scholarly journals Lymphotoxin-α- and Lymphotoxin-β-Deficient Mice Differ in Susceptibility to Scrapie: Evidence against Dendritic Cell Involvement in Neuroinvasion

2002 ◽  
Vol 76 (9) ◽  
pp. 4357-4363 ◽  
Author(s):  
Michael B. A. Oldstone ◽  
Richard Race ◽  
Diane Thomas ◽  
Hanna Lewicki ◽  
Dirk Homann ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Oral Intake ◽  
Infectious Agent ◽  
Lymphoid Cells ◽  
Current Evidence ◽  
Spongiform Encephalopathy ◽  
Lymphoid Tissues ◽  
Mesenteric Lymph Nodes

ABSTRACT Transmissible spongiform encephalopathy or prion diseases are fatal neurodegenerative disorders of humans and animals often initiated by oral intake of an infectious agent. Current evidence suggests that infection occurs initially in the lymphoid tissues and subsequently in the central nervous system (CNS). The identity of infected lymphoid cells remains controversial, but recent studies point to the involvement of both follicular dendritic cells (FDC) and CD11c+ lymphoid dendritic cells. FDC generation and maintenance in germinal centers is dependent on lymphotoxin alpha (LT-α) and LT-β signaling components. We report here that by the oral route, LT-α −/− mice developed scrapie while LT-β −/− mice did not. Furthermore, LT-α −/− mice had a higher incidence and shorter incubation period for developing disease following inoculation than did LT-β −/− mice. Transplantation of lymphoid tissues from LT-β −/− mice, which have cervical and mesenteric lymph nodes, into LT-α −/− mice, which do not, did not alter the incidence of CNS scrapie. In other studies, a virus that is tropic for and alters functions of CD11c+ cells did not alter the kinetics of neuroinvasion of scrapie. Our results suggest that neither FDC nor CD11c+ cells are essential for neuroinvasion after high doses of RML scrapie. Further, it is possible that an as yet unidentified cell found more abundantly in LT-α −/− than in LT-β −/− mice may assist in the amplification of scrapie infection in the periphery and favor susceptibility to CNS disease following peripheral routes of infection.

scholarly journals Transmissible spongiform encephalopathy strain, PrP genotype and brain region all affect the degree of glycosylation of PrPSc

2005 ◽  
Vol 86 (1) ◽  
pp. 241-246 ◽  
Author(s):  
Robert A. Somerville ◽  
Scott Hamilton ◽  
Karen Fernie
Keyword(s):  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Infectious Agent ◽  
Host Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Major Influence ◽  
Spongiform Encephalopathy ◽  
Phenotypic Properties ◽  
Spongiform Encephalopathies ◽  
Diagnostic Potential

Transmissible spongiform encephalopathies (TSEs), sometimes known as prion diseases, are caused by an infectious agent whose molecular properties have not been determined. Traditionally, different strains of TSE diseases are characterized by a series of phenotypic properties after passage in experimental animals. More recently it has been recognized that diversity in the degree to which an abnormal form of the host protein PrP, denoted PrPSc, is glycosylated and the migration of aglycosyl forms of PrPSc on immunoblots may have some differential diagnostic potential. It has been recognized that these factors are affected by the strain of TSE agent but also by other factors, e.g. location within the brain. This study shows in some cases, but not others, that host PrP genotype has a major influence on the degree of PrPSc glycosylation and migration on gels and provides further evidence of the effect of brain location. Accordingly both the degree of glycosylation and the apparent molecular mass of PrPSc may be of some value for differential diagnosis between TSE strains, but only when host effects are taken into account. Furthermore, the data inform the debate about how these differences arise, and favour hypotheses proposing that TSE agents affect glycosylation of PrP during its biosynthesis.

scholarly journals Neuroinvasion by Scrapie following Inoculation via the Skin Is Independent of Migratory Langerhans Cells

2005 ◽  
Vol 79 (3) ◽  
pp. 1888-1897 ◽  
Author(s):  
Joanne Mohan ◽  
Moira E. Bruce ◽  
Neil A. Mabbott
Keyword(s):  
Lymph Node ◽  
Langerhans Cells ◽  
Transmissible Spongiform Encephalopathy ◽  
Effective Means ◽  
Infectious Agent ◽  
Spongiform Encephalopathy ◽  
Lymphoid Tissues ◽  
Wild Type ◽  
Draining Lymph Node

