PLoS Pathog. 2024 Apr; 20(4): e1012175. Published online 2024 Apr 19. doi: 10.1371/journal.ppat.1012175
PMCID: PMC11062561 PMID: 38640117
Sensitive detection of pathological seeds of α-synuclein, tau and prion protein on solid surfaces
Christina D. Orrú, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing,corresponding author# 1 ,* Bradley R. Groveman, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – review & editing,# 1 Andrew G. Hughson, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – review & editing,# 1 Tomás Barrio, Data curation, Investigation, Methodology, Writing – review & editing, 2 Kachi Isiofia, Investigation, Methodology, Writing – review & editing, 1 , ¤a Brent Race, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – review & editing, 1 Natalia C. Ferreira, Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – review & editing, 1 , ¤b Pierluigi Gambetti, Funding acquisition, Resources, Writing – review & editing, 3 David A. Schneider, Funding acquisition, Resources, Writing – review & editing, 4 Kentaro Masujin, Resources, 5 Kohtaro Miyazawa, Funding acquisition, Resources, Writing – review & editing, 5 Bernardino Ghetti, Funding acquisition, Resources, Writing – review & editing, 6 Gianluigi Zanusso, Conceptualization, Resources, Writing – review & editing, 7 and Byron Caughey, Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editingcorresponding author 1 ,*
Abstract Prions or prion-like aggregates such as those composed of PrP, α-synuclein, and tau are key features of proteinopathies such as prion, Parkinson’s and Alzheimer’s diseases, respectively. Their presence on solid surfaces may be biohazardous under some circumstances. PrP prions bound to solids are detectable by ultrasensitive real-time quaking-induced conversion (RT-QuIC) assays if the solids can be immersed in assay wells or the prions transferred to pads. Here we show that prion-like seeds can remain detectable on steel wires for at least a year, or even after enzymatic cleaning and sterilization. We also show that contamination of larger objects with pathological seeds of α-synuclein, tau, and PrP can be detected by simply assaying a sampling medium that has been transiently applied to the surface. Human α-synuclein seeds in dementia with Lewy bodies brain tissue were detected by α-synuclein RT-QuIC after drying of tissue dilutions with concentrations as low as 10−6 onto stainless steel. Tau RT-QuIC detected tau seeding activity on steel exposed to Alzheimer’s disease brain tissue diluted as much as a billion fold. Prion RT-QuIC assays detected seeding activity on plates exposed to brain dilutions as extreme as 10−5–10−8 from prion-affected humans, sheep, cattle and cervids. Sampling medium collected from surgical instruments used in necropsies of sporadic Creutzfeldt-Jakob disease-infected transgenic mice was positive down to 10−6 dilution. Sensitivity for prion detection was not sacrificed by omitting the recombinant PrP substrate from the sampling medium during its application to a surface and subsequent storage as long as the substrate was added prior to performing the assay reaction. Our findings demonstrate practical prototypic surface RT-QuIC protocols for the highly sensitive detection of pathologic seeds of α-synuclein, tau, and PrP on solid objects.
summary
Prions and prion-like protein aggregates associated with neurodegenerative diseases such as Creutzfeldt-Jakob disease, Alzheimer’s disease, and dementia with Lewy bodies may persist in the environment or on medical instruments and in some cases be transmissible. Sensitive detection of these self-propagating aggregates, or seeds, on solid surfaces, machinery, tools, and surgical instruments might help prevent fomite-borne disease dissemination. Here we describe a novel RT-QuIC (sfRT-QuIC) to detect a variety of pathological brain-derived prion, α-synuclein, or tau seeds on stainless steel and acrylic surfaces. sfRT-QuIC testing showed that α-synuclein and tau seeds remained active on surgical forceps and scissors, even after routine instrument sterilization. Furthermore, we found that pathological protein seeds eluted from surfaces could be collected and stored for transport or delayed testing. sfRT-QuIC is a simple and effective, high throughput assay for sensitive detection of pathological protein seed contamination of common surfaces.
Introduction
Multiple neurodegenerative diseases involve the accumulation of aggregates of specific proteins, often in the form of self-propagating and sometimes transmissible cross-β amyloid fibrils [1–5]. The experimental transmissibility of several of these pathologic protein aggregates has raised concerns about potential natural or iatrogenic routes of transmission of such proteinopathies [3,6–8]. Such transmissions have been most thoroughly documented for the mammalian PrP-based prion diseases, including Creutzfeldt-Jakob disease (CJD) and GSS [9] in humans, chronic wasting disease (CWD) in cervids, scrapie in sheep and goats, and bovine spongiform encephalopathy (BSE) [10]. The molecular pathogenesis of PrP prion diseases is based on the conversion of the hosts’ normal monomeric prion protein (PrPC) into a refolded, aggregated, and infectious state (generically called PrPSc) in which, for the prion structures that have been solved to date, PrP molecules become stacked via parallel in-register intermolecular β-sheets (PIRIBS) into amyloid fibrils [11–13]. Relative to most pathogens, prions are unusually persistent in the environment [14–19] and more difficult to inactivate (e.g. [20,21]). Exposure to contaminated surgical instruments has initiated fatal human prion disease cases [22–24]. Scrapie and CWD have been transmitted via contamination of environmental surfaces (e.g., [15,25,26]). Another type of prion, i.e., the α-synuclein (α-syn)-based prions of multiple system atrophy (MSA), have been experimentally transmitted via suture wires exposed to human MSA brain homogenate [8]. The assessment and minimization of risks of iatrogenic or environmentally mediated proteinopathy transmission would be aided by the availability of practical methods for detecting contamination of various surfaces with prion or prion-like protein aggregates.
The development of prion seed amplification assays (SAAs) [27–29] has enabled the ultrasensitive detection of various types of prions and prion-like protein aggregates of PrP, α-syn, tau, and Aβ to the attogram to low femtogram range [29–32]. In current real-time quaking-induced conversion (RT-QuIC) SAAs, self-propagating protein aggregates are detected based on their ability to seed the conversion of recombinant PrP, α-Syn or tau monomers into amyloid fibrils that can then be detected using an amyloid-sensitive fluorescent dye, thioflavin T (ThT) [29]. RT-QuIC assays have been designed for high throughput analysis in 96 or 384-well plates and can provide rough quantitation through end-point titration analysis [29] or, under more carefully controlled conditions, comparison of reaction kinetics at single dilutions [33,34]. SAAs can detect PrP prion seeds bound to solid surfaces such as steel wires when the material is small enough to be added to the reaction microtube or well [18,35–39]. However, a limitation of most existing assays is the inability to detect prions that are bound to materials that interfere with the assay or will not fit into an assay well. Two recent studies reported detection of CWD prions from flat surfaces by sampling with foam swabs that are sonicated to elute prion seeds that are then concentrated and analyzed by RT-QuIC and PMCA [19,40]. Here, we demonstrate a more direct approach for detecting a broad range of pathologic PrP, α-Syn and tau prions or prion-like aggregates on large surfaces by simply exposing a sampling media to a surface (e.g., a surgical instrument) and then transferring the solution into an RT-QuIC assay plate for analysis. These prototypic surface RT-QuIC (sfRT-QuIC) assays provide methods for assessing contamination of medical instruments or other solid fomites that may be sources of proteinopathy infections in clinical, agricultural, and wildlife settings.
Results sfRT-QuIC detection of 263K prion seeds 1 year after contamination on stainless steel Although we and others have previously detected prion seeding activity on stainless steel wires using SAAs such as RT-QuIC [35], we first sought evidence of whether seeding activity can persist long term on stainless steel. We dipped steel wires into a 10−3 (w/v) dilution of brain tissue (homogenized) from a hamster infected with the 263K scrapie strain, rinsed them in water, and stored them for 1 y prior to RT-QuIC testing in comparison to freshly contaminated wires. For testing, the wires were added directly to wells of an RT-QuIC test plate and left there for the duration of the assay reaction. Strong positive RT-QuIC responses were obtained in both the freshly exposed and 1 y samples, but not with wires exposed to uninfected hamster brain homogenate (Fig 1). Slightly slower reaction kinetics were observed in the 1 y sample suggesting that long terms storage may result in a modest reduction of seeding activity.
