Sunday, November 23, 2014

Transmission Characteristics of Variably Protease-Sensitive Prionopathy

Transmission Characteristics of Variably Protease-Sensitive Prionopathy


Silvio Notari,1 Xiangzhu Xiao,1 Juan Carlos Espinosa, Yvonne Cohen, Liuting Qing, Patricia Aguilar-Calvo, Diane Kofskey, Ignazio Cali, Laura Cracco, Qingzhong Kong, Juan Maria Torres, Wenquan Zou, and Pierluigi Gambetti


Variably protease-sensitive prionopathy (VPSPr), a recently identified and seemingly sporadic human prion disease, is distinct from Creutzfeldt-Jakob disease (CJD) but shares features of Gerstmann-Sträussler-Scheinker disease (GSS). However, contrary to exclusively inherited GSS, no prion protein (PrP) gene variations have been detected in VPSPr, suggesting that VPSPr might be the long-sought sporadic form of GSS. The VPSPr atypical features raised the issue of transmissibility, a prototypical property of prion diseases. We inoculated VPSPr brain homogenate into transgenic mice expressing various levels of human PrP (PrPC). On first passage, 54% of challenged mice showed histopathologic lesions, and 34% harbored abnormal PrP similar to that of VPSPr. Surprisingly, no prion disease was detected on second passage. We concluded that VPSPr is transmissible; thus, it is an authentic prion disease. However, we speculate that normal human PrPC is not an efficient conversion substrate (or mouse brain not a favorable environment) and therefore cannot sustain replication beyond the first passage.


Prion diseases include a variety of animal and human conditions that might be sporadic, inherited, or acquired by infection. Despite this diversity, most prion diseases are thought to share the same pathogenetic mechanism whereby the cellular prion protein (PrPC) is templated into an abnormal and pathogenic conformer, commonly identified as scrapie PrP (PrPSc) (1). Therefore, conversion by templating is the basic mechanism that causes disease and sustains disease transmission among humans (2). However, data have shown that propagation, disease manifestation, and transmissibility might occur separately in various ways (3,4).


The phenotype of human prion diseases is highly heterogeneous. This characteristic is largely due to the variable genotype at codon 129, the site of a methionine/ valine (MV) polymorphism in the human PrP gene, and the molecular characteristics of the associated PrPSc (5). A further major distinction that has been applied to human prion diseases for years is based on the experimental transmissibility of these diseases to hosts thought to be permissive for exogenous human PrPSc (6). Based on this principle, the sporadic form of Creutzfeldt-Jakob disease (sCJD) belongs to the transmissible disease group, whereas most of the Gerstmann-Sträussler-Scheinker diseases (GSS), a group comprising exclusively inherited forms, were considered difficult to transmit or not transmissible (7–10). However, an increasing number of findings have challenged this distinction. Replication of infectious PrPSc occurs in the absence of clinical signs in the host, or even in the absence of detectable disease, by histologic and Western blot (WB) examinations. Yet, infectivity can be demonstrated in subsequent passages to more susceptible hosts (9,11,12). Finally, disease transmissibility has recently been demonstrated for a subtype of GSS previously thought to be nontransmissible (8,10,13).