ABSTRACT Many natural transmissible spongiform encephalopathy (TSE) infections are likely to be acquired peripherally, and studies in mice show that skin scarification is an effective means of scrapie transmission. After peripheral exposure, TSE agents usually accumulate in lymphoid tissues before spreading to the brain. The mechanisms of TSE transport to lymphoid tissues are not known. Langerhans cells (LCs) reside in the epidermis and migrate to the draining lymph node after encountering antigen. To investigate the potential role of LCs in scrapie transportation from the skin, we utilized mouse models in which their migration was blocked either due to CD40 ligand deficiency (CD40L−/− mice) or after caspase-1 inhibition. We show that the early accumulation of scrapie infectivity in the draining lymph node and subsequent neuroinvasion was not impaired in mice with blocked LC migration. Thus, LCs are not involved in TSE transport from the skin. After intracerebral inoculation with scrapie, wild-type mice and CD40L−/− mice develop clinical disease with similar incubation periods. However, after inoculation via skin scarification CD40L−/− mice develop disease significantly earlier than do wild-type mice. The shorter incubation period in CD40L−/− mice is unexpected and suggests that a CD40L-dependent mechanism is involved in impeding scrapie pathogenesis. In vitro studies demonstrated that LCs have the potential to acquire and degrade protease-resistant prion protein, which is thought to be a component of the infectious agent. Taken together, these data suggest that LCs are not involved in scrapie transport to draining lymphoid tissues but might have the potential to degrade scrapie in the skin.

scholarly journals Identification of Misfolded Proteins in Body Fluids for the Diagnosis of Prion Diseases

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Francesca Properzi ◽  
Maurizio Pocchiari
Keyword(s):  
Prion Protein ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Clinical Signs ◽  
Meat Products ◽  
Silent Period ◽  
Infectious Agent ◽  
Body Fluids ◽  
Cellular Prion Protein ◽  
Spongiform Encephalopathy

Transmissible spongiform encephalopathy (TSE) or prion diseases are fatal rare neurodegenerative disorders affecting man and animals and caused by a transmissible infectious agent. TSE diseases are characterized by spongiform brain lesions with neuronal loss and the abnormal deposition in the CNS, and to less extent in other tissues, of an insoluble and protease resistant form of the cellular prion protein (PrPC), namedPrPTSE. In man, TSE diseases affect usually people over 60 years of age with no evident disease-associated risk factors. In some cases, however, TSE diseases are unequivocally linked to infectious episodes related to the use of prion-contaminated medicines, medical devices, or meat products as in the variant Creutzfeldt-Jakob disease (CJD). Clinical signs occur months or years after infection, and during this silent periodPrPTSE, the only reliable marker of infection, is not easily measurable in blood or other accessible tissues or body fluids causing public health concerns. To overcome the limit ofPrPTSEdetection, several highly sensitive assays have been developed, but attempts to apply these techniques to blood of infected hosts have been unsuccessful or not yet validated. An update on the latest advances for the detection of misfolded prion protein in body fluids is provided.

scholarly journals Detection of RNA in the Plasma of Patients with Sporadic Creutzfeldt–Jakob Disease, Gerstmann–Straüssler Syndrome and Other Non-Transmissible Spongiform Encephalopathy Brain Disorders

2010 ◽  
Vol 3 ◽  
pp. MBI.S4043
Author(s):  
Kazuo Tsukui ◽  
Yasushi Iwasaki ◽  
Masamitsu Nagaoka ◽  
Kenji Tadokoro
Keyword(s):  
Prion Protein ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Infectious Agent ◽  
Brain Homogenate ◽  
Proteinase K ◽  
Spongiform Encephalopathy ◽  
Brain Disorders ◽  
Rna Molecules ◽  
Jakob Disease

