Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie

AbstractPigs are susceptible to infection with the classical bovine spongiform encephalopathy (C-BSE) agent following experimental inoculation, and PrPSc accumulation was detected in porcine tissues after the inoculation of certain scrapie and chronic wasting disease isolates. However, a robust transmission barrier has been described in this species and, although they were exposed to C-BSE agent in many European countries, no cases of natural transmissible spongiform encephalopathies (TSE) infections have been reported in pigs. Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions. Here, we conducted a study to determine if pigs are susceptible to atypical scrapie. To this end, 12, 8–9-month-old minipigs were intracerebrally inoculated with two atypical scrapie sources. Animals were euthanized between 22- and 72-months post inoculation without clinical signs of TSE. All pigs tested negative for PrPSc accumulation by enzyme immunoassay, immunohistochemistry, western blotting and bioassay in porcine PrP mice. Surprisingly, in vitro protein misfolding cyclic amplification demonstrated the presence of C-BSE prions in different brain areas from seven pigs inoculated with both atypical scrapie isolates. Our results suggest that pigs exposed to atypical scrapie prions could become a reservoir for C-BSE and corroborate that C-BSE prions emerge during interspecies passage of atypical scrapie.

Download Full-text

Susceptibility of Cattle to First-passage Intracerebral Inoculation with Chronic Wasting Disease Agent from White-tailed Deer

Veterinary Pathology ◽

10.1354/vp.44-4-487 ◽

2007 ◽

Vol 44 (4) ◽

pp. 487-493 ◽

Cited By ~ 43

Author(s):

A. N. Hamir ◽

J. M. Miller ◽

R. A. Kunkle ◽

S. M. Hall ◽

J. A. Richt

Keyword(s):

Chronic Wasting Disease ◽

Prion Diseases ◽

Clinical Signs ◽

Diagnostic Techniques ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Wasting Disease ◽

Spongiform Encephalopathies ◽

Disease Agent ◽

Sheep Scrapie

Fourteen, 3-month-old calves were intracerebrally inoculated with the agent of chronic wasting disease (CWD) from white-tailed deer (CWDwtd) to compare the clinical signs and neuropathologic findings with those of certain other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie, CWD of mule deer [CWDmd], bovine spongiform encephalopathy [BSE], and transmissible mink encephalopathy). Two uninoculated calves served as controls. Within 26 months postinoculation (MPI), 12 inoculated calves had lost considerable weight and eventually became recumbent. Of the 12 inoculated calves, 11 (92%) developed clinical signs. Although spongiform encephalopathy (SE) was not observed, abnormal prion protein (PrPd) was detected by immunohistochemistry (IHC) and Western blot (WB) in central nervous system tissues. The absence of SE with presence of PrPd has also been observed when other TSE agents (scrapie and CWDmd) were similarly inoculated into cattle. The IHC and WB findings suggest that the diagnostic techniques currently used to confirm BSE would detect CWDwtd in cattle, should it occur naturally. Also, the absence of SE and a distinctive IHC pattern of CWDwtd and CWDmd in cattle suggests that it should be possible to distinguish these conditions from other TSEs that have been experimentally transmitted to cattle.

Download Full-text

Effect of Scrapie Prion Infection in Ovine Bone Marrow-Derived Mesenchymal Stem Cells and Ovine Mesenchymal Stem Cell-Derived Neurons

Animals ◽

10.3390/ani11041137 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1137

Author(s):

Laura García-Mendívil ◽

Diego R. Mediano ◽

Adelaida Hernaiz ◽

David Sanz-Rubio ◽

Francisco J. Vázquez ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Cellular Prion Protein ◽

