Figure 1.

Dendritic Cell Entry into Mouse Dermal Lymphatic Capillaries Induces Mobilization of CCL21

(A) Mouse dermal lymphatic capillary stained for LYVE1 (green), GOLPH4 (red), CCL21 (white), and nuclei (DAPI, blue). Yellow arrows indicate co-localization of CCL21 and Golph4. Zoom-in of boxed area is shown below.

(B) TAMRA-labeled DCs (red) and LYVE1-stained lymphatic capillaries (green) after 3 hr 30′ invasion. Yellow lines indicate the plane of orthogonal section, and yellow arrow highlights a transmigration event.

(C) LYVE1 (green), CCL21 (white), and nuclei (DAPI, blue) of the ear dermis after 3 hr 30′ in presence or absence (control) of TAMRA-labeled DCs (red). Bottom image shows zoom-in of boxed area. White arrows indicate dispersion of CCL21 (yellow arrow in control).

(D) Dot blot graph shows ratio of signal in high intensity CCL21 depots to CCL21 in other areas of LECs. Columns represent mean values ± SD of control (n = 3) and + DC (n = 5) samples of ∼300 μm long lymphatic vessel stretches.

(E) Transmission electron micrograph of CCL21 staining of dermis. Black arrows indicate overlapping LEC tips at cell-cell junctions, yellow arrow detachment of LECs from interstitial extracellular matrix, white arrow rearrangement of collagen bundles, and blue arrow a silver-amplified CCL21 Immunogold label.

(F) Quantification of extracellular CCL21 staining at sites of DC-associated tissue alterations (see E) compared to intact area in same sample or sample devoid of DCs. Bar graph shows mean ± SD of two (–DC) and four (+DC) independent ear samples. Scale bars, 10 μm (A); 50 μm (B and C); 10 μm in zoom-in images; and 500 nm (E).

See also Figure S1.