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Immunomodulation of dendritic cells by adenylate cyclase toxin from B. pertussis
Jáňová, Hana ; Adkins, Irena (advisor) ; Brdička, Tomáš (referee)
Adenylate cyclase toxin (CyaA) produced by the causative agent of whooping cough Bordetella pertussis, is a key virulence factor important for colonization of the host. CyaA targets preferentially myeloid phagocytes expressing CD11b/CD18 integrin. By elevating cytosolic cAMP in the host cells, CyaA interferes with their phagocytic, chemotactic and oxidative burst capacities. Furthermore, CyaA modulates the secretion of cytokines and the maturation state in LPS-stimulated dendritic cells (DC) by affecting the expression of costimulatory molecules. In this study, we investigated the effects of CyaA on the capacity of murine bone-marrow DC to prime CD4+ and CD8+ T cells in response to ovalbumin epitopes delivered by the CyaA-AC- toxoid, as a model antigen. Further, we examined the possible impact of CyaA on the antigen uptake and processing for MHC class I and II-restricted presentation by DC, as we previously observed a decreased T cell stimulatory capacity of CyaA-treated DC in response to soluble ovalbumin. We found out that the high levels of cAMP generated by CyaA in LPS-stimulated DC account for the decreased presentation of ovalbumin epitopes carried by CyaA-AC- toxoid on MHC class I and II molecules, thereby impairing the CD8+ and CD4+ T cell responses. Whereas CyaA did not influence the...
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Comparison of Immune System of Newborns and Adults
Dusilová, Adéla ; Hrdý, Jiří (advisor) ; Zajícová, Alena (referee)
In general, it is possible to characterize neonatal immune system (IS) as immature in comparison to adult IS. From a clinical point of view, newborns show an increased susceptibility to infections. Breastfeeding can contribute to the descent incidence of illnesses, because it supplies the intestinal mucosal system with antibodies of the mother`s origin, important nutrients and other immunoregulatory components. Breast milk compensates decreased newborn's capacity to produce immunoglobulins- especially IgA, that concentration reaches adult levels in two years, but even later (to the pubescent period). Other classes of antibodies are found in cord blood only sporadically except IgG, which is transferred transplacentary. Reduced ability of B lymphocytes to produce antibodies is caused by insufficient expression of surface costimulatory signals of Th2 cells. T lymphocytes are not able to react properly to low doses of stimulators (polyclonal activators - phytoid lectins: ConA or PHA), which bind to T cell receptors in complex with CD3 and proliferate in a response to anti-CD3 monoclonal antibodies. Most of the cord blood T lymphocytes display "naive" phenotype CD45RA. During intrauterine development, neonatal IS is in contact with mother IS and because a pro-inflammatory Th1 response could lead to...
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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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Recombinant expression and studies on DCL-1, receptor of dendritic cells
Pospíšilová, Eliška ; Bezouška, Karel (advisor) ; Novák, Petr (referee)
Recombinant expression and studies on DCL-1, receptor of dendritic cells Eliška Pospíšilová Charles University in Prague, Faculty of Science, Department of Biochemistry ABSTRACT Dendritic cells, which could be found in large numbers in many tissues, exprime C-type lectine receptor DCL-1 (in CD nomenclature CD302) on their surface. This molecule belongs to the class one transmembrane proteins. N-terminal sequence a C-type lectin-like domain (CTLD) it has on the extracellular side. Whereas the C-terminus, which contains potential phosphorylation site and signals for intracellular transport, is in the cytosol. As the sequence of this protein is highly conserved through all mammalian species, it is likely to play an important role in the immune system. Despite this fact, the DCL-1 molecule is still poorly investigated. This work deals with the extracellular part - especcially with the CTLD containing part - of the DCL-1 receptor. To learn more about this molecule, we attempted its recombinant expression in bacteria. We used pET-30a(+) based vector pDCL1E, and bacterial cells E. coli BL21 (DE3) Gold, which produced the target protein in the form of inclusion bodies into the cytoplasm. Therefore conditions for in vitro renaturation were optimalized, and it was prooved that the protein had native conformation...
