Tuesday, February 24, 2015

Human prion protein sequence elements impede cross-species chronic wasting disease transmission

Human prion protein sequence elements impede cross-species chronic wasting disease transmission

 

Timothy D. Kurt,1 Lin Jiang,2 Natalia Fernández-Borges,3 Cyrus Bett,1 Jun Liu,1 Tom Yang,1 Terry R. Spraker,4 Joaquín Castilla,3,5 David Eisenberg,2 Qingzhong Kong,6 and Christina J. Sigurdson1,7

 

1Departments of Pathology and Medicine, UCSD, La Jolla, California, USA. 2UCLA-DOE Institute, Howard Hughes Medical Institute, and Molecular Biology Institute, UCLA, Los Angeles, California, USA. 3CIC bioGUNE, Derio, Spain. 4Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA. 5IKERBASQUE, Basque Foundation for Science, Bilbao, Spain. 6Departments of Pathology and Neurology, and National Center for Regenerative Medicine, Case Western Reserve University, Cleveland, Ohio, USA. 7Department of Pathology, Microbiology, and Immunology, UCD, Davis, California, USA.

 

Chronic wasting disease (CWD) is a fatal prion disease of North American deer and elk and poses an unclear risk for transmission to humans. Human exposure to CWD occurs through hunting activities and consumption of venison from prioninfected animals. Although the amino acid residues of the prion protein (PrP) that prevent or permit human CWD infection are unknown, NMR-based structural studies suggest that the β2-α2 loop (residues 165–175) may impact species barriers. Here we sought to define PrP sequence determinants that affect CWD transmission to humans. We engineered transgenic mice that express human PrP with four amino acid substitutions that result in expression of PrP with a β2-α2 loop (residues 165–175) that exactly matches that of elk PrP. Compared with transgenic mice expressing unaltered human PrP, mice expressing the human-elk chimeric PrP were highly susceptible to elk and deer CWD prions but were concurrently less susceptible to human Creutzfeldt-Jakob disease prions. A systematic in vitro survey of amino acid differences between humans and cervids identified two additional residues that impacted CWD conversion of human PrP. This work identifies amino acids that constitute a substantial structural barrier for CWD transmission to humans and helps illuminate the molecular requirements for cross-species prion transmission.

 

Elucidating the determinants of cross-species prion transmission. Prions can transmit between different species; however, infection of a new species is typically characterized by prolonged, variable incubation periods and low attack rates (41, 42). Known determinants of interspecies prion conversion are (a) PrPC and PrPSc sequence similarity and (b) the conformation of the infectious prion (43, 44). Here we propose to add a third determinant, the presence of glutamines or asparagines in host PrPC within key interaction segments. These key segments will vary depending upon exposure in the PrPSc conformation. We found that human PrP with the E168Q and S170N substitutions was readily converted by CWD, whereas adding the N174T substitution, which increases homology with elk CWD but removes an asparagine, paradoxically led to a massive decrease in conversion. These results suggest that for CWD, the β2-α2 segment is accessible and interacts with host PrPC. These data also indicate that the presence of N/Qs in the loop can be a strong determinant for conversion that overrides certain sequence differences.

 

Glutamine- and asparagine-rich protein segments are proposed to play a role in protein aggregation due to side chain hydrogen bonding among amide groups that stabilizes adjacent β-strands (45–47). Asparagine residues are prevalent in the PrPC of bank voles, a species that is highly susceptible to CWD, sheep scrapie, and CJD, despite having many PrPC sequence mismatches with these infectious prions (48–51). Indeed, bank voles were recently designated the “universal acceptor for prions” (36). Similar to the bank vole, hamsters are susceptible to CWD and other prions (42, 52–54) and also have an N/Q-rich loop. Thus, it is possible that the bank vole–like sequence in the human β2-α2 loop creates a permissive host PrPC sequence that is converted by prions from other species, despite sequence mismatches. Consistent with the observation that N/Q residues lead to a lower species barrier, fewer N/Qs in key segments may be protective, as polymorphisms that replace a single N/Q residue — for example, Q168R in sheep PrPC (55, 56), Q219K in mouse PrPC (30), and Q219K in goat PrPC (57) (all human numbering) — correlate with profound resistance to certain prions in vivo.