The infectious agent of transmissible spongiform encephalopathy (TSE) was assumed to be the aggregate of abnormal prion protein isoform (PrPsc). We observed that lowering the pH of 3% SDS-inoculated plasma or brain homogenate after PK digestion to 4.5 (acidic SDS condition) enabled to precipitate proteinase K-resistant prion protein (PrPres) in plasma as well as PrPres in the brain with synthetic poly-A RNA as affinity aggregate. Therefore, we determined if RNA molecules could be used for discriminating TSE patients from healthy individuals. We also examined the plasma of patients with classical Creutzfeldt–Jakob disease (CJD) and other brain disorders who were not diagnosed with TSE. The results indicated that RNA approximately 1.5–2.0 kb in length was commonly observed in the plasma of patients with brain disorders but was not detected in the plasma of healthy volunteers. Enhanced expression of RNA and its protection from endogenous nucleases might occur in the former group of patients. Moreover, we speculate that the non-transmissible neuronal disorders overlap with prion diseases.

scholarly journals Four types of scrapie in goats differentiated from each other and bovine spongiform encephalopathy by biochemical methods

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Jan P. M. Langeveld ◽  
Laura Pirisinu ◽  
Jorg G. Jacobs ◽  
Maria Mazza ◽  
Isabelle Lantier ◽  
...  
Keyword(s):  
Bovine Spongiform Encephalopathy ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Small Ruminants ◽  
Infectious Agent ◽  
Spongiform Encephalopathy ◽  
Prion Strain ◽  
Amino Acid Region ◽  
Proteolytic Resistance ◽  
Fatal Consequence

AbstractScrapie in goats has been known since 1942, the archetype of prion diseases in which only prion protein (PrP) in misfolded state (PrPSc) acts as infectious agent with fatal consequence. Emergence of bovine spongiform encephalopathy (BSE) with its zoonotic behaviour and detection in goats enhanced fears that its source was located in small ruminants. However, in goats knowledge on prion strain typing is limited. A European-wide study is presented concerning the biochemical phenotypes of the protease resistant fraction of PrPSc (PrPres) in over thirty brain isolates from transmissible spongiform encephalopathy (TSE) affected goats collected in seven countries. Three different scrapie forms were found: classical scrapie (CS), Nor98/atypical scrapie and one case of CH1641 scrapie. In addition, CS was found in two variants—CS-1 and CS-2 (mainly Italy)—which differed in proteolytic resistance of the PrPresN-terminus. Suitable PrPres markers for discriminating CH1641 from BSE (C-type) appeared to be glycoprofile pattern, presence of two triplets instead of one, and structural (in)stability of its core amino acid region. None of the samples exhibited BSE like features. BSE and these four scrapie types, of which CS-2 is new, can be recognized in goats with combinations of a set of nine biochemical parameters.

scholarly journals Migrating intestinal dendritic cells transport PrPSc from the gut

2002 ◽  
Vol 83 (1) ◽  
pp. 267-271 ◽  
Author(s):  
Fang-Ping Huang ◽  
Christine F. Farquhar ◽  
Neil A. Mabbott ◽  
Moira E. Bruce ◽  
G. Gordon MacPherson
Keyword(s):  
Dendritic Cells ◽  
Intestinal Wall ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Lymphoid Tissues ◽  
Mesenteric Lymph Nodes ◽  
Spongiform Encephalopathies ◽  
Germinal Centres

Bovine spongiform encephalopathy, variant Creutzfeldt–Jakob disease (vCJD) and possibly also sheep scrapie are orally acquired transmissible spongiform encephalopathies (TSEs). TSE agents usually replicate in lymphoid tissues before they spread into the central nervous system. In mouse TSE models PrPc-expressing follicular dendritic cells (FDCs) resident in lymphoid germinal centres are essential for replication, and in their absence neuroinvasion is impaired. Disease-associated forms of PrP (PrPSc), a biochemical marker for TSE infection, also accumulate on FDCs in the lymphoid tissues of patients with vCJD and sheep with natural scrapie. TSE transport mechanisms between gut lumen and germinal centres are unknown. Migratory bone marrow-derived dendritic cells (DCs), entering the intestinal wall from blood, sample antigens from the gut lumen and carry them to mesenteric lymph nodes. Here we show that DCs acquire PrPSc in vitro, and transport intestinally administered PrPSc directly into lymphoid tissues in vivo. These studies suggest that DCs are a cellular bridge between the gut lumen and the lymphoid TSE replicative machinery.

scholarly journals PrP P102L and Nearby Lysine Mutations Promote Spontaneous In Vitro Formation of Transmissible Prions

