1,25(OH)₂D₃ negatively regulates Treg and T_H17 induction in neuro-antigen-specific CD4⁺ T cells.

<p>CD4⁺ T cells isolated from MOG TCR-Tg mice (Vα3.2 and Vβ11 TCR, B6 background) were cultured with MOG_35–55 peptide (25 µg/ml) in the presence of CD3⁺ T cell-depleted splenocytes for 4 days under Treg-polarizing conditions (rTGF-β, 1 ng/ml; anti-IFN-γ, 10 µg/ml; and anti-IL-4, 10 µg/ml) or T_H17-polarizing conditions (rTGF-β, 1 ng/ml; rIL-6, 20 ng/ml; anti-IFN-γ, 10 µg/ml; and anti-IL-4, 10 µg/ml) or T_H1-polarizing conditions (rIL-12, 10 ng/ml; and anti-IL-4, 10 µg/ml) together with 1,25(OH)₂D₃ (VitD, 100 nM). Cells were then stained intracellularly for Foxp3, IL-17, or IFN-γ, respectively. The plots shown are gated on CD4⁺Vα3.2⁺ cells with quadrants drawn based on isotype controls. Data are representative of two independent experiments with at least three mice per group.