 

Accumulating evidence suggests that the β2-α2 loop governs certain prion transmission barriers and conformational properties, reminiscent of Sup35 yeast prion segments, also shown to govern species barriers and strains (58). In transgenic mice, S170N and N174T loop substitutions increased susceptibility to CWD and hamster prions, led to resistance to sheep or cattle prions, and altered the RML mouse prion conformation (59). Here we show that replacing four human amino acids in the β2-α2 loop enabled infection with elk CWD and created a partial barrier for human CJD, as evidenced by the delayed infection kinetics. Additionally, HuPrPelk166–174-CJD showed a different glycosylation pattern as compared with human CJD prions, suggesting the emergence of a new CJD conformation. Surprisingly, passage of HuPrPelk166–174-CWD prions revealed efficient infection of all Tg(HuPrPelk166–174) mice, but not Tg(HuPrP) mice, despite only four amino acid differences in PrP.

 

snip...

 

In conclusion, we have identified the β2-α2 loop sequence of human PrPC as a major barrier to PrP conversion by CWD prions. The human-specific residues in the β2-α2 loop, particularly E168 and S170, appear to substantially raise the energetic barrier for conversion of human PrP by CWD prions, making conversion of sarhuman PrP highly unfavorable. Thus we propose the β2-α2 loop as a critical initial PrPC-PrPSc interaction site during the templating of human PrPC by either CWD or CJD prions. Although we cannot exclude the involvement of additional PrP segments that include 143 and 155, the β2-α2 loop may act as an important gatekeeper that promotes or impairs conversion, depending on the sequence (58). Since the loop substitutions in human PrP also markedly delayed infection with CJD, the β2-α2 loop segment may also be a key site for PrPC-CJD prion interaction and may indicate a potential therapeutic target for rationally designed stable peptides (63, 64) or inhibitors that block PrPC-PrPSc interaction and impede the progression of prion disease.

 

snip...

 

Discussion In 1996, ten cases of new variant CJD were reported in the UK with suspected links to the BSE epidemic (37, 38), and extensive evidence now supports that cattle BSE crossed the species barrier and infected humans (39, 40). With the realization that animal prions could transmit to humans, concerns arose that CWD in cervids may lead to cases of a novel form of CJD. Nevertheless, four laboratories have independently reported that transgenic mice expressing human PrP resist CWD infection, suggestive of a strong barrier to infection (9–12). Here we have identified the specific residues in human PrP that modulate CWD transmission. We report that CWD transmits to mice expressing a human-elk chimeric PrPC and show that the CWD-human species barrier is largely maintained by the humanspecific amino acids within the β2-α2 loop. Within the loop, human residues E168 and S170 are significant inhibitors of CWD conversion, as evidenced by in vitro conversion experiments. Human residues S143 and H155 likely also contribute to the CWD barrier. Collectively, these results help define the structural barriers that limit CWD transmission to humans.

 

 snip...

 

In conclusion, we have identified the β2-α2 loop sequence of human PrPC as a major barrier to PrP conversion by CWD prions. The human-specific residues in the β2-α2 loop, particularly E168 and S170, appear to substantially raise the energetic barrier for conversion of human PrP by CWD prions, making conversion of sarhuman PrP highly unfavorable. Thus we propose the β2-α2 loop as a critical initial PrPC-PrPSc interaction site during the templating of human PrPC by either CWD or CJD prions. Although we cannot exclude the involvement of additional PrP segments that include 143 and 155, the β2-α2 loop may act as an important gatekeeper that promotes or impairs conversion, depending on the sequence (58). Since the loop substitutions in human PrP also markedly delayed infection with CJD, the β2-α2 loop segment may also be a key site for PrPC-CJD prion interaction and may indicate a potential therapeutic target for rationally designed stable peptides (63, 64) or inhibitors that block PrPC-PrPSc interaction and impede the progression of prion disease.

 

snip...see full text ;

 


 

 

with TSE Prions, never say never...tss


every time some scientist claims an absolute about a TSE prion, it mutates, or science evolves further, and proves them wrong again.

 

like old typical scrapie would not, has not, transmitted to humans, when most science was saying otherwise, and now we have another study showing that indeed the potential for typical scrapie to transmit to man has been here all along. i am also, reminded of what one of the prion Gods said long ago about Scrapie and TSE prion, and also the myth that Scrapie genotypes ARR/ARQ and ARR/ARR are resistant.

