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Mechanisms of antigen presentation in the etiopathogenesis of celiac disease
Hudec, Michael ; Černá, Marie (advisor) ; Hrdý, Jiří (referee) ; Slavčev, Antonij (referee)
1 ABSTRACT Celiac disease (CeD) is a chronic autoimmune disease that develops as a response of the immune system to the presence of gluten in the small intestine. CeD is manifested not only by classic intestinal symptoms: abdominal pain, constipation or diarrhea, as well as complex less common symptoms: anemia, osteoporosis, psychiatric disorders or menstrual cycle disorders. HLA risk alleles predisposing to origin of celiac disease are HLA-DQ2 (DQA1*05:01 / DQB1*02:01) and HLA-DQ8 (DQA1*03:01 / DQB1*03:02). There are other celiac disease-associated polymorphisms outside of HLA locus (6p21.3) that are located in 5q32 and 19p13 regions with unclear connection to CeD development. HLA class II glycoproteins are expressed on antigen presenting cells (APC) that include dendritic cells, macrophages and B cells. Monocytes are one of several possible dendritic cell precursors that circulate in the bloodstream. Deviations in the frequency of intermediate monocytes are directly associated with autoimmune disorders such as Crohn's disease or rheumatoid arthritis. It is known that the monocytes of CeD patients show pro-inflammatory reaction in the presence of gluten. It means that, in the context of CeD, the response to gluten arises earlier than the activation of gluten-specific T cells. The conventional way of direct...
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Identification of new regulators of proinflammatory signaling pathways
Dráberová, Helena ; Štěpánek, Ondřej (advisor) ; Krulová, Magdaléna (referee) ; Funda, David (referee)
Identification of new regulators of proinflammatory signaling pathways Helena Dráberová Protein 4.1R has been described in immune system as regulator of migration and cell adhesion, but was also shown to play a role in activation of T lymphocytes. Polymorphism in gene ORMDL-3 is associated with asthma risk in children and correlates with increased ORMDL-3 expression. This disertation thesis describes the function of proteins 4.1R and ORMDL-3 in activation of mast cells after stimulation of FcεRI receptor. IL-17 is a proinflammatory cytokine that plays a role in immune response against fungal and yeast infections. IL-17 however also plays a role in the pathology of autoimmune diseases such as reumatoid arthritis, psoriasis and multiple sclerosis. IL-17 signaling is tightly regulated, however the exact mechanism has not been described. This disertation thesis describes the IL-17R complex by mass spectrometry and analyze the function of its known and newly discovered components in cells deficient in individual proteins by method CRISPR-Cas9. Last part focuses on the discovery of new subunit of IL-17RC protein CMTM4, which role in IL-17 signaling has not been described so far. CMTM4 stabilizes IL-17RC and is required for its surface expression. In vitro data are supported by data from autoimmune model of...
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Targeting IRAK4 kinase in autoimmune diseases and cancer
Synáčková, Alžběta ; Dráber, Peter (advisor) ; Brdička, Tomáš (referee)
Immune system provides host protection against invading pathogens. However, aberrant activation can lead to development of autoimmune diseases or cancer. Understanding the mechanisms of inflammation and immune responses is crucial for treatment of such conditions and reestablishing immune balance. Toll-like receptors and interleukin-1 family receptors are a key component of the innate immune system. Their downstream molecules, MyD88 and IRAK4, are essential for receptor signaling as their deficiency causes host susceptibility to infection. On the other hand, overactivation of this pathway was shown to be able to promote autoimmunity and cancer. The main focus of this text will be to summarize current knowledge about the mechanism of IRAK4 signaling and how it can be exploited in the development of therapeutics. Keywords IRAK4, MyD88, Toll-like receptors, IL-1 receptor, cytokines, autoimmunity, cancer
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Evolutionary implications of innate immunity receptors polymorphism
Bainová, Zuzana ; Vinkler, Michal (advisor) ; Zajícová, Alena (referee)
Interactions between hosts and their parasites are considered to be one of the major forces driving animal evolution. It can be assumed that the evolutionary changes will occur especially in host molecules directly involved in these interactions. The first line of host defense is formed by innate immunity receptors among which also pattern recognition receptors (PRRs) belong. PRRs detect the presence of parasites at the beginning of their invasion by binding characteristic structures of their bodies (so called pathogen-associated molecular patterns, PAMPs, e. g. lipopolysaccharide, flagellin or peptidoglycans) or abnormal self molecules (damage-associated molecular patterns, DAMPs, e.g heat shock proteins). Although this mechanism of immune system activation is based on the recognition of ligands that are relatively evolutionarily conservative in pathogens, growing body of evidence suggests that PRRs are highly polymorphic on both interspecific and intraspecific level. High frequencies of minority alleles can be observed in most populations studied. It has been proven that particular alleles of many PRRs may associate with increased or decreased resistance to various infectious or autoimmunity diseases. Relationship between polymorphic receptor and a disease could be the main force, which shapes the...
