Andrew G Hughson

National Institutes of Health | NIH

Prion diseases are transmissible, fatal neurologic diseases of mammals caused by the accumulation of mis-folded, disease associated prion protein (PrPd). Creutzfeldt-Jakob Disease (CJD) is the most common human prion disease and can occur by sporadic onset (sCJD) (~85% of CJD cases), genetic mutations in the prion protein gene (10–15%) or iatrogeni...

Chronic wasting disease (CWD) is a widely distributed prion disease of cervids with implications for wildlife conservation and also for human and livestock health. The structures of infectious prions that cause CWD and other natural prion diseases of mammalian hosts have been poorly understood. Here we report a 2.8 Å resolution cryogenic electron m...

Chronic wasting disease (CWD) is a widely distributed prion disease of cervids with implications for wildlife conservation and also for human and livestock health. The structures of infectious prions that cause CWD and other natural prion diseases of mammalian hosts have been poorly understood. Here we report a 2.8 Å resolution cryogenic electron m...

Chronic wasting disease (CWD) is a cervid prion disease with unknown zoonotic potential that might pose a risk to humans who are exposed. To assess the potential of CWD to infect human neural tissue, we used human cerebral organoids with 2 different prion genotypes, 1 of which has previously been associated with susceptibility to zoonotic prion dis...

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-induce...

Definitive diagnosis of sporadic Creutzfeldt–Jakob disease (sCJD) relies on the examination of brain tissues for the pathological prion protein (PrPSc). Our previous study revealed that PrPSc-seeding activity (PrPSc-SA) is detectable in skin of sCJD patients by an ultrasensitive PrPSc seed amplification assay (PrPSc-SAA) known as real-time quaking-...

Prion diseases are transmissible, fatal neurologic diseases that include Creutzfeldt-Jakob Disease (CJD) in humans, chronic wasting disease (CWD) in cervids, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. Prions are extremely difficult to inactivate and established methods to reduce prion infectivity are often dangerous, cau...

Abnormal deposition of α-synuclein is a key feature and biomarker of Parkinson’s disease. α-Synuclein aggregates can propagate themselves by a prion-like seeding-based mechanism within and between tissues and are hypothesized to move between the intestine and brain. α-Synuclein RT-QuIC seed amplification assays have detected Parkinson’s-associated...

Tau neurofibrillary tangles are a hallmark of Alzheimer’s disease neuropathological change. However, it remains largely unclear how distinctive Alzheimer’s disease tau seeds (i.e. 3R/4R) correlate with histological indicators of tau accumulation. Furthermore, AD tau co-pathology is thought to influence features and progression of other neurodegener...

Human prion diseases are remarkable for long incubation times followed typically by rapid clinical decline. Seed amplification assays and neurodegeneration biofluid biomarkers are remarkably useful in the clinical phase, but their potential to predict clinical onset in healthy people remains unclear. This is relevant not only to the design of preve...

Human cerebral organoids (COs) are three-dimensional self-organizing cultures of cerebral brain tissue differentiated from induced pluripotent stem cells. We have recently shown that COs are susceptible to infection with different subtypes of Creutzfeldt–Jakob disease (CJD) prions, which in humans cause different manifestations of the disease. The...

The seeding activity of prions has been exploited for the development of ultrasensitive assays for prion diseases. Among the more practical are Real-Time Quaking Induced Conversion (RT-QuIC) assays that use recombinant prion protein as a substrate for prion-seeded conversion into amyloid fibrils, shaking rather than sonication, and fluorescence det...

Chronic wasting disease (CWD) is a prion disease of cervids including deer, elk, reindeer, and moose. Human consumption of cervids is common, therefore assessing the risk potential of CWD transmission to humans is critical. In a previous study, we tested CWD transmission via intracerebral inoculation into transgenic mice (tg66 and tgRM) that over-e...

Prion strains in a given type of mammalian host are distinguished by differences in clinical presentation, neuropathological lesions, survival time, and characteristics of the infecting prion protein (PrP) assemblies. Near-atomic structures of prions from two host species with different PrP sequences have been determined but comparisons of distinct...

Human prion diseases are remarkable for long incubation times followed by typically rapid clinical decline. Seed amplification assays and neurodegeneration biofluid biomarkers are remarkably useful in the clinical phase, but their potential to predict clinical onset in healthy people remains unclear. This is relevant not only to the design of preve...

Prion strains in a given type of mammalian host are distinguished by differences in clinical presentation, neuropathological lesions, survival time, and characteristics of the infecting prion protein (PrP) assemblies. Near-atomic structures of prions from two host species with different PrP sequences have been determined but comparisons of distinct...

