The number of LECs increases in auricular LNs that drain inflamed ears of WT mice subjected to repeated DTH challenges. A DTH response to oxazolone was induced in the ears of WT mice and maintained by repeatedly applying oxazolone on the ears for 9 days. (A-C) After 9 days, the total numbers of leukocytes (A) and of LECs (B) and BECs (C) were significantly increased in inflamed ears over control (ctr) ears, as determined by quantitative FACS analysis. (D) Immunofluorescence analysis of LYVE-1 (green) and MECA-32 (red) expression confirmed that vascularization was increased in inflamed compared with control ears. Scale bars represent 50 μm. (E,F) Analysis of ear draining auricular LNs revealed that LN weight (E) and cellularity (F) was markedly increased in inflamed compared with control animals. (G,H) Quantitative FACS analysis detected elevated numbers of LECs (G) in LNs draining inflamed compared with control ears, but no change in BEC (H) numbers. (I) Immunofluorescence analysis of LYVE-1 (green) and MECA-32 (red) expression confirmed that lymphatic structures were markedly expanded in LNs draining inflamed compared with control ears. Scale bars represent 100 μm. (J) Differential immunofluorescence staining for LYVE-1 (green) and Ki67 (red) revealed the presence of proliferating LECs (white arrows) in inflamed LNs. Scale bars represent 25 μm. *P < .05; ***P < .001 (compared with control). Error bars are SE.