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Structure-function relationships and use of RTX proteins of Gram-negative bacteria
Sadílková, Lenka
RTX (Repeat in ToXin) superfamily consists of many proteins divided into several groups according to their different functions and characteristics: toxins, metalloproteases, lipases, proteins of the S-layer, bacteriocins and proteins with unknown function. However, all of them can be characterized by the following features: i) they contain tandemly repeated (6-50) nonapeptide glycine-rich calcium-binding consensus sequences GGXGXDX[L/I/V/W/Y/F]X (where X is any amino acid residue) in the C-terminal part of the protein. The presence of these repeats is a sine qua non condition for RTX protein family membership; ii) secretion from the cell occurs without a periplasmic intermediate by a mechanism which involves recognition of a signal sequence at the C-terminus of the protein by membrane-associated proteins that export the toxin across a channel spanning the entire bacterial envelope directly to the outside of the cell (Type I Secretion System); iii) the genes for protein synthesis, activation and secretion are mostly grouped together on the chromosome and form rtx operons. RTX toxins are the largest protein group of the RTX family. To this group belong mostly the proteins with molecular weight ranging from 100 to 200 kDa, with posttranslational fatty acid acylation mediated by a specific activating...
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Immune response to experimental active immunotherapy DCVac/OvCa in patients with ovarian carcinoma in phase II clinical trials.
Ksandrová, Marie ; Sadílková, Lenka (advisor) ; Krulová, Magdaléna (referee)
The immunotherapeutic drug DCVAC/OvCa is being tested in the treatment of ovarian cancer patients within the SOV02 clinical trial (Eudra CT number: 2013-001323-38). Ovarian cancer belongs to gynaecological malignancies with the highest mortality rate. Around 60% of patients are diagnosed at advanced stages. Despite the initial successful treatment, relapses occur in most cases, and the disease often becomes resistant to chemotherapy. Effective therapy for relapsed or metastatic patients is still missing. The solution could be immunotherapeutic treatment. DCVAC is an active cellular immunotherapy based on autologous dendritic cells. The aim of this diploma thesis was monitoring of immune parameters in samples from clinical trial SOV02 patients during the time period defined in the study protocol. We have monitored the presence of antigen specific T lymphocytes, tumor specific antibodies, immunosuppressive populations of regulatory T cells and MDSC cells, and also the expression of inhibitory molecules on the surface of T lymphocytes. We observed higher levels of Her-2, Muc-1 and MAGE-A1 antibodies in the DCVAC/OvCa treated group of patients versus the control group. Significant differences in the other monitored parameters were not observed. However, a large amount of data have been obtained that...
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mTOR mediated phosphorylation of Akt at Ser473 regulates cancer cell survival after severe hypertermia in PTEN-coordinated manner
Valentová, Iva ; Sadílková, Lenka (advisor) ; Černý, Jan (referee)
Hyperthermia (HT), a term used in general for temperatures higher than 42řC, induces cell stress response in dependence on its intensity, heating duration and target cell type (this is called a thermal dose). In vitro, HT causes changes in Ca2+ homeostasis as a consequence of endoplasmic reticulum stress and permeabilisation of the outer mitochondrial membrane. The release of cytochrom c further leads to activation of caspases that can result in cell death. In parallel, the presence of denatured proteins in the cell cytosol leads to the development of the so called unfolded protein response (UPR). UPR is characterized by increased expression and activation of molecular chaperones, increase in the intensity of proteosomal degradation and enhancement in autophagy. This process is accompanied by the attenuation of translation machinery, iniciation of DNA repair and activation of cytoprotective mechanisms leading to cell survival. This highly complex stress response mechanism is regulated mainly by the signalling pathways in the PI3K/Akt/mTOR axis. Cell survival is in the end fully dependent on the amount of energetic substrates, denatured proteins accumulation and on the level of irreversibly demaged DNA. If the termal dose is too high, the cell will ultimatively die. Hyperthermia is also one of the...
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Structure-function relationships and use of RTX proteins of Gram-negative bacteria
Sadílková, Lenka
RTX (Repeat in ToXin) superfamily consists of many proteins divided into several groups according to their different functions and characteristics: toxins, metalloproteases, lipases, proteins of the S-layer, bacteriocins and proteins with unknown function. However, all of them can be characterized by the following features: i) they contain tandemly repeated (6-50) nonapeptide glycine-rich calcium-binding consensus sequences GGXGXDX[L/I/V/W/Y/F]X (where X is any amino acid residue) in the C-terminal part of the protein. The presence of these repeats is a sine qua non condition for RTX protein family membership; ii) secretion from the cell occurs without a periplasmic intermediate by a mechanism which involves recognition of a signal sequence at the C-terminus of the protein by membrane-associated proteins that export the toxin across a channel spanning the entire bacterial envelope directly to the outside of the cell (Type I Secretion System); iii) the genes for protein synthesis, activation and secretion are mostly grouped together on the chromosome and form rtx operons. RTX toxins are the largest protein group of the RTX family. To this group belong mostly the proteins with molecular weight ranging from 100 to 200 kDa, with posttranslational fatty acid acylation mediated by a specific activating...
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Structure-function relationships and use of RTX proteins of Gram-negative bacteria
Sadílková, Lenka ; Šebo, Peter (advisor) ; Stulík, Jiří (referee) ; Weiser, Jaroslav (referee)
RTX (Repeat in ToXin) superfamily consists of many proteins divided into several groups according to their different functions and characteristics: toxins, metalloproteases, lipases, proteins of the S-layer, bacteriocins and proteins with unknown function. However, all of them can be characterized by the following features: i) they contain tandemly repeated (6-50) nonapeptide glycine-rich calcium-binding consensus sequences GGXGXDX[L/I/V/W/Y/F]X (where X is any amino acid residue) in the C-terminal part of the protein. The presence of these repeats is a sine qua non condition for RTX protein family membership; ii) secretion from the cell occurs without a periplasmic intermediate by a mechanism which involves recognition of a signal sequence at the C-terminus of the protein by membrane-associated proteins that export the toxin across a channel spanning the entire bacterial envelope directly to the outside of the cell (Type I Secretion System); iii) the genes for protein synthesis, activation and secretion are mostly grouped together on the chromosome and form rtx operons. RTX toxins are the largest protein group of the RTX family. To this group belong mostly the proteins with molecular weight ranging from 100 to 200 kDa, with posttranslational fatty acid acylation mediated by a specific activating...
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