scholarly journals Chronic wasting disease (CWD) prion strains evolve via adaptive diversification of conformers in hosts expressing prion protein polymorphisms

2020 ◽  
Vol 295 (15) ◽  
pp. 4985-5001 ◽  
Author(s):  
Camilo Duque Velásquez ◽  
Chae Kim ◽  
Tracy Haldiman ◽  
Chiye Kim ◽  
Allen Herbst ◽  
...  

Chronic wasting disease (CWD) is caused by an unknown spectrum of prions and has become enzootic in populations of cervid species that express cellular prion protein (PrPC) molecules varying in amino acid composition. These PrPC polymorphisms can affect prion transmission, disease progression, neuropathology, and emergence of new prion strains, but the mechanistic steps in prion evolution are not understood. Here, using conformation-dependent immunoassay, conformation stability assay, and protein-misfolding cyclic amplification, we monitored the conformational and phenotypic characteristics of CWD prions passaged through deer and transgenic mice expressing different cervid PrPC polymorphisms. We observed that transmission through hosts with distinct PrPC sequences diversifies the PrPCWD conformations and causes a shift toward oligomers with defined structural organization, replication rate, and host range. When passaged in host environments that restrict prion replication, distinct co-existing PrPCWD conformers underwent competitive selection, stabilizing a new prion strain. Nonadaptive conformers exhibited unstable replication and accumulated only to low levels. These results suggest a continuously evolving diversity of CWD conformers and imply a critical interplay between CWD prion plasticity and PrPC polymorphisms during prion strain evolution.

2021 ◽  
Vol 17 (7) ◽  
pp. e1009795
Author(s):  
Samia Hannaoui ◽  
Elizabeth Triscott ◽  
Camilo Duque Velásquez ◽  
Sheng Chun Chang ◽  
Maria Immaculata Arifin ◽  
...  

Chronic wasting disease (CWD) is a prion disease affecting cervids. Polymorphisms in the prion protein gene can result in extended survival of CWD-infected animals. However, the impact of polymorphisms on cellular prion protein (PrPC) and prion properties is less understood. Previously, we characterized the effects of a polymorphism at codon 116 (A>G) of the white-tailed deer (WTD) prion protein and determined that it destabilizes PrPC structure. Comparing CWD isolates from WTD expressing homozygous wild-type (116AA) or heterozygous (116AG) PrP, we found that 116AG-prions were conformationally less stable, more sensitive to proteases, with lower seeding activity in cell-free conversion and reduced infectivity. Here, we aimed to understand CWD strain emergence and adaptation. We show that the WTD-116AG isolate contains two different prion strains, distinguished by their host range, biochemical properties, and pathogenesis from WTD-116AA prions (Wisc-1). Serial passages of WTD-116AG prions in tg(CerPrP)1536+/+ mice overexpressing wild-type deer-PrPC revealed two populations of mice with short and long incubation periods, respectively, and remarkably prolonged clinical phase upon inoculation with WTD-116AG prions. Inoculation of serially diluted brain homogenates confirmed the presence of two strains in the 116AG isolate with distinct pathology in the brain. Interestingly, deglycosylation revealed proteinase K-resistant fragments with different electrophoretic mobility in both tg(CerPrP)1536+/+ mice and Syrian golden hamsters infected with WTD-116AG. Infection of tg60 mice expressing deer S96-PrP with 116AG, but not Wisc-1 prions induced clinical disease. On the contrary, bank voles resisted 116AG prions, but not Wisc-1 infection. Our data indicate that two strains co-existed in the WTD-116AG isolate, expanding the variety of CWD prion strains. We argue that the 116AG isolate does not contain Wisc-1 prions, indicating that the presence of 116G-PrPC diverted 116A-PrPC from adopting a Wisc-1 structure. This can have important implications for their possible distinct capacities to cross species barriers into both cervids and non-cervids.


Author(s):  
Juan Carlos Espinosa ◽  
Alba Marín-Moreno ◽  
Patricia Aguilar-Calvo ◽  
Sylvie L Benestad ◽  
Olivier Andreoletti ◽  
...  

Abstract Although experimental transmission of bovine spongiform encephalopathy (BSE) to pigs and transgenic mice expressing pig cellular prion protein (PrPC) (porcine PrP [PoPrP]–Tg001) has been described, no natural cases of prion diseases in pig were reported. This study analyzed pig-PrPC susceptibility to different prion strains using PoPrP-Tg001 mice either as animal bioassay or as substrate for protein misfolding cyclic amplification (PMCA). A panel of isolates representatives of different prion strains was selected, including classic and atypical/Nor98 scrapie, atypical-BSE, rodent scrapie, human Creutzfeldt-Jakob-disease and classic BSE from different species. Bioassay proved that PoPrP-Tg001-mice were susceptible only to the classic BSE agent, and PMCA results indicate that only classic BSE can convert pig-PrPC into scrapie-type PrP (PrPSc), independently of the species origin. Therefore, conformational flexibility constraints associated with pig-PrP would limit the number of permissible PrPSc conformations compatible with pig-PrPC, thus suggesting that pig-PrPC may constitute a paradigm of low conformational flexibility that could confer high resistance to the diversity of prion strains.


