Figure 3. Measurement of soluble or cellular antigens uptake by flow cytometry.

(A) Endocytosis of soluble tracers. MoDC, purified BDCA-4+ primary PDC or GEN3 cells were incubated for 2 hours at 4°C (filled curves) or 37°C (open curves) with Ovalbumin, Lucifer yellow and Dextran. Mean fluorescence intensity (MFI) values are indicated. Results are representative of two experiments. (B) Uptake of cellular material. PKH26-stained B cells were induced into apoptosis, necrosis, or were opsonized with CD20 mAb Rituximab or left untreated. They were then incubated with MoDC or GEN3 for 2 hours and stained as described in materials and methods section. PKH26 fluorescence, measuring cellular material uptake, was analyzed gating on MoDC (CD11b^pos) or GEN3 (CD4^posCD36^pos) not involved in cell conjugates (CD19^negCD20^neg). Percentages of positive cells at 37°C (open curves), relative to incubation at 4°C (filled curves) are indicated. These data are representative of two independent experiments.