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Effect of bacterial monoassociations (Akkermansia muciniphila) on development of type 1 diabetes and immune parameters in ex-germ-free NOD mice
Němec, Dušan ; Funda, David (advisor) ; Zadražil, Zdeněk (referee)
Type 1 diabetes (T1DM) is an autoimmune condition affecting around 0,4 % of general population and its prevalence is still increasing. T1DM is a multifactorial disease, and it develops under the forces of various environmental and hereditary factors. Gut microbiota is recently one of the most relevant environmental features of autoimmunity, including T1DM. Healthy gut microbiota is characterized especially by its variability. However, there has been an effort to determine critical bacteria that can either drive or suppress T1DM development. Akkermansia muciniphila is among those potentially protective bacteria. This diploma thesis examined changes of immune parameters, such regulatory T cells, NK cells, γδ T cells and expression of IFNγ, IL-10 and IL-17, and their correlation with T1DM onset in A. muciniphila- monoassociated ex-germ-free NOD mice compared to germ-free (GF) and specific-pathogen- free (SPF) controls. Furthermore, the second part of the thesis, NOD-SCID adoptive transfer provided an insight into whether diabetogenic ability of NOD mice-derived splenocytes differ in A. muciniphila vs GF and SPF controls. Minor differences were found in immune parameters among various cell populations, with the most prominent increased IL-10 expression in A. muciniphila-monoassociated mice compared to...
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CRISPR/Cas9 editing of leukemic B-cells: searching for microRNA-155 targets involved in the process of leukemogenesis
Sypecká, Markéta ; Savvulidi Vargová, Karina (advisor) ; Zadražil, Zdeněk (referee)
CRISPR/Cas9 editing of leukemic B-cells: searching for microRNA-155 targets involved in the process of leukemogenesis Introduction: Chronic lymphocytic leukemia (chronic lymphoid leukemia, CLL) is a monoclonal disorder characterized by a progressive accumulation of functionally incompetent B-lymphocytes. CLL is the most common form of leukemia found in adults in Western countries. Course of the disease can differ: some patients die rapidly, within 2-3 years of diagnosis, mainly due to complications from CLL, but most patients live 5-10 years. However, with disease progression significantly increases level of miR-155, which is known as oncomiR. MicroRNAs (miRNAs) represent negative regulators of gene expression. MiR-155 affects genes, which are involved in leukemogenesis and cell cycle. And it is known, that miR-155 suppresses its targets (similarly as other miRNAs). We hypothesized that by gene editing of CLL cells we unblock miR-155 targets and find out correlation between these targets (known and unknown) with CLL leukemogenesis. Methods: We used CRISPR/Cas9 method for gene editing, which enables the deletion of mature miR-155 sequence in the genome of leukemic B-cells. CRISPR/Cas9 plasmid was transferred to the leukemic B-cell cell line HG-3 via nucleofection. Clones with successful transfer of...
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CRISPR/Cas9 editing of leukemic B-cells: searching for microRNA-155 targets involved in the process of leukemogenesis
Sypecká, Markéta ; Savvulidi Vargová, Karina (advisor) ; Zadražil, Zdeněk (referee)
CRISPR/Cas9 editing of leukemic B-cells: searching for microRNA-155 targets involved in the process of leukemogenesis Introduction: Chronic lymphocytic leukemia (chronic lymphoid leukemia, CLL) is a monoclonal disorder characterized by a progressive accumulation of functionally incompetent B-lymphocytes. CLL is the most common form of leukemia found in adults in Western countries. Course of the disease can differ: some patients die rapidly, within 2-3 years of diagnosis, mainly due to complications from CLL, but most patients live 5-10 years. However, with disease progression significantly increases level of miR-155, which is known as oncomiR. MicroRNAs (miRNAs) represent negative regulators of gene expression. MiR-155 affects genes, which are involved in leukemogenesis and cell cycle. And it is known, that miR-155 suppresses its targets (similarly as other miRNAs). We hypothesized that by gene editing of CLL cells we unblock miR-155 targets and find out correlation between these targets (known and unknown) with CLL leukemogenesis. Methods: We used CRISPR/Cas9 method for gene editing, which enables the deletion of mature miR-155 sequence in the genome of leukemic B-cells. CRISPR/Cas9 plasmid was transferred to the leukemic B-cell cell line HG-3 via nucleofection. Clones with successful transfer of...
