Cooperation between mDCs and pDCs enhances T-cell stimulation capacity without changes in cytokine production. (A,B) Costimulatory molecule expression was measured by flow cytometry on pDCs (A) and mDCs (B) after stimulation with CpG or LPS, as indicated. The cells were cultured alone (■) or together (), and the results are reported as the percentage of CD80⁺ and CD40⁺ cells in each population. One representative experiment of 50 is shown. (C) The effect of mDC/pDC cooperation on CD40 expression for 10 different donors was determined as in A and B. The percentage of CD40⁺ cells was determined for pDCs in the presence of LPS (left panel) and mDCs in the presence of CpG (right panel) from 10 different donors cultured alone (single culture) or together (coculture). (D) CD16⁺ or CD1c⁺ mDC subsets in the presence of CpG (top panel) and pDCs in the presence of LPS (bottom panel) were cultured in isolation (single culture) or together (coculture), and the percentage of cells expressing CD40 is shown. The indicated mDC subset was cultured in isolation (■) or with pDCs (), whereas pDCs were cultured in isolation (■) either with CD16 mDC subset (gray striped bar) or CD1c mDC subset (▩). One representative experiment of 3 is shown. (E) Measurement of the indicated cytokines in the supernatants of mDCs (■) or pDCs (□) cultured in isolation or together (▩) in presence of LPS or CpG, as indicated. One representative experiment of 5 is shown. (F,G) T-cell stimulation by DC under the different culture conditions was measured as percentage of proliferating cells. CFSE-loaded T cells were cultured with the following: autologous pDCs (□), allogeneic mDCs (△), or a 1/1 mix of the 2 DC types (●) at the indicated total DC/T-cell ratios, in presence of CpG (F); allogeneic pDCs (□), autologous mDCs (△), or a 1/1 mix of the 2 DC types (●) at the indicated total DC/T-cell ratio in presence of LPS (G). One representative experiment of 3 is shown.