes. This suggests that any epitope recognized by this panel of mAbs is buried within the PrP Sc aggregates. Alternatively, if the corresponding region(s) are on the surface of PrP Sc , the region(s) may be folded into conformations to which the mAbs cannot bind. The reactivity of a panel of mAb also showed that the state of PrP Sc aggregation influenced the denaturation process, and the sensitivity to denaturation appeared to vary between epitopes. Our results demonstrate that this new panel of well-characterized mAbs will be valuable for studying the biochemistry and biophysics of PrP molecules as well as for the immuno-diagnosis of prion diseases

  20. Removal process of prion and parvovirus from human platelet lysates used as clinical-grade supplement for ex vivo cell expansion.

    Science.gov (United States)

    Kao, Yu-Chun; Bailey, Andy; Samminger, Bernhard; Tanimoto, Junji; Burnouf, Thierry

    2016-07-01

    Pooled human platelet lysate (HPL) is becoming the new gold standard as supplement for ex vivo cell culture for clinical protocols. However, the risk of pathogen contamination of HPL increases with the platelet pool size. We hypothesized that hollow fiber anion exchange membrane chromatography using QyuSpeed D (QSD) could remove resistant and untested bloodborne pathogens, such as parvoviruses and prions, from HPL-supplemented growth media without substantially affecting their capacity to support ex vivo cell expansion. Frozen or thawed platelet concentrates were serum-converted and centrifuged for obtaining HPL that was added to various growth media (ca. 100 mL), filtered through a 0.6-mL QSD membrane and characterized for proteins, growth factors and chemical composition. Capacity to expand Chinese hamster ovary, periodontal ligament, gingival fibroblast cells and Wharton's jelly mesenchymal stromal cells was studied. Removal of porcine parvovirus (PPV) and of the 263K prion strain of hamster-adapted scrapie was studied by spiking experiments following international guidelines. QSD had minimal impact on HPL-supplemented medium composition in proteins, growth factors and chemical content, nor capacity to expand and differentiate cells. In addition, QSD could remove ≥5.58 log10 [TCID50/mL] and ≥3.72 log10 of PPV and the 263K prion, respectively. QSD hollow fiber chromatography can be used to improve the virus and prion safety of HPL-supplemented media to safely expand cells for clinical protocols. These data bring new perspectives for increasingly safer use of pooled HPL in cell therapy and regenerative medicine applications. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  1. Plasminogen stimulates propagation of protease-resistant prion protein in vitro.

    Science.gov (United States)

    Mays, Charles E; Ryou, Chongsuk

    2010-12-01

    To clarify the role of plasminogen as a cofactor for prion propagation, we conducted functional assays using a cell-free prion protein (PrP) conversion assay termed protein misfolding cyclic amplification (PMCA) and prion-infected cell lines. Here, we report that plasminogen stimulates propagation of the protease-resistant scrapie PrP (PrP(Sc)). Compared to control PMCA conducted without plasminogen, addition of plasminogen in PMCA using wild-type brain material significantly increased PrP conversion, with an EC(50) = ∼56 nM. PrP conversion in PMCA was substantially less efficient with plasminogen-deficient brain material than with wild-type material. The activity stimulating PrP conversion was specific for plasminogen and conserved in its kringle domains. Such activity was abrogated by modification of plasminogen structure and interference of PrP-plasminogen interaction. Kinetic analysis of PrP(Sc) generation demonstrated that the presence of plasminogen in PMCA enhanced the PrP(Sc) production rate to ∼0.97 U/μl/h and reduced turnover time to ∼1 h compared to those (∼0.4 U/μl/h and ∼2.5 h) obtained without supplementation. Furthermore, as observed in PMCA, plasminogen and kringles promoted PrP(Sc) propagation in ScN2a and Elk 21(+) cells. Our results demonstrate that plasminogen functions in stimulating conversion processes and represents the first cellular protein cofactor that enhances the hypothetical mechanism of prion propagation.

  2. Prion protein accumulation in lipid rafts of mouse aging brain.

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    Federica Agostini

    Full Text Available The cellular form of the prion protein (PrP(C is a normal constituent of neuronal cell membranes. The protein misfolding causes rare neurodegenerative disorders known as transmissible spongiform encephalopathies or prion diseases. These maladies can be sporadic, genetic or infectious. Sporadic prion diseases are the most common form mainly affecting aging people. In this work, we investigate the biochemical environment in which sporadic prion diseases may develop, focusing our attention on the cell membrane of neurons in the aging brain. It is well established that with aging the ratio between the most abundant lipid components of rafts undergoes a major change: while cholesterol decreases, sphingomyelin content rises. Our results indicate that the aging process modifies the compartmentalization of PrP(C. In old mice, this change favors PrP(C accumulation in detergent-resistant membranes, particularly in hippocampi. To confirm the relationship between lipid content changes and PrP(C translocation into detergent-resistant membranes (DRMs, we looked at PrP(C compartmentalization in hippocampi from acid sphingomyelinase (ASM knockout (KO mice and synaptosomes enriched in sphingomyelin. In the presence of high sphingomyelin content, we observed a significant increase of PrP(C in DRMS. This process is not due to higher levels of total protein and it could, in turn, favor the onset of sporadic prion diseases during aging as it increases the PrP intermolecular contacts into lipid rafts. We observed that lowering sphingomyelin in scrapie-infected cells by using fumonisin B1 led to a 50% decrease in protease-resistant PrP formation. This may suggest an involvement of PrP lipid environment in prion formation and consequently it may play a role in the onset or development of sporadic forms of prion diseases.

  3. Prion Protein Promotes Kidney Iron Uptake via Its Ferrireductase Activity*

    Science.gov (United States)

    Haldar, Swati; Tripathi, Ajai; Qian, Juan; Beserra, Amber; Suda, Srinivas; McElwee, Matthew; Turner, Jerrold; Hopfer, Ulrich; Singh, Neena

    2015-01-01

    Brain iron-dyshomeostasis is an important cause of neurotoxicity in prion disorders, a group of neurodegenerative conditions associated with the conversion of prion protein (PrPC) from its normal conformation to an aggregated, PrP-scrapie (PrPSc) isoform. Alteration of iron homeostasis is believed to result from impaired function of PrPC in neuronal iron uptake via its ferrireductase activity. However, unequivocal evidence supporting the ferrireductase activity of PrPC is lacking. Kidney provides a relevant model for this evaluation because PrPC is expressed in the kidney, and ∼370 μg of iron are reabsorbed daily from the glomerular filtrate by kidney proximal tubule cells (PT), requiring ferrireductase activity. Here, we report that PrPC promotes the uptake of transferrin (Tf) and non-Tf-bound iron (NTBI) by the kidney in vivo and mainly NTBI by PT cells in vitro. Thus, uptake of 59Fe administered by gastric gavage, intravenously, or intraperitoneally was significantly lower in PrP-knock-out (PrP−/−) mouse kidney relative to PrP+/+ controls. Selective in vivo radiolabeling of plasma NTBI with 59Fe revealed similar results. Expression of exogenous PrPC in immortalized PT cells showed localization on the plasma membrane and intracellular vesicles and increased transepithelial transport of 59Fe-NTBI and to a smaller extent 59Fe-Tf from the apical to the basolateral domain. Notably, the ferrireductase-deficient mutant of PrP (PrPΔ51–89) lacked this activity. Furthermore, excess NTBI and hemin caused aggregation of PrPC to a detergent-insoluble form, limiting iron uptake. Together, these observations suggest that PrPC promotes retrieval of iron from the glomerular filtrate via its ferrireductase activity and modulates kidney iron metabolism. PMID:25572394

  4. Region-specific protein misfolding cyclic amplification reproduces brain tropism of prion strains.

    Science.gov (United States)

    Privat, Nicolas; Levavasseur, Etienne; Yildirim, Serfildan; Hannaoui, Samia; Brandel, Jean-Philippe; Laplanche, Jean-Louis; Béringue, Vincent; Seilhean, Danielle; Haïk, Stéphane

    2017-10-06

    Human prion diseases such as Creutzfeldt-Jakob disease are transmissible brain proteinopathies, characterized by the accumulation of a misfolded isoform of the host cellular prion protein (PrP) in the brain. According to the prion model, prions are defined as proteinaceous infectious particles composed solely of this abnormal isoform of PrP (PrP Sc ). Even in the absence of genetic material, various prion strains can be propagated in experimental models. They can be distinguished by the pattern of disease they produce and especially by the localization of PrP Sc deposits within the brain and the spongiform lesions they induce. The mechanisms involved in this strain-specific targeting of distinct brain regions still are a fundamental, unresolved question in prion research. To address this question, we exploited a prion conversion in vitro assay, protein misfolding cyclic amplification (PMCA), by using experimental scrapie and human prion strains as seeds and specific brain regions from mice and humans as substrates. We show here that region-specific PMCA in part reproduces the specific brain targeting observed in experimental, acquired, and sporadic Creutzfeldt-Jakob diseases. Furthermore, we provide evidence that, in addition to cellular prion protein, other region- and species-specific molecular factors influence the strain-dependent prion conversion process. This important step toward understanding prion strain propagation in the human brain may impact research on the molecular factors involved in protein misfolding and the development of ultrasensitive methods for diagnosing prion disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Shaking alone induces de novo conversion of recombinant prion proteins to β-sheet rich oligomers and fibrils.