Detecting prion seeds dried onto flat stainless-steel or acrylic surfaces We then tested if prion contamination can be detected on larger flat steel or acrylic surfaces by transiently exposing them to RT-QuIC sampling medium (SM: RT-QuIC reaction mix; see methods and Fig 2A). In pilot experiments (Fig 3A), 4 aliquots of 263K or normal hamster brain homogenates (2 μL of 10−4 solid brain tissue equivalent dilution) were spotted onto stainless steel plates or acrylic sheets and allowed to air dry 16–24 h in a biosafety hood with active laminar flow. Sampling medium (100 μl) was delivered as a bead of liquid over each spot and allowed to sit for 5 min at room temperature. The SM was pipetted up and down 3 times and ~95 μl was recovered, transferred to the well of a 96-well plate, and subjected to the remainder of the RT-QuIC protocol as above. Tests of all 4 replicate collections of the scrapie brain on either stainless-steel (Fig 3A) or acrylic (Fig 3B) were positive in the RT-QuIC assay, while those of the uninfected brain were negative. Similar results were obtained from a larger-volume protocol in which two 40 μl spots of 10−3 dilutions of 263K, deer CWD, or elk CWD brain homogenates were placed within a ~ 3 cm circle on stainless-steel (Fig 3C,3E and 3F) or acrylic (Fig 3D) and sampled with 2 ml SM (Fig 3C–3F
Detection of disease-associated α-Syn, tau, and prion seeds spotted on stainless steel surfaces: sfRT-QuIC Based on these initial findings, we further investigated the ability of this overall assay strategy, which we will call surface RT-QuIC, or sfRT-QuIC, to detect contamination of pathological seeds of α-Syn, tau, and PrP on stainless-steel surfaces (Fig 2). For the α-Syn and tau seed experiments, we used brain homogenates from patients with neuropathologically confirmed diagnoses of dementia with Lewy Bodies (DLB) or sporadic Alzheimer’s disease (sAD), respectively. Two μL of serial 10-fold dilutions of the brain homogenates were spotted onto stainless steel plates and allowed to air dry 16–24 h (Fig 2A). A bead of SM (100 μl) was applied to each spot and allowed to sit for 5 min. The SM was pipetted up and down 3 times and ~95 or 48 μl was recovered, transferred to a well of a 96- or 384-well plate, respectively (the latter for tau detection), and subjected to one of three of our previously described RT-QuIC protocols for either α-Syn, tau, or PrP seeds. We compared our sfRT-QuIC results to those obtained from standard solution RT-QuIC assays in which the same homogenates were pipetted directly into the reaction wells (Fig 4). Comparable end-point dilutions were obtained with both the solution and surface versions of the α-synuclein and tau RT-QuIC assays when seeded with DLB (Fig 4A and 4B) or sAD (Fig 4C and 4D) brain homogenates, respectively. Specifically, at least one positive in four replicate assay wells were obtained in both assay protocols with tissue dilutions of 10−4–10−6 (DLB) and 10−6–10−9 (sAD). Similar estimates of the measured seed concentrations (log 50% seeding dose, or log SD50, per mg original tissue) were obtained by application of the Spearman-Kärber algorithm [41]. In contrast, in negative control assays, no α-syn seeding activity was detected in either solution RT-QuIC or sfRT-QuIC using a negative control, non-synucleinopathy, brain homogenate from a patient with a primary tauopathy (cortico-basal degeneration) at 10−4 dilution (Fig 4A). Also, no tau seeding activity was detected in brain homogenate from a completely tau-free knockout (KO) mouse at 10−3 dilution (Fig 4C and 4D). However, we detected some tau seeding activity in tau sfRT-QuIC using the highest (10−3) concentration (only) of human brain homogenate from a patient with cerebrovascular disease (CVD), but without any known tauopathy (Fig 4D). This was not surprising because we have often detected low levels of tau seeding activity in brain tissue from CVD cases and multiple other types of cases without primary tauopathy [42–44], albeit at concentrations several orders of magnitude lower than those found in sAD brain, as seen here as well (Fig 4D).
To assess the sensitivity of sfRT-QuIC with a variety of PrP prion strains, end-point dilution analyses were performed on brain homogenates (Fig 2A) from cases of human sporadic (s) CJD (MM1 subtype), genetic (g) CJD (E200K mutant), Gerstmann-Sträussler-Scheinker disease (GSS; P102L mutant); ovine classical scrapie (ARQ/ARQ PrP genotype), and deer CWD (Fig 5). Although sfRT-QuIC sensitivities for GSS, CWD and scrapie brain samples were lower compared to the solution-based RT-QuIC, they differed by less than 10-fold (Fig 5C). Whereas these various prion-infected brain tissues gave positive sfRT-QuIC assays out to dilutions of 10−5 to 10−8, depending upon strain, negative control (uninfected) brain tissues were negative at 10−4. Altogether, these results indicated that sfRT-QuIC is nearly as sensitive as direct solution RT-QuIC in detecting a variety of prion strains in brain homogenates.
To quantify the recovery of prion seeding activity from a surface (Fig 2B), SM was applied to 2 μL of 10% human sCJD brain homogenate spots dried overnight onto stainless steel and end-point dilutions of the respective SMs were performed. No positive reactions were obtained using uninfected control brain homogenates. Neat sCJD SM were also negative presumably because, as previously observed, excessive brain tissue matrix can inhibit RT-QuIC assays [45]. However, positive reactions were obtained from further dilutions out to 10−6 (Fig 6A–6B), which, when considered in terms of the brain equivalents delivered to the stainless steel, corresponded to recoveries of a majority of the seeding activity initially applied to the stainless-steel. Assays were also done with other prion-infected brain homogenates assayed out to 10−4, namely human variant CJD, fatal familial insomnia D178N, gCJD E200K, and GSS P102L; deer CWD; sheep scrapie; bovine classical C-BSE, and atypical H- and L-types of BSE) (Fig 6C). For all but the C-BSE and CWD samples, which were known to have low seeding activity, each of these dilutions were RT-QuIC-positive in all quadruplicate wells. Thus, even after drying of brain homogenates onto stainless-steel surfaces overnight, substantial proportions of prion seeding activity can be recovered in a simple SM elution step.
Prion detection on surgically contaminated necropsy instruments We then tested sfRT-QuIC in a more clinically relevant scenario. We used surgical instruments (forceps and scissors) that had been used to cut brain tissue from sCJD-infected transgenic mice expressing only human PrP (Tg66) [46], dry wiped with gauze (n = 2) or not (n = 3), and then air-dried prior to the application of SM (Fig 2C). For three of the instruments, including a wiped scissor, SM dilutions of 10−2–10−5 were positive in all quadruplicate wells, while SMs from the other two instruments were uniformly positive out to 10−3 and 10−4 dilutions (Fig 7). In contrast, no sfRT-QuIC positivity was seen on instruments used to dissect uninfected Tg66 mice brain tissue (Fig 7). These findings indicated that multiple logs of prion seeding activity can be detected on surgical instruments that had been used during necropsy of sCJD infected animals.
Effects of post-sampling SM storage and omission of recombinant PrP in SM In the experiments described so far, we included recombinant PrPSen in the SM. However, to simplify the SM and make it more compatible with storage and shipping before and after sampling but prior to RT-QuIC analysis (e.g., to allow transfer to a centralized assay facility), we also tested collections using SM without recombinant PrPSen and various storage conditions of the SM. 10% sCJD, CWD, and classical scrapie brain homogenates (2 μl) were applied to stainless steel, allowed to dry, and exposed to SM that either contained or lacked recombinant PrPSen (S1 Fig). SM lacking recombinant PrPSen included the final concentration of SDS that would have otherwise come from the seed diluent. We then stored the SMs for 0–7 d at 4°C, or 7 d at -20°C. We then thawed the samples, and added recombinant PrPSen to the SMs that initially lacked it, and performed end-point dilution RT-QuIC analysis of the SMs. The estimated seed concentrations (log SD50/mg original brain equivalent) recovered in the SMs were within a log of each other regardless of the presence or absence of recombinant PrP, or the storage time prior to RT-QuIC (S1 Fig A). Occasionally a positive replicate well was observed in the negative control samples, most notably with the uninfected cervid brain (S1 Fig B); however, as described in the methods these sporadic apparent false-positive wells were unrelated to the storage conditions and did not change the outcome of the assay as these samples did not meet criteria to be considered positive. Our results show that sensitive surface detection can be achieved using SM that does not contain recombinant PrPSen and that SM can be stored under a variety of conditions prior to adding the recombinant PrPSen for delayed RT-QuIC testing.