2007 ◽  
Vol 81 (17) ◽  
pp. 9605-9608 ◽  
Author(s):  
Timothy D. Kurt ◽  
Matthew R. Perrott ◽  
Carol J. Wilusz ◽  
Jeffrey Wilusz ◽  
Surachai Supattapone ◽  
...  

ABSTRACT Chronic wasting disease (CWD) of cervids is associated with conversion of the normal cervid prion protein, PrPC, to a protease-resistant conformer, PrPCWD. Here we report the use of both nondenaturing amplification and protein-misfolding cyclic amplification (PMCA) to amplify PrPCWD in vitro. Normal brains from deer, transgenic mice expressing cervid PrPC [Tg(cerPrP)1536 mice], and ferrets supported amplification. PMCA using normal Tg(cerPrP)1536 brains as the PrPC substrate produced >6.5 × 109-fold amplification after six rounds. Highly efficient in vitro amplification of PrPCWD is a significant step toward detection of PrPCWD in the body fluids or excreta of CWD-susceptible species.


2021 ◽  
Vol 22 (5) ◽  
pp. 2271
Author(s):  
Maria Immaculata Arifin ◽  
Samia Hannaoui ◽  
Sheng Chun Chang ◽  
Simrika Thapa ◽  
Hermann M. Schatzl ◽  
...  

Chronic wasting disease (CWD) is a prion disease found in both free-ranging and farmed cervids. Susceptibility of these animals to CWD is governed by various exogenous and endogenous factors. Past studies have demonstrated that polymorphisms within the prion protein (PrP) sequence itself affect an animal’s susceptibility to CWD. PrP polymorphisms can modulate CWD pathogenesis in two ways: the ability of the endogenous prion protein (PrPC) to convert into infectious prions (PrPSc) or it can give rise to novel prion strains. In vivo studies in susceptible cervids, complemented by studies in transgenic mice expressing the corresponding cervid PrP sequence, show that each polymorphism has distinct effects on both PrPC and PrPSc. It is not entirely clear how these polymorphisms are responsible for these effects, but in vitro studies suggest they play a role in modifying PrP epitopes crucial for PrPC to PrPSc conversion and determining PrPC stability. PrP polymorphisms are unique to one or two cervid species and most confer a certain degree of reduced susceptibility to CWD. However, to date, there are no reports of polymorphic cervid PrP alleles providing absolute resistance to CWD. Studies on polymorphisms have focused on those found in CWD-endemic areas, with the hope that understanding the role of an animal’s genetics in CWD can help to predict, contain, or prevent transmission of CWD.


Author(s):  
Mingxuan Ding ◽  
Kenta Teruya ◽  
Weiguanliu Zhang ◽  
Hae Weon Lee ◽  
Jue Yuan ◽  
...  

AbstractPrevious studies have revealed that the infectious scrapie isoform of prion protein (PrPSc) harbored in the skin tissue of patients or animals with prion diseases can be amplified and detected through the serial protein misfolding cyclic amplification (sPMCA) or real-time quaking-induced conversion (RT-QuIC) assays. These findings suggest that skin PrPSc-seeding activity may serve as a biomarker for the diagnosis of prion diseases; however, its utility as a biomarker for prion therapeutics remains largely unknown. Cellulose ethers (CEs, such as TC-5RW), widely used as food and pharmaceutical additives, have recently been shown to prolong the lifespan of prion-infected mice and hamsters. Here we report that in transgenic (Tg) mice expressing hamster cellular prion protein (PrPC) infected with the 263K prion, the prion-seeding activity becomes undetectable in the skin tissues of TC-5RW-treated Tg mice by both sPMCA and RT-QuIC assays, whereas such prion-seeding activity is readily detectable in the skin of untreated mice. Notably, TC-5RW exhibits an inhibitory effect on the in vitro amplification of PrPSc in both skin and brain tissues by sPMCA and RT-QuIC. Moreover, we reveal that TC-5RW is able to directly decrease protease-resistant PrPSc and inhibit the seeding activity of PrPSc from chronic wasting disease and various human prion diseases. Our results suggest that the level of prion-seeding activity in the skin may serve as a useful biomarker for assessing the therapeutic efficacy of compounds in a clinical trial of prion diseases and that TC-5RW may have the potential for the prevention/treatment of human prion diseases.


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.


2004 ◽  
Vol 78 (23) ◽  
pp. 13345-13350 ◽  
Author(s):  
Shawn R. Browning ◽  
Gary L. Mason ◽  
Tanya Seward ◽  
Mike Green ◽  
Gwyneth A. J. Eliason ◽  
...  

