Epitópok illetve antimikrobiális hatású peptidek, peptidszármazékok célzott bevitele makrofág típusú sejtekbe = Targeting of epitope or antimicrobial peptides and derivatives to macrophages

A kutatás során számos olyan új vegyület készült el, amelyek segítségével tisztázni lehet epitóp peptidek és hatóanyagok célsejtbe (makrofágba) juttatásának szerkezeti illetve funkcionális feltételeit. Vizsgálataink fontos eredménye olyan biokonjugátumok előállítása volt, amelyekben az alkotórészek a kémiai kötés kialakítása után is megtartották biológiai funkciójukat (pl. T-sejt válasz indukció, ellenanyagfelismerés, antituberkulotikus hatás). A nagyrészt nívós nemzetközi folyóiratokban közölt eredmények közül kiemelkedik annak a jelenségnek a leírása és sokoldalú bizonyítása, amely szerint a makrofágok polianionos szintetikus makromolekulák felvételére scavenger A receptort ?használnak?. Kimutattuk, hogy efféle molekulához kovalensen kapcsolt riporter egység (fluorofor) bekerül a sejtbe. Ez a megfigyelés, valamint a kemotaxis alapú célbajuttatás jelenségének leírása lényegesek lehetnek makromolekulára alapozott célbajuttató rendszerek kifejlesztésében (makromolekula kiválasztás, intracelluláris kötés stabilitás stb.) és segíthetik új gyógyszerek kifejlesztését. | We have prepared a number of new bioconjugates and their components. These compounds proved to be useful for understanding and identification of structural and functional requirements for targeting macrophages. The components of new conjugates prepared preserved their funcional properties (e.g. T cell response provoking capacity, antibody recognition, antituberculotic activity). Among the most important findings we describe that macrophages could internalize polyanionic, synthetic compounds as well as their conjugates. We found that for this purpose scavenger A receptors are utilised. As another important result of the last few years we also proposed and provided experimental evidence concerning the principle of chemotaxis based drug/epitop delivery. Results achieved were presented in International journals and conferences. Our findings could be considered as useful contribution to the development of macromolecule based targeting for drug research and/or immundiagnostics

Community dynamics and function of algae and bacteria during winter in central European great lakes

Abundant phytoplankton and bacteria were identified by microscopy and high-throughput 16S rRNA tag Illumina sequencing of samples from water- and ice phases collected during winter at two central European Great Lakes, Balaton and Fertő (Neusiedlersee). Bacterial reads at all sites were dominated (\u3e85%) by Bacteroidetes and Proteobacteria. Amongst phototrophs, microscopy and 16S sequencing revealed that both phytoplankton and cyanobacteria were represented, with a median of 1500 cyanobacterial sequence reads amongst 13 samples analyzed. The sequence analysis compared replicate Balaton and Fertő ice and water samples with an outgroup from three Hungarian soda lakes. In particular, both water and ice from Fertő contained high contributions from cyanobacteria. Two percent of total reads identified to the level of family in water at Fertő were dominated by a single operational taxonomic unit (OTU) of a cyanobacterium within the Rivulariaceae, which was largely absent from ice. Conversely, ice samples from both lakes yielded an abundant OTU assigned to a Flavobacterium sp. known to be associated with freshwater ice. Principal Coordinates Analysis (PCoA) revealed that the ice communities from all sites were similar to one another, and that the water communities did not cluster together. Fluorescence emission spectra obtained at 77 K confirmed the presence of intact cyanobacteria in Fertő water and ice. Photosynthetic characterization of phototrophs resident in water and ice analyzed by assay of acid-stable photosynthetic H14CO3– incorporation showed that communities from both phases were photosynthetically active, thus adding to growing recognition of ice-covered lakes as viable habitat for phototrophs

Inhibiting α-Synuclein Oligomerization by Stable Cell-Penetrating β-Synuclein Fragments Recovers Phenotype of Parkinson's Disease Model Flies

The intracellular oligomerization of α-synuclein is associated with Parkinson's disease and appears to be an important target for disease-modifying treatment. Yet, to date, there is no specific inhibitor for this aggregation process. Using unbiased systematic peptide array analysis, we indentified molecular interaction domains within the β-synuclein polypeptide that specifically binds α-synuclein. Adding such peptide fragments to α-synuclein significantly reduced both amyloid fibrils and soluble oligomer formation in vitro. A retro-inverso analogue of the best peptide inhibitor was designed to develop the identified molecular recognition module into a drug candidate. While this peptide shows indistinguishable activity as compared to the native peptide, it is stable in mouse serum and penetrates α-synuclein over-expressing cells. The interaction interface between the D-amino acid peptide and α-synuclein was mapped by Nuclear Magnetic Resonance spectroscopy. Finally, administering the retro-inverso peptide to a Drosophila model expressing mutant A53T α-synuclein in the nervous system, resulted in a significant recovery of the behavioral abnormalities of the treated flies and in a significant reduction in α-synuclein accumulation in the brains of the flies. The engineered retro-inverso peptide can serve as a lead for developing a novel class of therapeutic agents to treat Parkinson's disease

Bacillus anthracis Peptidoglycan Stimulates an Inflammatory Response in Monocytes through the p38 Mitogen-Activated Protein Kinase Pathway

We hypothesized that the peptidoglycan component of B. anthracis may play a critical role in morbidity and mortality associated with inhalation anthrax. To explore this issue, we purified the peptidoglycan component of the bacterial cell wall and studied the response of human peripheral blood cells. The purified B. anthracis peptidoglycan was free of non-covalently bound protein but contained a complex set of amino acids probably arising from the stem peptide. The peptidoglycan contained a polysaccharide that was removed by mild acid treatment, and the biological activity remained with the peptidoglycan and not the polysaccharide. The biological activity of the peptidoglycan was sensitive to lysozyme but not other hydrolytic enzymes, showing that the activity resides in the peptidoglycan component and not bacterial DNA, RNA or protein. B. anthracis peptidoglycan stimulated monocytes to produce primarily TNFα; neutrophils and lymphocytes did not respond. Peptidoglycan stimulated monocyte p38 mitogen-activated protein kinase and p38 activity was required for TNFα production by the cells. We conclude that peptidoglycan in B. anthracis is biologically active, that it stimulates a proinflammatory response in monocytes, and uses the p38 kinase signal transduction pathway to do so. Given the high bacterial burden in pulmonary anthrax, these findings suggest that the inflammatory events associated with peptidoglycan may play an important role in anthrax pathogenesis