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Immunoscore in 3D tissue
Novák, Jaromír ; Drbal, Karel (advisor) ; Procházka, Jan (referee)
Solid tumors are complex structures comprising besides the cancer cells vasculature, extracellular matrix (ECM), soluble molecules and a plethora of various other cell types. These components form a so-called tumour microenvironment. From the numerous cell types that are part of tumor microenvironment, tumor infiltrating lymphocytes (TILs) play a major role in patient prognosis. Their presence is also of major importance with regard to new biological therapies based on immune checkpoint inhibitors. Crucial role of TILs is also reflected by the new approaches in cancer diagnostics namely by Immunoscore method (currently used in clinical settings). Immunoscore is based on localization and quantification of CD3+ and CD8+ TILs in thin histological sections of tumor tissue. The question remains to which extent the information obtained from 2D slices reflects the situation in tumor microenvironment considering its spatial heterogeneity. The development of new methodological approaches allowing evaluation of histological information in 3D is the key to answer this question. The theoretical part of this work first describes the heterogeneity of the tumor microenvironment and the role of immune cells within it. Then, the role of spatial heterogeneity and its possible influence on the histopathological...
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Leukaemia associated immunophenotype in childhood acute leukaemias and its development during the course of disease
Podolská, Tereza ; Fišer, Karel (advisor) ; Drbal, Karel (referee)
Acute lymphoblastic leukaemia (ALL) is the most frequent childhood malignancy. One of the recent improvements in ALL treatment was the introduction of minimal residual disease (MRD) monitoring that enables risk stratification based treatment adaptation. The same MRD monitoring helps to choose relapse treatment, to guide indication for stem cell transplantation (SCT) and allows for a more personalized management of patients undergoing SCT. One of the main routes of MRD levels detection is characterisation of leukemic blasts using flow cytometry. However, flow cytometry is limited by its mainly manual expertise-based analysis. Such analysis is subjective and clearly insufficient for current complex data. While new computational tools are available for multidimensional flow cytometry data, there is an urgent need to test and adapt them for the use in clinical environment. The goal of this thesis is to detect immunophenotypes associated with leukaemia and their development by leveraging machine-assisted analysis of a set of diagnostic files selected based on information about more than three hundred thousand of multiparameter flow cytometry datasets. Advanced bioinformatic tools will help to detect blast and healthy haematopoietic populations, to derive their immunophenotypes and to identify individual...
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Hematopoiesis in the models of zebrafish and medaka as a recipient for human HSC xenograft
Pravcová, Naďa ; Drbal, Karel (advisor) ; Svoboda, Ondřej (referee)
Danio rerio (zebrafish) and Oryzias latipes (medaka) have recently become popular model organisms to study hematopoiesis. These model organisms present several advantages in comparison to other commonly used models, the most common being Mus musculus (mouse). The advantages are shorter generation time, large offspring production, frequent spawning, external fertilization and development, the optical transparency of embryos amenable to genetic manipulation on the background of vast numbers of transgenic lines (mainly in zebrafish) and inbred strains (in medaka). Moreover, most of the mechanisms behind zebrafish and medaka hematopoiesis are conserved in higher vertebrates. Most importantly, the optical transparency in early development and in adult mutant transparent strains allows for observation of hematopoietic stem cell (HSC) development in vivo. Therefore, it is possible to generate humanized fish using xenotransplanted human HSCs for studies of the engraftment, differentiation, and trafficking of human HSC in vivo. Currently, the most popular organism for human HSC xenotransplantation is mice. This model system is not suitable for in vivo imaging of HSC engraftment. Moreover, a prior immunodepletion step is necessary. The process of immunodepletion includes genetic manipulation or irradiation...
