Loss of VCAM-1 in lymphatic collectors reduces rapid DC migration. (A–F) A FITC painting experiment was performed in the TPA-inflamed ears of tamoxifen-treated Cre⁺ (Prox1-Cre^ERT2 Vcam1^fl/fl) and Cre⁻ (WT or Vcam1^fl/fl) mice. (A) Schematic depiction of the experiment. (B) FACS gating scheme on auricular LNs. (C–F) Analysis of absolute numbers (C and E) and percentages (D and F) of FITC⁺ (C and D) and FITC⁻ (E and F) migratory (CD11c⁺ MHCII⁺) DCs. Pooled data from two similar experiments are shown (n = 10 mice per group). Each dot represents a value from one mouse. (G–I) Crawl-in experiments were performed with WT DCs in ear skin explants of Cre⁺ and Cre⁻ mice. (G) Representative images of DCs in and around capillaries and collectors. Scale bars, 50 µm. Yellow arrows show DCs that did not enter but remained attached to the abluminal side of the collector. (H) Quantification of the ratio of DCs inside the vessel, in comparison of all DCs counted per image. Left: Capillaries (cap). Right: Collectors (col). (I) Quantification showing the ratio of DCs attached to the abluminal side over all DCs colocalizing (i.e., inside or outside) with the vessel. Average ratios of all the images analyzed in the same experiment (n = 4 experiments; two or three explants/condition/experiment) are connected by a line. (C–F) Unpaired Student’s t test. (H and I) paired Student’s t test. *, P < 0.05; and **, P < 0.01.