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Preparation of tumour ligand B7-H6 with coiled-coil tag and verifying of its binding to receptor NKp30
Krejčová, Kateřina ; Vaněk, Ondřej (advisor) ; Moserová, Michaela (referee)
Natural killer cells (NK cells) are part of innate antitumor immunity. These cells have the capacity to prevent viral infection or malignant transformation without prior antigen sensitization. Activation of NK cells consist of different recognition strategies. Mechanism of activation is based on down-regulated expression of MHC gp I molecules on the cell surface. NK cells possess both activation and inhibitory receptors that transmit activation or inhibitory signals which determine if NK cells are activated or not, and thus whether the target cell will be lysed or spared. NKp30 is a type I transmembrane receptor which recognize the stress-induced cell surface ligand B7-H6. Interaction of these two proteins leads to the initiation of immune response. The main aim of this thesis is the preparation of cell ligand B7-H6 with coiled-coil peptide tag in human embryonic kidney cell lines HEK293 GnTI- and HEK293T. Successful preparation of B7-H6 with coiled-coil tag on its C-terminus was verified by mass spectrometry. Its interaction with natural cytotoxicity receptor NKp30 was also proven by sedimentation analysis. Key words: NK cells, recombinant expression, B7-H6, HEK293, coiled-coil (This thesis is written in Czech)
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Preparation of reporter cell line for validation of recombinant protein biological activity
Kozojedová, Petra ; Vaněk, Ondřej (advisor) ; Moserová, Michaela (referee)
Natural killer cells belong to immune cells mediating non-specific immune response. On their surface, natural killer cells express many ligand-specific activation or inhibition receptors, among which belongs natural cytotoxicity activation receptor NKp30, which is able to trigger cytotoxic immune response upon interaction with its ligands. Natural cytotoxicity receptor NKp30 comprises of one immunoglobulin-like ligand-binding extracellular domain with short stalk domain, allowing the extracellular domain of NKp30 receptor to form oligomers, which leads to strengthening of ligand-receptor interaction. Furthermore, signalization leading to cell activation is affected by oligomerization of the extracellular domain of NKp30 receptor. This thesis focuses on preparation of constructs inspired by chimeric antigen receptor theory that carry extracellular domain of NKp30 receptor with stalk domain or only with ligand- binding domain and on validation of biological activity of prepared constructs after expression on the cell membrane. Two vectors for expression of the constructs inspired by chimeric antigen receptors carrying genes for extracellular domain of NKp30 receptor were prepared and to validate their biological activity, they were transfected into Jurkat cells. Key words: NK cells, NKp30, reporter...
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Preparation of recombinant forms of the extracellular part of mouse leukocyte receptors from NKR-P1 family.
Adámek, David
Mouse NK cell receptors belonging to NKR-P1 family plays role in activation, inhibition and cytokine secretion by these cells. Aim of this thesis is preparation of extracellular parts of C57BL/6 mouse strain activating receptors mNKR-P1A and mNKR-P1C. Production vectors with coding sequences of both proteins were prepared. Next, optimization of production in E. coli was done and appropriate in vitro refolding and purification protocol were developed. Purified proteins were characterized by mass spectrometry and labeled by a fluorescent dye. Primary screening for potential ligand was performed. Further work will involve structural characterization of the receptors and identification of their ligands. These data may help to clarify the function of NK cells.
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Effect of gluten-free diet on immune cell subsets in the NOD mouse model of type 1 diabetes
Tejklová, Tereza ; Funda, David (advisor) ; Krulová, Magdaléna (referee)
Type 1 diabetes (T1D) is an autoimmune disease leading to destruction of insulin-secreting pancreatic -cells. Environmental factors e.g. exposures to infections, dietary components play a substantial role in etiopathogenesis of T1D and are responsible for rapid increase of T1D incidence in past decades, preferentially in developed countries. Despite long record of T1D research no causative cure or efficient prevention exists. While gluten displays proinflammatory properties, gluten-free diet (GFD) has been documented by several studies as a strong diabetes- preventive environmental factor in spontaneous animal models of T1D, mostly in NOD mouse. The aim of this thesis is to better characterize effects of GFD on the immune system of NOD mouse. Using flow cytometry, we compared effects of GFD vs standard (STD) Altromin diets on NK cell subsets, Tregs, as well as other regulatory cell subsets and their cytokine profile in prediabetic SPF NOD females that were exposed to the diets since "in utero". A reference diabetes incidence in NOD females in our SPF facility kept on STD and GFD was recorded. Diabetes-preventive capacity of GFD were tested by using the NOD-SCID model of diabetes transfer, in which splenocytes from at-onset NOD females kept on GFD or STD were transferred to NOD-SCID recipients....
