Pathogens. 2022 May 20;11(5):597. doi: 10.3390/pathogens11050597
Experimental Bovine Spongiform Encephalopathy in Squirrel Monkeys: The Same Complex Proteinopathy Appearing after Very Different Incubation Times
Pedro Piccardo 1,2,3, Juraj Cervenak 1, Wilfred Goldmann 2,†, Paula Stewart 2, Kitty L Pomeroy 1,‡, Luisa Gregori 1, Oksana Yakovleva 1, David M Asher 1,*,† Editor: Pawel P Liberski
PMCID: PMC9144249 PMID: 35631118
Abstract
Incubation periods in humans infected with transmissible spongiform encephalopathy (TSE) agents can exceed 50 years. In humans infected with bovine spongiform encephalopathy (BSE) agents, the effects of a “species barrier,” often observed when TSE infections are transmitted from one species to another, would be expected to increase incubation periods compared with transmissions of same infectious agents within the same species. As part of a long-term study investigating the susceptibility to BSE of cell cultures used to produce vaccines, we inoculated squirrel monkeys (Saimiri sp., here designated SQ) with serial dilutions of a bovine brain suspension containing the BSE agent and monitored them for as long as ten years. Previously, we showed that SQ infected with the original “classical” BSE agent (SQ-BSE) developed a neurological disease resembling that seen in humans with variant CJD (vCJD). Here, we report the final characterization of the SQ-BSE model. We observed an unexpectedly marked difference in incubation times between two animals inoculated with the same dilution and volume of the same C-BSE bovine brain extract on the same day. SQ-BSE developed, in addition to spongiform changes and astrogliosis typical of TSEs, a complex proteinopathy with severe accumulations of protease-resistant prion protein (PrPTSE), hyperphosphorylated tau (p-tau), ubiquitin, and α-synuclein, but without any amyloid plaques or β-amyloid protein (Aβ) typical of Alzheimer’s disease. These results suggest that PrPTSE enhanced the accumulation of several key proteins characteristically seen in human neurodegenerative diseases. The marked variation in incubation periods in the same experimental TSE should be taken into account when modeling the epidemiology of human TSEs.
snip…
The epidemic of BSE in UK cattle in the 1980s and 90s was followed by a relatively modest number of diagnosed cases of vCJD (233 total cases worldwide—all but 55 in the UK—as of May 2022, reported by the UK CJD Research and Surveillance Unit, Edinburgh [www.cjd.ed/uk], accessed on 12 May 2022), among tens of millions of people probably exposed to the agent. That observation raised questions about the overall transmissibility of the agent to humans and the possible existence of some unknown number of latent or asymptomatic cases of vCJD [2]. Experiments in monkeys—large long-lived animals genetically more closely related to humans than are rodents and ruminants—might help to address some of those issues. Studies in monkeys might also help to elucidate the possible role that aggregates of brain proteins other than PrP play in pathology and pathogenesis of various human TSEs [10]. As part of a long-term study investigating susceptibility of several widely used cell cultures to BSE infection, we inoculated squirrel monkeys (SQ) with serial dilutions of a bovine brain suspension containing the C-BSE agent and monitored them for ten years. In a preliminary study, we showed that SQ infected with C-BSE (SQ-BSE) developed a spongiform encephalopathy resembling that seen in humans with vCJD [10,11], albeit without PrP plaques. Here, we report the final characterization of this experimental model after observation over ten years. We observed an unexpected extreme difference in incubation times between two animals inoculated with the same dilution and volume of a C-BSE brain suspension on the same day. SQ-BSE developed, in addition to spongiform changes and astrogliosis, a complex proteinopathy with severe accumulations of PrPTSE, hyperphosphorylated tau (p-tau), ubiquitin, and α-synuclein but without the beta-amyloid (Aβ) protein typical of Alzheimer’s disease.
