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Spontaneous Regression of Melanoma in Pigs of the MeLiM Strain
Plánská, Daniela
Melanoma is a skin tumour arising from melanocytes - skin cells bearing pigment melanin. Melanoma belongs among immunogenic tumours, which is probably associated with a relatively high incidence of partial spontaneous regression (SR). Melanoma-bearing Libechov Minipigs (MeLiM) represent a specially bred animal model that is mostly affected by nodular melanomas, which fully regressed in about 2/3 of the affected animals. Our interest was to examine immune response (associated with melanoma cell destruction) and the role of proteins related to the extracellular matrix (reflecting tissue remodeling) during SR of MeLiM melanoma. We performed an extensive time-lapse study of skin melanomas taken from individuals of the MeLiM strain at 3, 4, 6, 8, 10, 12, 20 and 32 weeks (5-10 samples in each age category) in which we immunohistochemically detected the expression of collagen IV, laminin, fibronectin, tenascin C, as well as MMP-2 and we monitored the proportion of basic immune subpopulations in blood and tumour by flow cytometry. The higher expression of collagen IV, laminin and MMP-2 positively correlated with the appearance of melanoma cells. The expression of collagen IV and laminin indicates a possible survival of tumour cells due to the interaction with these proteins, the presence of MMP-2 in these...
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Novel methods of treatment of B cell malignancies based on immunotherapy with genetically modified T cells
Novotná, Natálie ; Otáhal, Pavel (advisor) ; Šmahel, Michal (referee)
CAR T cell therapy represents a promising method in treatment of hematological malignancies. Gene immunotherapy uses modified T cells that express a chimeric antigen receptor (CAR) on their surface. Modified T lymphocytes are able to recognize and destroy target cells based on specific surface markers. Although CAR T cell therapy is used in clinical practice, there is a number of limitations that reduce its effectiveness. The aim of this thesis is to explore new possibilities of making the entire therapy more efficient through endogenous secretion of interleukins (IL-7, IL-15, IL-21) under the control of inducible promoters, and thus to strengthen the persistence and expansion of CAR T cells in vivo. For this purpose, inducible expression systems containing the gene for CAR19 receptor specifically recognizing the CD19 molecule and the interleukin gene located under inducible NFAT or NR4A promoters, were constructed. The assembled vectors were electroporated into PBMC cells using the PiggyBac transposon system to achieve stable expression in T lymphocytes. After co-cultivation with RAMOS cell line, data were obtained by measurement on a flow cytometer and the ELISA method. Based on the results, it is evident that stimulated CAR T cells are able to generate higher concentrations of interleukins,...
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Mechanisms of antigen presentation in the etiopathogenesis of celiac disease
Hudec, Michael ; Černá, Marie (advisor) ; Hrdý, Jiří (referee) ; Slavčev, Antonij (referee)
1 ABSTRACT Celiac disease (CeD) is a chronic autoimmune disease that develops as a response of the immune system to the presence of gluten in the small intestine. CeD is manifested not only by classic intestinal symptoms: abdominal pain, constipation or diarrhea, as well as complex less common symptoms: anemia, osteoporosis, psychiatric disorders or menstrual cycle disorders. HLA risk alleles predisposing to origin of celiac disease are HLA-DQ2 (DQA1*05:01 / DQB1*02:01) and HLA-DQ8 (DQA1*03:01 / DQB1*03:02). There are other celiac disease-associated polymorphisms outside of HLA locus (6p21.3) that are located in 5q32 and 19p13 regions with unclear connection to CeD development. HLA class II glycoproteins are expressed on antigen presenting cells (APC) that include dendritic cells, macrophages and B cells. Monocytes are one of several possible dendritic cell precursors that circulate in the bloodstream. Deviations in the frequency of intermediate monocytes are directly associated with autoimmune disorders such as Crohn's disease or rheumatoid arthritis. It is known that the monocytes of CeD patients show pro-inflammatory reaction in the presence of gluten. It means that, in the context of CeD, the response to gluten arises earlier than the activation of gluten-specific T cells. The conventional way of direct...
