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The effect of aspartate β-hydroxylase inhibition on immune reactions
Krausová, Kateřina ; Šmahel, Michal (advisor) ; Filipp, Dominik (referee)
Aspartate β-hydroxylase (ASPH) is an enzyme that contributes to tumor progression by enhancing the proliferation, migration and invasiveness of cancer cells. Its expression is mostly negligible in normal cells, whereas it is often overexpressed in cancer cells. An inhibitory effect of ASPH on immune cells, specifically on natural killer cells, has also been demonstrated. Thus, the ASPH enzyme could be a new target for cancer immunotherapy. The aim of this thesis was to show the effect of ASPH inhibition on the immune response. Firstly, it was found that ASPH inhibition contributes to the anti-tumor effect of DNA vaccination. The reduction of tumors induced by ASPH inhibition in combination with DNA vaccination was shown to be mainly caused by CD8+ T lymphocytes. Subsequently, the specific activation of T lymphocytes was confirmed by the ELISPOT assay. In case of non-specific activation of T lymphocytes, ASPH inhibition had no effect on the direct activation of CD8+ T lymphocytes. Finally, it was found that plasmacytoid dendritic cells did not contribute to CD8+ T lymphocyte activation after ASPH inhibition. Thus, the results demonstrate that inhibition of ASPH contributes to the activation of adaptive immunity induced by DNA vaccination, but the mechanism of this activation remains unknown.
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Interaction between NKT and myeloid derived suppressor cells and antitumour immunity
Straňavová, Lucia ; Reiniš, Milan (advisor) ; Holáň, Vladimír (referee)
Myeloid- derived suppressor cells (MDSCs) are a heterogeneous population of cells, which plays an important role in the suppression of anti-tumor immune responses. NKT cells represent an additional heterogeneous cell population that plays a crucial role in the regulation of immune responses. It shows that MDSCs and NKT cells may be similar to other populations imunoregulatory cells interact with each other and influence their functions. These interactions are important regulatory factor that may contribute to activation and to suppress anti-tumor immunity. Through interactions with type I NKT cells could differentiate these immunosuppressive MDSCs to immunogenic APC, which could form the basis for immunotherapeutic vaccine. All interactions between the NKT and MDSCs but have a positive effect of imunoregulatory. Interaction between MDSCs and CD4 + NKT cells II. type are immunosuppressive and may subsequently suppress the activity of cytotoxic T-lymphocyte (CTL). In some tumor models it was found that the immunosuppressive nature may also be interactions between MDSCs and type I NKT cells He had, however, alleviate the use of all-trans-retinol acid (ATRA), which induces differentiation of MDSCs.
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Immunogenic cell death in tumor specimens in the clinics
Fejfarová, Adéla ; Drbal, Karel (advisor) ; Büchler, Tomáš (referee)
Tumor development and growth are under the control of the immune system in the human body. Danger-associated molecular pattern (DAMP) molecules trigger the anti-tumor response by binding to pattern recognition receptor (PRR) on myeloid cells which in turn activate an adaptive immune system. DAMP molecules are released from cancer cells during a process of immunogenic cell death (ICD) which is a form of regulated cell death (RCD). ICD is induced by a variety of treatments in experimental settings as well as by therapeutic modalities commonly used in medicine. A typical DAMP marker of ICD is calreticulin which is translocated from the endoplasmatic reticulum to the plasma membrane attached to the CD91 receptor. Another marker is the nuclear protein HMGB1 which is released into the tumor environment at the later stage of ICD. This bachelor thesis describes a variety of detection methods and the results of DAMP externalization after ICD induction in vitro in cancer cell lines and in tumor specimens from cancer patiens. Moreover, the link between DAMP molecules and cancer patient survival is discussed. Last, it also summarizes the current status of clinical trials concerning ICD. Keywords tumor, antitumor immunity, cell death, adjuvans, DAMP, chemotherapeutics, immunogenic cell death, clinical trials
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Microbiota as a modulator of carcinogenesis
Benešová, Iva ; Kverka, Miloslav (advisor) ; Krulová, Magdaléna (referee)
Many studies show the ability of gut microbes to modulate the anti-tumour immune response by direct triggering the immune cells or by bacterial metabolites. Interestingly bacteria may even migrate to the tumour tissue and orchestrate the immune response on site. These anti-tumour effects can be improved by the administration of immune checkpoint inhibitors (ICI). Notably, some microbial effects occur only in the presence of ICI. On the contrary, microbiota may also promote tumour growth and negatively impact the effects of ICI therapy. We have disrupted the gut microbiota homeostasis by antibiotics (ATB) to study the effects of gut microbiota on the ICI. This disturbance led surprisingly to reduced tumour growth and enhanced pro-inflammatory immune response not only in the gut but also within the tumour tissue, where especially IFN-γ orchestrated the anti-tumour immune response. Importantly the anti-tumour immune response could be transferred through colonisation of germ-free mice by ATB-changed gut microbiota if concomitantly anti- programmed cell death protein 1 (αPD-1) monoclonal antibody was administrated. These mice had elevated levels of segmented filamentous bacteria (SFB), which induced systemic immune response with increased expression of IL-17 and elevated amounts of Th 17 cells,...
