***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.***
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan.
*** This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada.
*** It also suggests a similar cause or source for atypical BSE in these countries. ***
Jianmin Yang 1 , Sandor Dudas 2 , Catherine Graham 2 , Markus Czub 3 , Tim McAllister 1 , Stefanie Czub 1 1 Agriculture and Agri-Food Canada Research Centre, Canada; 2 National and OIE BSE Reference Laboratory, Canada; 3 University of Calgary, Canada
Background: Three BSE types (classical and two atypical) have been identified on the basis of molecular characteristics of the misfolded protein associated with the disease. To date, each of these three types have been detected in Canadian cattle. Objectives: This study was conducted to further characterize the 16 Canadian BSE cases based on the biochemical properties of there associated PrPres.
Methods: Immuno-reactivity, molecular weight, glycoform profiles and relative proteinase K sensitivity of the PrPres from each of the 16 confirmed Canadian BSE cases was determined using modified Western blot analysis.
Results: Fourteen of the 16 Canadian BSE cases were C type, 1 was H type and 1 was L type. The Canadian H and L-type BSE cases exhibited size shifts and changes in glycosylation similar to other atypical BSE cases. PK digestion under mild and stringent conditions revealed a reduced protease resistance of the atypical cases compared to the C-type cases. N terminal-specific antibodies bound to PrPres from H type but not from C or L type. The C-terminal-specific antibodies resulted in a shift in the glycoform profile and detected a fourth band in the Canadian H-type BSE.
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. It also suggests a similar cause or source for atypical BSE in these countries.
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply;
***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE.
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
Posted by Terry S. Singeltary Sr. on 03 Jul 2015 at 16:53 GMT
P178 Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD
Dr Laura Pirisinu1, Dr Linh Tran2, Dr Gordon Mitchell3, Dr Aru Balachandran3, Dr Thierry Baron4, Dr Cristina Casalone5, Dr Michele Di Bari1, Dr Umberto Agrimi1. Dr Romolo Nonno1, Dr Sylvie Benestad2
1Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanita, Rome, Italy, 2Norwegian Veterinary Institute, Oslo, Norway, 3Canadian Food Inspection Agency, National and OlE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, Canada, 4Neurodeqenerative Diseases Unit, ANSES - French Agency for Food, Environmental and Occupational Health & Safety, Lyon, France, 5Istituto Zooprofilattico Sperimentale del Pietnonte, Liguria e Valle d'Aosta, Turin, Italy
Aims: In 2016, Chronic Wasting Disease (CWD) was detected for the first time in Europe in three wild Norwegian reindeer (Rangifer tarandus tarandus) and in two moose (Alces alces). The biochemical analysis and the immunohistochemical distribution of PrPSc from Norwegian reindeer revealed a pattern similar to North American (NA) isolates1. In this study, we studied the biochemical features of PrPSc from the two CWD cases in Norwegian moose.
Methods: Western blot (WB) analysis of PK-treated PrPSc (PrPres) from Norwegian moose and reindeer isolates was performed according to the ISS discriminatory WB protocol (used in BSE and scrapie Italian surveillance). PrPres fragments were determined by epitope mapping (SAF84, L42, 9A2, 12B2 mAbs), before and after deglycosylation. CWD isolates from Canadian cervids (wapiti, moose and white tailed deer) and a panel of small ruminant and bovine prion strains circulating in Europe were also analysed.
Results: WB analysis with different mAbs showed that PrPres from both Norwegian moose samples was different from that usually associated with CWD in cervids. Indeed, their main C-terminal fragment had a MW lower than the other CWD isolates, and could be discriminated by the absence of the 12B2 epitope. Furthermore, while NA CWD PrPSc is composed of a single PrPres fragment, Norwegian moose samples had an additional C-terminal PrPres fragment of ~13 kDa (CTF13). Among ovine TSEs, classical scrapie and Nor98 were discriminated from both Norwegian moose isolates, while CH1641 samples had molecular features partially overlapping with the moose, i.e. a low MW PrPres and the presence of CTF13. In contrast, moose PrPSc did not overlap with any bovine PrPSc. Indeed, the MW of moose PrPres was lower than H-BSE and similar to C-BSE and L-BSE PrPres, but the two bovine prions lacked additional PrPres fragments.
Conclusions: Unexpectedly, PrPSc from Norwegian moose revealed features substantially different from all other CWD isolates. The PrPSc pattern of Norwegian moose was also different from Canadian moose, suggesting that the variant PrPSc type observed does not simply reflect a host factor and could represent a new CWD strain. Furthermore, PrPSc of Norwegian moose can be easily discriminated from all BSE types, classical scrapie and Nor98, while showing significant overlapping only with CH1641. Bioassay in voles will help to clarify whether the different PrPSc types observed reflect the presence of a new CWD strain in Norwegian moose, and its relationships with known animal TSEs.
