|
|
Immunomodulatory properties of vitamin D3
Urbanová, Anna ; Stříž, Ilja (advisor) ; Zajícová, Alena (referee)
1 Abstract Vitamin D3 is important for keeping the right concetration of Ca2+ in plasma. Therefore it is essential for proper bone growth and development. Nevertheless, vitamin D3 has also a number of immunomodulating effects. Our thesis has been targeted on evaluation and comparison of vitamin D3 influence on expression of chosen surface markers (CD14, CD54, HLA-DR, CD16, CD36 and CD163) with THP-1 cells and monocytes gained from human peripheral blood. Other aims have been analysing the vitamin D3 influence on longevity of THP-1 cells and measuring the soluble CD14 and IL-8 production with THP-1 cells under the vitamin D3 influence. The cells have been stimulated with five different concentrations of vitamin D3 for the time 24, 48 and 72 hours. Higher used concetrations of vitamin D3, i.e. 100 nM and 1000 nM have increased the expression of CD14 with THP-1 cells in the time 48 and 72 hours of the stimulation time. With the monocytes from peripheral human blood the increase of the CD14 expression hasn't been remarkable from the physiological point of view. Together with the vitamin D3 concentration increase the sCD14 production with THP1 cells was considerably higher. The sCD14 was the highest in the time 72 hours after the stimulation with the highest used vitamin D3 concetration. The IL-8 quantity with...
|
|
|
Role cytokinů ve vývoji a diferenciaci regulačních T buněk
Procházková, Jana ; Holáň, Vladimír (advisor) ; Kovář, Marek (referee) ; Stříž, Ilja (referee)
The development and function of T helper (Th) cells and regulatory T cells (Tregs) are plastic processes that are regulated by cytokines. In our project we first analyzed the effect of different cytokines on the development of induced (i) Tregs. It has been demonstrated that iTregs arise from CD4+ CD25- T cells upon stimulation with alloantigen in the presence of transforming growth factor β (TGF-β). The development of these Tregs and their proliferation were inhibited by interleukin (IL)-4 and IL-12. The aquired results also demonstrated distinct responses of naturally occuring (n) Tregs and iTregs to the regulatory action of IL-4 and an opposite role of IL-4 in maintenance of nTregs and iTregs phenotype. An important role in the induction of T cell subsets may play also mesenchymal stem cells (MSCs) which can, under specific conditions, produce TGF-β and IL-6. Depending on the current production of TGF-β or IL-6, MSCs can qualitatively regulate the ration between Tregs and Th17 cells. Anti-inflammatory Tregs and pro-inflammatory Th17 cells are induced upon stimulation in the presence of TGF-β and TGF-β and IL-6, respectively. In addition to our previous work we studied the role of IL-12 in the development of Tregs and Th17 cells. It was shown that Treg and also Th17 cell differentiation was...
|
|
|
Clinical significance of cytokine gene polymorphism
Kolesár, Libor ; Stříž, Ilja (advisor) ; Holáň, Vladimír (referee) ; Mrázek, František (referee)
Univerzita Karlova v Praze Přírodovědecká fakulta Studijní program: Doktorský studijní program v biomedicíně Studijní obor: Imunologie Mgr. Libor Kolesár Klinický význam polymorfismu cytokinových genů Clinical significance of cytokine gene polymorphism Disertační práce Vedoucí závěrečné práce/Školitel: Prof. MUDr. Ilja Stříž, CSc Praha 2012 Abstract The human genome is full of different sequence variants. They are different mainly in size but also in their influence on phenotype. The smallest unit of genetic polymorphism is single nucleotide polymorphism (SNP). SNPs represent a single nucleotide change between two alleles and might affect the gene expression. We have studied SNPs in three distinct fields as: (1) marker of risky patients after the organ transplantation, (2) diagnostic marker of patients with interstitial lung diseases (ILD) or (3) with uterine fibroid (UF). We have come to the following results. Ethnicity or even nationality plays a role in the distribution of genetic polymorphism. This must be absolutely taken into account when one would like to transfer findings of a clinical study from a certain nation or ethnic and applied them to his studied group for the comparative purposes. Our first clinical gene-association study has found that even gene polymorphism of the IL-18 gene may...