 

Tuesday, December 16, 2014

 

Evidence for zoonotic potential of ovine scrapie prions

 

Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1, Affiliations Contributions Corresponding author Journal name: Nature Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821 Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014 Article tools Citation Reprints Rights & permissions Article metrics

 

Abstract

 

Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie prions remains unknown. Mice genetically engineered to overexpress the human ​prion protein (tgHu) have emerged as highly relevant models for gauging the capacity of prions to transmit to humans. These models can propagate human prions without any apparent transmission barrier and have been used used to confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie prions transmit to several tgHu mice models with an efficiency comparable to that of cattle BSE. The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans. These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.

 

Subject terms: Biological sciences• Medical research At a glance

 


 

why do we not want to do TSE transmission studies on chimpanzees $

 

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

 

snip...

 

R. BRADLEY

 


 

Suspect symptoms

 

What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?

 

28 Mar 01 Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.

 

Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.

 

"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris. Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb...

 

2001

 

Suspect symptoms

 

What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?

 

28 Mar 01

 

Like lambs to the slaughter

 

31 March 2001

 

by Debora MacKenzie Magazine issue 2284.

 

FOUR years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious. The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.

 

Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.

 

Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.

 

"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris. Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb.

 

Scrapie has been around for centuries and until now there has been no evidence that it poses a risk to human health. But if the French finding means that scrapie can cause sCJD in people, countries around the world may have overlooked a CJD crisis to rival that caused by BSE.

 

Deslys and colleagues were originally studying vCJD, not sCJD. They injected the brains of macaque monkeys with brain from BSE cattle, and from French and British vCJD patients. The brain damage and clinical symptoms in the monkeys were the same for all three. Mice injected with the original sets of brain tissue or with infected monkey brain also developed the same symptoms.

 

As a control experiment, the team also injected mice with brain tissue from people and animals with other prion diseases: a French case of sCJD; a French patient who caught sCJD from human-derived growth hormone; sheep with a French strain of scrapie; and mice carrying a prion derived from an American scrapie strain. As expected, they all affected the brain in a different way from BSE and vCJD. But while the American strain of scrapie caused different damage from sCJD, the French strain produced exactly the same pathology.

 

"The main evidence that scrapie does not affect humans has been epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute for Animal Health in Edinburgh, who was a member of the same team as Deslys. "You see about the same incidence of the disease everywhere, whether or not there are many sheep, and in countries such as New Zealand with no scrapie." In the only previous comparisons of sCJD and scrapie in mice, Bruce found they were dissimilar.

 

But there are more than 20 strains of scrapie, and six of sCJD. "You would not necessarily see a relationship between the two with epidemiology if only some strains affect only some people," says Deslys. Bruce is cautious about the mouse results, but agrees they require further investigation. Other trials of scrapie and sCJD in mice, she says, are in progress.

 

People can have three different genetic variations of the human prion protein, and each type of protein can fold up two different ways. Kretschmar has found that these six combinations correspond to six clinical types of sCJD: each type of normal prion produces a particular pathology when it spontaneously deforms to produce sCJD.

 

But if these proteins deform because of infection with a disease-causing prion, the relationship between pathology and prion type should be different, as it is in vCJD. "If we look at brain samples from sporadic CJD cases and find some that do not fit the pattern," says Kretschmar, "that could mean they were caused by infection."

 

There are 250 deaths per year from sCJD in the US, and a similar incidence elsewhere. Singeltary and other US activists think that some of these people died after eating contaminated meat or "nutritional" pills containing dried animal brain. Governments will have a hard time facing activists like Singeltary if it turns out that some sCJD isn't as spontaneous as doctors have insisted.

 

Deslys's work on macaques also provides further proof that the human disease vCJD is caused by BSE. And the experiments showed that vCJD is much more virulent to primates than BSE, even when injected into the bloodstream rather than the brain. This, says Deslys, means that there is an even bigger risk than we thought that vCJD can be passed from one patient to another through contaminated blood transfusions and surgical instruments.