In 2008 and 2010, we introduced a novel human prion disease, presumably sporadic, that we named variably protease-sensitive prionopathy (VPSPr) (14–16). VPSPr differs from sCJD in several aspects. The clinical presentation and the frequent slow progression evoke the features of atypical dementias, such as frontotemporal dementia, diffuse Lewy body disease, or normal pressure hydrocephalus (17). The flocculent PrP immunostaining pattern, which includes the frequent presence of PrP peculiar amyloid plaques, differs from those of other sporadic prion diseases. However, the most distinctive VPSPr feature rests on the characteristics of the associated PrPSc, especially the electrophoretic profile and resistance to the commonly used protease, such as proteinase K (PK) (14,15,17). VPSPr-associated, PK-resistant PrPSc (resPrPSc) forms a distinctive 5-band electrophoretic profile, comprising various fragments truncated at the N terminal and at least 1 fragment truncated at both N and C terminals, which consequently lacks the GPI (glycosylphosphatidylinositol) anchor (14). Furthermore, the N-truncated fragments do not include the diglycosylated PrPSc isoforms but only 1 of 2 monoglycosylated and the unglycosylated isoforms (18), and upon cleavage of the glycans, these fragments form 3 PK-resistant WB bands in VPSPr preparations. In contrast, the electrophoretic profile of sCJD resPrPSc is characterized by 3 bands, including diglycosylated, 2 monoglycosylated, and unglycosylated isoform, all of which harbor the GPI anchor and form only 1 band after glycan removal (19). However, VPSPr also occasionally displays small amounts of typical 3 electrophoretic band–forming resPrPSc on WB of basal ganglia and other deep cerebral structures (14). On the whole, the VPSPr 5-band ladder profile is more akin to the electrophoretic profile of PrPSc in most GSS subtypes, although contrary to GSS, no mutation in the PrP gene open reading frame has been observed in VPSPr (14–16). Given this similarity, Zou et al. hypothesized that VPSPr is the sporadic form of GSS (15). Like sCJD, VPSPr affects persons harboring each of 3 PrPC 129 genotypes: methionine and valine homozygosity (MM, VV) and MV heterozygosity. The 3 genotypic subtypes of VPSPr differ slightly in clinical presentation, duration, histopathologic features, and PK resistance of the PrPSc (15).


The similarity in the PrPSc electrophoretic profiles with GSS, which was regarded as not transmissible, called into question the transmissibility of VPSPr and prompted use of the term prionopathy rather than prion disease. The present study addresses this issue. Transgenic (Tg) mice expressing various levels of human PrPC harboring methionine (M) or valine (V) at position 129 underwent intracranial inoculation with brain homogenates (BH) from several human case-patients with VPSPr associated with each of the three 129 genotypes (15). Surprisingly, VPSPr was transmitted as an asymptomatic disease characterized by focal accumulation of VPSPr-like PrPSc in the first passage, but no prion disease could be demonstrated in the second passage.






The experiments reported here, which probed transmissibility of VPSPr to Tg mice expressing human PrPC, yielded puzzling results. On first passage, all hosts remained asymptomatic, but 54% showed focal deposition of PrPSc in the form of prion plaques by immunohistochemical analysis. In 34% of animals, small amounts of resPrPSc were demonstrated by WB (Figures 1, 3). The PrPSc recovered from affected mice recapitulated the electrophoretic profile and immunoreactivity features of the VPSPr-129VV PrPSc, even after removal of the sugar moiety. However, mouse PrPSc was apparently more PK-resistant than the PrPSc from VPSPr-129VV case-patients (Figure 3) (15). In contrast, on second passage, all Tg mice were negative at clinical and histopathologic examinations and harbored no PrPSc that could be definitely identified by WB, even up to 800 dpi.


These findings pose several challenging questions. The first question concerns whether the PrPSc recovered on first passage represents the residual inoculum rather than de novo PrPSc generated by conversion of the host’s PrPC. We believe this possibility is made unlikely by our experiment showing that the PrPSc in the VPSPr inoculum was no longer detectable by immunohistochemical and WB analyses in Tg(HuPrP-129VV) mice 35 dpi.


Furthermore, histopathologic changes and PrPSc detection, indicating VPSPr transmission, were observed only when the host and the inoculum were syngenic at PrP codon 129. This genotypic selectivity is not compatible with the notion that the PrPSc detected in the hosts was from the residual inoculum. Finally, several other studies have shown that PrPSc associated with the inoculum is rapidly cleared (12,26–30). These observations support the conclusion that histopathologic changes and the PrPSc recovered in the positive VPSPrchallenged mice result from de novo mouse PrPSc generated by templated conversion, although at a very low level. The lack of clinical signs in the affected mice can be easily explained by the characteristics and localization of the plaques and of the spongiform degeneration, both of which affected limited regions depopulated of neuronal cells and processes.