|
|
|
Chemokines of epithelial cells in bronchial asthma
Volfová, Dominika ; Stříž, Ilja (advisor) ; Holáň, Vladimír (referee)
Asthma is an allergic disease caused by adverse reactions to harmless antigens (allergens) and is characterized by the recruitment of eosinophils, Th2 lymphocytes, mast cells and neutrophils into the tissue site of inflammation, to the lungs. This accumulation of leukocytes is mediated by the generation of chemotactic cytokines (chemokines). Chemokines are low molecular weight proteins, functioning by binding to specific receptors on the cell surface. Binding of chemokines and their receptors is highly promiscuous and subsequent activation of effector cells is very heterogeneous, which can often complicate research in this area. However, chemokines and their receptors are important potential therapeutic targets in allergic diseases including asthma, mainly because of their central role in cell activation and inflammation. Chemokines are secreted by cells of the immune system and cells of various tissues of the body. Recently, attention turns to the role of epithelial cells in the pathogenesis of asthma. Bronchial epithelial cells stimulated by antigens produce cytokines and defense molecules used for the amplification of inflammatory processes and regulate the aktivity of effector cells. Impaired cytokine regulation may lead to the development of various lung diseases including asthma. This work...
|
|
|
Regulation of the cytokine IL-33 production and its biological effects.
Kardošová, Miroslava ; Stříž, Ilja (advisor) ; Zajícová, Alena (referee)
IL-33 is a dual function protein that may function as both a proinflammatory cytokine and an intracellular nuclear factor. In a role of cytokine IL-33 signals via receptor ST2 and induces T helper type 2-associated cytokines in its target cells including mast cells, basophils, eosinophils and natural killer cells. Additionally, it acts as chromatin-associated nuclear factor with transcriptional regulator properties affecting expression of some proinflammatory cytokines. Regulation of this processes is poorly understood, mechanisms underlying synthesis, processing and secretion of IL-33 also remain to be fully explored. The aim of our study was to examine mechanisms probably involved in regulation of IL-33 production and its secretion outside the cell. First, we investigated possibility that IL-33 secretion is affected by stimulation with cytokines TNFα, IFN γ, IL-1β, IL-13, IL-33, TGF-β and IL-10 or stimulation with LPS isolated from E. coli. Next we investigated hypothesis that IL-33 is released from cells during cell damage or necrosis and serve as "alarmin". Necrosis was induced in LPS-stimulated cells by freeze-thawing cycles. Besides the presence of IL-33 we tested levels of IL-1α and IL-1β. In our experimental model, we used A549 cell line (alveolar type II-like cells), THP-1 promonocytic...
|
|
|
Immunomodulatory effects of macrolide antibiotics
Zemánková, Jana ; Stříž, Ilja (advisor) ; Krulová, Magdaléna (referee)
Macrolide antibiotics are well known not only for their antibacterial properties, but also for their recently discovered anti-inflammatory properties. They are able to significantly suppress destructive and in many cases life-threatening inflammation, an effect which is desired especially in chronic inflammatory diseases. The principle which their act is the modulation of the various components of the immune system. These effects are called "immunomodulatory" and can also include the effect on epithelial cells and their secretory activity, as well as the effect on pathogens which can colonize the airways and contibute to pathogenesis and the emergence of the chronic inflammatory respiratory diseases. This thesis summarizes the most important known mechanisms, by which macrolide antibiotics exert these immunomodulatory effects, and also notes examples of diseases whose treatment is the most clinically significant. Macrolide antibiotics posessing these uniqe anti-inflammatory properties are well tolerated and severe side-effects are rare. However, the most serious risk is the emergence of resistance and that is the main reason why this treatment can not be recommended without reservation. It is up to each doctor to consider the risks and benefits of the treatment in each individual patient.
|
|
|
Cytokines in the effector function of regulatory T cells
Zadražil, Zdeněk ; Holáň, Vladimír (advisor) ; Stříž, Ilja (referee)
Regulatory T cells (Treg) are an important control mechanism within the Immune system (IS). Tregs prevent overactivation of effector T cells or autoreactive cells from invading organism-derived tissues. Treg are characterised by expression of surface molecules, CD4, CD25 and by an intracellular transcription factor forkhead box protein 3 (FoxP3). There are two basic populations of Treg, naturally occuring Treg (nTreg) developing in the thymus and induced Treg (iTreg) rising from CD4+ T cells in periphery, which are also precursors for T helper cells. In spite of an outgoing intensive research, there is still no clear clue which mechanisms are used by Treg to inhibit other effector cells. First in vitro experiments showed, that those mechanisms are of a contact dependent manner and do not use secreted molecules. But in vivo experiments showed the exact opposite. Those studies showed that secretory molecules, such as interleukin (IL)-10, IL-35 or transforming growth factor beta (TGF-β), are important in the effectory phase of Treg. Since the first experiments other distinct mechanisms of supression by Treg cells have been discovered. Those mechanisms seem to be important only in particular situations, particular cell assays or with using of specific experimental models. The reasons for this...
