scholarly journals Alteration of Prion Strain Emergence by Nonhost Factors

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Sara A. M. Holec ◽  
Qi Yuan ◽  
Jason C. Bartz

ABSTRACT Prions can persist in the environment for extended periods of time after adsorption to surfaces, including soils, feeding troughs, or fences. Prion strain- and soil-specific differences in prion adsorption, infectivity, and response to inactivation may be involved in strain maintenance or emergence of new strains in a population. Extensive proteinase K (PK) digestion of Hyper (HY) and Drowsy (DY) PrPSc resulted in a greater reduction in the level of DY PrPSc than of HY PrPSc. Use of the PK-digested material in protein misfolding cyclic amplification strain interference (PMCAsi) resulted in earlier emergence of HY PrPSc than of undigested controls. This result established that strain-specific alteration of the starting ratios of conversion-competent HY and DY PrPSc can alter strain emergence. We next investigated whether environmentally relevant factors such as surface binding and weathering could alter strain emergence. Adsorption of HY and DY PrPSc to silty clay loam (SCL), both separately and combined, resulted in DY interfering with the emergence of HY in PMCAsi in a manner similar to that seen with unbound controls. Similarly, repeated cycles of wetting and drying of SCL-bound HY and DY PrPSc did not alter the emergence of HY PrPSc compared to untreated controls. Importantly, these data indicate that prion strain interference can occur when prions are bound to surfaces. Interestingly, we found that drying of adsorbed brain homogenate on SCL could restore its ability to interfere with the emergence of HY, suggesting a novel strain interference mechanism. Overall, these data provide evidence that the emergence of a strain from a mixture can be influenced by nonhost factors. IMPORTANCE The prion strain, surface type, and matrix containing PrPSc can influence PrPSc surface adsorption. The cumulative effect of these factors can result in strain- and soil-specific differences in prion bioavailability. Environmental weathering processes can result in decreases in PrPSc conversion efficiency and infectivity. Little is known about how incomplete inactivation of surface-bound PrPSc affects transmission and prion strain emergence. Here, we show that strain interference occurs with soil-bound prions and that altering the ratios of prion strains by strain-specific inactivation can affect strain emergence. Additionally, we identify a novel mechanism of inhibition of prion conversion by environmental treatment-induced changes at the soil-protein interface altering strain emergence. These novel findings suggest that environmental factors can influence strain emergence of surface-bound prions.

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 947
Author(s):  
Akikazu Sakudo ◽  
Risa Yamashiro ◽  
Chihiro Harata

To date, there have been no studies on the sterilization of prions by non-concentrated and concentrated vaporized hydrogen peroxide (VHP) applied by the same instrument. Here, the effect of the two types of VHP applied using an ES-700 sterilizer on prions was investigated. Brain homogenate from scrapie (Chandler) prion-infected mice was spotted on a cover glass and subjected to ES-700 treatment in soft (non-concentrated VHP from 59% hydrogen peroxide) or standard (concentrated VHP from 80% hydrogen peroxide) mode. Proteinase K-resistant prion protein (PrPres), an indicator of the abnormal isoform of prion protein (PrPSc), was reduced by ES-700 treatment under several conditions: SFT1/4 (soft mode, quarter cycle), SFT1/2 (soft mode, half cycle), SFT1 (soft mode, full cycle), and STD1/2 (standard mode, half cycle). PrPres was detected after the first and second rounds of protein misfolding cyclic amplification (PMCA) of untreated samples, but was undetectable in SFT1/4, SFT1/2, SFT1, and STD1/2 treated samples. In a mouse bioassay, SFT1/2 and STD1/2 treatment of prions significantly prolonged survival time, suggesting that prion infectivity is reduced after ES-700 treatment. In summary, both non-concentrated and concentrated VHP inactivate prions and may be useful for the low-temperature sterilization of prion-contaminated medical devices.


mSphere ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Crystal Meyerett-Reid ◽  
A. Christy Wyckoff ◽  
Terry Spraker ◽  
Bruce Pulford ◽  
Heather Bender ◽  
...  