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Spontaneous Regression of Melanoma in Pigs of the MeLiM Strain
Plánská, Daniela ; Horák, Vratislav (advisor) ; Smetana, Karel (referee) ; Bartůňková, Jiřina (referee)
Melanoma is a skin tumour arising from melanocytes - skin cells bearing pigment melanin. Melanoma belongs among immunogenic tumours, which is probably associated with a relatively high incidence of partial spontaneous regression (SR). Melanoma-bearing Libechov Minipigs (MeLiM) represent a specially bred animal model that is mostly affected by nodular melanomas, which fully regressed in about 2/3 of the affected animals. Our interest was to examine immune response (associated with melanoma cell destruction) and the role of proteins related to the extracellular matrix (reflecting tissue remodeling) during SR of MeLiM melanoma. We performed an extensive time-lapse study of skin melanomas taken from individuals of the MeLiM strain at 3, 4, 6, 8, 10, 12, 20 and 32 weeks (5-10 samples in each age category) in which we immunohistochemically detected the expression of collagen IV, laminin, fibronectin, tenascin C, as well as MMP-2 and we monitored the proportion of basic immune subpopulations in blood and tumour by flow cytometry. The higher expression of collagen IV, laminin and MMP-2 positively correlated with the appearance of melanoma cells. The expression of collagen IV and laminin indicates a possible survival of tumour cells due to the interaction with these proteins, the presence of MMP-2 in these...
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Úloha osy PD-1/PD-L1 při infekci \kur{Borrelia burgdorferi} u myší
PALOUNKOVÁ, Anna
Borrelia burgdorferi, the causative agent of Lyme disease, induces upregulation of inhibitory immune checkpoint PD-L1 in mice. We studied if the blockade of PD-1/PD-L1 axis by neutralizing antibodies influences the proliferation of T lymphocytes and cytokine milieu in imunological synapsis between murine dendritic cells and T cells in vitro.
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Tumor Specific Signaling in T-Cell Lymphoma
Kulinich, Viktoriia ; Havránek, Ondřej (advisor) ; Kužílková, Daniela (referee)
T lymphomas are malignant tumors arising from T cells; they represent a rare variant of non-Hodgkin's lymphomas. As in other cancers, tumor T cells need to modify their signaling to support their growth and survival. T-lymphoma tumor cells are capable to adapt various signaling cascades important also in normal healthy T cells to their benefit. The aim of this work is to summarize tumor-specific signaling typical for different types of T-cell lymphomas; both, identical to the signaling of normal T lymphocytes and altered by tumor specific somatic mutations. Detailed focus is on T lymphoma most frequent and important alterations and signaling pathways. These are specifically alterations of signaling pathways associated with T-cell receptor, JAK/STAT cytokine signaling, and Notch signaling. These pathways are particularly important for the differentiation and growth of T lymphocytes in general, therefore, it is not surprising that these pathways are also often pathologically activated or deactivated in tumor cells. Keywords: lymphocytes, non-Hodgkin lymphomas, T-cell receptor, leukemia, JAK/STAT signaling, Notch signaling, oncogenic signaling pathways
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Mechanisms of the tolerance and homeostasis of immune cells
Tsyklauri, Oksana ; Štěpánek, Ondřej (advisor) ; Černý, Jan (referee) ; Froňková, Eva (referee)
The ability of the immune system to tolerate self-antigens while mounting appropriate responses to pathogens is indispensable for the survival of the organism. Despite years of research, many details of the mechanisms of self-tolerance are still not well understood. The objective of this thesis is to extend our knowledge of the mechanisms of immune tolerance. The core of the PhD thesis consists of five publications related to two main research directions. The first one addresses the mechanisms of peripheral immune tolerance established by regulatory T cells (Tregs). We showed that Tregs increase the quorum of self-reactive CD8+ T cells required for the induction of autoimmunity. In addition, we identified a novel subset of antigen-stimulated CD8+ T cells, which expand in the absence of Tregs. We called them super-effector T cells. We revealed that the administration of IL-2 phenocopies the absence of Tregs, i.e., it induces super- effector T cells, and enhances CD8+ T cell response in autoimmunity and cancer. Our results provide strong evidence that the major suppressive mechanism of Tregs is limiting IL-2 availability for CD8+ T cells. Furthermore, in a collaborative project, we have shown that MyD88 signaling in thymic epithelial cells contributes to the development of Tregs and thus to the...
