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Microsoft Windows Registry Analysis
Hula, Miroslav ; Drozd, Michal (referee) ; Chmelař, Petr (advisor)
Understanding and working with Microsoft Windows registry is an important ability from the perspective of security. This ability is used by malicious software as well as by software, which repaires the damage caused by activity of malicious software. However, applications accessing and working with the registry are platform dependent, which may not always be convenient and it can lead to other problems if the platform is not secure. Therefore, the aim of this work is to create a platform independent application for accessing and working with registry, which makes possible to analyse the effect of malware on registry.
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Cytokine networks and their impact on the immune profile of acute myeloid leukemia (AML) patients
Ptáček, Antonín ; Musil, Jan (advisor) ; Fišer, Karel (referee)
Acute myeloid leukemia (AML) is a malignant hematological disorder characterized by aberrant expansion of blasts in the bone marrow and peripheral blood. The immune system protects the body from leukemia by eliminating transformed cells. However, in AML, the abilities of immune cells are affected both by direct contact between leukemic cells and effector cells, as well as by cytokines, metabolites and other soluble proteins that, together with the cells, form the specific AML microenvironment. The effects of cytokines and other soluble molecules in the AML microenvironment are not sufficiently described yet. This thesis aimed to optimize and implement a multiparametric flow cytometry panel for the measurement of cell populations and to implement multiparametric assays for the analysis of cytokine levels, chemokines and other soluble proteins in plasma. The following goal was to use these methods to characterize the frequency and functional phenotype of cell populations and the levels of the soluble proteins and to describe their influence on disease severity and overall survival of the patients. We also tried to find novel biomarkers of the immune escape of leukemic cells. In patients, we observed a suppressive microenvironment with aberrant levels of soluble receptors and other proteins. This...
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The role of γc cytokines in the immune system and cancer immunotherapy
Ptáček, Bohumil ; Kovář, Marek (advisor) ; Adkins, Irena (referee)
Cytokines are proteins produced mostly by cells of hematopoietic origin and transduce signals via engaging cell surface receptors on either the cytokine-producing cells (autocrine signaling) or other target cells (paracrine signaling). Common cytokine receptor subunit (γc) cytokines are small glycoproteins belonging to type I cytokines with pleiotropic activities in both the innate and adaptive immune systems. All γc cytokines share a γc receptor subunit in their complete receptors. The first part of this thesis aims to summarize information about the biology of γc cytokines, their receptors, and their role in the immune system and its functions. The second part discusses the use of γc cytokines in cancer immunotherapy, presenting examples of particular γc cytokine therapies, and describes the approaches to improve the pharmacological features of γc cytokines or efficiently combine them with other immunotherapies and anticancer treatments. Keywords: γc cytokine, cytokine receptor, T cell, NK cell, cancer immunotherapy
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Preparation of rat NK cell receptors using HEK293T expression system.
Celadová, Petra ; Bezouška, Karel (advisor) ; Půta, František (referee)
Natural killer cells play a significant role in the immune response against tumor and infected cells. NK cells express a wide variety of surface receptors, including NKRP1, a C-type lectin-like family of both activating and inhibitory receptors. Recently, ligands have been found for some of these previously orphan molecules, some of them lying within the same family. This is also the case of rat Clr-b as a cognitive ligand for rat NKRP1B. It has been shown that in rat, this inhibitory NKRP1B-Clr-b mutual receptor system is subverted by rat cytomegalovirus protein RCTL, a viral version of Clr-b, which serves as a decoy ligand for NK cells. The aim of my diploma thesis was cloning and production of the above mentioned C-type lectin-like proteins based on transient transfection of HEK293T cell line in a suspension culture. This expression system allows us not only to obtain proteins of our interest with a satisfactory yield but also in their native conformation, removing the need for time consuming and often fruitless refolding procedures required in case of using the E. coli expression system. Success was achieved in case of Clr-b and NKRP1B receptors from both WAG and SD strains. Proteins were purified using IMAC followed by gel filtration, identified by mass spectrometry and characterized by disulfide...
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Studies on interactions between natural killer cell lectin receptors and their protein ligands.
Hernychová, Lucie ; Novák, Petr (advisor) ; Drbal, Karel (referee)
NK cells are innate lymphocytes which constitute the first line of organism's defence against infections through their receptor system. These cells represent an important part of antiviral and antitumor immunity, they also play a role in transplant immunity, autoimmunity and reproduction. This diploma thesis inquires into the structure of the transmembrane receptor NKR-P1B of mouse NK cells and the interaction with its ligand Clr-b. The aim was to prepare the expression vector coding the ligand-binding and whole extracellular region of the receptor NKR-P1B and to optimize its production and refolding in vitro. Purified protein samples were analyzed by size-exclusion chromatography, electrophoresis and mass spectrometry. Interaction between NKR-P1B and Clr-b proteins was tested using biophysical (size-exclusion chromatography and surface plasmon resonance) and biological methods (labelling of cellular sample with NKR-P1B proteins marked with fluorescent dye). In vitro binding experiments have not confirmed mutual interaction between NKR-P1B and Clr-b despite the prepared proteins binding to the bone marrow cells.
