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Effect of diabetogenic autoantigens on the cytokine production of peripheral blood mononuclear cells from type 1 diabetic patients
Labiková, Jana ; Štechová, Kateřina (advisor) ; Holáň, Vladimír (referee)
5 Abstract Type 1 diabetes (T1D) is a serious organ-specific autoimmune disease characterised by irreversible destruction of pancreatic β-cells by immune system. This process results in an absolute insulin deficiency. Both genetical predisposition and environmental factors influence the development of the disease. β-cell destruction is mediated by cellular components of an immune system. Proinflammatory Th1 response is considered as most pathological. Autoimmune destruction of β-cells can be identified by the detection of specific serum autoantibodies a long time before the T1D clinical onset. Currently, there is no efficient cure available to prevent or at least to delay the destructive insulitis. This diploma thesis describes the influence of synthetic diabetogenic autoantigens GAD65 and IA2 on the cytokine response of peripheral blood mononuclear cells (PBMC) obtained from T1D patients with regards to their antibody profile. The study has been carried out on patients with confirmed T1D diagnosis who tested positive for anti-GAD65 and/or anti-IA2 autoantibodies. By using flow cytometry we measured the cell type ratio in PBMC samples. The cells have been stimulated by three different concentrations of antigens and their IFNγ and IL-17 production has been detected by ELISPOT assay. In the case of both...
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Cord blood T regulatory cells and their association with development of type 1 diabetes
Norková, Jindra ; Štechová, Kateřina (advisor) ; Černý, Jan (referee)
Type 1 Diabetes (T1D) is organ-specific autoimmune disease which causes pancreatic beta cells to be irreversibly destroyed. The only possible treatment represents life-lasting insulin administration. The real trigger of destructive insulitis isn't known. T1D is a multi- factorial disease involving both external and internal factors in the disease pathogenesis. The presence of autoreactive T lymphocytes in pancreas is necessary for development of diabetes. T regulatory cells have protective function in the destructive insulitis. The aim of this diploma thesis was to study cord blood T regulatory cells and their connection to type 1 diabetes development. We tried to find the difference among T regulatory cells in mononuclear cord blood cells (CBMC) in different study groups. Samples were collected from mothers suffering from T1D, gestational diabetes. Healthy controls were tested as well. Sixty-eight samples of cord blood were included in the study among the years 2009 - 2011. Samples were divided into 3 groups (CBMC from children born to T1D mothers, mothers with gestational diabetes and healthy mothers without T1D). CBMC were ana- lysed by flow cytometry. T regulatory cells (defined as CD4+CD25+) were isolated by magnetic separation (MACS). The functional capacity of these cells was studied as well by...
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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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Th17 lymphocytes and autoimmunity diseases with the intention of diabetes 1. type
Labiková, Jana ; Štechová, Kateřina (advisor) ; Procházková, Jana (referee)
Th17 cells were recently identified as a cell source of IL-17. They turned up to be a T cell lineage independent of previously described Th1 and Th2. The differentiation of naive CD4+ T cells towards Th17 requires the combination of TGFβ (a cytokine essential for the development of anti-inflammatory regulatory T cells) plus IL-6 or IL-21. IL-23 is required for in vivo function and phenotype maintenance of Th17. STAT3 and RORγt were identified as pivotal transcription factors in Th17 differentiation program. Th17 proved to have pro- inflammatory effects and are characterized by the production of IL-17A, IL-17F and IL-22 - cytokines implicated in host defense against certain extracellular pathogens. The cytokine products of Th17 cells act on wide range of cell types. They induce cytokines, chemokines and metalloproteinases and they also mediate neutrophil recruitment and production of antimicrobial peptides. Autoreactive Th17 are highly pathogenic and the production of IL-17 has been detected in several autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, psoriasis, Crohn's disease and type 1 diabetes. These diseases were thought to be mediated by Th1 cells, but it is becoming increasingly clear that the regulation of autoimmunity is influenced at least in some diseases by Th17 cells as well.
