scholarly journals Gene-Based Antibody Strategies for Prion Diseases

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Alessio Cardinale ◽  
Silvia Biocca
Keyword(s):  
Therapeutic Potential ◽  
Prion Diseases ◽  
Recombinant Antibody ◽  
Cellular Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Diagnostic Tools ◽  
Spongiform Encephalopathies ◽  
Interaction Sites

Prion diseases or transmissible spongiform encephalopathies (TSE) are a group of neurodegenerative and infectious disorders characterized by the conversion of a normal cellular protein PrPCinto a pathological abnormally folded form, termed PrPSc. There are neither available therapies nor diagnostic tools for an early identification of individuals affected by these diseases. New gene-based antibody strategies are emerging as valuable therapeutic tools. Among these, intrabodies are chimeric molecules composed by recombinant antibody fragments fused to intracellular trafficking sequences, aimed at inhibiting,in vivo, the function of specific therapeutic targets. The advantage of intrabodies is that they can be selected against a precise epitope of target proteins, including protein-protein interaction sites and cytotoxic conformers (i.e., oligomeric and fibrillar assemblies). Herein, we address and discussin vitroandin vivoapplications of intrabodies in prion diseases, focussing on their therapeutic potential.

scholarly journals Prion Disease Blood Test Using Immunoprecipitation and Improved Quaking-Induced Conversion

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Christina D. Orrú ◽  
Jason M. Wilham ◽  
Lynne D. Raymond ◽  
Franziska Kuhn ◽  
Björn Schroeder ◽  
...  
Keyword(s):  
Real Time ◽  
Blood Test ◽  
Prion Diseases ◽  
Proteinase K ◽  
Transmissible Spongiform Encephalopathies ◽  
Serum Samples ◽  
Spongiform Encephalopathies ◽  
Jakob Disease

ABSTRACT A key challenge in managing transmissible spongiform encephalopathies (TSEs) or prion diseases in medicine, agriculture, and wildlife biology is the development of practical tests for prions that are at or below infectious levels. Of particular interest are tests capable of detecting prions in blood components such as plasma, but blood typically has extremely low prion concentrations and contains inhibitors of the most sensitive prion tests. One of the latter tests is quaking-induced conversion (QuIC), which can be as sensitive as in vivo bioassays, but much more rapid, higher throughput, and less expensive. Now we have integrated antibody 15B3-based immunoprecipitation with QuIC reactions to increase sensitivity and isolate prions from inhibitors such as those in plasma samples. Coupling of immunoprecipitation and an improved real-time QuIC reaction dramatically enhanced detection of variant Creutzfeldt-Jakob disease (vCJD) brain tissue diluted into human plasma. Dilutions of 1014-fold, containing ~2 attogram (ag) per ml of proteinase K-resistant prion protein, were readily detected, indicating ~10,000-fold greater sensitivity for vCJD brain than has previously been reported. We also discriminated between plasma and serum samples from scrapie-infected and uninfected hamsters, even in early preclinical stages. This combined assay, which we call “enhanced QuIC” (eQuIC), markedly improves prospects for routine detection of low levels of prions in tissues, fluids, or environmental samples. IMPORTANCE Transmissible spongiform encephalopathies (TSEs) are largely untreatable and are difficult to diagnose definitively prior to irreversible clinical decline or death. The transmissibility of TSEs within and between species highlights the need for practical tests for even the smallest amounts of infectivity. A few sufficiently sensitive in vitro methods have been reported, but most have major limitations that would preclude their use in routine diagnostic or screening applications. Our new assay improves the outlook for such critical applications. We focused initially on blood plasma because a practical blood test for prions would be especially valuable for TSE diagnostics and risk reduction. Variant Creutzfeldt-Jakob disease (vCJD) in particular has been transmitted between humans via blood transfusions. Enhanced real-time quaking-induced conversion (eRTQ) provides by far the most sensitive detection of vCJD to date. The 15B3 antibody binds prions of multiple species, suggesting that our assay may be useful for clinical and fundamental studies of a variety of TSEs of humans and animals.

scholarly journals Cells Expressing Anchorless Prion Protein Are Resistant to Scrapie Infection

