National Repository of Grey Literature 26 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Tolerogenic dendritic cells in immunotherapy of type 1 diabetes
Grohová, Anna ; Špíšek, Radek (advisor) ; Černý, Jan (referee) ; Hrdý, Jiří (referee)
Type 1 diabetes is characterized by chronic hyperglycaemia leading to life-threatening complication. The pathogenetic mechanism of T1D is the abnormal immune reaction destroying β-cell mass in pancreas. The current therapy is based on the administration of subcutaneous insulin. However, this therapy can not prevent the episodes of transient hyperglycaemia. Thus, the high blood glucose influences negatively cellular metabolism and progressively leads to tissue damage. The cellular therapy brings the new strategy allowing the direct modulation of the abnormal autoimmune reaction. This strategy promises more targeting therapy with less adverse effects. In this thesis we discuss two types of immune-suppressive cells which are candidates for cellular therapy in autoimmune diseases. The first part describes the tolerogenic dendritic cells (tDC) and their stable suppressive phenotype in proinflammatory condition. tDC maintain their stable inhibitory phenotype and are able to suppress antigen- specific T-cell proliferation together with the induction of T-regulatory cells. These properties of tDC are very important for potential clinical application. The thesis also reveals the relation between laboratory parameters of T1D patients and suppressive properties of tDC. The second part of the thesis is focused...
Anti-tumor activity and toxicity of HPMA copolymer conjugates bearing cytostatic drug
Tomalová, Barbora ; Kovář, Marek (advisor) ; Smetana, Karel (referee) ; Špíšek, Radek (referee)
7 ABSTRACT In this study, we addressed the biological activity and pharmacological features of selected HPMA copolymer-based drug conjugates. We determined their cytostatic activity in vitro as well as toxicity in vivo and therapeutic effcicacy in mouse tumor models. Assessment of maximum tolerated dose (MTD) of two structurally different HPMA copolymer-based conjugates bearing doxorubicin (DOX) attached via pH-sensitive hydrazon bond (HPMA- DOXHYD ) showed that high molecular weight non-degradable star HPMA-DOXHYD conjugate possesses relatively low MTD ~22.5 mg DOX/kg, while linear HPMA-DOXHYD has MTD ~85 mg DOX/kg. Thus, MTD of linear conjugate is 3.7 times higher than that of the star conjugate. Subsequently, we reported that linear conjugate proved to be more efficient in case of treatment of solid tumor EL4 lymphoma and star conjugate to be superior in case of BCL1 leukemia treatment. We also compared biological activity of star and linear HPMA copolymer-based conjugates bearing docetaxel (DTX) attached via pH-sensitive hydrazon bond (HPMA-DTXHYD ). MTD of star conjugate (~160 mg DTX/kg) was proved to be 4 times higher than MTD od free DTX (40 mg/kg). We were not able to determine MTD of linear conjugate as it exceeded 200 mg DTX/kg (the highest soluble dose we were able to administer as a bolus)....
Dendritic cells in health and disease
Horváth, Rudolf ; Špíšek, Radek (advisor) ; Krejsek, Jan (referee) ; Stříž, Ilja (referee)
During the past decades several spectacular finding s have been made in the field of immunology. Elucidating the functions of the antigen presenting cells (APCs) belong to the most important. Dendritic cells (DCs) represent a specific group of APCs with a unique ability to initiate primary immune responses. Despite the fact that, in vivo, they are very rare and difficult to isolate, DCs came very fast into the focus of scientific interests. Development of novel laboratory techniques facilitated a robust expansion of their research. With time it has been proven that DCs play a pivotal role in initiation, maintenance and control of the immune responses. The extraordinary features of DCs were soon investigated in human clinical trials, where DCs have been particularly used as vectors for vaccination protocols, especially in the treatment of tumors. However, DCs capability to polarize the outcome of immune response and the potential to induce or suppress immunity under specific circumstances led to the idea that they might be also used in the treatment of autoimmune and allergic diseases or in transplantation medicine as well. There is a need to stress that most of the knowledge has been obtained from the in vitro generated DCs, but advanced technological methods bring us the opportunity to study DCs directly...
