331 research outputs found
„Cztery kamienie to wdzięczność ojczyzny” – pomniki poświęcone poległym żołnierzom versus kultura pamięci w Górnej Austrii od czasów pierwszej wojny światowej do współczesności
Kriegerdenkmäler spiegeln auf besondere Weise sowohl Brüche als auch Kontinuitäten wider, welche die politischen Umwälzungen des Ersten Weltkrieges, des Dritten Reichs sowie der Nachkriegszeit in der österreichischen Erinnerungskultur hinterlassen haben. Dieser Beitrag widmet sich einer Reihe von Denkmälern einer spezifischen Region in Oberösterreich. Die Analyse der Inschriften führt den ambivalenten und oberflächlich neutralen Charakter von Kriegerdenkmälern vor Augen: Deren sprachliche Botschaften lassen zwischen den Extrempolen ‚Helden‘ und ‚Opfer‘ bis heute kaum Platz für gesellschaftlich schonungslose und gleichzeitig historisch reflektierte Perspektiven auf die Gewaltexzesse des 20. Jahrhunderts.War memorials reflect in a special way both the breaks and continuities which the political upheavals of the First World War, the Third Reich and the post-war period left in the Austrian culture of remembrance. In this article, the main focus is on a sample of war memorials in a specific region of Upper Austria. An analysis of the inscriptions shows the ambivalence and superficial neutrality characteristic of war memorials: Their messages based on the extreme poles of ‘heroes’ and ‘victims’, leave little space for socially direct and historically reflective perspectives on the violent excesses of the 20th century.Pomniki poległych odzwierciedlają w szczególny sposób zarówno trwałość jak i niestabilność spuścizny, jaką pozostawiły w austriackiej kulturze pamięci polityczne zawirowania okresu pierwszej wojny światowej, Trzeciej Rzeszy a także okresu po drugiej wojnie światowej. Artykuł poświęcony jest pomnikom specyficznego regionu: Górnej Austrii. Analiza inskrypcji nagrobnych unaocznia zarówno powierzchowność pamięci zbiorowej jak i ambiwalentny charakter pomników poległych żołnierzy. Ich językowe przesłania – nadające żołnierzom ekstremalne funkcje, oscylujące pomiędzy rolą ‘bohaterów’ i ‘ofiar’ – do dnia dzisiejszego nie dopuszczają społecznie koniecznej i jednocześnie historycznie pogłębionej refleksji o zbrodniach XX wieku
Analytical and Bioanalytical Chemistry / Determination of true ratios of different N-glycan structures in electrospray ionization mass spectrometry
Nicht verf\ufcgbarAn ideal method for the analysis of N-glycans would both identify the isomeric structure and deliver a true picture of the relative, if not absolute, amounts of the various structures in one sample. Porous graphitic carbon chromatography coupled with electrospray ionization mass spectrometry (ESI-MS) detection has emerged as a method with a particularly high potential of resolving isomeric oligosaccharides, but little attention has so far been paid to quantitation of the results obtained. In this work, we isolated a range of structures from Man5 to complex type N-glycans with zero to four sialic acids and blended them into an equimolar \u201cglyco tune mix\u201d. When subjected to liquid chromatography\u2013ESI-MS in positive and negative modes, the glyco tune mix clearly demonstrated the futility of quantitation of N-glycans of different overall composition, different number of sialic acids, and strongly differing size without compensation for their very different molar responses. Relative quantitation of human plasma N-glycans was performed with correction factors deduced from this external glyco tune mix. Addition of just one isotope-coded internal standard with enzymatically added 13C-galactose led to absolute quantification in the same experiment
Engineering vacuolar sorting pathways for efficient secretion of recombinant proteins
Recombinant protein production is an expanding branch of biotechnology with increasing economic importance. Currently, 20% of biopharmaceutical proteins and approximately half of the industrial enzymes are produced in yeasts. Many proteins are efficiently secreted by yeast systems, reaching product titers in the g L-1 range. The expression of more complex proteins, however, may overwhelm the folding and secretion capacity of the host cells. This triggers the unfolded protein response (UPR), which aims at restoring endoplasmic reticulum (ER) homeostasis. The UPR, in turn, is thought to activate ER-associated protein degradation (ERAD). Alternatively, trafficking of correctly folded proteins can be hampered on their way to the cell exterior leading e.g. to missorting and subsequent degradation in the vacuole.
