scholarly journals In vitro conversion and seeded fibrillization of posttranslationally modified prion protein

2011 ◽  
Vol 392 (5) ◽  
Author(s):  
Jan Stöhr ◽  
Kerstin Elfrink ◽  
Nicole Weinmann ◽  
Holger Wille ◽  
Dieter Willbold ◽  
...  
Keyword(s):  
Prion Protein ◽  
Posttranslational Modifications ◽  
Prion Diseases ◽  
Chinese Hamster Ovary Cells ◽  
Sodium Dodecyl ◽  
Chinese Hamster ◽  
Full Length ◽  
Proteinase K

AbstractThe conversion of the cellular isoform of the prion protein (PrPC) into the pathologic isoform (PrPSc) is the key event in prion diseases. To study the conversion process, anin vitrosystem based on varying the concentration of low amounts of sodium dodecyl sulfate (SDS) has been employed. In the present study, the conversion of full-length PrPCisolated from Chinese hamster ovary cells (CHO-PrPC) was examined. CHO-PrPCharbors native, posttranslational modifications, including the GPI anchor and two N-linked glyco-sylation sites. The properties of CHO-PrPCwere compared with those of full-length and N-terminally truncated recombinant PrP. As shown earlier with recombinant PrP (recPrP90-231), transition from a soluble α-helical state as known for native PrPCinto an aggregated, β-sheet-rich PrPSc-like state could be induced by dilution of SDS. The aggregated state is partially proteinase K (PK)-resistant, exhibiting a cleavage site similar to that found with PrPSc. Compared to recPrP (90-231), fibril formation with CHO-PrPCrequires lower SDS concentrations (0.0075%), and can be drastically accelerated by seeding with PrPScpurified from brain homogenates of terminally sick hamsters. Our results show that recPrP 90-231 and CHO-PrPC behave qualitatively similar but quantitatively different. Thein vivosituation can be simulated closer with CHO-PrPCbecause the specific PK cleave site could be shown and the seed-assisted fibrillization was much more efficient.

scholarly journals Prion Diseases: A Unique Transmissible Agent or a Model for Neurodegenerative Diseases?

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 207
Author(s):  
Diane L. Ritchie ◽  
Marcelo A. Barria
Keyword(s):  
Public Health ◽  
Neurodegenerative Diseases ◽  
Prion Protein ◽  
Neurodegenerative Disorders ◽  
Prion Diseases ◽  
Experimental Models ◽  
Misfolded Proteins ◽  
Current Evidence

The accumulation and propagation in the brain of misfolded proteins is a pathological hallmark shared by many neurodegenerative diseases such as Alzheimer’s disease (Aβ and tau), Parkinson’s disease (α-synuclein), and prion disease (prion protein). Currently, there is no epidemiological evidence to suggest that neurodegenerative disorders are infectious, apart from prion diseases. However, there is an increasing body of evidence from experimental models to suggest that other pathogenic proteins such as Aβ and tau can propagate in vivo and in vitro in a prion-like mechanism, inducing the formation of misfolded protein aggregates such as amyloid plaques and neurofibrillary tangles. Such similarities have raised concerns that misfolded proteins, other than the prion protein, could potentially transmit from person-to-person as rare events after lengthy incubation periods. Such concerns have been heightened following a number of recent reports of the possible inadvertent transmission of Aβ pathology via medical and surgical procedures. This review will provide a historical perspective on the unique transmissible nature of prion diseases, examining their impact on public health and the ongoing concerns raised by this rare group of disorders. Additionally, this review will provide an insight into current evidence supporting the potential transmissibility of other pathogenic proteins associated with more common neurodegenerative disorders and the potential implications for public health.

scholarly journals Evaluation of Fab and F(ab′)2 Fragments and Isotype Variants of a Recombinant Human Monoclonal Antibody against Shiga Toxin 2

2010 ◽  
Vol 78 (3) ◽  
pp. 1376-1382 ◽  
Author(s):  
Donna E. Akiyoshi ◽  
Abhineet S. Sheoran ◽  
Curtis M. Rich ◽  
L. Richard ◽  
Susan Chapman-Bonofiglio ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Shiga Toxin ◽  
Chinese Hamster Ovary Cells ◽  
Human Monoclonal Antibody ◽  
Chinese Hamster ◽  
The Body ◽  
Neutralization Activity ◽  
Shiga Toxin 2