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Immunogenic cell death
Šímová, Michaela ; Drbal, Karel (advisor) ; Javorková, Eliška (referee)
According to the danger model, the immune system is activated by endogenous molecules known as danger-associated molecular patterns (DAMP) that are externalized from the interior of a dying cell to the cell surface or released into the extracellular space. Due to the loss of plasma membrane integrity a necrotic cell death as well as several types of proinflammatory programmed cell death are considered to be immunogenic, whereas apoptosis, on contrary, has been initially defined as a tolerogenic type of cell death. However, under certain circumstances, the immune response can be initiated by an apoptotic cell after exnternalization of DAMP molecules by newly described secretory pathways. This phenomenon was observed on tumor cells as a result of some widely used therapeutic modalities and is known as immunogenic cell death (ICD). Nomenclature of selected types of cell death is part of this thesis. The aim of this bachelor thesis is to provide an evidence of the experimental support for ICD theory during in vivo initiation of the immune response. I will evaluate the correlation between ICD and the induced exposure of DAMP molecules on the surface of tumor cells or their secretion to the extracellular space.
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Genotoxic stress and senescence in tumour cells: impact on the tumour growth and anti-tumour immunity.
Sapega, Olena ; Reiniš, Milan (advisor) ; Brábek, Jan (referee) ; Šmahel, Michal (referee)
Premature cellular senescence is the process of permanent cell cycle arrest in response to various inducers, such as DNA damage, oxidative stress, chemotherapy agents, and irradiation. Senescent cells produce and secrete numbers of cytokines, chemokines, growth factors, which compose specific senescence-associated secretory phenotype (SASP). Senescence is considered to be an important barrier against tumor progression. On the other hand, senescent cells can also exert protumorigenic effects in their microenvironment. Based on this concept, the major aim of this thesis was to determine tumor cells senescence in terms of different inducers, namely chemotherapeutic agent docetaxel (DTX) and cytokines IFNγ and TNFα, and to demonstrate the role of immunotherapy in senescent cells elimination. Our results show that DTX-induced senescent cells can exert a tumor-promoting effect when co-injected with proliferating cells in mice. Importantly, we demonstrate that IL-12-based immunotherapy suppresses senescence-accelerated tumor growth. These results suggest that IL-12-based immunotherapy can be effectively used in anti-tumor therapy mainly in a case when the microenvironment is altered by the presence of tumor senescent cells. On the other hand, the data we obtained in vitro show that bystander or...
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Modification of murine tumor cell lines with CRISPR/Cas9 system and their characterization
Lhotáková, Karolína ; Poláková, Ingrid (advisor) ; Brábek, Jan (referee)
MHCI molecules are constitutively expressed in all nucleated cells and play a key role in antigen presentation to CD8+ T lymphocytes. One of the tumor immune evasion strategies is MHCI expression downregulation. This leads to an impaired recognition of tumor antigens by CD8+ T lymphocytes that are unable to start the immune response. Since the MHCI expression downregulation occurs in up to 90 % of some tumors it is neccesary to have a clinical relevant tumor model without a MHCI surface expression that would be used for testing of immunotherapeutic approaches. This thesis describes a production of new model cell lines of TC-1 tumor cells with irreversibly downregulated MHCI. That was achieved by an inactivation of B2m, which is a part of MHCI, by gene editing using CRISR/Cas9. The B2m inactivation was confirmed by flow cytometry, western blot and sanger sequencing of single alleles. The inactivation slowed down the cell growth for both in vitro and in vivo. The cell metastatic activity was not affected. The tumors established by cells without the B2m expression are not sensitive to DNA vaccine against HPV16 E7 oncoprotein by a pBSC/PADRE.E7GGG vaccine. The main effector function against these tumors possess the NK1.1+ cells. In a therapeutic vaccination experiment it was repeatedly achieved of...