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Autoantibodies against calreticulin in patients with dilated and hypertrophic cardiomyopathy
Sánchez, Daniel ; Tlaskalová - Hogenová, Helena (advisor) ; Javorková, Eliška (referee)
Distinct cellular level of the Ca2+ binding chaperone calreticulin (CRT) is essential for cardiac development and postnatal function. However, CRT is also a potential autoantigen eliciting formation of antibodies (Ab), whose role is not yet clarified. Immunization with CRT leads to cardiac injury, and overexpression of CRT in cardiomyocytes induces dilated cardiomyopathy (DCM) in experimental animals. Hence, we analysed levels of anti-CRT Ab and calreticulin in the sera of patients with idiopatic DCM and hypertrophic cardiomyopathy (HCM). ELISA and immunoblot using human recombinant CRT and Pepscan with synthetic, overlapping decapeptides of CRT were used to detect anti-CRT Ab. Significantly increased levels of anti-CRT Ab of IgA (P<0.001) and IgG (P<0.05) isotypes were found in patients with both DCM (12/34 seropositive for IgA, 7/34 for IgG) and HCM (13/38 seropositive for IgA, 11/38 for IgG) when compared with controls (2/79 for IgA, 1/79 for IgG). Titration analysis in seropositive DCM and HCM patients documented anti-CRT Ab detected at 1/1600 dilution for IgG and 1/800 for IgA (and IgA1) and at least at 1/200 dilution for IgA2, IgG1, IgG2 and IgG3. Pepscan identified several immunogenic CRT epitopes: EVKIDNSQVESGSLED, IDDPTDSKPE, DKAPEHIPDPDA and RKEEEEAEDKEDDAEDKDEDEEDE recognised by IgA and...
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Novel mechanisms of T cell-mediated intestinal autoimmunity to Paneth cells
Brabec, Tomáš ; Filipp, Dominik (advisor) ; Janečková, Lucie (referee)
(En) Paneth cells are one of the major player in the maintenance of the homeostatic relationship between intestinal microbiota and the immune system. This function is largely achieved by their production of bactericidal enteric α-defensins (ED) and other antimicrobials. Disruption of Paneth cell functions is associated with severe human disorders such as Crohn's disease (CD) and Autoimmune Polyendocrinopathy- Candidiasis-Ectodermal Dystrophy (APECED). However, there is only a very limited information regarding the interactions and regulatory circuits operating between Paneth cells and intestinal immune system in either health or under pathological conditions. The previous study conducted in our laboratory described a new mechanism for the initiation and maintenance of Paneth cells targeted autoimmunity. The suggested model was that ED-specific T cells escape the selection in the thymus, infiltrate the intestine and diminish Paneth cell numbers through autoimmune destruction. This process also lead to the accumulation of inflammation- inducing bacteria, which were implied to exacerbate the inflammatory autoimmunity. Since this model of intestinal autoimmunity is of correlative nature, its intrinsic mechanism and functional relationships between immune system, Paneth cells and microbiota are largely...
