Levels of TGF-β₁ in serum and culture supernatants of CD4⁺CD25⁺ T cells from patients with non-segmental vitiligo

Compelling evidences support an autoimmune basis of non-segmental vitiligo, and dysregulation of CD4⁺CD25⁺ regulatory T cell (Treg) is assumed to contribute to the pathogenesis of vitiligo. Serum levels of transforming growth factor-β (TGF-β), an important immunoregulatory cytokine produced by Treg cells, has been reported significantly decreased in patients with vitiligo. However, relation between the decrease in TGF-β and the dysfunction of Treg cells in pathogenesis of vitiligo was still undemonstrated. To further reveal the role of TGF-β in vitiligo, 46 patients with non-segmental vitiligo and 25 age- and sex-matched healthy control subjects were enrolled in the study. CD4⁺CD25⁺ T cells isolated from peripheral venous blood with a CD4⁺CD25⁺ regulatory T cell isolation kit were cultured with or without anti-CD3 mAbs and anti-CD28 mAbs for 4 days. The TGF-β1 levels in serum and culture supernatants were detected by enzyme-linked immunosorbent assay in both groups. We have found that the TGF-β1 levels both in serum and culture supernatants in the presence of anti-CD3 mAbs and anti-CD28 mAbs were decreased in the active vitiligo group when compared with the control group or stable vitiligo group, and were negatively correlated with the percentage of involved body area. These results suggested that TGF-β may play a role in the pathogenesis of non-segmental vitiligo related to the suppressive function of Tregs.