 


 

Friday, January 30, 2015

 

*** Scrapie: a particularly persistent pathogen ***

 


 

 >>> genotypes ARR/ARQ and ARR/ARR are resistant

 

Resistance to scrapie in PrP ARR/ARQ heterozygous sheep is not caused by preferential allelic use

 

P A Caplazi, K I O’Rourke, T V Baszler

 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

 

J Clin Pathol 2004;57:647–650. doi: 10.1136/jcp.2003.012203

 

Background: In sheep, susceptibility to scrapie, which is similar to human prion diseases such as Kuru and variant Creutzfeldt-Jakob disease (vCJD), is determined by prion protein (PrP) gene (Prnp) polymorphisms. Sheep with genotype ARQ/ARQ, denoting polymorphisms at codons 136, 154, and 171, are susceptible, whereas those with genotypes ARR/ARQ and ARR/ARR are resistant, indicating dominance of ARR over the ARQ allele.

 

Aims: Based on familial CJD E200K, 129V, where preferential use of the 200E allele in EK heterozygous individuals confers resistance, heterozygous ARR/ARQ sheep were used to test the hypothesis that resistance is caused by preferential use of the ARR allele.

 

Methods: After assessment of equivalent PrP expression across genotypes, allele use was analysed by sequencing reverse transcription polymerase chain reaction derived DNA clones containing the Prnp gene coding sequence. Results: The ARR to ARQ ratio was 1.1 in 133 clones, representing Prnp mRNA from three ARR/ARQ sheep, indicating equal use of both alleles.

 

Conclusions: Dominance of the resistant associated allele in sheep scrapie involves mechanisms other than the absence of PrP derived from the disease associated ARQ allele.

 


 

>>>We report here the identification and characterization of 2 natural classic scrapie cases in sheep of the ARR/ARR genotype, which are clearly different from BSE and atypical scrapie.

 

 Classic Scrapie in Sheep with the ARR/ARR Prion Genotype in Germany and France

 

Martin H. Groschup,*1 Caroline Lacroux,†1 Anne Buschmann,* Gesine Lühken,‡ Jacinthe Mathey,† Martin Eiden,* Séverine Lugan,† Christine Hoffmann,* Juan Carlos Espinosa,§ Thierry Baron,¶ Juan Maria Torres,§ Georg Erhardt,‡ and Olivier Andreoletti†

 

In the past, natural scrapie and bovine spongiform encephalopathy (BSE) infections have essentially not been diagnosed in sheep homozygous for the A136R154R171 haplotype of the prion protein. This genotype was therefore assumed to confer resistance to BSE and classic scrapie under natural exposure conditions. Hence, to exclude prions from the human food chain, massive breeding efforts have been undertaken in the European Union to amplify this gene. We report the identifi cation of 2 natural scrapie cases in ARR/ARR sheep that have biochemical and transmission characteristics similar to cases of classic scrapie, although the abnormally folded prion protein (PrPSc) was associated with a lower proteinase-K resistance. PrPSc was clearly distinct from BSE prions passaged in sheep and from atypical scrapie prions. These findings strongly support the idea that scrapie prions are a mosaic of agents, which harbor different biologic properties, rather than a unique entity.

 

snip...

 

However, the successful transmission of BSE prions to ARR/ARR sheep showed that the resistance of this genotype toward the TSE agent was not absolute (11). Recently, the identification of previously unrecognized so-called atypical scrapie in sheep of various genotypes, including ARR/ARR, has reinforced this statement (4).

 

***We report here the identification and characterization of 2 natural classic scrapie cases in sheep of the ARR/ARR genotype, which are clearly different from BSE and atypical scrapie.

 

snip...

 

see full text ;

 


 

2011-06-16-110 Prion disease update 2011 (06) To: (06) Transmissible spongiform encephalopathies ************************************************* PRION DISEASE UPDATE 2011 (06) ****************************** A ProMED-mail post <http://www.promedmail.org>

 


 

Archive Number 20100312.0803 Published Date 12-MAR-2010 Subject PRO/AH/EDR> Scrapie, atypical, ovine - Australia: (WA) susp

 

SCRAPIE, ATYPICAL, OVINE - AUSTRALIA: (WESTERN AUSTRALIA) SUSPECTED

 

*******************************************************************

 

A ProMED-mail post

 

ProMED-mail is a program of the International Society for Infectious Diseases

 

[1] Date: Fri 12 Mar 2010 Source: The Australian [edited]

 

 A West Australian sheep has been found to have signs characteristic of the fatal brain disease atypical scrapie. It comes as Australia faces growing anger from its trade partners over the Rudd government's surprise decision to extend a ban on the importation of beef from countries exposed to mad cow disease for a further 2 years.

