DC entry into lymphatic collectors depends on CCR7, talin1, and integrin β1. (A and B) Ears were split along the cartilage and dorsal and ventral whole-mounts stained for CD31 and LYVE-1. (A) Experimental setup. (B) Image of the vascular network at the rim and the center of the dorsal and ventral ear skin. (C and D) Crawl-in experiments: dorsal ear skins were prestained with fluorescent anti-CD31 and anti–LYVE-1 and incubated with LPS-matured DCs and imaged at the indicted time points. Pictures in D were taken in highlighted areas of C. The yellow arrow in C shows where the first sequence of Video 5 was recorded. Representative pictures from five experiments are shown in B–D. (E–K) 1:1 mixtures of fluorescently labeled WT and KO DCs (CCR7^−/−, Tln1^−/−, or Itgb1^−/−) were incubated on dorsal ears skin explants for 4 h. Explants were stained for CD31 and LYVE-1 before analysis. (E–J) Representative images (E, G, and I) and and corresponding quantifications (F, H, and J) of KO:WT DC ratios in capillaries (cap) and collectors (col). (K) Quantification of the ratio of DCs attached to the abluminal side (see yellow arrows in I for Itgb1^−/− DCs) over total DCs colocalizing (i.e., inside or outside) with the collector. Each dot represents the ratio from one explant (n = 4–10 explants per condition). Ratios from the same explant in F, H, J, and K are connected by a line. Statistical significances either compare with the normalized input ratio of 1 or between the groups (connected by lines). Scale bars, 100 µm (in B and C), and 50 µm (in D, E, G, and I). (F, H, J, and K) Paired Student’s t test. *, P < 0.05; **, P < 0.01; and ****, P < 0.0001.