2. Results
2.1. Seven Squirrel Monkeys Inoculated with Material Containing BSE Agent Developed a Similar Neurological Disease (SQ-BSE) after Significantly Different Incubation Times Compared to Four Uninfected Squirrel Monkeys (SQ-Uninfected)
We previously showed that transgenic mice expressing bovine PrP (TgBo) inoculated with a bacteria-free filtrate of the same 1% C-BSE-infected brain suspension used to inoculate SQ developed neurological signs confirmed neuropathologically as TSE [11]. Those preliminary studies demonstrated that the original C-BSE brain extract used in the experiments described here contained infectivity (5 log10 IC ID50 per 0.03 mL). SQ were inoculated with serial dilutions of the same material used to inoculate TgBo mice. Ten years after inoculation the experiment was terminated.
Seven monkeys, designated SQ-BSE, developed neurologic signs typical of TSE, including loss of normal responsiveness (withdrawal), tremor, bradykinesia, jerky uncoordinated movements, and generalized weakness. No monkeys became noticeably irritable or aggressive and none lost weight. Three animals inoculated with 10−1 (10%) unfiltered low-speed clarified C-BSE agent were euthanized ~3.2 years (~38.4 months) after inoculation. Two animals inoculated with 10−2 unfiltered, low-speed clarified C-BSE suspension were euthanized 3.7 years (44.4 months) after inoculation. Two animals inoculated with the 0.45-µm-filtered bacteria-free 10−2 C-BSE-infected brain suspension also developed TSE. One of those animals (SQ-BSE 735) was euthanized with signs of TSE 3.3 years (39.6 months) after inoculation. SQ-BSE 735’s cage mate (736) had been inoculated by the same investigator with the same dilution and volume of C-BSE inoculum, on the same day and in the same facility used to inoculate all other animals described here; SQ-BSE 736 developed similar signs of neurological illness including weakness and ataxia, but almost five years (60 months) later (a total of 7.9 years [94.8 months] after inoculation). SQ-BSE 736’s neurological disease progressed over a period of 50 days until the animal was euthanized. Both SQ-BSE 735 and SQ-BSE 736 showed similar neurological signs and durations of overt illness (Table 1). All other animals inoculated with dilutions of BSE brain extract diluted > 10−2 remained asymptomatic until the experiment was terminated.
Snip…
3. Discussion Although squirrel monkeys have long been recognized as susceptible to infection with several TSE agents [2,14] transmission of BSE into this species has not been reported by other research groups [15]. The results presented here, after a ten-year observation period, show that intracerebral and peripheral inoculation of C-BSE agent into SQ transmitted a neurological disease with progressive behavioral, motor and cerebellar signs typical of TSEs. Neuropathologic examinations of brains from all seven animals with experimental BSE showed similar severe spongiform degeneration in the cerebrum, cerebellum and brainstem. Abundant PrPTSE deposits were present in most brain areas analyzed, closely correlated with severity of spongiform degeneration and astrogliosis. However, no obvious spongiform degeneration or PrP accumulation occurred in the temporal cortex; the hippocampus showed only minimal PrPTSE accumulation in the CA1 area. Brains of all animals with BSE showed severe tauopathy (in cerebral cortex, basal ganglia, cerebellum and brainstem) in the same areas with spongiform degeneration, PrPTSE, and astrogliosis, suggesting a correlation between neurodegeneration and complex protein accumulation in SQ-BSE. The morphology and distribution of p-tau deposits differ from those seen in humans with Alzheimer’s disease and with primary tauopathies [16]. However, p-tau rods similar to those described here have been described in other experimental TSEs, in humans with vCJD [16,17,18,19] and in a non-transmitted encephalopathy of UK cattle [20]. Our findings suggest that p-tau probably accumulated as a secondary event following appearance of spongiform encephalopathy and