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Pathofysiology of a tumour microenvironment of salivary glands cancer
Kuchař, Martin ; Skřivan, Jiří (advisor) ; Pokorný, Jaroslav (referee) ; Lohynská, Radka (referee)
Treatment options for salivary gland carcinomas (SGC), especially advanced ones, are limited. Immunotherapy, particularly therapy with immune checkpoint inhibitors (ICI), has brought significant progress and change in the treatment of malignant tumors. The effect and response to immunotherapy using ICI are largely driven by the characteristics of immune cells in the tumor tissue and, as it turns out, also in the peritumoral tissue. We conducted an immunohistochemical analysis of the expression of the immune checkpoint protein PD-1 and its ligand PD-L1 on the surface of tumor cells as well as tumor-infiltrating immune cells (TIIC) in samples of salivary carcinomas, separately in their centre and at their periphery. In addition to the above, an increasing amount of evidence suggests that resistance to ICI therapy is modulated by the interaction of the Fas receptor (CD95) and Fas ligand (FasL, CD178) between tumor cells and immune cells. We therefore decided to explore the expression and interaction of Fas-FasL between tumor cells and tumor-infiltrating immune cells in the centre of the tumor and in the peritumoral area of salivary carcinoma samples. Differential evaluation of the tumor centre and tumor periphery across various histological subtypes of SGC revealed the role of peripheral TIICs and...
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Úloha osy PD-1/PD-L1 při infekci \kur{Borrelia burgdorferi} u myší
PALOUNKOVÁ, Anna
Borrelia burgdorferi, the causative agent of Lyme disease, induces upregulation of inhibitory immune checkpoint PD-L1 in mice. We studied if the blockade of PD-1/PD-L1 axis by neutralizing antibodies influences the proliferation of T lymphocytes and cytokine milieu in imunological synapsis between murine dendritic cells and T cells in vitro.
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Checkpoint blockade in cancer immunotherapy
Vacková, Julie ; Šmahel, Michal (advisor) ; Černý, Jan (referee) ; Říhová, Blanka (referee)
The immune checkpoint blockade is a novel approach of cancer therapy, which markedly enhanced treatment efficacy of several cancer types. However, the frequency of cancer patients non-responding to this treatment is high. Establishment of predictive markers to distinguish patients suitable for the immune checkpoint blockade would enhance the number of patients receiving benefit from the therapy. This dissertation thesis focuses on the enhancement of efficacy of immune checkpoint inhibitors (ICIs) and predictive markers in experimental models of mouse tumours induced by TC-1 and TC-1/A9 cell lines and its clones with deactivation of interferon (IFN)-γ signalling (TC-1/dIfngr1 and TC-1/A9/dIfngr1), or CD80 molecule (TC-1/dCD80-1). IFN-γ is presumed to be the main inducer of programmed death ligand 1 (PD-L1) and a major histocompatibility complex I (MHC-I). Moreover, PD-L1 expression may predict sensitivity to PD-1/PD-L1 blockade. Non-functional IFN-γ signalling or downregulated MHC-I expression has been associated with resistance to ICIs in some patients. We found that IFNs type I (IFN-α and IFN-β) induced the expression of PD-L1 and MHC-I on TC-1/A9/dIfngr1 tumour cells with reversible downregulation of both molecules. We also showed that deactivation of IFN-γ signalling in TC-1/A9 cells was not a...
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Factors affecting the efficacy of anti-tumor therapy by blocking the PD-1/PD-L1 signaling pathway and predictive biomarkers of this treatment
Majerová, Miriam ; Šmahel, Michal (advisor) ; Krulová, Magdaléna (referee)
In recent years there has been a focus on cancer therapies that use patient's immune system instead of invasive traditional methods. One such method of immunotherapy is using checkpoint inhibitors. Blockade of PD-1/PD-L1 signaling pathway is one of main immunotherapy approaches utilizing patient's immune cells to combat cancer cells. Despite of positives that come along with this blockade, many patients do not respond to treatment. Therefore, better understanding of immune mechanisms and factors that affect the efficacy is needed. Finding and summarizing predictive biomarkers play an important role in selection of patients with highest chances of positive outcome and it could result in higher percentage of positively responding patients. It could also prevent patients from experiencing adverse events and unnecessary discomfort. Key words: immune checkpoints, immunotherapy, inhibitors, PD-1, PD-L1, biomarkers
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The prognostic and predictive role of immune check point inhibitors in ovarian cancer patients
Raková, Jana ; Palich Fučíková, Jitka (advisor) ; Šťastný, Marek (referee)
Epithelial ovarian cancer is the sixth most common tumor disease among women and it is the leading cause of death from all types of gynecologic malignancies. The current standart of care consist of debulking surgery followed by platinum-taxane chemotherapy. Althought some patients benefit from the treatment, most eventually experience platinum-resistance and die from this disease. Immunotherapy based on application of immune checkpoint blockers represents a new treatment strategy in different cancer malignancies. However, emerging clinical data show only limited clinical efficacy of these agents in ovarian cancer patients with objective response rates of 10-15%. Therefore there is a strong need to identify a potential biomarkers, which allows to identify the group of patients, who will benefit the most from this costly treatment. The aim of my diploma thesis was to characterize the prognostic and predictive role of the immune checkpoints within the retrospective and prospective cohort of patients with high-grade serous ovarian cancer (HGSOC). Our study follows, that the expression of PD-L1 molecule and high frequencies of PD-1+ tumor infiltrating lymphocytes (TILs) in tumor microenviroment is significantly correlated with a better prognosis of patients with HGSOC. Moreover, PD-L1 and PD-1...
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