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    Carol L Ladner-Keay

    Full Text Available The formation of β-sheet rich prion oligomers and fibrils from native prion protein (PrP is thought to be a key step in the development of prion diseases. Many methods are available to convert recombinant prion protein into β-sheet rich fibrils using various chemical denaturants (urea, SDS, GdnHCl, high temperature, phospholipids, or mildly acidic conditions (pH 4. Many of these methods also require shaking or another form of agitation to complete the conversion process. We have identified that shaking alone causes the conversion of recombinant PrP to β-sheet rich oligomers and fibrils at near physiological pH (pH 5.5 to pH 6.2 and temperature. This conversion does not require any denaturant, detergent, or any other chemical cofactor. Interestingly, this conversion does not occur when the water-air interface is eliminated in the shaken sample. We have analyzed shaking-induced conversion using circular dichroism, resolution enhanced native acidic gel electrophoresis (RENAGE, electron microscopy, Fourier transform infrared spectroscopy, thioflavin T fluorescence and proteinase K resistance. Our results show that shaking causes the formation of β-sheet rich oligomers with a population distribution ranging from octamers to dodecamers and that further shaking causes a transition to β-sheet fibrils. In addition, we show that shaking-induced conversion occurs for a wide range of full-length and truncated constructs of mouse, hamster and cervid prion proteins. We propose that this method of conversion provides a robust, reproducible and easily accessible model for scrapie-like amyloid formation, allowing the generation of milligram quantities of physiologically stable β-sheet rich oligomers and fibrils. These results may also have interesting implications regarding our understanding of prion conversion and propagation both within the brain and via techniques such as protein misfolding cyclic amplification (PMCA and quaking induced conversion (QuIC.

  6. Inactivation of Template-Directed Misfolding of Infectious Prion Protein by Ozone

    Science.gov (United States)

    Ding, Ning; Price, Luke M.; Braithwaite, Shannon L.; Balachandran, Aru; Belosevic, Miodrag

    2012-01-01

    Misfolded prions (PrPSc) are well known for their resistance to conventional decontamination processes. The potential risk of contamination of the water environment, as a result of disposal of specified risk materials (SRM), has raised public concerns. Ozone is commonly utilized in the water industry for inactivation of microbial contaminants and was tested in this study for its ability to inactivate prions (263K hamster scrapie = PrPSc). Treatment variables included initial ozone dose (7.6 to 25.7 mg/liter), contact time (5 s and 5 min), temperature (4°C and 20°C), and pH (pH 4.4, 6.0, and 8.0). Exposure of dilute suspensions of the infected 263K hamster brain homogenates (IBH) (0.01%) to ozone resulted in the in vitro destruction of the templating properties of PrPSc, as measured by the protein misfolding cyclic amplification (PMCA) assay. The highest levels of prion inactivation (≥4 log10) were observed with ozone doses of 13.0 mg/liter, at pH 4.4 and 20°C, resulting in a CT (the product of residual ozone concentration and contact time) value as low as 0.59 mg · liter−1 min. A comparison of ozone CT requirements among various pathogens suggests that prions are more susceptible to ozone degradation than some model bacteria and protozoa and that ozone treatment may be an effective solution for inactivating prions in water and wastewater. PMID:22138993

  7. Snord 3A: A Molecular Marker and Modulator of Prion Disease Progression

    Science.gov (United States)

    Cohen, Eran; Avrahami, Dana; Frid, Kati; Canello, Tamar; Levy Lahad, Ephrat; Zeligson, Sharon; Perlberg, Shira; Chapman, Joab; Cohen, Oren S.; Kahana, Esther; Lavon, Iris; Gabizon, Ruth

    2013-01-01

    Since preventive treatments for prion disease require early identification of subjects at risk, we searched for surrogate peripheral markers characterizing the asymptomatic phases of such conditions. To this effect, we subjected blood mRNA from E200K PrP CJD patients and corresponding family members to global arrays and found that the expression of Snord3A, a non-coding RNA transcript, was elevated several times in CJD patients as compared to controls, while asymptomatic carriers presented intermediate Snord3A levels. In the brains of TgMHu2ME199K mice, a mouse model mimicking for E200K CJD, Snord 3A levels were elevated in an age and disease severity dependent manner, as was the case for brains of these mice in which disease was exacerbated by copper administration. Snord3A expression was also elevated in scrapie infected mice, but not in PrP0/0 mice, indicating that while the expression levels of this transcript may reflect diverse prion etiologies, they are not related to the loss of PrPC’s function. Elevation of Snord3A was consistent with the activation of ATF6, representing one of the arms of the unfolded protein response system. Indeed, SnoRNAs were associated with reduced resistance to oxidative stress, and with ER stress in general, factors playing a significant role in this and other neurodegenerative conditions. We hypothesize that in addition to its function as a disease marker, Snord3A may play an important role in the mechanism of prion disease manifestation and progression. PMID:23349890

  8. Snord 3A: a molecular marker and modulator of prion disease progression.

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    Eran Cohen

    Full Text Available Since preventive treatments for prion disease require early identification of subjects at risk, we searched for surrogate peripheral markers characterizing the asymptomatic phases of such conditions. To this effect, we subjected blood mRNA from E200K PrP CJD patients and corresponding family members to global arrays and found that the expression of Snord3A, a non-coding RNA transcript, was elevated several times in CJD patients as compared to controls, while asymptomatic carriers presented intermediate Snord3A levels. In the brains of TgMHu2ME199K mice, a mouse model mimicking for E200K CJD, Snord 3A levels were elevated in an age and disease severity dependent manner, as was the case for brains of these mice in which disease was exacerbated by copper administration. Snord3A expression was also elevated in scrapie infected mice, but not in PrP(0/0 mice, indicating that while the expression levels of this transcript may reflect diverse prion etiologies, they are not related to the loss of PrP(C's function. Elevation of Snord3A was consistent with the activation of ATF6, representing one of the arms of the unfolded protein response system. Indeed, SnoRNAs were associated with reduced resistance to oxidative stress, and with ER stress in general, factors playing a significant role in this and other neurodegenerative conditions. We hypothesize that in addition to its function as a disease marker, Snord3A may play an important role in the mechanism of prion disease manifestation and progression.

  9. Population-level retrospective study of neurologically expressed disorders in ruminants before the onset of bovine spongiform encephalopathy (BSE) in Belgium, a BSE risk III country.

    Science.gov (United States)

    Saegerman, C; Berkvens, D; Claes, L; Dewaele, A; Coignoul, F; Ducatelle, R; Cassart, D; Brochier, B; Costy, F; Roels, S; Deluyker, H; Vanopdenbosch, E; Thiry, E

    2005-02-01

    A retrospective epidemiological study (n = 7,875) of neurologically expressed disorders (NED) in ruminants before the onset of the bovine spongiform encephalopathy epidemic (years studied, 1980 to 1997) was carried out in Belgium. The archives of all veterinary laboratories and rabies and transmissible spongiform encephalopathy (TSE) epidemiosurveillance networks were consulted. For all species, a significantly higher number of NED with virological causes (rabies) was reported south of the Sambre-Meuse Valley. During the period 1992 to 1997, for which the data were complete, (i) the predicted annual incidence of NED varied significantly as a function of species and area (higher numbers in areas where rabies was present) but was always above 100 cases per million, and (ii) the mean incidence of suspected TSE cases and, among them, those investigated by histopathological examination varied significantly as a function of species and area. The positive predictive value of a presumptive clinical diagnosis of NED ranged from 0.13 (game) to 0.63 (sheep). Knowledge of the positive predictive value permits the definition of a reference point before certain actions (e.g., awareness and training campaigns) are undertaken. It also shows the usefulness of a systematic necropsy or complementary laboratory tests to establish an etiological diagnosis. TSE analysis of a small, targeted historical sampling (n = 48) permitted the confirmation of one case and uncovered another case of scrapie. The results of the present study help to develop and maintain the quality of the worldwide clinical epidemiological networks for TSE, especially in countries that in the past imported live animals, animal products, and feedstuffs from countries with TSE cases.

  10. Choroba Creutzfeldta-Jakoba − współczesne metody diagnostyki

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    Marianna Makowska

    2013-11-01

    Full Text Available Choroba Creutzfeldta-Jakoba (Creutzfeldt-Jakob disease, CJD należy do chorób wywoływanych przez priony (encefalopatii gąbczastych. Jest to postępująca, śmiertelna i nieuleczalna choroba o charakterze neurozwyrodnieniowym. Jej przyczyną jest akumulacja patologicznego białka prionu (scrapie, PrPSc w ośrodkowym układzie nerwowym. Choroba objawia się postępującym otępieniem, zaburzeniami mowy i wzroku oraz motoryki pod postacią mioklonii, ataksji oraz niedowładu kończyn i zaburzeń równowagi. Bezpośrednią przyczyną zgonu jest najczęściej odoskrzelowe zapalenie płuc. Okres inkubacji choroby wynosi zazwyczaj od kilku do kilkunastu lat, a zgon następuje najczęściej od kilku do kilkunastu miesięcy od wystąpienia pierwszych objawów klinicznych. Trudności w przyżyciowym rozpoznawaniu choroby Creutzfeldta-Jakoba wynikają z braku swoistego markera umożliwiającego pewną identyfikację czynnika infekcyjnego oraz nie zawsze charakterystycznego obrazu klinicznego wymagającego różnicowania z innymi chorobami o charakterze otępiennym. Aktualnie jedyną pewną metodą rozpoznania jest przeprowadzenie badania neuropatologicznego. Klasyczna triada objawów neuropatologicznych występujących w przebiegu chorób wywoływanych przez priony obejmuje zmiany gąbczaste, rozplem astrogleju oraz utratę neuronów. Publikacja jest przeglądem aktualnych informacji na temat najnowszych metod diagnostycznych, w tym EEG, badań neuroobrazowych oraz laboratoryjnych, które znacznie poprawiły możliwość rozpoznania.

