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Activation and regulation of cell death in senescent cancer cells.
Holíček, Peter ; Anděra, Ladislav (advisor) ; Drbal, Karel (referee)
Cellular senescence is a distinct cell state, characteristic by cessation of cell proliferation and it is accompanied by specific morphological and biochemical alterations. Increasing and persisting incidence of senescence cells has been shown to have detrimental effect on an organism largely contributing to its ageing. Senescent cells also positively support tumour growth and can even stimulate carcinogenic transformation of surrounding cells. Moreover, senescence can be induced even in tumour cells spontaneously or by chemotherapy. Regardless of an initial stimuli and type of cells, there are two main senescence inducing pathways p16/pRb and p53/p21. Both senescent cells as well as senescent cancer cells seems to have modified apoptotic signalling at the level of mitochondria and Bcl-2 family proteins. In this study, we aimed to analyse effect of senescent state as well as pre-senescent (growth arrested state) induced by p16/pRb and p53/p21 signalling pathways on the response of H28 mesothelioma cancer cells-derived clonal cultures to various cell death-inducing stimuli. By inducible expression of p16 and p21 proteins in doxycycline-dependent manner, we forced cells to acquire senescent-like phenotype, which we detailly characterised. Our results showed that senescent-like phenotype, manifests...
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Immunogenicity of induced pluripotent stem cells (iPSC)
Tejklová, Tereza ; Drbal, Karel (advisor) ; Hájková, Michaela (referee)
Ectopic expression of several transcription factors into the somatic cells allows us to artificially dedifferentiate them into induced pluripotent stem cells (iPSC), which show great promise in regenerative medicine and personalized disease modelling, as well as diagnostic tools. Unique attribute of iPSC is the possibility of creating autologous cells for each patient, which could be used for transplantation without fear of immune rejection. However, cells differentiated from iPSC generally display decreased expression of MHC I glycoproteins, which leads to the activation of NK cells of innate immunity. T cells, the part of adaptive immunity, are activated after recognition of antigen peptide or foreign MHC I glycoproteins only in co-operation with costimulatory molecules, which are not usually expressed on iPSC. During dedifferentiation, cells keep the epigenetic profile of the source cell, which can result in the abnormal expression of genes within derived cell lines. Overall immunogenicity depends on the method of iPSC preparation, with respect to genomic stability. Another important factor is the immune environment of transplantation site as well as the tissue damage caused during transplantation. This results in the presentation of danger signals (DAMPs), which are then recognized by pattern...
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Immunogenic cell death
Šímová, Michaela ; Drbal, Karel (advisor) ; Javorková, Eliška (referee)
According to the danger model, the immune system is activated by endogenous molecules known as danger-associated molecular patterns (DAMP) that are externalized from the interior of a dying cell to the cell surface or released into the extracellular space. Due to the loss of plasma membrane integrity a necrotic cell death as well as several types of proinflammatory programmed cell death are considered to be immunogenic, whereas apoptosis, on contrary, has been initially defined as a tolerogenic type of cell death. However, under certain circumstances, the immune response can be initiated by an apoptotic cell after exnternalization of DAMP molecules by newly described secretory pathways. This phenomenon was observed on tumor cells as a result of some widely used therapeutic modalities and is known as immunogenic cell death (ICD). Nomenclature of selected types of cell death is part of this thesis. The aim of this bachelor thesis is to provide an evidence of the experimental support for ICD theory during in vivo initiation of the immune response. I will evaluate the correlation between ICD and the induced exposure of DAMP molecules on the surface of tumor cells or their secretion to the extracellular space.