ABSTRACT 5C12 HuMAb is a human monoclonal antibody against the A subunit of Shiga toxin 2 (Stx2). We have previously shown that 5C12 HuMAb effectively neutralizes the cytotoxic effects of this toxin by redirecting its transport within the cell and also by neutralizing the toxin's ability to inhibit protein synthesis. The 5C12 HuMAb and its recombinant IgG1 version protect mice at a dose of 0.6 μg against a lethal challenge of Stx2. The contribution of the Fc region to this observed neutralization activity of the 5C12 antibody against Stx2 was investigated in this study. Using recombinant DNA technology, 5C12 isotype variants (IgG1, IgG2, IgG3, and IgG4) and antibody fragments [Fab, F(ab′)2] were expressed in Chinese hamster ovary cells and evaluated in vitro and in vivo. All four 5C12 isotype variants showed protection in vitro, with the IgG3 and IgG4 variants showing the highest protection in vivo. The Fab and F(ab′)2 fragments also showed protection in vitro but no protection in the mouse toxicity model. Similar results were obtained for a second HuMAb (5H8) against the B subunit of Stx2. The data suggest the importance of the Fc region for neutralization activity, but it is not clear if this is related to the stability of the full-length antibody or if the Fc region is required for effective elimination of the toxin from the body.

scholarly journals PrP P102L and Nearby Lysine Mutations Promote Spontaneous In Vitro Formation of Transmissible Prions

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Allison Kraus ◽  
Gregory J. Raymond ◽  
Brent Race ◽  
Katrina J. Campbell ◽  
Andrew G. Hughson ◽  
...  
Keyword(s):  
Prion Protein ◽  
Prion Diseases ◽  
Transmissible Spongiform Encephalopathy ◽  
Clinical Signs ◽  
Protein Aggregates ◽  
Structural Features ◽  
Spongiform Encephalopathy ◽  
Specific Sequence

ABSTRACT 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 or without the human prion disease-associated P102L mutation. The formation of infectious prions from PrP molecules in vitro has required cofactors and/or unphysiological denaturing conditions. Here, we demonstrate that, under physiologically compatible conditions without cofactors, the P102L mutation in recombinant hamster PrP promoted prion formation when seeded by minute amounts of scrapie prions in vitro. Surprisingly, combination of the P102L mutation with charge-neutralizing substitutions of four nearby lysines promoted spontaneous prion formation. When inoculated into hamsters, both of these types of synthetic prions initiated substantial accumulation of prion seeding activity and protease-resistant PrP without transmissible spongiform encephalopathy (TSE) clinical signs or notable glial activation. Our evidence suggests that PrP's centrally located proline and lysine residues act as conformational switches in the in vitro formation of transmissible PrP amyloids. IMPORTANCE Many diseases involve the damaging accumulation of specific misfolded proteins in thread-like aggregates. These threads (fibrils) are capable of growing on the ends by seeding the refolding and incorporation of the normal form of the given protein. In many cases such aggregates can be infectious and propagate like prions when transmitted from one individual host to another. Some transmitted aggregates can cause fatal disease, as with human iatrogenic prion diseases, while other aggregates appear to be relatively innocuous. The factors that distinguish infectious and pathogenic protein aggregates from more innocuous ones are poorly understood. Here we have compared the combined effects of prion seeding and mutations of prion protein (PrP) on the structure and transmission properties of synthetic PrP aggregates. Our results highlight the influence of specific sequence features in the normally unstructured region of PrP that influence the infectious and neuropathogenic properties of PrP-derived aggregates.

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.

Evaluation of the Toxicity of Intravenous Delivery of Auroshell Particles (Gold–Silica Nanoshells)

2012 ◽  
Vol 31 (6) ◽  
pp. 584-594 ◽  
Author(s):  
Shayne C. Gad ◽  
Kelly L. Sharp ◽  
Charles Montgomery ◽  
J. Donald Payne ◽  
Glenn P. Goodrich
Keyword(s):  
Water Solution ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Gold Nanoshells ◽  
Sprague Dawley ◽  
Ovary Cells ◽  
Good Laboratory ◽  
Chromosomal Aberration Assay