|
|
|
The role of T regulatory cells in kidney transplantation
Urbanová, Anna ; Stříž, Ilja (advisor) ; Zajícová, Alena (referee)
T regulatory lymphocytes (Treg) belong to the CD4+ cell group. They are an essential part of the immunity system. Treg cells prevent from excessive activation of effector T cells and they keep the tolerance to the tissues of the body. They have high expression of CD25 and the transcription factor Foxp3. We distinguish two basic populations of Treg cells: natural Treg cells (nTreg) created in the thym and representing 5-10 % of all CD4+ cells, and induced Treg cells (iTreg), created from naive CD4+ cells in the periphery.Their regulatory effect is well-known, therefore using of Treg cells could bring about a huge treatment potential for patients with a transplantated kidney. Healthy people and patients tolerant to the transplantated kidney show higher occurance of circulating Treg cells and the Treg cells present in the graft unlike patients with chronical rejection. The tolerance is cancelled with the damage of CD4+ CD25+ cells.For a graft acceptance it is necessary to treat the patient after the transplantation with immunosuppressive medicaments resulting in suppression of immunity reaction against the graft. Their disadvantages are side effects often resulting in the patient's death. Moreover they often have a negative impact on survival and expansion of Treg cells. The analysis of flow cytometry has...
|
|
|
Bacterial components in experimental intestinal inflammation prevention and therapy
Kverka, Miloslav ; Tlaskalová - Hogenová, Helena (advisor) ; Šedivá, Anna (referee) ; Stříž, Ilja (referee)
Although strong protective immune response is essential for preventing invasion by pathogens, equivalent responses against antigens originating from commensal bacteria can lead to chronic inflammatory diseases, such as inflammatory bowel disease (IBD). Manipulating the mucosal immune responses with microbial antigens might be an excellent tool to IBD therapy or prevention. Our aim was to gain some insight into the regulation of the intestinal inflammation and to isolate bacterial immunomodulatory components that could be used in intestinal inflammation therapy and prevention. One particular mechanism of how healthy colon tissue regulates the inflammation during acute experimental colitis is through modulation of bioavailability of glucocorticoids (GCs) in gut mucosa. Here, we show that intestinal inflammation changes the local GC metabolism, which ultimately leads to decrease in inflammatory readiness of cells in the gut mucosa and in mesenteric lymph nodes. This pre-receptor regulation of GC function could represent an important homeostatic function of the gut mucosa. The actual triggers of intestinal inflammation in IBD seem to be either microbial dysbiosis or microbes with special "pathogenic" abilities, which both could be rectified by feeding with probiotics. Here, we report that oral feeding with live...
|
|
|
The role of macrophages in immunosuppression mediated ny regulatory T cells
Kadlecová, Kristýna ; Holáň, Vladimír (advisor) ; Stříž, Ilja (referee)
Regulatory T cells (Treg) represent one of the most important mechanisms of immunoregulation. Treg suppress immune reactions and prevent overactivation of the immune system. There is a lot of ways of Treg action described, here we have focused on Treg interference with macrophages. The suppressor capacity of a highly purified Treg population was demonstrated in proliferation assays. The level of suppression of effector T cell proliferation differs depending on the presence of macrophages in the culture. Treg suppression has been significantly higher in the presence of macrophages. These observations led to hypotesis that Treg affect directly macrophages. However, using flow cytometry, reduction of expression of costimulatory molecules on macrophages after culture with Treg was not observed. Macrophages precultured with Treg showed a comparable functionality as macrophages cultured alone. Neither flow cytometry nor live cell imaging revealed any cytotoxic activity of Treg towards macrophages. Despite the presence of macrophages, Treg did not suppress effector cell proliferation in a model, where stronger activation of effector cells was induced. Therefore, a new hypothesis was presented - initially observed higher suppression in the presence of macrophages was probably caused by a qualitatively or...
|
guest ::
