PDCs contribute to B-cell activation within PBMCs. Cells were incubated with CpG-C (3 μg/mL), anti-Ig (10 μg/mL), or a combination of CpG-C and anti-Ig. After 72 hours CD86 was analyzed on CD19⁺ B cells by flow cytometry. Data are presented as mean fluorescence intensity (MFI ±SEM). (A) Total PBMCs (▪) or PBMCs depleted of PDCs (▨) were used (n = 4 independent experiments). (B) Isolated B cells were incubated alone (1 × 10⁵ B cells/200 μL/well) or cocultured with PDCs (1 × 10⁴ PDC/200 μL/well; n = 5 independent experiments; □, B cells alone; ▪, B cells and PDCs).