accumulation of PrPTSE. While it would have been interesting to study early development of the several histopathologic changes and accumulation of proteins during the silent incubation period of experimental BSE, especially the temporal relationship in appearance and accumulation of PrPTSE and p-tau, the study was not designed for that purpose and it was not feasible. Although p-tau is considered a neuropathologic hallmark in several degenerative diseases of the central nervous system, tau protein displays other post-translational modifications (e.g., glycosylation, acetylation), raising a possibility that other tau species might also participate in the disease process [21]. No obvious differences in distribution of PrPTSE and p-tau deposits or in astrogliosis were observed in SQ-BSE after incubation periods ranging from 29 to 98.6 months or in those with different durations of clinical signs ranging from two to five months. We did find larger amounts of PrPTSE, astrogliosis, p-tau, and α-synuclein in the brain of SQ-BSE 736 compared with SQ-BSE 735, suggesting that more post-translationally modified proteins accumulated during the longer asymptomatic phase of BSE. The extended incubation period in SQ-BSE 736 underscores one limitation of rodent models expressing human PrP to assess pathogenesis of human later-onset TSEs—that most mice rarely live much longer than two years. The severe pathology seen in the brainstem and the cerebellum of SQ-BSE is of special interest. Most patients become demented in the terminal stages of many neurodegenerative diseases; consequently, postmortem studies of their brains have usually directed special attention to lesions in the telencephalon (supratentorial) while rather neglecting degenerative changes in brainstem and cerebellum. Further studies should explore whether loss of cortical neurons in TSEs causes secondary infratentorial pathology or if infratentorial regions are also a primary target of disease. Additional studies might also determine to what extent the nuclei of the brainstem (essential to maintain vital neurological functions) affected by neurodegenerative processes in TSEs contribute to the rapid clinical decline typical of TSEs. Recent studies of early AD and PD also found considerable unexpected involvement of brainstem nuclei, findings that might profoundly change present concepts on origin, anatomical spread, and early clinical diagnosis of these diseases [22]. Previous studies suggest that a disturbed insulin signaling cascade may be implicated in the pathways through which soluble Aβ protein induces tau protein to phosphorylate [23]. Vasconcelos concluded that Aβ induced heterotypic seeding of tau filaments by spread of abnormal tau isoforms [24], possibly because hyperphosphorylation of tau, leads to self-assembly [25]. Here, we report that both p-tau and α-synuclein accumulated in all the same brain areas with neurodegeneration, but without forming detectable Aβ-amyloid plaques. Those findings suggest that subfibrillary PrPTSE aggregates might have stimulated a complex proteinopathy involving both tau and α-synuclein proteins that actively contributed to pathogenesis, perhaps resulting from loss of some function of PrPC. An incidental finding of significance in the study is that differences in incubation times of BSE in SQ cannot be attributed to variation in the open reading frames of PRNP genes because those sequences were identical in all monkeys tested; any genetic differences influencing incubation times must reside elsewhere in the genome. Furthermore, these results suggest caution before relying on similarities or differences in PrPTSE glycotype to infer that a TSE infection in one species was acquired from a TSE agent originating in the same or another species, because PrP of three species infected with the classical C-BSE agent in our study displayed different glycotypes. In any case, results with the SQ-BSE model presented here affirm that primate models can improve our understanding of the pathogenesis of human neurodegenerative diseases.
