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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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Interaction of Galectin-1 with human NK cell receptors
de Sousa Santos Abreu, Celeste ; Vaněk, Ondřej (advisor) ; Pavlíček, Jiří (referee)
Natural killer (NK) cells are a subpopulation of effector lymphocytes with cytotoxic activity and cytokine-producing functions considered as an integral part of the innate immune response. Functions of NK cells include tumour elimination, engagement and regulation of antiviral immune responses and regulation of immune cells by production and secretion of chemokines and cytokines. CD69 is a C-type lectin-like transmembrane receptor expressed in NK cells. CD69 is an activating receptor and acts also as a very early marker of lymphocyte activation. Putative protein ligands have been described for CD69 in the last years: Galectin-1, S1P1, S100A8/S100A9 and Myl9/12. Galectin-1 is a prototypical lectin characterized by the presence of a common lectin structural fold and a carbohydrate recognition domain involved in carbohydrate binding. Galectin-1 was identified as a binding partner for CD69 based on biological and functional studies, but structural details about the complex are still missing. This thesis describes the successful establishment of an expression protocol for a tag-less cysteine-less mutant of galectin-1 and the study of the interaction between galectin-1 and NK cell receptors. The interaction was studied using microscale thermophoresis and confirmed as dependent on the presence of a...
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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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The influence of S159A mutation on the oligomeric state of human NK cell receptor NKR-P1A
Hausleitner, Filip ; Vaněk, Ondřej (advisor) ; Kožíšek, Milan (referee)
Natural killer cells (NK cells) are lymphocytes that possess cytotoxic activity against tumour or virally infected cells independent of preceding antigen sensitisation. To kill such cells, they utilise their activating and inhibitory surface receptors that interact with target cell surface molecules. The immune response carried by NK cells depends on the balance of both activating and inhibitory signals. Human NK cell surface receptor NKR-P1A belongs to the structural family of C-type lectin-like receptors. This receptor interacts with its ligand LLT1, which belongs to the same protein family, with low affinity and high specificity. The NKR-P1A:LLT1 complex formed between NK cell and its target cell inhibits NK cell cytotoxicity, and hence is a part of the regulation of immune response. This thesis studied the effect of S159A mutation on the stoichiometric state of soluble human NKR-P1A ectodomain in solution. Therefore, a mutant form of NKR-P1A G90-S225 S159A ectodomain was successfully produced in stably transfected human embryonic kidney cells 293 (HEK293S GnTI" ). This construct was purified by affinity and size-exclusion chromatography, and analysed by SDS-PAGE and analytical ultracentrifugation. Our results show that the preclusion of N-linked glycosylation in the position 157 promotes the...
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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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The impact of obesity on the immune system with a focus on NK cells
Císařová, Radka ; Krulová, Magdaléna (advisor) ; Černý, Jan (referee)
Obesity is expanding rapidly even in developing countries and has negative effect on human health. The emerging low-grade chronic inflammation of visceral adipose tissue is generally accepted as the cause of this negative effect. The most important factor in the inflammation development is the induction of inflammatory phenotype of macrophages and their subsequent accumulation in visceral adipose tissue. The first impulse for these changes is ambiguous but can be associated with changes in phenotype and activation status of NK cells. NK cell mediated cytotoxicity against viral infected or cancer cells is impaired by obesity. Leptin level is chronically elevated in obesity and has the counter effects on NK cells. Short-term leptin exposure causes lower cytotoxicity of NK cells but long-term leptin exposure has opposite effect. The few studies about phenotype of NK cells in visceral adipose tissue during obesity point on higher production of INF- and expression of NKG2D by NK cells. Further studies of NK cell phenotype in the context of obesity and in particularly in the context of visceral adipose tissue of obese subjects are important for understanding the negative effect of obesity.
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