References: 1Benestad et al, Vet Res (2016}47:88
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
please see;
***Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
***Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
P-088 Transmission of experimental CH1641-like scrapie to bovine PrP overexpression mice
Kohtaro Miyazawa1, Kentaro Masujin1, Hiroyuki Okada1, Yuichi Matsuura1, Takashi Yokoyama2
1Influenza and Prion Disease Research Center, National Institute of Animal Health, NARO, Japan; 2Department of Planning and General Administration, National Institute of Animal Health, NARO
Introduction: Scrapie is a prion disease in sheep and goats. CH1641-lke scrapie is characterized by a lower molecular mass of the unglycosylated form of abnormal prion protein (PrpSc) compared to that of classical scrapie. It is worthy of attention because of the biochemical similarities of the Prpsc from CH1641-like and BSE affected sheep. We have reported that experimental CH1641-like scrapie is transmissible to bovine PrP overexpression (TgBoPrP) mice (Yokoyama et al. 2010). We report here the further details of this transmission study and compare the biological and biochemical properties to those of classical scrapie affected TgBoPrP mice.
Methods: The details of sheep brain homogenates used in this study are described in our previous report (Yokoyama et al. 2010). TgBoPrP mice were intracerebrally inoculated with a 10% brain homogenate of each scrapie strain. The brains of mice were subjected to histopathological and biochemical analyses.
Results: Prpsc banding pattern of CH1641-like scrapie affected TgBoPrP mice was similar to that of classical scrapie affected mice. Mean survival period of CH1641-like scrapie affected TgBoPrP mice was 170 days at the 3rd passage and it was significantly shorter than that of classical scrapie affected mice (439 days). Lesion profiles and Prpsc distributions in the brains also differed between CH1641-like and classical scrapie affected mice.
Conclusion: We succeeded in stable transmission of CH1641-like scrapie to TgBoPrP mice. Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
WS-02
Scrapie in swine: A diagnostic challenge
Justin J Greenlee1, Robert A Kunkle1, Jodi D Smith1, Heather W. Greenlee2
1National Animal Disease Center, US Dept. of Agriculture, Agricultural Research Service, United States; 2Iowa State University College of Veterinary Medicine
A naturally occurring prion disease has not been recognized in swine, but the agent of bovine spongiform encephalopathy does transmit to swine by experimental routes. Swine are thought to have a robust species barrier when exposed to the naturally occurring prion diseases of other species, but the susceptibility of swine to the agent of sheep scrapie has not been thoroughly tested.
Since swine can be fed rations containing ruminant derived components in the United States and many other countries, we conducted this experiment to test the susceptibility of swine to U.S. scrapie isolates by intracranial and oral inoculation. Scrapie inoculum was a pooled 10% (w/v) homogenate derived from the brains of clinically ill sheep from the 4th passage of a serial passage study of the U.S scrapie agent (No. 13-7) through susceptible sheep that were homozygous ARQ at prion protein residues 136, 154, and 171, respectively. Pigs were inoculated intracranially (n=19) with a single 0.75 ml dose or orally (n=24) with 15 ml repeated on 4 consecutive days. Necropsies were done on a subset of animals at approximately six months post inoculation (PI), at the time the pigs were expected to reach market weight. Remaining pigs were maintained and monitored for clinical signs of TSE until study termination at 80 months PI or when removed due to intercurrent disease (primarily lameness). Brain samples were examined by immunohistochemistry (IHC), western blot (WB), and enzyme-linked immunosorbent assay (ELISA). Brain tissue from a subset of pigs in each inoculation group was used for bioassay in mice expressing porcine PRNP.
At six-months PI, no evidence of scrapie infection was noted by any diagnostic method. However, at 51 months of incubation or greater, 5 animals were positive by one or more methods: IHC (n=4), WB (n=3), or ELISA (n=5). Interestingly, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study).
Swine inoculated with the agent of scrapie by the intracranial and oral routes do not accumulate abnormal prion protein (PrPSc) to a level detectable by IHC or WB by the time they reach typical market age and weight. However, strong support for the fact that swine are potential hosts for the agent of scrapie comes from positive bioassay from both intracranially and orally inoculated pigs and multiple diagnostic methods demonstrating abnormal prion protein in intracranially inoculated pigs with long incubation times.
Curriculum Vitae
Dr. Greenlee is Research Veterinary Medical Officer in the Virus and Prion Research Unit at the National Animal Disease Center, US Department of Agriculture, Agricultural Research Service. He applies his specialty in veterinary anatomic pathology to focused research on the intra- and interspecies transmission of prion diseases in livestock and the development of antemortem diagnostic assays for prion diseases. In addition, knockout and transgenic mouse models are used to complement ongoing experiments in livestock species. Dr. Greenlee has publications in a number of topic areas including prion agent decontamination, effects of PRNP genotype on susceptibility to the agent of sheep scrapie, characterization of US scrapie strains, transmission of chronic wasting disease to cervids and cattle, features of H-BSE associated with the E211 K polymorphism, and the development of retinal assessment for antemortem screening for prion diseases in sheep and cattle. Dr. Greenlee obtained his DVM degree and completed the PhD/residency program in Veterinary Pathology at Iowa State University. He is a Diplomate of the American College of Veterinary Pathologists.