Toll like receptors and myeloid cells in development and disease
Balounová, Jana ; Filipp, Dominik (advisor) ; Špíšek, Radek (referee) ; Vannucci, Luca Ernesto (referee)
Toll like receptors (TLRs) are germline-encoded pattern recognition receptors (PRRs) that play a central role in host cell recognition and responses to pathogens. Primarily they are responsible for induction and regulation of the innate and adaptive immune responses whereby the effector function is executed chiefly by differentiated myeloid cells. Somewhat unexpectedly, TLRs have been also shown to be involved in direct pathogen sensing by bone marrow-derived hematopoietic stem cells (HSCs) and hematopoietic progenitors when, under inflammatory conditions, the rapid generation of innate immune effector cells that effectively combat the infection is of utmost priority. While it has been recognized that the release of inflammatory cytokines from inflamed tissues along with the changes in proportions of differentiating cells in the bone marrow (BM) as well as the BM niche can nudge the differentiation of adult BM-derived cells towards myeloid cells and granulocytes, a direct role of TLRs expressed by HSCs in this process has been demonstrated only recently. However, whether a similar mechanism operates also during embryonic hematopoiesis is unknown. Here we show that TLRs and their adaptor proteins are functionally expressed during early stages of embryogenesis by short-lived maternally-transferred...
Targeting mitochondria to overcome resistance of breast cancer to therapy
Rohlenová, Kateřina ; Neužil, Jiří (advisor) ; Špíšek, Radek (referee) ; Vítek, Libor (referee)
(EN) Tumours are heterogeneous and consist of multiple populations of cells. The population of cells with tumour-initiating capability is known as cancer stem cells (CSC). Cells with increased stemness properties and elevated resistance to anti-cancer treatment have been shown to be highly affected upon decline of mitochondrial respiration, linking the concept of CSCs to deregulated bioenergetics. Consistently, functional electron transport chain (ETC) is crucial in tumorigenesis. Expression of HER2 oncogene, associated with resistance to treatment in breast cancer, has been connected with regulation of mitochondrial function. We therefore investigated the possibility that manipulation of mitochondrial bioenergetics via disruption of ETC eliminates the conventional therapy-resistant populations of tumour, such as CSCs and HER2high cells. We demonstrate that HER2high cells and tumours have increased complex I-driven respiration and increased assembly of respiratory supercomplexes (SC). These cells are highly sensitive to MitoTam, a novel mitochondria-targeted derivative of tamoxifen, acting as a CI inhibitor and SC disruptor. MitoTam was able to overcome resistance to tamoxifen, and to reduce the metastatic potential of HER2high cells. Higher sensitivity of HER2high cells to MitoTam is dependent on...
Impact of pattern and functional properties of tumor-infiltrating immune cells for clinical outcome of head and neck cancer
Hladíková, Kamila ; Špíšek, Radek (advisor) ; Plzák, Jan (referee) ; Reiniš, Milan (referee)
Head and neck squamous cell carcinoma encompasses a complex and heterogeneous group of malignant diseases. Originally, this tumor type was associated with tobacco and alcohol consumption. However, a significantly expanding subset of tumors associated with oncogenic human papillomavirus infection arising in deep tonsillar crypts was identified within the last decades. Due to the essential role of the immune system in antiviral and anticancer immune response, the prognosis of patients is significantly influenced by the volume, composition and functional capacity of the immune infiltrate. The immunosuppressive landscape of head and neck cancer leads to unfavorable outcome of patients and decreased efficacy of immunotherapy. The response rate to standard treatment is high, however, standard therapy is accompanied by considerable toxicity influencing the quality of life. In 2016, the first immunotherapeutics for the treatment of patients with recurrent squamous cell carcinoma of the head and neck were approved - the anti-PD-1 immune checkpoint inhibitors nivolumab and pembrolizumab. This type of therapy, based on mitigation of immunosuppression, shows strong efficacy and less toxicity in combination with other therapies. Therefore, anti-PD-1 immunotherapy was recently approved in the first-line...
