Effect Of Sodium Selenite On Treg Cells In Peripheral Blood Mononuclear Cells In Patients With Graves Disease

Objective:Recently, selenium was used to treat Graves disease and also beneficial to it. However, there has been no reports that selenium affected the immune function of Graves disease at the cellular level so far. It is reported the effect of sodium selenite on Treg cells in peripheral blood mononuclear cells in patients with Graves disease in the present study.Methods:30 untreated GD patients, who got the first visit in outpatient departments of endocrinology departments in the first affiliated hospital of Chongqing Medical University, and 18 age- and sex-matched healthy controls, were enrolled. Their blood samples were taken to relevant laboratory. Chemiluminescence assays was used to detect FT3, FT4, TSH, TPOAb, TgAb. AFS were used to detect the levels of serum selenium; PBMC were extracted. Every subject was divided in 2 sets:one was cultured with sodium selenite, the other in RPMI-1640 medium containing 10% fetal bovine serum as a control. Foxp3 mRNA expression was tested by qRT-PCR, and ELISA was used to detect the secretion of IL-35.Results:(1) The serum sodium selenite levels of GD group are 49.4±15.56 μg/L, and HC group 84.85±18.27 μg/L. Levels of GD group are significantly lower than HC’s(P<0.001);(2) Levels of FT3 and FT4 in GD group are apparently higher than HC’s, on the contrary, TSH are lower(P＜0.001). Thyroid antibodies, such as TgAb, TPOAb, TRAb, are also higher than HC’s(P<0.001).(3) Before the intervention of sodium selenite:Compared with HC group, the expression of Foxp3 mRNA and secretion of IL-35 in plasma are both lower in GD group(P＜0.001).(4) After the intervention of sodium selenite:The expression of Foxp3 mRNA and secretion of IL-35 in plasma are higher than before in both groups(P<0.01,P<0.001).Conclusion:The serum sodium selenite levels of GD group are significantly lower than HC’s, and low selenium levels may promote the development of GD; The reduction function of Treg cells are suggested by lower levels of factors which are related Treg cells, Foxp3 and IL-35. It shows sodium selenite could improve the state of immune disorders by recovering the function of Treg cells.