Keywords: prion, TSE, bovine spongiform encephalopathy, squirrel monkey
https://pmc.ncbi.nlm.nih.gov/articles/PMC9144249/
Pedro Piccardo 1,2,3, Juraj Cervenak 1, Wilfred Goldmann 2,†, Paula Stewart 2, Kitty L Pomeroy 1,‡, Luisa Gregori 1, Oksana Yakovleva 1, David M Asher 1,*,† Editor: Pawel P Liberski
PMCID: PMC9144249 PMID: 35631118
Abstract
Incubation periods in humans infected with transmissible spongiform encephalopathy (TSE) agents can exceed 50 years. In humans infected with bovine spongiform encephalopathy (BSE) agents, the effects of a “species barrier,” often observed when TSE infections are transmitted from one species to another, would be expected to increase incubation periods compared with transmissions of same infectious agents within the same species. As part of a long-term study investigating the susceptibility to BSE of cell cultures used to produce vaccines, we inoculated squirrel monkeys (Saimiri sp., here designated SQ) with serial dilutions of a bovine brain suspension containing the BSE agent and monitored them for as long as ten years. Previously, we showed that SQ infected with the original “classical” BSE agent (SQ-BSE) developed a neurological disease resembling that seen in humans with variant CJD (vCJD). Here, we report the final characterization of the SQ-BSE model. We observed an unexpectedly marked difference in incubation times between two animals inoculated with the same dilution and volume of the same C-BSE bovine brain extract on the same day. SQ-BSE developed, in addition to spongiform changes and astrogliosis typical of TSEs, a complex proteinopathy with severe accumulations of protease-resistant prion protein (PrPTSE), hyperphosphorylated tau (p-tau), ubiquitin, and α-synuclein, but without any amyloid plaques or β-amyloid protein (Aβ) typical of Alzheimer’s disease. These results suggest that PrPTSE enhanced the accumulation of several key proteins characteristically seen in human neurodegenerative diseases. The marked variation in incubation periods in the same experimental TSE should be taken into account when modeling the epidemiology of human TSEs.
snip…
The epidemic of BSE in UK cattle in the 1980s and 90s was followed by a relatively modest number of diagnosed cases of vCJD (233 total cases worldwide—all but 55 in the UK—as of May 2022, reported by the UK CJD Research and Surveillance Unit, Edinburgh [www.cjd.ed/uk], accessed on 12 May 2022), among tens of millions of people probably exposed to the agent. That observation raised questions about the overall transmissibility of the agent to humans and the possible existence of some unknown number of latent or asymptomatic cases of vCJD [2]. Experiments in monkeys—large long-lived animals genetically more closely related to humans than are rodents and ruminants—might help to address some of those issues. Studies in monkeys might also help to elucidate the possible role that aggregates of brain proteins other than PrP play in pathology and pathogenesis of various human TSEs [10]. As part of a long-term study investigating susceptibility of several widely used cell cultures to BSE infection, we inoculated squirrel monkeys (SQ) with serial dilutions of a bovine brain suspension containing the C-BSE agent and monitored them for ten years. In a preliminary study, we showed that SQ infected with C-BSE (SQ-BSE) developed a spongiform encephalopathy resembling that seen in humans with vCJD [10,11], albeit without PrP plaques. Here, we report the final characterization of this experimental model after observation over ten years. We observed an unexpected extreme difference in incubation times between two animals inoculated with the same dilution and volume of a C-BSE brain suspension on the same day. SQ-BSE developed, in addition to spongiform changes and astrogliosis, a complex proteinopathy with severe accumulations of PrPTSE, hyperphosphorylated tau (p-tau), ubiquitin, and α-synuclein but without the beta-amyloid (Aβ) protein typical of Alzheimer’s disease.
2. Results
2.1. Seven Squirrel Monkeys Inoculated with Material Containing BSE Agent Developed a Similar Neurological Disease (SQ-BSE) after Significantly Different Incubation Times Compared to Four Uninfected Squirrel Monkeys (SQ-Uninfected)
We previously showed that transgenic mice expressing bovine PrP (TgBo) inoculated with a bacteria-free filtrate of the same 1% C-BSE-infected brain suspension used to inoculate SQ developed neurological signs confirmed neuropathologically as TSE [11]. Those preliminary studies demonstrated that the original C-BSE brain extract used in the experiments described here contained infectivity (5 log10 IC ID50 per 0.03 mL). SQ were inoculated with serial dilutions of the same material used to inoculate TgBo mice. Ten years after inoculation the experiment was terminated.