The methylotrophic yeast Pichia pastoris (Komagataella spp.) is a popular microbial host for the production of recombinant proteins. Vacuolar protein sorting has not been investigated in detail so far in P. pastoris, although there were a few indications that vacuolar mistargeting of recombinant products might occur also in this yeast. Thus we engineered the vacuolar sorting pathways in P. pastoris and investigated their impact on extracellular product titers as well as intracellular localization of the recombinant secretory product. Thereby, differences between vps (vacuolar protein sorting) mutant strains disrupted in genes involved either in the CORVET or the HOPS tethering complexes became obvious. Moreover, we were able to show that engineering of the vacuolar sorting pathways has a positive impact on heterologous protein secretion, however, in some cases simultaneous inactivation of specific vacuolar proteases was necessary.
Taken together, these studies allowed us to gain deeper insight into the pathways leading to intracellular degradation of recombinant secretory proteins. Based on these findings, approaches how to efficiently adapt the host cell’s secretion capacity will be presented, which confirm that impairment of vacuolar protein sorting is an effective means of enhancing secretion of heterologous proteins
Absolute and relative quantitation of amylase/trypsin-inhibitors by LC-MS/MS from wheat lines obtained by CRISPR-Cas9 and RNAi
Quantitation of wheat proteins is still a challenge, especially regarding amylase/trypsin-inhibitors (ATIs). A selection of ATIs was silenced in the common wheat cultivar Bobwhite and durum wheat cultivar Svevo by RNAi and gene editing, respectively, in order to reduce the amounts of ATIs. The controls and silenced lines were analyzed after digestion to peptides by LC-MS/MS with different approaches to evaluate changes in composition of ATIs. First, a targeted method with stable isotope dilution assay (SIDA) using labeled peptides as internal standards was applied. Additionally, four different approaches for relative quantitation were conducted, in detail, iTRAQ labeled and label free quantitation (LFQ) combined with data dependent acquisition (DDA) and data independent acquisition (DIA). Quantitation was performed manually (Skyline and MASCOT) and with different proteomics software tools (PLGS, MaxQuant, and PEAKS X Pro). To characterize the wheat proteins on protein level, complementary techniques as high-performance liquid chromatography (HPLC) and gel electrophoresis were performed. The targeted approach with SIDA was able to quantitate all ATIs, even at low levels, but an optimized extraction is necessary. The labeled iTRAQ approach revealed an indistinct performance. LFQ with low resolution equipment (IonTrap) showed similar results for major ATIs, but low abundance ATIs as CM1, were not detectable. DDA measurements with an Orbitrap system and evaluation using MaxQuant showed that the relative quantitation was dependent on the wheat species. The combination of manual curation of the MaxQuant search with Skyline revealed a very good performance. The DIA approach with analytical flow found similar results compared to absolute quantitation except for some minor ATIs, which were not detected. Comparison of applied methods revealed that peptide selection is a crucial step for protein quantitation. Wheat proteomics faces challenges due to the high genetic complexity, the close relationship to other cereals and the incomplete, redundant protein database requiring sensitive, precise and accurate LC-MS/MS methods
Characterisation of a highly potent and near pan-neutralising anti-HIV monoclonal antibody expressed in tobacco plants
Background
HIV remains one of the most important health issues worldwide, with almost 40 million people living with HIV. Although patients develop antibodies against the virus, its high mutation rate allows evasion of immune responses. Some patients, however, produce antibodies that are able to bind to, and neutralise different strains of HIV. One such ‘broadly neutralising’ antibody is ‘N6’. Identified in 2016, N6 can neutralise 98% of HIV-1 isolates with a median IC50 of 0.066 µg/mL. This neutralisation breadth makes N6 a very promising therapeutic candidate.