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Comparative structural analysis of Borreliella spp. virulent factors focusing on their surface topology conservation
Zdrha, Alois ; Drbal, Karel (advisor) ; Nunvář, Jaroslav (referee)
Gram-negative bacteria of genus Borreliella cause the nowadays spreading illness Lyme borreliosis. However, their classification as gram-negative bacteria is rather mislea- ding because they differ in their complex genome, pathogenic adaptation to their hosts and composition of their outer membrane. One species of borreliella can harbour up to 23 variable plasmids and one conserved chromosome and they still lack many crucial proteins needed for synthesis of key compounds. Hence, they have to obtain these compounds from the host. However, in order for borreliella to utilise the metabolic processes of the host, it has to first survive its immune response. Therefore borreliella contains many virulent factors including highly variable surface lipoproteins. The variability is a major obstacle to overcome when using their surface epitopes for detection and vaccine development because most of the dominant antigenic epitopes of borreliella are usually parts of the most variable regions of the lipoproteins. Nowadays, we can use many different algorithms which determine evolutionary conserved epitopes based on analysis of sequences of given lipoprotein, in order to find suitable targets for antibodies. In general, conserved epitopes are more suitable for vaccines, whereas more variable epitopes are better...
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Characterization of T-cell clones from naïve and virtual memory compartment
Přibíková, Michaela ; Štěpánek, Ondřej (advisor) ; Drbal, Karel (referee)
Virtual memory (VM) CD8+ T cells represent a population of antigen-inexperienced T cells with an apparent memory phenotype. In lymphoreplete germ-free mice VM CD8+ T cells represent 10-20% of all peripheral CD8+ T cells. Their origin correlates with the levels of self-reactivity where the main factor that determinates the T-cell fate decision is the strength of homeostatic signals. In the first part of this thesis, we demonstrated that VM CD8+ T cells and naïve CD8+ T cells had distinct TCR repertoire and T-cell subsets contained different clonotypes. Moreover, 'VM clones' were enriched among VM T cells and were also present in naïve T cells. In contrast, 'naïve clones' were almost exclusively detected in naïve T cells. Next, we characterized the signaling of particular OVA-reactive TCRs from both naïve and VM subsets. We confirmed that 6 out of 8 tested TCRs were responsive to Kb-OVA. In the last part of the thesis, we developed and optimized a qPCR-based method for the relative quantification of specific T-cell clonotypes prior to and during the immune response. This method will serve as a tool for studying the biology of particular VM and naïve T-cell subsets and their role during the immune response. Keywords: T-cell receptor, homeostatic signaling, self-reactivity, virtual memory cells, T cells
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Fibroblast activation protein and local immunosuppression in glioblastoma
Ternerová, Nikola ; Stollinová Šromová, Lucie (advisor) ; Drbal, Karel (referee)
Glioblastoma multiforme (GBM) is the most aggressive type of primary brain tumor. Current treatment includes surgical resection with following radio/chemotherapy, but prognosis of patients remains poor with median survival only about 15 months. GBM is characteristic for necrotic regions, abnormal vascularization and strong immunosuppression. Dynamic interactions of cancer cells, immune cells and other stromal cells in the tumor microenvironment can promote tumor growth and progression. Fibroblast activation protein α (FAP) is overexpressed by the cells in tumor tissue. FAP is important in angiogenesis, remodelation of extracellular matrix and immunomodulation in cancers. The role of FAP in the tumor microenvironment is the subject of recent research. The aim of the thesis was to prepare a syngeneic mouse model of glioblastoma with and without FAP expression, implement and optimalize the dissociation method for GBM tumor tissue and detect a variety of infiltrated immune cell populations in the GBM microenvironment by flow cytometry. Optimization of dissociation protocol for glioblastoma tissue was a crucial step for viable cell suspension required for cytometry study of immune cell populations. A combination of dissection by dissociator and enzymatic digestion with mild enzymes was found to be the...
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Genomic instability in patient tumors due to excesive AID activity
Vaníčková, Karolína ; Drbal, Karel (advisor) ; Macůrek, Libor (referee)
AID is a member of APOBEC family of mutational enzymes. AID generates U:G mismatches in ssDNA by deaminating cytosine to uracil. In B cells error-prone repair of these mismatches induces a mutational burden in the process of somatic hypermutation of Ig locus during affinity maturation of immunoglobulins (Ig). AID also induces double-strand breaks during Ig class switch recombination or primary Ig diversification through templated gene conversion in some vertebrate species. AID might gain tumorigenic potential in case of insufficient regulation of induction and repair processes, causing genomic instability and possibly leading to tumorigenesis. AID is induced in epithelial tissues by proinflammatory cytokines via canonical NF-B pathway. Both exogenous factors (pathogens Helicobacter pylori or HCV), endogenous factors (bile acid) or even physiological state such as ovulation are the initiating factors. Thus, AID might be the link between inflammation and carcinogenesis. AID is expressed in different stages of carcinomas, mostly during the initial oncogenic transformation. Mice with ectopic AID expression develop lung, gastric, oral and hepatic carcinomas as well as melanomas. AID also regulates epithelial-mesenchymal transition in other tumors. AID is responsible for treatment resistance in both CML...
