scholarly journals Preclinical Diagnosis of Scrapie by Immunohistochemistry of Third Eyelid Lymphoid Tissue

2000 ◽  
Vol 38 (9) ◽  
pp. 3254-3259 ◽  
Author(s):  
K. I. O'Rourke ◽  
T. V. Baszler ◽  
T. E. Besser ◽  
J. M. Miller ◽  
R. C. Cutlip ◽  
...  
Keyword(s):  
Lymphoid Tissue ◽  
Mammalian Species ◽  
Clinical Disease ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Animal Testing ◽  
Live Animal ◽  
Spongiform Encephalopathies ◽  
Clinically Normal ◽  
Neurologic Disorders

Ovine scrapie is a member of the transmissible spongiform encephalopathies (TSEs), a heterogeneous family of fatal neurologic disorders characterized by deposition of an abnormal isoform (prion protein [PrP] PrP-Sc) of a cellular sialoglycoprotein in neural tissue. PrP-Sc is detectable in some lymphoid tissues of infected sheep months or years before development of clinical disease. Detection of PrP-Sc in these tissues is the basis for live-animal testing. In this study, we characterize the performance of a preclinical diagnostic test for ovine scrapie based on a monoclonal antibody (MAb)-based immunohistochemistry assay of nictitating membrane (“third eyelid”)-associated lymphoid tissue. The results of third eyelid immunohistochemistry assay agreed with the scrapie status of the sheep for 41 of 42 clinical suspects with confirmed scrapie and 174 of 175 sheep without scrapie. Third eyelid sampling agreed with the scrapie status for 36 of 41 clinically normal sheep positive for PrP-Sc immunostaining of brain tissue, including 27 sheep with positive biopsy specimens that progressed to clinical disease with confirmed scrapie 3 to 20 months after biopsy. The assay used MAb F89/160.1.5, which binds to residues 142 to 145 of ovine PrP. This antibody can be used in combination with MAb F99/97.6.1, which binds to residues 220 to 225. One or both MAbs in this cocktail recognize PrP sequences conserved in most mammalian species in which natural TSEs have been reported. Immunohistochemistry assay of routinely formalin-fixed lymphoid tissues with a cocktail of pan-specific MAbs is a practical, readily standardized live-animal and preclinical test for ovine scrapie.

scholarly journals Do Bovine Lymphocytes Express a Peculiar Prion Protein?

2002 ◽  
Vol 9 (4) ◽  
pp. 245-252 ◽  
Author(s):  
France Mélot ◽  
Caroline Thielen ◽  
Thouraya Labiet ◽  
Sabine Eisher ◽  
Olivier Jolois ◽  
...  
Keyword(s):  
Prion Protein ◽  
Immune Cells ◽  
Surface Protein ◽  
In Vitro Study ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Spongiform Encephalopathies ◽  
Bovine Lymphocytes

The cellular prion protein (PrPc) is a glycolipid-anchored cell surface protein that usually exhibits three glycosylation states. Its post-translationally modified isoform, PrPsc, is involved in the pathogenesis of various transmissible spongiform encephalopathies (TSEs). In bovine species, BSE infectivity appears to be restricted to the central nervous system; few or no detectable infectivity is found in lymphoid tissues in contrast to scrapie or variant CJD. Since expression of PrPc is a prerequisite for prion replication, we have investigated PrPc expression by bovine immune cells. Lymphocytes from blood and five different lymph organs were isolated from the same animal to assess intra- and interindividual variability of PrPc expression, considering six individuals. As shown by flow cytometry, this expression is absent or weak on granulocytes but is measurable on monocytes, B and T cells from blood and lymph organs. The activation of the bovine cells produces an upregulation of PrPc. The results of our in vitro study of PrPc biosynthesis are consistent with previous studies in other species. Interestingly, western blotting experiments showed only one form of the protein, the diglycosylated band. We propose that the glycosylation state could explain the lack of infectivity of the bovine immune cells.

scholarly journals Experimental scrapie in ‘plt’ mice: an assessment of the role of dendritic-cell migration in the pathogenesis of prion diseases

