Impact of DC-selective DN Rac1 expression on DC migration and macropinocytosis in vivo. (A) FITC (2 mg) was applied to the shaved abdomens of Tg⁺ and WT mice, and the draining (inguinal and axillary) LNs were harvested 24 hours later. Inguinal LNs and axillary LNs from each mouse were combined, subjected to collagenase/DNase digestion, and stained with anti-CD11c mAb and PI. Dot plots of axillary LNs from representative mice are gated on PI^- cells, with FITC and CD11c staining as indicated. The mean (± SD) numbers of FITC⁺ cells in the combined inguinal and combined axillary LNs from single mice are shown for 3 mice per group. Data are from one experiment of 3 performed, all with similar results. (B) Immunofluorescence staining of cryostat sections from spleens of naive (left) or LPS-injected (4 hours, right) mice. WT and Tg⁺ mice were stained with the following mAbs: B220-FITC (green), CD11c-PE (red), and Moma-biotin (+ SA-Cy5, blue). Photographs were taken with a × 20 objective. (C) Mice were injected with FITC-OVA, and analysis of CD8⁺ DCs (upper histograms) and CD8^- DCs (lower histograms) from spleens of control (injected with unlabeled OVA, dotted lines), WT (thin line), and Tg⁺ (thick line) mice was performed 1 hour after injection. Numbers indicate the mean (± SD, n = 3) FITC fluorescence from one experiment. Similar differences were found in 3 independently performed experiments.