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Roles of antigen presenting cells in regulation of Th17 response against Candida albicans
Böhmová, Helena ; Dobeš, Jan (advisor) ; Kostovčíková, Klára (referee)
Candida albicans is a common human pathobiont that inhabits mucosal surfaces throughout the body. In healthy individuals, it behaves as a benign member of the microfora. However, in immunocompromised individuals Candida becomes pathogenic and causes extensive mucosal infections. In the most severe cases, Candida translocates into the bloodstream and causes life-threatening deep tissue infections. Although the innate immune components involved in early anti-Candida immune response are relatively well defned, our knowledge regarding adaptive T cell responses to Candida is limited. Several populations of antigen-presenting cells (APCs) have been implicated in the induction of protective Th17 response against Candida - including innate lymphoid cells type 3 (ILC3s), conventional dendritic cells (cDCs) and CX3CR1+ mononuclear phagocytes (MNPs). The cellular and molecular mechanisms by which Candida-specifc T cells are induced have not yet completely been identifed. Presented thesis focuses on the involvement of direct antigen presentation by these APC populations in mounting the anti-Candida adaptive immune response. Furthermore, this is investigated in the context of both gastrointestinal colonization and bloodstream infection by C. albicans. In the frst part, published data concerning the immune...
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Monogenic susceptibility to infectious pathogens
Bloomfield, Markéta ; Šedivá, Anna (advisor) ; Koziar Vašáková, Martina (referee) ; Litzman, Jiří (referee)
(ENG) The modern approach to studies of monogenic inborn errors of immunity, driven by unprecedented advances of genetic tools, opens vast undiscovered areas of immune system components and functions. In particular, the diseases with striking clinical phenotypes with normal or near normal baseline immunophenotype, such as disorders of innate and intrinsic immunity with susceptibility to single pathogen, provide a unique window into the host-pathogen interactions. This thesis covers various novel aspects of immunopathology, genetics and clinical facets behind some such diseases, namely chronic mucocutaneous candidiasis due to hypermorphic (gain-of-function, GOF) STAT1 mutations, which hamper Th17-associated immune activities, and Mendelian susceptibility to mycobacterial diseases (MSMD) due to impairment of IL-12, IL-23/IFNγ signalling pathway. Moreover, it contributes to the mounting evidence that IL- 6 signalling is non-redundant in anti-staphylococcal immunity. Finally, it explores the novel Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS- TS) as a single pathogen-driven life-threatening immunopathology, which most likely develops due to individual, yet unknown, genetic predisposition. The findings presented in this thesis were in several cases translated...
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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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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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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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Th17 lymphocytes and autoimmunity diseases with the intention of diabetes 1. type
Labiková, Jana ; Procházková, Jana (referee) ; Štechová, Kateřina (advisor)
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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