Immunomodulatory vitamin D effects on regulatory T-cells and cytokines in an in vitro study on patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease affecting various organs. Decreased numbers of regulatory T-cells (Treg cells; CD4⁺CD25^highFoxp3⁺) are associated with the pathogenesis of SLE. A vitamin D deficiency was observed in many lupus patients. In the present study, peripheral blood mononuclear cells were isolated and cultured in the presence or absence of vitamin D, and total Tregs percentage was analyzed by flow cytometry. In addition, the level of expressions of Foxp3, TGFβ, and IL6 genes were analyzed by real-time-PCR. The results indicated that vitamin D treatment increased the percentage of Treg cells, and the expression of Foxp3 and TGFβ, and decreased the expression of IL6 in SLE patients.