Prion plaques similar in type and topography to those we observed have been reported alone or associated with spongiform degeneration in mice challenged with prions of various origins (9,11,29–32). In 3 studies, plaque deposits seem to be especially similar to those observed by us. In the first, the plaques were detected on the second passage of vCJD in Tg mice expressing human PrPC-129V (Tg152) (11,29). The second and third studies used Tg mice expressing mouse PrP harboring the P101L variation (101LL mice), which is the equivalent of the P102L human mutation linked to a GSS subtype (9,30). In the last 2 experiments, Tg101LL mice were challenged with “atypical” P102L GSS (i.e., GSS associated only with 7-kDa PrPSc PK-resistant fragment rather than with the “typical” P102L GSS that is also associated with the classical 3-band resPrPSc) or with BH from TgGSS-22, a Tg mouse model of GSS in which prion disease spontaneously develops (9,30). All affected mice of these 3 studies remained asymptomatic like those of our study, further supporting the notion that focal prion plaque deposition in periventricular regions is not sufficient to produce major clinical signs. Despite the common histopathologic features, these mice were associated with electrophoretically distinct PrPSc species.


In the experiment of vCJD transmission, PrPSc harvested from challenged Tg152 mice showed the classical 3 PKresistant bands as in vCJD, but they displayed a higher molecular mass than in vCJD (11). Minimal quantity of resPrPSc recovered at ≈30 kDa was detected only in 1 of 5 plaque-harboring 101LL mice challenged with atypical P102L GSS (9), whereas 101LL mice inoculated with TgGSS-22 BH showed no detectable PrPSc by WB (30). Although to some extent the variability of the PrPSc electrophoretic profiles between the experiments with Tg101LL and our experiments might be due to variations in WB methods, the PrPSc diversity in these 3 studies and in our study suggests that focal plaque formation at the border between the hippocampus and corpus callosum is not strictly PrPSc strain specific. However, this brief review indicates that peri-hippocampal plaque deposition is preferentially detected in hosts challenged with PrPSc species that form plaques in the natural disease, such as vCJD, GSS, and VPSPr.


The lack of histologic lesions and PrPSc on second passage in both Tg(HuPrP129V) and Tg(HuPrP129M) mice challenged with BH from the most severely affected first-passage mice is unusual. However, comparable findings have been reported in at least 2 previous studies. In the first, 101LL mice challenged with affected TgGSS-22 BH (a Tg mouse in which a GSS-like disease spontaneously develops) harbored fewer plaques on second passage than on first, suggesting decreased replication of the seed on second passage (9,30). In the second study, first passage of BH from cattle affected by bovine spongiform encephalopathy to Tg152 mice (expressing human PrPC- 129V) resulted in clinical disease associated with diffuse brain deposition of PrP as demonstrated by immunostaining (11), even though no resPrPSc could be demonstrated by WB. On second passage in the same Tg152 mice, no evidence of prion disease could be demonstrated either by PrP immunostaining or WB, as in our study (11). However, BH from these negative Tg152 produced a full prion disease after inoculation into wild-type FVB mice. This remarkable finding indicates that prion transmissibility (or infectivity) can be sustained in hosts with no demonstrable prion diseases (according to commonly used methods), and that it can be rescued through passage to an appropriate host (11).


Interpreting our findings also in the light of the above data, we propose that normal human PrPC is not a suitable substrate (or mouse brain is not a favorable environment) to sustain conversion to VPSPr PrPSc. Thus, long incubations are required to induce modest and asymptomatic PrPSc deposition. Nevertheless, the PrPSc generated in the host on first passage seems to match the conformation of the PrPSc from the inoculum, based on the finding that PK-resistant PrPSc fragments of similar size are recovered from host and donor preparations. This also indicates that little or no PrPSc adaptation has occurred during the first passage (32). The apparent failure of the second passage to transmit detectable disease might be due to the inadequate amplification of VPSPr PrPSc during primary transmission, which would result in a second passage PrPSc inoculum more diluted than the VPSPr brain extract used in the primary transmission. This line of reasoning raises the possibility that if VPSPr PrPSc were exposed to a favorable PrP substrate (or brain environment), it might replicate efficiently. This conjecture is reinforced by 2 recent findings. First, preliminary findings show that VPSPr can be transmitted to bank voles more easily than to the Tg(HuPrP) used in the present experiments (33). Second, transmissibility of GSS linked to the A117V mutation has been recently demonstrated (10). GSS-A117V is commonly viewed as a “classic” GSS subtype, given the distinct features of its phenotype that is characterized by prominent prion plaques with limited spongiform degeneration and a PrPSc WB profile dominated by a highly PK-resistant fragment of 7–8 kDa (34). Early failures to transmit GSS-A117V and the evidence that the presence of the A117V mutation altered the topology of PrP led to the conclusions that 1) GSS-A117V was not transmissible and 2) its underlying pathogenetic mechanism was not based on a PrPC-to-PrPSc conversion process (8).


