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Activation of the initiation caspases and regulation of their activity
Votavová, Barbora ; Anděra, Ladislav (advisor) ; Černý, Jan (referee)
Caspases are the key proteins participating in both activation and execution of apoptosis. Extrinsic or intrinsic apoptotic signaling leads to sequential activation of the initiation and execution caspases. Activation of initiator caspases is mediated by their processing in multiprotein complexes and activated initiator caspases then specifically cleave and thus activate the effector caspases. These then cleave a number of structural and functional proteins, which consequently leads to cellular selfdestruction and its breakdown to apoptotic bodies. Considering the fundamental significance of the initiation of apoptosis, the activation as well as the activity of initiator (but also effector) caspases is strictly regulated at several levels. Primary the intensity and character of the recieved signal is crucial for the effective formation of the caspase activation complex. Then the concentration of intracellular ionts, nucleotides and various proteins (proteins from the Bcl-2 family, inhibitors of apoptosis (IAPs), heat shock proteins,…) can also highly influence individual steps of caspase activation. Caspases themself can be posttranslationally modified (phosphorylated, ubiquitylated,…) and their activity can be either suppressed or also enhanced. All these processes form complex regulatory network serving...
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Emerging role of Toll-like receptors in central tolerance
Súkeníková, Lenka ; Filipp, Dominik (advisor) ; Černý, Jan (referee)
Medullary thymic epithelial cells (mTECs) provide a specific thymic microenvironment for the processes associated with T cell development. Their irreplaceable function is the expression of specific set of antigens which are expressed only in peripheral tissues, called tissue restricted antigens (TRAs). Such expression, often referred to as promiscuous, was originally described with the discovery of transcriptional regulator Aire. Aire, which has a potential to interact with many other transcription factors, also binds to DNA, and thus can alter the general pattern of cellular gene expression. T cells exhibiting a strong affinity to TRAs expressed on mTECs are removed from the thymus by negative selection or their development is deviated to regulatory T cell (Treg) lineage. Studies on mice and humans confirmed the critical role of Aire protein in the establishment of the central tolerance. Inactivating mutations in Aire gene cause deficiency in TRA expression, failure to remove and the escape of self-specific T cells from the thymus to periphery, and in turn, autoimmunity. Experimental evidence points to the key role of NF-κB signaling pathway in mTECs development. The very same pathway is regulated also by Toll-like receptors (TLRs), which recognize evolutionary conserved structures derived from...
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Cell-mediated peripheral tolerance in lymph nodes
Brabec, Tomáš ; Filipp, Dominik (advisor) ; Černý, Jan (referee)
Tolerance of immune system to body-self constituents is a crucial issue for immunologists to solve. While the mechanisms of central tolerance are now described to well extent, antigen-specific tolerance mechanisms on immunological periphery are just beginning to be revealed, characterized and appreciated. Recently, novel models of peripheral tolerance emerged. Particularly, a model based mostly on lymph node stromal cells could be of profound importance, since it provides answers to some fundamental questions in tolerance immunology. So far, no review paper highlighting these newly discovered roles of lymph node stromal cells was published. Therefore, in this study we summarize data covering this topic, published up-to-date. Further, this text provides a basic overview of lymph node functional anatomy. To better illustrate the topic, we also show some experimental evidence demonstrating lymph node architecture and the localization of extrathymic Aire-expressing cells, one of the lymph node-resident populations, recently implicated in peripheral tolerance maintenance. Powered by TCPDF (www.tcpdf.org)
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Appearing and Salvation. Subjectivity in The Material Phenomenology of Michel Henry
Černý, Jan ; Novotný, Karel (advisor) ; Švec, Ondřej (referee) ; Karul, Róbert (referee)
The doctoral thesis examines the possibilities of phenomenological philosophy to engage in the question of salvation in a Christian sense with reference to Michel Henry's material phenomenology. Henry's last three books signified a turn towards Christianity within his work and related the tension of two basic modes of appearing, assumed by his phenomenology, to the question of the life and death of a human. Material phenomenology strongly exposed the subjective pole of appearing and made subjectivity the stage for the story of human salvation. The thesis examines both the general concept of subjectivity in material phenomenology and the particular concept of a divine and human subject in the last three books of Michel Henry. The thesis follows the way Michel Henry creates the phenomenology of the inner- divine life; it examines the movement of a human subject from the inside of the divine life to the transcendence of the world, and then its return through the "second birth" to the divine life being displayed within itself; it enquires in what sense the divine and human subject are incarnated subjects; it demonstrates how the human subject is becoming a subject understanding the word of a divine life which speaks both within itself and in the Scripture. The thesis pays attention to the relation of a...
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Aire-expressing cells in immune peripheral tissues
Vobořil, Matouš ; Filipp, Dominik (advisor) ; Černý, Jan (referee)
5 Abstract Tolerance to "self" is the fundamental property of the immune system and its breakdown can lead to autoimmune diseases. In order to eliminate self-reactive T- cells during their development in thymus (central tolerance), Aire promotes the expression of peripheral self-antigens in medullary thymic epithelial cells (mTECs). Recently, Aire was suggested to fulfil a similar function in rare lymph node and spleen cells (peripheral tolerance). However, the detection, characterization and function of these extrathymic Aire-expressing cells is still obscure. The main objective of presented thesis was to investigate if Aire positive cells are also present in other lymphoid as well as non-lymphoid tissues. Using two independent mouse transgenic models we identified the Aire-reporter expressing cells in several lymphoid tissues such as Peyer's patches, spleen and bone marrow as well as in one non-lymphoid organ, the lungs. We show here that based on the expression of B220, EpCAM and CD11c markers these heterogenic cells consist of at least five phenotypically distinct subpopulations, and with the exception of those from lungs, all of them are strictly of hematopoietic origin. This study also demonstrates that Aire on protein level is predominantly expressed by one of these subpopulations with CD45+ MHCII+...