2009 ◽  
Vol 83 (9) ◽  
pp. 4469-4475 ◽  
Author(s):  
Kristin L. McNally ◽  
Anne E. Ward ◽  
Suzette A. Priola
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Prion Diseases ◽  
Transmitted Disease ◽  
Transmissible Spongiform Encephalopathies ◽  
Gpi Anchor ◽  
Spongiform Encephalopathies ◽  
Infected Cells

ABSTRACT The hallmark of transmissible spongiform encephalopathies (TSEs or prion diseases) is the accumulation of an abnormally folded, partially protease-resistant form (PrP-res) of the normal protease-sensitive prion protein (PrP-sen). PrP-sen is attached to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. In vitro, the anchor and the local membrane environment are important for the conversion of PrP-sen to PrP-res. In vivo, however, the anchor is not necessary because transgenic mice expressing anchorless PrP-sen accumulate PrP-res and replicate infectivity. To clarify the role of the GPI anchor in TSE infection, cells expressing GPI-anchored PrP-sen, anchorless PrP-sen, or both forms of PrP-sen were exposed to the mouse scrapie strain 22L. Cells expressing anchored PrP-sen produced PrP-res after exposure to 22L. Surprisingly, while cells expressing anchorless PrP-sen made anchorless PrP-res in the first 96 h postinfection, no PrP-res was detected at later passes. In contrast, when cells expressing both forms of PrP-sen were exposed to 22L, both anchored and anchorless PrP-res were detected over multiple passes. Consistent with the in vitro data, scrapie-infected cells expressing anchored PrP-sen transmitted disease to mice whereas cells expressing anchorless PrP-sen alone did not. These results demonstrate that the GPI anchor on PrP-sen is important for the persistent infection of cells in vitro. Our data suggest that cells expressing anchorless PrP-sen are not directly infected with scrapie. Thus, PrP-res formation in transgenic mice expressing anchorless PrP-sen may be occurring extracellularly.

scholarly journals Detection of Pathognomonic Biomarker PrPSc and the Contribution of Cell Free-Amplification Techniques to the Diagnosis of Prion Diseases

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 469
Author(s):  
Hasier Eraña ◽  
Jorge M. Charco ◽  
Ezequiel González-Miranda ◽  
Sandra García-Martínez ◽  
Rafael López-Moreno ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Immunohistochemical Analysis ◽  
Body Fluids ◽  
Detection Methods ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathies ◽  
Prion Propagation

Transmissible spongiform encephalopathies or prion diseases are rapidly progressive neurodegenerative diseases, the clinical manifestation of which can resemble other promptly evolving neurological maladies. Therefore, the unequivocal ante-mortem diagnosis is highly challenging and was only possible by histopathological and immunohistochemical analysis of the brain at necropsy. Although surrogate biomarkers of neurological damage have become invaluable to complement clinical data and provide more accurate diagnostics at early stages, other neurodegenerative diseases show similar alterations hindering the differential diagnosis. To solve that, the detection of the pathognomonic biomarker of disease, PrPSc, the aberrantly folded isoform of the prion protein, could be used. However, the amounts in easily accessible tissues or body fluids at pre-clinical or early clinical stages are extremely low for the standard detection methods. The solution comes from the recent development of in vitro prion propagation techniques, such as Protein Misfolding Cyclic Amplification (PMCA) and Real Time-Quaking Induced Conversion (RT-QuIC), which have been already applied to detect minute amounts of PrPSc in different matrixes and make early diagnosis of prion diseases feasible in a near future. Herein, the most relevant tissues and body fluids in which PrPSc has been detected in animals and humans are being reviewed, especially those in which cell-free prion propagation systems have been used with diagnostic purposes.

scholarly journals Prion protein interconversions†

2001 ◽  
Vol 356 (1406) ◽  
pp. 197-202 ◽  
Author(s):  
Byron Caughey
Keyword(s):  
Neurodegenerative Diseases ◽  
Prion Protein ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathies ◽  
Biological Parameters ◽  
Spongiform Encephalopathies ◽  
Lead Compounds ◽  
Resistant Form

The transmissible spongiform encephalopathies (TSEs), or prion diseases, remain mysterious neurodegenerative diseases that involve perturbations in prion protein (PrP) structure. This article summarizes our use of in vitro models to describe how PrP is converted to the disease–associated, protease–resistant form. These models reflect many important biological parameters of TSE diseases and have been used to identify inhibitors of the PrP conversion as lead compounds in the development of anti–TSE drugs.