After inoculation with BH from GSS-A117V–affected patients, Tg mice expressing human PrP, harboring the A117V mutation, developed a prion disease associated with a histologic phenotype and PrPSc that roughly recapitulated those of the human disease. However, only one fourth of the inoculated mice were symptomatic with incubation periods >600 days, whereas more than half harbored plaques, PrPSc, or both (10). No second passage was reported. This study shows that an allegedly nontransmissible prion disease can be transmitted (at least at first passage) if a suitable host is selected.


In conclusion, we propose that VPSPr is transmissible and, therefore, is an authentic prion disease. However, transmissibility cannot be sustained through serial passages presumably because human PrPC (or the mouse brain environment) cannot efficiently convert and propagate the VPSPr PrPSc species. If this is the case, uncovering the properties of human PrP that are required to replicate more efficiently the prion strains associated with VPSPr may help clarify the PrPSc mode of formation in this intriguing disease.



>>> We concluded that VPSPr is transmissible; thus, it is an authentic prion disease.


Variably Protease-Sensitive Prionopathy, a Unique Prion Variant with Inefficient Transmission


Properties Abigail B. Diack,1 Diane L. Ritchie,1 Alexander H. Peden, Deborah Brown, Aileen Boyle, Laura Morabito, David Maclennan, Paul Burgoyne, Casper Jansen, Richard S. Knight, Pedro Piccardo, James W. Ironside,1 and Jean C. Manson1


Variably protease-sensitive prionopathy (VPSPr) can occur in persons of all codon 129 genotypes in the human prion protein gene (PRNP) and is characterized by a unique biochemical profile when compared with other human prion diseases. We investigated transmission properties of VPSPr by inoculating transgenic mice expressing human PRNP with brain tissue from 2 persons with the valine-homozygous (VV) and 1 with the heterozygous methionine/valine codon 129 genotype. No clinical signs or vacuolar pathology were observed in any inoculated mice. Small deposits of prion protein accumulated in the brains of inoculated mice after challenge with brain material from VV VPSPr patients. Some of these deposits resembled microplaques that occur in the brains of VPSPr patients. Comparison of these transmission properties with those of sporadic Creutzfeldt-Jakob disease in the same lines of mice indicated that VPSPr has distinct biological properties. Moreover, we established that VPSPr has limited potential for human-to-human transmission.






The inoculation of homogenates prepared from the brains of 3 patients with VPSPr (UK-MV, UK-VV and NL-VV) into transgenic mice expressing the different forms of the human PrP gene has resulted in very

different transmission properties when compared with those of previously characterized sCJD strains (3). No clinical disease or vacuolar pathology was observed in any of the mice. The only evidence for transmission of disease was the neuropathologic finding of abnormal PrP accumulation in the form of microplaque-like and granular deposits in the hippocampus and subventricular areas of the brain. These results contrast considerably with those observed with sCJD in the same HuMM/HuMV/ HuVV mouse lines (3). Sporadic CJD transmits to all these mouse lines, as indicated by evidence of clinical signs and vacuolar pathology and/or PrP deposition, and the combination of these transmission properties has resulted in the identification of 4 strains of sCJD (3). Of the 4 sCJD strains, subtype VV2 showed the greatest frequency of clinical (13/16), vacuolar (16/16), and pathologic (15/15) signs of prion disease following inoculation into HuVV mice (Table 3) (3). In contrast, the MM2 subtype of sCJD showed the least transmission to the mice: no mice had clinical signs or vacuolar pathology, and only 3 of 17 HuVV and 2 of 18 HuMV mice had evidence of PrP deposition in the form of small punctate deposits in the thalamus (Table 3) (3). Although this transmission of the MM2 subtype might be considered similar to that of VPSPr, the PrP deposition differed in form and brain area compared with the deposition observed in the VPSPr studies. Unlike sCJD, which shows transmission from patients with all 3 codon 129 genotypes, only VPSPr from the 2 patients with codon 129VV provided evidence of transmission.


