Béta-amiloid peptidek aggregációja és kölcsönhatása fehérjékkel; új neuroprotektív vegyületek alkalmazása az Alzheimer-kór megelőzésére = Beta-amyloid aggregation and interaction with proteins; novel neuroprotective compounds for prevention of Alzheimer's disease

Új, standardizálható módszert dolgoztunk ki toxikus �béta-amiloid (Abéta) 1-42 peptid oligomerek előállítására, a preparált oligomereket fiziko-kémiai módszerekkel jellemeztük. Két új neuroprotektív peptidmimetikum vegyületcsaládot találtunk, ezek az anyagok megvédik a neuronokat az Alzheimer-kór (AK) állatmodelljében az Abéta neurotoxikus hatásától. Mindkét vegyületcsoportot szabadalmilag védjük, mint az AK potenciális gyógyszerjelölt vegyületeit. Új ex vivo módszert dolgoztunk ki az Abéta peptidek toxicitásának mérésére (patkány hippocampus szelet, MTT-teszt), a módszer alkalmas az új neuroprotektív vegyületeink aktivitásmérésére is. Az ex vivo hippocampus szeleteket sikerrel alkalmaztuk a neuronális plaszticitás (LTP) mérésére, az Abéta-toxicitás meghatározására, multielektród array (MEA) technikával. In vivo, egysejt-elvezetéses elektrofiziológiai mérésekkel bizonyítottuk az új peptidmimetikumaink neuroprotektív hatását. Proteomikai módszerekkel azonosítottuk az Abéta peptidekkel kölcsönhatásba lépő fehérjéket, ezek elsősorban plazmamembrán, ill. intraneuronális fehérjék (mitokondrium, endoplazmás reticulum, mikrotubuláris rendszer). Az intraneuronális fehérjék és az Abéta peptidek kölcsönhatásai kulcsszerepet játszhatnak az AK patogenezisében. Igazoltuk, hogy a Zn2+ ionok toxikus Abéta-aggregátumok képződését indukálják. Az AK transzgén állatmodelljén bizonyítottuk, hogy a Zn-kelátorok (pl. Perindopril) neuroprotektív hatásúak. Új AK-állatmodellt dolgoztunk ki az Abéta oligomerek icv bevitelével. | A new method was introduced for the preparation of toxic beta-amyloid (Abeta) 1-42 oligomers, these assemblies were characterized with physicochemical methods. Two families of novel neuroprotective peptidomimetics were found, these substances protect neurons against the toxic effect of Abeta in tg mouse models of Alzheimer’s disease (AD). Both groups of the novel substances will be patented as putative drug candidates for AD treatment. A new ex vivo method was introduced for toxicity measurement of Abeta peptides (rat hippocampal slices, MTT-assay); this method proved to be suitable for activity measurement of the novel neuroprotective substances. Hippocampal slices were successfully used for measurement of neuronal plasticity (LTP) for demonstrating neurotoxicity of Abeta aggregates, applying multielectrode array (MEA) technique. The neuroprotective effect of our novel peptidomimetics was demonstrated also in vivo, using one-cell electrophysiology. Proteomic methods were used for identification of proteins interacting with Abeta peptides; these are mainly plasma membrane and intraneuronal (mitochondrial, endoplasmatic reticular and microtubular) proteins. Interaction of intracellular proteins with Abeta may play key role in AD pathogenesis. The role of Zn2+ ions in formation of toxic Abeta-aggregates was demonstrated. Zn2+-chelators (e.g. Perindopril) were neuroprotective in a tg-mouse model of AD. A new AD rat model was introduced using icv administration of synthetic Abeta oligomers

A qPCR-based, population dynamics approach for the development of a bacteriophage-based biopesticide

Bacteriophages are viruses that target specific bacteria and kill them through their own replicative life cycle. As more countries ban the use of antibiotics for the control of fire blight and antibiotic resistant strains of Erwinia amylovora become more widespread, the use of phages as biological control agents is rapidly gaining interest. In the multinational Horizon 2020 Project PhageFire, several academic and industry partners have teamed up to develop a phage-based product for the control of fire blight. To design an effective and affordable phage formulation, the choice of phages in the cocktail is critical. The ultimate goal is to maximize synergistic interactions and minimize antagonistic interactions between the different phages while using the fewest number of phages possible to reduce production costs. To achieve this goal, we used a quantitative real-time PCR (qPCR) approach to study different combinations of a collection of phages against a combined library of E. amylovora strains representative of the pathogen diversity in Europe. With qPCR, the populations of the phages and E. amylovora can be measured individually over time in liquid cultures. This allows us to determine which phages synergize best together, while eliminating those that get outcompeted and add little overall value to the cocktail. With this work, in conjunction with additional product formulation, regulatory efforts, and field trials we aim to develop an effective, affordable, phage-based biopesticide for the control of fire blight

PhageFire : formulation of a bacteriophage-based biopesticide against Erwinia amylovora

Many plant protection agents traditionally used to combat fire blight are subjected to restrictions in an increasing number of countries. The emergence of streptomycin-resistant bacteria has called for antibiotic-free alternatives, while the use of aluminum- and copper-based products has raised environmental concerns. In this scope, there is a high demand for alternative products with lower risk profiles, for example antagonistic bacteria, yeasts, or bacteriophages (phages). Phages are considered safe for both the environment and human health, and they are highly specific for their target bacterium. Some phage-based agents have already been approved for use in plant protection and food safety. However, diverse environmental factors can impair the phages’ stability. UV-light, for example, which is damaging to DNA, can inactivate phages in the field. In the European Horizon 2020 project PhageFire, the goal of all involved partners is to develop such a phage-based biopesticide against fire blight. Here, we tested different UV-B absorbing substances and surfactants to develop an effective formulation to protect the bacteriophages from UV-B light and to ensure an even foliage coverage and adherence of the phages to the plant surface. Under artificial UV-B illumination, the phages’ survival could be increased by the addition of UV-B absorbents. We could also show that many commercially available surfactants are compatible with phages and do not affect their stability. With these contributions, complemented by phage characterization, field trials, and regulatory aspects, we aim to develop an effective and safe biopesticide against fire blight