scholarly journals Neuroprotective role of PrPC against kainate-induced epileptic seizures and cell death depends on the modulation of JNK3 activation by GluR6/7–PSD-95 binding

2011 ◽  
Vol 22 (17) ◽  
pp. 3041-3054 ◽  
Author(s):  
Patricia Carulla ◽  
Ana Bribián ◽  
Alejandra Rangel ◽  
Rosalina Gavín ◽  
Isidro Ferrer ◽  
...  
Keyword(s):  
Prion Protein ◽  
Knockout Mice ◽  
Neuronal Excitability ◽  
Epileptic Seizures ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathies ◽  
Glycosyl Phosphatidylinositol

Cellular prion protein (PrPC) is a glycosyl-phosphatidylinositol–anchored glycoprotein. When mutated or misfolded, the pathogenic form (PrPSC) induces transmissible spongiform encephalopathies. In contrast, PrPC has a number of physiological functions in several neural processes. Several lines of evidence implicate PrPC in synaptic transmission and neuroprotection since its absence results in an increase in neuronal excitability and enhanced excitotoxicity in vitro and in vivo. Furthermore, PrPC has been implicated in the inhibition of N-methyl-d-aspartic acid (NMDA)–mediated neurotransmission, and prion protein gene (Prnp) knockout mice show enhanced neuronal death in response to NMDA and kainate (KA). In this study, we demonstrate that neurotoxicity induced by KA in Prnp knockout mice depends on the c-Jun N-terminal kinase 3 (JNK3) pathway since Prnpo/oJnk3o/o mice were not affected by KA. Pharmacological blockage of JNK3 activity impaired PrPC-dependent neurotoxicity. Furthermore, our results indicate that JNK3 activation depends on the interaction of PrPC with postsynaptic density 95 protein (PSD-95) and glutamate receptor 6/7 (GluR6/7). Indeed, GluR6–PSD-95 interaction after KA injections was favored by the absence of PrPC. Finally, neurotoxicity in Prnp knockout mice was reversed by an AMPA/KA inhibitor (6,7-dinitroquinoxaline-2,3-dione) and the GluR6 antagonist NS-102. We conclude that the protection afforded by PrPC against KA is due to its ability to modulate GluR6/7-mediated neurotransmission and hence JNK3 activation.

scholarly journals Toxicological Evaluation of Anti-Scrapie Trimethoxychalcones and Oxadiazoles

2015 ◽  
Vol 87 (2 suppl) ◽  
pp. 1421-1434 ◽  
Author(s):  
CLAUDIA P. FIGUEIREDO ◽  
NATALIA C. FERREIRA ◽  
GISELLE F. PASSOS ◽  
ROBSON DA COSTA ◽  
FERNANDA S. NEVES ◽  
...  
Keyword(s):  
Prion Protein ◽  
Aromatic Compounds ◽  
Prion Diseases ◽  
Intraperitoneal Administration ◽  
Neuroblastoma Cells ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Toxicological Evaluation ◽  
Spongiform Encephalopathies

An altered form of the cellular prion protein, the PrPScor PrPRes, is implicated in the occurrence of the still untreatable transmissible spongiform encephalopathies. We have previously synthesized and characterized aromatic compounds that inhibit protease-resistant prion protein (PrPRes) accumulation in scrapie-infected cells. These compounds belong to different chemical classes, including acylhydrazones, chalcones and oxadiazoles. Some of the active compounds were non-toxic to neuroblastoma cells in culture and seem to possess drugable properties, since they are in agreement with the Lipinski´s rule of 5 and present desirable pharmacokinetic profiles as predicted in silico. Before the evaluation of the in vivo efficacy of the aromatic compounds in scrapie-infected mice, safety assessment in healthy mice is needed. Here we used Swiss mice to evaluate the acute toxicity profile of the six most promising anti-prionic compounds, the 2,4,5-trimethoxychalcones (J1, J8, J20 and J35) and the 1,3,4-oxadiazoles (Y13 and Y17). One single oral administration (300 mg/kg) of J1, J8, J20, J35, Y13 and Y17 or repeated intraperitoneal administration (10 mg/kg, 3 times a week, for 4 weeks) of J1, J8 and J35, did not elicit toxicity in mice. We strongly believe that the investigated trimethoxychalcones and oxadiazoles are interesting compounds to be further analyzed in vivo against prion diseases.

scholarly journals Development of antibody fragments for immunotherapy of prion diseases