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Study of the interaction of receptor NKp46 with adhesin Epa1
Houserová, Jana ; Vaněk, Ondřej (advisor) ; Pavlíček, Jiří (referee)
One of the key components of the innate immune system are natural killer (NK) cells. The task of these cells is to induce apoptosis in target cells (e.g., cancer or virally infected cells). The target cells are identified by their interaction with surface receptors of the NK cells. On the surface of the NK cells, there are activating and inhibiting receptors. One of the activating receptors is the natural cytotoxicity receptor NKp46. Several ligands of this receptor have been identified, one of them being the epithelial adhesin Epa1 of yeast Candida glabrata. The invasive candidiasis caused by this yeast is a feared complication for patients with haematological diseases. The use of the NK cells in immunotherapy includes bispecific fusion proteins which can bind to the NK receptor with one part and to tumour antigen with the other part. This work focuses on recombinant preparation of the NKp46 protein. To facilitate a study of the effects of O-glycosylation on the binding of the ligands, a mutation of the glycosylation site NKp46 T225A was prepared. A stably transfected HEK293S GnTI- and HEK293T cells had been prepared and these proteins were then extracellularly secreted. The Epa1 protein had been produced in E. coli bacterial expression system and purified. The binding ability of the Epa1 protein...
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NK cells and KIR receptors: their importance in haematopoietic stem cell transplantations in leukemia
Ledvinková, Anna ; Vraná, Milena (advisor) ; Pačes, Jan (referee)
NK cells and KIR receptors: their importance in haematopoietic stem cell transplantations in leukemia Abstract This bachelor thesis discusses the importance of NK (natural-killer) cells in leukemias. It focuses on the structure and reactivity of NK cells, and especially on transmembrane KIR receptors (killer cell immunoglobulin-like receptors) of NK cells, that play an important role in the elimination of leukemic cells (graft-versus leukemia reaction, GvL) and thus in the overall prognosis of the disease. Activation and inhibitory receptors of KIR, by their cooperation, control the cytotoxic activity of NK cells. Thus, the typing of KIR receptor genes in hematopoietic stem cell donors can predict treatment success. KIR genes examination is mainly used in patients diagnosed with acute myeloid leukemia. Keywords: KIR receptor, NK cells, haematopoietic stem cell transplantation, HSCT, leukemia, donor, recipient
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Preparation of fusion ligands and evaluation of their binding to NK cell receptors
Nepokojová, Tereza ; Vaněk, Ondřej (advisor) ; Grantz Šašková, Klára (referee)
Natural killer cells (NK cells) are an important part of innate immunity. On their surface they express a complex group of receptors that use different signalling motifs to activate or inhibit NK cell cytotoxic activity. NK cells are capable to kill aberrant cells (namely, viral, infected, and tumour cells) by using special cytotoxic mechanisms to trigger apoptosis. The activating receptors recognize tumour or stress-induced ligands, e.g., NKG2D receptor recognizes the MICA ligand and NKp30 recognizes the B7-H6 ligand. Therefore for human immune system it is only natural that cancer cells are destroyed by NK cells. The current therapeutic goals in the treatment of cancer are primarily focused on strengthening the body's own natural ability to fight with cancer and one possible way is stimulation of NK cells to win this deadly fight. In addition to NK cells, antibodies are also widely used for the treatment of cancer, as well as other immune-related disorders. Most of them are monoclonal antibodies, but antibody fragments are getting attention and are being tested more and more in recent years. This work describes the preparation of three bifunctional fusion proteins: B7-H6-L-aHER2, MICA-L-aHER2, and aHER2-L-MICA, which contain immunoligands for the activating receptors of NK cell and VHH fragment...
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