Effect of pre-rinsing on detection of sAD, DLB, and sCJD-associated seeds on stainless-steel surface We then tested effects of a water wash on detection of seeds from brain homogenates dried onto stainless steel (S2 Fig). In all cases, water prewash had little effect on the seed concentrations recovered in SM aliquots applied to the dried spots. Overall, our results showed that single transient water rinse did little to reduce the levels of α-syn, tau or prion seed contamination in brain homogenate dried onto stainless-steel.
Effect of standard sterilization treatment of stainless-steel wires on sAD, DLB and Parkinson’s disease (PD)-associated seeds Iatrogenic transmission of human prion diseases is well documented [22] and has led to the implementation of precautions and extreme decontamination protocols when, for example, surgical procedures have been performed on suspected CJD patients [6,24]. However, if prion disease is not suspected, reusable surgical instruments are typically subjected to a milder decontamination process that includes: 1) wiping/rinsing to minimize tissue debris, 2) treatments with disinfectant and/or enzymes (e.g., Medline Enzymatic Surgical Instrument Detergent and Presoak tested below), 3) rinsing with water and 4) sterilization by autoclaving (e.g.: 270°F/132°F for 5 min under pre-vacuum). To test if such a decontamination protocol would eliminate surface-bound α-syn or tau seeding activity, we assayed stainless steel wires contaminated with brain homogenate from patients with DLB or PD with α-syn RT-QuICR or sAD with the K12 Tau RT-QuIC (Fig 8). We detected wire-bound DLB- and PD-associated seeding activity even after the decontamination protocol described in Methods. While all reactions with the wires subjected to the decontamination protocol still showed positive seeding activity, slower reaction kinetics suggests a moderate reduction in seeding activity. We observed a similar phenomenon, albeit with more variable amplification kinetics, when testing Alzheimer’s disease contaminated stainless steel wires by K12 Tau RT-QuIC (Fig 8). We note that because the wires could not be fully submerged in reaction mix in 384 well plates, (with which the K12 assay was developed), we used 96 well plates for these experiments. It is possible that this atypical set-up led to sub-optimal sensitivity. Nevertheless, our results provide evidence that, as is known to be the case for PrP prions [47–49], standard cleaning and sterilization protocols may not inactivate proteopathic seeds bound to stainless-steel.
Discussion
Persistent prion contamination of surfaces is a well-demonstrated risk in environmental, medical and wildlife settings. More recently, evidence of experimental transmission of some types of disease-associated α-synuclein, tau and β-amyloid seeds [6,50–55] have prompted concerns about surface contamination by these types of seeds as well. sfRT-QuIC provides a new method of detecting certain pathological protein seeds on surfaces that are too large to immerse in an RT-QuIC reaction well. In the case of prion sfRT-QuIC at least, SM that has been exposed test surfaces can be stored for at least a week at -20°C before RT-QuIC analysis. The ability to use SM without rPrPSen substrates should minimize the chances of false-positive assays due to spontaneous nucleation. This feature may make sfRT-QuIC testing more robust and accessible to those who lack on site testing capabilities.
Quantitative comparison of sfRT-QuIC assays to our standard solution RT-QuIC assays showed that not all of the seeding activity that was initially deposited on solid surfaces was detected by sfRT-QuIC, but the difference was less than ~0.8 log. This loss is not surprising and is likely due to some combination of an inability of transient SM exposure to recover bound seeds and inefficiency of permanently bound seeds in inducing nascent fibrilization of the substrate monomers while exposed transiently to SM (when the SM contains the RT-QuIC substrate). However, even if sfRT-QuIC detection of seeds in dried deposits is not quite as sensitive as solution RT-QuIC analysis of the corresponding initial brain homogenate, it still can provide highly sensitive detection of proteopathic seed contamination of solid surfaces.
Effective prion decontamination of non-disposable surgical instruments can be important to avoid iatrogenic transmission of human and possibly animal prions. In a recent study [56], Hervé et al reported that, despite the implementation of national guidelines to address prion contamination concerns in the UK, microscopic levels of proteins, which could include prions, remain on many reprocessed instruments after sterilization. As we have shown by testing humanized mouse prion contaminated surgical tools, sfRT-QuIC has the potential of being used to screen such surgical instruments for the presence of prion seeds. Furthermore, we have shown that α-syn and tau seeding activity can survive a commonly-used decontamination procedure for surgical instruments. Previous studies have also similarly reported that synuclein, tau and amyloid-beta can be difficult to remove from steel wires [57–59]. Interestingly, each of these proteins appear to have their own specific sensitivities to different, more aggressive types of inactivation.
The epidemiological risks of iatrogenic transmission of synucleinopathies, tauopathies, and β-amyloidoses appear to be low and remain under investigation and debate. However, some lines of evidence suggest that such transmissions can occur, albeit very rarely via invasive procedures [55,60–62]. The ability to sensitively monitor potentially infectious pathologic seeds on the surfaces of surgical instruments and medical devices such as endoscopes as reported here and by Yuan et al [19] should be helpful in assessing and mitigating such risks.
In this study we mainly focused on sfRT-QuIC detection on large smooth surfaces such as stainless steel or acrylic, which may be found in hospital or butchering and food processing settings. More uneven and porous surfaces such as wood or concrete have been shown to retain prions more tenaciously [26]. Further testing is required to discern the utility of sfRT-QuIC in those scenarios.
The studies by Yuan et al [18,19] have described a complementary RT-QuIC-based prion surface detection assay to ours for CWD and rodent prion strains. Another recent study described a PMCA- and swabbing-based method for detecting CWD prions on naturally exposed surfaces [40]. Here, we have extended the surface RT-detection approach to a wider variety of human and animal prion strains, as well as to pathologic seeds associated with α-synucleinopathies and tauopathies. While our respective assays show similar sensitivities, sfRT-QuIC provides a simpler protocol that does not require swabbing, sonication, or vacuum concentration steps. Also, in contrast to the Yuan protocol, the SM in sfRT-QuIC is not proteinase K-digested, which suggests that the sfRT-QuIC might be better suited to the detections of both protease-sensitive and resistant forms of prions or other types of seeds. With these improvements, sfRT-QuIC provides a simple and effective, high throughput method for sensitive detection of proteopathic seed contamination on common surfaces. The easy and cost-effective seed collection protocol paired with the compatibility with storing and shipping SM samples to RT-QuIC capable facilities around the world should facilitate its implementation.
Our current study presents an initial panel of prototypic sfRT-QuIC seed amplification assays. However, given the plethora of diseases that are now understood to involve the accumulation of various types of self-propagating amyloid fibrils [3, 5, 63–66] it will be important to expand the panels of sfRT-QuIC assays to the many proteopathic aggregates that may contaminate solid surfaces under certain circumstances.
Go to: Materials and methods Ethics statement snip...end...see full text;
''sfRT-QuIC testing showed that α-synuclein and tau seeds remained active on surgical forceps and scissors, even after routine instrument sterilization.''
This old study by Gibbs et Al should have been a wake up call back in 1994…terry
1: J Neurol Neurosurg Psychiatry 1994 Jun;57(6):757-8
Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8006664&dopt=Abstract
Direct neural transmission of vCJD/BSE in macaque after finger incision
In conclusion, we have observed that the exposure of a primate to vCJD/BSE through a distal finger lesion induces, after more than 7.5 years of silent incubation, a massive deposit of PrPd , strictly restricted to the nervous system and the eye.
Our data suggest a new type of pure unique peripheral nervous contamination in which the Scs would have a major role in the mode of centripetal progression of PrPd in the peripheral nervous system. Moreover, considering the fact that, recently, “a variant CJD diagnosed 7.5 years after occupational exposure” (cryomicrotomy) in a technician was observed [5], this experimental case report supports the risk linked to professional exposure and reinforces the necessity of adequate measures of prevention.