Qingzhong Kong1,*, Mengjie Zheng1, Cristina Casalone2, Liuting Qing1,Shenghai Huang1,†, Bikram Chakraborty1, Ping Wang1, Fusong Chen1,Ignazio Cali1, Cristiano Corona2, Francesca Martucci2, Barbara Iulini2,Pierluigi Acutis2, Lan Wang1, Jingjing Liang1, Meiling Wang1, Xinyi Li1,Salvatore Monaco3, Gianluigi Zanusso3, Wen-Quan Zou1, Maria Caramelli2 andPierluigi Gambetti1,* +Author Affiliations
1Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106 2CEA, Istituto Zooprofilattico Sperimentale, 10154 Torino, Italy 3Department of Neurological and Visual Sciences, University of Verona, 37134 Verona, Italy Next Section ABSTRACT
Bovine spongiform encephalopathy (BSE), the prion disease in cattle, was widely believed to be caused by only one strain, BSE-C. BSE-C causes the fatal prion disease named new variant Creutzfeldt-Jacob disease in humans. Two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H, have been discovered in several countries since 2004; their transmissibility and phenotypes in humans are unknown. We investigated the infectivity and human phenotype of BASE strains by inoculating transgenic (Tg) mice expressing the human prion protein with brain homogenates from two BASE strain-infected cattle. Sixty percent of the inoculated Tg mice became infected after 20 to 22 months of incubation, a transmission rate higher than those reported for BSE-C. A quarter of BASE strain-infected Tg mice, but none of the Tg mice infected with prions causing a sporadic human prion disease, showed the presence of pathogenic prion protein isoforms in the spleen, indicating that the BASE prion is intrinsically lymphotropic. The pathological prion protein isoforms in BASE strain-infected humanized Tg mouse brains are different from those from the original cattle BASE or sporadic human prion disease. Minimal brain spongiosis and long incubation times are observed for the BASE strain-infected Tg mice.
***These results suggest that in humans, the BASE strain is a more virulent BSE strain and likely lymphotropic.
PPo2-26:
Transmission of Classical and Atypical (L-type) Bovine Spongiform Encephalopathy (BSE) Prions to Cynomolgus macaques
Fumiko Ono,1 Yoshio Yamakawa,2 Minoru Tobiume,3 Yuko Sato,3 Harutaka Katano,3 Kenichi Hagiwara,2 Iori Itagaki,1 Akio Hiyaoka,1 Katuhiko Komatuzaki,1 Yasunori Emoto,1 Hiroaki Shibata,4 Yuichi Murayama,5 Keiji Terao,4 Yasuhiro Yasutomi4 and Tetsutaro Sata3
1The Corporation for Production and Research of Laboratory Primates; Tsukuba City, Japan; 2Departments of Cell Biology and Biochemistry; and 3Pathology; National Institute of Infectious Diseases; Tokyo, Japan; 4Tsukuba Primate Research Center; National Institute of Biomedical Innovation; Tsukuba City, Japan; 5Prion Disease Research Team; National Institute of Animal Health; Tsukuba City, Japan
Key words: L-type BSE, cBSE, cynomolgus macaques, transmission
BSE prion derived from classical BSE (cBSE) or L-type BSE was characterized by inoculation into the brain of cynomolgus macaques. The neurologic manifestation was developed in all cynomolgus macaques at 27–43 months after intracerebral inoculation of brain homogenate from cBSE-affected cattle (BSE JP/6). Second transmission of cBSE from macaque to macaque shortened incubation period to 13–18 months. cBSE-affected macaques showed the similar clinical signs including hyperekplexia, tremor and paralysis in both primary and second transmission.
Two macaques were intracerebrally inoculated brain homogenate from the L-type BSE-affected cattle (BSE JP/24). The incubation periods were 19–20 months in primary transmission.
The clinical course of the L-type BSE-affected macaques differed from that in cBSE-affected macaques in the points of severe myoclonus without hyperekplexia.
The glycoform profile of PrPSc detected in macaque CNS was consistent with original pattern of either cBSE or L-typeBSE PrPSc, respectively.
Although severe spongiform change in the brain was remarkable in all BSE-affected macaques, severe spongiform spread widely in cerebral cortex in L-type BSE-affected macaques.
Heavy accumulation of PrPSc surrounded by vacuola formed florid plaques in cerebral cortex of cBSE-affected macaques.
Deposit of PrPSc in L-type BSE-affected macaque was weak and diffuse synaptic pattern in cerebrum, but large PrPSc plaques were evident at cerebellum.
MRI analysis, T2, T1, DW and flair sequences, at the time of autopsy revealed that brain atrophy and dilatation of cerebral ventricles were significantly severe in L-type BSE-affected macaques.
