Effect of DC maturation stimulus on expansion of Treg's. (A) Maturation status of immature DCs (IDC) or DCs matured with inflammatory cytokines (Cyt-DC), FcγRIIB blockade (RIIB), CD40 ligand (CD40L), poly I:C, or LPS was monitored by examining the surface expression of CD83, CD80, CD86, and HLA-DR. The figure represents 1 of 3 similar experiments. (B) T cells were cultured either alone (T alone), or with immature DCs (IDC), or DCs matured with inflammatory cytokines (Cyt-DC), FcγRIIB blockade (RIIB), CD40 ligand matured DCs (CD40L), or the Toll-like receptor ligands poly I:C, or LPS. After 7 days of culture, the presence of FOXP3⁺ T cells was monitored by flow cytometry. The figure represents 1 of 5 similar experiments. The numbers represent the percentage of FOXP3^high cells in the gated area. (C) As in panel B, different types of mature DCs were tested for the ability to induce Treg's in the CD4⁺ CD25^- population. The plots represent 1 of 3 similar experiments.