  11. Efficient prion disease transmission through common environmental materials.

    Science.gov (United States)

    Pritzkow, Sandra; Morales, Rodrigo; Lyon, Adam; Concha-Marambio, Luis; Urayama, Akihiko; Soto, Claudio

    2018-03-02

    Prion diseases are a group of fatal neurodegenerative diseases associated with a protein-based infectious agent, termed prion. Compelling evidence suggests that natural transmission of prion diseases is mediated by environmental contamination with infectious prions. We hypothesized that several natural and man-made materials, commonly found in the environments of wild and captive animals, can bind prions and may act as vectors for disease transmission. To test our hypothesis, we exposed surfaces composed of various common environmental materials ( i.e. wood, rocks, plastic, glass, cement, stainless steel, aluminum, and brass) to hamster-adapted 263K scrapie prions and studied their attachment and retention of infectivity in vitro and in vivo Our results indicated that these surfaces, with the sole exception of brass, efficiently bind, retain, and release prions. Prion replication was studied in vitro using the protein misfolding cyclic amplification technology, and infectivity of surface-bound prions was analyzed by intracerebrally challenging hamsters with contaminated implants. Our results revealed that virtually all prion-contaminated materials transmitted the disease at high rates. To investigate a more natural form of exposure to environmental contamination, we simply housed animals with large contaminated spheres made of the different materials under study. Strikingly, most of the hamsters developed classical clinical signs of prion disease and typical disease-associated brain changes. Our findings suggest that prion contamination of surfaces commonly present in the environment can be a source of disease transmission, thus expanding our understanding of the mechanisms for prion spreading in nature. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Rapid and Highly Sensitive Detection of Variant Creutzfeldt-Jakob Disease Abnormal Prion Protein on Steel Surfaces by Protein Misfolding Cyclic Amplification: Application to Prion Decontamination Studies.

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    Maxime Belondrade

    Full Text Available The prevalence of variant Creutzfeldt-Jakob disease (vCJD in the population remains uncertain, although it has been estimated that 1 in 2000 people in the United Kingdom are positive for abnormal prion protein (PrPTSE by a recent survey of archived appendix tissues. The prominent lymphotropism of vCJD prions raises the possibility that some surgical procedures may be at risk of iatrogenic vCJD transmission in healthcare facilities. It is therefore vital that decontamination procedures applied to medical devices before their reprocessing are thoroughly validated. A current limitation is the lack of a rapid model permissive to human prions. Here, we developed a prion detection assay based on protein misfolding cyclic amplification (PMCA technology combined with stainless-steel wire surfaces as carriers of prions (Surf-PMCA. This assay allowed the specific detection of minute quantities (10-8 brain dilution of either human vCJD or ovine scrapie PrPTSE adsorbed onto a single steel wire, within a two week timeframe. Using Surf-PMCA we evaluated the performance of several reference and commercially available prion-specific decontamination procedures. Surprisingly, we found the efficiency of several marketed reagents to remove human vCJD PrPTSE was lower than expected. Overall, our results demonstrate that Surf-PMCA can be used as a rapid and ultrasensitive assay for the detection of human vCJD PrPTSE adsorbed onto a metallic surface, therefore facilitating the development and validation of decontamination procedures against human prions.

  13. The prion protein has DNA strand transfer properties similar to retroviral nucleocapsid protein.

    Science.gov (United States)

    Gabus, C; Auxilien, S; Péchoux, C; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W; Nandi, P; Darlix, J L

    2001-04-06

    The transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are associated with the accumulation of a protease-resistant form of the cellular prion protein (PrP). Although PrP is highly conserved and widely expressed in vertebrates, its function remains a matter of speculation. Indeed PrP null mice develop normally and are healthy. Recent results show that PrP binds to nucleic acids in vitro and is found associated with retroviral particles. Furthermore, in mice the scrapie infectious process appears to be accelerated by MuLV replication. These observations prompted us to further investigate the interaction between PrP and nucleic acids, and compare it with that of the retroviral nucleocapsid protein (NC). As the major nucleic acid-binding protein of the retroviral particle, NC protein is tightly associated with the genomic RNA in the virion nucleocapsid, where it chaperones proviral DNA synthesis by reverse transcriptase. Our results show that the human prion protein (huPrP) functionally resembles NCp7 of HIV-1. Both proteins form large nucleoprotein complexes upon binding to DNA. They accelerate the hybridization of complementary DNA strands and chaperone viral DNA synthesis during the minus and plus DNA strand transfers necessary to generate the long terminal repeats. The DNA-binding and strand transfer properties of huPrP appear to map to the N-terminal fragment comprising residues 23 to 144, whereas the C-terminal domain is inactive. These findings suggest that PrP could be involved in nucleic acid metabolism in vivo. Copyright 2001 Academic Press.

  14. Prion pathogenesis is unaltered in the absence of SIRPα-mediated "don't-eat-me" signaling.

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    Mario Nuvolone

    Full Text Available Prion diseases are neurodegenerative conditions caused by misfolding of the prion protein, leading to conspicuous neuronal loss and intense microgliosis. Recent experimental evidence point towards a protective role of microglia against prion-induced neurodegeneration, possibly through elimination of prion-containing apoptotic bodies. The molecular mechanisms by which microglia recognize and eliminate apoptotic cells in the context of prion diseases are poorly defined. Here we investigated the possible involvement of signal regulatory protein α (SIRPα, a key modulator of host cell phagocytosis; SIRPα is encoded by the Sirpa gene that is genetically linked to the prion gene Prnp. We found that Sirpa transcripts are highly enriched in microglia cells within the brain. However, Sirpa mRNA levels were essentially unaltered during the course of experimental prion disease despite upregulation of other microglia-enriched transcripts. To study the involvement of SIRPα in prion pathogenesis in vivo, mice expressing a truncated SIRPα protein unable to inhibit phagocytosis were inoculated with rodent-adapted scrapie prions of the 22L strain. Homozygous and heterozygous Sirpa mutants and wild-type mice experienced similar incubation times after inoculation with either of two doses of 22L prions. Moreover, the extent of neuronal loss, microgliosis and abnormal prion protein accumulation was not significantly affected by Sirpa genotypes. Collectively, these data indicate that SIRPα-mediated phagocytosis is not a major determinant in prion disease pathogenesis. It will be important to search for additional candidates mediating prion phagocytosis, as this mechanism may represent an important target of antiprion therapies.

  15. Prion protein misfolding affects calcium homeostasis and sensitizes cells to endoplasmic reticulum stress.

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    Mauricio Torres

    2010-12-01

    Full Text Available Prion-related disorders (PrDs are fatal neurodegenerative disorders characterized by progressive neuronal impairment as well as the accumulation of an abnormally folded and protease resistant form of the cellular prion protein, termed PrP(RES. Altered endoplasmic reticulum (ER homeostasis is associated with the occurrence of neurodegeneration in sporadic, infectious and familial forms of PrDs. The ER operates as a major intracellular calcium store, playing a crucial role in pathological events related to neuronal dysfunction and death. Here we investigated the possible impact of PrP misfolding on ER calcium homeostasis in infectious and familial models of PrDs. Neuro2A cells chronically infected with scrapie prions showed decreased ER-calcium content that correlated with a stronger upregulation of UPR-inducible chaperones, and a higher sensitivity to ER stress-induced cell death. Overexpression of the calcium pump SERCA stimulated calcium release and increased the neurotoxicity observed after exposure of cells to brain-derived infectious PrP(RES. Furthermore, expression of PrP mutants that cause hereditary Creutzfeldt-Jakob disease or fatal familial insomnia led to accumulation of PrP(RES and their partial retention at the ER, associated with a drastic decrease of ER calcium content and higher susceptibility to ER stress. Finally, similar results were observed when a transmembrane form of PrP was expressed, which is proposed as a neurotoxic intermediate. Our results suggest that alterations in calcium homeostasis and increased susceptibility to ER stress are common pathological features of both infectious and familial PrD models.

  16. Sex and PRNP genotype determination in preimplantation caprine embryos.

    Science.gov (United States)

    Guignot, F; Perreau, C; Cavarroc, C; Touzé, J-L; Pougnard, J-L; Dupont, F; Beckers, J-F; Rémy, B; Babilliot, J-M; Bed'Hom, B; Lamorinière, J M; Mermillod, P; Baril, G

    2011-08-01

    The objective of this study was to test the accuracy of genotype diagnosis after whole amplification of DNA extracted from biopsies obtained by trimming goat embryos and to evaluate the viability of biopsied embryos after vitrification/warming and transfer. Whole genome amplification (WGA) was performed using Multiple Displacement Amplification (MDA). Sex and prion protein (PRNP) genotypes were determined. Sex diagnosis was carried out by PCR amplification of ZFX/ZFY and Y chromosome-specific sequences. Prion protein genotype determination was performed on codons 142, 154, 211, 222 and 240. Embryos were collected at day 7 after oestrus and biopsied either immediately after collection (blastocysts and expanded blastocysts) or after 24 h of in vitro culture (compacted morulae). Biopsied embryos were frozen by vitrification. Vitrified whole embryos were kept as control. DNA of biopsies was extracted and amplified using MDA. Sex diagnosis was efficient for 97.4% of biopsies and PRNP genotyping was determined in 78.7% of biopsies. After embryo transfer, no significant difference was observed in kidding rate between biopsied and vitrified control embryos, whereas embryo survival rate was different between biopsied and whole vitrified embryos (p = 0.032). At birth, 100% of diagnosed sex and 98.2% of predetermined codons were correct. Offspring PRNP profiles were in agreement with parental genotype. Whole genome amplification with MDA kit coupled with sex diagnosis and PRNP genotype predetermination are very accurate techniques to genotype goat embryos before transfer. These novel results allow us to plan selection of scrapie-resistant genotypes and kid sex before transfer of cryopreserved embryo. © 2010 Blackwell Verlag GmbH.

