Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycaemia due to insulin production/secretion disorder or insulin resistance caused by various pathogenetic mechanisms. T helper cells (Th) play an important role in the pathogenesis of the disease. In our study, peripheral blood mononuclear cells (PBMC) were isolated from peripheral blood samples from newly diagnosed, 1 year and 5 year type 1 diabetes (T1D) patients (8 patients) and 8 healthy controls, and cultured for 24 hours under unstimulated and stimulated conditions. After culture, the cell ratios of Th1, Th2, Th17, and regulator T (Treg) and the intracellular levels of IFN-γ, TNF-α, IL-10, TGF-β, IL-5, IL-13, IL-17 and IL-21 cytokines were evaluated using Flow Cytometry; whereas mRNA expressions of the transcription factors T-bet, GATA3, ROR-γt and FOXP3 of these cells were determined by Real-Time PCR. Reduced CD4+CD25high cell ratios were detected in newly diagnosed T1D patients under unstimulated conditions. CD4+CD25high cells were found to be reduced in the newly diagnosed and 1 year group of patients compared to healthy controls under IL-2 stimulated conditions. Intracellular IFN-γ and TNF-α levels were low in all patients under unstimulated and IL-12 stimulated conditions. IL-17A and IL-21 were found to be high in patients with unstimulated and IL-6 stimulated conditions. Expressions of IL-10 and TGF-β have been observed to be reduced in patients. Th1/Th2, Th17/Treg and Th1/Treg ratios were higher in the patient groups. FOXP3 and GATA3 mRNA expressions were found to be low in patients, while RORγt and T-bet mRNA levels were higher than healthy controls under stimulated and unstimulated conditions. Our results suggest that Th cell subgroups play an important role in the pathogenesis of T1D.


B. Aydin Ozgur: None. S. Cinar: None. D. Ozturk: None. E. Coskunpinar: None. A.O. Gurol: None. M. Yilmaz: None.

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