Currently, there is a need for diagnostic markers in Lewy body disorders (LBD). α-synuclein (αSyn) RT-QuIC has emerged as a promising assay to detect misfolded αSyn in clinically or neuropathologically established patients with various synucleinopathies. In this study, αSyn RT-QuIC was used to analyze lumbar CSF in a clinical cohort from the Swedis...

Currently, there is a need for diagnostic markers in Lewy body disorders (LBD). αSyn RT-QuIC has emerged as a promising assay to detect misfolded α-synuclein in clinically or neuropathologically established patients with various synucleinopathies. In this study, αSyn RT-QuIC was used to analyze lumbar CSF in a clinical cohort from the Swedish BioFI...

Little is known about the structural basis of prion strains. Here we provide a high (3.0 Å) resolution cryo-electron microscopy-based structure of brain-derived fibrils of the mouse anchorless RML scrapie strain which, like the recently determined hamster 263K strain, has a parallel in-register β-sheet-based core. However, detailed comparisons reve...

CWD prions appear to spread naturally among susceptible cervid species in captivity and in the wild. A better understanding of all the ways these prions move, persist, and subsequently infect target species through the environment is critical to developing comprehensive disease control strategies.

During the publication process of the original article [1] an error was made and several corresponding authors were not shown.

Alpha-synuclein seed amplification assays (αSyn-SAAs) are promising diagnostic tools for Parkinson’s disease (PD) and related synucleinopathies. They enable detection of seeding-competent alpha-synuclein aggregates in living patients and have shown high diagnostic accuracy in several PD and other synucleinopathy patient cohorts. However, there has...

Within the extensive range of self-propagating pathologic protein aggregates of mammals, prions are the most clearly infectious (e.g., ∼10⁹ lethal doses per milligram). The structures of such lethal assemblies of PrP molecules have been poorly understood. Here we report a near-atomic core structure of a brain-derived, fully infectious prion (263K s...

Efforts to contain the spread of chronic wasting disease (CWD), a fatal, contagious prion disease of cervids, would be aided by the availability of additional diagnostic tools. RT-QuIC assays allow ultrasensitive detection of prion seeds in a wide variety of cervid tissues, fluids and excreta. The best documented antemortem diagnostic test involvin...

Creutzfeldt–Jakob Disease (CJD) is a fatal, currently incurable, neurodegenerative disease. The search for candidate treatments would be greatly facilitated by the availability of human cell-based models of prion disease. Recently, an induced pluripotent stem cell derived human cerebral organoid model was shown to take up and propagate human CJD pr...

Classical mammalian prions are assemblies of prion protein molecules that are extraordinarily transmissible, with a microgram of protein containing up to 10^8 lethal doses of infectivity1,2. Unlike most other pathogenic and amyloidogenic proteins, prions typically contain glycolipid anchors 3 and abundant asparagine-linked glycans4-6. The infectiou...

Background Assays that specifically measure α‐synuclein seeding activity in biological fluids could revolutionize the diagnosis of Parkinson’s disease. Recent improvements in α‐synuclein real‐time quaking‐induced conversion assays of cerebrospinal fluid have dramatically reduced reaction times from 5‐13 days down to 1‐2 days. Objective To test our...

Objective Real‐time quaking‐induced conversion (RT‐QuIC) assays detect prion‐seeding activity in a variety of human biospecimens, including cerebrospinal fluid and olfactory mucosa swabs. The assay has shown high diagnostic accuracy in patients with prion disorders. Recently, advances in these tests have led to markedly improved diagnostic sensitiv...

An amendment to this paper has been published and can be accessed via the original article.

he article Ultrasensitive RT‑QuIC assay with high sensitivity and specificity for Lewy body‑.

The clinical diagnosis of synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), is challenging, especially at an early disease stage, due to the heterogeneous and often non-specific clinical manifestations. The discovery of reliable specific markers for synucleinopathies would con...

Objective The detection of prion seeding activity in CSF and olfactory mucosal brushings using real‐time quaking‐induced conversion assays allows highly accurate clinical diagnosis of sporadic Creutzfeldt–Jakob disease. To gauge transmission risks associated with these biospecimens and their testing, we have bioassayed prion infectivity levels in p...

Supplementary material for: Million-fold sensitivity enhancement in proteopathic seed amplification assays for biospecimens by Hofmeister ion comparisons

Significance Detection of aggregated proteins in human tissues represents a challenging, yet proven, avenue for diagnosing neurodegenerative diseases. For therapeutic advances to occur, an accurate and early diagnosis must be made, which would ideally rely on a biomarker that can track the progression of the disease. One challenging aspect to this...

Chronic wasting disease (CWD) is a fatal prion disease that can infect deer, elk and moose. CWD has now been detected in 26 states of the USA, 3 Canadian provinces, South Korea, Norway, Sweden and Finland. CWD continues to spread from endemic areas, and new foci of infections are frequently detected. As increasing numbers of cervids become infected...