  17. Comparative evidence for a link between Peyer's patch development and susceptibility to transmissible spongiform encephalopathies

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    Rhind Susan M

    2006-01-01

    Full Text Available Abstract Background Epidemiological analyses indicate that the age distribution of natural cases of transmissible spongiform encephalopathies (TSEs reflect age-related risk of infection, however, the underlying mechanisms remain poorly understood. Using a comparative approach, we tested the hypothesis that, there is a significant correlation between risk of infection for scrapie, bovine spongiform encephalopathy (BSE and variant CJD (vCJD, and the development of lymphoid tissue in the gut. Methods Using anatomical data and estimates of risk of infection in mathematical models (which included results from previously published studies for sheep, cattle and humans, we calculated the Spearman's rank correlation coefficient, rs, between available measures of Peyer's patch (PP development and the estimated risk of infection for an individual of the corresponding age. Results There was a significant correlation between the measures of PP development and the estimated risk of TSE infection; the two age-related distributions peaked in the same age groups. This result was obtained for each of the three host species: for sheep, surface area of ileal PP tissue vs risk of infection, rs = 0.913 (n = 19, P s = 0.933 (n = 19, P s = 0.693 (n = 94, P s = 0.384 (n = 46, P = 0.008. In addition, when changes in exposure associated with BSE-contaminated meat were accounted for, the two age-related patterns for humans remained concordant: rs = 0.360 (n = 46, P = 0.014. Conclusion Our findings suggest that, for sheep, cattle and humans alike there is an association between PP development (or a correlate of PP development and susceptibility to natural TSE infection. This association may explain changes in susceptibility with host age, and differences in the age-susceptibility relationship between host species.

  18. Is prnt a pseudogene? Identification of ram Prt in testis and ejaculated spermatozoa.

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    Jorge Pimenta

    Full Text Available A hallmark of prion diseases or transmissible spongiform encephalopaties is the conversion of the cellular prion protein (PrP(C, expressed by the prion gene (prnp, into an abnormally folded isoform (PrP(Sc with amyloid-like features that causes scrapie in sheep among other diseases. prnp together with prnd (which encodes a prion-like protein designated as Doppel, and prnt (that encodes the prion protein testis specific--Prt with sprn (shadow of prion protein gene, that encodes Shadoo or Sho genes, constitute the "prion gene complex". Whereas a role for prnd in the proper functioning of male reproductive system has been confirmed, the function of prnt, a recently discovered prion family gene, comprises a conundrum leading to the assumption that ruminant prnt is a pseudogene with no protein expression. The main objective of the present study was to identify Prt localization in the ram reproductive system and simultaneously to elucidate if ovine prnt gene is transcribed into protein-coding RNA. Moreover, as Prt is a prnp-related protein, the amyloid propensity was also tested for ovine and caprine Prt. Recombinant Prt was used to immunize BALB/c mice, and the anti-Prt polyclonal antibody (APPA immune response was evaluated by ELISA and Western Blot. When tested by indirect immunofluorescence, APPA showed high avidity to the ram sperm head apical ridge subdomain, before and after induced capacitation, but did not show the same behavior against goat spermatozoa, suggesting high antibody specificity against ovine-Prt. Prt was also found in the testis when assayed by immunohistochemistry during ram spermatogenesis, where spermatogonia, spermatocytes, spermatids and spermatozoa, stained positive. These observations strongly suggest ovine prnt to be a translated protein-coding gene, pointing to a role for Prt protein in the ram reproductive physiology. Besides, caprine Prt appears to exhibit a higher amyloid propensity than ovine Prt, mostly associated

  19. El silenciamiento de la proteína priónica celular (PrPC mediante RNA de interferencia (siRNA reduce la infección por HSV-1 y HSV-2 en células SK-SY5Y

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    Elizabeth Ortega-Soto

    2012-01-01

    Full Text Available Las encefalopatías espongiformes transmisibles (EETs son enfermedades neurodegenerativas fatales que afectan a humanos y ciertas especies animales. La hipótesis más aceptada indica que el agente infeccioso, denotado como prion y compuesto principalmente por la Proteína Priónica Scrapie (PrPSc, corresponde a una conformación anormal de una proteína codificada por el huésped denominada Proteína Priónica Celular (PrPC, cuya función es aún desconocida; sin embargo, la expresión ubicua de PrPC así como su elevado grado de conservación entre especies, sugieren un papel importante para esta proteína. En este trabajo se detectó a la PrPC en diferentes tipos celulares incluyendo un cultivo primario de células de peces (Tilapia, Oreochromis spp.. Además, basándonos en la secuencia de la PrPC humana, se diseñó un RNA de interferencia (siRNA con el fin de silenciar el gen PRNP en células neuronales SK-SY5Y. El siRNA diseñado inhibió la expresión de PrPC a lo largo de las 96 h post-transfección y las células silenciadas fueron menos susceptibles a la infección por HSV-1 y HSV-2, en comparación con células no transfectadas con el siRNA.

  20. Glypican-1 mediates both prion protein lipid raft association and disease isoform formation.

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    David R Taylor

    2009-11-01

    Full Text Available In prion diseases, the cellular form of the prion protein, PrP(C, undergoes a conformational conversion to the infectious isoform, PrP(Sc. PrP(C associates with lipid rafts through its glycosyl-phosphatidylinositol (GPI anchor and a region in its N-terminal domain which also binds to heparan sulfate proteoglycans (HSPGs. We show that heparin displaces PrP(C from rafts and promotes its endocytosis, suggesting that heparin competes with an endogenous raft-resident HSPG for binding to PrP(C. We then utilised a transmembrane-anchored form of PrP (PrP-TM, which is targeted to rafts solely by its N-terminal domain, to show that both heparin and phosphatidylinositol-specific phospholipase C can inhibit its association with detergent-resistant rafts, implying that a GPI-anchored HSPG targets PrP(C to rafts. Depletion of the major neuronal GPI-anchored HSPG, glypican-1, significantly reduced the raft association of PrP-TM and displaced PrP(C from rafts, promoting its endocytosis. Glypican-1 and PrP(C colocalised on the cell surface and both PrP(C and PrP(Sc co-immunoprecipitated with glypican-1. Critically, treatment of scrapie-infected N2a cells with glypican-1 siRNA significantly reduced PrP(Sc formation. In contrast, depletion of glypican-1 did not alter the inhibitory effect of PrP(C on the beta-secretase cleavage of the Alzheimer's amyloid precursor protein. These data indicate that glypican-1 is a novel cellular cofactor for prion conversion and we propose that it acts as a scaffold facilitating the interaction of PrP(C and PrP(Sc in lipid rafts.

  1. Effect of Q211 and K222 PRNP Polymorphic Variants in the Susceptibility of Goats to Oral Infection With Goat Bovine Spongiform Encephalopathy.

    Science.gov (United States)

    Aguilar-Calvo, Patricia; Fast, Christine; Tauscher, Kerstin; Espinosa, Juan-Carlos; Groschup, Martin H; Nadeem, Muhammad; Goldmann, Wilfred; Langeveld, Jan; Bossers, Alex; Andreoletti, Olivier; Torres, Juan-María

    2015-08-15

    The prion protein-encoding gene (PRNP) is one of the major determinants for scrapie occurrence in sheep and goats. However, its effect on bovine spongiform encephalopathy (BSE) transmission to goats is not clear. Goats harboring wild-type, R/Q211 or Q/K222 PRNP genotypes were orally inoculated with a goat-BSE isolate to assess their relative susceptibility to BSE infection. Goats were killed at different time points during the incubation period and after the onset of clinical signs, and their brains as well as several peripheral tissues were analyzed for the accumulation of pathological prion protein (PrP(Sc)) and prion infectivity by mouse bioassay. R/Q211 goats displayed delayed clinical signs compared with wild-type goats. Deposits of PrP(Sc) were detected only in brain, whereas infectivity was present in peripheral tissues too. In contrast, none of the Q/K222 goats showed any evidence of clinical prion disease. No PrP(Sc) accumulation was observed in their brains or peripheral tissues, but very low infectivity was detected in some tissues very long after inoculation (44-45 months). These results demonstrate that transmission of goat BSE is genotype dependent, and they highlight the pivotal protective effect of the K222 PRNP variant in the oral susceptibility of goats to BSE. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. The first report of prion-related protein gene (PRNT) polymorphisms in goat.

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    Kim, Yong-Chan; Jeong, Byung-Hoon

    2017-06-01

    Prion protein is encoded by the prion protein gene (PRNP). Polymorphisms of several members of the prion gene family have shown association with prion diseases in several species. Recent studies on a novel member of the prion gene family in rams have shown that prion-related protein gene (PRNT) has a linkage with codon 26 of prion-like protein (PRND). In a previous study, codon 26 polymorphism of PRND has shown connection with PRNP haplotype which is strongly associated with scrapie vulnerability. In addition, the genotype of a single nucleotide polymorphism (SNP) at codon 26 of PRND is related to fertilisation capacity. These findings necessitate studies on the SNP of PRNT gene which is connected with PRND. In goat, several polymorphism studies have been performed for PRNP, PRND, and shadow of prion protein gene (SPRN). However, polymorphism on PRNT has not been reported. Hence, the objective of this study was to determine the genotype and allelic distribution of SNPs of PRNT in 238 Korean native goats and compare PRNT DNA sequences between Korean native goats and several ruminant species. A total of five SNPs, including PRNT c.-114G > T, PRNT c.-58A > G in the upstream of PRNT gene, PRNT c.71C > T (p.Ala24Val) and PRNT c.102G > A in the open reading frame (ORF) and c.321C > T in the downstream of PRNT gene, were found in this study. All five SNPs of caprine PRNT gene in Korean native goat are in complete linkage disequilibrium (LD) with a D' value of 1.0. Interestingly, comparative sequence analysis of the PRNT gene revealed five mismatches between DNA sequences of Korean native goats and those of goats deposited in the GenBank. Korean native black goats also showed 5 mismatches in PRNT ORF with cattle. To the best of our knowledge, this is the first genetic research of the PRNT gene in goat.