This low rate of transmission may be due to low levels of PrPres in the brain homogenates that were inoculated, or it could be that the PrP genotype plays a role in transmission of disease.


Prion disease propagation involves the aggregation of abnormal PrP that acts as a template for further aggregation within the brain, a process termed seeding (21,22). The spread of PrP within the brain appears to occur in cell-to-cell fashion in well-defined neuroanatomic pathways (23), the mechanisms of which are yet to be elucidated despite extensive studies. Prion diseases have the potential to be transmissible between persons, a fact that raises public health concerns, particularly regarding vCJD. Assessing the risk for transmission is a challenge because of the varied nature of prion diseases and conflicting evidence over the mechanisms of transmission. Risk assessment is made even more complicated by the existence of prion disease models in which negligible amounts of PrPres are associated with high infectivity titers in vivo (24) and also of models in which PrPres in the form of amyloid plaques develops in the absence of clinical disease or spongiform changes (25).


It could be argued that the observation of small plaque-like amyloid deposits in the brains of mice with no neurologic signs of disease after the inoculation of brain homogenates prepared from patients with VPSPr does not indicate disease transmission. Instead, the deposits could indicate an amyloid seeding phenomenon akin to that observed following the experimental inoculation of primates with brain tissue from patients with Alzheimer disease (26). In those experiments, amyloid β seeding occurred in the primate brain in the absence of any clinical signs. Precedence of this phenomenon in prion disease has been set by Piccardo et al. (27), who showed similar results in a mouse model system of prion disease transmission. However, in our study, the brain of 1 mouse exhibited intensely stained, small, round granules within the hippocampus in addition to the plaque-like deposits (Figure 4). These small granules are reminiscent of the microplaques found in brain tissue of humans with VPSPr (4,5). Furthermore, with 4 PrP antibodies, the microplaque deposits in the mouse brain showed the same pattern of differential immunoreactivity as that in the brain of patients with VPSPr (5,6,17). Moreover astrocytosis in the vicinity of the microplaques was also observed in this mouse (Figure 5). This type of astrocytic response is observed in all our model systems of transmissible prion disease, but is absent from the nontransmissible forms of PrP (i.e., amyloid plaques in absence of clinical disease), suggesting that this single mouse may represent a transmission of infection rather than a consequence of seeding of inoculum (25,28). Second passage in the same mouse line will be required to prove this interpretation, but such a study will take an additional 3 years to complete. Although understanding the mechanisms of transmission is an interesting facet of this study, our primary finding is that VPSPr is capable of transmission to transgenic mice expressing PrP, albeit at extremely low levels compared with those of other transmissible prion diseases (e.g., sCJD and vCJD). We demonstrate that VPSPr is a disease with biological properties distinct from those of sCJD and with a limited, but not negligible, potential for infectivity. These results demonstrate the importance of continuing surveillance to fully uncover the growing spectrum of human prion diseases.



>>> We demonstrate that VPSPr is a disease with biological properties distinct from those of sCJD and with a limited, but not negligible, potential for infectivity. These results demonstrate the importance of continuing surveillance to fully uncover the growing spectrum of human prion diseases.


Friday, January 10, 2014


vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???



