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| Identifier |
000355309 |
| Title |
Μελέτη των Τ ρυθμιστικών κυττάρων στο περιφερικό αίμα και το μυελό των οστών ασθενών με χρόνια ιδιοπαθή ουδετεροπενία |
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Author
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Αντωνίου, Αντωνία
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Thesis advisor
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Παπαδάκη, Ελένη
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| Abstract |
Introduction: Functional and/or quantitative changes of T-regulatory (T-reg) cells have been implicated in the pathophysiology of autoimmune diseases. CIN is bone marrow (BM) failure syndrome characterized by increased apoptosis of granulocyte progenitor cells due to the presence of activated T cells with myelosuppressive properties. There role of Tregs in CIN has not been studied.
Aim of the study: To investigate the frequency and the function of Tregs in CIN patients and probe the underlying mechanisms implicated in their abnormalities, if any.
Patients and Methods: 50 CIN patients and 20 age and sex-matched healthy controls were included in the study. All patients fulfilled the diagnostic criteria for CIN. We evaluated the frequency of FOXP3+ cells in the CD4+/CD25high T cell population in the peripheral blood and BM using flow cytometry. Flow cytometric analysis was performed in the CD4+CD25+ T cell fraction. FOXP3 mRNA levels of bead-sorted CD4+CD25+ T cells were measured using real-time PCR. In matters of function, we performed suppression assays using bead-sorted CD4+CD25- and CD4+CD25+ T cells from 2 patients with CIN and 1 healthy control. Finally we assessed IL-17 levels in serum and long-term BM culture (LTBMC) supernates of CIN patients and healthy controls using ELISA as IL-17 levels reflect the Th17 cell numbers and there is evidence of a mutually exclusive relationship between these pro-inflammatory cells and Tregs.
Results: CIN patients displayed statistically significant low number of total lymphocytes (1632±493) and CD4+ T-cells (765±281) compared to healthy controls (2575±559 and 1096±308 respectively) (P<0.0001 and P<0.0001, respectively). The percentage of FOXP3+ cells within CD4+/CD25high T cells (FI >3x101) was significantly decreased in CIN patients (57.77%±15.77%) compared to controls (72.95±12.23%) (0.80%±0.49%, P=0.0005).Interestingly however, a parallel measurement of Treg cell proportion in peripheral blood and BM specimens of CIN patients (n=6) showed statistically significant increased percentage of FOX3+ cells within the CD4+/CD25high T-cells (FI>3x101) of BM (68.51%±11.88%) compared to peripheral blood (52.20%±12.77%, P=0.0005 suggesting a possible accumulation of Tregs in patients’ BM. Real-Time PCR assay confirmed that there is a statistically significant decrease in the expression of the FOXP3 mRNA in bead-sorted CD4+CD25+ T cells of CIN patients (n=11) compared with healthy donors (n=3, P=0.0293). Serum IL-17 levels did not differ significantly between CIN patients (5.41±7.98 ng/ml) and healthy controls (5.99±9.40 ng/ml, P=0.8788) but were statistically significant increased in patient LTBMC supernatants (4.09±6.20 ng/ml) compared to healthy controls (0.69 ±1.82 ng/ml) (P=0.0268). Finally, in 2 patient 1 healthy control co-culture suppression assays, bead-sorted CD4+CD25+ Treg cells from healthy donors suppressed CFSE-labeled CD4+CD25- T responder cells much more effectively than CD4+CD25+ Treg cells from CIN patients. CFSE signal was measured on Day 3 and Day 7 of co-culture using flow-cytometry.
Conclusions: CIN patients display decreased number of Tregs and decreased expression of FOXP3 mRNA in the peripheral blood. There probably is an accumulation of these cells in the BM in an attempt to suppress 4
the local immune reactions mediated by activated T cells and pro-inflammatory Th17 cells which produce higher levels of IL-17 in LTBMC supernates of patients with CIN . The Treg cell function also seems to be defective in CIN patients but more investigation is needed in order to support this postulation.
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| Physical description |
53 σ. : πιν. ; 30 εκ. |
| Language |
Greek |
| Subject |
Autoimmune Diseases immunology |
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T-Lymphocytes, Regulatory immunology |
| Issue date |
2008-12-15 |
| Collection
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School/Department--School of Medicine--Department of Medicine--Post-graduate theses
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Type of Work--Post-graduate theses
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| Notes |
Πρόγραμμα μεταπτυχιακών σπουδών: "Κυτταρική και γενετική αιτιολογία, διαγνωστική και θεραπευτική των ασθενειών του ανθρώπου" |
| Views |
170 |
Μελέτη των Τ ρυθμιστικών κυττάρων στο περιφερικό αίμα και το μυελό των οστών ασθενών με χρόνια ιδιοπαθή ουδετεροπενία
