Induction of B-cell polarization is impaired in the absence of WASP.

B cells from WASP⁻ (▪) and WASP⁺ (■) mice were cultured with indicated stimuli for 24 hours, after which they were fixed. Polarized cells were defined as having a tapered cell body and uropods, whereas nonpolarized cells were spherical. Polarized cell frequency was determined. Results are presented as mean values of triplicate experiments, error bars represent 1 SD, and brackets indicate P < .005 using a 2-tailed t test. At least 300 cells were counted in each group, and the data are representative of at least 4 experiments.