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Combined immunotherapy of tumors with different expression of MHC class I molecules
Piataková, Adrianna Julia ; Šmahel, Michal (advisor) ; Krulová, Magdaléna (referee) ; Reiniš, Milan (referee)
Immunotherapy experienced ups and downs before being recognized as a paramount therapy for cancer. Evidence from the latest studies revealed that the tumour microenvironment (TME) plays a decisive role in the outcome of immunotherapeutic treatment. In addition, one of the mechanisms used by cancer cells to evade immunosurveillance is reduction of the expression of major histocompatibility complex class I (MHC-I), by which cancer cells become invisible to cytotoxic T lymphocytes (CTLs). Therefore, cancer immunotherapy should involve combined strategies to target both tumour cells and TME from different sites by activating other immune cells in addition to CTLs, such as tumour-associated macrophages (TAMs). This Ph.D. thesis aimed to investigate combined immunotherapy, composed of DNA immunization, immunostimulatory compounds, and an immune checkpoint inhibitor to activate adaptive and innate immunity and inhibit immunosuppression, respectively. For this purpose, murine models related to HPV-16-induced tumours with either reversibly (TC-1/A9 cell line) or irreversibly (TC-1/dB2m) reduced MHC-I expression were used. The development of the TC-1/dB2m clone was a part of this project and this clone was obtained by deactivating the B2m gene. An important focus of the research was the analysis of TAMs isolated from...
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Surface expression of Tim-3 inhibitory molecule on antigen-specific CD8+ T cells expanded in vitro using dendritic cells for cell-based cancer immunotherapy
Svobodová, Hana ; Smrž, Daniel (advisor) ; Funda, David (referee)
Cancer is the second most common cause of death in the world, and the number of people with the disease increases each year. The therapy of the disease currently stands on four pillars; surgery, chemotherapy, radiotherapy, and immunotherapy. Through the past few years, immunotherapy has become the fastest developing treatment modality. However, despite its unprecedented efficacy in some patients, the majority of patients still does not respond to the therapy. Therefore, there is a need to investigate the mechanisms that make immunotherapy inefficient. Cell-based cancer immunotherapy is the treatment modality which uses live ex vivo-produced tumor-targeting immune cells to treat cancer. One of the mechanisms that may compromise its therapeutic efficacy is the expression of inhibitory molecules on the surface of the produced immune cells. Tim-3 is the inhibitory molecule which attracts attention in recent years. Tim-3 expression in the tumor cells and the tumor-infiltrating immune cells is often associated with worse prognosis and more aggressive forms of the disease. However, its role in the in vitro or ex vivo-produced immune cells is difficult to predict. In this work, an in vitro study model which is based on in vitro-produced antigen-specific CD8+ T cells with high expression of Tim-3 has been...
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Significance of Tim-3 protein expression on the surface of acute myeloid leukemia cells
Kořánová, Tereza ; Kuželová, Kateřina (advisor) ; Brdička, Tomáš (referee)
Acute myeloid leukemia (AML) is a cancer disorder of hematopoiesis, characterised by production of dysfunctional progenitor cells of myeloid cell lineage. Mutations provide malignant cells with the ability to proliferate independently of growth factors and to resist to cell death induction. In addition, transformed cells are often capable of escaping the immune system. T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) was originally discovered on the surface of immune cells, where it acts as an inhibitory receptor. Later, Tim- 3 was also found on leukemia cells, but its function on this cell type is much less clear. Upon ligation with galectin-9 (Gal-9), Tim-3 acts on AML blasts as an activating receptor. The Tim- 3/Gal-9 complex signalization stimulates NF-κB, β-catenin, HIF-1, PKC and mTOR pathways, which substitute to some extent the function of growth factors. They support continuous regeneration of leukemic cells, provide stimulatory signals, and further increase the production and secretion of Tim-3 and Gal-9 in a positive feedback loop. An important function of Tim-3 is the transport and localization of Gal-9, which blocks the activation of T lymphocytes by interacting with Tim-3 on their surface, inhibits formation of immunological synapse and execution of effector...
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Surface expression of Tim-3 inhibitory molecule on antigen-specific CD8+ T cells expanded in vitro using dendritic cells for cell-based cancer immunotherapy
Svobodová, Hana ; Smrž, Daniel (advisor) ; Funda, David (referee)
Cancer is the second most common cause of death in the world, and the number of people with the disease increases each year. The therapy of the disease currently stands on four pillars; surgery, chemotherapy, radiotherapy, and immunotherapy. Through the past few years, immunotherapy has become the fastest developing treatment modality. However, despite its unprecedented efficacy in some patients, the majority of patients still does not respond to the therapy. Therefore, there is a need to investigate the mechanisms that make immunotherapy inefficient. Cell-based cancer immunotherapy is the treatment modality which uses live ex vivo-produced tumor-targeting immune cells to treat cancer. One of the mechanisms that may compromise its therapeutic efficacy is the expression of inhibitory molecules on the surface of the produced immune cells. Tim-3 is the inhibitory molecule which attracts attention in recent years. Tim-3 expression in the tumor cells and the tumor-infiltrating immune cells is often associated with worse prognosis and more aggressive forms of the disease. However, its role in the in vitro or ex vivo-produced immune cells is difficult to predict. In this work, an in vitro study model which is based on in vitro-produced antigen-specific CD8+ T cells with high expression of Tim-3 has been...
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