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Tumor in vitro chemosensitivity and resistance assays (CSRA) using flow cytometry
Drozdová, Tereza ; Drbal, Karel (advisor) ; Balounová, Jana (referee)
In vitro chemosensitivity and resistance assay determine the sensitivity of a specific tumor after a specific treatment administration in an experimental setup. A heterogeneous population of cancer cells is exposed to various approved anticancer drugs in short-term ex vivo and their combination thereof. The effect of each drug is then determined based on the viability of specific tumor cells allowing for individual patient treatment using a precise combination of drugs. This approach is an example of the personalized medicine principle, which is focusing on the adjustment of diagnostic procedures and treatment of a specific patient. Therefore, its goal is to avoid treatment failure in patients with poor response to the statistically most effective treatments based on randomized clinical trials. The number of viable cells determined by the flow cytometry provides very accurate statistics for multiparametric analysis. A necessary prerequisite is the presence of dissociated cancer cells in a single cell suspension. This is different from cloning methods, where tumor colonies grow on agar media, or from histocultures, which are specific with its three-dimensional tissue cultivation. We can also sort cells from suspension based on their pre-defined attributes for their subsequent functional testing. The...
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Effects of the Interferon regulatory factor 3 on immune responses to vaccinia virus in the atopic organism
Pilná, Hana ; Mělková, Zora (advisor) ; Drbal, Karel (referee)
Vaccinia virus (VACV) is an enveloped DNA virus, member of the Orthopoxviridae genus. VACV genome size is about 200 kbp. This huge genome capacity allows VACV to encode a set of factors that are non-essential for virus replication and spread in vitro. While these factors are needed for interfering with host immune responses, VACV remains strongly immunogenic. Cell-mediated and humoral immune responses in atopic disorders are deregulated to a certain extent, leading to complications in case of infection or vaccination with vaccines based on replicating viruses, such as eczema vaccinatum caused by VACV. VACV effects on immune responses consist among others in the inhibition of expression of type I interferon (IFN) at various levels - for example in a specific inhibition of phosphorylation of the interferon regulatory factor-3 (IRF-3) via inhibition of the activity of TANK-binding kinase 1 (TBK 1) that normally phosphorylates IRF-3. Phosphorylation allows IRF-3 to translocate into the nucleus where it initiates transcription of IFNβ followed by induction of expression of IFN and interferon stimulated genes. Expression of these genes is shut down when IRF-3 activity is inhibited. To overcome this block, a recombinant VACV expressing murine IRF-3 under VACV p7.5 promotor (WR-IRF3) was generated....
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Cytometric assay of antigen-specific T cell response in monitoring of BCG vaccine therapy
Hadlová, Petra ; Drbal, Karel (advisor) ; Kalina, Tomáš (referee)
Bladder carcinoma (BCa) is among the most common carcinomas in the Western world. Despite the availability of effective therapies, there is currently an urgent need to develop a stratification method, which would enable the accurate identification of patients responsive to therapy. In the theoretical part of my diploma project I describe the heterogeneity of BCa and the currently applied immunotherapeutic approaches. I specifically focused on the Bacillus Calmette-Guérin (BCG) vaccine instillation. For decades another use of BCG has been a prophylactic vaccination against tuberculosis (TB) infection. BCG serves as a model treatment because it is highly efficient when prescribed to the responsive patient. However, an effective stratification is yet to be developed for BCa and latent tuberculosis infection (LTBI) diagnosis and/or monitoring. In the experimental part of my project, I developed and tested a 10-parameter panel for T cell- specific activation test (TAT) applicable for a stratification of BCa patients as well as for the detection of LTBI. I tested the panel on positive controls using flow cytometry (FCM) method because it allows for detection and measurement of dozens of markers at a single cell level. It is easily applicable to available urine and blood samples obtained from BCa...
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