Altered B cell motility in FDC-ablated pLNs. Two-photon laser-scanning microscopy of explanted pLNs from CD21-DTR chimeras that were injected with CFSE-labeled B cells and CMTMR-labeled T cells 5 d before imaging and control (Ctrl) or DTx treated 2 d before imaging. (A) 114-µm maximum intensity z-projection view from a video of control- and DTx-treated LNs, showing the location of CFSE-labeled B cells at a single time point together with measured trajectories of ∼50 B cells. This image corresponds to Videos 1 and 3. Bar, 100 µm. (B and C, left) Instantaneous velocities (B) and turning angles (C) of B cells in pLNs. Central dot plots show medians for each cell track from one representative experiment. Right bar graphs show the mean of the medians from three independent experiments, bars represent means, and circles represent individual experiments. (D) Mean of displacement squared <R2> over time. Symbols represent means, and error bars represent SEM. Data are representative of three experiments with at least 50 tracks in each. Statistical analysis was performed with the two-tailed unpaired Student’s t test.