 

Australia's chief veterinarian, Andy Carroll, told the ABC an indicative case of the atypical scrapie had been confirmed but said it posed no risk to human or animal health or the safety of eating meat and animal products.

 

Nor does atypical scrapie carry the dire trade consequences associated with classical scrapie.

 

Classical scrapie is in the same transmissible spongiform encephalopathies (TSE) family as BSE, better known as mad cow disease, from which humans can be fatally infected.

 

Dr Carroll said samples from the sheep's brain were being sent to the World Reference Laboratory in Britain.

 

Neither atypical scrapie nor classical scrapie has been seen in Australia before, but a sheep in New Zealand tested positive to the atypical form last year [2009].

 

Atypical scrapie is a relatively recently discovered disease and the common scientific view is that it occurs spontaneously or naturally in very small numbers of older sheep in countries all over the world.

 

[Byline: Jodie Minus]

 

-- Communicated by: Sabine Zentis Castleview Pedigree English Longhorns Gut Laach 52385 Nideggen Germany

 

****** [2] Date: Wed 10 Mar 2010 Source: ABC News (Australian Broadcasting Corporation) [edited]

 

Animal health authorities are testing a sheep's brain for what could be Australia's 1st case of the disease atypical scrapie.

 

Although not confirmed, the sheep is thought to be from Western Australia.

 

This type of scrapie is described as a sporadic degenerative brain condition affecting older sheep, and is not contagious.

 

Ed Klim, from national advisory group SafeMeat, says a 2nd round of testing is now taking place. "We've been made aware that the Australian Animal Health Laboratory is conducting further routine testing on a sheep sample," he says.

 

"The disease isn't considered a health risk nor should have any impact on food safety or export markets for sheep meat of live sheep."

 

Australia's chief veterinarian and WA's Department of Agriculture of Food are both aware of the testing but will not comment.

 

-- Communicated by: Terry S Singeltary Sr

 

[Although atypical scrapie is not yet ruled out, it is important to realize this is a type of scrapie that thus far has only tended to appear as a sporadic condition in older animals. Currently it has not been shown to follow the same genetic tendencies for propagation as the usual scrapie.

 

However, the atypical phenotypic appearance has been shown to be preserved on experimental passage.

 

Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries, as Australia may join that list. It is likely that this case will be sent to the UK for definitive conformation.

 

[Ref: M Simmons, T Konold, L Thurston, et al. BMC Veterinary Research 2010, 6:14 [provisional abstract available at ]

 

"Background ----------- "Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. [Many of the neurological diseases can be transmitted by intracerebral inoculation, which causes this moderator to approach intracerebral studies as a tool for study, but not necessarily as a direct indication of transmissibility of natural diseases. - Mod.TG]

 

"The 1st successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.

 

"Results -------- "This study demonstrates that atypical scrapie has distinct clinical, pathological, and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.

 

"Conclusions ------------ Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage."

 

Lastly, this moderator wishes to thank Terry Singletary for some of his behind the scenes work of providing citations and references for this posting. - Mod.TG]

 

The HealthMap/ProMED-mail interactive map of Australia is available at . - Sr.Tech.Ed.MJ]

 


 

 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.

 


 

 snip...

 



 

Sunday, August 19, 2012

 

Susceptibility of cattle to the agent of chronic wasting disease from elk after intracranial inoculation 2012

 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research Unit

 


 

Thursday, November 21, 2013

 

*** Assessing the susceptibility of transgenic mice over-expressing deer prion protein to bovine spongiform encephalopathy

 

The present study was designed to assess the susceptibility of the prototypic mouse line, Tg(CerPrP)1536+/- to bovine spongiform encephalopathy (BSE) prions, which have the ability to overcome species barriers. Tg(CerPrP)1536+/- mice challenged with red deer-adapted BSE resulted in a 90-100% attack rates, BSE from cattle failed to transmit, indicating agent adaptation in the deer.

 


 

*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.

 


 

NOW, what is the latest on human risk factors to CWD strains ???

 

*** PPo3-7: Prion Transmission from Cervids to Humans is Strain-dependent

 

*** Here we report that a human prion strain that had adopted the cervid prion protein (PrP) sequence through passage in cervidized transgenic mice efficiently infected transgenic mice expressing human PrP,

 

*** indicating that the species barrier from cervid to humans is prion strain-dependent and humans can be vulnerable to novel cervid prion strains.

