Vitamin D3 targets epidermal and dermal dendritic cells for induction of distinct regulatory T cells.

Background: The vitamin D metabolite 1,25(OH)2D3 (VitD3) is a potent immunosuppressive drug and, among others, is used for topical treatment of psoriasis. A proposed mechanism of VitD3-mediated suppression is priming of dendritic cells (DCs) to induce regulatory T (Treg) cells.

Objective: Currently, there is confusion about the phenotype of VitD3-induced Treg cells and the DC-derived molecules driving their development.