Transmissible Spongiform Encephalopathies ◽

Post Inoculation ◽

Spongiform Encephalopathies ◽

Prion Infection ◽

Over Time

Scrapie is a prion disease affecting sheep and goats and it is considered a prototype of transmissible spongiform encephalopathies (TSEs). Mesenchymal stem cells (MSCs) have been proposed as candidates for developing in vitro models of prion diseases. Murine MSCs are able to propagate prions after previous mouse-adaptation of prion strains and, although ovine MSCs express the cellular prion protein (PrPC), their susceptibility to prion infection has never been investigated. Here, we analyze the potential of ovine bone marrow-derived MSCs (oBM-MSCs), in growth and neurogenic conditions, to be infected by natural scrapie and propagate prion particles (PrPSc) in vitro, as well as the effect of this infection on cell viability and proliferation. Cultures were kept for 48–72 h in contact with homogenates of central nervous system (CNS) samples from scrapie or control sheep. In growth conditions, oBM-MSCs initially maintained detectable levels of PrPSc post-inoculation, as determined by Western blotting and ELISA. However, the PrPSc signal weakened and was lost over time. oBM-MSCs infected with scrapie displayed lower cell doubling and higher doubling times than those infected with control inocula. On the other hand, in neurogenic conditions, oBM-MSCs not only maintained detectable levels of PrPSc post-inoculation, as determined by ELISA, but this PrPSc signal also increased progressively over time. Finally, inoculation with CNS extracts seems to induce the proliferation of oBM-MSCs in both growth and neurogenic conditions. Our results suggest that oBM-MSCs respond to prion infection by decreasing their proliferation capacity and thus might not be permissive to prion replication, whereas ovine MSC-derived neuron-like cells seem to maintain and replicate PrPSc.

Download Full-text

Detection of Pathognomonic Biomarker PrPSc and the Contribution of Cell Free-Amplification Techniques to the Diagnosis of Prion Diseases

Biomolecules ◽

10.3390/biom10030469 ◽

2020 ◽

Vol 10 (3) ◽

pp. 469

Author(s):

Hasier Eraña ◽

Jorge M. Charco ◽

Ezequiel González-Miranda ◽

Sandra García-Martínez ◽

Rafael López-Moreno ◽

...

Keyword(s):

Neurodegenerative Diseases ◽

Protein Misfolding ◽

Prion Diseases ◽

Immunohistochemical Analysis ◽

Body Fluids ◽

Detection Methods ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathies ◽

Prion Propagation

Transmissible spongiform encephalopathies or prion diseases are rapidly progressive neurodegenerative diseases, the clinical manifestation of which can resemble other promptly evolving neurological maladies. Therefore, the unequivocal ante-mortem diagnosis is highly challenging and was only possible by histopathological and immunohistochemical analysis of the brain at necropsy. Although surrogate biomarkers of neurological damage have become invaluable to complement clinical data and provide more accurate diagnostics at early stages, other neurodegenerative diseases show similar alterations hindering the differential diagnosis. To solve that, the detection of the pathognomonic biomarker of disease, PrPSc, the aberrantly folded isoform of the prion protein, could be used. However, the amounts in easily accessible tissues or body fluids at pre-clinical or early clinical stages are extremely low for the standard detection methods. The solution comes from the recent development of in vitro prion propagation techniques, such as Protein Misfolding Cyclic Amplification (PMCA) and Real Time-Quaking Induced Conversion (RT-QuIC), which have been already applied to detect minute amounts of PrPSc in different matrixes and make early diagnosis of prion diseases feasible in a near future. Herein, the most relevant tissues and body fluids in which PrPSc has been detected in animals and humans are being reviewed, especially those in which cell-free prion propagation systems have been used with diagnostic purposes.

Download Full-text

Chronic wasting disease and atypical forms of bovine spongiform encephalopathy and scrapie are not transmissible to mice expressing wild-type levels of human prion protein

Journal of General Virology ◽

10.1099/vir.0.042507-0 ◽

2012 ◽

Vol 93 (7) ◽

pp. 1624-1629 ◽

Cited By ~ 52

Author(s):

Rona Wilson ◽

Chris Plinston ◽

Nora Hunter ◽

Cristina Casalone ◽

Cristiano Corona ◽

...

