Figure 4. Sampling of differentially labeled GP microparticles by CD11c⁺ DCs.

FITC-labeled GPs (green) or APC-labeled GPs (blue) particles were administered to mice by gavage, as described in Materials and Methods. APC-GPs were either (Panel A) co-gavaged with FITC-GPs (GP+GP) or (Panel B) administered to mice 1 hr after FITC-GPs (GP>GP). Twenty-four hours later PP were collected, cryosectioned, immunostained with PE-labeled CD11c (arrowheads; red) and viewed by confocal laser scanning microscopy. The top pair of panels is a merge of the FITC, APC and PE channels, the middle panels are red and green, and the bottom red and blue, as indicated by the vertical annotation on right. In the left panels, the scale bar corresponds to 100 μm, while the scale bar in the right panel corresponds to 20 μm.