Monday, November 3, 2014


*** The prion protein protease sensitivity, stability and seeding activity in variably protease sensitive prionopathy brain tissue suggests molecular overlaps with sporadic Creutzfeldt-Jakob disease







*** The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.




OR-10: Variably protease-sensitive prionopathy is transmissible in bank voles


Romolo Nonno,1 Michele Di Bari,1 Laura Pirisinu,1 Claudia D’Agostino,1 Stefano Marcon,1 Geraldina Riccardi,1 Gabriele Vaccari,1 Piero Parchi,2 Wenquan Zou,3 Pierluigi Gambetti,3 Umberto Agrimi1 1Istituto Superiore di Sanità; Rome, Italy; 2Dipartimento di Scienze Neurologiche, Università di Bologna; Bologna, Italy; 3Case Western Reserve University; Cleveland, OH USA


Background. Variably protease-sensitive prionopathy (VPSPr) is a recently described “sporadic”neurodegenerative disease involving prion protein aggregation, which has clinical similarities with non-Alzheimer dementias, such as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is the electrophoretic pattern of PrPSc after digestion with proteinase K (PK). After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern similar to that described in GSS cases. The clinical and pathological features of VPSPr raised the question of the correct classification of VPSPr among prion diseases or other forms of neurodegenerative disorders. Here we report preliminary data on the transmissibility and pathological features of VPSPr cases in bank voles.


Materials and Methods. Seven VPSPr cases were inoculated in two genetic lines of bank voles, carrying either methionine or isoleucine at codon 109 of the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical diagnosis in voles was confirmed by brain pathological assessment and western blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.


Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission in BvM109. Overall, 3 voles were positive with survival time between 290 and 588 d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form of the typical PrP27–30, which was indistinguishable to that previously observed in BvM109 inoculated with sCJDMM1 cases.


In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until now. Overall, 5 voles were positive with survival time between 281 and 596 d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like PrPSc electrophoretic pattern, characterized by low molecular weight PrPres. These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus and the N-terminus. Second passages are in progress from these first successful transmissions.


Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109.


The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.



Monday, August 9, 2010


Variably protease-sensitive prionopathy: A new sporadic disease of the prion protein or just more Prionbaloney ?



Wednesday, March 28, 2012







Monday, February 24, 2014


Sporadic Fatal Insomnia in an Adolescent



To the best of our knowledge, this is the first case of CJD combined with Lewy body disease and argirophilic grain disease. Furthermore, we believe this case is an extremely rare combination of MM2-cortical-type and MM2-thalamic-type sporadic CJD (sCJD), which explains the broad spectrum of MM2-type sCJD findings and symptoms. Moreover, histological features of possible Alzheimer's disease were also reported.



Wednesday, September 03, 2014


Coexistence of mixed phenotype Creutzfeldt-Jakob disease, Lewy body disease and argyrophilic grain disease plus histological features of possible Alzheimer's disease: A multi-protein disorder in an autopsy case



Sunday, August 09, 2009


CJD...Straight talk with...James Ironside...and...Terry Singeltary... 2009



Tuesday, August 18, 2009


BSE-The Untold Story - joe gibbs and singeltary 1999 – 2009



Monday, October 10, 2011


EFSA Journal 2011 The European Response to BSE: A Success Story




EFSA and the European Centre for Disease Prevention and Control (ECDC) recently delivered a scientific opinion on any possible epidemiological or molecular association between TSEs in animals and humans (EFSA Panel on Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical BSE prions as the only TSE agents demonstrated to be zoonotic so far but the possibility that a small proportion of human cases so far classified as "sporadic" CJD are of zoonotic origin could not be excluded. Moreover, transmission experiments to non-human primates suggest that some TSE agents in addition to Classical BSE prions in cattle (namely L-type Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME) and chronic wasting disease (CWD) agents) might have zoonotic potential.






see follow-up here about North America BSE Mad Cow TSE prion risk factors, and the ever emerging strains of Transmissible Spongiform Encephalopathy in many species here in the USA, including humans ;



Thursday, August 12, 2010


Seven main threats for the future linked to prions


First threat


The TSE road map defining the evolution of European policy for protection against prion diseases is based on a certain numbers of hypotheses some of which may turn out to be erroneous. In particular, a form of BSE (called atypical Bovine Spongiform Encephalopathy), recently identified by systematic testing in aged cattle without clinical signs, may be the origin of classical BSE and thus potentially constitute a reservoir, which may be impossible to eradicate if a sporadic origin is confirmed.