  3. Different Molecular Mechanisms Mediate Direct or Glia-Dependent Prion Protein Fragment 90-231 Neurotoxic Effects in Cerebellar Granule Neurons.

    Science.gov (United States)

    Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Villa, Valentina; Corsaro, Alessandro; Nizzari, Mario; Robello, Mauro; Florio, Tullio

    2017-10-01

    Glia over-stimulation associates with amyloid deposition contributing to the progression of central nervous system neurodegenerative disorders. Here we analyze the molecular mechanisms mediating microglia-dependent neurotoxicity induced by prion protein (PrP)90-231, an amyloidogenic polypeptide corresponding to the protease-resistant portion of the pathological prion protein scrapie (PrP Sc ). PrP90-231 neurotoxicity is enhanced by the presence of microglia within neuronal culture, and associated to a rapid neuronal [Ca ++ ] i increase. Indeed, while in "pure" cerebellar granule neuron cultures, PrP90-231 causes a delayed intracellular Ca ++ entry mediated by the activation of NMDA receptors; when neuron and glia are co-cultured, a transient increase of [Ca ++ ] i occurs within seconds after treatment in both granule neurons and glial cells, then followed by a delayed and sustained [Ca ++ ] i raise, associated with the induction of the expression of inducible nitric oxide synthase and phagocytic NADPH oxidase. [Ca ++ ] i fast increase in neurons is dependent on the activation of multiple pathways since it is not only inhibited by the blockade of voltage-gated channel activity and NMDA receptors but also prevented by the inhibition of nitric oxide and PGE 2 release from glial cells. Thus, Ca ++ homeostasis alteration, directly induced by PrP90-231 in cerebellar granule cells, requires the activation of NMDA receptors, but is greatly enhanced by soluble molecules released by activated glia. In glia-enriched cerebellar granule cultures, the activation of inducible nitric oxide (iNOS) and NADPH oxidase represents the main mechanism of toxicity since their pharmacological inhibition prevented PrP90-231 neurotoxicity, whereas NMDA blockade by D(-)-2-amino-5-phosphonopentanoic acid is ineffective; conversely, in pure cerebellar granule cultures, NMDA blockade but not iNOS inhibition strongly reduced PrP90-231 neurotoxicity. These data indicate that amyloidogenic peptides

  4. Detecting animal by-product intake using stable isotope ratio mass spectrometry (IRMS).

    Science.gov (United States)

    da Silva, D A F; Biscola, N P; Dos Santos, L D; Sartori, M M P; Denadai, J C; da Silva, E T; Ducatti, C; Bicudo, S D; Barraviera, B; Ferreira, R S

    2016-11-01

    Sheep are used in many countries as food and for manufacturing bioproducts. However, when these animals consume animal by-products (ABP), which is widely prohibited, there is a risk of transmitting scrapie - a fatal prion disease in human beings. Therefore, it is essential to develop sensitive methods to detect previous ABP intake to select safe animals for producing biopharmaceuticals. We used stable isotope ratio mass spectrometry (IRMS) for 13 C and 15 N to trace animal proteins in the serum of three groups of sheep: 1 - received only vegetable protein (VP) for 89 days; 2 - received animal and vegetable protein (AVP); and 3 - received animal and vegetable protein with animal protein subsequently removed (AVPR). Groups 2 and 3 received diets with 30% bovine meat and bone meal (MBM) added to a vegetable diet (from days 16-89 in the AVP group and until day 49 in the AVPR group, when MBM was removed). The AVPR group showed 15 N equilibrium 5 days after MBM removal (54th day). Conversely, 15 N equilibrium in the AVP group occurred 22 days later (76th day). The half-life differed between these groups by 3.55 days. In the AVPR group, 15 N elimination required 53 days, which was similar to this isotope's incorporation time. Turnover was determined based on natural 15 N signatures. IRMS followed by turnover calculations was used to evaluate the time period for the incorporation and elimination of animal protein in sheep serum. The δ 13 C and δ 15 N values were used to track animal protein in the diet. This method is biologically and economically relevant for the veterinary field because it can track protein over time or make a point assessment of animal feed with high sensitivity and resolution, providing a low-cost analysis coupled with fast detection. Isotopic profiles could be measured throughout the experimental period, demonstrating the potential to use the method for traceability and certification assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. PrP P102L and Nearby Lysine Mutations Promote Spontaneous In Vitro Formation of Transmissible Prions.

    Science.gov (United States)

    Kraus, Allison; Raymond, Gregory J; Race, Brent; Campbell, Katrina J; Hughson, Andrew G; Anson, Kelsie J; Raymond, Lynne D; Caughey, Byron

    2017-11-01

    Accumulation of fibrillar protein aggregates is a hallmark of many diseases. While numerous proteins form fibrils by prion-like seeded polymerization in vitro , only some are transmissible and pathogenic in vivo To probe the structural features that confer transmissibility to prion protein (PrP) fibrils, we have analyzed synthetic PrP amyloids with or without the human prion disease-associated P102L mutation. The formation of infectious prions from PrP molecules in vitro has required cofactors and/or unphysiological denaturing conditions. Here, we demonstrate that, under physiologically compatible conditions without cofactors, the P102L mutation in recombinant hamster PrP promoted prion formation when seeded by minute amounts of scrapie prions in vitro Surprisingly, combination of the P102L mutation with charge-neutralizing substitutions of four nearby lysines promoted spontaneous prion formation. When inoculated into hamsters, both of these types of synthetic prions initiated substantial accumulation of prion seeding activity and protease-resistant PrP without transmissible spongiform encephalopathy (TSE) clinical signs or notable glial activation. Our evidence suggests that PrP's centrally located proline and lysine residues act as conformational switches in the in vitro formation of transmissible PrP amyloids. IMPORTANCE Many diseases involve the damaging accumulation of specific misfolded proteins in thread-like aggregates. These threads (fibrils) are capable of growing on the ends by seeding the refolding and incorporation of the normal form of the given protein. In many cases such aggregates can be infectious and propagate like prions when transmitted from one individual host to another. Some transmitted aggregates can cause fatal disease, as with human iatrogenic prion diseases, while other aggregates appear to be relatively innocuous. The factors that distinguish infectious and pathogenic protein aggregates from more innocuous ones are poorly understood

  6. The roles of the conserved tyrosine in the β2-α2 loop of the prion protein.

    Science.gov (United States)

    Huang, Danzhi; Caflisch, Amedeo

    2015-01-01

    Prions cause neurodegenerative diseases for which no cure exists. Despite decades of research activities the function of the prion protein (PrP) in mammalians is not known. Moreover, little is known on the molecular mechanisms of the self-assembly of the PrP from its monomeric state (cellular PrP, PrP(C)) to the multimeric state. The latter state includes the toxic species (scrapie PrP, PrP(Sc)) knowledge of which would facilitate the development of drugs against prion diseases. Here we analyze the role of a tyrosine residue (Y169) which is strictly conserved in mammalian PrPs. Nuclear magnetic resonance (NMR) spectroscopy studies of many mammalian PrP(C) proteins have provided evidence of a conformational equilibrium between a 3(10)-helical turn and a type I β turn conformation in the β2-α2 loop (residues 165-175). In vitro cell-free experiments of the seeded conversion of PrP(C) indicate that non-aromatic residues at position 169 reduce the formation of proteinase K-resistant PrP. Recent molecular dynamics (MD) simulations of monomeric PrP and several single-point mutants show that Y169 stabilizes the 3(10)-helical turn conformation more than single-point mutants at position 169 or residues in contact with it. In the 3(10)-helical turn conformation the hydrophobic and aggregation-prone segment 169-YSNQNNF-175 is buried and thus not-available for self-assembly. From the combined analysis of simulation and experimental results it emerges that Y169 is an aggregation gatekeeper with a twofold role. Mutations related to 3 human prion diseases are interpreted on the basis of the gatekeeper role in the monomeric state. Another potential role of the Y169 side chain is the stabilization of the ordered aggregates, i.e., reduction of frangibility of filamentous protofibrils and fibrils, which is likely to reduce the generation of toxic species.

  7. Wariant Choroby Creutzfeldta-Jakoba: aktualny stan wiedzy

    Directory of Open Access Journals (Sweden)

    James W. Ironside

    2011-04-01

    Full Text Available Choroby wywoływane przez priony obejmują: chorobę Creutzfeldta-Jakoba (Creutzfeldt-Jakob disease, CJD, kuru, chorobę Gerstmanna-Sträusslera-Scheinkera (GSS, śmiertelną rodzinną bezsenność (fatal familial insomnia, FFI u człowieka, scrapie (polska nieużywana nazwa: trzęsawka u owiec, kóz i muflonów, pasażowalną encefalopatię norek (transmissible mink encephalopathy, TME, encefalopatię gąbczastą bydła albo chorobę szalonych krów oraz przewlekłą chorobę wyniszczającą u jeleni (chronic wasting disease. Wariant choroby Creutzfeldta-Jakoba (vCJD jest to nowa choroba z grupy chorób wywoływanych przez priony spowodowana pasażem czynnika encefalopatii gąbczastej bydła (BSE. Przed wystąpieniem vCJD obserwowano pasaż BSE na kota domowego, pumę, ocelota, lwa i bizona. Większość przypadków vCJD obserwowano w Wielkiej Brytanii, mniejszą liczbę w 11 innych krajach. Wszystkie definitywne przypadki vCJD wystąpiły u homozygot Met Met w kodonie 129. genu kodującego PrP (PRNP. W wyniku zakażenia przez przewód pokarmowy czynnik infekcyjny vCJD replikuje się w tkance limfatycznej przed wystąpieniem objawów klinicznych choroby. Obecnie cztery prawdopodobne przypadki vCJD zidentyfikowano u biorców masy czerwonokrwinkowej uzyskanej od asymptomatycznych dawców, którzy następnie zmarli na vCJD. Ostatnio jeden przypadek prawdopodobnego pasażu vCJD poprzez koncentrat czynnika VIII wystąpił w Wielkiej Brytanii u starszego chorego z hemofilią. Ostatnie doniesienie o teście laboratoryjnym wykonywanym we krwi, który może być zastosowany do detekcji vCJD, wskazuje na możliwość identyfikacji zakażonych osób być może jeszcze przed wystąpieniem objawów klinicznych.