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Transmembrane adaptor proteins and their roles in immunoreceptor signaling
Borna, Šimon ; Hořejší, Václav (advisor) ; Černý, Jan (referee)
Transmembrane adaptor proteins are group of proteins, which lack intrinsic enzymatic activity, but they share similar structure. They play essential role in signal transduction, because they are able to recruit cytoplasmic proteins to proximity of plasma membrane and thus trigger signal pathways. In this review I mainly focused on these, which were not reviewed for a long time, or were recently discovered and I am trying to summarise current knowledge about roles of these proteins in leukocyte signalling. Key words: transmembrane adaptor proteins, receptor signaling, immunoreceptors
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Expression of immunogenic cell death markers on lung cancer cells
Kobosilová, Linda ; Špíšek, Radek (advisor) ; Černý, Jan (referee)
Immunogenic cell death (ICD) is characterized by presence of specific molecules including surface exposed calreticulin (CRT) and the heat shock proteins HSP70 and HSP90. Release of ATP and high- mobility group box protein 1 (HMGB1) belongs to other typical characteristics. For induction of ICD in lung cancer cells high-hydrostatic pressure (HHP) was used. Treatment by HHP induces expression of immunogenic markers CRT, HSP70 and HSP90 on the cell surface. HHP also induces secretion of ATP to the extracellular milieu. Dendritic cells (DC) pulsed with HHP-treated tumor cells showed fenotypic maturation characterized by upregulation of maturation molecule CD83, costimulation molecules CD80 and CD86, chemokine receptor CCR7 and MHC class II molecule HLA-DR. Pulsed DCs have also higher rate of phagocytosis of HHP-treated tumor cells and they induce lower numbers of regulatory T cells compared to immature DCs. Moreover, activation of caspases (-8, -9, -3) and other proteins (phosphorylation of eIF2α) which are crucial in ER-stress mediated apoptotic pathway, was observed after HHP treatment. Using wide range of methods it was confirmed that HHP treatment is able to induce ICD in lung cancer cell lines, fenotypic and functional characteristics were described and the decreased induction of regulatory T-lymphocytes...
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Lectin receptor-ligand interaction important in experimental tumor therapy
Grobárová, Valéria ; Černý, Jan (advisor) ; Filipp, Dominik (referee) ; Krulová, Magdaléna (referee)
Lectin-saccharide interactions are involved in many biological processes essential for the survival and proper function of multicellular organisms. C-type lectin-like receptors, predominantly expressed by cells of the innate immune system, recognize saccharide structures on microbes and also aberrant glycosylation pattern of cancer cells. The NKR-P1 receptor family was among the first natural killer (NK) receptor families that were identified, however ligands for some of members remain still elusive. Recently, publications describing N-acetylglucosamine-terminated oligosaccharide structures as possible ligands for NKR-P1 receptor have been subjects for correction/retractions after investigation of the Ethical Committee of the Institute of Microbiology, ASCR, v. v. i. and Charles University in Prague. Re-evaluation of glycodendrimer effect, particularly effect of N-acetyl-D-glucosamine octabranched dendrimer on polyamidoamine scaffold (GN8P), revealed mostly indirect role of NK cells on modulation of immune responses. Properly folded soluble recombinant rat NKR-P1A and mouse NKR-P1C lack binding activity to neoglycoproteins modified with GlcNAc-terminated structures. Moreover, new possible target cell populations (NKT cells and macrophages) for saccharide binding were identified.
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The community and protection of the environment from the legal point of view
Černý, Jan ; Žákovská, Karolina (advisor) ; Snopková, Tereza (referee)
The aim of this thesis is to analyse position and possibilities of a municipality in the Czech Republic in the field of environmental protection. The thesis is divided into six basic parts. The Introduction briefly illustrates the importance of municipalities and explains the system of this thesis. Chapter One deals with the environment, especially with its protection under the Czech constitutional law. Municipalities and their bodies are characterised in Chapter Two. The next chapter describes the town and country planning and examples of bylaws issued by a municipality within its separate power in order to protect the environment. Chapter Four introduces the legal instruments which can be used by a municipality in environmental protection within delegated power. In the Conclusion, the author draws attention on several problems connected with participation of municipalities in environmental protection, nevertheless he highlights that municipalities play an unquestionable role in this field.
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TAL Effectors: Tools for DNA Targeting
Jankele, Radek ; Svoboda, Petr (advisor) ; Černý, Jan (referee)
Two decades of research on interactions between Xanthomonas phytopathogenic bacteria and their hosts resulted in discovery of a novel Transcription Activator-Like Effector (TALE) protein family, which confers bacterial virulence in plants. TALEs bind selectively to plant promoters and activate expression of cognate genes enabling bacterial reproduction and dissemination. TALEs mediate recognition of specific promoter boxes in a simple and predictable manner. The TALE central repeat domain contains tandem repeats, which specifically contact single consecutive nucleotides in the target sequence via polymorphic amino acid residues. Repeats stack together in an unique right-handed superhelical assembly, which wraps around the DNA duplex. Validated TALE-DNA binding code shows, that two polymorphic amino acids NI, HD, NH, NG and NN in each repeat mediate recognition of A, C, G, T and A/G, respectively. The order of repeats determines recognized sequence in DNA sense strand. Custom TALE DNA-binding domains with desired specificities can be created within one week at low cost. Such designed domains fused to nuclease or activation domains are useful in research, biotechnology and gene-therapy for targeted gene editing and gene regulation. Notably, gene editing with custom-designed TALE nucleases (TALENs) allows for...
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