Second death in France in a laboratory working on prions
Creutzfeldt-Jakob disease has killed a person who handled this infectious agent at Inrae in Toulouse. After a first death in 2019, a moratorium on work on this pathogen has been extended.
Temporary suspension of work on prions in French public research laboratories
France issues moratorium on prion research after fatal brain disease strikes two lab workers
By Barbara CasassusJul. 28, 2021 , 4:35 AM
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Variant Creutzfeldt–Jakob disease was identified in a technician who had cut her thumb while handling brain sections of mice infected with adapted BSE 7.5 years earlier. The long incubation period was similar to that of the transfusion-transmitted form of the disease.
February 14, 2001
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Terry S. Singeltary, Sr
Author Affiliations
JAMA. 2001;285(6):733-734. doi:10-1001/pubs.JAMA-ISSN-0098-7484-285-6-jlt0214
To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
26 MARCH 2003
RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Terry S. Singeltary, retired (medically)
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?
FRIDAY, MAY 03, 2024
National Prion Disease Pathology Surveillance Center Cases Examined1 April 8th 2024
I'm thinking iatrogenic CWD transmission to humans, what if?
SATURDAY, APRIL 20, 2024
Chronic Wasting Disease CWD TSE Prion of Cervid Zoonosis to humans, iatrogenic transmission, what if 2024?
Monday, February 26, 2024
iatrogenic Prion Mechanism Diseases, or iTSE Prion Diseases, what if?
Professor John Collinge on tackling prion diseases sCJD accounts for around 1 in 5000 deaths worldwide
“The best-known human prion disease is sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia which accounts for around 1 in 5000 deaths worldwide.”
Professor John Collinge on tackling prion diseases
Professor John Collinge is Director of the MRC Prion Unit and also directs the NHS National Prion Clinic at the adjacent National Hospital for Neurology and Neurosurgery.
John Collinge What are prions, why are they important, and how might they help us develop treatments for neurodegenerative conditions like dementia?
Prions are lethal pathogens that cause neurodegenerative diseases of humans and other mammals.
The best-known human prion disease is sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia which accounts for around 1 in 5000 deaths worldwide. In sharp distinction to all other infectious agents, prions lack their own DNA or RNA genome and consist of polymers of a misfolded form of a normal cellular protein (the prion protein or PrP) which form amyloid fibrils.
These fibres grow by addition of PrP molecules at their ends and they eventually fragment producing more prion particles which continue this process and spread throughout the brain. The final proof of the once controversial “protein-only hypothesis” of prions came with the determination of the structure of infectious prions at near atomic resolution by cryogenic electron microscopy by ourselves and US colleagues in the last few years.
The normal cellular prion proteins are very similar between different species of mammals and therefore a prion infection from one species can sometimes infect another species. This is what happened with the prion disease of cattle, bovine spongiform encephalopathy (BSE) in the 1990’s which caused a new human prion disease known as variant Creutzfeldt-Jakob disease (vCJD) and led to the BSE crisis in the UK, EU and other countries.
While human prion diseases are thankfully rare, there are common prion diseases of other species, for example scrapie in sheep and goats worldwide and chronic wasting disease in deer in North America. While prions were first thought to be unique to these rare neurological diseases, it became clear that the molecular process was of far wider relevance with for example the recognition of several different proteins in yeast that could form prions.
Most importantly with respect to neurodegeneration and dementia in humans, it has been established that similar so-called “prion-like” mechanisms are involved in much commoner conditions including Alzheimer’s and Parkinson’s diseases. In Alzheimer’s disease (AD) for example, two proteins in the brain, amyloid-beta and tau can form self-propagating assemblies which spread in the brain. Indeed, we reported in two articles in Nature that the amyloid-beta pathology seen in AD can be transmissible between humans in rare circumstances causing the newly recognised condition iatrogenic cerebral amyloid angiopathy.
There is accumulating evidence also for iatrogenic AD. Understanding prion biology, and in particular how propagation of prions leads to neurodegeneration, is therefore of central research importance in medicine. Many years ago, we demonstrated that targeting the production of the normal cellular prion protein completely halted the progression of neurodegeneration (and indeed even reversed early pathological changes) in laboratory mice. This work has underpinned multiple efforts to develop rational treatments for prion and other neurodegenerative diseases.
What first attracted you to the area of prion diseases?
I first became involved in this field while working as a graduate student applying early molecular genetic methods to study neuropsychiatric diseases and was involved in the first description of mutations in the prion protein gene in the late 1980s in what are now known as the inherited prion diseases.
As it was already known that brain tissue from patients who died from some of these genetic conditions could transmit disease when inoculated into laboratory animals, it seemed to me highly likely that some version of the then intensely controversial “protein-only hypothesis” was likely to be correct: this had major implications in pathobiology.
I went on to show that being heterozygous for a common human prion protein polymorphism had a profound effect on susceptibility to CJD; I considered this entirely consistent with a protein-only agent and this led to further work studying the genetics of prion disease.
It seemed to me at the time that these early genetic insights, albeit in a rare disease, provided a powerful way in to study the fundamental basis of neurodegeneration. Of course, the evolving concerns about BSE in the early 1990’s also focussed my mind on the specific public and animal health risks posed by prions.
You led the UK’s first clinical trial in CJD, the largest yet conducted internationally. Can you tell us about this?
I was asked in 1997 by Medical Research Council (MRC) at the request of UK Government to establish and lead an MRC Unit to focus on understanding prion diseases and to ultimately develop treatments for them.
At the time it was unknown how many people would develop vCJD following the widespread dietary exposure of the UK population to BSE prions and the possibility that this may eventually affect hundreds of thousands could not then be excluded.
An early proposal (by Dr Prusiner at UCSF) for a treatment for CJD was the anti-malarial drug quinacrine based on early work in prion-infected cell cultures. We were asked by the Chief Medical Officer to establish a clinical trial and did so in collaboration with the MRC Clinical Trials Unit also based at UCL.
While the MRC PRION-1 trial, as is was called, did not show any benefit of quinacrine, we did learn a great deal about how best to conduct a clinical trial in CJD in conjunction with patients and families affected by these terrible conditions.
This lead on to the formation of the National Prion Monitoring Cohort (NPMC) to study the natural history of prion diseases and to develop better clinical scales and biomarkers, and earlier diagnosis, to facilitate future clinical trials. In particular, we reasoned that having a large longitudinal data set would allow us to conduct adequately powered efficacy trials by comparison of treated patients with historical controls rather that using a more classical placebo-controlled study which was understandably unacceptable to patients and their families given the rapid and invariably fatal progression of these diseases.
The NPMC has been extremely successful with the strong support of the patient community and has recruited over 1100 patients to date, by far the largest dataset worldwide, and has enabled development and validation of multiple clinical scales and blood and CSF biomarkers.
What in your opinion have been some of the most important findings of your research to date?
Our early work established and characterised the inherited prion diseases and genetic susceptibility to acquired and sporadic prion disease, and pioneered diagnostic and presymptomatic genetic testing of neurodegenerative disease.
Many further genetic advances followed. Prions exist in multiple strain types and we developed molecular strain typing of prions which we applied in 1996 to first demonstrate that vCJD was caused by the same prion strain as cattle BSE, a finding of critical public and animal health significance at the time.
We characterised the pathogenesis of vCJD to inform public health risk assessments, developed the first blood test for vCJD and effective means to prion sterilise surgical instruments. We proposed the now widely accepted “conformational selection hypothesis” to explain the relationship between prion strains and intermammalian transmission barriers and proposed that prion strains constitute a “cloud” under host selection rather than a molecular clone.
Importantly, we described subclinical prion infections in which animals lived a normal lifespan despite harbouring high levels of prions and went on to study the kinetics of prion propagation in vivo and showed that propagation and neurotoxicity occur in two distinct mechanistic phases with pathology only developing after prion levels had plateaued in the brain.
We subsequently confirmed that prions themselves are not directly neurotoxic. These insights may be fundamental to understanding other diseases involving propagation and spread of assemblies of misfolded proteins, notably amyloid-beta and tau in AD.
