Figure 3.

SLE pathogenesis and mechanism of vitamin D on immune cells. UVB light causes apoptosis of cells that release endogenous nucleic acids. The nucleic acids bind to and trigger plasmacytoid dendritic cells to release IFN-α. Mature dendritic cells recruit T helper cells, cytotoxic T cells and B cells. Vitamin D increases protective innate immune response while dampening the over-active immune response. Vitamin D also inhibits the maturation of dendritic cells and suppresses IFN-α production from plasmacytoid dendritic cells as well as IFN-α induced gene expression.