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1.
Background
Transmissible agents involved in prion diseases differ in their capacities to target different regions of the central nervous system and lymphoid tissues, which are also host-dependent.Methodology/Principal Findings
Protease-resistant prion protein (PrPres) was analysed by Western blot in the spleen of transgenic mice (TgOvPrP4) that express the ovine prion protein under the control of the neuron-specific enolase promoter, after infection by intra-cerebral route with a variety of transmissible spongiform encephalopathies (TSEs) from cattle and small ruminants. Splenic PrPres was consistently detected in classical BSE and in most natural scrapie sources, the electrophoretic pattern showing similar features to that of cerebral PrPres. However splenic PrPres was not detected in L-type BSE and TME-in-cattle, or in the CH1641 experimental scrapie isolate, indicating that some TSE strains showed reduced splenotropism in the ovine transgenic mice. In contrast with CH1641, PrPres was also consistently detected in the spleen of mice infected with six natural “CH1641-like” scrapie isolates, but then showed clearly different molecular features from those identified in the brains (unglycosylated PrPres at ∼18 kDa with removal of the 12B2 epitope) of ovine transgenic mice or of sheep. These features included different cleavage of the main PrPres cleavage product (unglycosylated PrPres at ∼19 kDa with preservation of the 12B2 epitope) and absence of the additional C-terminally cleaved PrPres product (unglycosylated form at ∼14 kDa) that was detected in the brain.Conclusion/Significance
Studies in a transgenic mouse model expressing the sheep prion protein revealed different capacities of ruminant prions to propagate in the spleen. They showed unexpected features in “CH1641-like” ovine scrapie suggesting that such isolates contain mixed conformers with distinct capacities to propagate in the brain or lymphoid tissues of these mice. 相似文献2.
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. 相似文献
3.
Sheep prions with molecular properties intermediate between classical scrapie,BSE and CH1641–scrapie
Jan PM Langeveld Jorg G Jacobs Jo HF Erkens Thierry Baron Olivier Andréoletti Takahashi Yokoyama 《朊病毒》2014,8(4):296-305
Efforts to differentiate bovine spongiform encephalopathy (BSE) from scrapie in prion infected sheep have resulted in effective methods to decide about the absence of BSE. In rare instances uncertainties remain due to assumptions that BSE, classical scrapie and CH1641–a rare scrapie variant–could occur as mixtures. In field samples including those from fallen stock, triplex Western blotting analyses of variations in the molecular properties of the proteinase K resistant part of the disease‑associated form of prion protein (PrPres) represents a powerful tool for quick discrimination purposes. In this study we examined 7 deviant ovine field cases of scrapie for some typical molecular aspects of PrPres found in CH1641‑scrapie, classical scrapie and BSE. One case was most close to scrapie with respect to molecular mass of its non-glycosylated fraction and N-terminally located 12B2‑epitope content. Two cases were unlike classical scrapie but too weak to differentiate between BSE or CH1641. The other 4 cases appeared intermediate between scrapie and CH1641 with a reduced molecular mass and 12B2‑epitope content, together with the characteristic presence of a second PrPres population. The existence of these 2 PrPres populations was further confirmed through deglycosylation by PNGaseF. The findings indicate that discriminatory diagnosis between classical scrapie, CH1641 and BSE can remain inconclusive with current biochemical methods. Whether such intermediate cases represent mixtures of TSE strains should be further investigated e.g. in bioassays with rodent lines that are varying in their susceptibility or other techniques suitable for strain typing. 相似文献
4.
Laura Pirisinu Romolo Nonno Elena Esposito Sylvie L. Benestad Pierluigi Gambetti Umberto Agrimi Wen-Quan Zou 《PloS one》2013,8(6)
Prion diseases are classically characterized by the accumulation of pathological prion protein (PrPSc) with the protease resistant C-terminal fragment (PrPres) of 27–30 kDa. However, in both humans and animals, prion diseases with atypical biochemical features, characterized by PK-resistant PrP internal fragments (PrPres) cleaved at both the N and C termini, have been described. In this study we performed a detailed comparison of the biochemical features of PrPSc from atypical prion diseases including human Gerstmann-Sträussler-Scheinker disease (GSS) and variably protease-sensitive prionopathy (VPSPr) and in small ruminant Nor98 or atypical scrapie. The kinetics of PrPres production and its cleavage sites after PK digestion were analyzed, along with the PrPSc conformational stability, using a new method able to characterize both protease-resistant and protease-sensitive PrPSc components. All these PrPSc types shared common and distinctive biochemical features compared to PrPSc from classical prion diseases such as sporadic Creutzfeldt-Jakob disease and scrapie. Notwithstanding, distinct biochemical signatures based on PrPres cleavage sites and PrPSc conformational stability were identified in GSS A117V, GSS F198S, GSS P102L and VPSPr, which allowed their specific identification. Importantly, the biochemical properties of PrPSc from Nor98 and GSS P102L largely overlapped, but were distinct from the other human prions investigated. Finally, our study paves the way towards more refined comparative approaches to the characterization of prions at the animal–human interface. 相似文献
5.