2007 ◽  
Vol 88 (8) ◽  
pp. 2353-2360 ◽  
Author(s):  
Etienne Levavasseur ◽  
Pat Metharom ◽  
Gauthier Dorban ◽  
Hideki Nakano ◽  
Terutaka Kakiuchi ◽  
...  
Keyword(s):  
Cell Migration ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Receptor System ◽  
Spongiform Encephalopathies ◽  
Dendritic Cell Migration ◽  
Duration Of Disease ◽  
Scrapie Strain ◽  
Secondary Lymphoid Organs

Peripherally acquired transmissible spongiform encephalopathies display strikingly long incubation periods, during which increasing amounts of prions can be detected in lymphoid tissues. While precise sites of peripheral accumulation have been described, the mechanisms of prion transport from mucosa and skin to lymphoid and nervous tissues remain unknown. Because of unique functional abilities, dendritic cells (DCs) have been suspected to participate in prion pathogenesis. In mice inoculated subcutaneously with scrapie-infected DCs, the incubation was shorter when cells were alive as compared with killed cells, suggesting that DC functions may facilitate prion neuroinvasion. However, early propagation in lymphoid tissues seemed not importantly affected by DC vitality. Mutant (plt) mice that have deficient CCL19/CCL21 expression and DC migration displayed similar infection of secondary lymphoid organs as normal mice, regardless of the route of inoculation and scrapie strain. Under certain conditions of transcutaneous inoculation, the incubation and duration of disease were moderately prolonged in plt mice. This was not related to a milder neuropathogenesis, since plt and normal mice were equally susceptible to intracerebral prion challenge. We conclude that peripheral spreading of prions appears poorly dependent on cell migration through the chemokine/receptor system CCL19/CCL21/CCR7, although DCs might be able to help prions reach sites of neuroinvasion.

scholarly journals Temporary Blockade of the Tumor Necrosis Factor Receptor Signaling Pathway Impedes the Spread of Scrapie to the Brain

2002 ◽  
Vol 76 (10) ◽  
pp. 5131-5139 ◽  
Author(s):  
Neil A. Mabbott ◽  
Gillian McGovern ◽  
Martin Jeffrey ◽  
Moira E. Bruce
Keyword(s):  
Tumor Necrosis Factor ◽  
Signaling Pathway ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Receptor ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Necrosis Factor Alpha ◽  
Spongiform Encephalopathies ◽  
Similar Treatment ◽  
Necrosis Factor

ABSTRACT Although the transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases, their agents usually replicate and accumulate in lymphoid tissues long before infection spreads to the central nervous system (CNS). Studies of a mouse scrapie model have shown that mature follicular dendritic cells (FDCs), which express the host prion protein (PrPc), are critical for replication of infection in lymphoid tissues. In the absence of mature FDCs, the spread of infection to the CNS is significantly impaired. Tumor necrosis factor alpha (TNF-α) secretion by lymphocytes is important for maintaining FDC networks, and signaling is mediated through TNF receptor 1 (TNFR-1) expressed on FDCs and/or their precursors. A treatment that blocks TNFR signaling leads to the temporary dedifferentiation of mature FDCs, raising the hypothesis that a similar treatment would significantly delay the peripheral pathogenesis of scrapie. Here, specific neutralization of the TNFR signaling pathway was achieved through treatment with a fusion protein consisting of two soluble human TNFR (huTNFR) (p80) domains linked to the Fc portion of human immunoglobulin G1 (huTNFR:Fc). A single treatment of mice with huTNFR:Fc before or shortly after intraperitoneal injection with the ME7 scrapie strain significantly delayed the onset of disease in the CNS and reduced the early accumulation of disease-specific PrP in the spleen. These effects coincided with a temporary dedifferentiation of mature FDCs within 5 days of huTNFR:Fc treatment. We conclude that treatments that specifically inhibit the TNFR signaling pathway may present an opportunity for early intervention in peripherally transmitted TSEs.

scholarly journals Prion protein β2–α2 loop conformational landscape

2017 ◽  
Vol 114 (36) ◽  
pp. 9617-9622 ◽  
Author(s):  
Enrico Caldarulo ◽  
Alessandro Barducci ◽  
Kurt Wüthrich ◽  
Michele Parrinello
Keyword(s):  
Prion Protein ◽  
Mammalian Species ◽  
Wild Type Mouse ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Free Energy Surface ◽  
Spongiform Encephalopathies ◽  
New Information ◽  
Amyloid Aggregates ◽  
Wide Range