2009 ◽  
Vol 418 (3) ◽  
pp. 507-515 ◽  
Author(s):  
Vincenza Campana ◽  
Lorena Zentilin ◽  
Ilaria Mirabile ◽  
Agata Kranjc ◽  
Philippe Casanova ◽  
...  
Keyword(s):  
Structural Model ◽  
Prion Diseases ◽  
Neuronal Cell ◽  
Cellular Protein ◽  
Proteinase K ◽  
Active Immunotherapy ◽  
Transmissible Spongiform Encephalopathies ◽  
Single Chain ◽  
Infected Cells

Prions are infectious proteins responsible for a group of fatal neurodegenerative diseases called TSEs (transmissible spongiform encephalopathies) or prion diseases. In mammals, prions reproduce themselves by recruiting the normal cellular protein PrPC and inducing its conversion into the disease-causing isoform denominated PrPSc. Recently, anti-prion antibodies have been shown to permanently cure prion-infected cells. However, the inability of full-length antibodies and proteins to cross the BBB (blood-brain barrier) hampers their use in the therapy of TSEs in vivo. Alternatively, brain delivery of prion-specific scFv (single-chain variable fragment) by AAV (adeno-associated virus) transfer delays the onset of the disease in infected mice, although protection is not complete. We investigated the anti-prion effects of a recombinant anti-PrP (D18) scFv by direct addition to scrapie-infected cell cultures or by infection with both lentivirus and AAV-transducing vectors. We show that recombinant anti-PrP scFv is able to reduce proteinase K-resistant PrP content in infected cells. In addition, we demonstrate that lentiviruses are more efficient than AAV in gene transfer of the anti-PrP scFv gene and in reducing PrPSc content in infected neuronal cell lines. Finally, we have used a bioinformatic approach to construct a structural model of the D18scFv–PrPC complex. Interestingly, according to the docking results, ArgPrP151 (Arg151 from prion protein) is the key residue for the interactions with D18scFv, anchoring the PrPC to the cavity of the antibody. Taken together, these results indicate that combined passive and active immunotherapy targeting PrP might be promising strategies for therapeutic intervention in prion diseases.

Prion protein as a target for therapeutic interventions

2004 ◽  
Vol 76 (5) ◽  
pp. 915-920 ◽  
Author(s):  
P. P. Liberski
Keyword(s):  
Prion Protein ◽  
Phenotypic Expression ◽  
Therapeutic Interventions ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Public Health Perspective ◽  
Spongiform Encephalopathies ◽  
Mad Cow Disease

Transmissible spongiform encephalopathies (TSEs), currently known as prion diseases, are neurodegenerative disorders of the central nervous system (CNS) caused by an elusive infectious agent called “prion” (proteinaceous infectious particle). These dis orders include: kuru, Creutzfeldt –Jakob disease (CJD) and its variant (vCJD), Gerstmann–Sträussler–Scheinker (GSS) disease and fatal familial insomnia (FFI) in humans, scrapie in sheep and goats, bovine spongiform encephalopathy (BSE) or mad cow disease, and chronic wasting disease (CWD) in cervids. According to the widely accepted “prion hypothesis”, prion is an aggregate of the abnormal isoform of prion protein (PrPSc). Prion protein is a cell-derived glycoprotein (this normal isoform is called PrPc) encoded by a gene on chromosome 20 in humans (PRNP). In familial forms of TSEs, mutations within the ORF of PRNP are linked to the phenotypic expression of the disease. TSEs are important from public health perspective, and “mad cow disease has created the greatest threat to the safety of human food supply in modern times. vCJD threatens the safety of the blood supply worldwide”. Thus, to search for effective therapy is more than an urgent task. In TSEs, aggregates of PrPSc accumulate in the brain in a form of plaques, or synaptic deposits. The conversion of PrPc into PrPSc and subsequent deposits of PrPSc are targets for therapeutic interventions. These include: tricyclic compounds—acridine and phenothiazine derivatives; quinacrine; anti-PrPSc antibodies; dendrimers; polyethylene antibiotics (amphotericin B, MS-8209); pentosan polysulfate; and dextran sulfate. All these compounds are active in many in vitro and in vivo assays, but not proved definitely active in humans. Thus, albeit interesting and promising, the chemotherapy of TSEs is still in the infant phase.