Gold nanoshells (155 nm in diameter with a coating of polyethylene glycol 5000) were evaluated for preclinical biocompatibility, toxicity, and biodistribution as part of a program to develop an injectable device for use in the photothermal ablation of tumors. The evaluation started with a complete good laboratory practice (GLP) compliant International Organization for Standardization (ISO)-10993 biocompatibility program, including cytotoxicity, pyrogenicity (US Pharmacopeia [USP] method in the rabbit), genotoxicity (bacterial mutagenicity, chromosomal aberration assay in Chinese hamster ovary cells, and in vivo mouse micronucleus), in vitro hemolysis, intracutaneous reactivity in the rabbit, sensitization (in the guinea pig maximization assay), and USP/ISO acute systemic toxicity in the mouse. There was no indication of toxicity in any of the studies. Subsequently, nanoshells were evaluated in vivo by intravenous (iv) infusion using a trehalose/water solution in a series of studies in mice, Sprague-Dawley rats, and Beagle dogs to assess toxicity for time durations of up to 404 days. Over the course of 14 GLP studies, the gold nanoshells were well tolerated and, when injected iv, no toxicities or bioincompatibilities were identified.

scholarly journals An Engineered Complement Factor H Construct for Treatment of C3 Glomerulopathy

2018 ◽  
Vol 29 (6) ◽  
pp. 1649-1661 ◽  
Author(s):  
Yi Yang ◽  
Harriet Denton ◽  
Owen R. Davies ◽  
Kate Smith-Jackson ◽  
Heather Kerr ◽  
...  
Keyword(s):  
Chinese Hamster Ovary Cells ◽  
Alternative Pathway ◽  
Treatment Options ◽  
Chinese Hamster ◽  
Factor H ◽  
Complement Factor H ◽  
Complement Factor ◽  
C3 Glomerulopathy

Background C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway of complement activation, and treatment options for C3G remain limited. Complement factor H (FH) is a potent regulator of the alternative pathway and might offer a solution, but the mass and complexity of FH makes generation of full-length FH far from trivial. We previously generated a mini-FH construct, with FH short consensus repeats 1–5 linked to repeats 18–20 (FH1–5^18–20), that was effective in experimental C3G. However, the serum t1/2 of FH1–5^18–20 was significantly shorter than that of serum-purified FH.Methods We introduced the oligomerization domain of human FH-related protein 1 (denoted by R1–2) at the carboxy or amino terminus of human FH1–5^18–20 to generate two homodimeric mini-FH constructs (FHR1–2^1–5^18–20 and FH1–5^18–20^R1–2, respectively) in Chinese hamster ovary cells and tested these constructs using binding, fluid-phase, and erythrocyte lysis assays, followed by experiments in FH-deficient Cfh−/− mice.Results FHR1–2^1–5^18–20 and FH1–5^18–20^R1–2 homodimerized in solution and displayed avid binding profiles on clustered C3b surfaces, particularly FHR1–2^1–5^18–20. Each construct was >10-fold more effective than FH at inhibiting cell surface complement activity in vitro and restricted glomerular basement membrane C3 deposition in vivo significantly better than FH or FH1–5^18–20. FH1–5^18–20^R1–2 had a C3 breakdown fragment binding profile similar to that of FH, a >5-fold increase in serum t1/2 compared with that of FH1–5^18–20, and significantly better retention in the kidney than FH or FH1–5^18–20.Conclusions FH1–5^18–20^R1–2 may have utility as a treatment option for C3G or other complement-mediated diseases.

scholarly journals In vitro and in vivo functional characterization of bovine vitamin K-dependent gamma-carboxylase expressed in Chinese hamster ovary cells.

1993 ◽  
Vol 90 (10) ◽  
pp. 4611-4615 ◽  
Author(s):  
A. Rehemtulla ◽  
D. A. Roth ◽  
L. C. Wasley ◽  
A. Kuliopulos ◽  
C. T. Walsh ◽  
...  
Keyword(s):  
Vitamin K ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Functional Characterization ◽  
Chinese Hamster ◽  
Ovary Cells

scholarly journals Properties of the kinetochore in vitro. I. Microtubule nucleation and tubulin binding.