In transmissible spongiform encephalopathies (TSEs), which are lethal neurodegenerative diseases that affect humans and a wide range of other mammalian species, the normal “cellular” prion protein (PrPC) is transformed into amyloid aggregates representing the “scrapie form” of the protein (PrPSc). Continued research on this system is of keen interest, since new information on the physiological function of PrPC in healthy organisms is emerging, as well as new data on the mechanism of the transformation of PrPC to PrPSc. In this paper we used two different approaches: a combination of the well-tempered ensemble (WTE) and parallel tempering (PT) schemes and metadynamics (MetaD) to characterize the conformational free-energy surface of PrPC. The focus of the data analysis was on an 11-residue polypeptide segment in mouse PrPC(121–231) that includes the β2–α2 loop of residues 167–170, for which a correlation between structure and susceptibility to prion disease has previously been described. This study includes wild-type mouse PrPC and a variant with the single-residue replacement Y169A. The resulting detailed conformational landscapes complement in an integrative manner the available experimental data on PrPC, providing quantitative insights into the nature of the structural transition-related function of the β2–α2 loop.

scholarly journals PrPSc detection and infectivity in semen from scrapie-infected sheep

2012 ◽  
Vol 93 (6) ◽  
pp. 1375-1383 ◽  
Author(s):  
Richard Rubenstein ◽  
Marie S. Bulgin ◽  
Binggong Chang ◽  
Sharon Sorensen-Melson ◽  
Robert B. Petersen ◽  
...  
Keyword(s):  
Incubation Time ◽  
Protein Misfolding ◽  
Infected Sheep ◽  
Transmissible Spongiform Encephalopathies ◽  
Animal Testing ◽  
Live Animal ◽  
Transgenic Mouse Line ◽  
Protein Misfolding Cyclic Amplification ◽  
Scrapie Strain ◽  
Short Incubation Time

A scrapie-positive ewe was found in a flock that had been scrapie-free for 13 years, but housed adjacent to scrapie-positive animals, separated by a wire fence. Live animal testing of the entire flock of 24 animals revealed seven more subclinical scrapie-positive ewes. We hypothesized that they may have contracted the disease from scrapie-positive rams used for breeding 4 months prior, possibly through the semen. The genotypes of the ewe flock were highly scrapie-susceptible and the rams were infected with the ‘Caine’ scrapie strain having a short incubation time of 4.3–14.6 months in sheep with 136/171 VQ/VQ and AQ/VQ genotypes. PrPSc accumulates in a variety of tissues in addition to the central nervous system. Although transmission of prion diseases, or transmissible spongiform encephalopathies, has been achieved via peripheral organ or tissue homogenates as well as by blood transfusion, neither infectivity nor PrPSc have been found in semen from scrapie-infected animals. Using serial protein misfolding cyclic amplification followed by a surround optical fibre immunoassay, we demonstrate that semen from rams infected with a short-incubation-time scrapie strain contains prion disease-associated-seeding activity that generated PrPSc in sPMCA (serial protein misfolding cyclic amplification). Injection of the ovinized transgenic mouse line TgSShpPrP with semen from scrapie-infected sheep resulted in PrPSc-seeding activity in clinical and, probably as a result of the low titre, non-clinical mouse brain. These results suggest that the transmissible agent, or at least the seeding activity, for sheep scrapie is present in semen. This may be a strain-specific phenomenon.

scholarly journals Evolution of transmissible spongiform encephalopathy and the prion protein gene (PRNP) in mammals

2020 ◽  
Author(s):  
Brittaney L. Buchanan ◽  
Robert M. Zink
Keyword(s):  
Marine Mammals ◽  
Phylogenetic Signal ◽  
Transmissible Spongiform Encephalopathy ◽  
Mammalian Species ◽  
Species Tree ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Spongiform Encephalopathies ◽  
Wide Range ◽  
D Value