Anne-Ga?lle Biacabe Jorg G Jacobs Anna Bencsik Jan PM Langeveld Thierry GM Baron 《朊病毒》2007,1(1):61-68
We previously reported that some cattle affected by bovine spongiform encephalopathy (BSE) showed distinct molecular features of the protease-resistant prion protein (PrPres) in Western blot, with a 1–2 kDa higher apparent molecular mass of the unglycosylated PrPres associated with labelling by antibodies against the 86–107 region of the bovine PrP protein (H-type BSE). By Western blot analyses of PrPres, we now showed that the essential features initially described in cattle were observed with a panel of different antibodies and were maintained after transmission of the disease in C57Bl/6 mice. In addition, antibodies against the C-terminal region of PrP revealed a second, more C-terminally cleaved, form of PrPres (PrPres #2), which, in unglycosylated form, migrated as a ≈ 14 kDa fragment. Furthermore, a PrPres fragment of ≈7 kDa, which was not labelled by C-terminus-specific antibodies and was thus presumed to be a product of cleavage at both N- and C-terminal sides of PrP protein, was also detected. Both PrPres #2 and ≈7 kDa PrPres were detected in cattle and in C57Bl/6 infected mice. These complex molecular features are reminiscent of findings reported in human prion diseases. This raises questions regarding the respective origins and pathogenic mechanisms in prion diseases of animals and humans.Key Words: prion, BSE, Creutzfeldt-Jakob, Gerstmann-Sträussler-Scheinker, Western blot, amyloid 相似文献
6.
Helen C. Rees Ben C. Maddison Jonathan P. Owen Garry C. Whitelam Kevin C. Gough 《Molecular biotechnology》2009,41(3):254-262
Reagents that can precipitate the disease-associated prion protein (PrPSc) are vital for the development of high sensitivity tests to detect low levels of this disease marker in biological material.
Here, a range of minerals are shown to precipitate both ovine cellular prion protein (PrPC) and ovine scrapie PrPSc. The precipitation of prion protein with silicon dioxide is unaffected by PrPSc strain or host species and the method can be used to precipitate bovine BSE. This method can reliably concentrate protease-resistant
ovine PrPSc (PrPres) derived from 1.69 μg of brain protein from a clinically infected animal diluted into either 50 ml of buffer or 15 ml of
plasma. The introduction of a SiO2 precipitation step into the immunological detection of PrPres increased detection sensitivity by over 1,500-fold. Minerals such as SiO2 are readily available, low cost reagents with generic application to the concentration of diseases-associated prion proteins. 相似文献
7.
Distinct molecular phenotypes in bovine prion diseases 总被引:6,自引:0,他引:6
Bovine spongiform encephalopathy (BSE) in cattle, the most likely cause of variant Creutzfeldt–Jakob disease in humans, is thought to be caused by a unique infectious agent, with stable features, even when transmitted to other species. Here, we show the existence of an atypical molecular phenotype among cattle diagnosed with BSE in France. Following western blot analysis, three cases showed unusual features of the electrophoretic profiles of the protease-resistant prion protein (PrPres) accumulating in the brain. The PrPres patterns were similar in these three atypical cases, showing a higher molecular mass of unglycosylated PrPres and strong labelling by P4 monoclonal antibody compared to 55 typical BSE cases. This finding suggests either some phenotypic modifications of PrPres following infection by the BSE agent or the existence of alternative origins of such diseases in cattle. 相似文献
8.
