Figure 5.

CFSE-labeled, cell lines and tumor cells are selectively captured by CD8⁺CD11c⁺ DCs in vivo. (A) 20 × 10⁶ BaF3 tumor cells, induced to apoptose by 12 h of culture in the absence of IL-3, were injected intravenously; then splenic DCs were examined 2 h later for CFSE-uptake (arrows) as in Fig. 1. The experiments were done in parallel in wild type and DEC-205^−/− mice. Phagocytic DCs in the CD11c⁺ population were 6.3% for C57BL/6 mice and 5.0% in DEC-205^−/− mice. (B) 5 × 10⁶ EL-4 thymoma cells, untreated or induced to apoptose by heavy irradiation (50 Gy) or by osmotic shock, were injected intravenously 2 h later, CD11c⁺ splenocytes were examined for uptake of CFSE-labeled cells (arrows). CSFE-labeled DCs were 0.04% in mice injected with untreated cells, 3.1% after osmotically shocked cells, and 5.15% after irradiated cells.