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Epigenetic regulation of HLA class II genes and their role in autoimmune diseases
Čepek, Pavel ; Černá, Marie (advisor) ; Štechová, Kateřina (referee) ; Reiniš, Milan (referee)
(EN) Type 1 diabetes (T1D) belongs among polygenic multifactorial autoimmune diseases. The highest risk is associated with HLA (human leukocyte antigen) class II genes, including HLA-DQA1 gene. Our aim was to investigate DNA methylation of HLA-DQA1 promoter alleles (QAP) and correlate methylation status with individual HLA-DQA1 allele expression of T1D patients and healthy controls. DNA methylation is one of the epigenetic modifications, that regulate gene expression and is known to be shaped by the environment. 61 T1D patients and 39 healthy controls were involved in this study. Isolated DNA was treated with sodium bisulfite and HLA-DQA1 promoter sequence was amplified using nested PCR. After sequencing, DNA methylation of HLA-DQA1 promoter alleles was analyzed. Individual mRNA HLA-DQA1 relative allele expression was assessed using two different endogenous controls (PPIA, DRA). We have found statistically significant differences in HLA-DQA1 allele 02:01 expression (PPIA normalization, Pcorr=0.041; DRA normalization, Pcorr=0.052) between healthy controls and T1D patients. The complete methylation profile of the HLA-DQA1 promoter was gained with the most methylated allele DQA1*02:01 and the least methylated DQA1*05:01 in both studied groups. Methylation profile observed in T1D patients and healthy...
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The incidence of specific islet cell autoantibodies in patients with HNF1A-MODY and HNF4A-MODY
Urbanová, Jana ; Anděl, Michal (advisor) ; Štechová, Kateřina (referee) ; Bém, Robert (referee)
Islet cell autoantibodies are associated with autoimmune insulitis and belong to the diagnostic criteria of Type 1 diabetes mellitus. However, growing evidence suggests that autoantibodies are present in other types of diabetes. Here, we focus on the autoantibody incidence in Czech patients with maturity-onset diabetes of the young (MODY) and analyze their functional relevance in terms of diabetes onset and control. Autoantibodies against glutamic acid decarboxylase 65 (GADA) and protein tyrosine phosphatase islet antigen 2 (IA-2A) were measured in a cohort of 28 Czech patients with MODY (all confirmed by genetic testing). Selected clinical data were correlated to the status and kinetics of autoantibodies. One quarter of patients with MODY examined (7/28; 25%) was positive for GADA or IA-2A. GADA were more prevalent (7/7) than IA-2A (1/7). The incidence of autoantibodies did not correlate with human leukocyte antigen status, nor with particular mutation in MODY genes. The patients who were positive for the autoantibodies developed diabetes later than those who were autoantibody- negative, but had worse glycaemic control. Expression of autoantibodies decreased with any improvement of diabetes compensation. Only one patient did not correspond to the above and displayed signs of combined signs of MODY...
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Immunointerventional therapy of autoimmune diabetes with recent oncet in NOD mice.
Vargová, Lenka ; Saudek, František (advisor) ; Štechová, Kateřina (referee) ; Mráz, Miloš (referee)
Introduction: Type 1 diabetes mellitus is a chronic metabolic disease caused by autoimmune destruction of pancreatic beta cells. The theory of the disease onset is derived from study of a disease course in non-obese diabetic (NOD) mice, in which the diabetes occurs due to a dysregulation of the immune system. Experimental and clinical studies showed that the autoimmunity may be abrogated by immune intervention, which if initiated early enough may at least slow down the ongoing beta cells lost and preserve residual insulin secretion. But immune intervention alone is not sufficient to restore normoglycemia in the majority of cases. Several interventional studies showed that stimulation of proliferation and/or regeneration of beta cells are necessary to restore normoglycemia in animal models. Aim of the study: To find out, if the combination of a potent immunosuppression (murine anti-thymocyte globulin (mATG), gusperimus) together with stimulation of islet regeneration (sitagliptin) will be able to slow down or reverse the course of the disease. Another aim is to identify the mechanism by which the substances act. Material and methods: All experiments were performed in female NODShiLtJ (H2g7 ) mice. The following parameters were examined at day 0, 7, 14 and 28: blood glucose, subpopulations of...
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