Keyword(s):

Bovine Spongiform Encephalopathy ◽

Prion Protein ◽

Chronic Wasting Disease ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Wild Type ◽

Wasting Disease ◽

Spongiform Encephalopathies ◽

Jakob Disease ◽

Human Prion Protein

The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt–Jakob disease (vCJD) has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several novel TSEs in sheep, cattle and deer have been described and the risk posed to humans by these agents is currently unknown. In this study, we inoculated two forms of atypical BSE (BASE and H-type BSE), a chronic wasting disease (CWD) isolate and seven isolates of atypical scrapie into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP). Upon challenge with these ruminant TSEs, gene-targeted Tg mice expressing human PrP did not show any signs of disease pathology. These data strongly suggest the presence of a substantial transmission barrier between these recently identified ruminant TSEs and humans.

Download Full-text

Spiroplasma spp. from transmissible spongiform encephalopathy brains or ticks induce spongiform encephalopathy in ruminants

Journal of Medical Microbiology ◽

10.1099/jmm.0.47159-0 ◽

2007 ◽

Vol 56 (9) ◽

pp. 1235-1242 ◽

Cited By ~ 33

Author(s):

Frank O. Bastian ◽

Dearl E. Sanders ◽

Will A. Forbes ◽

Sue D. Hagius ◽

Joel V. Walker ◽

...

Keyword(s):

Transmissible Spongiform Encephalopathy ◽

Clinical Signs ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Dependent Manner ◽

Spongiform Encephalopathies ◽

Sheep And Goats ◽

Natural Hosts ◽

Serological Studies ◽

Sheep Brain

Spiroplasma, small motile wall-less bacteria, are linked by molecular and serological studies to the transmissible spongiform encephalopathies (TSEs), which include scrapie in sheep, chronic wasting disease (CWD) in deer and Creutzfeldt–Jakob disease in humans. In this study, two experiments were undertaken to determine the role of spiroplasma in the pathogenesis of TSE. In experiment 1, Spiroplasma mirum, a rabbit tick isolate that had previously been shown to experimentally induce spongiform encephalopathy in rodents, was inoculated intracranially (IC) into ruminants. S. mirum-inoculated deer manifested clinical signs of TSE after 1.5 to 5.5 months incubation. The deer, as well as sheep and goats, inoculated with S. mirum developed spongiform encephalopathy in a dose-dependent manner. In experiment 2, spiroplasma closely related to S. mirum were isolated from TSE-affected brains via passage in embryonated eggs, and propagated in cell-free M1D media. Spiroplasma spp. isolates from scrapie-affected sheep brain and from CWD-affected deer brain inoculated IC into sheep and goats induced spongiform encephalopathy closely resembling natural TSE in these animals. These data show spiroplasma to be consistently associated with TSE, and able experimentally to cause TSE in ruminant animal models, therein questioning the validity of studies that have concluded the prion, a miss-folded protease-resistant protein that builds up in TSE brains during the course of the disease, to be the sole causal agent. The spiroplasma infection models reported here will be important for investigating factors involved in the pathogenesis of TSE since ruminants are the natural hosts.

Download Full-text

Prion protein as a target for therapeutic interventions

Pure and Applied Chemistry ◽

10.1351/pac200476050915 ◽

2004 ◽

Vol 76 (5) ◽

pp. 915-920 ◽

Cited By ~ 4

Author(s):

P. P. Liberski

Keyword(s):

Prion Protein ◽

Phenotypic Expression ◽

Therapeutic Interventions ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Public Health Perspective ◽