Enric Vidal Natalia Fernández-Borges Belén Pintado Hasier Era?a Montserrat Ordó?ez Mercedes Márquez Francesca Chianini Dolors Fondevila Manuel A. Sánchez-Martín Olivier Andreoletti Mark P. Dagleish Martí Pumarola Joaquín Castilla 《PLoS pathogens》2015,11(8)
Interspecies transmission of prions is a well-established phenomenon, both experimentally and under field conditions. Upon passage through new hosts, prion strains have proven their capacity to change their properties and this is a source of strain diversity which needs to be considered when assessing the potential risks associated with consumption of prion contaminated protein sources. Rabbits were considered for decades to be a prion resistant species until proven otherwise recently. To determine the extent of rabbit susceptibility to prions and to assess the effects of passage of different prion strains through this species a transgenic mouse model overexpressing rabbit PrPC was developed (TgRab). Intracerebral challenges with prion strains originating from a variety of species including field isolates (ovine SSBP/1 scrapie, Nor98- scrapie; cattle BSE, BSE-L and cervid CWD), experimental murine strains (ME7 and RML) and experimentally obtained ruminant (sheepBSE) and rabbit (de novo NZW) strains were performed. On first passage TgRab were susceptible to the majority of prions (Cattle BSE, SheepBSE, BSE-L, de novo NZW, ME7 and RML) tested with the exception of SSBP/1 scrapie, CWD and Nor98 scrapie. Furthermore, TgRab were capable of propagating strain-specific features such as differences in incubation periods, histological brain lesions, abnormal prion (PrPd) deposition profiles and proteinase-K (PK) resistant western blotting band patterns. Our results confirm previous studies proving that rabbits are not resistant to prion infection and show for the first time that rabbits are susceptible to PrPd originating in a number of other species. This should be taken into account when choosing protein sources to feed rabbits. 相似文献
9.
Lars Luers Oliver Bannach Jan St?hr Michael Marius W?rdehoff Martin Wolff Luitgard Nagel-Steger Detlev Riesner Dieter Willbold Eva Birkmann 《PloS one》2013,8(8)
Prion diseases are transmissible spongiform encephalopathies in humans and animals, including scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, chronic wasting disease (CWD) in deer, and Creutzfeldt-Jakob disease (CJD) in humans. The hallmark of prion diseases is the conversion of the host-encoded prion protein (PrPC) to its pathological isoform PrPSc, which is accompanied by PrP fibrillation. Transmission is not restricted within one species, but can also occur between species. In some cases a species barrier can be observed that results in limited or unsuccessful transmission. The mechanism behind interspecies transmissibility or species barriers is not completely understood. To analyse this process at a molecular level, we previously established an in vitro fibrillation assay, in which recombinant PrP (recPrP) as substrate can be specifically seeded by PrPSc as seed. Seeding with purified components, with no additional cellular components, is a direct consequence of the “prion-protein-only” hypothesis. We therefore hypothesise, that the species barrier is based on the interaction of PrPC and PrPSc. Whereas in our earlier studies, the interspecies transmission in animal systems was analysed, the focus of this study lies on the transmission from animals to humans. We therefore combined seeds from species cattle, sheep and deer (BSE, scrapie, CWD) with human recPrP. Homologous seeding served as a control. Our results are consistent with epidemiology, other in vitro aggregation studies, and bioassays investigating the transmission between humans, cattle, sheep, and deer. In contrast to CJD and BSE seeds, which show a seeding activity we can demonstrate a species barrier for seeds from scrapie and CWD in vitro. We could show that the seeding activity and therewith the molecular interaction of PrP as substrate and PrPSc as seed is sufficient to explain the phenomenon of species barriers. Therefore our data supports the hypothesis that CWD is not transmissible to humans. 相似文献
10.
Philippe Tixador La?titia Herzog Fabienne Reine Emilie Jaumain Jér?me Chapuis Annick Le Dur Hubert Laude Vincent Béringue 《PLoS pathogens》2010,6(4)
Prions are unconventional infectious agents thought to be primarily composed of PrPSc, a multimeric misfolded conformer of the ubiquitously expressed host-encoded prion protein (PrPC). They cause fatal neurodegenerative diseases in both animals and humans. The disease phenotype is not uniform within species, and stable, self-propagating variations in PrPSc conformation could encode this ‘strain’ diversity. However, much remains to be learned about the physical relationship between the infectious agent and PrPSc aggregation state, and how this varies according to the strain. We applied a sedimentation velocity technique to a panel of natural, biologically cloned strains obtained by propagation of classical and atypical sheep scrapie and BSE infectious sources in transgenic mice expressing ovine PrP. Detergent-solubilized, infected brain homogenates were used as starting material. Solubilization conditions were optimized to separate PrPSc aggregates from PrPC. The distribution of PrPSc and infectivity in the gradient was determined by immunoblotting and mouse bioassay, respectively. As a general feature, a major proteinase K-resistant PrPSc peak was observed in the middle part of the gradient. This population approximately corresponds to multimers of 12–30 PrP molecules, if constituted of PrP only. For two strains, infectivity peaked in a markedly different region of the gradient. This most infectious component sedimented very slowly, suggesting small size oligomers and/or low density PrPSc aggregates. Extending this study to hamster prions passaged in hamster PrP transgenic mice revealed that the highly infectious, slowly sedimenting particles could be a feature of strains able to induce a rapidly lethal disease. Our findings suggest that prion infectious particles are subjected to marked strain-dependent variations, which in turn could influence the strain biological phenotype, in particular the replication dynamics. 相似文献
11.