 

PPo2-27:

 

Generation of a Novel form of Human PrPSc by Inter-species Transmission of Cervid Prions

 

*** Our findings suggest that CWD prions have the capability to infect humans, and that this ability depends on CWD strain adaptation, implying that the risk for human health progressively increases with the spread of CWD among cervids.

 

PPo2-7:

 

Biochemical and Biophysical Characterization of Different CWD Isolates

 

*** The data presented here substantiate and expand previous reports on the existence of different CWD strains.

 


 

Envt.07:

 

Pathological Prion Protein (PrPTSE) in Skeletal Muscles of Farmed and Free Ranging White-Tailed Deer Infected with Chronic Wasting Disease

 

***The presence and seeding activity of PrPTSE in skeletal muscle from CWD-infected cervids suggests prevention of such tissue in the human diet as a precautionary measure for food safety, pending on further clarification of whether CWD may be transmissible to humans.

 


 

>>>CHRONIC WASTING DISEASE , THERE WAS NO ABSOLUTE BARRIER TO CONVERSION OF THE HUMAN PRION PROTEIN<<<

 

*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***

 

Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014

 

Wednesday, January 01, 2014

 

Molecular Barriers to Zoonotic Transmission of Prions

 

*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.

 

*** Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype.

 


 


 

PRION2013 CONGRESSIONAL ABSTRACTS CWD

 

Sunday, August 25, 2013

 

HD.13: CWD infection in the spleen of humanized transgenic mice

 

***These results indicate that the CWD prion may have the potential to infect human peripheral lymphoid tissues.

 

Oral.15: Molecular barriers to zoonotic prion transmission: Comparison of the ability of sheep, cattle and deer prion disease isolates to convert normal human prion protein to its pathological isoform in a cell-free system ***However, they also show that there is no absolute barrier to conversion of human prion protein in the case of chronic wasting disease.

 

PRION2013 CONGRESSIONAL ABSTRACTS CWD

 

Sunday, August 25, 2013

 

***Chronic Wasting Disease CWD risk factors, humans, domestic cats, blood, and mother to offspring transmission

 


 

there is in fact evidence that the potential for cwd transmission to humans can NOT be ruled out.

 

I thought your readers and hunters and those that consume the venison, should have all the scientific facts, personally, I don’t care what you eat, but if it effects me and my family down the road, it should then concern everyone, and the potential of iatrogenic transmission of the TSE prion is real i.e. ‘friendly fire’, medical, surgical, dental, blood, tissue, and or products there from...like deer antler velvet and TSE prions and nutritional supplements there from, all a potential risk factor that should not be ignored or silenced. ...

 

the prion gods at the cdc state that there is ;

 

''no strong evidence''

 

but let's see exactly what the authors of this cwd to human at the cdc state ;

 

now, let’s see what the authors said about this casual link, personal communications years ago. see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????

 

“Our conclusion stating that we found no strong evidence of CWD transmission to humans”

 

From: TSS (216-119-163-189.ipset45.wt.net)

 

Subject: CWD aka MAD DEER/ELK TO HUMANS ???

 

Date: September 30, 2002 at 7:06 am PST

 

From: "Belay, Ermias"

 

To:

 

Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"

 

Sent: Monday, September 30, 2002 9:22 AM

 

Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Dear Sir/Madam,

 

In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.

 

That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.

 

Ermias Belay, M.D. Centers for Disease Control and Prevention

 

-----Original Message-----

 

From:

 

Sent: Sunday, September 29, 2002 10:15 AM

 

To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV

 

Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS

 

Thursday, April 03, 2008

 

A prion disease of cervids: Chronic wasting disease

 

2008 1: Vet Res. 2008 Apr 3;39(4):41

 

A prion disease of cervids: Chronic wasting disease

 

Sigurdson CJ.

 

snip...

 

*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,

 

snip...

 

full text ;

 


 


 


 

***********CJD REPORT 1994 increased risk for consumption of veal and venison and lamb***********

 

CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994

 

Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss)

 

These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...

 

Table 9 presents the results of an analysis of these data.

 

There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).

 

Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.

 

There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).

 

The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).

 

There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).

 

The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).

 

snip...

 

It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).

 

snip...

 

In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...

 

snip...