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Microvesicle and exosome detection in immune-related diseases
Šťastná, Evelína ; Drbal, Karel (advisor) ; Fabišik, Matej (referee)
Exosomes (ES) and microvesicles (MV), collectively called extracellular vesicles (EV), are submicroscopic vesicles encapsulated by a phospholipid bilayer. Smaller ES (40 - 100 nm) originate in endosomal compartment, while larger MV (50 - 1000 nm) shed from cell plasma membrane. EV are secreted by all types of cells. They consist of lipids and proteins, but their composition varies according to the cell they originate from. In addition, they differ in the cargo they transport (DNA, RNA and proteins). They occur in every bodily fluid in much higher amounts compared to the original cells themselves, what makes them an attractive and accessible biomarker of autoimmunity diseases, cardiovascular diseases or tumours. For detection of EV, sensitive flow cytometry (FCM) is used, which I am going to compare to alternative methodologies. Part of this work will be description of EV biogenesis and then I will focus on the role of EV in coagulation and inflammation related to autoimmune diseases, more specifically in rheumatoid arthritis (RA).
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Human lymphopoiesis and its examination via single-cell analysis
Novák, David ; Kalina, Tomáš (advisor) ; Drbal, Karel (referee)
Development of human B-lymphocytes is a convoluted process. A self-renewing stem cell progenitor in a primary lymphoid tissue commits to the lymphoid lineage. Subsequent B-lineage commitment entails somatic gene recombination processes which lead to the eventual expression of a surface antigen receptor. Functionality of the B-cell receptor, as well as successful testing for autoreactivity by the cell, are preconditions for the differenti- ation of a mature B-lymphocyte. Processes within this development are often investigated using single-cell analysis via flow cytometry, fluorescence-activated cell sorting and mass cytometry. Coupling these high-throughput methods with modern approaches to data analysis carries enormous potential in revealing rare cell populations and aberrant events in haematopoiesis. Keywords: B-lymphocyte, lymphopoiesis, flow cytometry, FACS, mass cytometry, clus- ter analysis, FlowSOM, PCA, t-SNE, Wanderlust.
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Exprese CD47 a jeho topologie na povrchu primárních buněk karcinomu močového měchýře při interakci s makrofágy
Rajtmajerová, Marie ; Drbal, Karel (advisor) ; Brdička, Tomáš (referee)
CD47 is a so-called "don't eat me" signal, which protects cells from phagocytosis. Its high expresion on tumor cells brings new perspective to the tumor therapy. Monoclonal antibodies, which are these days undergoing clinical trials, prevent CD47 binding to the SIRPA inhibitory receptor on macrophages, and so they enhance their phagocytic functional capacity. In this way they enable phagocytic removal of tumor cells. Overall expression, structural conformation and stoichiometry of CD47 on a particular cell predestine whether it will be phagocytised. The aim of the thesis is to develop and test methods to characterise expression parameters of CD47 via flow cytometry (FCM), quantitative PCR (qPCR) and microscopy. To achieve this goal I performed competition tests of commercially available antibodies in order to characterise their binding epitopes on cell lines. After performing tSNE analysis of primary BCa patient samples I correlated CD47 expression with other cell surface markers. I focused on CD47 expression in various differentiation stages of the tumor. To better understand the relationship between CD47 expression and differentiation status of cells I performed qPCR analysis of particular transcription factors. Using cell lines I examined method for phagocytosis quantification, which will be...
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Immunopathology aspects and new treatment options for rheumatoid arthritis
Bartoňová, Michaela ; Šenolt, Ladislav (advisor) ; Drbal, Karel (referee)
Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease, which affects joints. It significantly affects the quality of life and is associated with increased mortality. Although its etiology is not fully known, it is believed that both genetic and environmental risk factors are involved in its outbreak. Knowledge of these risk factors helps us to determine the risk of RA outbreaks in vulnerable populations and provides us with knowledge about possible prevention. Pathogenesis of RA is caused by activated mesenchymal cells and cells of the innate and adaptive immune system, such as endothelial cells, synovial fibroblasts, monocytes, macrophages, dendritic cells, T and B lymphocytes. It is an incurable disease, but there are several medications, which improve disease activity or can even cause remission. Great success has been observed in biological treatment and inhibitors of Janus kinases. In some cases, the response to this relatively new therapy is not sufficient, and new drugs based on other mechanism should be developed. Examples include inhibition of granulocyte and macrophage colony stimulating factor, inhibition of interleukin 6 or interleukin 17 and bispecific antibodies. There is a growing importance of biosimilar drugs, which would make treatment, thanks to a lower price,...
