IL-6 is not crucial for inhibition of phagocytosis in CMV-MoDCs. Monocytes differentiated for 5 days as described below were cocultured with PKH-26–labeled apoptotic fibroblasts for 24 hours. Phagocytic activity was determined as described in “Phagocytosis assays.” (A) Monocytes were differentiated in standard medium (Med), after infection (CMV), with added IL-6 (50 ng/mL), or without GM-CSF (ΔGM). (B) Monocytes were differentiated in the presence of supernatant from MoDCs (SN-MoDC) or CMV-MoDCs (SN-CMV-MoDC) supplemented with medium (NT), IL-6 neutralizing Ab (αIL-6; 15 μg/mL), or isotype control Ab (iso; 15 μg/mL). Results are expressed as the percentage of phagocytic activity relative to MoDCs (100%). Error bars indicate the SD. Representative of ≥ 3 independent experiments.