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Carbohydrate dimers in tumor immunotherapy
Krupová, Monika ; Bezouška, Karel (advisor) ; Ryšlavá, Helena (referee)
Carbohydrate dimers in tumor immunotherapy Monika Krupová (Department of Biochemistry, Faculty of Science, Charles University in Prague) One possible approach to tumor immunotherapy is an activation of killer lymphocytes through specific ligands for their surface receptors. CD69 is a molecule greatly widespread among various cells of haematopoietic origin. Since the physiological ligand for this receptor is still unknown, ligand mimetics are used for modulation of its activity. The mimetics tested in this work are based on monomeric or oligomeric carbohydrated attached through two different chemical groups to the central linker of varying length, giving rise to thiourea and triazole series. The ability to precipitate soluble NKR-P1 and CD69 receptors was evaluated in precipitation assays and the optimal length of the linker for NKR-P1 receptor was found to be decyl. On the other hand, cross-linking of CD69 is not so dependent on the length of the linker. The aim of this work was to describe in vitro effect of the tested compounds on cellular signalization, natural killing of leukemic cell lines and activation-induced apoptosis. Compounds of triazole series containing two disaccharides (GalNAc β1→4 GlcNAc) linked by a linker were found to have the strongest effect on the production of...
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Antigenome defines a selection of mutated tumor peptides driving tumor-specific T-cell response
Hadlová, Petra ; Drbal, Karel (advisor) ; Dibus, Michal (referee)
T cells, as an essential part of the adaptive immune system, play crucial role in eradication of tumor growth. T cells target, interact with and eventually annihilate the tumor cells in antigen- specific (Ag) manner. T cells interact with tumor cells via short epitopes bound to the major histocompatibility complex (MHC) molecules on the tumor cell surface. Tumor specific neoepitopes arise from random somatic mutations and constitute a part of the tumor antigenome. Antigenome comprises of two classes of antigens, tumor specific antigens (TSA) and tumor associated antigens (TAA). TSA are neoantigens carrying neoepitopes unique to each tumor. TAA are self-antigens presented by both tumor cells and non-transformed cells. Each tumor cell is able to develop numerous ways to evade the immune system consisting of T cells, NK cells, macrophages and other mechanisms employed. Despite that immunotherapy has shown a great potential in personalized medicine. The stratification of responsive patients is essential for effective and durable management of therapy in clinical practice. Methods are employed, which study existing reactive T cell clones, somatic mutations present in each patient, role of somatic mutations in tumor development and present neoepitopes. All these patient- specific features facilitate...
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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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Antitumor activity of IL-2 and IL-7 immunocomplexes in combination with αCTLA-4 and αPD-1 mAbs
Hnízdilová, Tereza ; Kovář, Marek (advisor) ; Hájková, Michaela (referee)
Biological activity of IL-2 and IL-7 in vivo is significantly increased when complexed with some of the respective anti-cytokine mAb. Different immune cell subsets can be preferentially stimulated depending on the anti-IL-2 mAb used to complex IL-2. IL-2/anti-IL-2 mAb S4B6 immunocomplexes (IL-2/S4B6) induce preferential expansion of CD122high cells whereas IL-2/anti-IL-2 mAb JES6-1 immunocomplexes (IL-2/JES6-1) highly selectively stimulate CD25high cells in mice. Similarly, IL-7/anti-IL-7 mAb M25 immunocomplexes (IL-7/M25) possess higher stimulatory activity for both naïve and memory CD8+ T cells in vivo in comparison to free IL-7. CTLA-4 and PD-1 molecules are inhibitory receptors which negatively regulate proliferation, survival and effector functions of T cells. Blocking antibodies against these molecules represent promising immunotherapeutic tool for treatment of malignant diseases. We examined possible synergism of IL-2/S4B6 and αCTLA-4 plus αPD-1 mAbs in tumor-bearing mice. We found that the expansion of recently activated CD8+ T cells driven by IL-2/S4B6 was further augmented by αCTLA-4 plus αPD-1 mAbs. However, these two immunotherapeutic approaches did not show synergistic antitumor activity in any mouse tumor model tested. Next, we showed that IL-7/M25 possessed higher biological activity...