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Somatic driver mutations during early differentiation of bladder carcinoma cell of origin
Brázdilová, Ludmila ; Drbal, Karel (advisor) ; Láníková, Lucie (referee)
A normal healthy cell traves through different routes to become a tumor cell, which according to the cell-of-origin theory initiates the whole tumor. Deregulation of cell processes by somatic mutations directs the cell into transformation. To this day, many mutations that cause a tumor phenotype, termed driver mutations, have been identified by genomic and targeted analyses. Not only for optimal therapy management but also for the prediction of disease progression the detection of driver mutations accumulating in the cell of origin of a specific tumor is very important. This thesis is focused on driver mutations of bladder carcinoma cell of origin, which is a tumor with a high mutation load. Bladder carcinomas compose a very heterogeneous group of tumors, having phenotype parallels in many other carcinomas, such as breast cancer. The driver mutations could be used as diagnostic and prognostic markers, but are not yet used in clinical practice. This thesis intends to summarize known findings about bladder carcinoma tumor initiation, based on understanding its cell of origin. Further characterisation of important driver mutations in bladder carcinoma and a comparison to other carcinomas is shown here, with respect to their molecular classification.
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Lyme borreliosis diagnostics using in vitro cellular immune response testing
Prokopová, Tereza ; Drbal, Karel (advisor) ; Melter, Oto (referee)
Lyme borreliosis is a multisystemic disease affecting skin, joints, heart and central nervous system. The disease is caused by spirochetes of Borrelia burgdorferi sensu lato complex. These bacteria are spread by ticks of Ixodes genus. In 2016 there were almost 4,000 newly infected individuals reported in the Czech Republic. Contemporary serological diagnostics of Lyme borreliosis is not sensitive nor specific enough and does not even correlate with the pathology of the disease in the early or late phases. For the correct diagnosis of the disease it is necessary to detect the pathogen and its genotype. For this reason we had aimed at two goals. Through the digital droplet PCR (ddPCR) method we detected Borrelia-specific DNA and its genotype. The detection limit of borrelial DNA was set on gDNA samples isolated from the tick. Detection threshold for the initial amount of 1 ng of tick gDNA is at the range of 10-17 g of specific borrelial DNA. Borrelia spp. coinfection was detected in 5 out of 12 tested samples. The most frequent type was B. garinii which was detected in 5 samples. On the basis of published sequences for virulent factors we have designed specific primers in conserved regions of the genes flanking their variable segments to be PCR amplified. Gene variability will be monitored through...
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Experimental verification of in silico predicted protein binder to FOXO4 transcription factor and transcriptome analysis of bladder cancer
Tauš, Petr ; Drbal, Karel (advisor) ; Převorovský, Martin (referee)
This diploma thesis includes an experimental and a bioinformatic part. The two parts are linked together through the subject of transcription factors of 'forkhead box O' (FOXO) family. FOXO transcription factors have a key role in many cellular processes including cell cycle regulation, apoptosis and metabolism. For a long time, they have been considered strictly as the tumor-suppressors yet a growing number of evidence is pointing out to their pro-tumorigenic role. In consequence FOXO transcription factors are studied intensively as potential therapeutic targets in cancer. In the past decade, in silico prediction of protein-protein interactions has become popular in basic research as well as in drug development. Nonetheless, the predicted structures are still far from fitting to the expected behavior of the respective biomolecules. In the experimental part of this thesis, I verified the interaction of four in silico predicted protein binders based on naturally occurring PDZ domain with FOXO4 using microscale thermophoresis. Non-invasive bladder tumors represent a heterogeneous disease where reliable prediction of tumor aggressiveness is still lacking despite an intensive research. In the bioinformatic part of this thesis, I described the cellular composition of the tumor microenvironment and demonstrated...
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