ABSTRACT CWD is the only known TSE that affects free-ranging wildlife, specifically cervids such as elk, deer, moose, caribou, and reindeer. CWD has become endemic in both free-ranging and captive herds in North America, South Korea, and, most recently, northern Europe. The prion research community continues to debate the origins of CWD. Original foci of CWD emergence in Colorado and Wyoming coincident with the sheep TSE scrapie suggest that scrapie prions may have adapted to cervids to cause CWD. However, emerging evidence supports the idea that cervid PrPC may be more prone to misfolding to the pathological isoform. Here we test the hypothesis that cervid PrPC can spontaneously misfold to create de novo prions. Whether CWD can arise spontaneously as a sporadic TSE or represents a new TSE caused by cervid-adapted scrapie prions profoundly impacts surveillance and mitigation strategies. Substantial evidence supports the hypothesis that prions are misfolded, infectious, insoluble, and protease-resistant proteins (PrPRES) devoid of instructional nucleic acid that cause transmissible spongiform encephalopathies (TSEs). Protein misfolding cyclic amplification (PMCA) has provided additional evidence that PrPRes acts as a template that can convert the normal cellular prion protein (PrPC) present in uninfected normal brain homogenate (NBH) into the infectious misfolded PrPRES isoform. Human PrPC has been shown to spontaneously convert to a misfolded pathological state causing sporadic Creutzfeldt-Jakob disease (sCJD). Several investigators have reported spontaneous generation of prions by in vitro assays, including PMCA. Here we tested the rate of de novo generation of cervid prions in our laboratory using our standard PMCA protocol and NBH from transgenic mice expressing cervid PrPC (TgCerPrP mice). We generated de novo prions in rounds 4, 5, and 7 at low cumulative rates of 1.6, 5.0, and 6.7%, respectively. The prions caused infectious chronic wasting disease (CWD) upon inoculation into normal uninfected TgCerPrP mice and displayed unique biochemical characteristics compared to other cervid prion strains. We conclude that PMCA of cervid PrPC from normal brain homogenate spontaneously generated a new cervid prion strain. These data support the potential for cervids to develop sporadic CWD. IMPORTANCE CWD is the only known TSE that affects free-ranging wildlife, specifically cervids such as elk, deer, moose, caribou, and reindeer. CWD has become endemic in both free-ranging and captive herds in North America, South Korea, and, most recently, northern Europe. The prion research community continues to debate the origins of CWD. Original foci of CWD emergence in Colorado and Wyoming coincident with the sheep TSE scrapie suggest that scrapie prions may have adapted to cervids to cause CWD. However, emerging evidence supports the idea that cervid PrPC may be more prone to misfolding to the pathological isoform. Here we test the hypothesis that cervid PrPC can spontaneously misfold to create de novo prions. Whether CWD can arise spontaneously as a sporadic TSE or represents a new TSE caused by cervid-adapted scrapie prions profoundly impacts surveillance and mitigation strategies. Podcast: A podcast concerning this article is available.


Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Akikazu Sakudo ◽  
Daiki Anraku ◽  
Tomomasa Itarashiki

Prion diseases are proteopathies that cause neurodegenerative disorders in humans and animals. Prion is highly resistant to both chemical and physical inactivation. Here, vaporized gas derived from a hydrogen peroxide–peracetic acid mixture (VHPPA) was evaluated for its ability to inactivate prion using a STERIACE 100 instrument (Saraya Co., Ltd.). Brain homogenates of scrapie (Chandler strain) prion-infected mice were placed on a cover glass, air-dried, sealed in a Tyvek package, and subjected to VHPPA treatment at 50–55 °C using 8% hydrogen peroxide and <10% peracetic acid for 47 min (standard mode, SD) or 30 min (quick mode, QC). Untreated control samples were prepared in the same way but without VHPPA. The resulting samples were treated with proteinase K (PK) to separate PK-resistant prion protein (PrPres), as a marker of the abnormal isoform (PrPSc). Immunoblotting showed that PrPres was reduced by both SD and QC VHPPA treatments. PrPres bands were detected after protein misfolding cyclic amplification of control but not VHPPA-treated samples. In mice injected with prion samples, VHPPA treatment of prion significantly prolonged survival relative to untreated samples, suggesting that it decreases prion infectivity. Taken together, the results show that VHPPA inactivates prions and might be applied to the sterilization of contaminated heat-sensitive medical devices.


