| Abstract [eng] |
Myeloid-derived suppressor cells (MDSCs) are a population of immunosuppressive cells involved in the formation of the tumor microenvironment, suppression of antitumor immune responses, and the development of treatment resistance. Their differentiation and functions may be influenced by various microenvironmental signals, including β-adrenergic signaling. The aim of this master’s thesis was to evaluate the effects of different isoproterenol concentrations on the phenotype, gene expression, and functions of MDSCs derived from human peripheral blood mononuclear cells (PBMCs). The objectives of the study were to generate MDSCs from PBMCs using the STAR protocol, perform their morphological and phenotypic characterization, and assess the effect of isoproterenol on MDSC differentiation and gene expression. During the study, PBMCs were isolated from human peripheral blood and differentiated in vitro into MDSCs using GM-CSF and IL-6 cytokines. Throughout differentiation, the cells were exposed to different concentrations of isoproterenol. Following differentiation, CD33⁺ cells were enriched by magnetic selection, cellular morphology was evaluated by light microscopy, phenotype was assessed by flow cytometry, and gene expression was analyzed using RT-qPCR. The study was conducted in 2026 at the Immunology Laboratory of the National Cancer Institute. The results showed that during differentiation, the cells acquired a heterogeneous morphology, including round suspension cells, adherent elongated cells, and cellular clusters. Flow cytometry analysis demonstrated that CD33⁺ magnetic selection enriched the sample with myeloid-derived cells; however, the resulting cell population remained heterogeneous. Differences in the expression of CD33, CD14, and HLA-DR markers were observed when comparing control cells with cells treated with 10 µM isoproterenol. RT-qPCR analysis revealed more pronounced gene expression changes in CD33⁺ cells than in the CD33⁻ fraction, particularly for IDO1, IL-1β, IL-10, and COX2. These findings indicate that the effects of isoproterenol were most evident in CD33⁺ myeloid-derived cells, especially at the 10 µM concentration, and that the observed changes may be associated with inflammatory and immunosuppressive processes. |