Victoria A. Lawson Brooke Lumicisi Jeremy Welton Dorothy Machalek Katrina Gouramanis Helen M. Klemm James D. Stewart Colin L. Masters David E. Hoke Steven J. Collins Andrew F. Hill 《PloS one》2010,5(8)
Background
The accumulation of protease resistant conformers of the prion protein (PrPres) is a key pathological feature of prion diseases. Polyanions, including RNA and glycosaminoglycans have been identified as factors that contribute to the propagation, transmission and pathogenesis of prion disease. Recent studies have suggested that the contribution of these cofactors to prion propagation may be species specific.Methodology/Principal Finding
In this study a cell-free assay was used to investigate the molecular basis of polyanion stimulated PrPres formation using brain tissue or cell line derived murine PrP. Enzymatic depletion of endogenous nucleic acids or heparan sulphate (HS) from the PrPC substrate was found to specifically prevent PrPres formation seeded by mouse derived PrPSc. Modification of the negative charge afforded by the sulphation of glycosaminoglycans increased the ability of a familial PrP mutant to act as a substrate for PrPres formation, while having no effect on PrPres formed by wildtype PrP. This difference may be due to the observed differences in the binding of wild type and mutant PrP for glycosaminoglycans.Conclusions/Significance
Cofactor requirements for PrPres formation are host species and prion strain specific and affected by disease associated mutations of the prion protein. This may explain both species and strain dependent propagation characteristics and provide insights into the underlying mechanisms of familial prion disease. It further highlights the challenge of designing effective therapeutics against a disease which effects a range of mammalian species, caused by range of aetiologies and prion strains. 相似文献12.
Kentaro Masujin Yujing Shu Yoshio Yamakawa Ken'ichi Hagiwara Tetsutaro Sata Yuichi Matsuura Yoshifumi Iwamaru Morikazu Imamura Hiroyuki Okada Shirou Mohri Takashi Yokoyama 《朊病毒》2008,2(3):123-128
A case of L-type-like atypical bovine spongiform encephalopathy was detected in 14-year-old Japanese black beef cattle (BSE/JP24). To clarify the biological and biochemical properties of the prion in BSE/JP24, we performed a transmission study with wild-type mice and bovinized transgenic mice (TgBoPrP). The BSE/JP24 prion was transmitted to TgBoPrP mice with the incubation period of 199.7 ± 3.4 days, which was shorter than that of classical BSE (C-BSE) (223.5 ± 13.5 days). Further, C-BSE was transmitted to wild-type mice with the incubation period of about 409 days, whereas BSE/JP24 prion inoculated mice showed no clinical signs up to 649 days. Severe vacuolation and a widespread and uniform distribution of PrPSc were pathologically observed in the brain of BSE/JP24 prion affected TgBoPrP mice. The molecular weight and glycoform ratio of PrPSc in BSE/JP24 were different from those in C-BSE, and PrPSc in BSE/JP24 exhibited weaker proteinase K resistance than that in C-BSE. These findings revealed that the BSE/JP24 prion has distinct biological and biochemical properties reported for that of C-BSE. Interestingly, a shorter incubation period was observed at the subsequent passage of the BSE/JP24 prion to TgBoPrP mice (152.2 ± 3.1 days). This result implies that BSE/JP24 prion has newly emerged and showed the possibility that L-type BSE prion might be classified into multiple strains.Key words: prion, atypical BSE, PrPSc 相似文献
13.
14.
