Induction of T-cell activation by pDCs vs cDCs. (A) Immature or mature pDCs and cDCs were cultured with OT-II CD4⁺ T cells in the presence of OVA peptide (10 μg/mL) for 72 hours, and T-cell CD25 expression was analyzed by flow cytometry. The unfilled histogram shows the negative control. Representative histograms are shown, and statistical analysis is shown in the bar chart. *P < .05 compared with immature pDCs by Kruskal-Wallis test. (B) T-cell proliferation was assessed by [³H]thymidine incorporation after 72 hours of culture with DCs. (C) Analysis of cell proliferation by [³H]thymidine incorporation on T cells stimulated by DCs loaded with decreasing concentrations of OVA peptide (10 μg/mL to 3.2 ng/mL) for 72 hours.