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The metabolic role of pulmonary arterial fibroblasts in the activation of immune system during development of pulmonary arterial hypertension
Křivonosková, Monika ; Plecitá, Lydie (advisor) ; Zadražil, Zdeněk (referee)
The development of inflammation in the small distal pulmonary vessels plays an important role in the development of pulmonary arterial hypertension (PAH). One of the cell types found in the pulmonary vessels are fibroblasts, which, according to the "outside-in" theory, may be the first to respond to stimuli in the vessel, modulating remodeling of the pulmonary vessels toward the inner layers of the vessel and attracting other immune cells to the site. In addition to inflammation, the so- called Warburg effect also occurs in vessels affected by PAH, in which metabolism shifts toward glycolysis and lactate production. Among other changes, a pro-oxidative state is induced within the cell by mitochondrial metabolism and NADPH oxidase, leading to an imbalance in reactive oxygen species production. We therefore wanted to test whether calf lung fibroblasts with hypoxia-induced PAH have an active inflammasome, with which they would produce mature interleukin 1β (IL-1β) and to clarify the effect of a pro-oxidant environment on this expression. In our in vitro model we have confirmed IL-1β mRNA expression, but we were unable to detect its expression at the protein level. This was consistent with the inability to detect inflammasome activity. We believe that the inability to detect the protein form of IL-1β...
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Studying immune system using MHC II/ EGFP knock-in mouse
Zadražil, Zdeněk ; Černý, Jan (advisor) ; Tlaskalová - Hogenová, Helena (referee)
The immune system is essential for keeping the integrity of multicellular organisms. We were able to make a step forward in studying the complex immune reactions in mammals in vivo and/ or in situ using the major histocompatibility complex (MHC) class II/ enhanced green fluorescent protein (EGFP) knock-in mouse model. Due to the EGFP visualization of MHC II expressing cells we were able to observe antigen presenting cells, which are essential for the onset of immune responses, in their natural environment. Thus, we report some original features of the immune system. We have identified MHC II+ cell clusters with unknown, probably unique function, in the intestine. We have also described MHC II+ cell migration to the lactating mammary gland and tested few hypotheses about the role of this phenomenon for the development of the mammary gland, milk secretion or infant immune system establishment. Lastly, we observed residential macrophages in the cornea. The presence of APCs in the cornea is a very contradictory issue due to the fact that cornea is an immunologically privileged tissue and therefore harbors special immune features. key words: antigen presenting cells (APC), major histocompatibility complex class II (MHC II), enhanced green fluorescent protein (EGFP), immune system, knock-in mouse model
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Cytokines in the effector function of regulatory T cells
Zadražil, Zdeněk ; Holáň, Vladimír (advisor) ; Stříž, Ilja (referee)
Regulatory T cells (Treg) are an important control mechanism within the Immune system (IS). Tregs prevent overactivation of effector T cells or autoreactive cells from invading organism-derived tissues. Treg are characterised by expression of surface molecules, CD4, CD25 and by an intracellular transcription factor forkhead box protein 3 (FoxP3). There are two basic populations of Treg, naturally occuring Treg (nTreg) developing in the thymus and induced Treg (iTreg) rising from CD4+ T cells in periphery, which are also precursors for T helper cells. In spite of an outgoing intensive research, there is still no clear clue which mechanisms are used by Treg to inhibit other effector cells. First in vitro experiments showed, that those mechanisms are of a contact dependent manner and do not use secreted molecules. But in vivo experiments showed the exact opposite. Those studies showed that secretory molecules, such as interleukin (IL)-10, IL-35 or transforming growth factor beta (TGF-β), are important in the effectory phase of Treg. Since the first experiments other distinct mechanisms of supression by Treg cells have been discovered. Those mechanisms seem to be important only in particular situations, particular cell assays or with using of specific experimental models. The reasons for this...
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Regulation of bone formation using osteogenic supplements in an osteoporotic model
Krčmářová, Eliška ; Filová, Eva (advisor) ; Zadražil, Zdeněk (referee)
Osteoporosis is a disease of the bone metabolism which is characterised with a decrease of bone substance. The cause of this disease is the imbalance between the creation of a new bone substance by osteoblasts and the resorption of a bone tissue by osteoclasts, in favour of the bone resorption. The risk group of the development of this disease are women after menopause, who naturally register a decline of the estrogen hormone. Estrogen operates as an inhibitor of proosteoclastic factors such as receptor activator of NFκB ligand (RANKL), interleukin (IL)-1, IL-6 or TNF-α. The imbalance of the bone metabolism can also be caused by a disbalance in the production of Prostaglandin E2 (PGE2) and 1α,25-dihydroxyvitamin D3. They are strong mediators which can both stimulate and inhibit an osteoclastogenesis in vitro in concordance with the conditions of the culture/co-culture. This thesis focuses on the examination of an influence of those mediators (PGE2 in the concentration of 10-6 M and 10-8 M; 1α,25-dihydroxyvitamin D3 in the concentration of 10-8 M and 10-9 M) on the osteoclastogenesis from the rat PBMC at the presence of osteoblasts, with or without the combination of proosteoclastic factors macrophage colony-stimulating factor (M-CSF) and RANKL. Osteoclastogenesis was stimulated if PGE2 and...