《朊病毒》2013,7(4):275-282
Prion diseases range from being highly infectious, for example scrapie and CWD which show facile transmission between susceptible individuals, to showing negligible horizontal transmission, such as BSE and CJD which are spread via food or iatrogenically respectively. Scrapie and CWD display considerable in vivo dissemination, with PrPSc and infectivity being found in a range of peripheral tissues. This in vivo dissemination appears to facilitate the recently reported excretion of prion through multiple routes such as from skin, faeces, urine, milk, nasal secretions, saliva and placenta. Furthermore, excreted scrapie and CWD agent is detected within environmental samples such as water and on the surfaces of inanimate objects. The cycle of ‘uptake of prion from the environment - widespread in vivo prion dissemination - prion excretion - prion persistence in the environment’ is likely to explain the facile transmission and maintenance of these diseases within wild and farmed populations over many years. 相似文献
15.
Noriyuki Nishida Shigeru Katamine Kazuto Shigematsu Akira Nakatani Nobuhiro Sakamoto Sumitaka Hasegawa Ryota Nakaoke Ryuichiro Atarashi Yasufumi Kataoka Tsutomu Miyamoto 《Cellular and molecular neurobiology》1997,17(5):537-545
1. The cellular prion protein, designated PrPc, is a key molecule in the prion diseases but its physiological function remains unknown. To elucidate whether PrPc plays some role in the central nervous system, we established a line of mice in which the PrP gene had been disrupted and subsequently conducted long-term observations.2. Performance in latent learning and passive avoidance was evaluated using water-finding and step-through tests, respectively.3. PrP
–/– mice showed impaired performance in the water-finding test, indicating a disturbance in latent learning, at 23 weeks of age. In the step-through test, although the PrP
–/– mice showed normal learning ability and short-term memory retention, they evidenced a significant disturbance in long-term memory retention.4. These results indicate that PrPc is needed for certain types of learning and memory and that the loss of function of this protein may contribute to the pathogenesis of prion diseases. 相似文献
16.
Two distinct forms of atypical bovine spongiform encephalopathies (H-BSE and L-BSE) can be distinguished from classical (C-) BSE found in cattle based on biochemical signatures of disease-associated prion protein (PrPSc). H-BSE is transmissible to wild-type mice—with infected mice showing a long survival period that is close to their normal lifespan—but not to hamsters. Therefore, rodent-adapted H-BSE with a short survival period would be useful for analyzing H-BSE characteristics. In this study, we investigated the transmissibility of H-BSE to hamster prion protein transgenic (TgHaNSE) mice with long survival periods. Although none of the TgHaNSE mice manifested the disease during their lifespan, PrPSc accumulation was observed in some areas of the brain after the first passage. With subsequent passages, TgHaNSE mice developed the disease with a mean survival period of 220 days. The molecular characteristics of proteinase K-resistant PrPSc (PrPres) in the brain were identical to those observed in first-passage mice. The distribution of immunolabeled PrPSc in the brains of TgHaNSE mice differed between those infected with H-BSE as compared to C-BSE or L-BSE, and the molecular properties of PrPres in TgHaNSE mice infected with H-BSE differed from those of the original isolate. The strain-specific electromobility, glycoform profiles, and proteolytic cleavage sites of H-BSE in TgHaNSE mice were indistinguishable from those of C-BSE, in which the diglycosylated form was predominant. These findings indicate that strain-specific pathogenic characteristics and molecular features of PrPres in the brain are altered during cross-species transmission. Typical H-BSE features were restored after back passage from TgHaNSE to bovinized transgenic mice, indicating that the H-BSE strain was propagated in TgHaNSE mice. This could result from the overexpression of the hamster prion protein. 相似文献
17.
Kentaro Masujin Yuko Kaku-Ushiki Ritsuko Miwa Hiroyuki Okada Yoshihisa Shimizu Kazuo Kasai Yuichi Matsuura Takashi Yokoyama 《PloS one》2013,8(2)
The conformation of abnormal prion protein (PrPSc) differs from that of cellular prion protein (PrPC), but the precise characteristics of PrPSc remain to be elucidated. To clarify the properties of native PrPSc, we attempted to generate novel PrPSc-specific monoclonal antibodies (mAbs) by immunizing PrP-deficient mice with intact PrPSc purified from bovine spongiform encephalopathy (BSE)-affected mice. The generated mAbs 6A12 and 8D5 selectivity precipitated PrPSc from the brains of prion-affected mice, sheep, and cattle, but did not precipitate PrPC from the brains of healthy animals. In histopathological analysis, mAbs 6A12 and 8D5 strongly reacted with prion-affected mouse brains but not with unaffected mouse brains without antigen retrieval. Epitope analysis revealed that mAbs 8D5 and 6A12 recognized the PrP subregions between amino acids 31–39 and 41–47, respectively. This indicates that a PrPSc-specific epitope exists in the N-terminal region of PrPSc, and mAbs 6A12 and 8D5 are powerful tools with which to detect native and intact PrPSc. We found that the ratio of proteinase K (PK)-sensitive PrPSc to PK-resistant PrPSc was constant throughout the disease time course. 相似文献
18.
