Video 4.
Video from two-photon intravital microscopy of the experiment described in Fig. 7 D, showing WNK1-expressing control B cells (blue), WNK1-deficient (KO) B cells (red), and GFP-expressing OT-II CD4+ T cells (green), showing interactions between OT-II T cells and control B cells (open arrowhead) or mutant B cells (filled arrowhead); transferred polyclonal CD4+ T cells are not shown. Images were recorded every 30 s. Time is shown in min:s. In the first part of the video, the scale bar represents 20 μm; in the second higher magnification part of the video, the scale bar represents 10 μm. Analysis of B-T interaction times is shown in Fig. 7 I.