FITC dextran and HRP uptake by the two DC subpopulations is mediated through receptors for mannose polymers. The experiments of FITC dextran uptake were performed on day-6 CD1a precursors by double color fluorescence (A and C) and on day-11 CD14-derived DCs (B and D; see legend to Figs 3 and 4). The uptake of HRP was performed on day-6 and day-11 CD1a⁺- and CD14-derived cells (E and F ). (A and B) Cells were pulsed for 15 minutes at 37°C with various concentrations of FITC dextran in the absence or in the presence of 1 mg/mL mannan. (C and D) Cells were pulsed for various times at 37°C with 0.1 mg/mL FITC dextran in the absence or in the presence of 1 mg/mL mannan. (E and F ) Cells were pulsed for 15 minutes at 37°C with various concentrations of HRP in the absence or in the presence of 1 mg/mL mannan. Results of each panel are representative of three experiments or more.