scholarly journals The ultrastructure of infectious L-type bovine spongiform encephalopathy prions constrains molecular models

2021 ◽  
Vol 17 (6) ◽  
pp. e1009628
Author(s):  
Razieh Kamali-Jamil ◽  
Ester Vázquez-Fernández ◽  
Brian Tancowny ◽  
Vineet Rathod ◽  
Sara Amidian ◽  
...  

Bovine spongiform encephalopathy (BSE) is a prion disease of cattle that is caused by the misfolding of the cellular prion protein (PrPC) into an infectious conformation (PrPSc). PrPC is a predominantly α-helical membrane protein that misfolds into a β-sheet rich, infectious state, which has a high propensity to self-assemble into amyloid fibrils. Three strains of BSE prions can cause prion disease in cattle, including classical BSE (C-type) and two atypical strains, named L-type and H-type BSE. To date, there is no detailed information available about the structure of any of the infectious BSE prion strains. In this study, we purified L-type BSE prions from transgenic mouse brains and investigated their biochemical and ultrastructural characteristics using electron microscopy, image processing, and immunogold labeling techniques. By using phosphotungstate anions (PTA) to precipitate PrPSc combined with sucrose gradient centrifugation, a high yield of proteinase K-resistant BSE amyloid fibrils was obtained. A morphological examination using electron microscopy, two-dimensional class averages, and three-dimensional reconstructions revealed two structural classes of L-type BSE amyloid fibrils; fibrils that consisted of two protofilaments with a central gap and an average width of 22.5 nm and one-protofilament fibrils that were 10.6 nm wide. The one-protofilament fibrils were found to be more abundant compared to the thicker two-protofilament fibrils. Both fibrillar assemblies were successfully decorated with monoclonal antibodies against N- and C-terminal epitopes of PrP using immunogold-labeling techniques, confirming the presence of polypeptides that span residues 100–110 to 227–237. The fact that the one-protofilament fibrils contain both N- and C-terminal PrP epitopes constrains molecular models for the structure of the infectious conformer in favour of a compact four-rung β-solenoid fold.

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 232 ◽  
Author(s):  
Paweł Liberski ◽  
Agata Gajos ◽  
Beata Sikorska ◽  
Shirley Lindenbaum

Kuru, the first human prion disease was transmitted to chimpanzees by D. Carleton Gajdusek (1923–2008). In this review, we summarize the history of this seminal discovery, its anthropological background, epidemiology, clinical picture, neuropathology, and molecular genetics. We provide descriptions of electron microscopy and confocal microscopy of kuru amyloid plaques retrieved from a paraffin-embedded block of an old kuru case, named Kupenota. The discovery of kuru opened new vistas of human medicine and was pivotal in the subsequent transmission of Creutzfeldt–Jakob disease, as well as the relevance that bovine spongiform encephalopathy had for transmission to humans. The transmission of kuru was one of the greatest contributions to biomedical sciences of the 20th century.


2020 ◽  
Vol 21 (12) ◽  
pp. 4246 ◽  
Author(s):  
Sae-Young Won ◽  
Yong-Chan Kim ◽  
Byung-Hoon Jeong

Bovine spongiform encephalopathy (BSE) is a prion disease characterized by spongiform degeneration and astrocytosis in the brain. Unlike classical BSE, which is caused by prion-disease-contaminated meat and bone meal, the cause of atypical BSE has not been determined. Since previous studies have reported that the somatic mutation in the human prion protein gene (PRNP) has been linked to human prion disease, the somatic mutation of the PRNP gene was presumed to be one cause of prion disease. However, to the best of our knowledge, the somatic mutation of this gene in cattle has not been investigated to date. We investigated somatic mutations in a total of 58 samples, including peripheral blood; brain tissue including the medulla oblongata, cerebellum, cortex, and thalamus; and skin tissue in 20 individuals from each breed using pyrosequencing. In addition, we estimated the deleterious effect of the K211 somatic mutation on bovine prion protein by in silico evaluation tools, including PolyPhen-2 and PANTHER. We found a high rate of K211 somatic mutations of the bovine PRNP gene in the medulla oblongata of three Holsteins (10% ± 4.4%, 28% ± 2%, and 19.55% ± 3.1%). In addition, in silico programs showed that the K211 somatic mutation was damaging. To the best of our knowledge, this study is the first to investigate K211 somatic mutations of the bovine PRNP gene that are associated with potential BSE progression.


Brain ◽  
2020 ◽  
Vol 143 (5) ◽  
pp. 1512-1524 ◽  
Author(s):  
Ilaria Vanni ◽  
Laura Pirisinu ◽  
Claudia Acevedo-Morantes ◽  
Razieh Kamali-Jamil ◽  
Vineet Rathod ◽  
...  