Results
N6 was expressed in a glycoengineered line of N. benthamiana plants (pN6) and compared to the mammalian cell-expressed equivalent (mN6). Expression at 49 mg/kg (fresh leaf tissue) was achieved in plants, although extraction and purification are more challenging than for most plant-expressed antibodies. N-glycoanalysis demonstrated the absence of xylosylation and a reduction in α(1,3)-fucosylation that are typically found in plant glycoproteins. The N6 light chain contains a potential N-glycosylation site, which was modified and displayed more α(1,3)-fucose than the heavy chain. The binding kinetics of pN6 and mN6, measured by surface plasmon resonance, were similar for HIV gp120. pN6 had a tenfold higher affinity for FcγRIIIa, which was reflected in an antibody-dependent cellular cytotoxicity assay, where pN6 induced a more potent response from effector cells than that of mN6. pN6 demonstrated the same potency and breadth of neutralisation as mN6, against a panel of HIV strains.
Conclusions
The successful expression of N6 in tobacco supports the prospect of developing a low-cost, low-tech production platform for a monoclonal antibody cocktail to control HIV in low-to middle income countries
Exploring the Potentiality of a Plant Platform for Monoclonal Antibody Production in Veterinary Medicine
Canine atopic dermatitis (CAD) is an allergic, inflammatory, and pruritic skin disease associated with the production of IgE antibodies against environmental allergens and mainly house dust mite allergens. This complex dermatological pathology involves Interleukin 31 (IL-31) as a central itch mediator. One of the most effective CAD treatments is a caninized monoclonal antibody (mAb) called Lokivetmab. It is produced in CHO cells and targets specifically canine IL-31 (cIL-31) and blocks its cellular messaging. This treatment has undoubtedly contributed to a breakthrough in dermatitis-related pruritus. However, its production in mammalian cells requires time-consuming procedures, high production costs, and investment. Plants are considered an emerging protein production platform for recombinant biopharmaceuticals due to their cost-effectiveness and rapidity for production. Here, we use transient expression in Nicotiana benthamiana plants to produce recombinant canine Interleukin 31 (cIL-31) and an anti-IL-31 monoclonal antibody (M1). First, we describe the production and characterization of M1 and then its activity on an IL-31-induced pruritic model in dogs compared to its commercial homolog. Dogs treated with the plant-made M1 mAb have shown similar improvements to Lokivetmab-treated ones after different challenges using canine IL-31. Furthermore, M1 injections were not associated with any side effects. These results demonstrate the safety and efficacy of this plant-made Lokivetmab biosimilar to control dogs’ pruritus in a well-established model. Finally, this study shows that the plant-production platform can be utilized to produce rapidly functional mAbs and bring hope to the immunotherapy field of veterinary medicine
Shut-down of type IX protein secretion alters the host immune response to Tannerella forsythia and Porphyromonas gingivalis
Tannerella forsythia and Porphyromonas gingivalis target distinct virulence factors bearing a structurally conserved C-terminal domain (CTD) to the type IX protein secretion system (T9SS). The T9SS comprises an outer membrane translocation complex which works in concert with a signal peptidase for CTD cleavage. Among prominent T9SS cargo linked to periodontal diseases are the TfsA and TfsB components of T. forsythia’s cell surface (S-) layer, the bacterium’s BspA surface antigen and a set of cysteine proteinases (gingipains) from P. gingivalis. To assess the overall role of the bacterial T9SS in the host response, human macrophages and human gingival fibroblasts were stimulated with T. forsythia and P. gingivalis wild-type bacteria and T9SS signal peptidase-deficient mutants defective in protein secretion, respectively. The immunostimulatory potential of these bacteria was compared by analyzing the mRNA expression levels of the pro-inflammatory mediators IL-6, IL-8, MCP-1 and TNF- by qPCR and by measuring the production of the corresponding proteins by ELISA. Shot-gun proteomics analysis of T. forsythia and P. gingivalis outer membrane preparations confirmed that several CTD-bearing virulence factors which interact with the human immune system were depleted from the signal peptidase mutants, supportive of effective T9SS shut-down. Three and, more profoundly, 16 hours post stimulation, the T. forsythia T9SS mutant induced significantly less production of cytokines and the chemokine in human cells compared to the corresponding parent strain, while the opposite was observed for the P. gingivalis T9SS mutant. Our data indicate that T9SS shut-down translates into an altered inflammatory response in periodontal pathogens. Thus, the T9SS as a potential novel target for periodontal therapy needs further evaluation
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