Fig. 3.

Correlation of vitamin D (VD) plasma levels and immune status exposed a significant association between the 25D and IL-4 producing CD8 T cells. Peripheral blood mononuclear cells (PBMCs) were stained for plasmacytoid dendritic cells (pDCs) [Linage cocktail 3 (Lin3^–), CD303⁺, CD123⁺, CD11c⁺], myeloid dendritic cells (mDCs) (Lin3^–, CD303^–, CD123^lo, CD11c^hi, CD4⁺), regulatory T cells (T_regs) (CD4⁺, CD25⁺, forkhead box protein 3 (FoxP3)⁺; CD8⁺, CD25⁺, FoxP3⁺) and analysed by flow cytometry. In addition, PBMCs were stimulated with phorbol myristate acetate (PMA)/ionomycin overnight and intracellular cytokine staining was performed for interferon (IFN)-γ, interleukin (IL)-17 or IL-4 producing CD4 and CD8 T cells. The frequency of pDCs, mDCs, T_regs and IFN-γ, IL-17 and IL-4-producing CD4 and CD8 T cells were correlated to the 25D (a) and 1,25D plasma levels (b). Significant correlations as revealed by the non-parametric Spearman's correlation test are indicated (GraphPad Prism software).