Kinetics of reappearance of donor-derived langerin+ DCs after DT ablation. Ear explants and CLNs from Lang-DTR-EGFP → B6 (CD45.1) chimeras that had received 3 injections of DT 1 wk apart were prepared at the specified time points after the last DT treatment. For ears, analysis was performed on cells migrating out of CCL21-treated ear explants. Gated DCs (ears, CD11c+ MHCII+; CLNs, CD11cinter to high MHCIIhigh) were analyzed using langerin-EGFP plots. A window corresponding to the langerin+ EGFP+ subset is shown. The percentage indicated for this window corresponds to the percentage of donor-derived, langerin+, EGFP+ cells within the DC gates specified above. Also shown is a confocal microscopic analysis of a section of ear from a DT-treated Lang-DTR-EGFP → B6 (CD45.1) chimera 14 d after the last DT treatment. Staining with anti-langerin (red) and anti-keratin 5 (blue), revealed that donor-derived (EGFP+), langerin+ DCs are located exclusively in the dermis, whereas host-derived (EGFP−), langerin+ DCs are found in the epidermis. Some donor-derived, langerin+ DDCs (marked with a star) are found adjacent to hair follicles. Results are representative of at least two experiments. Ep, epidermis; D, dermis. Bar, 30 μm.