Our discovery of human transmission of amyloid-beta pathology, mentioned above, in individuals treated many years earlier in childhood with human cadaver-derived pituitary growth hormone (c-hGH) accidentally contaminated with amyloid-beta seeds (prions) has wide implications for understanding, preventing and treating neurodegenerative diseases.
We defined iatrogenic cerebral amyloid angiopathy as a new disease, with relevance to Alzheimer’s disease and public health. Iatrogenic AD is likely to be recognised in the cohort of c-hGH recipients as they age further. Our demonstration that reducing prion expression during neuroinvasive prion disease in laboratory mice prevented onset, and reverses early pathology, produced a proof of principle of therapeutically targeting prion protein.
This led to our development of a biopharmaceutical which we have used to treat CJD. Recently, we have described the elusive structural basis of prion strain diversity: how prions can encode information in a non-Mendelian manner by determination of near atomic resolution structures of multiple prion stains by cryogenic electron microscopy.
In addition, we are proud of our long term field studies on the epidemic human prion disease kuru in the Eastern Highlands of Province of Papua New Guinea (PNG), in collaboration with the PNG Institute for Medical Research and the affected communities, which led to major insights including establishing the range of possible incubation periods of human prion infections (documenting cases with incubations over 50 years) and discovery of a novel prion protein variant selected by the epidemic which we demonstrated provides complete protection against prion infection and disease and the molecular structural basis of which we have recently characterised.
To what extent do you think we are entering a new era when it comes to developing drugs that could be used to prevent, or even reverse, neurodegenerative diseases?
Thankfully we are entering a time when disease-modifying treatments for neurodegenerative diseases are becoming feasible and indeed first-generation agents have arrived, but we cannot yet prevent, halt or reverse neurodegeneration.
Our own work validating cellular prion protein as a therapeutic target led us to develop a humanised monoclonal antibody with high affinity for cellular PrP and this has been used to treat six patients with CJD at UCLH. We consider the encouraging results justify a formal clinical trial and are seeking funding support for this at present.
Our therapeutic strategy has been to target normal cellular PrP itself, the substrate for prion propagation, and not the disease-related assemblies of misfolded PrP that accumulate during disease. We reasoned, given the diversity of these species, that drugs binding prions themselves would lead to the rapid development of resistance and indeed this has been shown to be the case with drugs developed elsewhere.
There may be important lessons here for other neurodegenerative diseases. For example, this may be critical in determining whether monoclonal antibody drugs targeting amyloid-beta fibrils or other assemblies, which also exist as structural polymorphs, have a sustained therapeutic effect or result in strain selection and evolution of resistant sub-strains as in prion diseases.
A number of pharmaceutical and biotech companies are however developing gene targeting methods, conceptually analogous to those we demonstrated many years ago block prion pathogenesis, to reduce expression of proteins implicated in various neurodegenerative diseases. Given the complexity and diversity of AD, in which multiple proteinopathies are involved, it is likely that effective treatments are going to require a cocktail of drugs hitting multiple targets.
Another key consideration is the importance of accurate diagnosis and early treatment, not only for the obvious need to intervene before irreversible brain cell loss has occurred, but because at the stage where significant cell death (with release of toxic materials) is occurring, these secondary non-specific neurodegenerative processes may dominate and be unresponsive to the specific targeted therapies. The ultimate aim must be to identify these pathogenic processes very early (ideally pre-clinically) and intervene to delay, and eventually prevent, clinical progression or onset.
Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
>>> The only tenable public line will be that "more research is required’’ <<<
>>> possibility on a transmissible prion remains open<<<
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?
Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
Nature 525, 247?250 (10 September 2015) doi:10.1038/nature15369 Received 26 April 2015 Accepted 14 August 2015 Published online 09 September 2015 Updated online 11 September 2015 Erratum (October, 2015)
snip...see full Singeltary Nature comment here;
Alzheimer's disease
let's not forget the elephant in the room. curing Alzheimer's would be a great and wonderful thing, but for starters, why not start with the obvious, lets prove the cause or causes, and then start to stop that. think iatrogenic, friendly fire, or the pass it forward mode of transmission. think medical, surgical, dental, tissue, blood, related transmission. think transmissible spongiform encephalopathy aka tse prion disease aka mad cow type disease...
Commentary: Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Posted by flounder on 05 Nov 2014 at 21:27 GMT
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Background
Alzheimer’s disease and Transmissible Spongiform Encephalopathy disease have both been around a long time, and was discovered in or around the same time frame, early 1900’s. Both diseases are incurable and debilitating brain disease, that are in the end, 100% fatal, with the incubation/clinical period of the Alzheimer’s disease being longer (most of the time) than the TSE prion disease. Symptoms are very similar, and pathology is very similar.
Methods
Through years of research, as a layperson, of peer review journals, transmission studies, and observations of loved ones and friends that have died from both Alzheimer’s and the TSE prion disease i.e. Heidenhain Variant Creutzfelt Jakob Disease CJD.
Results
I propose that Alzheimer’s is a TSE disease of low dose, slow, and long incubation disease, and that Alzheimer’s is Transmissible, and is a threat to the public via the many Iatrogenic routes and sources. It was said long ago that the only thing that disputes this, is Alzheimer’s disease transmissibility, or the lack of. The likelihood of many victims of Alzheimer’s disease from the many different Iatrogenic routes and modes of transmission as with the TSE prion disease.
Conclusions
There should be a Global Congressional Science round table event set up immediately to address these concerns from the many potential routes and sources of the TSE prion disease, including Alzheimer’s disease, and a emergency global doctrine put into effect to help combat the spread of Alzheimer’s disease via the medical, surgical, dental, tissue, and blood arena’s. All human and animal TSE prion disease, including Alzheimer’s should be made reportable in every state, and Internationally, WITH NO age restrictions. Until a proven method of decontamination and autoclaving is proven, and put forth in use universally, in all hospitals and medical, surgical arena’s, or the TSE prion agent will continue to spread. IF we wait until science and corporate politicians wait until politics lets science _prove_ this once and for all, and set forth regulations there from, we will all be exposed to the TSE Prion agents, if that has not happened already.
end...tss
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Posted by flounder on 05 Nov 2014 at 21:27 GMT
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Posted by flounder on 05 Nov 2014 at 21:27 GMT
http://journals.plos.org/plosone/article/comments?id=10.1371/journal.pone.0111492
Singeltary 2001
Subject: CJD or Alzheimer's or the same ???
Date: Sun, 29 Apr 2001 12:45:28 -0700
From: "Terry S. Singeltary Sr." Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@uni-karlsruhe.de
Bovine Spongiform Encephalopathy
Greetings List,
thought some might be interested in this. I have always wondered if CJD and or all TSEs and Alzheimer's could be linked. i have been of the opinion that Alzheimer's is a TSE for a long time, just at the low end of the titre of infectivity scale. i also believe in the accumulation theory. by dose, you could be killed by one sitting, or one injection, or one whatever, depending on the titre of infectivity of that whatever. on the other hand, if the dose is not a lethal dose, over a period of time, the accumulation will become lethal (if consumption continued), and i believe the route/source/titre of infectivity, will be a key roll to the incubation period, and symptoms.
just my opinion...snip…end…TSS
Biochem Biophys Rep. 2023 Jul; 34: 101446.
Published online 2023 Mar 3. doi: 10.1016/j.bbrep.2023.101446
PMCID: PMC10009011
PMID: 36923008
Autoclave treatment fails to completely inactivate DLB alpha-synuclein seeding activity
Jung-Youn Han,a,1 Kyung-Je Park,b,1 Hoo-Chang Park,b Yu-Ran Lee,b Roger A. Moore,c Hyun-Joo Sohn,b,∗∗ and Young Pyo Choia,∗
Abstract
Synucleinopathies are characterized by the deposition of alpha-synuclein (α-syn) aggregates in brain tissue. Pathological α-syn aggregates propagate in a prion-like manner and display prion-like biochemical properties. Using RT-QuIC, we measured α-syn seeding activity from brains of Dementia with Lewy body (DLB) patients post autoclave. Here, we show that autoclaving at 121 °C removes one to two log10 of α-syn seeding activity but the remaining 50% seeding dose (SD50) is more than 107/mg tissue. DLB brain samples autoclaved at 132 °C still revealed an SD50 of approximately 106/mg tissue. Our data suggest that DLB α-syn seeds are incompletely inactivated by standard autoclave, thus highlighting the need for evaluating laboratory procedures that fully inactivate them.