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Study of structure and interaction of human lymphocyte receptors
Bláha, Jan ; Vaněk, Ondřej (advisor) ; Šulc, Miroslav (referee) ; Obšil, Tomáš (referee)
Natural killer (NK) cells are an essential part of immune system, providing self-surveillance of virally infected, stress transformed or cancerous cells. NKR-P1 receptors and their ligands from clec2 gene family represent an alternate missing-self recognition system of NK cells based on interaction of highly related C-type lectin-like receptors. Human NKR-P1 has been described more than twenty years ago but still remains the sole human orthologue of this receptor family, particularly numerous in rodents. On binding to its cognate ligand LLT1, NKR-P1 can relay inhibitory or co-stimulatory signals. Although being interesting targets for their potential role in tumor immune evasion and autoimmunity, nature of their interaction is still unclear. To elucidate the architecture of their interaction, we developed a generally applicable method for recombinant expression of human NKR-P1 and LLT1 and their homologues based on transfection of HEK293S GnTI- cells. Further, we described a stabilizing mutation His176Cys, that enables for expression of highly stable and soluble LLT1. Finally, we have crystallized LLT1 and human NKR-P1 in different glycosylation states both as individuals and in complex. While both structures of LLT1 and NKR-P1 follow the classical C-type lectin-like superfamily fold, contrary to...
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Structural biology of complex of rat NK cell receptors NKR-P1B and Clrb
Dvorská, Anna ; Vaněk, Ondřej (advisor) ; Ingr, Marek (referee)
The Natural Killer (NK) cells have an important role in the nonspecific immunity of the or- ganism. They have the ability to identify and to kill tumor cells and cells infected by a virus without preceding sensitization by antigen. Their function is directed by the amount of sti- mulation and inhibition receptors interacting with ligands on the tumor or infected cell. This thesis focuses on the preparation and the study of the complex of rat NK cellular inhi- bition receptor NKR-P1B ("natural killer cell receptor - protein 1B") and its ligand Clrb ("C-type lectin-related ligand b"). The Clrb initiates the inhibition of NKR-P1B, meaning that if the cell express Clrb, it won't be destroyed. If the cell gets infected by the rat cytome- galovirus, it loses Clrb from its surface and its destruction is therefore no longer prevented. Cells infected with this virus defend themselves from destruction by expression of the viral gene of C-type lectin RCTL, which is a homolog of Clrb. Transient transfection of human embryonic kidney 293 cell line with simple glycosylation (HEK293S GnTI− ) was used for the recombinant preparation of the soluble form of these two receptors of the rat NK cells. The native forms of the receptors - disulfidic homo- dimers - were prepared as the fusion construct with IgG Fc (using...
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Preparation of expression vectors for receptor NKp30 and its ligands B7-H6 and BAG-6
Pažický, Samuel ; Vaněk, Ondřej (advisor) ; Milichovský, Jan (referee)
NK cells, the cells of non-adaptive imune system, are able to recognise viraly infected or oncogenous cells by many inhibiting and activating receptors that are expressed on their surface and eliminate them consequently. For NKp30, activating receptor of NK cells included in NCR (Natural Killer Cell Receptors) family, lately there were identified several ligands, including membrane protein B7-H6 expressed on oncogenous cells surface and BAG- 6, cell core protein with wide spectrum of functions. Aim of this thesis was preparation of expression vectors coding for receptor NKp30 and his ligands B7-H6 and BAG-6, enabling expression of these proteins in HEK293 cell line. Keywords: NK cell, plasmid, receptor, NKp30, B7-H6, BAG-6
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Mutagenesis and expression of protein NKp80, the activation receptor of human lymphocytes
Pazderová, Kristýna ; Vaněk, Ondřej (advisor) ; Ječmen, Tomáš (referee)
The subject of this study is a receptor NKp80, also known as killer cell lectin-like subfamily F, member 1 (KLRF1). It is an activating receptor which forms homodimers on the surface of natural killer (NK) cells. Receptor NKp80 binds to a ligand, AICL, which is naturally expressed on all myeloid cells. Upon a substantial increase in AICL expression, for example in cancer cell, the cell then becomes a target for an NK cells expressing the receptor NKp80. Ultimately, the complex NKp80:AICL is therefore a potential target for the immunotherapeutic treatment of myeloid leukaemia. The aim of the study was to the produce and purify a series of mutants of an extracellular domain of NKp80 by replacing cysteins by serines in a segment of extracellular domain called the stalk region. Here, by introducing the mutations, we studied their effect on homodimer formation. The proteins were prepared in HEK293S GnTI- cells using stable transfection. Altogether, we produced seven mutants with all possible combinations of mutations of the three cysteins in the stalk region. We then analysed the proteins using size exclusion chromatography and differential scanning fluorimetry. Lastly, we deglycosylated the proteins to verify that NKp80 is present in several glycoforms. Our results show that none of the variants of...
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