Sunday, March 29, 2015

Uncommon prion disease induced in macaque ten years after scrapie inoculation

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J. Mikol1, S. Luccantoni-Freire1, E. Correia1, N. Lescoutra-Etchegaray1, V. Durand1, C. Dehen1, J.P. Deslys1, E. Comoy1

 

1Institute of Emerging Diseases and Innovative Therapies, Service of Prion Diseases, Atomic Energy Commission, 18 Route du Panorama 92265 Fontenayaux- Roses, France

 

E-mail: jacqueline.mikol@wanadoo.fr

 

Uncommon prion disease induced in macaque ten years after scrapie inoculation

 

Introduction: Bovine Spongiform Encephalopathy (BSE) is the single animal prion disease reputed to be zoonotic, inducing variant of Creutzfeldt-Jakob Disease (vCJD) in man, and therefore strongly conditioned the protective measures. Among different sources of animal prion diseases, we show here that after more than ten years of incubation, intracerebral injection of a sheep scrapie isolate can induce a prion disease in cynomolgus macaque, a relevant model of human situation towards several prion strains. Neuropathological studies showed classical and uncommon data.

 

Material and method: The cynomolgus macaque was intracerebrally exposed to a classical scrapie isolate issued from a naturally infected sheep flock. Upon onset of clinical signs, euthanasia was performed for ethical reasons. Classical methods of biochemistry and neuropathology were used.

 

Results: The three elements of the triad were present:

 

spongiosis was predominant in the cortex, the striatum, the cerebellum. Neuronal loss and gliosis were moderate.

 

The notable data were the following

 

(i) the brain was small, the atrophy involved mostly the temporal lobe in which axonal loss was histologically demonstrated

 

(ii) the spongiosis of the Purkinje cells was so intense that most of them were destroyed

 

(iii) there was a neuronal loss and a massive gliosis of the dorsomedialis nucleus of the thalamus

 

(iv) iron deposits were present in the lenticular nucleus. PrPres heavily distributed in the cortex, the basal ganglia and the cerebellum consisted in synaptic deposits and aggregates. Western Blot exhibited a type 1 PrPres in all parts of the brain.

 

Conclusion: We described here the successful transmission of a scrapie prion disease to a non-human primate after an extended incubation period, leading to a fatal, non-relapsing neurological disease with all the features of a prion disease. The cerebral lesional profile we observed was original in comparison to other animal prion diseases (c-BSE, L-type BSE, TME) we previously experimentally transmitted in this model.

 


 

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 ***

 


 

Thursday, March 26, 2015

 

Increased Infectivity of Anchorless Mouse Scrapie Prions in Transgenic Mice Overexpressing Human Prion Protein

 


 

Thursday, March 26, 2015

 

National Scrapie Eradication Program Monthly Report - February 2015

 


 

Thursday, March 26, 2015

 

Variant CJD and blood transfusion: are there additional cases?

 

Vox Sanguinis (2014) 107, 220–225 ORIGINAL PAPER © 2014 International Society of Blood Transfusion DOI: 10.1111/vox.12161

 



Sunday, May 18, 2008

MAD COW DISEASE BSE CJD CHILDREN VACCINES

http://bseinquiry.blogspot.com/2008/05/mad-cow-disease-bse-cjd-children.html

 


 


 

 

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