Effect Of Il-21 On Treg Cells In Peripheral Blood Mononuclear Cells In The Pathogenesis Of Graves Disease

Objective:1. Examined the expression levels of Foxp3 and IL-10 mRNA, and the plasma level of IL-10 protein in three groups. To investigate whether Treg cells were involved in the pathogenesis of GD. 2.Examined the expression levels of Foxp3 and IL-10 mRNA, and the plasma level of IL-10 protein with IL-21 in three groups. To explore the role of IL-21 in regulating the expression of peripheral blood Treg cells in the pathogenesis of Graves disease.Methods:Thyroid function indexes and autoantibodies were determined by electrochemical luminescence detection. Peripheral blood mononuclear cells(PBMCs) were extracted, then, cultured in the presence or absence of IL-21 in vitro. Enzyme-linked immunosorbent assay(ELISA)was used to measure the level of IL-10 protein. And Real-time PCR was used to detect the expressions of Foxp3 and IL-10 mRNA.Results:1. Compared to eGD and control group, there were significant differences in the levels of thyroid function indexes and autoantibodies in GD group(P < 0.05), however, there was no difference between controlgroup and e GD group(P>0.05). 2. Before IL-21 stimulation, compared to eGD and control groups, the expressions of Foxp3, IL-10 mRNA and the level of IL-10 protein were significantly higher in GD group(P<0.05); but there were no significant differences between eGD group and control group(P>0.05). After IL-21 stimulation, the expressions of Foxp3, IL-10 mRNA and IL-10 protein levels were decreased markedly in all three groups,among which GD group showed the greatest change.(P<0.05).Conclusions:1. Compared to eGD group and control group, Treg cells specific transcription factor Foxp3 mRNA; Cytokines IL-10 mRNA; IL-10 protein expression levels were significantly higher in GD group. This suggests that Treg cells and its downstream effector molecules have involved in the pathogenesis of GD. 2. After IL-21 stimulation, the expressions of of Foxp3, IL-10 mRNA and IL-10 protein levels were decreased markedly. This suggests that IL-21 may inhibit the differentiation of Treg cells and the production of IL-10, therefore decreasing the number of Treg cells and the ability of suppressing effector T cells, thus should be involved in the pathogenesis of GD.