TPT inhibits epidermal Langerhans cell migration in vivo. (A) A lower frequency of hapten-bearing cells were detected in the draining LNs of TPT-treated mice. The mice were treated with TPT (0.1 mg/kg/d, intraperitoneally) or vehicle alone for 5 days. On the last day of TPT treatment, all mice were painted on the dorsum of their ears with 10 μL 1% FITC in acetone/dibutylphalate (1:1). 24 hours later, auricular LNs (ALNs) were taken, and single-cell suspensions were prepared, stained with PE–anti-CD11c, and then analyzed on FACScan. (Ai) ALN cells from naive mice, staining with PE-CD11c. (Aii) ALN cells from FITC-painting mice. (Aiii) ALN cells from untreated mice stained with PE-CD11c. (Aiv) ALN cells from TPT-treated mice stained with PE-CD11c. Numbers indicate percentage of cells present in quadrants. (B) TPT-treatment reduced the FITC-bearing cell number in the draining LNs. The FITC-bearing cell number was calculated from the percentage of FITC⁺ cells and total ALN cell number. The data are representative of 3 independent experiments with similar results. Error bars indicate SD.