  8. The dangers of disease transmission by artificial insemination and embryo transfer.

    Science.gov (United States)

    Philpott, M

    1993-01-01

    This review summarizes the major infectious diseases of the three major agricultural species (cattle, sheep and pigs) and horses, and presents the evidence for and against the possibility of infectious agents being transmitted between animals via the venereal route or by the use of semen or early embryos in commercial artificial insemination (AI) or embryo transfer (ET). Cattle feature most prominently in the widespread distribution of frozen semen, and national and international organizations have set out guidelines to work towards disease-free bull studs with semen free from potential pathogens. With the control of major epizootic diseases, attention has been focused on such diseases as IBR, BVD and blue tongue, where clinical signs are rarely evident but the detection of virus in semen is of great importance. New information on the relevance of bacterial disease such as Mycobacterium paratuberculosis, campylobacteriosis and leptospirosis is reviewed, along with details of the mycoplasma and ureaplasma species of the bull's genital tract. Bovine spongiform encephalopathy (BSE) has attracted much research and semen is not regarded as a source of infection. New work on the pathogenesis of a number of diseases and the use of new biotechnology in diagnosis is included. The International Embryo Transfer Society (IETS) has encouraged a great deal of experimental work--much originating in Canada--on the risk of transmission of disease from donors to recipients via a 7-day-old blastocyst. There has been much success in demonstrating that with an approved protocol of handling the embryos, to date there is very little danger in disease transmission with both viruses and bacteria. The mycoplasma group appear more intractable and the role of BSE is still being evaluated. In sheep, scrapie, Brucella ovis infection and blue tongue feature in current work. In the pig there is a surge in international movement of pig semen, and Aujeszky's disease and the new so-called Blue Ear

  9. Exacerbation of experimental autoimmune encephalomyelitis in prion protein (PrPc-null mice: evidence for a critical role of the central nervous system

    Directory of Open Access Journals (Sweden)

    Gourdain Pauline

    2012-01-01

    Full Text Available Abstract Background The cellular prion protein (PrPc is a host-encoded glycoprotein whose transconformation into PrP scrapie (PrPSc initiates prion diseases. The role of PrPc in health is still obscure, but many candidate functions have been attributed to the protein, both in the immune and the nervous systems. Recent data show that experimental autoimmune encephalomyelitis (EAE is worsened in mice lacking PrPc. Disease exacerbation has been attributed to T cells that would differentiate into more aggressive effectors when deprived of PrPc. However, alternative interpretations such as reduced resistance of neurons to autoimmune insult and exacerbated gliosis leading to neuronal deficits were not considered. Method To better discriminate the contribution of immune cells versus neural cells, reciprocal bone marrow chimeras with differential expression of PrPc in the lymphoid or in the central nervous system (CNS were generated. Mice were subsequently challenged with MOG35-55 peptide and clinical disease as well as histopathology were compared in both groups. Furthermore, to test directly the T cell hypothesis, we compared the encephalitogenicity of adoptively transferred PrPc-deficient versus PrPc-sufficient, anti-MOG T cells. Results First, EAE exacerbation in PrPc-deficient mice was confirmed. Irradiation exacerbated EAE in all the chimeras and controls, but disease was more severe in mice with a PrPc-deleted CNS and a normal immune system than in the reciprocal construction. Moreover, there was no indication that anti-MOG responses were different in PrPc-sufficient and PrPc-deficient mice. Paradoxically, PrPc-deficient anti-MOG 2D2 T cells were less pathogenic than PrPc-expressing 2D2 T cells. Conclusions In view of the present data, it can be concluded that the origin of EAE exacerbation in PrPc-ablated mice resides in the absence of the prion protein in the CNS. Furthermore, the absence of PrPc on both neural and immune cells does not

  10. An ancient conserved role for prion protein in learning and memory

    Directory of Open Access Journals (Sweden)

    Patricia L. A. Leighton

    2018-01-01

    Full Text Available The misfolding of cellular prion protein (PrPC to form PrP Scrapie (PrPSc is an exemplar of toxic gain-of-function mechanisms inducing propagated protein misfolding and progressive devastating neurodegeneration. Despite this, PrPC function in the brain is also reduced and subverted during prion disease progression; thus understanding the normal function of PrPC in healthy brains is key. Disrupting PrPC in mice has led to a myriad of controversial functions that sometimes map onto disease symptoms, including a proposed role in memory or learning. Intriguingly, PrPC interaction with amyloid beta (Aβ oligomers at synapses has also linked its function to Alzheimer's disease and dementia in recent years. We set out to test the involvement of PrPC in memory using a disparate animal model, the zebrafish. Here we document an age-dependent memory decline in prp2−/− zebrafish, pointing to a conserved and ancient role of PrPC in memory. Specifically, we found that aged (3-year-old prp2−/− fish performed poorly in an object recognition task relative to age-matched prp2+/+ fish or 1-year-old prp2−/− fish. Further, using a novel object approach (NOA test, we found that aged (3-year-old prp2−/− fish approached the novel object more than either age-matched prp2+/+ fish or 1-year-old prp2−/− fish, but did not have decreased anxiety when we tested them in a novel tank diving test. Taken together, the results of the NOA and novel tank diving tests suggest an altered cognitive appraisal of the novel object in the 3-year-old prp2−/− fish. The learning paradigm established here enables a path forward to study PrPC interactions of relevance to Alzheimer's disease and prion diseases, and to screen for candidate therapeutics for these diseases. The findings underpin a need to consider the relative contributions of loss- versus gain-of-function of PrPC during Alzheimer's and prion diseases, and have implications upon the prospects of several

  11. Assessment of the PrPc Amino-Terminal Domain in Prion Species Barriers.

    Science.gov (United States)

    Davenport, Kristen A; Henderson, Davin M; Mathiason, Candace K; Hoover, Edward A

    2016-12-01

    Chronic wasting disease (CWD) in cervids and bovine spongiform encephalopathy (BSE) in cattle are prion diseases that are caused by the same protein-misfolding mechanism, but they appear to pose different risks to humans. We are interested in understanding the differences between the species barriers of CWD and BSE. We used real-time, quaking-induced conversion (RT-QuIC) to model the central molecular event in prion disease, the templated misfolding of the normal prion protein, PrP c , to a pathogenic, amyloid isoform, scrapie prion protein, PrP Sc We examined the role of the PrP c amino-terminal domain (N-terminal domain [NTD], amino acids [aa] 23 to 90) in cross-species conversion by comparing the conversion efficiency of various prion seeds in either full-length (aa 23 to 231) or truncated (aa 90 to 231) PrP c We demonstrate that the presence of white-tailed deer and bovine NTDs hindered seeded conversion of PrP c , but human and bank vole NTDs did the opposite. Additionally, full-length human and bank vole PrP c s were more likely to be converted to amyloid by CWD prions than were their truncated forms. A chimera with replacement of the human NTD by the bovine NTD resembled human PrP c The requirement for an NTD, but not for the specific human sequence, suggests that the NTD interacts with other regions of the human PrP c to increase promiscuity. These data contribute to the evidence that, in addition to primary sequence, prion species barriers are controlled by interactions of the substrate NTD with the rest of the substrate PrP c molecule. We demonstrate that the amino-terminal domain of the normal prion protein, PrP c , hinders seeded conversion of bovine and white-tailed deer PrP c s to the prion forms, but it facilitates conversion of the human and bank vole PrP c s to the prion forms. Additionally, we demonstrate that the amino-terminal domain of human and bank vole PrP c s requires interaction with the rest of the molecule to facilitate conversion by CWD

  12. Protein A磁珠检测朊病毒方法的建立%The foundation of Protein A magnetism to detect Prion assay

    Institute of Scientific and Technical Information of China (English)

    李奇; 杨阳; 吕鹏; 宋博翠; 白宗瑞; 陈志宝

    2009-01-01

    建立Protein A磁珠法检测朊病毒,将朊病毒抗体IH2包被后的Protein A磁珠与蛋白酶K消化过的攻毒小鼠脑组织匀浆液混合,经免疫沉淀缓冲液温和洗脱杂蛋白,再经0.2 M甘氨酸将目的蛋白洗脱并且利用聚丙酰胺凝胶电泳检测.通过聚丙酰胺凝胶电泳检测出25 KD的目的蛋白带,经与正常未消化的朊蛋白条带相比较,证实检测出朊病毒.Protein A磁珠具有高效特异的与抗体IgG结合的特点,与多克隆抗体混合后可有效结合IgG.该方法较免疫组织化学和Western-blot技术简便快速,且磁珠可以回收再使用,使成本低廉.%Objective The country need the fast and effective detection for Prion asthe high risk country where Scrapie and BSE may bresk out. The common assay of Western-Blot and Immunohistochemistry consume a long time and the associated experience is needed. Protein A magnetism has the feature of binding IgG differential.h could bind the IgG adequately,when mixing with polyclonal antibody.After intermixing with brain tissue protein digested by protein kinase, Prion could easily elute from Protein A magnetism.Interest protein band is 25KD through SDS-PAGE. When definiting the molecular weight of Priori,the result of detection is educed by SDS-PAGE electrophoresis. The assay is more handier and faster than common assay. The magnetism can reclaim and reuse,which reduce the cost.The assay of detection is a innovation and many branches could generally applicated it.

