Permeabilization assay of DCs previously labeled with the anti-CD11c mAb.

(A) Dual DC labeling with ethidium bromide (EB) and anti-CD11c antibody (FITC). The upper panel represents the DCs labeled with just the unrelated control antibody (Ct-Ab); the central panel represents the DCs labeled with anti-CD11c mAb and incubated with ethidium bromide alone (Ct-CD11c); the lower panel represents the DCs labeled with anti-CD11c mAb and incubated with ethidium bromide plus 5 mmol/L ATP (ATP-CD11c) for 15 minutes at 37°C. (B) The top histogram represents the fluorescence profile of CD11c⁺ cells incubated with 10 μmol/L ethidium bromide, either with (ATP) or without (Ct) 5 mmol/L ATP. The M1 marker defines the threshold for defining cell permeabilization. The bottom histogram represents the fluorescence profile of the DC population labeled with anti-CD11c mAb (CD11c) or with unrelated control antibody (Ct-Ab).