Spongiform Encephalopathies ◽

Mad Cow Disease

Transmissible spongiform encephalopathies (TSEs), currently known as prion diseases, are neurodegenerative disorders of the central nervous system (CNS) caused by an elusive infectious agent called “prion” (proteinaceous infectious particle). These dis orders include: kuru, Creutzfeldt –Jakob disease (CJD) and its variant (vCJD), Gerstmann–Sträussler–Scheinker (GSS) disease and fatal familial insomnia (FFI) in humans, scrapie in sheep and goats, bovine spongiform encephalopathy (BSE) or mad cow disease, and chronic wasting disease (CWD) in cervids. According to the widely accepted “prion hypothesis”, prion is an aggregate of the abnormal isoform of prion protein (PrPSc). Prion protein is a cell-derived glycoprotein (this normal isoform is called PrPc) encoded by a gene on chromosome 20 in humans (PRNP). In familial forms of TSEs, mutations within the ORF of PRNP are linked to the phenotypic expression of the disease. TSEs are important from public health perspective, and “mad cow disease has created the greatest threat to the safety of human food supply in modern times. vCJD threatens the safety of the blood supply worldwide”. Thus, to search for effective therapy is more than an urgent task. In TSEs, aggregates of PrPSc accumulate in the brain in a form of plaques, or synaptic deposits. The conversion of PrPc into PrPSc and subsequent deposits of PrPSc are targets for therapeutic interventions. These include: tricyclic compounds—acridine and phenothiazine derivatives; quinacrine; anti-PrPSc antibodies; dendrimers; polyethylene antibiotics (amphotericin B, MS-8209); pentosan polysulfate; and dextran sulfate. All these compounds are active in many in vitro and in vivo assays, but not proved definitely active in humans. Thus, albeit interesting and promising, the chemotherapy of TSEs is still in the infant phase.

Download Full-text

Autonomous Nervous System with Respect to Dressing of Cattle Carcasses and Its Probable Role in Transfer of PrPres Molecules

Journal of Food Protection ◽

10.4315/0362-028x-66.5.890 ◽

2003 ◽

Vol 66 (5) ◽

pp. 890-895 ◽

Cited By ~ 3

Author(s):

R. FRIES ◽

T. EGGERS ◽

G. HILDEBRANDT ◽

K. RAUSCHER ◽

S. BUDA ◽

...

Keyword(s):

Nervous System ◽

Vagus Nerve ◽

Animal Feed ◽

Stellate Ganglion ◽

Clinical Signs ◽

Transmissible Spongiform Encephalopathies ◽

Autonomous Nervous System ◽

Spongiform Encephalopathy ◽

Thoracic Vertebrae ◽

Spongiform Encephalopathies

Pathogen prions are widely recognized as the causative agent in bovine spongiform encephalopathy (BSE) and other transmissible spongiform encephalopathies. However, more research on the possible transmission routes of this agent once it has reached the host is needed. There is evidence based on the anatomy and physiology of the autonomous nervous system (ANS), as well as observations for different animal species, that the ANS might be involved in the axonal drainage of pathogen prions toward the central nervous system. In this context, more attention should be paid to the cranial cervical ganglion, the stellate ganglion, the chain of paravertebral ganglia next to the first six thoracic vertebrae, the chain of the paravertebralganglia next to loin vertebrae 1 through 6, the vagus nerve in the neck region and in the mediastine, and the esophagus (because of its close connection to the vagus nerve). For a more detailed risk analysis with respect to these tissues, the ANSs of animals having shown clinical signs of BSE might be examined to corroborate the evidence presented here. In the meantime, as a precautionary measure, the tissue addressed should be taken out of the human food chain, taken out of animal feed, and handled as if it were specified risk material. It is technically possible to remove these parts during cutting and dressing.

Download Full-text

Neuropathology of Animal Prion Diseases

Biomolecules ◽

10.3390/biom11030466 ◽

2021 ◽

Vol 11 (3) ◽

pp. 466

Author(s):

Leonor Orge ◽

Carla Lima ◽

Carla Machado ◽

Paula Tavares ◽

Paula Mendonça ◽

...

Keyword(s):

Prion Diseases ◽

Clinical Signs ◽

Small Ruminants ◽

Neuronal Loss ◽

Cellular Prion Protein ◽

Brain Inflammation ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Spongiform Encephalopathies ◽

Lesion Profile

Transmissible Spongiform Encephalopathies (TSEs) or prion diseases are a fatal group of infectious, inherited and spontaneous neurodegenerative diseases affecting human and animals. They are caused by the conversion of cellular prion protein (PrPC) into a misfolded pathological isoform (PrPSc or prion- proteinaceous infectious particle) that self-propagates by conformational conversion of PrPC. Yet by an unknown mechanism, PrPC can fold into different PrPSc conformers that may result in different prion strains that display specific disease phenotype (incubation time, clinical signs and lesion profile). Although the pathways for neurodegeneration as well as the involvement of brain inflammation in these diseases are not well understood, the spongiform changes, neuronal loss, gliosis and accumulation of PrPSc are the characteristic neuropathological lesions. Scrapie affecting small ruminants was the first identified TSE and has been considered the archetype of prion diseases, though atypical and new animal prion diseases continue to emerge highlighting the importance to investigate the lesion profile in naturally affected animals. In this report, we review the neuropathology and the neuroinflammation of animal prion diseases in natural hosts from scrapie, going through the zoonotic bovine spongiform encephalopathy (BSE), the chronic wasting disease (CWD) to the newly identified camel prion disease (CPD).