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Immunogenic cell death
Šímová, Michaela ; Drbal, Karel (advisor) ; Javorková, Eliška (referee)
According to the danger model, the immune system is activated by endogenous molecules known as danger-associated molecular patterns (DAMP) that are externalized from the interior of a dying cell to the cell surface or released into the extracellular space. Due to the loss of plasma membrane integrity a necrotic cell death as well as several types of proinflammatory programmed cell death are considered to be immunogenic, whereas apoptosis, on contrary, has been initially defined as a tolerogenic type of cell death. However, under certain circumstances, the immune response can be initiated by an apoptotic cell after exnternalization of DAMP molecules by newly described secretory pathways. This phenomenon was observed on tumor cells as a result of some widely used therapeutic modalities and is known as immunogenic cell death (ICD). Nomenclature of selected types of cell death is part of this thesis. The aim of this bachelor thesis is to provide an evidence of the experimental support for ICD theory during in vivo initiation of the immune response. I will evaluate the correlation between ICD and the induced exposure of DAMP molecules on the surface of tumor cells or their secretion to the extracellular space.
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Significance of MHC class I molecules in antitumor immunity
Lhotáková, Karolína ; Poláková, Ingrid (advisor) ; Horníková, Lenka (referee)
The main function of the major histocompatibility complex class I (MHC I) glycoproteins is to present antigenic peptides to CD8+ T lymphocytes. Majority of the peptides displayed by this complex come from cell protein degradation and CD8+ T lymphocytes do not respond to them. Tumor development leads to alterations in protein production and new epitopes are generated which impacts peptide repertoire presented by MHC I glycoproteins on the cell surface. Peptides originated from tumor antigens activate CD8+ T lymphocytes and induce anti-tumor immune responses. Decreased surface expression of MHC I molecules is a common phenomenon in tumor cells that prevents effective immune response. As appropriate MHC I expression level on tumor cells is needed for their effective killing by T cell-mediated immune response, downregulation of the MHC I expression may lead to the selection of tumor cells with decreased MHC I level. This downregulation can be either reversible or irreversible, affecting not only the expression of genes encoding the light and heavy chains of MHC I molecules, but also genes of the antigen-processing machinery (APM). Immunotherapeutics focused on the induction of surface expression of MHC I molecules often have other unfavorable impacts on the immune system. Therefore, a new approach is...
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Subpopulations of lymphocytes in patients with prostate cancer during the immunotherapy by dendritic cell vaccine
Volmová, Martina ; Lašťovička, Jan (advisor) ; Palich Fučíková, Jitka (referee)
The bachelor thesis looks into the issue of cancer immunotherapy and it deals with possible use of immunotherapy by dendritic cell vaccine in patients with prostate cancer, which is now in phase I/II of clinical trials on the Department of Immunology at Faculty hospital Motol. The target of the practical part was to cope with the technology of preparation of blood samples and their measurement by means of the flow cytometry, with subsequent data evaluation and processing. The highlight of this work was the statistical evaluation of obtained data of lymphocyte subpopulations levels in peripheral blood, and their possible correlation with disease progression. The main subject of the research were subpopulations CD3 +, CD4 +, CD8+ , CD16+ , CD19+ and HLA-DR+. The monitoring of these subpopulations in patients treated by dendritic cell vaccine showed the decrease of both leukocyte and lymphocyte levels, reduction of CD4/CD8 index, decrease of relative and absolute numbers of CD4+ cells and significant decrease of both relative and absolute B lymphocyte numbers during the progress of the disease. Powered by TCPDF (www.tcpdf.org)
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