Chronic wasting disease (CWD) is a fatal prion disease which affects cervids. This disease has an asymptomatic incubation time of 2-4 years, and during this period cervids can shed prions through saliva, feces, urine and placental tissue, contaminating the environment. Indeed, CWD is highly contagious between cervids and shedding from live, infecte...

The abnormal assembly of tau, α-synuclein (αSyn), or prion protein into oligomers and multimers underpins the molecular pathogenesis of multiple neurodegenerative diseases. Such pathological aggregates can often grow by seeded polymerization mechanisms. We and others have taken advantage of these mechanisms to amplify seeding activities in vitro an...

Chronic wasting disease (CWD) is a fatal prion disease found in deer, elk, and moose. Since it was first discovered in the late 1960s, CWD has now spread to at least 25 U.S. states, 2 Canadian provinces, South Korea, Norway, and Finland. Eradication of CWD from areas of endemicity is very unlikely, and additional spread will occur. As the range and...

Human familial prion diseases are associated with mutations at 34 different prion protein (PrP) amino acid residues. However, it is unclear whether infectious prions are found in all cases. Mutant PrP itself may be neurotoxic, or alternatively, PrP mutation might predispose to spontaneous formation of infectious PrP isoforms. Previous reports demon...

The diagnosis and treatment of synucleinopathies such as Parkinson disease and dementia with Lewy bodies would be aided by the availability of assays for the pathogenic disease-associated forms of α-synuclein (αSynD) that are sufficiently sensitive, specific, and practical for analysis of accessible diagnostic specimens. Two recent αSynD seed ampli...

Accumulation of fibrillar protein aggregates is a hallmark of many diseases. While numerous proteins form fibrils by prion-like seeded polymerization in vitro, only some are transmissible and pathogenic in vivo. To probe the structural features that confer transmissibility to prion protein (PrP) fibrils, we have analyzed synthetic PrP amyloids with...

Mammalian prion structures and replication mechanisms are poorly understood. Most synthetic recombinant prion protein (rPrP) amyloids prepared without cofactors are non-infectious or much less infectious than bona fide tissue-derived PrPSc. This effect has been associated with differences in folding of the aggregates, manifested in part by reduced...

End-point dilution RT-QuIC analysis of the brains from P1 animals. Representative end-point dilution RT-QuIC analysis of brain homogenates from hamsters (A [A465-1] & B [A458-2]) and Tg7 mice (C [B991-1] & D [B987-3]) inoculated with ScBH(WT)RTQ (A & C) or ScBH(K4N)RTQ (B & D). Hamsters were assayed at 10−3–10−7 brain tissue dilutions and Tg7 mice...

Histopathology of brain samples from a control Tg7 mouse inoculated with ScBH. Brain regions affected in ScBH(PrPSen)P1 as well as areas commonly affected by 263K scrapie are displayed. Slides were stained using a PrP antibody (EP1802Y), anti-GFAP antibody, or hematoxylin and eosin. Scale bar indicates 50 microns. (TIF)

Summary of histopathology results. The table describes the histopathology as it pertains to spongiosis, astrogliosis and PrP deposition for each ScBH animal. (PDF)

Epitope mapping of newly formed PrPRes in brains from ScBH(WT or K4N)P1 Tg7 mice. PrP antibodies R30 (A; epitope: 89–103), 3F4 (B; epitope: 109–112), mAB132 (C; epitope: 119–127), R18 (D; epitope: 143–156), and R20 (E; epitope: 218–231) were used. (F) Diagram outlining the location of antibody epitopes. The locations of the central lysine cluster (...

Histopathology of the hippocampus of Tg7 ScBH(WT or K4N)P2 and control mice. A comparison between ScBH(K4N)P2 Tg7 mice that had acute TSE disease at 143 dpi and ScBH(K4N)P2 Tg7 mice that had a prolonged clinical course out to 433 dpi is shown. Red arrow heads denote PrP aggregates and black arrow heads denote vacuolization (spongiosis). Slides were...

Summary of all results for each animal. The table summarizes the individual animal data for A) Hamsters, B) Tg7 P1 mice, and C) Tg7 P2 mice. (XLSX)

Histopathology of the hippocampus of Tg7 ScBH(WT or K4N)P1 mice and controls. Slides were stained using a PrP antibody (EP1802Y), GFAP antibody, or hematoxylin and eosin. Animal numbers are displayed below images. Red arrow heads denote PrP aggregates and black arrows denote vacuolization (spongiosis). Scale bar indicates 50 microns. (TIF)

End-point dilution RT-QuIC analysis of inocula. Representative RT-QuIC profiles of ScBH(WT)RTQ product (top left), ScBH(K4N)RTQ product (top right), NBH(WT)RTQ product (bottom left), and NBH(K4N)RTQ product (bottom right). Each sample was serially diluted down to 10−9 sample dilutions. Each trace is an average of four replicate wells. The SD50 per...