2010 ◽  
Vol 84 (11) ◽  
pp. 5706-5714 ◽  
Author(s):  
Ronald A. Shikiya ◽  
Jacob I. Ayers ◽  
Charles R. Schutt ◽  
Anthony E. Kincaid ◽  
Jason C. Bartz

ABSTRACT Prion strain interference can influence the emergence of a dominant strain from a mixture; however, the mechanisms underlying prion strain interference are poorly understood. In our model of strain interference, inoculation of the sciatic nerve with the drowsy (DY) strain of the transmissible mink encephalopathy (TME) agent prior to superinfection with the hyper (HY) strain of TME can completely block HY TME from causing disease. We show here that the deposition of PrPSc, in the absence of neuronal loss or spongiform change, in the central nervous system corresponds with the ability of DY TME to block HY TME infection. This suggests that DY TME agent-induced damage is not responsible for strain interference but rather prions compete for a cellular resource. We show that protein misfolding cyclic amplification (PMCA) of DY and HY TME maintains the strain-specific properties of PrPSc and replicates infectious agent and that DY TME can interfere, or completely block, the emergence of HY TME. DY PrPSc does not convert all of the available PrPC to PrPSc in PMCA, suggesting the mechanism of prion strain interference is due to the sequestering of PrPC and/or other cellular components required for prion conversion. The emergence of HY TME in PMCA was controlled by the initial ratio of the TME agents. A higher ratio of DY to HY TME agent is required for complete blockage of HY TME in PMCA compared to several previous in vivo studies, suggesting that HY TME persists in animals coinfected with the two strains. This was confirmed by PMCA detection of HY PrPSc in animals where DY TME had completely blocked HY TME from causing disease.


2018 ◽  
Vol 92 (8) ◽  
Author(s):  
Qi Yuan ◽  
Glenn Telling ◽  
Shannon L. Bartelt-Hunt ◽  
Jason C. Bartz

ABSTRACTChronic wasting disease (CWD) is an emerging prion disease in North America. Recent identification of CWD in wild cervids from Norway raises the concern of the spread of CWD in Europe. CWD infectivity can enter the environment through live animal excreta and carcasses where it can bind to soil. Well-characterized hamster prion strains and CWD field isolates in unadsorbed or soil-adsorbed forms that were either hydrated or dehydrated were subjected to repeated rounds of freezing and thawing. We found that 500 cycles of repeated freezing and thawing of hydrated samples significantly decreased the abundance of PrPScand reduced protein misfolding cyclic amplification (PMCA) seeding activity that could be rescued by binding to soil. Importantly, dehydration prior to freezing and thawing treatment largely protected PrPScfrom degradation, and the samples maintained PMCA seeding activity. We hypothesize that redistribution of water molecules during the freezing and thawing process alters the stability of PrPScaggregates. Overall, these results have significant implications for the assessment of prion persistence in the environment.IMPORTANCEPrions excreted into the environment by infected animals, such as elk and deer infected with chronic wasting disease, persist for years and thus facilitate horizontal transmission of the disease. Understanding the fate of prions in the environment is essential to control prion disease transmission. The significance of our study is that it provides information on the possibility of prion degradation and inactivation under natural weathering processes. This information is significant for remediation of prion-contaminated environments and development of prion disease control strategies.


2019 ◽  
Vol 116 (52) ◽  
pp. 26853-26862 ◽  
Author(s):  
Alvina Huor ◽  
Juan Carlos Espinosa ◽  
Enric Vidal ◽  
Hervé Cassard ◽  
Jean-Yves Douet ◽  
...  