***These results suggest that L-type BSE is more virulent strain to primates comparing to cBSE.
Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate
Emmanuel E. Comoy1*, Cristina Casalone2, Nathalie Lescoutra-Etchegaray1, Gianluigi Zanusso3, Sophie Freire1, Dominique Marcé1, Frédéric Auvré1, Marie-Magdeleine Ruchoux1, Sergio Ferrari3, Salvatore Monaco3, Nicole Salès4, Maria Caramelli2, Philippe Leboulch1,5, Paul Brown1, Corinne I. Lasmézas4, Jean-Philippe Deslys1
1 Institute of Emerging Diseases and Innovative Therapies, CEA, Fontenay-aux-Roses, France, 2 Istituto Zooprofilattico Sperimentale del Piemonte, Turin, Italy, 3 Policlinico G.B. Rossi, Verona, Italy, 4 Scripps Florida, Jupiter, Florida, United States of America, 5 Genetics Division, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
Abstract Top Background Human variant Creutzfeldt-Jakob Disease (vCJD) results from foodborne transmission of prions from slaughtered cattle with classical Bovine Spongiform Encephalopathy (cBSE).
***Atypical forms of BSE, which remain mostly asymptomatic in aging cattle, were recently identified at slaughterhouses throughout Europe and North America, raising a question about human susceptibility to these new prion strains.
Methodology/Principal Findings Brain homogenates from cattle with classical BSE and atypical (BASE) infections were inoculated intracerebrally into cynomolgus monkeys (Macacca fascicularis), a non-human primate model previously demonstrated to be susceptible to the original strain of cBSE. The resulting diseases were compared in terms of clinical signs, histology and biochemistry of the abnormal prion protein (PrPres).
***The single monkey infected with BASE had a shorter survival, and a different clinical evolution, histopathology, and prion protein (PrPres) pattern than was observed for either classical BSE or vCJD-inoculated animals.
***Also, the biochemical signature of PrPres in the BASE-inoculated animal was found to have a higher proteinase K sensitivity of the octa-repeat region.
***We found the same biochemical signature in three of four human patients with sporadic CJD and an MM type 2 PrP genotype who lived in the same country as the infected bovine.
*** Conclusion/Significance Our results point to a possibly higher degree of pathogenicity of BASE than classical BSE in primates and also raise a question about a possible link to one uncommon subset of cases of apparently sporadic CJD.
***Thus, despite the waning epidemic of classical BSE, the occurrence of atypical strains should temper the urge to relax measures currently in place to protect public health from accidental contamination by BSE-contaminated products.
Citation: Comoy EE, Casalone C, Lescoutra-Etchegaray N, Zanusso G, Freire S, et al. (2008) Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate. PLoS ONE 3(8): e3017. doi:10.1371/journal.pone.0003017
Editor: Neil Mabbott, University of Edinburgh, United Kingdom
Received: April 24, 2008; Accepted: August 1, 2008; Published: August 20, 2008
Copyright: © 2008 Comoy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work has been supported by the Network of Excellence NeuroPrion.
Competing interests: CEA owns a patent covering the BSE diagnostic tests commercialized by the company Bio-Rad.
* E-mail: emmanuel.comoy@cea.fr
Session I - Prions: Structure, Strain and Detection (II)
Searching for BASE Strain Signature in Sporadic Creutzfedlt-Jakob Disease
Gianluigi Zanusso
Department of Neurological and Visual Sciences, Section of Clinical Neurology University of Verona, Verona, Italy.
Bovine amyloidotic spongiform encephalopathy (BASE) is a newly recognized form of bovine prion disease, which was originally detected in Italy in 2004 as an effect of active surveillance. BASE or BSE L-type (L is referred to the lower electrophoretic PrPSc migration than classical BSE) has now been reported in several countries, including Japan.
All field cases of BASE were older than 8 years and neurologically normal at the time of slaughtered. By experimental transmission, we defined the disease phenotype of cattle BASE, which is quite distinct from that seen in typical BSE and characterized by mental dullness and amyotrophy.
Surprisingly, following intraspecies and interspecies transmission the incubation period of BASE was shorter than BSE.
***The relatively easy transmission of BASE isolate as well as the molecular similarity with sporadic Creutzfeldt-Jakob disease (sCJD) have raised concern regarding its potential passage to humans. Tg humanized mice Met/Met at codon 129 challenged with both BSE and BASE isolates, showed a resistance to BSE but a susceptibility to BASE at a 60% rate; in addition, BASE-inoculated Cynomolgus (129 Met/Met) had shorter incubation periods than BSE-inoculated primates.
In this study we compared the biochemical properties of PrPSc in Cynomolgus and in TgHu Met/Met mice challenged with BSE and BASE strains, by conventional SDS-PAGE analysis and 2D separation. The results obtained disclose distinct conformational changes in PrPSc, which are dependent on the inoculated host but not on the codon 129 genotype.
This work was supported by Neuroprion contract n. FOOD CT 2004 -506579 (NOE)
P.150: Zoonotic potential of L-type BSE prions: A new prion disease in humans?