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Cytometric assay of antigen-specific T cell response in monitoring of BCG vaccine therapy
Hadlová, Petra ; Drbal, Karel (advisor) ; Kalina, Tomáš (referee)
Bladder carcinoma (BCa) is among the most common carcinomas in the Western world. Despite the availability of effective therapies, there is currently an urgent need to develop a stratification method, which would enable the accurate identification of patients responsive to therapy. In the theoretical part of my diploma project I describe the heterogeneity of BCa and the currently applied immunotherapeutic approaches. I specifically focused on the Bacillus Calmette-Guérin (BCG) vaccine instillation. For decades another use of BCG has been a prophylactic vaccination against tuberculosis (TB) infection. BCG serves as a model treatment because it is highly efficient when prescribed to the responsive patient. However, an effective stratification is yet to be developed for BCa and latent tuberculosis infection (LTBI) diagnosis and/or monitoring. In the experimental part of my project, I developed and tested a 10-parameter panel for T cell- specific activation test (TAT) applicable for a stratification of BCa patients as well as for the detection of LTBI. I tested the panel on positive controls using flow cytometry (FCM) method because it allows for detection and measurement of dozens of markers at a single cell level. It is easily applicable to available urine and blood samples obtained from BCa...
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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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Biological activity of IL-2/anti-IL-2 mAb immunocomplexes in vivo and their terapeutical potential
Hnilicová, Šárka ; Kovář, Marek (advisor) ; Grobárová, Valéria (referee)
IL-2 belongs to the family of c cytokines (IL-2, 4, 7, 9, 15, and 21) which are key regulators of lymphocyte homeostasis and function. They have the potential to promote lymphocyte proliferation and survival and thus overall enhance dominantly adaptive immune response. IL-2 is an autocrine/paracrine soluble factor produced mainly by activated T cells. Interestingly, the in vivo biological activity of IL-2 can be dramatically increased through complexing with certain anti-IL-2 mAbs and such IL-2/anti-IL-2 mAbs immunocomplexes selectively stimulate proliferation of distinct population of immune cells, depending on the clone of anti-IL-2 mAb used. IL-2/S4B6 mAb immunocomplexes are highly stimulatory for CD122high populations (memory CD8+ T and NK cells) and intermediately also for CD25+ populations (Treg and activated T cells), while IL-2/JES6-1 mAb immunocomplexes enormously expand solely CD25+ cells. Thus, IL-2 immunocomplexes possess a broad spectrum of potential therapeutic applications like tumor immunotherapy, vaccination, autoimmune diseases or transplantology.
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Antigenome defines a selection of mutated tumor peptides driving tumor-specific T-cell response
Hadlová, Petra ; Drbal, Karel (advisor) ; Dibus, Michal (referee)
T cells, as an essential part of the adaptive immune system, play crucial role in eradication of tumor growth. T cells target, interact with and eventually annihilate the tumor cells in antigen- specific (Ag) manner. T cells interact with tumor cells via short epitopes bound to the major histocompatibility complex (MHC) molecules on the tumor cell surface. Tumor specific neoepitopes arise from random somatic mutations and constitute a part of the tumor antigenome. Antigenome comprises of two classes of antigens, tumor specific antigens (TSA) and tumor associated antigens (TAA). TSA are neoantigens carrying neoepitopes unique to each tumor. TAA are self-antigens presented by both tumor cells and non-transformed cells. Each tumor cell is able to develop numerous ways to evade the immune system consisting of T cells, NK cells, macrophages and other mechanisms employed. Despite that immunotherapy has shown a great potential in personalized medicine. The stratification of responsive patients is essential for effective and durable management of therapy in clinical practice. Methods are employed, which study existing reactive T cell clones, somatic mutations present in each patient, role of somatic mutations in tumor development and present neoepitopes. All these patient- specific features facilitate...
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Carbohydrate dimers in tumor immunotherapy
Krupová, Monika ; Bezouška, Karel (advisor) ; Ryšlavá, Helena (referee)
Carbohydrate dimers in tumor immunotherapy Monika Krupová (Department of Biochemistry, Faculty of Science, Charles University in Prague) One possible approach to tumor immunotherapy is an activation of killer lymphocytes through specific ligands for their surface receptors. CD69 is a molecule greatly widespread among various cells of haematopoietic origin. Since the physiological ligand for this receptor is still unknown, ligand mimetics are used for modulation of its activity. The mimetics tested in this work are based on monomeric or oligomeric carbohydrated attached through two different chemical groups to the central linker of varying length, giving rise to thiourea and triazole series. The ability to precipitate soluble NKR-P1 and CD69 receptors was evaluated in precipitation assays and the optimal length of the linker for NKR-P1 receptor was found to be decyl. On the other hand, cross-linking of CD69 is not so dependent on the length of the linker. The aim of this work was to describe in vitro effect of the tested compounds on cellular signalization, natural killing of leukemic cell lines and activation-induced apoptosis. Compounds of triazole series containing two disaccharides (GalNAc β1→4 GlcNAc) linked by a linker were found to have the strongest effect on the production of...
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