ABSTRACT We generated mice expressing cervid prion protein to produce a transgenic system simulating chronic wasting disease (CWD) in deer and elk. While normal mice were resistant to CWD, these transgenic mice uniformly developed signs of neurological dysfunction ∼230 days following intracerebral inoculation with four CWD isolates. Inoculated transgenic mice homozygous for the transgene array developed disease after ∼160 days. The brains of sick transgenic mice exhibited widespread spongiform degeneration and contained abnormal prion protein and abundant amyloid plaques, many of which were florid plaques. Transmission studies indicated that the same prion strain caused CWD in the analyzed mule deer and elk. These mice provide a new and reliable tool for detecting CWD prions.


2015 ◽  
Vol 89 (24) ◽  
pp. 12362-12373 ◽  
Author(s):  
Camilo Duque Velásquez ◽  
Chiye Kim ◽  
Allen Herbst ◽  
Nathalie Daude ◽  
Maria Carmen Garza ◽  
...  

ABSTRACTTransmission of chronic wasting disease (CWD) between cervids is influenced by the primary structure of the host cellular prion protein (PrPC). In white-tailed deer,PRNPalleles encode the polymorphisms Q95 G96 (wild type [wt]), Q95 S96 (referred to as the S96 allele), and H95 G96 (referred to as the H95 allele), which differentially impact CWD progression. We hypothesize that the transmission of CWD prions between deer expressing different allotypes of PrPCmodifies the contagious agent affecting disease spread. To evaluate the transmission properties of CWD prions derived experimentally from deer of fourPRNPgenotypes (wt/wt, S96/wt, H95/wt, or H95/S96), transgenic (tg) mice expressing the wt allele (tg33) or S96 allele (tg60) were challenged with these prion agents. Passage of deer CWD prions into tg33 mice resulted in 100% attack rates, with the CWD H95/S96 prions having significantly longer incubation periods. The disease signs and neuropathological and protease-resistant prion protein (PrP-res) profiles in infected tg33 mice were similar between groups, indicating that a prion strain (Wisc-1) common to all CWD inocula was amplified. In contrast, tg60 mice developed prion disease only when inoculated with the H95/wt and H95/S96 CWD allotypes. Serial passage in tg60 mice resulted in adaptation of a novel CWD strain (H95+) with distinct biological properties. Transmission of first-passage tg60CWD-H95+isolates into tg33 mice, however, elicited two prion disease presentations consistent with a mixture of strains associated with different PrP-res glycotypes. Our data indicate that H95-PRNPheterozygous deer accumulated two CWD strains whose emergence was dictated by the PrPCprimary structure of the recipient host. These findings suggest that CWD transmission between cervids expressing distinct PrPCmolecules results in the generation of novel CWD strains.IMPORTANCECWD prions are contagious among wild and captive cervids in North America and in South Korea. We present data linking the amino acid variant Q95H in white-tailed deer cellular prion protein (PrPC) to the emergence of a novel CWD strain (H95+). We show that, upon infection, deer expressing H95-PrPCmolecules accumulated a mixture of CWD strains that selectively propagated depending on thePRNPgenotype of the host in which they were passaged. Our study also demonstrates that mice expressing the deer S96-PRNPallele, previously shown to be resistant to various cervid prions, are susceptible to H95+CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD.


Author(s):  
Nicholas J. Haley ◽  
Juergen A. Richt

Since chronic wasting disease (CWD) was first identified nearly 50 years ago in a captive mule deer herd in the Rocky Mountains of the United States, it has slowly spread across North America through the natural and anthropogenic movement of cervids and their carcasses.  As the endemic areas have expanded, so has the need for rapid, sensitive, and cost effective diagnostic tests – especially those which take advantage of samples collected antemortem.  Over the past two decades, strategies have evolved from the recognition of microscopic spongiform pathology and associated immunohistochemical staining of the misfolded prion protein to enzyme-linked immunoassays capable of detecting the abnormal prion conformer in postmortem samples.  In a history that parallels the diagnosis of more conventional infectious agents, both qualitative and real-time amplification assays have recently been developed to detect minute quantities of misfolded prions in a range of biological and environmental samples.  With these more sensitive and semi-quantitative approaches has come a greater understanding of the pathogenesis and epidemiology of this disease in the native host.  Because the molecular pathogenesis of prion protein misfolding is broadly analogous to the misfolding of other pathogenic proteins, including Aβ and α-synuclein, efforts are currently underway to apply these in vitro amplification techniques towards the diagnosis of Alzheimer’s disease, Parkinson’s disease, and other proteinopathies.   Chronic wasting disease – once a rare disease of Colorado mule deer – now represents one of the few naturally occurring protein misfolding disorders which might allow continued development and implementation of novel diagnostic strategies in an animal model.


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