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Influence of tumor microenvironment, cellular and humoral immunity on cancer pathogenesis.
Špaček, Jan ; Závadová, Eva (advisor) ; Petráková, Katarína (referee) ; Kopečková, Kateřina (referee)
Cancer is the second leading cause of death in the Czech Republic. Breast cancer and colorectal cancer have relatively high mortality rate. One of the areas of current clinical research in oncology is the study of prognostic biomarkers, which aims to optimize the decision-making process for a patient. Immune response and processes in the tumor microenvironment have been shown to influence to a large extent the biological nature of the tumor in terms of its aggressiveness and ability to metastasize in the host's body. There are certain tumors that could induce a strong immune response, while others do not. The ability to induce an anti-tumor cell response and to attract specific lymphocyte subpopulations directly into tumor tissue has been shown to be very closely related to the prognosis of cancer patients. There is evidence and correlation of the presence of so-called tumor infiltrating lymphocytes in tumor tissue and overall patient survival. Stratification of cancer patients based on immuno-predictors both in the plasma and directly in the tumor microenvironment makes it possible to identify suitable candidates for rediscovered modern anti-tumor immunotherapy, which can already be considered a standard therapeutic modality. In our projects, we focused on the identification of biomarkers that...
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The role of innate lymphoid cells in influenza virus infection
Mouyabi, Flaviancia ; Hrdý, Jiří (advisor) ; Kössl, Jan (referee)
Innate lymphoid cells (ILCs) are recently discovered group of innate immune cells. They do not have antigen-specific receptors but they can be activated by cytokines similarly to T lymphocytes. ILCs have a crucial role in the regulation of inflammation, tissue repair, containment of commensals, anti-infection immunity and regulation of tissue homeostasis. The presence of mouse and human ILCs can be detected in the lung during and after influenza virus infection when ILCs contribute to the restoration of damaged lung parenchyma. ILCs directly or indirectly provide protection against viral infections by secretion of various cytokines and co-operation with other cells (e.g. T cells, macrophages). Overall, lung ILCs are important in immune responses and tissue homeostasis, but further studies on this topic are needed to fully understand their role. The aim of this thesis was to specifically characterize these cells, focus on their function in the lung, and describe their role in the course of influenza virus infection.
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New chimeric antigen receptor (CAR) for therapy of human cytomegalovirus (HCMV) infection
Kroutilová, Marie ; Němečková, Šárka (advisor) ; Forstová, Jitka (referee)
Human cytomegalovirus (HCMV, Herpesviridae) can cause severe complications in the infected individuals undergoing hematopoietic stem cell transplantation. Nowadays, these patients are treated using antivirotics or HCMV-specific T cells derived from the seropositive graft donor. This study explored the possibility of redirecting HCMV-non-specific T cells from a seronegative donor towards HCMV-infected cells via chimeric antigen receptor (CAR), i.e. artificially designed T cell receptor. Viral glycoprotein B (gB) has been selected as a target for this receptor. Published sequence of a single chain variable fragment of a human antibody was used for the design of the CAR against gB (gBCAR). After the verification of production and surface localization in cell lines, gBCAR was being introduced into human T cells via lentiviral vectors. Human fetal lung fibroblasts (LEP) infected with HCMV were used as target cells after the expression of gB at their surface was demonstrated. gBCAR functionality was evaluated by the incubation of modified T cells with infected cells and subsequent analysis of media for IFNγ concentration, which was significantly higher in the setting of gBCAR T cells incubated with HCMV-LEP than in the control incubations. The results obtained show the specificity of gBCAR against...
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