C. Maluquer de Motes S. Simon J. Grassi J.M. Torres M. Pumarola R. Girones 《Journal of applied microbiology》2008,105(5):1649-1657
Aims: This paper describes a procedure for evaluating the presence and the stability of the proteinase K-resistant form of the prion protein (PrPres) in slaughterhouse wastewater. Methods and Results: Wastewater samples were spiked with either scrapie or bovine spongiform encephalopathy agents and PrPres was concentrated and detected by western blotting. The detection limit was estimated to be 2–4 μg of either scrapie or BSE-infected brain tissue in 15 ml of sewage. Wastewater samples from three abattoirs were analysed, two of which had processed BSE-infected animals. No PrPres was detected. The effect of sewage on the inoculum and the persistence of transmissible spongiform encephalopathy agents in wastewater were also considered. Conclusions: The results of the assay suggest that wastewaters from abattoirs where one positive BSE case has been identified would contain titres lower than 0·6–26 × 10−4 cattle oral ID50 per litre resulting from specified risk material tissue contamination. Moreover, the effect of abattoir wastewaters is to reduce the persistence of PrPres. Significance and Impact of the Study: The assay may be a useful tool for risk assessment studies and for reducing the potential risk of contamination with BSE via sewage sludge fertilizer procedures. 相似文献
19.
Baron T Bencsik A Vulin J Biacabe AG Morignat E Verchere J Betemps D 《PLoS pathogens》2008,4(8):e1000137
The protease-resistant prion protein (PrP(res)) of a few natural scrapie isolates identified in sheep, reminiscent of the experimental isolate CH1641 derived from a British natural scrapie case, showed partial molecular similarities to ovine bovine spongiform encephalopathy (BSE). Recent discovery of an atypical form of BSE in cattle, L-type BSE or BASE, suggests that also this form of BSE might have been transmitted to sheep. We studied by Western blot the molecular features of PrP(res) in four "CH1641-like" natural scrapie isolates after transmission in an ovine transgenic model (TgOvPrP4), to see if "CH1641-like" isolates might be linked to L-type BSE. We found less diglycosylated PrP(res) than in classical BSE, but similar glycoform proportions and apparent molecular masses of the usual PrP(res) form (PrP(res) #1) to L-type BSE. However, the "CH1641-like" isolates differed from both L-type and classical BSE by an abundant, C-terminally cleaved PrP(res) product (PrP(res) #2) specifically recognised by a C-terminal antibody (SAF84). Differential immunoprecipitation of PrP(res) #1 and PrP(res) #2 resulted in enrichment in PrP(res) #2, and demonstrated the presence of mono- and diglycosylated PrP(res) products. PrP(res) #2 could not be obtained from several experimental scrapie sources (SSBP1, 79A, Chandler, C506M3) in TgOvPrP4 mice, but was identified in the 87V scrapie strain and, in lower and variable proportions, in 5 of 5 natural scrapie isolates with different molecular features to CH1641. PrP(res) #2 identification provides an additional method for the molecular discrimination of prion strains, and demonstrates differences between "CH1641-like" ovine scrapie and bovine L-type BSE transmitted in an ovine transgenic mouse model. 相似文献
20.
Feline spongiform encephalopathy (FSE) is considered to be related to bovine spongiform encephalopathy (BSE) and has been reported in domestic cats as well as in captive wild cats including cheetahs, first in the United Kingdom (UK) and then in other European countries. In France, several cases were described in cheetahs either imported from UK or born in France. Here we report details of two other FSE cases in captive cheetah including a 2nd case of FSE in a cheetah born in France, most likely due to maternal transmission. Complete prion protein immunohistochemical study on both brains and peripheral organs showed the close likeness between the two cases. In addition, transmission studies to the TgOvPrP4 mouse line were also performed, for comparison with the transmission of cattle BSE. The TgOvPrP4 mouse brains infected with cattle BSE and cheetah FSE revealed similar vacuolar lesion profiles, PrPd brain mapping with occurrence of typical florid plaques. Collectively, these data indicate that they harbor the same strain of agent as the cattle BSE agent. This new observation may have some impact on our knowledge of vertical transmission of BSE agent-linked TSEs such as in housecat FSE, or vCJD. 相似文献