 

In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)

 

snip...see full report ;

 


 

Thursday, October 10, 2013

 

*************CJD REPORT 1994 increased risk for consumption of veal and venison and lamb**************

 


 

CJD9/10022

 

October 1994

 

Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane BerksWell Coventry CV7 7BZ

 

Dear Mr Elmhirst,

 

CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT

 

Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.

 

The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.

 

The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.

 

The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.

 

I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.

 


 

*** our results raise the possibility that CJD cases classified as VV1 may include cases caused by iatrogenic transmission of sCJD-MM1 prions or food-borne infection by type 1 prions from animals, e.g., chronic wasting disease prions in cervid. In fact, two CJD-VV1 patients who hunted deer or consumed venison have been reported (40, 41). The results of the present study emphasize the need for traceback studies and careful re-examination of the biochemical properties of sCJD-VV1 prions. ***

 


 

snip...see full text ;

 


 

Thursday, January 2, 2014

 

*** CWD TSE Prion in cervids to hTGmice, Heidenhain Variant Creutzfeldt-Jacob Disease MM1 genotype, and iatrogenic CJD ??? ***

 


 

*** We hypothesize that both BSE prions and CWD prions passaged through felines will seed human recPrP more efficiently than BSE or CWD from the original hosts, evidence that the new host will dampen the species barrier between humans and BSE or CWD. The new host effect is particularly relevant as we investigate potential means of trans-species transmission of prion disease.

 


 

Monday, August 8, 2011

 

*** Susceptibility of Domestic Cats to CWD Infection ***

 

Oral.29: Susceptibility of Domestic Cats to CWD Infection

 

Amy Nalls, Nicholas J. Haley, Jeanette Hayes-Klug, Kelly Anderson, Davis M. Seelig, Dan S. Bucy, Susan L. Kraft, Edward A. Hoover and Candace K. Mathiason†

 

Colorado State University; Fort Collins, CO USA†Presenting author; Email: ckm@lamar.colostate.edu

 

Domestic and non-domestic cats have been shown to be susceptible to one prion disease, feline spongiform encephalopathy (FSE), thought to be transmitted through consumption of bovine spongiform encephalopathy (BSE) contaminated meat. Because domestic and free ranging felids scavenge cervid carcasses, including those in CWD affected areas, we evaluated the susceptibility of domestic cats to CWD infection experimentally. Groups of n = 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD deer brain homogenate. Between 40–43 months following IC inoculation, two cats developed mild but progressive symptoms including weight loss, anorexia, polydipsia, patterned motor behaviors and ataxia—ultimately mandating euthanasia. Magnetic resonance imaging (MRI) on the brain of one of these animals (vs. two age-matched controls) performed just before euthanasia revealed increased ventricular system volume, more prominent sulci, and T2 hyperintensity deep in the white matter of the frontal hemisphere and in cortical grey distributed through the brain, likely representing inflammation or gliosis. PrPRES and widely distributed peri-neuronal vacuoles were demonstrated in the brains of both animals by immunodetection assays. No clinical signs of TSE have been detected in the remaining primary passage cats after 80 months pi. Feline-adapted CWD was sub-passaged into groups (n=4 or 5) of cats by IC, PO, and IP/SQ routes. Currently, at 22 months pi, all five IC inoculated cats are demonstrating abnormal behavior including increasing aggressiveness, pacing, and hyper responsiveness.

 

*** Two of these cats have developed rear limb ataxia. Although the limited data from this ongoing study must be considered preliminary, they raise the potential for cervid-to-feline transmission in nature.

 


 


 

AD.63:

 

Susceptibility of domestic cats to chronic wasting disease

 

Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1 1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA

 

Domestic and nondomestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging nondomestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated cats developed signs consistent with prion disease, including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns consistent with the early stage of feline CWD.

 

*** These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to- feline transmission in nature.

 


 

www.landesbioscience.com

 

PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)

 


 


 

FELINE SPONGIFORM ENCEPHALOPATHY FSE

 


 


 

Saturday, January 31, 2015

 

European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route

 


 

*** Singeltary reply ;

 

ruminant feed ban for cervids in the United States ?

 

31 Jan 2015 at 20:14 GMT

 


 

Friday, January 30, 2015

 

*** Scrapie: a particularly persistent pathogen ***

 


 

Tuesday, January 06, 2015

 

APHIS Provides Additional Information on Chronic Wasting Disease (CWD) Indemnity Requests January 5, 2015 05:26 PM EST

 


 


 

 

TSS

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