Atypical/Nor98 scrapie (AS) is a prion disease of small ruminants. Currently there are no efficient measures to control this form of prion disease, and, importantly, the zoonotic potential and the risk that AS might represent for other farmed animal species remains largely unknown. In this study, we investigated the capacity of AS to propagate in bovine PrP transgenic mice. Unexpectedly, the transmission of AS isolates originating from 5 different European countries to bovine PrP mice resulted in the propagation of the classical BSE (c-BSE) agent. Detection of prion seeding activity in vitro by protein misfolding cyclic amplification (PMCA) demonstrated that low levels of the c-BSE agent were present in the original AS isolates. C-BSE prion seeding activity was also detected in brain tissue of ovine PrP mice inoculated with limiting dilutions (endpoint titration) of ovine AS isolates. These results are consistent with the emergence and replication of c-BSE prions during the in vivo propagation of AS isolates in the natural host. These data also indicate that c-BSE prions, a known zonotic agent in humans, can emerge as a dominant prion strain during passage of AS between different species. These findings provide an unprecedented insight into the evolution of mammalian prion strain properties triggered by intra- and interspecies passage. From a public health perspective, the presence of c-BSE in AS isolates suggest that cattle exposure to small ruminant tissues and products could lead to new occurrences of c-BSE.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Nara Lins ◽  
Luiz Mourão ◽  
Nonata Trévia ◽  
Aline Passos ◽  
José Augusto Farias ◽  
...  

We investigated possible interaction between an arbovirus infection and the ME7 induced mice prion disease. C57BL/6, females, 6-week-old, were submitted to a bilateral intrahippocampal injection of ME7 prion strain (ME7) or normal brain homogenate (NBH). After injections, animals were organized into two groups: NBH (n=26) and ME7 (n=29). At 15th week after injections (wpi), animals were challenged intranasally with a suspension of Piry arbovirus 0.001% or with NBH. Behavioral changes in ME7 animals appeared in burrowing activity at 14 wpi. Hyperactivity on open field test, errors on rod bridge, and time reduction in inverted screen were detected at 15th, 19th, and 20th wpi respectively. Burrowing was more sensitive to earlier hippocampus dysfunction. However, Piry-infection did not significantly affect the already ongoing burrowing decline in the ME7-treated mice. After behavioral tests, brains were processed for IBA1, protease-resistant form of PrP, and Piry virus antigens. Although virus infection in isolation did not change the number of microglia in CA1, virus infection in prion diseased mice (at 17th wpi) induced changes in number and morphology of microglia in a laminar-dependent way. We suggest that virus infection exacerbates microglial inflammatory response to a greater degree in prion-infected mice, and this is not necessarily correlated with hippocampal-dependent behavioral deficits.


2010 ◽  
Vol 91 (8) ◽  
pp. 2121-2131 ◽  
Author(s):  
Mourad Tayebi ◽  
William Alexander Taylor ◽  
Daryl Rhys Jones ◽  
Clive Bate ◽  
Monique David

Although there is currently no effective treatment for prion diseases, significant advances have been made in suppressing its progress, using antibodies that block the conversion of PrPC into PrPSc. In order to be effective in treating individuals that have prion diseases, antibodies must be capable of arresting disease in its late stages. This requires the development of antibodies with higher affinity for PrPSc and systems for effective translocation of antibodies across the blood–brain barrier in order to achieve high concentrations of inhibitor at the site of protein replication. An additional advantage is the ability of these antibodies to access the cytosol of affected cells. To this end, we have generated PrP-specific antibodies (known as PrioV) by immunization of camels with murine scrapie material adsorbed to immunomagnetic beads. The PrioV antibodies display a range of specificities with some recognizing the PrP27–30 proteinase K-resistant fragment, others specific for PrPC and a number with dual binding specificity. Independent of their PrP conformation specificity, one of the PrioV antibodies (PrioV3) was shown to bind PrPC in the cytosol of neuroblastoma cells. In marked contrast, conventional anti-PrP antibodies produced in mouse against similar target antigen were unable to cross the neuronal plasma membrane and instead formed a ring around the cells. The PrioV anti-PrP antibodies could prove to be a valuable tool for the neutralization/clearance of PrPSc in intracellular compartments of affected neurons and could potentially have wider applicability for the treatment of so-called protein-misfolding diseases.


