Uptake of fluorescein-labeled recombinant Fab fragments by monocyte-derived dendritic cells.

Fluorescence-labeled recombinant Fab fragment was added to monocyte-derived LC at a concentration of 660 μg/mL immediately before terminal differentiation to DC with LPS. After DC differentiation, protein-loaded cells were pipetted onto adhesion slides and fixed with 3% paraformaldehyde. The location of fluorescence within the cells was assessed by confocal microscopy. In cells with DC morphology, bright fluorescence was present in cellular subcompartments with the typical shapes and localization of endosomes.