End-point dilution RT-QuIC analysis of the brains from P2 animals. Representative end-point dilution RT-QuIC analysis of one ScBH(WT)P2 brain homogenate (A [C204-2]) and one ScBH(K4N)P2 brain homogenate (B [C208-2]). Each sample was assayed down to 10−10 brain tissue dilutions. SD50 per mg of brain homogenate is displayed above each panel. The anim...

An early and accurate in vivo diagnosis of rapidly progressive dementia remains challenging, despite its critical importance for the outcome of treatable forms, and the formulation of prognosis. Real-Time Quaking-Induced Conversion (RT-QuIC) is an in vitro assay that, for the first time, specifically discriminates patients with prion disease. Here,...

In coping with prion diseases, it is important to have tests that are practical enough for routine applications in medicine, agriculture, wildlife biology, and research, yet sensitive enough to detect minimal amounts of infectivity. Real-time quaking-induced conversion (RT-QuIC) assays have evolved to the point where they fulfill these criteria in...

Until recently, it has been difficult to detect all infectious levels of prions and diagnose prion diseases in living humans and other animals. Real-time quaking-induced conversion (RT-QuIC), an ultrasensitive test based on amplification of the amyloid seeding activity of prions, is now achieving the sensitivity and practicality required for routin...

Among the most sensitive, specific and practical of methods for detecting prions are the real-time quaking-induced conversion (RT-QuIC) assays. These assays exploit the fundamental self-propagating activity of prions to amplify the presence of prion seeds by as much as a trillion-fold. The reactions can detect most of the known mammalian prion dise...

Importance: Mechanisms of prion propagation, and what makes them transmissible, are poorly understood. Glycosylphosphatidylinositol (GPI) membrane anchoring of the prion protein (PrP(C)) directs it to specific regions of cell membranes called rafts. In order to test the importance of the raft environment on prion propagation, we developed a novel...

Table S1. Patient Demographic information. Yellow shading indicates patients who tested negative by both PQ‐ and IQ‐CSF conditions.

Importance: Early and accurate in vivo diagnosis of Creutzfeldt-Jakob disease (CJD) is necessary for quickly distinguishing treatable from untreatable rapidly progressive dementias and for future therapeutic trials. This early diagnosis is becoming possible using the real-time quaking-induced conversion (RT-QuIC) seeding assay, which detects minut...

Real-Time Quaking-Induced Conversion (RT-QuIC) testing of human cerebrospinal fluid (CSF) is highly sensitive and specific in discriminating sporadic CJD patients from those without prion disease. Here, using CSF samples from 113 CJD and 64 non-prion disease patients, we provide the first direct and concurrent comparison of our improved RT-QuIC ass...

Hypochlorous acid (HOCl) is produced naturally by neutrophils and other cells to kill conventional microbes in vivo. Synthetic preparations containing HOCl can also be effective as microbial disinfectants. Here we have tested whether HOCl can also inactivate prions and other self-propagating protein amyloid seeds. Prions are deadly pathogens that a...

RT-QuIC seeding activity tolerance for BrioHOCl. RT-QuIC analysis was performed with Hamster (90–231) recombinant prion protein substrate at 42°C using 2μl per well of normal brain homogenate (gray) or hamster scrapie brain homogenate at a tissue dilution of 5x10-8 as reaction seed in the presence of 0 (red) or 0.001, 0.01, 0.1, 1 & 10% BrioHOCl (b...

Tolerance of α-synuclein RT-QuIC assay for BrioHOCl. Direct addition of BrioHOCl to α-synuclein RT-QuIC reactions seeded with a 10-2 dilution of an artificial α-syn seed. While direct addition of the equivalent to a 10-2 dilution (1.8% HOCl, blue line) partially interfered with the reaction (compared to the no HOCl control, orange line), 10-3 (0.18...

Raman spectroscopy of BrioHOCl. (DOCX)

Antimicrobial efficacy of BrioHOCl in ASTM E2315 Time vs. Kill suspension test protocol using lot samples of different ages. (DOCX)

The real-time quaking-induced conversion (RT-QuIC) is a rapid, specific, and highly sensitive prion seeding activity detection assay that uses recombinant prion protein (rPrPSen) to detect sub-infectious levels of the abnormal isoforms of the prion protein (PrPSc). Although RT-QuIC has been successfully used to detect PrPSc in various tissues from...