***Also, a link is suspected between atypical BSE and some apparently sporadic cases of Creutzfeldt-Jakob disease in humans. These atypical BSE cases constitute an unforeseen first threat that could sharply modify the European approach to prion diseases.


Second threat





Saturday, June 25, 2011


Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque


"BSE-L in North America may have existed for decades"



Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.




The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...



Thursday, March 29, 2012


atypical Nor-98 Scrapie has spread from coast to coast in the USA 2012


NIAA Annual Conference April 11-14, 2011San Antonio, Texas





Aspects of the Cerebellar Neuropathology in Nor98


Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,


Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.


***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.







R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (; 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway


Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.


*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.





A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes


Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations


*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway


***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)


Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. *** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.



Monday, December 1, 2008


When Atypical Scrapie cross species barriers




Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.




Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.


The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.


Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.


Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.


(i) the unsuspected potential abilities of atypical scrapie to cross species barriers


(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier


These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.



Friday, February 11, 2011


Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues



Monday, December 14, 2009


Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types


(hmmm, this is getting interesting now...TSS)


Sporadic CJD type 1 and atypical/ Nor98 scrapie are characterized by fine (reticular) deposits,


see also ;


All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.



Saturday, July 6, 2013


Small Ruminant Nor98 Prions Share Biochemical Features with Human Gerstmann-Sträussler-Scheinker Disease and Variably Protease-Sensitive Prionopathy


Research Article



Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014


Transmissible Spongiform Encephalopathy TSE Prion Disease have now been discovered in a wide verity of species across North America. typical C-BSE, atypical L-type BASE BSE, atypical H-type BSE, atypical H-G BSE, of the bovine, typical and atypical Scrapie strains, in sheep and goats, with atypical Nor-98 Scrapie spreading coast to coast in about 5 years. Chronic Wasting Disease CWD in cervid is slowly spreading without any stopping it in Canada and the USA and now has mutated into many different strains. Transmissible Mink Encephalopathy TME outbreaks. These Transmissible Spongiform Encephalopathy TSE Prion Disease have been silently mutating and spreading in different species in North America for decades.


The USDA, FDA, et al have assured us of a robust Triple BSE TSE prion Firewall, of which we now know without a doubt, that it was nothing but ink on paper. Since the 1997 mad cow feed ban in the USA, literally tons and tons of banned mad cow feed has been put out into commerce, never to return, as late as December of 2013, serious, serious breaches in the FDA mad cow feed ban have been documented. The 2004 enhanced BSE surveillance program was so flawed, that one of the top TSE prion Scientist for the CDC, Dr. Paul Brown stated ; Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.


see ;



The BSE surveillance and testing have also been proven to be flawed, and the GAO and OIG have both raised serious question as to just how flawed it has been (see GAO and OIG reports). North America has more documented TSE prion disease, in different documented species (excluding the Zoo BSE animals in the EU), then any other place on the Globe. This does not include the very likelihood that TSE prion disease in the domestic feline and canine have been exposed to high doses of the TSE prion disease vid pet food. To date, it’s still legal to include deer from cwd zone into pet food or deer food. Specified Risk Material i.e. SRM bans still being breach, as recently as just last month.


nvCJD or what they now call vCJD, another case documented in Texas last month, with very little information being released to the public on about this case? with still the same line of thought from federal officials, ‘it can’t happen here’, so another vCJD blamed on travel of a foreign animal disease from another country, while ignoring all the BSE TSE Prion risk factors we have here in the USA and Canada, and the time that this victim and others, do spend in the USA, and exposed to these risk factors, apparently do not count in any way with regard to risk factor. a flawed process of risk assessment.


