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Combined immunotherapy of tumors with different expression of MHC class I molecules
Piataková, Adrianna Julia ; Šmahel, Michal (advisor) ; Krulová, Magdaléna (referee) ; Reiniš, Milan (referee)
Immunotherapy experienced ups and downs before being recognized as a paramount therapy for cancer. Evidence from the latest studies revealed that the tumour microenvironment (TME) plays a decisive role in the outcome of immunotherapeutic treatment. In addition, one of the mechanisms used by cancer cells to evade immunosurveillance is reduction of the expression of major histocompatibility complex class I (MHC-I), by which cancer cells become invisible to cytotoxic T lymphocytes (CTLs). Therefore, cancer immunotherapy should involve combined strategies to target both tumour cells and TME from different sites by activating other immune cells in addition to CTLs, such as tumour-associated macrophages (TAMs). This Ph.D. thesis aimed to investigate combined immunotherapy, composed of DNA immunization, immunostimulatory compounds, and an immune checkpoint inhibitor to activate adaptive and innate immunity and inhibit immunosuppression, respectively. For this purpose, murine models related to HPV-16-induced tumours with either reversibly (TC-1/A9 cell line) or irreversibly (TC-1/dB2m) reduced MHC-I expression were used. The development of the TC-1/dB2m clone was a part of this project and this clone was obtained by deactivating the B2m gene. An important focus of the research was the analysis of TAMs isolated from...
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Vliv chemoterapie a genotoxického stresu na imunologické vlastnosti nádorových buněk.
Horňáková, Michaela ; Reiniš, Milan (advisor) ; Drbal, Karel (referee)
Cancer treatment includes the use of chemotherapeutic agents, which have various effects on tumour cells, such as direct toxicity to cancer cells, immunogenic cell death induction and changes in cancer cells phenotype. Throughout the last decade many researchers have been focusing on the induction of genotoxic stress and cellular senescence, which chemotherapy can trigger. Even though induction of senescence in cancer cells represents an important mechanism for tumour suppression, there has been increasing evidence that shifting cancer cells into a senescent state by chemotherapy is not always beneficial. Senescent cells are associated with a specific secretory phenotype, which allows such cells to alter their microenvironment, modulate anti-tumour immunity, induce tumour suppression and even promote cancer development. Therefore, senescent cells elimination by innate or specific immunity, which can be boosted by immunotherapy, can be an important barrier preventing tumour growth. Powered by TCPDF (www.tcpdf.org)
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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.
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Induction of the immune response against HPV16-associated tumours with experimental vaccines
Kalenská, Romana ; Reiniš, Milan (advisor) ; Krulová, Magdaléna (referee)
5 Induction of the immune response against HPV16-associated tumours with experimental vaccines The E6/E7 oncoproteins of human papillomaviruses are expressed in most trans- formed cells of cervical carcinoma and, therefore, are attractive targets for T cell-mediated immunotherapy. We have investigated the capacity of vaccines based on E7 oncoprotein- derived peptides to induce cellular immune responses and their therapeutic potential for treatment of minimal residual disease after surgery in a murine experimental model mi- micking human HPV16-associated carcinomas. We compared the effect of E749-57 peptide (RAHYNIVTF) exhibiting immunodominant epitope recognized by cytotoxic T lymphocy- tes with E744-62 peptide (QAEPDRAHYNIVTFCCKCD = 8Q) exhibiting CTL, TH and B- cell epitopes. Immune responses were compared in healthy mice and in mice after surgery or chemotherapy of tumours with ifosfamide derivative CBM-4A. Cellular immune re- sponses were monitored in spleen cells of C57BL/6 mice using ELISPOT-IFN-γ and 51 Cr- release assay. Flow cytometry was used for the detection of CD4+ , CD8+ , CD4+ CD25+ , Gr-1+ CD11b+ and CD3+ NK1.1+ populations. Vaccination with 8Q peptide and synthetic CpG oligodeoxynucleotide as adjuvant induced stronger antitumour immune responses than immunodominant CTL epitope alone in both...
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Regulation of the expression of MHC class I molecules and other immunoactive molecules on tumor cells
Moravcová, Simona ; Reiniš, Milan (advisor) ; Vopálenský, Václav (referee)
4 Abstract Regulation of the expression of MHC class I molecules and other immunoactive molecules on tumor cells The aim of this master thesis project was to characterize the effects of IFNγ, TNFα and of the epigenetic agents 5-azacytidine (5AC) and 5-aza-2'-deoxycytidine (5AZAD) on the expression of molecules important for antigen presentation and modulation of the immune responses against tumors (MHC class I molecules and other immunoactive molecules CD54, CD80, B7-H1, B7-H2 and CD1d) on tumor cells. The experimental model used for this purpose were the HPV16-associated murine tumor cell lines, either MHC class I positive or negative. The goal was to determine the changes in surface expression of these molecules after treatment by FACS studies and also the expression at the mRNA level using qPCR. Expression of these proteins was also compared in the experiments in vitro on tumor cell lines and ex vivo on tumor cells explanted from animals. The most interesting result is the observation that 5AZAD increases the expression of B7-H1 which inhibits T cell mediated immune response and that 5AZAD and IFNγ act synergistically in the induction of the expression of MHC class I, CD54 and B7-H1 molecules. Klíčová slova: imunoeditace, protinádorová imunita, HVP16, MHC glykoproteiny I. třídy, B7-H1, IFNγ, TNFα,...