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Allison Kraus ◽  
Gregory J. Raymond ◽  
Brent Race ◽  
Katrina J. Campbell ◽  
Andrew G. Hughson ◽  
...  
Keyword(s):  
Prion Protein ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Clinical Signs ◽  
Protein Aggregates ◽  
Structural Features ◽  
Spongiform Encephalopathy ◽  
Specific Sequence

ABSTRACT Accumulation of fibrillar protein aggregates is a hallmark of many diseases. While numerous proteins form fibrils by prion-like seeded polymerization in vitro, only some are transmissible and pathogenic in vivo. To probe the structural features that confer transmissibility to prion protein (PrP) fibrils, we have analyzed synthetic PrP amyloids with or without the human prion disease-associated P102L mutation. The formation of infectious prions from PrP molecules in vitro has required cofactors and/or unphysiological denaturing conditions. Here, we demonstrate that, under physiologically compatible conditions without cofactors, the P102L mutation in recombinant hamster PrP promoted prion formation when seeded by minute amounts of scrapie prions in vitro. Surprisingly, combination of the P102L mutation with charge-neutralizing substitutions of four nearby lysines promoted spontaneous prion formation. When inoculated into hamsters, both of these types of synthetic prions initiated substantial accumulation of prion seeding activity and protease-resistant PrP without transmissible spongiform encephalopathy (TSE) clinical signs or notable glial activation. Our evidence suggests that PrP's centrally located proline and lysine residues act as conformational switches in the in vitro formation of transmissible PrP amyloids. IMPORTANCE Many diseases involve the damaging accumulation of specific misfolded proteins in thread-like aggregates. These threads (fibrils) are capable of growing on the ends by seeding the refolding and incorporation of the normal form of the given protein. In many cases such aggregates can be infectious and propagate like prions when transmitted from one individual host to another. Some transmitted aggregates can cause fatal disease, as with human iatrogenic prion diseases, while other aggregates appear to be relatively innocuous. The factors that distinguish infectious and pathogenic protein aggregates from more innocuous ones are poorly understood. Here we have compared the combined effects of prion seeding and mutations of prion protein (PrP) on the structure and transmission properties of synthetic PrP aggregates. Our results highlight the influence of specific sequence features in the normally unstructured region of PrP that influence the infectious and neuropathogenic properties of PrP-derived aggregates.

scholarly journals Clinical, neuropathological and immunohistochemical features of sporadic and variant forms of Creutzfeldt–Jakob disease in the squirrel monkey (Saimiri sciureus)

2007 ◽  
Vol 88 (2) ◽  
pp. 688-695 ◽  
Author(s):  
Lawrence Williams ◽  
Paul Brown ◽  
James Ironside ◽  
Susan Gibson ◽  
Robert Will ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Transmissible Spongiform Encephalopathy ◽  
Clinicopathological Characteristics ◽  
Saimiri Sciureus ◽  
Spongiform Encephalopathy ◽  
Lymphoid Tissues ◽  
Incubation Periods ◽  
Clinical Surveillance ◽  
Jakob Disease ◽  
Different Strains

The squirrel monkey (Saimiri sciureus) has been shown to be nearly as susceptible as the chimpanzee to experimentally induced Creutzfeldt–Jakob disease (CJD), and has been used extensively in diagnostic and pathogenetic studies. However, no information is available concerning the clinicopathological characteristics of different strains of human transmissible spongiform encephalopathy (TSE) in this species, in particular, strains of sporadic and variant CJD (sCJD and vCJD, respectively). Brain homogenates from patients with sCJD or vCJD were inoculated intracerebrally at dilutions of 10−1 or 10−3 into the left frontal cortex of squirrel monkeys. Animals were kept under continuous clinical surveillance during the preclinical and clinical phases of disease, and regularly underwent standardized behavioural testing. Brains from three animals in the sCJD and vCJD groups were examined histopathologically and immunohistochemically for the presence of pathognomonic misfolded protein (PrPTSE). Overall, incubation periods and durations of illness were slightly shorter in monkeys infected with sCJD than in those infected with vCJD, but the earliest signs of illness (ataxia and tremors) were the same in both groups. Clinical disease in the sCJD monkeys was somewhat more severe and of shorter duration. Post-mortem examinations revealed distinctive patterns of spongiform change and PrPTSE distribution in the brains of sCJD and vCJD animals, similar to those seen in humans except that amyloid plaques were not present. PrPTSE was uniformly absent from peripheral lymphoid tissues in both groups of animals. Human strains of sCJD and vCJD cause distinguishable clinicopathological features in the squirrel monkey that can provide a baseline for the evaluation of future therapeutic studies.

