Interaction of enriched pDCs and PBMCs.

<p>PBMCs were generated from freshly-drawn blood from healthy human donors. PDCs were enriched by MACS technique from PBMCs derived from freshly prepared buffy coats from healthy human donors. (A) Enriched pDCs (white bars) or pDCs supplemented with PBMCs (pDC∶PBMC ratio 1∶10, grey bars) were stimulated with PBS (vehicle), CpG ODN 2336 (1.25 µg/ml) or CpG ODN in the presence of epinephrine (10⁻⁶ mol/l). After 24 hours, IFNA1 release into the supernatant was measured by ELISA. Data is presented as percentage of CpG ODN-induced IFNA1 secretion. (B) In the same experiment, enriched pDCs (white bars) were compared to enriched pDCs seeded into the upper compartment of a two-chamber transwell system containing PBMCs in the lower compartment (pDC∶PBMC ratio 1∶10, hatched bars). Cells were stimulated with PBS (vehicle), CpG ODN 2336 (1.25 µg/ml) or CpG ODN in the presence of epinephrine (10⁻⁶ mol/l). After 24 hours, IFNA1 release into the supernatant was measured by ELISA. Data is presented as percentage of CpG ODN-induced IFNA1 secretion. (C) Absolute IFNA1 levels of corresponding conditions in (A). CpG = CpG ODN 2336; epi = epinephrine. * p<0.05; *** p<0.005; statistical comparisons are indicated by brackets.