sporadic CJD, along with new TSE prion disease in humans, of which the young are dying, of which long duration of illness from onset of symptoms to death have been documented, only to have a new name added to the pot of prion disease i.e. sporadic GSS, sporadic FFI, and or VPSPR. I only ponder how a familial type disease could be sporadic with no genetic link to any family member? when the USA is the only documented Country in the world to have documented two different cases of atypical H-type BSE, with one case being called atypical H-G BSE with the G meaning Genetic, with new science now showing that indeed atypical H-type BSE is very possible transmitted to cattle via oral transmission (Prion2014). sporadic CJD and VPSPR have been rising in Canada, USA, and the UK, with the same old excuse, better surveillance. You can only use that excuse for so many years, for so many decades, until one must conclude that CJD TSE prion cases are rising. a 48% incease in CJD in Canada is not just a blip or a reason of better surveillance, it is a mathematical rise in numbers. More and more we are seeing more humans exposed in various circumstance in the Hospital, Medical, Surgical arenas to the TSE Prion disease, and at the same time in North America, more and more humans are becoming exposed to the TSE prion disease via consumption of the TSE prion via deer and elk, cattle, sheep and goats, and for those that are exposed via or consumption, go on to further expose many others via the iatrogenic modes of transmission of the TSE prion disease i.e. friendly fire. I pondered this mode of transmission via the victims of sporadic FFI, sporadic GSS, could this be a iatrogenic event from someone sub-clinical with sFFI or sGSS ? what if?


Two decades have passed since Dr. Ironside first confirmed his first ten nvCJD victims in 1995. Ten years later, 2005, we had Dr. Gambetti and his first ten i.e. VPSPR in younger victims. now we know that indeed VPSPR is transmissible. yet all these TSE prion disease and victims in the USA and Canada are being pawned off as a spontaneous event, yet science has shown, the spontaneous theory has never been proven in any natural case of TSE prion disease, and scientist have warned, that they have now linked some sporadic CJD cases to atypical BSE, to atypical Scrapie, and to CWD, yet we don’t here about this in the public domain. We must make all human and animal TSE prion disease reportable in every age group, in ever state and internationally, we must have a serious re-evaluation and testing of the USA cattle herds, and we must ban interstate movement of all cervids. Any voluntary effort to do any of this will fail. Folks, we have let the industry run science far too long with regards to the TSE prion disease. While the industry and their lobbyist continues to funnel junk science to our decision policy makers, Rome burns. ...end




Sunday, June 29, 2014


Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014



Tuesday, August 12, 2014





Sunday, July 06, 2014


Dietary Risk Factors for Sporadic Creutzfeldt-Jakob Disease: A Confirmatory Case-Control Study


Conclusions—The a priori hypotheses were supported.


*Consumption of various meat products may be one method of transmission of the infectious agent for sCJD.



Monday, November 3, 2014




National Prion Disease Pathology Surveillance Center Cases Examined1 (October 7, 2014)


***6 Includes 11 cases in which the diagnosis is pending, and 19 inconclusive cases;


***7 Includes 12 (11 from 2014) cases with type determination pending in which the diagnosis of vCJD has been excluded.


***The sporadic cases include 2660 cases of sporadic Creutzfeldt-Jakob disease (sCJD),


***50 cases of Variably Protease-Sensitive Prionopathy (VPSPr)


***and 21 cases of sporadic Fatal Insomnia (sFI).



Sunday, November 23, 2014


*** Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas in June 2014 confirmed as USA case NOT European



Terry S. Singeltary Sr. on the Creutzfeldt-Jakob Disease Public Health Crisis *video*



Jeff Schwan, sporadic cjd, clustering, and BSE aka mad cow type disease, is there a link ? *video*



1997-11-10: Panorama - The british disease *video*



Sunday, September 6, 2009


MAD COW USA 1997 *video*



Tuesday, November 04, 2014


The pathological and molecular but not clinical phenotypes are maintained after second passage of experimental atypical bovine spongiform encephalopathy in cattle



*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply ;



Tuesday, August 12, 2014





Thursday, October 02, 2014


[Docket No. APHIS-2013-0064] Concurrence With OIE Risk Designations for Bovine Spongiform Encephalopathy



Saturday, August 14, 2010


BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY









Self-Propagative Replication of Ab Oligomers Suggests Potential Transmissibility in Alzheimer Disease


Received July 24, 2014; Accepted September 16, 2014; Published November 3, 2014



Singeltary comment ;





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