Ανοσοβιολογία των δενδριτικών κυττάρων (Bachelor thesis)
Dendritic cells (DCs) of patients with multiple myeloma (MM) are functionally defective and fail to induce tumor-specific immune responses in vivo. Stimulation of DCs by MM-associated antigens ex vivo may overcome suppression induced by tumor microenvironment. Loading of DCs with the total antigenic array of myeloma cells is preferable to the idiotype which is weakly immunogenic. The study objective was the stimulation of DCs from MM patients by autologous tumor antigens, and the assessment of specificity of the in vitro induced T cell responses. Twenty patients with MM at diagnosis or relapse were enrolled in the study. DCs were produced by culture of peripheral blood monocytes in the presence of GM-CSF and IL-4, and were tested by flow cytometry and allogeneic mixed lymphocyte reaction (MLR). Autologous myeloma cells (AMC) were isolated from bone marrow aspirates using anti-CD138 magnetic microbeads. DCs were stimulated either by phagocytosis of apoptotic bodies from irradiated AMC or transfection with total RNA of AMC by electroporation (in 14 and 7 cases, respectively). After TNFa-induced maturation, stimulated DCs were cocultured with autologous lymphocytes in the presence of IL-2. The specificity of the in vitro expanded T cells was assessed by colorimetric cytotoxicity assay against AMC targets or by ELISpot technique for the enumeration of cells that secrete IFN-g after incubation with AMC (in 16 and 5 cases, respectively). In vitro generation of DCs with normal immunophenotype and function was feasible in all patients. With optimization of electroporation conditions, the rate of viable DC transfection reached 80%. A significant CD8+ T cell-mediated cytotoxic activity against AMC (>10%) was detected within the in vitro expanded lymphocytes. Induction of anti-MM specific cytotoxic T cells was successful in 9 out of 11 cases by loading of DCs with apoptotic bodies, and in 4 out of 5 cases by transfection of DCs with RNA. ELISpot analysis revealed the presence of CD4+ and CD8+ T cell-mediated specific responses, that were induced either by apoptotic body-stimulated (3 out of 3 patients) or by RNA-loaded DCs (2 out of 2 patients). The frequency of IFN-g-producing T cells was 70-141 and 20-60 per 10^5 cells, respectively. In conclusion, ex vivo stimulation of DCs from MM patients by whole tumor antigen load is effective in the induction of MM-specific immune responses, and may provide a platform for the design of immunotherapy protocols.
|Alternative title / Subtitle:||Συγκριτική μελέτη in vitro διέγερσης δενδριτικών κυττάρων ασθενών με πολλαπλούν μυέλωμα με αποπτωτικά σωμάτια ή ολικό RNA μυελωματικών κυττάρων|
|Institution and School/Department of submitter:||Πανεπιστήμιο Ιωαννίνων Σχολή Ιατρικής Τμήμα Ιατρικής Τομέας Παθολογικός. Κλινική Αιματολογική|
|Keywords:||Δενδριτικά κύτταρα,Πολλαπλό μυέλωμα,Ανοσοθεραπεία καρκίνου,Ειδικές ανοσιακές απαντήσεις,Αντιγόνα των μυελωματικών κυττάρων,Αντιγονική διέγερση των δενδριτικών κυττάρων|
|Appears in Collections:||Διδακτορικές Διατριβές|
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