2009 ◽  
Vol 83 (8) ◽  
pp. 3852-3860 ◽  
Author(s):  
Ryo Shindoh ◽  
Chan-Lan Kim ◽  
Chang-Hyun Song ◽  
Rie Hasebe ◽  
Motohiro Horiuchi

ABSTRACT Although the major component of the prion is believed to be the oligomer of PrPSc, little information is available concerning regions on the PrPSc molecule that affect prion infectivity. During the analysis of PrPSc molecules from various prion strains, we found that PrPSc of the Chandler strain showed a unique property in the conformational-stability assay, and this property appeared to be useful for studying the relationship between regions of the PrPSc molecule and prion infectivity. Thus, we analyzed PrPSc of the Chandler strain in detail and analyzed the infectivities of the N-terminally denatured and truncated forms of proteinase K-resistant PrP. The N-terminal region of PrPSc of the Chandler strain showed region-dependent resistance to guanidine hydrochloride (GdnHCl) treatment. The region approximately between amino acids (aa) 81 and 137 began to be denatured by treatment with 1.5 M GdnHCl. Within this stretch, the region comprising approximately aa 81 to 90 was denatured almost completely by 2 M GdnHCl. Furthermore, the region approximately between aa 90 and 137 was denatured completely by 3 M GdnHCl. However, the C-terminal region thereafter was extremely resistant to the GdnHCl treatment. This property was not observed in PrPSc molecules of other prion strains. Denaturation of the region between aa 81 and 137 by 3 M GdnHCl significantly prolonged the incubation periods in mice compared to that for the untreated control. More strikingly, the denaturation and removal of this region nearly abolished the infectivity. This finding suggests that the conformation of the region between aa 81 and 137 of the Chandler strain PrPSc molecule is directly associated with prion infectivity.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Edoardo Bistaffa ◽  
Alba Marín-Moreno ◽  
Juan Carlos Espinosa ◽  
Chiara Maria Giulia De Luca ◽  
Federico Angelo Cazzaniga ◽  
...  

Background:Fatal Familial Insomnia (FFI) is a genetic prion disease caused by the D178N mutation in the prion protein gene (PRNP) in coupling phase with methionine at PRNP 129. In 2017, we have shown that the olfactory mucosa (OM) collected from FFI patients contained traces of PrPSc detectable by Protein Misfolding Cyclic Amplification (PMCA).Methods:In this work, we have challenged PMCA-generated products obtained from OM and brain homogenate of FFI patients in BvPrP-Tg407 transgenic mice expressing the bank vole prion protein to test their ability to induce prion pathology.Results:All inoculated mice developed mild spongiform changes, astroglial activation, and PrPSc deposition mainly affecting the thalamus. However, their neuropathological alterations were different from those found in the brain of BvPrP-Tg407 mice injected with raw FFI brain homogenate.Conclusions:Although with some experimental constraints, we show that PrPSc present in OM of FFI patients is potentially infectious.Funding:This work was supported in part by the Italian Ministry of Health (GR-2013-02355724 and Ricerca Corrente), MJFF, ALZ, Alzheimer’s Research UK and the Weston Brain Institute (BAND2015), and Euronanomed III (SPEEDY) to FM; by the Spanish Ministerio de Economía y Competitividad (grant AGL2016-78054-R [AEI/FEDER, UE]) to JMT and JCE; AM-M was supported by a fellowship from the INIA (FPI-SGIT-2015-02).


Sign in / Sign up

Export Citation Format

Share Document