Seven monkeys, designated SQ-BSE, developed neurologic signs typical of TSE, including loss of normal responsiveness (withdrawal), tremor, bradykinesia, jerky uncoordinated movements, and generalized weakness. No monkeys became noticeably irritable or aggressive and none lost weight. Three animals inoculated with 10−1 (10%) unfiltered low-speed clarified C-BSE agent were euthanized ~3.2 years (~38.4 months) after inoculation. Two animals inoculated with 10−2 unfiltered, low-speed clarified C-BSE suspension were euthanized 3.7 years (44.4 months) after inoculation. Two animals inoculated with the 0.45-µm-filtered bacteria-free 10−2 C-BSE-infected brain suspension also developed TSE. One of those animals (SQ-BSE 735) was euthanized with signs of TSE 3.3 years (39.6 months) after inoculation. SQ-BSE 735’s cage mate (736) had been inoculated by the same investigator with the same dilution and volume of C-BSE inoculum, on the same day and in the same facility used to inoculate all other animals described here; SQ-BSE 736 developed similar signs of neurological illness including weakness and ataxia, but almost five years (60 months) later (a total of 7.9 years [94.8 months] after inoculation). SQ-BSE 736’s neurological disease progressed over a period of 50 days until the animal was euthanized. Both SQ-BSE 735 and SQ-BSE 736 showed similar neurological signs and durations of overt illness (Table 1). All other animals inoculated with dilutions of BSE brain extract diluted > 10−2 remained asymptomatic until the experiment was terminated.
Snip…
3. Discussion Although squirrel monkeys have long been recognized as susceptible to infection with several TSE agents [2,14] transmission of BSE into this species has not been reported by other research groups [15]. The results presented here, after a ten-year observation period, show that intracerebral and peripheral inoculation of C-BSE agent into SQ transmitted a neurological disease with progressive behavioral, motor and cerebellar signs typical of TSEs. Neuropathologic examinations of brains from all seven animals with experimental BSE showed similar severe spongiform degeneration in the cerebrum, cerebellum and brainstem. Abundant PrPTSE deposits were present in most brain areas analyzed, closely correlated with severity of spongiform degeneration and astrogliosis. However, no obvious spongiform degeneration or PrP accumulation occurred in the temporal cortex; the hippocampus showed only minimal PrPTSE accumulation in the CA1 area. Brains of all animals with BSE showed severe tauopathy (in cerebral cortex, basal ganglia, cerebellum and brainstem) in the same areas with spongiform degeneration, PrPTSE, and astrogliosis, suggesting a correlation between neurodegeneration and complex protein accumulation in SQ-BSE. The morphology and distribution of p-tau deposits differ from those seen in humans with Alzheimer’s disease and with primary tauopathies [16]. However, p-tau rods similar to those described here have been described in other experimental TSEs, in humans with vCJD [16,17,18,19] and in a non-transmitted encephalopathy of UK cattle [20]. Our findings suggest that p-tau probably accumulated as a secondary event following appearance of spongiform encephalopathy and accumulation of PrPTSE. While it would have been interesting to study early development of the several histopathologic changes and accumulation of proteins during the silent incubation period of experimental BSE, especially the temporal relationship in appearance and accumulation of PrPTSE and p-tau, the study was not designed for that purpose and it was not feasible. Although p-tau is considered a neuropathologic hallmark in several degenerative diseases of the central nervous system, tau protein displays other post-translational modifications (e.g., glycosylation, acetylation), raising a possibility that other tau species might also participate in the disease process [21]. No obvious differences in distribution of PrPTSE and p-tau deposits or in astrogliosis were observed in SQ-BSE after incubation periods ranging from 29 to 98.6 months or in those with different durations of clinical signs ranging from two to five months. We did find larger amounts of PrPTSE, astrogliosis, p-tau, and α-synuclein in the brain of SQ-BSE 736 compared with SQ-BSE 735, suggesting that more post-translationally modified proteins accumulated during the longer asymptomatic phase of BSE. The extended incubation period in SQ-BSE 736 underscores one limitation of rodent models expressing human PrP to assess pathogenesis of human later-onset TSEs—that most mice rarely live much longer than two years. The severe pathology seen in the brainstem and the cerebellum of SQ-BSE is of special interest. Most patients become demented in the terminal stages of many neurodegenerative diseases; consequently, postmortem studies of their brains have usually directed special attention to lesions in the telencephalon (supratentorial) while rather neglecting degenerative changes in brainstem and cerebellum. Further studies should explore whether loss of cortical neurons in TSEs causes secondary infratentorial pathology or if infratentorial regions are also a primary target of