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Optimizing chimeric antigenic receptors (CARs) T-cells for immunotherapy of hematological malignancies
Mucha, Martin ; Otáhal, Pavel (advisor) ; Zadražil, Zdeněk (referee)
Immunotherapy based on chimeric antigen receptor (CAR)-expressing T lymphocytes has proven to be highly successful in the treatment of acute lymphoblastic leukemia (ALL), leading to development of CAR-based immunotherapies for other hematologic malignancies. Currently, efforts are underway to refine T cell modifications to make patient treatment more effective. Each time, this modification then needs to be empirically validated in in vitro experiments. We decided to study the effect of the cytokine IL-21 on the antitumor function of CD19-specific CAR T cells using in vitro assays. A construct that co-expressed IL-21 under the control of the inducible NFAT promoter together with CARs against CD19 was introduced into T cells. In a series of experiments, the properties of these cells were compared after coculture with tumor B cell lines and CLL cells obtained from patients. The results showed that CAR T cells that express IL-21 proliferate and activate better, even after repeated stimulation with leukemia cells. In addition to CARs specific against the CD19 molecule, we also investigated CARs specific against the CLL1 molecule, which has been described in the literature as one of the promising targets for the treatment of AML. We prepared CAR T cells against CLL1 producing IL-21. For this purpose, we...
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Identification of novel mechanisms controlling emergency granulopoiesis in hematopoietic stem and progenitor cells
Vaníčková, Karolína ; Alberich Jorda, Meritxell (advisor) ; Zadražil, Zdeněk (referee)
Granulocytes represent the first line of defense against bacteria and fungi. Daily production of granulocytes is sustained by steady state granulopoiesis but under stress (e.g., bacterial infection) this program switches to emergency granulopoiesis (EG) which ensures the production of granulocytes at enhanced and accelerated rates. Very little is known about the regulation of EG. In this thesis, we showed that disruption of the β-catenin-TCF/LEF mediated transcription impairs EG in vivo. Further, we demonstrated that lipopolysaccharide (LPS) administration in mice induces accumulation of active β-catenin in hematopoietic stem and progenitor cells (HSPCs) as early as 4 hours (H) after stimulation, with highest increase at 24H. This effect was at least partially mediated in a niche independent manner, since LPS stimulation in vitro induced β-catenin accumulation in c-Kit+ cells after 2H, with a peak activation at 4H. Using single cell RNA sequencing, we determined the cell cluster dynamics of HSPCs following 4H LPS stimulation. Interestingly, we identified a possible upstream activator of β- catenin in one of the clusters - Wnt10b. Indeed, Wnt10b showed a similar expression pattern as EG master regulator Cebpb and β-catenin activation, following in vitro treatment with LPS. Altogether, our data point...
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Effect of gluten-free diet on potentially regulatory immune mechanisms in human type 1 diabetes
Císařová, Radka ; Funda, David (advisor) ; Zadražil, Zdeněk (referee)
Type 1 diabetes (T1D) is an autoimmune disease, whose incidence is rising every year, and its prevention or a cure does not exist. T1D is influenced by multiple genetic factors but environmental factors represent the major contributor to the recent almost epidemic increase of T1D incidence worldwide, primarily in developed countries. Amongst these factors belong for example enteroviral infections, microbiota dysbiosis or gluten-free diet (GFD). GFD has been proven to have a protective effect in NOD mice, which is a spontaneous model of T1D, and a beneficial effect on glycemic control in humans, when administered after T1D onset. This diploma thesis examined changes of regulatory and potentially regulatory T-cells and their cytokines in peripheral blood mononuclear cells (PBMC) of T1D children, who underwent 12-month intervention trial of GFD. Secondly, the thesis assessed if the influence of GFD on immune regulatory functions can be transferred by colonization of germ-free NOD mice with gut microbiota of these children. We have found that intervention with GFD increases percentage of Tr1 cells and IL-10 producing CD4+ T-cells in PBMC of T1D children. Furthermore, the beneficial effect on immune regulation can be at least partially transferred to NOD mice by the colonization with human microbiota...
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