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Defensins and autoimmunity: emerging alpha-defensin based model to study mechanisms underpinning autoimmune processes
Neuwirth, Aleš ; Filipp, Dominik (advisor) ; Černý, Jan (referee) ; Michálek, Jaroslav (referee)
The process of immune "self-nonself discrimination" is of utmost importance for the survival of all species as the biodestructive force of immune system can be directed towards the host as much as to pathogens. Thus, to shift this balance towards the latter, T cells bearing self- recognizing receptors are removed in the thymus (central tolerance) or their reactivity is harnessed through various additional mechanisms in periphery (peripheral tolerance). If the selfreactive T cells are not deleted and persist in the body, the regulation of self-tolerance can be breached, leading to the onset of autoimmunity. Presented thesis revolved around α-defensins, very effective bactericidal peptides that represent an important part of humoral innate immunity. There are two types of α-defensins: myeloid, expressed predominantly in neutrophils, and enteric, synthesized by intestinal Paneth cells. Data presented inhere are first to characterized the involvement of α-defensin- expressing cells in two types of autoimmune diseases, insulin-dependent diabetes mellitus (T1D) and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). The former relates to the identification of transcriptionally activated myeloid α-defensin- expressing eosinophils present in the thymus of diabetes prone rat. In...
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Glaucoma - family-based genetic analysis in relation to autoimmunity
Buchtelová, Aneta ; Daňková, Pavlína (advisor) ; Ďuďáková, Ľubica (referee)
Introduction: Recent findings about the pathogenesis of glaucoma have already demonstrated the presence of some specific autoimmune mechanisms. It has also been shown that autoimmune diseases often manifest in co-occurrence, such as celiac disease and type 1 diabetes mellitus or psoriasis. This association can be explained by sharing some of the risk variants of HLA molecules class II. Considering glaucoma an autoimmune disease, the question raises how the glaucoma genetic risk factors affect the phenotype of another autoimmune disease or vice versa, whether genetic risk variants associated for example with celiac disease can affect the glaucoma phenotype. Aims: The aims of this study were to i) identify possible genetic risk markers associated with the development of glaucoma, based on the available literature, and to map their occurrence among members of a three-generation family suffering from glaucoma and multiple autoimmune diseases, ii) find carriers of HLA-DQ2/DQ8 among the members of the same family, iii) verify whether an individual's genotype correlates with his/her phenotype, and iv) determine the potential effect of specific HLA alleles on the glaucoma phenotype. Material and methods: This study used DNA samples derived from 34 members of a three-generation family, in which coeliac...
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Immunogenetic and hormonal markers of predisposition to systemic rheumatic diseases particularly systemic lupus erythematosus
Fojtíková, Markéta ; Pavelka, Karel (advisor) ; Hrnčíř, Zbyněk (referee) ; Rovenský, Jozef (referee)
Fojtikova 2011 INTRODUCTION: Several factors like genetic susceptibility is required for systemic rheumatic diseases development. Immunomodulatory PRL effect supports autoimmunity. AIMS: 1. To detect the immunogenetic background (alleles HLA class I, II and microsatellite polymorphism of the transmembrane part exon 5 of MIC-A gene) of SLE and PsA. 2. To detect PRL serum and synovial fluid with regard to clinical and laboratory RA activity. 3. To find the role of the functional polymorphism -1149G/T SNP PRL of extrapituitary promoter of PRL gene in SLE, RA, PsA, SSc and inflammatory myopathies development. METHODS: Genetic analyses of pateints with SLE (n=156), RA (n=173), PsA (n=100), SSc (n=75), PM (n=47) a DM (n=68) and 123 healthy individuals: PCR-SSP (HLA clase I and II), PCR-fragment analysis (MIC-A) a PCR-RFLP (-1149 G/T SNP PRL). In 29 RA a 26 OA PRL serum and synovial fluid concentrations were detected using immunoradiometric assay. RESULTS: 1. The allele HLA-DRB1*03 (pc=0.008; OR 2.5) and haplotype HLA-DRB1*03-DQB1*0201 (pc <0.001; OR 4.54) were determined as risk immunogenetic markers for SLE in Czech population. In SLE versus controls allele MIC-A5.1 was increased (pc =0.005; OR 1.88). MIC-A5.1 together with HLA-DRB1*03 increases the risk for SLE development, pc <0.000001; OR 9.71....
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