Keywords: Alpha-synuclein, Seeds, Inactivation, Autoclave, RT-QuIC, Prion
snip...
***> Our data suggest that DLB α-syn seeds are incompletely inactivated by standard autoclave, thus highlighting the need for evaluating laboratory procedures that fully inactivate them.
Saturday, March 18, 2023
Autoclave treatment fails to completely inactivate DLB alpha-synuclein seeding activity
12 January 2023
UCLan dentistry research directly links infected teeth and Alzheimer's Disease
This is the first study to link both root canal infections and gum disease directly to Alzheimer’s
A new study by researchers at the University of Central Lancashire (UCLan)’s School of Dentistry has revealed that Alzheimer’s disease may potentially be spread from infected teeth via dental procedures.
Conclusion:
This study detected both soluble and insoluble Aβ fibrils within the EPS of periodontal and endodontic natural biofilm, strongly suggesting its role as an antimicrobial peptide in combatting local infection, with potential risk for cross-seeding into the brain for AD development.
Wednesday, September 7, 2022
Multiple system atrophy MSA, Prion, TSE, iatrogenic, What If? ANOTHER CRITICAL REVIEW
Friday, February 4, 2022
Different α-synuclein prion strains cause dementia with Lewy bodies and multiple system atrophy, iatrogenic transmission, what if?
SUNDAY, MARCH 4, 2018
Can Aβ Seeds Be Transferred During Neurosurgery?
Thursday, March 8, 2018
Familial human prion diseases associated with prion protein mutations Y226X and G131V are transmissible to transgenic mice expressing human prion protein
THURSDAY, FEBRUARY 15, 2018
Iatrogenic Creutzfeldt-Jakob disease with Amyloid-β pathology: an international study
MSA prions exhibit remarkable stability and resistance to inactivation
Amanda L. WoermanSabeen A. KazmiSmita PatelYevgeniy FreymanAbby OehlerAtsushi AoyagiDaniel A. MordesGlenda M. HallidayLefkos T. MiddletonSteve M. GentlemanSteven H. OlsonStanley B. PrusinerEmail author
28 August 2017
Abstract
In multiple system atrophy (MSA), progressive neurodegeneration results from the protein α-synuclein misfolding into a self-templating prion conformation that spreads throughout the brain. MSA prions are transmissible to transgenic (Tg) mice expressing mutated human α-synuclein (TgM83+/−), inducing neurological disease following intracranial inoculation with brain homogenate from deceased patient samples. Noting the similarities between α-synuclein prions and PrP scrapie (PrPSc) prions responsible for Creutzfeldt–Jakob disease (CJD), we investigated MSA transmission under conditions known to result in PrPSc transmission. When peripherally exposed to MSA via the peritoneal cavity, hind leg muscle, and tongue, TgM83+/− mice developed neurological signs accompanied by α-synuclein prions in the brain. Iatrogenic CJD, resulting from PrPSc prion adherence to surgical steel instruments, has been investigated by incubating steel sutures in contaminated brain homogenate before implantation into mouse brain. Mice studied using this model for MSA developed disease, whereas wire incubated in control homogenate had no effect on the animals. Notably, formalin fixation did not inactivate α-synuclein prions. Formalin-fixed MSA patient samples also transmitted disease to TgM83+/− mice, even after incubating in fixative for 244 months. Finally, at least 10% sarkosyl was found to be the concentration necessary to partially inactivate MSA prions. These results demonstrate the robustness of α-synuclein prions to denaturation. Moreover, they establish the parallel characteristics between PrPSc and α-synuclein prions, arguing that clinicians should exercise caution when working with materials that might contain α-synuclein prions to prevent disease.
Keywords
α-synuclein Neurodegeneration Propagation Proteinopathies Transmission models
***> These results demonstrate the robustness of α-synuclein prions to denaturation.
***> Moreover, they establish the parallel characteristics between PrPSc and α-synuclein prions, arguing that clinicians should exercise caution when working with materials that might contain α-synuclein prions to prevent disease.
THURSDAY, AUGUST 10, 2017
Minimise transmission risk of CJD and vCJD in healthcare settings Updated 10 August 2017
Friday, January 29, 2016
Synucleinopathies: Past, Present and Future, iatrogenic, what if?
Alzheimer's, iatrogenic, transmissible, tse, prion, what if ?
Wednesday, September 9, 2015
*** Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
Tuesday, September 8, 2015
Evidence for α-synuclein prions causing multiple system atrophy in humans with parkinsonism
FRIDAY, JANUARY 10, 2014
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
sporadic CJD, along with new TSE prion disease in humans, of which the young are dying, of which long duration of illness from onset of symptoms to death have been documented, only to have a new name added to the pot of prion disease i.e. sporadic GSS, sporadic FFI, and or VPSPR.
I only ponder how a familial type disease could be sporadic with no genetic link to any family member?
when the USA is the only documented Country in the world to have documented two different cases of atypical H-type BSE, with one case being called atypical H-G BSE with the G meaning Genetic, with new science now showing that indeed atypical H-type BSE is very possible transmitted to cattle via oral transmission (Prion2014). sporadic CJD and VPSPR have been rising in Canada, USA, and the UK, with the same old excuse, better surveillance.
You can only use that excuse for so many years, for so many decades, until one must conclude that CJD TSE prion cases are rising. a 48% increase in CJD in Canada is not just a blip or a reason of better surveillance, it is a mathematical rise in numbers.
More and more we are seeing more humans exposed in various circumstance in the Hospital, Medical, Surgical arenas to the TSE Prion disease, and at the same time in North America, more and more humans are becoming exposed to the TSE prion disease via consumption of the TSE prion via deer and elk, cattle, sheep and goats, and for those that are exposed via or consumption, go on to further expose many others via the iatrogenic modes of transmission of the TSE prion disease i.e. friendly fire.
I pondered this mode of transmission via the victims of sporadic FFI, sporadic GSS, could this be a iatrogenic event from someone sub-clinical with sFFI or sGSS ? what if?
Sunday, September 7, 2014
Twice as many cases of early dementia than was thought Alzheimer’s Society, the London School of Economics and the Institute of Psychiatry
FRIDAY, JANUARY 10, 2014
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what if ???
Greetings Friends, Neighbors, and Colleagues,
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what if ???
Confucius is confused again. I was just sitting and thinking about why there is no genetic link to some of these TSE prion sGSS, sFFi, and it’s really been working on my brain, and then it hit me today.
what if, vpspr, sgss, sffi, TSE prion disease, was a by-product from iatrogenic gss, ffi, familial type prion disease ???
it could explain the cases of no genetic link to the gss, ffi, familial type prion disease, to the family. sporadic and familial is a red herring, in my opinion, and underestimation is spot on, due to the crude prehistoric diagnostic procedures and criteria and definition of a prion disease.
I say again, what if, iatrogenic, what if, with all these neurological disorders, with a common denominator that is increasingly showing up in the picture, called the prion.
I urge all scientist to come together here, with this as the utmost of importance about all these neurological disease that are increasingly showing up as a prion mechanism, to put on the front burners, the IATROGENIC aspect and the potential of transmission there from, with diseases/disease???
in question. by definition, could they be a Transmissible Spongiform Encephalopathy TSE prion type disease, and if so, what are the iatrogenic chances of transmission?
this is very important, and should be at the forefront of research, and if proven, could be a monumental breakthrough in science and battle against the spreading of these disease/diseases.
sporadic CJD, along with new TSE prion disease in humans, of which the young are dying, of which long duration of illness from onset of symptoms to death have been documented, only to have a new name added to the pot of prion disease i.e. sporadic GSS, sporadic FFI, and or VPSPR.
I only ponder how a familial type disease could be sporadic with no genetic link to any family member?
when the USA is the only documented Country in the world to have documented two different cases of atypical H-type BSE, with one case being called atypical H-G BSE with the G meaning Genetic, with new science now showing that indeed atypical H-type BSE is very possible transmitted to cattle via oral transmission (Prion2014).
sporadic CJD and VPSPR have been rising in Canada, USA, and the UK, with the same old excuse, better surveillance.