Emilie Jaumain,1 Stéphane Haïk,2 Isabelle Quadrio,3 Laetitia Herzog,1 Fabienne Reine,1 Armand Perret-Liaudet,3 Human Rezaei,1 Hubert Laude,1 Jean-Luc Vilotte,4 and Vincent Béringue1 1INR A (Institut National de la Recherche Agronomique); UR892; Virologie Immunologie Moléculaires; Jouy-en-Josas, France; 2IN SERM; Equipe maladie d’Alzheimer et maladies à Prions; CRicm; UMRS 1127; CNR S; UPMC. R.; ICM, Hôpital de la Salpêtrière; Paris, France; 3Neurobiologie, CMRR , Gériatrie, Hospices Civils de Lyon, Université Lyon 1-CNR S UMR5292-IN SERM U1028; Lyon, France; 3INR A; UMR1313; Génétique Animale et Biologie Intégrative; Jouy-en-Josas, France
Two novel prion strains, referred to as BSE-L and BSE-H, have been recognized in bovines through active prion surveillance programs, both being distinct from the epizootic, ‘classical’, BSE strain (C-BSE). Both H and L-types have been detected worldwide as rare cases occurring in aged animals. Like C-BSE prions, H- and L-types prions can propagate with relative ease in foreign species or in transgenic mouse lines expressing heterologous PrP sequences. A prion exhibiting biological properties similar to C-BSE agent sometimes emerged from these cross-species transmissions.
***Previously, L-type prions were shown to transmit to transgenic mice expressing human PrP with methionine at codon 129 with higher efficacy than C-BSE prions.
Here, we examined whether L-type prions propagate without any apparent transmission barrier in these mice and whether such ‘humanised’ L-type prions share biological properties with CJD prions.
L-type prions and a panel of human CJD cases with various genotypes at codon 129 and electrophoretic PrPres signatures were serially transmitted by intracerebral route to human PrP mice.
The biological phenotypes induced by these agents were compared by all the standard methods currently used to distinguish between prion strains.
***At each passage, L-type prions were also transmitted back to bovine PrP mice to assess whether the agent has evolved upon passaging on the human PrP sequence. L-type prions transmitted to human PrP mice at 100% attack rate, without notable alteration in the mean incubation times over 5 passages.
***At each passage, ‘humanized’ L-type prions were able to transmit back to bovine PrP transgenic mice without apparent transmission barrier, as based on the survival time and the restoration of a L-type BSE phenotype.
*** Comparison of mean incubation times on primary and subsequent passages in human PrP mice showed no overlap between L-type and sporadic CJD agents.
*** While the electrophoretic signature and regional distribution of PrPres in L-type diseased mouse brains resembled that seen after transmission of MM2 CJD strain type, both agents exhibited distinct resistance of the associated PrPres molecules to protease denaturation.
*** In summary, L-type prions can be passaged on the human PrP sequence without any obvious transmission barrier. The phenotype obtained differs from the classical CJD prion types known so far. Careful extrapolation would suggest that the zoonotic transmission of this agent could establish a new prion disease type in humans.
========Prion2013==========
The present data offer novel information on the tropism of the BASE agent and highlight relevant public health issues.
***While the transmission barrier for classical BSE is high in most species, BASE prions are readily transmissible to a variety of mammals including non-human primates [11]–[13], [35].
***Accordingly, the possibility of spreading of BASE prions through skeletal muscle to other species should be taken into account and evaluated in risk analysis studies.
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** 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. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
2014
***Moreover, L-BSE has been transmitted more easily to transgenic mice overexpressing a human PrP [13,14] or to primates [15,16] than C-BSE.
***It has been suggested that some sporadic CJD subtypes in humans may result from an exposure to the L-BSE agent.
*** Lending support to this hypothesis, pathological and biochemical similarities have been observed between L-BSE and an sCJD subtype (MV genotype at codon 129 of PRNP) [17], and between L-BSE infected non-human primate and another sCJD subtype (MM genotype) [15].
snip...
WEDNESDAY, MARCH 15, 2017
In vitro amplification of H-type atypical bovine spongiform encephalopathy by protein misfolding cyclic amplification
"When considering the atypical L-BSE and H-BSE diseases of cattle, they have been assessed in both non-human primate and transgenic mouse bioassays (with mice transgenic for human PRNP) and both model systems indicate that H-BSE and L-BSE may have increased zoonotic potential compare with C-BSE.
***The detection of all types of BSE is therefore of significant importance."
SUNDAY, JULY 23, 2017
Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy
*** Industry should be aware, however, of the implications of sporadic BSE. Its occurrence would necessitate the indefinite retention of all of the public health measures that exclude high-risk bovine tissues from the animal and human food chains, whereas its nonoccurrence would permit tissues that are now destroyed to be used as before, once orally acquired BSE has disappeared.