1985 ◽  
Vol 101 (3) ◽  
pp. 755-765 ◽  
Author(s):  
T J Mitchison ◽  
M W Kirschner
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Lag Phase ◽  
Ovary Cells ◽  
Tubulin Binding ◽  
Mixed Polarity ◽  
Tubulin Immunofluorescence

We have isolated chromosomes from Chinese hamster ovary cells arrested in mitosis with vinblastine and examined the interactions of their kinetochores with purified tubulin in vitro. The kinetochores nucleate microtubule (MT) growth with complex kinetics. After an initial lag phase, MTs are continuously nucleated with both plus and minus ends distally localized. This mixed polarity seems inconsistent with the formation of an ordered, homopolar kinetochore fiber in vivo. As isolated from vinblastine-arrested cells, kinetochores contain no bound tubulin. The kinetochores of chromosomes isolated from colcemid-arrested cells or of chromosomes incubated with tubulin in vitro are brightly stained after anti-tubulin immunofluorescence. This bound tubulin is probably not in the form of MTs. It is localized to the corona region by immunoelectron microscopy, where it may play a role in MT nucleation in vitro.

scholarly journals The pericentriolar material in Chinese hamster ovary cells nucleates microtubule formation

1977 ◽  
Vol 73 (3) ◽  
pp. 601-615 ◽  
Author(s):  
RR Gould ◽  
GG Borisy
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Carbon Coated ◽  
Pericentriolar Material ◽  
And Function

The structure and function of the centrosomes from Chinese hamster ovary (CHO) cells were investigated by electron microscopy of negatively stained wholemount preparations of cell lysates. Cells were trypsinized from culture dishes, lysed with Triton X-100, sedimented onto ionized, carbon-coated grids, and negatively stained with phosphotungstate. The centrosomes from both interphase and dividing cells consisted of pairs of centrioles, a fibrous pericentriolar material, and a group of virus-like particles which were characteristic of the CHO cells and which served as markers for the pericentriolar material. Interphase centrosomes anchored up to two dozen microtubules when cells were lysed under conditions which preserved native microtubules. When Colcemid-blocked mitotic cells, initially devoid of microtubules, were allowed to recover for 10 min, microtubules formed at the pericentriolar material, but not at the centrioles. When lysates of Colcemid-blocked cells were incubated in vitro with micotubule protein purified from porcine brain tissue, up to 250 microtubules assembled at the centrosomes, similar to the number of microtubules that would normally form at the centrosome during cell division. A few microtubules could also be assembled in vitro onto the ends of isolated centrioles from which the pericentriolar material had been removed, forming characteristic axoneme- like bundles. In addition, microtubules; were assembled onto fragments of densely staining, fibrous material which was tentatively identified as periocentriolar material by its association of CHO can initiate and anchor microtubules both in vivo and in vitro.

scholarly journals Ex Vivo and In Vivo CD46 Receptor Utilization by Species D Human Adenovirus Serotype 26 (HAdV26)

2021 ◽  
Author(s):  
Jack R Hemsath ◽  
Manuel Liaci ◽  
Jeffrey Rubin ◽  
Brian Parrett ◽  
Shao-Chia Lu ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Ex Vivo ◽  
Chinese Hamster Ovary Cells ◽  
Ectopic Expression ◽  
Chinese Hamster ◽  
Human Adenovirus ◽  
Adenovirus Serotype ◽  
Cell Counts

Human adenovirus serotype 26 (Ad26) is used as a gene-based vaccine against SARS-CoV-2 and HIV-1. Yet, its primary receptor portfolio remains controversial, potentially including sialic acid, CAR, integrins, and CD46. We and others have shown that Ad26 can use CD46, but these observations were questioned by the inability to co-crystallize Ad26 fiber with CD46. Recent work demonstrated that Ad26 binds CD46 with its hexon protein rather than its fiber. We examined the functional consequences of Ad26 for infection in vitro and in vivo. Ectopic expression of human CD46 on Chinese hamster ovary cells increased Ad26 infection significantly. Deletion of the complement control protein domains CCP1 or CCP2 or the serine-threonine-proline (STP) region of CD46 reduced infection. Comparing wt and sialic acid-deficient CHO cells, we show that the usage of CD46 is independent of its sialylation status. Ad26 transduction was increased in CD46 transgenic mice after intramuscular (IM) injection, but not after intranasal (IN) administration. Ad26 transduction was 10-fold lower than Ad5 after intratumoral (IT) injection of CD46-expressing tumors. Ad26 transduction of liver was 1000-fold lower than Ad5 after intravenous (IV) injection. These data demonstrate the use of CD46 by Ad26 under certain situations, but also show that the receptor has little consequence by other routes of administration. Finally, IV injection of high doses of Ad26 into CD46 mice induced release of liver enzymes in the bloodstream and reduced white blood cell counts, but did not induce thrombocytopenia. This suggests that Ad26 virions do not induce direct clotting side effects seen during COVID-19 vaccination with this serotype of adenovirus.

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