  13. Reflections on a half-century in the field of transmissible spongiform encephalopathy.

    Science.gov (United States)

    Brown, Paul

    2009-01-01

    The subject of transmissible spongiform encephalopathy may properly be said to have begun with the experimental transmission of scrapie by Cuillé and Chelle in 1936, although Creutzfeldt and Jakob had described the disease that bears their names in 1920-21. Thirty more years passed before the human disease was also shown to be transmissible, in 1966, and the following half century has seen the field move from classical biology to molecular biology and genetics, and from 'slow virus' to host-encoded 'prion' protein. Because nothing is more important to the research scientist than the process of seeing a problem and devising ways of solving it, and because we live and die by our publications, as much care should be given to these vehicles of our work and reputations as to the research itself. Four aspects have been chosen for comment: authorship, abbreviations, data presentation, and references. In addition to the 'science of research' there are several 'para-scientific' activities that may be categorized as 'the politics of research', which include administrative duties, committees (e.g., scientific meetings, grant organizations), journal/book editing, peer reviewing, and public relations Many young scientists are either unaware or dismissive of the importance of these 'scientific distractions', but their potential for influencing the direction of a field of research becomes increasingly evident as careers unfold. They are subject to uses and abuses, and some guidance and examples are given by way of illustration, particular attention being paid to the process of manuscript review which, because of its anonymity, is the most vulnerable to abuse. As public and government interest in prions wanes in parallel with the disappearance of iatrogenic and variant Creutzfeldt-Jakob disease, the flow of money to sustain research is in evident jeopardy. With an uncertain future, it nevertheless seems possible that one of two things may breathe new life into the field: either

  14. An autopsied case of MM1 + MM2-cortical with thalamic-type sporadic Creutzfeldt-Jakob disease presenting with hyperintensities on diffusion-weighted MRI before clinical onset.

    Science.gov (United States)

    Iwasaki, Yasushi; Mori, Keiko; Ito, Masumi; Mimuro, Maya; Kitamoto, Tetsuyuki; Yoshida, Mari

    2017-02-01

    A 78-year-old Japanese man presented with rapidly progressive dementia and gait disturbances. Eight months before the onset of clinical symptoms, diffusion-weighted magnetic resonance imaging (DWI) demonstrated hyperintensities in the right temporal, right parietal and left medial occipital cortices. Two weeks after symptom onset, DWI showed extensive hyperintensity in the bilateral cerebral cortex, with regions of higher brightness that existed prior to symptom onset still present. Four weeks after clinical onset, periodic sharp wave complexes were identified on an electroencephalogram. Myoclonus was observed 8 weeks after clinical onset. The patient reached an akinetic mutism state and died 5 months after onset. Neuropathological examination showed widespread cerebral neocortical involvement of fine vacuole-type spongiform changes with large confluent vacuole-type spongiform changes. Spongiform degeneration with neuron loss and hypertrophic astrocytosis was also observed in the striatum and medial thalamus. The inferior olivary nucleus showed severe neuron loss with hypertrophic astrocytosis. Prion protein (PrP) immunostaining showed widespread synaptic-type PrP deposition with perivacuolar-type PrP deposition in the cerebral neocortex. Mild to moderate PrP deposition was also observed extensively in the basal ganglia, thalamus, cerebellum and brainstem, but it was not apparent in the inferior olivary nucleus. PrP gene analysis showed no mutations, and polymorphic codon 129 showed methionine homozygosity. Western blot analysis of protease-resistant PrP showed both type 1 scrapie type PrP (PrP Sc ) and type 2 PrP Sc . Based on the relationship between the neuroimaging and pathological findings, we speculated that cerebral cortical lesions with large confluent vacuoles and type 2 PrP Sc would show higher brightness and continuous hyperintensity on DWI than those with fine vacuoles and type 1 PrP Sc . We believe the present patient had a combined form of MM1

  15. Removal of transmissible spongiform encephalopathy prion from large volumes of cell culture media supplemented with fetal bovine serum by using hollow fiber anion-exchange membrane chromatography.

    Science.gov (United States)

    Chou, Ming Li; Bailey, Andy; Avory, Tiffany; Tanimoto, Junji; Burnouf, Thierry

    2015-01-01

    Cases of variant Creutzfeldt-Jakob disease in people who had consumed contaminated meat products from cattle with bovine spongiform encephalopathy emphasize the need for measures aimed at preventing the transmission of the pathogenic prion protein (PrPSc) from materials derived from cattle. Highly stringent scrutiny is required for fetal bovine serum (FBS), a growth-medium supplement used in the production of parenteral vaccines and therapeutic recombinant proteins and in the ex vivo expansion of stem cells for transplantation. One such approach is the implementation of manufacturing steps dedicated to removing PrPSc from materials containing FBS. We evaluated the use of the QyuSpeed D (QSD) adsorbent hollow-fiber anion-exchange chromatographic column (Asahi Kasei Medical, Tokyo, Japan) for the removal of PrPSc from cell culture media supplemented with FBS. We first established that QSD filtration had no adverse effect on the chemical composition of various types of culture media supplemented with 10% FBS or the growth and viability characteristics of human embryonic kidney (HEK293) cells, baby hamster kidney (BHK-21) cells, African green monkey kidney (Vero) cells, and Chinese hamster ovary (CHO-k1) cells propagated in the various culture-medium filtrates. We used a 0.6-mL QSD column for removing PrPSc from up to 1000 mL of Dulbecco's modified Eagle's medium containing 10% FBS previously spiked with the 263K strain of hamster-adapted scrapie. The Western blot analysis, validated alongside an infectivity assay, revealed that the level of PrPSc in the initial 200mL flow-through was reduced by 2.5 to > 3 log10, compared with that of the starting material. These results indicate that QSD filtration removes PrPSc from cell culture media containing 10% FBS, and demonstrate the ease with which QSD filtration can be implemented in at industrial-scale to improve the safety of vaccines, therapeutic recombinant proteins, and ex vivo expanded stem cells produced using growth

  16. Gene-based technologies for livestock industries in the 3rd millennium

    International Nuclear Information System (INIS)

    Cunningham, E.P.

    2005-01-01

    (e.g. scrapie) with the genotype of the animal calls for the application of DNA technologies. Following the BSE epidemic in Europe, safety of livestock-derived foods is high on research and regulatory agendas. DNA techniques are already in use for tracking of sources of Salmonella enterica and Escherichia coli outbreaks, as well as for traceability of product in the food chain. Finally, gene-based technologies can facilitate the measurement and conservation of genetic diversity in animal populations. (author)

  17. [Basic research on BSE transmission to people].

    Science.gov (United States)

    Bodemer, W; Kaup, F J

    2002-08-01

    Prion diseases of animal and man belong to neurological diseases with amyloidal deposition of the respective proteins. As to prion disease, the cellular prionprotein is in its abnormal isoform(s) an essential component of prionprotein aggregates found in affected tissue. In contrast to all neurodegenerative diseases like Morbus Alzheimer or Huntington's disease, prion diseases are transmissible. Therefore, prion diseases were designated Transmissible Spongiform Encephalopathies (TSE). The diseases are well known since decades. Scrapie was first described around 1750, a BSE case was reported in the 1850, most likely a misdiagnosis, and in 1920/1930 the human Creutzfeldt-Jakob disease (CJD) had been described. Transmission of CJD i.e. Kuru had been suspected in the early 1950s and erronously classified as slow virus disease. The CJD transmission posed a problem to humans when transplants from CJD cases were used for treatment. Fortunately, these iatrogenic transmissions remained limited. But with the advent of BSE and appearance of variant CJD cases in the UK and some places in Europe scientists suspected that transmission from cattle to man could have happened. From animal models we know of successful transmission via several routes. Species barriers do not completely prevent transmission. Rather transmission barriers might exist controlling individual susceptibility against prions. Modes of transmission, susceptibility for transmission, identification of receptor molecules as well as molecular mechanisms of the transmission process are intensely investigated. Current knowledge let us to assume that inapparent stages of prion infection pretend a (not existing) species barrier. This inapparent infection preceeds overt disease and, thus, most re-search focuses on the development of highly sensitive assay systems for detection of minute amounts of pathological prionprotein in suspected cases. Inapparence also should warn us to underestimate BSE or human vCJD cases; at

  18. Distinct pathological phenotypes of Creutzfeldt-Jakob disease in recipients of prion-contaminated growth hormone.

    Science.gov (United States)

    Cali, Ignazio; Miller, Cathleen J; Parisi, Joseph E; Geschwind, Michael D; Gambetti, Pierluigi; Schonberger, Lawrence B

    2015-06-25

    The present study compares the clinical, pathological and molecular features of a United States (US) case of growth hormone (GH)-associated Creutzfeldt-Jakob disease (GH-CJD) (index case) to those of two earlier referred US cases of GH-CJD and one case of dura mater (d)-associated CJD (dCJD). All iatrogenic CJD (iCJD) subjects were methionine (M) homozygous at codon 129 (129MM) of the prion protein (PrP) gene and had scrapie prion protein (PrP(Sc)) type 1 (iCJDMM1). The index subject presented with ataxia, weight loss and changes in the sleep pattern about 38 years after the midpoint of GH treatment. Autopsy examination revealed a neuropathological phenotype reminiscent of both sCJDMV2-K (a sporadic CJD subtype in subjects methionine/valine heterozygous at codon 129 with PrP(Sc) type 2 and the presence of kuru plaques) and variant CJD (vCJD). The two earlier cases of GH-CJDMM1 and the one of dCJDMM1 were associated with neuropathological phenotypes that differed from that of the index case mainly because they lacked PrP plaques. The phenotype of the earlier GH-CJDMM1 cases shared several, but not all, characteristics with sCJDMM1, whereas dCJDMM1 was phenotypically indistinguishable from sCJDMM1. Two distinct groups of dCJDMM1 have also been described in Japan based on clinical features, the presence or absence of PrP plaques and distinct PK-resistant PrP(Sc) (resPrP(Sc)) electrophoretic mobilities. The resPrP(Sc) electrophoretic mobility was, however, identical in our GH-CJDMM1 and dCJDMM1 cases, and matched that of sCJDMM1. Our study shows that receipt of prion-contaminated GH can lead to a prion disease with molecular features (129MM and PrP(Sc) type 2) and phenotypic characteristics that differ from those of sporadic prion disease (sCJDMM1), a difference that may reflect adaptation of "heterologous" prion strains to the 129MM background.

