Morphologic evidence for CCL19-induced endocytosis. Mature DCs that are BC1 cells treated with LPS for 24 hours were incubated with FITC-dextran at 1 mg/mL in the presence or absence of CCL19 for 2 minutes. Following fixation in 4% paraformaldehyde, the fluorescence intensity of the cells was analyzed by confocal microscopy. (A) Endocytosis in the presence or absence (control) of CCL19. Bar represents 50 μm; original magnification, × 60. (B) Immunofluorescence image (right panel) and merged image of CCL19-treated mature DCs with differential interference contrast of the same cell (left panel). Bar represents 5 μm; original magnification, × 360.