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Characterisation of the cell line TRAMP-C2 side population, mouse model of prostate cancer
Žlabová, Anna ; Reiniš, Milan (advisor) ; Šmahel, Michal (referee)
Side population is a minor subpopulation (SP) of some cell lines, exporting staining dye Hoechst 33342 out of their cytoplasm. It is discussed as a possible source of "cancer stem cells", "tumour initiating cells" or "metastasis initiating cells". However, broad literature suggest, that stemness and other privileged properties of SP are very variable between different cell types, cell lines and stage of disease. Cell lines TRAMP are the only widely available murine models for testing of prostate cancer therapy. We noticed in literature a mention about existence of 1-2% of cells constituting side population, but detailed characteristic have not been described until now. In this diploma thesis, we worked on characterisation of SP of the TRAMP-C2 cell line in comparison to other cells (nonSP). In the first part, we compared stem properties of SP and nonSP. We started with checking the existence of SP by its verapamil sensitivity. Using mRNA analysis, we showed that neither SP nor nonSP have increased c-Kit expression and that there are no differences in Bmi-1 expression. We found that SP is heterogenic mixture of CD24-CD44-, CD24-CD44+ and CD24+CD44+ cells, while nonSP is almost solely CD24-CD44+. We documented that SP and nonSP returned back to original SP ratio during cultivation. Then we showed on...
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Study of the effect of immunological sdjuvants on experimental treatment of HPV-induced tumors by recombinant VACV and DNA vaccines
Gabriel, Pavel ; Němečková, Šárka (advisor) ; Mělková, Zora (referee) ; Reiniš, Milan (referee)
1 ABSTRACT The success of cancer vaccines depends on factors associated with the vaccine, which define the main parameters of effective immune responses such as its size and quality, as well as on factors related with the host, represented by the immunosuppressive mechanisms that allow the tumor to escape recognition by the immune system or negatively influence the function of effector T-cells. Attenuated, non-replicating viruses are at present preferred as VACV for safety reasons. A problem may arise concerning their lack of immunogenicity. Through the deletions of non-essential genes, vaccination vectors are therefore developed based on attenuated rVACV capable of replication, which induce a strong immune response. Genes of various immunological adjuvants (e.g., genes for cytokines and costimulatory molecules) are inserted into the vectors for the purpose of eliminating the influence of the immunosuppressive mechanisms of tumors. The first part of the work describes our study of the influence of vCCI on biological properties of rVACV derived from the Prague strain. Testing of vCCI deletion and insertion mutants expressing tumor associated protein HPV16 E7 has shown that secreted vCCI attenuated the virus in vivo, which correlated with reduced levels of the corresponding CC chemokines in the blood compared...
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Immunocompetent cells and their importance in immunopathological conditions
Podrazil, Michal ; Bartůňková, Jiřina (advisor) ; Reiniš, Milan (referee) ; Smetana, Karel (referee)
Pokroky v současné imunologii vedou k lepšímu porozumění interakcí mezi imunitním systémem a nádory, což vzbuzuje zájem o využití imunitního systému v léčbě nádorových onemocnění. V úvodní části práce jsou shrnuty teoretické poznatky o mechanismech protinádorové imunitní odpovědi a jednotlivých složkách imunitního systému podílejících se na tomto procesu. Ústřední úlohu v této interakci reprezentují dendritické buňky. Právě jejich využitím v klinické medicíně se dlouhodobě zabývá naše pracoviště. V této práci se věnuji několika dílčím cílům. První z nich je analýza zastoupení jednotlivých subpopulací imunokompetentních buněk v imunoterapeutickém léčivém přípravku na bázi dendritických buněk proti karcinomu prostaty- DCVAC/PCa vyvinutého na Ústavu imunologie, dále praktickým aspektům přípravy této formy aktivní buněčné imunoterapie a její optimalizaci za podmínek správné výrobní praxe. Výsledky této části byly součástí farmaceutické dokumentace, která vedla ke schválení výrobního postupu i zahájení klinických studií u pacientů s karcinomem prostaty regulačními autoritami. Dalším krokem bylo následné praktické testování imunoterapie DCVAC/PCa nejprve v pilotní "first-in-men" aplikaci u pacienta s pokročilým metastatickým karcinomem prostaty a následně klinické hodnocení tohoto preparátu v rámci 2...
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