  19. Iatrogenic Creutzfeldt-Jakob disease with Amyloid-β pathology: an international study.

    Science.gov (United States)

    Cali, Ignazio; Cohen, Mark L; Haїk, Stéphane; Parchi, Piero; Giaccone, Giorgio; Collins, Steven J; Kofskey, Diane; Wang, Han; McLean, Catriona A; Brandel, Jean-Philippe; Privat, Nicolas; Sazdovitch, Véronique; Duyckaerts, Charles; Kitamoto, Tetsuyuki; Belay, Ermias D; Maddox, Ryan A; Tagliavini, Fabrizio; Pocchiari, Maurizio; Leschek, Ellen; Appleby, Brian S; Safar, Jiri G; Schonberger, Lawrence B; Gambetti, Pierluigi

    2018-01-08

    The presence of pathology related to the deposition of amyloid-β (Aβ) has been recently reported in iatrogenic Creutzfeldt-Jakob disease (iCJD) acquired from inoculation of growth hormone (GH) extracted from human cadaveric pituitary gland or use of cadaveric dura mater (DM) grafts.To investigate this phenomenon further, a cohort of 27 iCJD cases - 21 with adequate number of histopathological sections - originating from Australia, France, Italy, and the Unites States, were examined by immunohistochemistry, amyloid staining, and Western blot analysis of the scrapie prion protein (PrP Sc ), and compared with age-group matched cases of sporadic CJD (sCJD), Alzheimer disease (AD) or free of neurodegenerative diseases (non-ND).Cases of iCJD and sCJD shared similar profiles of proteinase K-resistant PrP Sc with the exception of iCJD harboring the "MMi" phenotype. Cerebral amyloid angiopathy (CAA), either associated with, or free of, Thioflavin S-positive amyloid core plaques (CP), was observed in 52% of 21 cases of iCJD, which comprised 37.5% and 61.5% of the cases of GH- and DM-iCJD, respectively. If only cases younger than 54 years were considered, Aβ pathology affected 41%, 2% and 0% of iCJD, sCJD and non-ND, respectively. Despite the patients' younger age CAA was more severe in iCJD than sCJD, while Aβ diffuse plaques, in absence of Aβ CP, populated one third of sCJD. Aβ pathology was by far most severe in AD. Tau pathology was scanty in iCJD and sCJD.In conclusion, (i) despite the divergences in the use of cadaveric GH and DM products, our cases combined with previous studies showed remarkably similar iCJD and Aβ phenotypes indicating that the occurrence of Aβ pathology in iCJD is a widespread phenomenon, (ii) CAA emerges as the hallmark of the Aβ phenotype in iCJD since it is observed in nearly 90% of all iCJD with Aβ pathology reported to date including ours, and it is shared by GH- and DM-iCJD, (iii) although the contributions to Aβ pathology of other

  20. Genomic DNA extraction protocols from ovine hair

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    Jennifer Nonato da Silva Prate

    2013-12-01

    was transferred to another microtube, and the DNA was precipitated in the presence of 0.3 M sodium acetate (1/10 volume and 1 mL ethanol at -20°C for 6 hours. Then the samples were centrifuged at 12,000 rpm, 4°C for 30 minutes. The precipitate after drying was resuspended in 50 µL of ultrapure water. The second protocol was standardized by the Laboratory of Biochemistry and Genetics, FMRP - USP, whose procedures are described below: from each animal was used about 3-4 hairs, containing the hair bulb. This sample was transferred to a microtube containing 100 mL of buffer (20 mM Tris HCl, 50 mM KCl, 2.5 mM MgCl2 and 0.5% Tween 20 and 1 µL of proteinase K [10 mg mL-1], and then incubated at 60°C with shaking (160 rpm for 45 minutes. For denaturation of the proteinase-K, the microtubes were incubated at 95°C for 10 minutes. After extraction by both methods, the DNA was quantified and subjected to PCR using specific primers for Prion gene amplification, associated to the Scrapie. The gel electrophoresis in agarose 1% revealed that the DNA obtained by the two protocols enabled amplification of the fragment of 198 pb, as expected. The amplification product was digested by the restriction enzyme AvaII at 37°C for 3 hours, and subjected to electrophoresis on polyacrylamide 10% gel (49:1 resulted in two fragments of 106 and 92 bp, as expected. Based on these results we conclude that both extraction methods allow obtaining DNA samples in quantity and quality satisfactory for PCR-RFLP analysis of Scrapie gene, although the latter was more efficient and economical, non-toxic and use smaller amounts of sample per animal.

  1. PrP Knockout Cells Expressing Transmembrane PrP Resist Prion Infection.

    Science.gov (United States)

    Marshall, Karen E; Hughson, Andrew; Vascellari, Sarah; Priola, Suzette A; Sakudo, Akikazu; Onodera, Takashi; Baron, Gerald S

    2017-01-15

    Glycosylphosphatidylinositol (GPI) anchoring of the prion protein (PrP C ) influences PrP C misfolding into the disease-associated isoform, PrP res , as well as prion propagation and infectivity. GPI proteins are found in cholesterol- and sphingolipid-rich membrane regions called rafts. Exchanging the GPI anchor for a nonraft transmembrane sequence redirects PrP C away from rafts. Previous studies showed that nonraft transmembrane PrP C variants resist conversion to PrP res when transfected into scrapie-infected N2a neuroblastoma cells, likely due to segregation of transmembrane PrP C and GPI-anchored PrP res in distinct membrane environments. Thus, it remained unclear whether transmembrane PrP C might convert to PrP res if seeded by an exogenous source of PrP res not associated with host cell rafts and without the potential influence of endogenous expression of GPI-anchored PrP C To further explore these questions, constructs containing either a C-terminal wild-type GPI anchor signal sequence or a nonraft transmembrane sequence containing a flexible linker were expressed in a cell line derived from PrP knockout hippocampal neurons, NpL2. NpL2 cells have physiological similarities to primary neurons, representing a novel and advantageous model for studying transmissible spongiform encephalopathy (TSE) infection. Cells were infected with inocula from multiple prion strains and in different biochemical states (i.e., membrane bound as in brain microsomes from wild-type mice or purified GPI-anchorless amyloid fibrils). Only GPI-anchored PrP C supported persistent PrP res propagation. Our data provide strong evidence that in cell culture GPI anchor-directed membrane association of PrP C is required for persistent PrP res propagation, implicating raft microdomains as a location for conversion. Mechanisms of prion propagation, and what makes them transmissible, are poorly understood. Glycosylphosphatidylinositol (GPI) membrane anchoring of the prion protein (PrP C

  2. Ayer, Hoy y Mañana, La Teoría del Prión.

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    Gabriel Toro González

    2004-03-01

    Full Text Available

    (Reproducido con autorización de Acta Neurológica Colombiana Vol. 18 No. 4, 2002.

    Introducción

    La creencia mejor respaldada actualmente nos indica que existe un grupo de enfermedades causadas por anormalidades en el procesamiento de las proteínas. En la década 1950-1960 D. Carleton Gajdusek y Vincent Zigas comenzaron a estudiar en Nueva Guinea una enfermedad fatal del sistema nervioso que se conoce con el nombre de Kuru que estaba diezmando a la tribu Fore, comunidad de unos 12.000 nativos (Figura 1. Gajdusek y Zigas observaron que el Kuru no correspondía a ningún modelo genético conocido y con la colaboración del antropólogo R. Glasse pensaron que el canibalismo ritual practicado por los Fore podría ser la causa de la transmisión de esta enfermedad, lo cual resultó cierto porque el Kuru prácticamente desapareció tras tres décadas de abolidos estos hábitos.

    Desde el primer momento se notó que el Kuru tenía características comunes con el Scrapie y que había semejanza entre estas dos entidades y la enfermedad de Creutzfeldt-Jakob (ECJ, una demencia de progresión rápida, no limitada geográficamente, descrita a principios del siglo XX, las tres aparentemente causadas por infecciones virales lentas con largos períodos de incubación medibles en años y un avance irreversible de los síntomas.

    Este pensamiento, por supuesto, se apoyaba en la afirmación formulada en 1939 por Mc Farlane Burnet de un posible mecanismo de acción lenta o temperada, inicialmente ejemplificada en los virus Herpes y en la propuesta que unos 15 años más tarde hiciera el veterinario islandés B. Sigurdsson de llamar Enfermedades Virales Lentas a las entidades que exhibieran tal comportamiento. Philip Duffy y colaboradores en la Universidad de Columbia, en 1974 comunican la primera observación de transmisión de la demencia de Creutzfeldt –Jakob de humano a humano a través de un injerto de c