Download Full-text

Generation of human chronic wasting disease in transgenic mice

Acta Neuropathologica Communications ◽

10.1186/s40478-021-01262-y ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Zerui Wang ◽

Kefeng Qin ◽

Manuel V. Camacho ◽

Ignazio Cali ◽

Jue Yuan ◽

...

Keyword(s):

Transgenic Mice ◽

Prion Disease ◽

Protein Misfolding ◽

Chronic Wasting Disease ◽

Cellular Prion Protein ◽

Spongiform Encephalopathy ◽

Species Barrier ◽

Wasting Disease ◽

Bona Fide

AbstractChronic wasting disease (CWD) is a cervid prion disease caused by the accumulation of an infectious misfolded conformer (PrPSc) of cellular prion protein (PrPC). It has been spreading rapidly in North America and also found in Asia and Europe. Although bovine spongiform encephalopathy (i.e. mad cow disease) is the only animal prion disease known to be zoonotic, the transmissibility of CWD to humans remains uncertain. Here we report the generation of the first CWD-derived infectious human PrPSc by elk CWD PrPSc-seeded conversion of PrPC in normal human brain homogenates using in vitro protein misfolding cyclic amplification (PMCA). Western blotting with human PrP selective antibody confirmed that the PMCA-generated protease-resistant PrPSc was derived from the human PrPC substrate. Two lines of humanized transgenic mice expressing human PrP with either Val or Met at the polymorphic codon 129 developed clinical prion disease following intracerebral inoculation with the PMCA-generated CWD-derived human PrPSc. Diseased mice exhibited distinct PrPSc patterns and neuropathological changes in the brain. Our study, using PMCA and animal bioassays, provides the first evidence that CWD PrPSc can cross the species barrier to convert human PrPC into infectious PrPSc that can produce bona fide prion disease when inoculated into humanized transgenic mice.

Download Full-text

Prion Strain- and Species-Dependent Effects of Antiprion Molecules in Primary Neuronal Cultures

Journal of Virology ◽

10.1128/jvi.01502-07 ◽

2007 ◽

Vol 81 (24) ◽

pp. 13794-13800 ◽

Cited By ~ 41

Author(s):

Sabrina Cronier ◽

Vincent Beringue ◽

Anne Bellon ◽

Jean-Michel Peyrin ◽

Hubert Laude

Keyword(s):

Transmissible Spongiform Encephalopathy ◽

Cell System ◽

Transmissible Spongiform Encephalopathies ◽

Spongiform Encephalopathy ◽

Neuronal Cultures ◽

Primary Neuronal Cultures ◽

Spongiform Encephalopathies ◽

The Central Nervous System

ABSTRACT Transmissible spongiform encephalopathies (TSE) arise as a consequence of infection of the central nervous system by prions and are incurable. To date, most antiprion compounds identified by in vitro screening failed to exhibit therapeutic activity in animals, thus calling for new assays that could more accurately predict their in vivo potency. Primary nerve cell cultures are routinely used to assess neurotoxicity of chemical compounds. Here, we report that prion strains from different species can propagate in primary neuronal cultures derived from transgenic mouse lines overexpressing ovine, murine, hamster, or human prion protein. Using this newly developed cell system, the activity of three generic compounds known to cure prion-infected cell lines was evaluated. We show that the antiprion activity observed in neuronal cultures is species or strain dependent and recapitulates to some extent the activity reported in vivo in rodent models. Therefore, infected primary neuronal cultures may be a relevant system in which to investigate the efficacy and mode of action of antiprion drugs, including toward human transmissible spongiform encephalopathy agents.

Download Full-text