|
|
Immunomodulatory and differentiation properties of MSCs in a mouse model of the injured cornea and retina
Kössl, Jan ; Holáň, Vladimír (advisor) ; Vištejnová, Lucie (referee) ; Heissigerová, Jarmila (referee)
Stem cells, in general, represent the potential for treating many diseases and disorders that are currently difficult to treat or the therapy has many side effects. One of the stem cells widely investigated these days are mesenchymal stem cells (MSCs). MSCs have the considerable immunomodulatory and regenerative potential for treating degenerative disorders and severe damage to various parts of the eye or other organs. Likewise, their application could serve as supportive therapy in corneal transplantation and other eye inflammatory conditions. In this study of immunomodulatory properties of MSCs, we have focused mainly on their ability to differentiate into cells of different tissue types (in our case, corneal epithelium and retina), their production of immunomodulatory molecules in the inflammatory environment, their ability to migrate to the site of the injury, and their local anti-inflammatory, regenerative, and anti-apoptotic effects. In addition, we tested the therapeutic effects of MSCs in a mouse model of ocular surface injury and a model of retinal degeneration. Finally, we investigated the mechanism of this effect in in vitro models with explants of these tissues. Limbal stem cells (LSCs) are already used to treat severe corneal damage as limbal stem cell deficiency. However, this...
|
|
|
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...
|
|
| |
|
| |
|
|
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...
|
|
|
Regulatory roles of PAG and CSK in FcɛRI signaling of mast cells
Potůčková, Lucie ; Dráber, Petr (advisor) ; Šebo, Peter (referee) ; Holáň, Vladimír (referee)
8 1 ABSTRACT (EN) This thesis is focused mainly on understanding mechanisms of regulatory roles of C-terminal Src kinase (CSK) and phosphoprotein associated with glycosphingolipid- enriched microdomains (PAG) in the high-affinity IgE receptor (FcɛRI)-mediated signaling of murine mast cells. FcɛRI activation is initiated by aggregation of the receptor by complexes of multivalent antigen with IgE, followed by activation and enhanced activities of protein tyrosine kinases, phosphatases, adaptor proteins and number of other signal transduction molecules. The signaling events result in mast cell degranulation and release of variety of proinflammatory mediators, responsible for initiation of allergy and other inflammatory diseases. Understanding the function of key regulatory molecules controlling FcεRI-mediated mast cell activation, degranulation, and cytokines production could have therapeutic impact. CSK is a major negative regulator of Src family tyrosine kinases (SFKs) that play a critical role in various immunoreceptor signaling events. However, its function in mast cell activation has not been completely understood. Because of its cytoplasmic localization, CSK was assumed to be brought to the vicinity of the plasma membrane- bound SFKs via binding to membrane-bound adaptors and PAG was a major candidate....
|
|
| |
|
|
Interaction between NKT and myeloid derived suppressor cells and antitumour immunity
Straňavová, Lucia ; Reiniš, Milan (advisor) ; Holáň, Vladimír (referee)
Myeloid- derived suppressor cells (MDSCs) are a heterogeneous population of cells, which plays an important role in the suppression of anti-tumor immune responses. NKT cells represent an additional heterogeneous cell population that plays a crucial role in the regulation of immune responses. It shows that MDSCs and NKT cells may be similar to other populations imunoregulatory cells interact with each other and influence their functions. These interactions are important regulatory factor that may contribute to activation and to suppress anti-tumor immunity. Through interactions with type I NKT cells could differentiate these immunosuppressive MDSCs to immunogenic APC, which could form the basis for immunotherapeutic vaccine. All interactions between the NKT and MDSCs but have a positive effect of imunoregulatory. Interaction between MDSCs and CD4 + NKT cells II. type are immunosuppressive and may subsequently suppress the activity of cytotoxic T-lymphocyte (CTL). In some tumor models it was found that the immunosuppressive nature may also be interactions between MDSCs and type I NKT cells He had, however, alleviate the use of all-trans-retinol acid (ATRA), which induces differentiation of MDSCs.
|
|
|
Mesenchymal stem cells and the possibility of their transdifferentiation into insulin producing cells.
Dostálová, Veronika ; Holáň, Vladimír (advisor) ; Čečrdlová, Eva (referee)
Mesenchymal stem cells (MSCs) have been demonstrated in almost all tissues of the body. Their main source is bone marrow and adipose tissue. These cells are multipotent, e.g. they are capable of differentiating into a variety of cell types. They are able to migrate into damaged tissues. Their other relevant property is a specific suppression of imunity. In the body they serve as precursors for specialized cell types and they also participate in formation of specific tissue microenvironment. Their properties represent a great potential in a wide range of clinical therapies. Besides other possible applications they could be used in the therapy of diabetes mellitus type one. During this disease insulin producing -cells are destroyed. MSCs have been used in experimental in vitro and in vivo studies to differentiate into insulin producing cells. However these cells are not able to produce sufficient amounts of insulin to exclude the supportive administration of exogenous insulin. Therefore there is a need for further research in this field of possible therapy.
|
|
| |
guest ::