AbstractWildlife managers are concerned with transmissible spongiform encephalopathies (TSEs) as they are currently incurable, always fatal, and have the potential to cross species boundaries. Although a wide range of mammals exhibit TSEs, it is currently unclear whether they are evolutionarily clustered or if TSE+ species are randomly distributed phylogenetically. We tested whether mammalian species with TSEs are phylogenetically underdispersed on a tree derived from 102 PRNP sequences obtained from the Orthologous Mammalian Markers database. We determined that the PRNP tree was topologically congruent with a species tree for these same 102 taxa constructed from 20 aligned gene sequences, excluding the PRNP sequence. Searches in Google Scholar were done to determine whether a species is known to have expressed a TSE. TSEs were present in a variety of orders excluding Chiroptera, Eulipotyphyla, and Lagomorpha and no marine mammals (Artiodactyla) were recorded to have a TSE. We calculated the phylogenetic signal of binary traits (D-Value) to infer if the phylogenetic distribution of TSEs are conserved or dispersed. The occurrence of TSEs in both trees is non-random (Species tree D-value = 0.291; PRNP tree D-value = 0.273), and appears to have arisen independently in the recent history of different mammalian groups. Our findings suggest that the evolution of TSEs develops in groups of species irrespective of PRNP genotype. The evolution of TSEs merits continued exploration at a more in-depth phylogenetic level, as well as the search for genetic combinations that might underlie TSE diseases.

The transmissible spongiform encephalopathies: emerging and declining epidemics

2006 ◽  
Vol 34 (6) ◽  
pp. 1155-1158 ◽  
Author(s):  
J.C. Manson ◽  
E. Cancellotti ◽  
P. Hart ◽  
M.T. Bishop ◽  
R.M. Barron
Keyword(s):  
Neurodegenerative Diseases ◽  
Disease Surveillance ◽  
Chronic Wasting Disease ◽  
Mammalian Species ◽  
Transmissible Spongiform Encephalopathies ◽  
Wasting Disease ◽  
Spongiform Encephalopathies ◽  
Jakob Disease ◽  
And Control

TSEs (transmissible spongiform encephalopathies) are neurodegenerative diseases of various mammalian species, the best known of which include BSE (bovine spongiform encephalopathies) in cattle, CJD (Creutzfeldt–Jakob disease) in humans, scrapie in sheep and CWD (chronic wasting disease) in deer. This review examines the emergence of various TSE strains and their transmission, and discusses disease surveillance and control.

scholarly journals Follicular Dendritic Cell Dedifferentiation by Treatment with an Inhibitor of the Lymphotoxin Pathway Dramatically Reduces Scrapie Susceptibility

2003 ◽  
Vol 77 (12) ◽  
pp. 6845-6854 ◽  
Author(s):  
Neil A. Mabbott ◽  
Janice Young ◽  
Irene McConnell ◽  
Moira E. Bruce
Keyword(s):  
Nervous System ◽  
Follicular Dendritic Cell ◽  
Transmissible Spongiform Encephalopathies ◽  
Lymphoid Tissues ◽  
Mesenteric Lymph Nodes ◽  
Spongiform Encephalopathies ◽  
Oral Inoculation ◽  
Follicular Dendritic ◽  
Route Of Exposure ◽  
Β Receptor

ABSTRACT Transmissible spongiform encephalopathies (TSEs) may be acquired peripherally, in which case infectivity usually accumulates in lymphoid tissues before dissemination to the nervous system. Studies of mouse scrapie models have shown that mature follicular dendritic cells (FDCs), expressing the host prion protein (PrPc), are critical for replication of infection in lymphoid tissues and subsequent neuroinvasion. Since FDCs require lymphotoxin signals from B lymphocytes to maintain their differentiated state, blockade of this stimulation with a lymphotoxin β receptor-immunoglobulin fusion protein (LTβR-Ig) leads to their temporary dedifferentiation. Here, a single treatment with LTβR-Ig before intraperitoneal scrapie inoculation blocked the early accumulation of infectivity and disease-specific PrP (PrPSc) within the spleen and substantially reduced disease susceptibility. These effects coincided with an absence of FDCs in the spleen for ca. 28 days after treatment. Although the period of FDC dedifferentiation was extended to at least 49 days by consecutive LTβR-Ig treatments, this had little added protective benefit after injection with a moderate dose of scrapie. We also demonstrate that mature FDCs are critical for the transmission of scrapie from the gastrointestinal tract. Treatment with LTβR-Ig before oral scrapie inoculation blocked PrPSc accumulation in Peyer's patches and mesenteric lymph nodes and prevented neuroinvasion. However, treatment 14 days after oral inoculation did not affect survival time or susceptibility, suggesting that infectivity may have already spread to the peripheral nervous system. Although manipulation of FDCs may offer a potential approach for early intervention in peripherally acquired TSEs, these data suggest that the duration of the treatment window may vary widely depending on the route of exposure.

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