***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.***
Journal of Wildlife Diseases 50(3):660-665. 2014 https://doi.org/10.7589/2013-10-274
“Atypical” Chronic Wasting Disease in PRNP Genotype 225FF Mule Deer
Lisa L. Wolfe, Karen A. Fox, and Michael W. Miller Wildlife Disease Association 2014 Received: October 21, 2013; Accepted: January 22, 2014 [+] Author & Article Info
Abstract
We compared mule deer (Odocoileus hemionus) of two different PRNP genotypes (225SS, 225FF) for susceptibility to chronic wasting disease (CWD) in the face of environmental exposure to infectivity. All three 225SS deer had immunohistochemistry (IHC)-positive tonsil biopsies by 710 days postexposure (dpe), developed classic clinical signs by 723–1,200 dpe, and showed gross and microscopic pathology, enzyme-linked immunosorbent assay (ELISA) results, and IHC staining typical of prion disease in mule deer. In contrast, although all three 225FF deer also became infected, the two individuals surviving >720 dpe had consistently negative biopsies, developed more-subtle clinical signs of CWD, and died 924 or 1,783 dpe. The 225FF deer were “suspect” by ELISA postmortem but showed negative or equivocal IHC staining of lymphoid tissues; both clinically affected 225FF deer had spongiform encephalopathy in the absence of IHC staining in the brain tissue. The experimental cases resembled three cases encountered among five additional captive 225FF deer that were not part of our experiment but also died from CWD. Aside from differences in clinical disease presentation and detection, 225FF mule deer also showed other, more-subtle, atypical traits that may help to explain the rarity of this genotype in natural populations, even in the presence of enzootic CWD.
P35
ADAPTATION OF CHRONIC WASTING DISEASE (CWD) INTO HAMSTERS, EVIDENCE OF A WISCONSIN STRAIN OF CWD
Chad Johnson1, Judd Aiken2,3,4 and Debbie McKenzie4,5 1 Department of Comparative Biosciences, University of Wisconsin, Madison WI, USA 53706 2 Department of Agriculture, Food and Nutritional Sciences, 3 Alberta Veterinary Research Institute, 4.Center for Prions and Protein Folding Diseases, 5 Department of Biological Sciences, University of Alberta, Edmonton AB, Canada T6G 2P5 The identification and characterization of prion strains is increasingly important for the diagnosis and biological definition of these infectious pathogens. Although well-established in scrapie and, more recently, in BSE, comparatively little is known about the possibility of prion strains in chronic wasting disease (CWD), a disease affecting free ranging and captive cervids, primarily in North America. We have identified prion protein variants in the white-tailed deer population and demonstrated that Prnp genotype affects the susceptibility/disease progression of white-tailed deer to CWD agent. The existence of cervid prion protein variants raises the likelihood of distinct CWD strains. Small rodent models are a useful means of identifying prion strains. We intracerebrally inoculated hamsters with brain homogenates and phosphotungstate concentrated preparations from CWD positive hunter-harvested (Wisconsin CWD endemic area) and experimentally infected deer of known Prnp genotypes. These transmission studies resulted in clinical presentation in primary passage of concentrated CWD prions. Subclinical infection was established with the other primary passages based on the detection of PrPCWD in the brains of hamsters and the successful disease transmission upon second passage. Second and third passage data, when compared to transmission studies using different CWD inocula (Raymond et al., 2007) indicate that the CWD agent present in the Wisconsin white-tailed deer population is different than the strain(s) present in elk, mule-deer and white-tailed deer from the western United States endemic region.
FRIDAY, MAY 14, 2010
Prion Strain Mutation Determined by Prion Protein Conformational Compatibility and Primary Structure
MONDAY, JANUARY 09, 2017
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle
CDC Volume 23, Number 2—February 2017
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
Volume 23, Number 2—February 2017
Dispatch
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle
Abstract
To determine oral transmissibility of the L-type bovine spongiform encephalopathy (BSE) prion, we orally inoculated 16 calves with brain homogenates of the agent. Only 1 animal, given a high dose, showed signs and died at 88 months. These results suggest low risk for oral transmission of the L-BSE agent among cattle.
The epidemic of bovine spongiform encephalopathy (BSE) in cattle is thought to be caused by oral infection through consumption of feed containing the BSE agent (prion). Since 2003, different neuropathologic and molecular phenotypes of BSE have been identified as causing ≈110 cases of atypical BSE worldwide, mainly in aged cattle. Although the etiology and pathogenesis of atypical BSE are not yet fully understood, atypical BSE prions possibly cause sporadic cases of BSE (1).
The L-type BSE prion (L-BSE) has been experimentally transmitted to cattle by intracerebral challenge, and the incubation period was is shorter than that for classical BSE (C-BSE) prions (2–6). The origin of transmissible mink encephalopathy in ranch-raised mink is thought to be caused by ingestion of L-BSE–infected material (7). Although L-BSE has been orally transmitted to mouse lemurs (8), it remains to be established whether L-BSE can be transmitted to cattle by oral infection. We therefore investigated the transmissibility of L-BSE by the oral route and tissue distribution of disease-associated prion protein (PrPSc) in cattle. All experiments involving animals were performed with the approval of the Animal Ethical Committee and the Animal Care and Use Committee of the National Institute of Animal Health (approval nos. 07–88 and 08–010).