scholarly journals Characterization of the effect of heat on agent strains of the transmissible spongiform encephalopathies

2011 ◽  
Vol 92 (7) ◽  
pp. 1738-1748 ◽  
Author(s):  
Robert A. Somerville ◽  
Nicola Gentles
Keyword(s):  
Conformational Changes ◽  
High Resistance ◽  
Thermal Inactivation ◽  
Transmissible Spongiform Encephalopathy ◽  
Infectious Agent ◽  
Host Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Heat Inactivation ◽  
Spongiform Encephalopathy ◽  
Spongiform Encephalopathies

The causal agents of the transmissible spongiform encephalopathy (TSE) diseases, sometimes called prion diseases, are characterized by high resistance to inactivation with heat. Results from thermal inactivation experiments on nine TSE strains, seven passaged in two PrP genotypes, showed differences in sensitivity to heat inactivation ranging over 17 °C. In addition, the rate of inactivation with increasing temperature varied between TSE models. In some cases passage in an alternative PrP genotype had little effect on the resulting inactivation properties, but for others the infectious agent was inactivated at lower temperatures. No strain with higher thermostability properties was selected. The effect of mixing two TSE strains, to see whether their properties were affected through interaction with each other, was also examined. The results showed that both strains behaved as expected from the behaviour of the unmixed controls, and that the strain responsible for inducing TSE disease could be identified. There was no evidence of a direct effect on intrinsic strain properties. Overall, the results illustrate the diversity in properties of TSE strains. They require intrinsic molecular properties of TSE agents to accommodate high resistance to inactivation and a mechanism, independent of the host, to directly encode these differences. These findings are more readily reconciled with models of TSE agents with two separate components, one of which is independent of the host and comprises a TSE-specific nucleic acid, than with models based solely on conformational changes to a host protein.

scholarly journals Peripheral CD103+ dendritic cells form a unified subset developmentally related to CD8α+ conventional dendritic cells

2010 ◽  
Vol 207 (4) ◽  
pp. 823-836 ◽  
Author(s):  
Brian T. Edelson ◽  
Wumesh KC ◽  
Richard Juang ◽  
Masako Kohyama ◽  
Loralyn A. Benoit ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Transcription Factor ◽  
Lymph Nodes ◽  
Sendai Virus ◽  
Pulmonary Inflammation ◽  
Lymphoid Organ ◽  
Contact Hypersensitivity ◽  
Lymphoid Tissues ◽  
Mesenteric Lymph Nodes ◽  
Normal Contact

Although CD103-expressing dendritic cells (DCs) are widely present in nonlymphoid tissues, the transcription factors controlling their development and their relationship to other DC subsets remain unclear. Mice lacking the transcription factor Batf3 have a defect in the development of CD8α+ conventional DCs (cDCs) within lymphoid tissues. We demonstrate that Batf3−/− mice also lack CD103+CD11b− DCs in the lung, intestine, mesenteric lymph nodes (MLNs), dermis, and skin-draining lymph nodes. Notably, Batf3−/− mice displayed reduced priming of CD8 T cells after pulmonary Sendai virus infection, with increased pulmonary inflammation. In the MLNs and intestine, Batf3 deficiency resulted in the specific lack of CD103+CD11b− DCs, with the population of CD103+CD11b+ DCs remaining intact. Batf3−/− mice showed no evidence of spontaneous gastrointestinal inflammation and had a normal contact hypersensitivity (CHS) response, despite previous suggestions that CD103+ DCs were required for immune homeostasis in the gut and CHS. The relationship between CD8α+ cDCs and nonlymphoid CD103+ DCs implied by their shared dependence on Batf3 was further supported by similar patterns of gene expression and their shared developmental dependence on the transcription factor Irf8. These data provide evidence for a developmental relationship between lymphoid organ–resident CD8α+ cDCs and nonlymphoid CD103+ DCs.

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