Figure 6. The triple–TLR ligand–treated DCs prevent expansion of Treg cells and exhibit minimal upregulation of PD-L1.

BM-DCs were treated with TLR ligands for 20 hours, and excess TLR ligands were removed. (A and B) Freshly isolated syngeneic splenic T cells were cocultured with TLR ligand–pretreated DCs. Foxp3⁺CD4⁺ cells were evaluated at 24 hours and 48 hours, respectively. Numbers indicate percentage of CD4⁺ T cells positive for Foxp3. (B) BM-DCs were treated with TLR ligands for 20 hours and stained with either anti-CD86 or anti–PD-L1 mAbs to measure levels of the costimulatory molecules. The experiments were repeated twice with similar results. *P < 0.05; **P < 0.01. Results are shown as mean ± SEM.