disease. Additional studies might also determine to what extent the nuclei of the brainstem (essential to maintain vital neurological functions) affected by neurodegenerative processes in TSEs contribute to the rapid clinical decline typical of TSEs. Recent studies of early AD and PD also found considerable unexpected involvement of brainstem nuclei, findings that might profoundly change present concepts on origin, anatomical spread, and early clinical diagnosis of these diseases [22]. Previous studies suggest that a disturbed insulin signaling cascade may be implicated in the pathways through which soluble Aβ protein induces tau protein to phosphorylate [23]. Vasconcelos concluded that Aβ induced heterotypic seeding of tau filaments by spread of abnormal tau isoforms [24], possibly because hyperphosphorylation of tau, leads to self-assembly [25]. Here, we report that both p-tau and α-synuclein accumulated in all the same brain areas with neurodegeneration, but without forming detectable Aβ-amyloid plaques. Those findings suggest that subfibrillary PrPTSE aggregates might have stimulated a complex proteinopathy involving both tau and α-synuclein proteins that actively contributed to pathogenesis, perhaps resulting from loss of some function of PrPC. An incidental finding of significance in the study is that differences in incubation times of BSE in SQ cannot be attributed to variation in the open reading frames of PRNP genes because those sequences were identical in all monkeys tested; any genetic differences influencing incubation times must reside elsewhere in the genome. Furthermore, these results suggest caution before relying on similarities or differences in PrPTSE glycotype to infer that a TSE infection in one species was acquired from a TSE agent originating in the same or another species, because PrP of three species infected with the classical C-BSE agent in our study displayed different glycotypes. In any case, results with the SQ-BSE model presented here affirm that primate models can improve our understanding of the pathogenesis of human neurodegenerative diseases.
Keywords: prion, TSE, bovine spongiform encephalopathy, squirrel monkey
https://pmc.ncbi.nlm.nih.gov/articles/PMC9144249/
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
http://collections.europarchive.org/tna/20080102222950/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
snip...
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease. PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously. snip... 76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis)
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
http://www.nature.com/nature/journal/v236/n5341/abs/236073a0.html
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References:
Dear Terry,
An excellent piece of review as this literature is desperately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currently then you wont find any!
Steve Dealler
====
''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).''
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 ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 1933-690X
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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
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 humanprion 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
http://www.nature.com/ncomms/2014/141216/ncomms6821/full/ncomms6821.html
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease. PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously. snip... 76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis)
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
http://www.nature.com/nature/journal/v236/n5341/abs/236073a0.html
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References:
Dear Terry,
An excellent piece of review as this literature is desperately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currently then you wont find any!
Steve Dealler
====
''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).''
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 ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 1933-690X
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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
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 humanprion 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
http://www.nature.com/ncomms/2014/141216/ncomms6821/full/ncomms6821.html
SUNDAY, JANUARY 19, 2025
ON THE ORIGIN OF TME AND BSE, WHAT IF?
https://transmissiblespongiformencephalopathy.blogspot.com/2025/01/on-origin-of-tme-and-bse-what-if.html
ON THE ORIGIN OF TME AND BSE, WHAT IF?
https://transmissiblespongiformencephalopathy.blogspot.com/2025/01/on-origin-of-tme-and-bse-what-if.html
SUNDAY, JANUARY 19, 2025
Scrapie Field Trial was developed at Mission, Texas, what if? Epidemiology of Scrapie in the United States
https://chronic-wasting-disease.blogspot.com/2025/01/scrapie-field-trial-was-developed-at.html
Scrapie Field Trial was developed at Mission, Texas, what if? Epidemiology of Scrapie in the United States
https://chronic-wasting-disease.blogspot.com/2025/01/scrapie-field-trial-was-developed-at.html
Terry S. Singeltary Sr.