scholarly journals Cerebrospinal Fluid and Plasma Small Extracellular Vesicles and miRNAs as Biomarkers for Prion Diseases

2021 ◽  
Vol 22 (13) ◽  
pp. 6822
Author(s):  
Óscar López-Pérez ◽  
David Sanz-Rubio ◽  
Adelaida Hernaiz ◽  
Marina Betancor ◽  
Alicia Otero ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Clinical Stage ◽  
Proteinase K ◽  
Transmissible Spongiform Encephalopathies ◽  
Alternative Source ◽  
Spongiform Encephalopathies ◽  
In Vivo Diagnosis

Diagnosis of transmissible spongiform encephalopathies (TSEs), or prion diseases, is based on the detection of proteinase K (PK)-resistant PrPSc in post-mortem tissues as indication of infection and disease. Since PrPSc detection is not considered a reliable method for in vivo diagnosis in most TSEs, it is of crucial importance to identify an alternative source of biomarkers to provide useful alternatives for current diagnostic methodology. Ovine scrapie is the prototype of TSEs and has been known for a long time. Using this natural model of TSE, we investigated the presence of PrPSc in exosomes derived from plasma and cerebrospinal fluid (CSF) by protein misfolding cyclic amplification (PMCA) and the levels of candidate microRNAs (miRNAs) by quantitative PCR (qPCR). Significant scrapie-associated increase was found for miR-21-5p in plasma-derived but not in CSF-derived exosomes. However, miR-342-3p, miR-146a-5p, miR-128-3p and miR-21-5p displayed higher levels in total CSF from scrapie-infected sheep. The analysis of overexpressed miRNAs in this biofluid, together with plasma exosomal miR-21-5p, could help in scrapie diagnosis once the presence of the disease is suspected. In addition, we found the presence of PrPSc in most CSF-derived exosomes from clinically affected sheep, which may facilitate in vivo diagnosis of prion diseases, at least during the clinical stage.

MiR490's diagnostic capacity was demonstrated in various cancer kinds and diseases, adding to its clinical value

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Targeted Delivery ◽  
Therapeutic Potential ◽  
Molecular Therapy ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Clinical Value ◽  
Cancer Types ◽  
Diagnostic Capacity

This miR‐490 review first illustrates its association with various clinical malignancies and other diseases. Although in various malignancies miR‐490's activities, regulatory mechanisms and targets were revealed, its significance to other illnesses is beginning to be studied. Note that miR‐490 levels are regulated at different levels by transcription factors, epigenetic factors, and ncRNAs, revealing complicated interplay between these components. A system approach that incorporates miR‐490 and its regulatory components will surely help detect critical miR‐490 hub connections that might affect tumor initiation/progression. Furthermore, a number of pharmacological and environmental variables known to cause disease have also been shown to alter miR‐490 levels, showing miR‐490's significant pathogenesis involvement. The fact that miR‐490 levels are strictly regulated and abnormal miR‐490 levels are reported in many cancer types and diseases highlights miR‐490's significance in controlling cell homeostasis.Due to their increased stability, miRNAs are developed as diagnostic agents. MiR‐490's diagnostic capacity was demonstrated in various cancer kinds and diseases, adding to its clinical value. The potential of miR‐490 as a non-invasive biomarker might possibly be studied by measuring patient serum/saliva/urine levels in tissues or body fluids. Furthermore, miR‐490's demonstrated ability to stratify healthy tissue tumor samples may aid establishing molecular diagnostic tools. In most circumstances, miR‐490's association with improved prognosis is also fascinating. This extra clinical importance makes miR‐490 appropriate for molecular therapy. In most cancer types where miR‐490 has been functionally identified, miR‐490 has been found to be a miRNA tumor suppressor that inhibits several cancer hallmarks by directly controlling oncogenic targets and pathways. In practical practice, a therapy regime using miR‐490 tissue alteration based on rapidly evolving targeted delivery methods may be on the horizon. Nevertheless, further in vivo investigations must be conducted using genetically changed mice models. Although miR‐490 was not yet clinically examined for its therapeutic potential, in vitro and in vivo preclinical experiments revealed enormous promise in translating miR‐490 as a novel therapeutic target. miR‐490 appears as a novel candidate miRNA with significant cancer diagnosis and therapy with its prognostic and diagnostic capabilities. Therefore, miR‐490 might serve as a novel weapon in the current anti-cancer treatment arsenal.

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