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The effect of extreme physical exertion on the percentage of dendritic cell subpopulations in professional athletes as correlated with change in adrenaline levels
Fischerová, Barbara ; Kolář, Pavel (advisor) ; Radvanský, Jiří (referee)
The main goal of this tesis is to describe changes in representation of various subpopulations dendritic cells (myelogenic and plasmocytoigenic) in peripheral blood after intense physical stress and to review their activation status. Early count changes and changes of function of basic elements of cellular immunity after a sport load was described, whereas a behaviour of circulating dendritic cells hasn't been studied yet. The amount and the stage of differentation of dendritic cells was specified by analysis of blood samples taken before and after the load. According to the result of the tesis the reaction to extreme physical load had two effects. The amount of dendritic cells was increased, whilst the expression of kostimulative molecules (their activation) was decreased. Described changes support an opinion, that physical load initates reaction to a danger of body damage. Powered by TCPDF (www.tcpdf.org)
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Dendritic cells and autoimmune diseases with a view to type 1 diabetes mellitus
Chrástová, Iveta ; Štechová, Kateřina (advisor) ; Krulová, Magdaléna (referee)
Dendritic cells (DC) are professional antigen-presenting cells (APC) that play an essential role in the induction of immune responses. DCs develop from CD34+ hematopoietic stem cells in bone marrow and their role is uptake, processing and presentation of antigens to T cells. DCs can be divided into two distinct subset of cells, myeloid a plasmacytoid DCs. Myeloid DCs (mDC) develop from hematopoietic cells in the presence of GM-CSF and TNF-α or from monocytes in the culture with GM-CSF and IL-4, then with CD40L they mature and produce a large number of IL-12, which is important in driving CD4+ T cell to type Th1. The development of pDC is CD40L and IL-3 dependent and Flt3-L supports this process as well. The essential role of pDC is that they secrete a large amounts of type I IFN in the responses to viruses and so they maintain the antiviral stage. To recognize the viruses pDC express Toll-like receptors 7/9. DCs have on the surface also other groups of receptors, e.g. C-type lectin-like receptors, RIG-I-like receptors and NOD-like receptors. They play the role in the various diseases, mostly autoimmune diseases, in which the immune system recognizes self tissues and activates against them the immune response. Dendritic cells function is that they are competent to activate T cells, in the most cases...
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Monitoring of immune parameters during anti-tumor immunotherapy
Bílková, Pavla ; Palich Fučíková, Jitka (advisor) ; Fialová, Anna (referee)
Dendritic cells are the most effective antigen presenting cells in humans, they stimulate naive T lymphocytes and thus initiate specific immune response. The discovery of dendritic cells and understanding of their functions contributed to the idea of usingdendritic cells for the treatment of cancer. Anti tumor immunotherapy is a therapeutic strategy that aims to induce and maintain immune responses against tumor cells. Currently, immunotherapy based on dendritic cells has strong position among other anti cancer therapies and seems to be a promising therapeutic option for patients with tumors. In this work, I evaluated the effectiveness of treatment in patients with prostate cancer treated with immunotherapy based on dendritic cells. I focused on the detection of antigen specific T lymphocytes in peripheral blood against tumor antigens, PSA, NY ESO 1, MAGE A1 and MAGE A3. Using a 3 day standard protocol for the detection of antigen specific T cells using intracellular cytokine staining we were able to detect only a small percentage of this minor population. Only after extension of the protocol, we increased the sensitivity setting and we detected a significantly increased frequency of antigen specific T lymphocytes in the peripheral blood after one year DC vaccines application.
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Immunologic Characteristics of Cord Blood in Children with Increased Risk of Allergy Development Preventive Use of Probiotics
Hrdý, Jiří ; Prokešová, Ludmila (advisor) ; Tlaskalová - Hogenová, Helena (referee) ; Ulčová-Gallová, Zdeňka (referee)
Allergy is one of the most common diseases. Identification of early prognostic markers pointing to an increased risk of allergy development is therefore of increasing importance. Cord blood represents an easily attainable clinical material for searching for prognostic markers signalizing future allergy development. Proportions of Th1 cytokines, Th2 cytokines and regulatory cytokines were tested in cord blood of children of allergic mothers (children in relatively high risk of allergy development) in comparison with cord blood of children of healthy mothers (low risk children). Also the activities of lymphocytes, dendritic cells (DC) and regulatory cells (Tregs) were compared in children of healthy and allergic mothers. The generally increased activity of both in vitro stimulated and non-stimulated mononuclear cord blood leukocytes was proved in children of allergic mothers in comparison with low risk children. The increased activity of DC of high risk children was detectable only after polyclonal stimulation. Significantly less pronounced functional properties of cord blood Tregs were found in children of allergic mothers when compared with children of healthy mothers. The increased reactivity of lymphocytes and DC together with the decreased activity of Tregs can support an easier...
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Immune system dysregulation in type 1 diabetes
Paračková, Zuzana ; Šedivá, Anna (advisor) ; Filipp, Dominik (referee) ; Vlková, Marcela (referee)
Type 1 diabetes (T1D) is an autoimmune disease with multifactorial aetiology that involves an attack of self-reactive cytotoxic CD8 lymphocytes on insulin-producing beta cells in the pancreas. In the T1D pathophysiology, both innate and adaptive immunity mechanisms cooperate in the development of inflammation leading to autoimmune destruction. Autoreactive T lymphocytes are the canonical destructors of the beta cells, and B cells produce autoantibodies; the innate immunity cells are considered the initiators of the pathological autoimmune reaction by promoting T and B cell activation. Here, we provide evidence of both innate and adaptive immunity cell types dysregulation in patients with T1D, and that these changes occur before the onset of the disease. The changes in T regulatory lymphocytes (Tregs) and B cell subpopulations occur already in asymptomatic T1D first-degree relatives. During the first year after the onset of the disease, there is a gradual decrease in the neutrophil numbers in the periphery, which probably infiltrate the pancreas. We have focused more closely on the innate immunity dysregulation and its contribution to T1D pathogenesis. Initially, we describe that neutrophil products called neutrophil extracellular traps (NETs) are able to induce IFNγ-producing T cells through...
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