WASp deficiency impairs DC migration T-cell interaction in the lymph node. Analysis of migratory behavior; (A) velocity, (B) displacement, and (C) persistence of migration of in situ migrating DCs by multiphoton imaging, data are shown as averages ± SEM, C57BL/6 n = 155 from 4 independent experiments, WAS KO n = 151 from 3 independent experiments, P values are indicated (2-tailed Student t test). (D) Schematic representation of parameters assessed for analysis of migration. (E) Immunofluorescent analysis of DCs interacting with antigen-specific T cells, DCs in green, OT-II T cells in red, arrows indicate T cells in contact with DC, arrowheads indicate T cells in close vicinity but not in contact with DCs and right panels are enlarged magnification of indicated area in middle panels and scale bars represent 50 μm. (F) Quantification of T cells in contact with DCs, by immunofluorescence, C57BL/6 n = 9 nonimmunized, n = 14 immunized; WAS KO n = 9 nonimmunized, n = 14 immunized; data are shown as averages ± SEM and P values are indicated (1-way ANOVA). (G) Quantification of T cells in contact with DCs by flow cytometry, n = 2 and data are shown as averages ± SD.