The Study
We divided a group of 16 Holstein female calves, 3–5 months of age, into 4 groups of 2–6 animals each. Each group of calves was orally administered 1 g (n = 4), 5 g (n = 6), 10 g (n = 4), or 50 g (n = 2) of pooled whole-brain homogenate prepared from cattle experimentally infected with L-BSE (3,6) (Table(https://wwwnc.cdc.gov/eid/article/23/2/16-1416-t1)). The endpoint titer of the pooled brain homogenate assayed in bovinized transgenic (TgBoPrP) mice was 106.9 of 50% lethal dose/g tissue (data not shown). As noninfected controls, 3 female calves were obtained at 3–4 months of age and euthanized at 60, 92, and 103 months of age, and samples were analyzed as for the experimental animals.
At 88 months after inoculation, 1 of the animals (91 months of age) that had received 50 g of L-BSE–infected brain homogenate was unable to get up. The animal extended her forelimbs and hind limbs rigidly forward but did not show persistent knuckling of her fetlock; she did not have difficulty eating and drinking. Seven days after appearance of clinical signs, the animal was found dead, having shown no characteristic signs of L-BSE, such as dullness, lowering of the head, and overreactivity to external stimuli, which had previously been observed after intracerebral inoculation of animals under experimental conditions (4).
Histopathologic examination of tissues from this animal revealed minimal or mild spongiform changes of the gray matter neuropil in the thalamic and brainstem nuclei; however, these changes were not visible in the cerebral and cerebellar cortices, the olfactory bulb, or the dorsal motor nucleus of the vagus nerve at the obex. Higher amounts of proteinase K–resistant PrPSc, analyzed by Western blotting with monoclonal antibody T2 (9), were detected in the thalamus, brainstem, cerebellum, spinal cord, and retina (Figure 1, lanes 8–16; Figures 2, panels A, B), whereas PrPSc accumulation was lower in the cerebral cortices and the olfactory bulb (Figure 1, lanes 1–6). The molecular characteristics of proteinase K–resistant PrPSc, such as the molecular weight and the glycoform profile in the brain of the animal, were identical to those observed in the inoculum. The most conspicuous PrPSc finding, obtained by using immunohistochemistry with monoclonal antibody F99/97.6.1 (VMRD, Pullman, WA, USA), was fine and coarse granular deposits in the neuropil of the thalamus, brainstem, and gray matter of the spinal cord, and in the retina. Perineuronal PrPSc staining was conspicuous in the large neurons of the thalamic and brainstem nuclei (Figure 2, panel C) but less common in other brain areas. Fewer PrPSc deposits were dispersed in the dorsal motor nucleus of the vagus nerve at the obex (Figure 2, panel A). No amyloid plaques were detectable in any brain section. In the extracerebral tissues, PrPSc was lower in most of the samples from the nerve ganglia (trigeminal, dorsal root, stellate, cervical cranial, nodose, and celiac and mesenteric), cauda equina, vagal nerve, optic nerve, neurohypophysis, ocular muscle, and adrenal medulla (Figure 1, lanes 17–33; Figures 2, panels D–H). However, no PrPSc signal was detected in most of the somatic nerve fibers (Figure 1, lanes 25, 26, 29, 30), the enteric nervous system (Figure 1, lanes 32, 33), and any lymphoid organs including the remaining Peyer’s patches (data not shown).
The only other animal inoculated with 50 g of L-BSE brain material was alive and clinically healthy as of postinoculation month 94 (December 2016). Calves that received 1 g, 5 g, or 10 g of L-BSE brain tissues showed no clinical signs of BSE and were euthanized and underwent necropsy 51–86 months after inoculation (Table(https://wwwnc.cdc.gov/eid/article/23/2/16-1416-t1)). For all of these animals and the uninfected controls, PrPSc results were negative by Western blot and immunohistochemical analysis.
Conclusions
Our results suggest that the risk for oral transmission of L-BSE among cattle may be very low; after 88 months, the only case of transmission occurred in a cow that had been inoculated with a high dose of L-BSE–infected brain homogenate. The incubation period was much longer for cattle dosed orally with L-BSE–infected brain homogenate than for cattle dosed orally with C-BSE–infected tissue (34−74 mo for C-BSE) (10). This finding may suggest that the L-BSE prion requires much longer to propagate from the gut to the central nervous system. In addition, the lack of clinical signs, except for difficulty in rising, may present a genuine clinical picture of L-BSE under natural conditions (11). In most cases of naturally occurring atypical BSE identified so far, the animals were >8 years of age, except for 3 cases: 1 H-BSE and 1 L-BSE in Spain (1) and 1 H-BSE in Germany (12). Therefore, we cannot exclude the possibility that L-BSE developed sporadically/spontaneously. However, this case may not have naturally occurred, in view of the low prevalence of L-BSE in Japan during October 2001–August 2016, which was 0.065 cases/1 million tested adult animals. In our study, the remaining live animal, challenged with 50 g of L-BSE brain homogenate, will provide the further information about the oral transmissibility to cattle. Bioassays of brain samples in TgBoPrP mice are ongoing.