Abstract Prions are transmissible agents causing lethal neurodegenerative diseases that are composed of aggregates of misfolded cellular prion protein (PrPSc). Despite non-fibrillar oligomers having been proposed as the most infectious prion particles, prions purified from diseased brains usually consist of large and fibrillar PrPSc aggregates, whose protease-resistant core (PrPres) encompasses the whole C-terminus of PrP. In contrast, PrPSc from Gerstmann-Sträussler-Scheinker disease associated with alanine to valine substitution at position 117 (GSS-A117V) is characterized by a small protease-resistant core, which is devoid of the C-terminus. We thus aimed to investigate the role of this unusual PrPSc in terms of infectivity, strain characteristics, and structural features. We found, by titration in bank voles, that the infectivity of GSS-A117V is extremely high (109.3 ID50 U/g) and is resistant to treatment with proteinase K (109.0 ID50 U/g). We then purified the proteinase K-resistant GSS-A117V prions and determined the amount of infectivity and PrPres in the different fractions, alongside the morphological characteristics of purified PrPres aggregates by electron microscopy. Purified pellet fractions from GSS-A117V contained the expected N- and C-terminally cleaved 7 kDa PrPres, although the yield of PrPres was low. We found that this low yield depended on the low density/small size of GSS-A117V PrPres, as it was mainly retained in the last supernatant fraction. All fractions were highly infectious, thus confirming the infectious nature of the 7 kDa PrPres, with infectivity levels that directly correlated with the PrPres amount detected. Finally, electron microscopy analysis of these fractions showed no presence of amyloid fibrils, but only very small and indistinct, non-fibrillar PrPresparticles were detected and confirmed to contain PrP via immunogold labelling. Our study demonstrates that purified aggregates of 7 kDa PrPres, spanning residues ∼90–150, are highly infectious oligomers that encode the biochemical and biological strain features of the original sample. Overall, the autocatalytic behaviour of the prion oligomers reveals their role in the propagation of neurodegeneration in patients with Gerstmann-Sträussler-Scheinker disease and implies that the C-terminus of PrPSc is dispensable for infectivity and strain features for this prion strain, uncovering the central PrP domain as the minimal molecular component able to encode infectious prions. These findings are consistent with the hypothesis that non-fibrillar prion particles are highly efficient propagators of disease and provide new molecular and morphological constraints on the structure of infectious prions.


2005 ◽  
Vol 4 (10) ◽  
pp. 273-278
Author(s):  
Steve Dealler

Steve Dealler is a medical microbiologist with Morecambe Bay Hospitals NHS Trust. His work on on the diagnosis, epidemiology and potential treatment of transmissible spongiform encephalopathies has brought him inter-national recognition. He has been at the forefront of work on the epidemiology of human food containing the vector for bovine spongiform encephalopathy (BSE), and the development of prophylaxis against variant Creutzfeldt-Jakob disease (vCJD). He is currently working on a potential treatment, pentosan polysulphate. Here he describes the current state of knowledge in the battle against this devastating disease and the political inertia that frustrated earlier attempts to prevent the epidemic.


2008 ◽  
Vol 82 (7) ◽  
pp. 3697-3701 ◽  
Author(s):  
Qingzhong Kong ◽  
Mengjie Zheng ◽  
Cristina Casalone ◽  
Liuting Qing ◽  
Shenghai Huang ◽  
...  

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.


Transfusion ◽  
2010 ◽  
Vol 50 (2) ◽  
pp. 452-466 ◽  
Author(s):  
Edgar Holznagel ◽  
Barbara Yutzy ◽  
Walter Schulz-Schaeffer ◽  
Kay-Martin Hanschman ◽  
Andreas Stuke ◽  
...  

1998 ◽  
Vol 80 (12) ◽  
pp. 909-911 ◽  
Author(s):  
James Ironside ◽  
Jeanne Bell ◽  
Paul Giangrande ◽  
Christopher Ludlam ◽  
Margaret M. Esiri ◽  
...  

SummaryIn 1996, the CJD surveillance unit in Edinburgh, UK described nvCJD which was thought to be the human equivalent of bovine spongiform encephalopathy (BSE). The identification of prion protein in the tonsil of an affected individual has raised the question of transmission of nvCJD via blood products. This study examines the post mortem brains of 33 patients who were treated with clotting factor concentrate of predominately UK donor source during the years 1962-1995. The brains were examined by conventional histological methods and also for the prion protein using monoclonal antibodies KG9 and 3F4. No evidence of spongiform encephalopathy was found and the immunocytochemistry was negative for PrP in all cases. It is concluded that, at present, there is no evidence for the transmission of nvCJD via clotting factor concentrate to patients with haemophilia.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Zerui Wang ◽  
Kefeng Qin ◽  
Manuel V. Camacho ◽  
Ignazio Cali ◽  
Jue Yuan ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document