Tumor microenvironment and the importance of anti-tumor immunity for clinical course of human cancers
Partlová, Simona ; Špíšek, Radek (advisor) ; Drbal, Karel (referee) ; Kovář, Marek (referee)
Cancer development and progression vary depending on tumor type, localization, invasion, immunogenicity and the ability of immune system to become activated. There are frequent interactions between tumor cells and immune cells, occuring locally at the site of primary tumor or distally through paracrine signalling of various mediators and cytokines. The main subject of this PhD thesis is to study key factors and aspects of immune response in cancer patients. In the first part, we analyzed immune cells infiltrating tumor tissues of ovarian cancer patients at different stages of disease. We focused on the dynamics of immune response, primarily on frequency of individual T lymphocyte populations in peripheral blood and tumor infiltrating T lymphocytes in tumors of early and advanced stages of ovarian cancer. We found that during disease progression there is a gradual decrease of proinflammatory Th17 and Th1 immune responses and a specific recruitment of regulatory T cells to the tumor site, which results in a significant immune suppression in the tumor microenvironment. In the second part, we demonstrated that the character of immune response in HPV-positive head and neck cancer patients is very different from the patients with tumors not associated with HPV infection. In HPV-positive patients, significantly...
Prognosis and diagnostics in acute myeloid leukemia
Jiráková Trnková, Zuzana ; Jíra, Milan (advisor) ; Černá, Marie (referee) ; Špíšek, Radek (referee)
The main aim of the dissertation was in patients with acute myeloid leukemia to investigate the impact of favorable prognostic chromosomal aberrations and increased expression of a family of multiple drug resistance genes to achieve a complete remission and overall survival, and identify the potential prognostic factors. Experiments were focused on the introduction of routine diagnostics of two prognostically favorable fusion genes, AML1/ETO and CBFbeta/MYH11 and multiple drug resistance gene MDR1. This testing was performed by reverse transcription, PCR and subsequent electrophoretic analysis of its products.
Immunologic and epigenic modulation of gene expression of human leukemia cell lines
Elknerová, Klára ; Stöckbauer, Petr (advisor) ; Špíšek, Radek (referee) ; Škvor, Jiří (referee)
Therapy by monoclonal antibody to CD34 molecule Growth-inhibitory and proapoptotic effect of the monoclonal antibody to CD34 molecule, clone 4H11, were tested on CD34+ leukemic cell lines (MOLM-9, JURL-MK1) and CD34- cell line (PS-1). We have found that the monoclonal antibody to CD34 inhibited the proliferation and induced apoptosis of all CD34+ cell lines tested, however it has similar effect on CD34- leukemic cell line (PS-1) in concentration higher than 32 µg/ml. We did not observe induction of differentiation by anti-CD34 antibody, but a growth arrest of cells in the G0/G1 phase of the cell cycle was detected in CD34+ cell lines. Combinations of anti-CD34 antibody with both type I (α, β) or type II ( ) interferons did not enhance the effects on the cell growth or inhibition of cellular proliferation of the antibody alone. Combinations of anti-CD34 antibody with hematopoietic cytokines or INF-γ did not induced diferentiation. Our data suggest that the monoclonal antibody to CD34 molecule prepared from clone 4H11, after sufficient experimental and preclinical testing on laboratory animals, may provide a new basis for possible targeted antibody therapy of acute or chronic myeloid leukemia. Therapy by histone deacetylase inhibitors Histone deacetylase inhibitors (HDACi) are emerging new class of...
Impact of pattern and functional properties of tumor-infiltrating immune cells for clinical outcome of head and neck cancer
Hladíková, Kamila ; Špíšek, Radek (advisor) ; Plzák, Jan (referee) ; Reiniš, Milan (referee)
Head and neck squamous cell carcinoma encompasses a complex and heterogeneous group of malignant diseases. Originally, this tumor type was associated with tobacco and alcohol consumption. However, a significantly expanding subset of tumors associated with oncogenic human papillomavirus infection arising in deep tonsillar crypts was identified within the last decades. Due to the essential role of the immune system in antiviral and anticancer immune response, the prognosis of patients is significantly influenced by the volume, composition and functional capacity of the immune infiltrate. The immunosuppressive landscape of head and neck cancer leads to unfavorable outcome of patients and decreased efficacy of immunotherapy. The response rate to standard treatment is high, however, standard therapy is accompanied by considerable toxicity influencing the quality of life. In 2016, the first immunotherapeutics for the treatment of patients with recurrent squamous cell carcinoma of the head and neck were approved - the anti-PD-1 immune checkpoint inhibitors nivolumab and pembrolizumab. This type of therapy, based on mitigation of immunosuppression, shows strong efficacy and less toxicity in combination with other therapies. Therefore, anti-PD-1 immunotherapy was recently approved in the first-line...

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