You can only use that excuse for so many years, for so many decades, until one must conclude that CJD TSE prion cases are rising. a 48% incease in CJD in Canada is not just a blip or a reason of better surveillance, it is a mathematical rise in numbers.
More and more we are seeing more humans exposed in various circumstance in the Hospital, Medical, Surgical arenas to the TSE Prion disease, and at the same time in North America, more and more humans are becoming exposed to the TSE prion disease via consumption of the TSE prion via deer and elk, cattle, sheep and goats, and for those that are exposed via or consumption, go on to further expose many others via the iatrogenic modes of transmission of the TSE prion disease i.e. friendly fire.
I pondered this mode of transmission via the victims of sporadic FFI, sporadic GSS, could this be a iatrogenic event from someone sub-clinical with sFFI or sGSS ? what if?
Wednesday, May 16, 2012
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Terry S. Singeltary Sr. Proposal ID: 29403
MONDAY, DECEMBER 18, 2023
Change in Epidemiology of Creutzfeldt-Jakob Disease in the US, 2007-2020
TUESDAY, DECEMBER 12, 2023
CREUTZFELDT JAKOB DISEASE TSE PRION DISEASE UPDATE USA DECEMBER 2023
SUNDAY, NOVEMBER 26, 2023
The role of environmental factors on sporadic Creutzfeldt-Jakob disease mortality: evidence from an age-period-cohort analysis
What if Cwd tse prion has already transmitted to humans, and is being masked as sporadic cjd, what if$$$
What if Chronic Wasting Disease CWD to humans has become iatrogenic already, and exposed who knows how many humans via the medical, surgical, dental, tissue, blood?
Zoonotic, Zoonosis, Chronic Wasting Disease CWD TSE Prion, Cervids, to Humans, Has Already Happened As Sporadic CJD?
CHRONIC WASTING DISEASE CWD TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE ZOONOSIS, ZOONOTIC
Chronic Wasting Disease CWD TSE Prion of Cervid Zoonosis to humans, iatrogenic transmission, what if?
To date, there has been no proof of spontaneous TSE prion in any species in the field, that's just the facts, to date. the nvCJD or what is called vCJD today, they keep claiming that is over, yet, sporadic CJD is growing, and environmental factors are pointing to sporadic CJD now. please take heed, CWD of Cervids has been linked to sporadic CJD, and just might be the nvCJD nightmare epidemic everyone missed, and with the recent potential cjd occupational exposure in Spain now, and the recent documented 2 deaths of iatrogenic sheep BSE transmission to lab workers as nvCJD, now think CWD exposure, and iatrogenic transmission there from.
Today, there is more science showing that CWD will transmit to humans, yet no call has been made, than there was with nvCJD back in 1995, imo, some decade passed that infamous day back in 1984ish, when Carol Richard, kinda documented something, the next year 1985, Mad Cow was confirmed, typical c-type BSE. what are we waiting for, who makes that call officially that CWD has transmitted to humans, and make urgent precautions in the medical, dental, surgical, tissue, blood donor, fields, how many do we expose, and or, how many have to die? with hundreds of thousands of humans exposed to CWD either directly or indirectly via friendly fire, across the USA and Canada, Who will bare that Burdon of ignorance for not sounding the alarm for CWD to humans, that sCJD was zoonotic zoonosis from all of the above, when the evidence had been staring us in the face for decades? how many more cases of sporadic cjd linked to CWD are we going to pass off as just a happenstance of bad luck, spontaneous, when no documented case has ever been proven of spontaneous CJD? How many humans has to be exposed and die, and or friendly fire, iatrogenic cjd, before a call of CWD zoonosis is made for cwd to humans? remember, all iatrogenic cjd is, is sporadic cjd, there needs to be a global consortium of TSE Prion scientist and medical, surgical, scientist, to hold such a meeting as to making that final call that cwd is transmissible to humans, and then make the decisions to safeguard public health from iatrogenic cwd to humans.
all iatrogenic cjd is, is sporadic cjd, before the iatrogenic event is discovered, traced back, proven, documented, put into the academic domain, and then finally the public domain, this very seldom happens, thus problem solved, it's all sporadic cjd.
HOW long are we going to wait for Chronic Wasting Disease, CWD TSE Prion of Cervid, and zoonosis, zoonotic transmission to humans there from?
Studies have shown since 1994 that humans are susceptible to CWD TSE Prion, so, what's the hold up with making CWD a zoonotic zoonosis disease, the iatrogenic transmissions there from is not waiting for someone to make a decision. I remind everyone of Creutzfeldt-Jakob disease from growth hormone deficient children, and those 35 or so children that succumbed to CJD hGH recipients, or the dura mater graft-associated Creutzfeldt-Jakob disease around the world, I’ve lost count on total mortality to date from that, or the recent iatrogenic cases of nvCJD, from occupational iatrogenic associate exposure in Spain and France working with BSE, and we cannot forget the blood related deaths from nvCJD. Blood from CWD is highly infectious. Do we just ignore this, in terms of CWD? A foolish move, imo...see references at the bottom of this page!
Friendly fire, pass it forward, they call it iatrogenic cjd, or what i call 'tse prion poker', are you all in $$$
Terry S. Singeltary Sr.
Two Hunters from the Same Lodge Afflicted with Sporadic CJD: Is Chronic Wasting Disease to Blame?
(P7-13.002) Jonathan Trout, Matthew Roberts, Michel Tabet, Eithan Kotkowski, and Sarah HornAUTHORS INFO & AFFILIATIONS April 9, 2024 issue 102 (17_supplement_1) https://doi.org/10.1212/WNL.0000000000204407
Abstract Publication History Information & Authors Metrics & Citations Share Abstract
Objective:
This study presents a cluster of Creutzfeldt-Jakob disease (CJD) cases after exposure to chronic wasting disease (CWD)-infected deer, suggestive of potential prion transmission from CWD-infected deer to humans.
Background:
CJD is a rapidly progressive central nervous system disorder caused by misfolded prion proteins. CWD, a prion disease prevalent in North American deer, has raised concerns due to its possible link to CJD. Although no conclusive evidence of cross-species prion transmission exists, vigilance for such cases is crucial for public health.
Design/Methods:
Not applicable.
Results:
In 2022, a 72-year-old man with a history of consuming meat from a CWD-infected deer population presented with rapid-onset confusion and aggression. His friend, who had also eaten venison from the same deer population, recently died of CJD, raising concerns about a potential link between CWD and human prion disease. Despite aggressive symptomatic treatment of seizures and agitation, the patient’s condition deteriorated and he died within a month of initial presentation. The diagnosis was confirmed postmortem as sporadic CJD with homozygous methionine at codon 129 (sCJDMM1). The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD. Based on non-human primate and mouse models, cross-species transmission of CJD is plausible. Due to the challenge of distinguishing sCJDMM1 from CWD without detailed prion protein characterization, it is not possible to definitively rule out CWD in these cases. Although causation remains unproven, this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health.
Conclusions:
Clusters of sporadic CJD cases may occur in regions with CWD-confirmed deer populations, hinting at potential cross-species prion transmission. Surveillance and further research are essential to better understand this possible association.
Disclosure: Mr. Trout has nothing to disclose. Dr. Roberts has nothing to disclose. Dr. Tabet has nothing to disclose. Dr. Kotkowski has nothing to disclose. Dr. Horn has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cala Trio. The institution of Dr. Horn has received research support from Alzheimer's Association.
TUESDAY, MAY 11, 2021
A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet
Conclusion
We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.
Supplemental data including molecular tissue sample analysis and autopsy findings could yield further supporting evidence. Given this patient’s clinical resemblance to CBD and the known histological similarities of CBD with CJD, clinicians should consider both diseases in the differential diagnosis of patients with a similarly esoteric presentation. Regardless of the origin of this patient’s disease, it is clear that the potential for prion transmission from cervids to humans should be further investigated by the academic community with considerable urgency.
''We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.''
