Figure 5.

VD could also function directly on T cells to shape T cell responses. CD4⁺CD62L⁺ cells from C57BL/6J or C57BL6 Foxp3^gfp reporter mice were cultured in the Th0 or Th17-polarizing conditions with immobilized anti-CD3 and soluble anti-CD28 instead of APCs, in the presence or absence of 1uM VD. (A,B) qRT-PCR results showed VDR and CYP24 mRNA relative expression on CD4⁺ T cells stimulated in Th0 or Th17 conditions without APCs for 24 h in CTRL (without VD) and VD groups. Data are presented as the mean ± SEM. ^*P < 0.05, ^**P < 0.01, ^****P < 0.0001 vs. control group. (C–E) naïve CD4⁺ T cells from C57BL6 Foxp3^gfp reporter mice were cultured in Th17-polarizing conditions with immobilized anti-CD3 and soluble anti-CD28 (+coating) or in the presence of APCs (+APCs), in the presence or absence of 1 uM VD for 3 days. Expression of IL-17A and GFP⁺ (Foxp3⁺) gated on CD4⁺ T cells were checked by flow cytometry. Representative flow data (C), statistical analysis of IL-17A expression in coating system between two groups (D) and IL-17A suppression ratio by VD in both system were shown (E). Data are presented as the mean ± SEM (experiments were repeated at least for 5 times). ^*P < 0.05, ^****P < 0.0001 vs. control group.