The neuroanatomical PrPSc distribution pattern of orally challenged cattle differed somewhat from that described in cattle naturally and intracerebrally challenged with L-BSE (2–6,11,13,14), The conspicuous differences between the case we report and cases of natural and experimental infection are 1) higher amounts of PrPSc in the caudal medulla oblongata and the spinal cord coupled with that in the thalamus and the more rostral brainstem and 2) relatively low amounts of PrPSc in the cerebral cortices and the olfactory bulb. Furthermore, fewer PrPSc deposits in the dorsal motor nucleus of the vagus nerve may indicate that the parasympathetic retrogressive neuroinvasion pathway does not contribute to transport of the L-BSE prion from the gut to the brain, which is in contrast to the vagus-associated transport of the agent in C-BSE (15). PrPSc accumulation in the extracerebral tissues may be a result of centrifugal trafficking of the L-BSE prion from the central nervous system along somatic or autonomic nerve fibers rather than centripetal propagation of the agent (4,6,9). Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
Dr. Okada is a veterinary pathologist and chief researcher at the National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan. His research focuses on the pathogenesis of animal prion diseases in ruminants as natural hosts and in experimentally infected animals.
Acknowledgments
We thank Naoko Tabeta, Naomi Furuya, Junko Yamada, Ritsuko Miwa, Noriko Shinozaki, and the animal caretakers for their expert technical assistance.
This work was supported by grants-in-aid from the BSE and Other Prion Disease project and the Improving Food Safety and Animal Health project of the Ministry of Agriculture, Forestry and Fisheries, Japan.
References
***********OCTOBER 2015*************
*** PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS ***
THANK YOU PRION 2015 TAYLOR & FRANCIS, Professor Chernoff, and Professor Aguzzi et al, for making these PRION 2015 Congressional Poster and Oral Abstracts available freely to the public. ...Terry S. Singeltary Sr.
P.108: Successful oral challenge of adult cattle with classical BSE
Sandor Dudas1,*, Kristina Santiago-Mateo1, Tammy Pickles1, Catherine Graham2, and Stefanie Czub1 1Canadian Food Inspection Agency; NCAD Lethbridge; Lethbridge, Alberta, Canada; 2Nova Scotia Department of Agriculture; Pathology Laboratory; Truro, Nova Scotia, Canada
Classical Bovine spongiform encephalopathy (C-type BSE) is a feed- and food-borne fatal neurological disease which can be orally transmitted to cattle and humans. Due to the presence of contaminated milk replacer, it is generally assumed that cattle become infected early in life as calves and then succumb to disease as adults. Here we challenged three 14 months old cattle per-orally with 100 grams of C-type BSE brain to investigate age-related susceptibility or resistance. During incubation, the animals were sampled monthly for blood and feces and subjected to standardized testing to identify changes related to neurological disease. At 53 months post exposure, progressive signs of central nervous system disease were observed in these 3 animals, and they were euthanized. Two of the C-BSE animals tested strongly positive using standard BSE rapid tests, however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE. Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
***Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE.
We are further examining explanations for the unusual disease presentation in the third challenged animal.
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama National Institute of Animal Health; Tsukuba, Japan
To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplifi- cation (PMCA).
Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.
Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
***P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
Sandor Dudas, John G Gray, Renee Clark, and Stefanie Czub Canadian Food Inspection Agency; Lethbridge, AB Canada
Keywords: Atypical BSE, oral transmission, RT-QuIC
The detection of bovine spongiform encephalopathy (BSE) has had a significant negative impact on the cattle industry worldwide. In response, governments took actions to prevent transmission and additional threats to animal health and food safety. While these measures seem to be effective for controlling classical BSE, the more recently discovered atypical BSE has presented a new challenge. To generate data for risk assessment and control measures, we have challenged cattle orally with atypical BSE to determine transmissibility and mis-folded prion (PrPSc) tissue distribution. Upon presentation of clinical symptoms, animals were euthanized and tested for characteristic histopathological changes as well as PrPSc deposition.
The H-type challenged animal displayed vacuolation exclusively in rostral brain areas but the L-type challenged animal showed no evidence thereof. To our surprise, neither of the animals euthanized, which were displaying clinical signs indicative of BSE, showed conclusive mis-folded prion accumulation in the brain or gut using standard molecular or immunohistochemical assays. To confirm presence or absence of prion infectivity, we employed an optimized real-time quaking induced conversion (RT-QuIC) assay developed at the Rocky Mountain Laboratory, Hamilton, USA.
Detection of PrPSc was unsuccessful for brain samples tests from the orally inoculated L type animal using the RT-QuIC. It is possible that these negative results were related to the tissue sampling locations or that type specific optimization is needed to detect PrPSc in this animal. We were however able to consistently detect the presence of mis-folded prions in the brain of the H-type inoculated animal. Considering the negative and inconclusive results with other PrPSc detection methods, positive results using the optimized RT-QuIC suggests the method is extremely sensitive for H-type BSE detection. This may be evidence of the first successful oral transmission of H type atypical BSE in cattle and additional investigation of samples from these animals are ongoing.
Additional BSE TSE prion testing detects pathologic lesion in unusual brain location and PrPsc by PMCA only, how many cases have we missed?
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