CREUTZFELDT JAKOB DISEASE: A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet
i was warning England and the BSE Inquiry about just this, way back in 1998, and was ask to supply information to the BSE Inquiry. for anyone that might be interested, see;
Singeltary submission to the BSE Inquiry on CJD and Nutritional Supplements 1998
ABOUT that deer antler spray and CWD TSE PRION... I have been screaming this since my neighbors mom died from cjd, and she had been taking a supplement that contained bovine brain, bovine eyeball, and other SRMs specified risk materials, the most high risk for mad cow disease. just saying...
I made a submission to the BSE Inquiry long ago during the BSE Inquiry days, and they seemed pretty interested.
Sender: "Patricia Cantos"
To: "Terry S Singeltary Sr. (E-mail)"
Subject: Your submission to the Inquiry
Date: Fri, 3 Jul 1998 10:10:05 +0100 3 July 1998
Mr Terry S Singeltary Sr. E-Mail: Flounder at wt.net Ref: E2979
Dear Mr Singeltary, Thank you for your E-mail message of the 30th of June 1998 providing the Inquiry with your further comments. Thank you for offering to provide the Inquiry with any test results on the nutritional supplements your mother was taking before she died. As requested I am sending you our general Information Pack and a copy of the Chairman's letter. Please contact me if your system cannot read the attachments. Regarding your question, the Inquiry is looking into many aspects of the scientific evidence on BSE and nvCJD.
I would refer you to the transcripts of evidence we have already heard which are found on our internet site at ;
http://www.bse.org.uk.
Could you please provide the Inquiry with a copy of the press article you refer to in your e-mail? If not an approximate date for the article so that we can locate it? In the meantime, thank you for you comments. Please do not hesitate to contact me on... snip...end...tss
everyone I tell this too gets it screwed up...MY MOTHER WAS NOT TAKING THOSE SUPPLEMENTS IPLEX (that I ever knew of). this was my neighbors mother that died exactly one year previously and to the day of sporadic CJD that was diagnosed as Alzheimer’s at first. my mother died exactly a year later from the Heidenhain Variant of Creutzfeldt Jakob Disease hvCJD, and exceedingly rare strains of the ever growing sporadic CJD’s. both cases confirmed. ...kind regards, terry
“If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.”
PART 2. TPWD CHAPTER 65. DIVISION 1. CWD
31 TAC §§65.82, 65.85, 65.88
The Texas Parks and Wildlife Commission in a duly noticed meeting on May 25, 2023 adopted amendments to 31 TAC §§65.82, 65.85, and §65.88, concerning Disease Detection and Response, without changes to the proposed text as published in the April 21, 2023, issue of the Texas Register (48 TexReg 2048). The rules will not be republished.
Currently, there is scientific evidence to suggest that CWD has zoonotic potential; however, no confirmed cases of CWD have been found in humans.
17 DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
Rebeca Benavente1, Francisca Bravo1,2, Paulina Soto1,2, J. Hunter Reed3, Mitch Lockwood3, Rodrigo Morales1,2
1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA. 2Universidad Bernardo O’Higgins, Santiago, Chile. 3Texas Parks and Wildlife, Austin, USA
Abstract
The zoonotic potential of chronic wasting disease (CWD) remains unknown. Currently, there are no known natural cases of CWD transmission to humans but increasing evidence suggests that the host range of CWD is not confined only to cervid species. Alarmingly, recent experimental evidence suggests that certain CWD isolates can induce disease in non-human primates. While the CDC strongly recommends determining CWD status in animals prior to consumption, this practice is voluntary. Consequently, it is plausible that a proportion of the cervid meat entering the human food chain may be contaminated with CWD. Of additional concern is that traditional diagnostic techniques used to detect CWD have relatively low sensitivity and are only approved for use in tissues other than those typically ingested by humans. In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
***> Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
***> CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
***> Our results show positive prion detection in all products.
***> Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
***> Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
=====
9 Carrot plants as potential vectors for CWD transmission.
Paulina Soto1,2, Francisca Bravo-Risi1,2, Claudio Soto1, Rodrigo Morales1,2
1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA. 2Universidad Bernardo O’Higgins, Santiago, Chile
***> We show that edible plant components can absorb prions from CWD-contaminated soils and transport them to their aerial parts.
***> Our results indicate that edible plants could participate as vectors of CWD transmission
=====
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
=====
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286 The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
================================
Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650 mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
=================================
Supplementary Information The online version contains supplementary material available at
snip...see full text
Fortuitous generation of a zoonotic cervid prion strain
Manuel Camacho, Xu Qi, Liuting Qing, Sydney Smith, Jieji Hu, Wanyun Tao, Ignazio Cali, Qingzhong Kong. Department of Pathology, Case Western Reserve University, Cleveland, USA
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in many states or provinces of USA and Canada. Multiple in vitro conversion experiments and in vivo animal studies indicate that the CWD-to-human transmission barrier is not unbreakable. A major long-term public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Materials and Methods: We inoculated several sCJD brain samples into cervidized transgenic mice (Tg12), which were intended as negative controls for bioassays of brain tissues from sCJD cases who had potentially been exposed to CWD. Some of the Tg12 mice became infected and their brain tissues were further examined by Western blot as well as serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a “cervidized” CJD strain that we termed CJDElkPrP. We observed 100% transmission of the original CJDElkPrP in transgenic mice expressing human PrP. We passaged CJDElkPrP two more times in the Tg12 mice. We found that such second and third passage CJDElkPrP prions retained 100% transmission rate in the humanized mice, despite that the natural elk CWD isolates and CJDElkPrP share the same elk PrP sequence. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice.
Conclusions: Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time.
Funded by: NIH Grant number: R01NS052319, R01NS088604, R01NS109532
Acknowledgement: We want to thank the National Prion Disease Pathology Surveillance Center and Drs. Allen Jenny and Katherine O'Rourke for providing the sCJD samples and the CWD samples used in this study, respectively
"Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time."
PRION 2023 TO BE CONTINUED;
what if?
P132 Aged cattle brain displays Alzheimer’s-like pathology that can be propagated in a prionlike manner
Ines Moreno-Gonzalez (1), George Edwards III (1), Rodrigo Morales (1), Claudia Duran-Aniotz (1), Mercedes Marquez (2), Marti Pumarola (2), Claudio Soto (1)
snip...
These results may contribute to uncover a previously unsuspected etiology surrounding some cases of sporadic AD. However, the early and controversial stage of the field of prion-like transmission in non-prion diseases added to the artificial nature of the animal models utilized for these studies, indicate that extrapolation of the results to humans should not be done without further experiments.
P75 Determining transmissibility and proteome changes associated with abnormal bovine prionopathy
Dudas S (1,2), Seuberlich T (3), Czub S (1,2)
In prion diseases, it is believed that altered protein conformation encodes for different pathogenic strains. Currently 3 different strains of bovine spongiform encephalopathy (BSE) are confirmed. Diagnostic tests for BSE are able to identify animals infected with all 3 strains, however, several diagnostic laboratories have reported samples with inconclusive results which are challenging to classify. It was suggested that these may be novel strains of BSE; to determine transmissibility, brain material from index cases were inoculated into cattle.
In the first passage, cattle were intra-cranially challenged with brain homogenate from 2 Swiss animals with abnormal prionopathy. The challenged cattle incubated for 3 years and were euthanized with no clinical signs of neurologic disease. Animals were negative when tested on validated diagnostic tests but several research methods demonstrated changes in the prion conformation in these cattle, including density gradient centrifugation and immunohistochemistry. Currently, samples from the P1 animals are being tested for changes in protein levels using 2-D Fluorescence Difference Gel Electrophoresis (2D DIGE) and mass spectrometry. It is anticipated that, if a prionopathy is present, this approach should identify pathways and targets to decipher the source of altered protein conformation. In addition, a second set of cattle have been challenged with brain material from the first passage. Ideally, these cattle will be given a sufficient incubation period to provide a definitive answer to the question of transmissibility.
=====prion 2018===
***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts
S67 PrPsc was not detected using rapid tests for BSE.
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
*** IBNC Tauopathy or TSE Prion disease, it appears, no one is sure ***
Posted by Terry S. Singeltary Sr. on 03 Jul 2015 at 16:53 GMT
Terry S. Singeltary Sr.
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