The recruitment of pCD19 was decreased in WAS memory B cells, but the recruitment of phosphorylated SHIP (pSHIP) was increased in WAS memory B cells. (A-D) TIRFM and IRM analysis of pCD19 staining in the contact zone of HCs and WAS (P1-12) memory and naive B cells incubated with membrane-tethered Fab′–anti-Ig. The colocalization coefficients between BCR and pCD19 staining were determined using NIS-Elements AR 3.2 (F). Shown are representative images (A-D) and the average MFI (E) or colocalization coefficients (F) (±SD) from ∼50 individual cells of 3 independent experiments. (G-J) TIRFM and IRM analysis of pSHIP staining in the contact zone of HCs and WAS (P1-12) naive and memory B cells incubated with membrane-tethered Fab′–anti-Ig. Shown are representative images (G-J) and the MFI (±SD) of pSHIP (K) in the B-cell contact zone from 3 independent experiments. TIRFM analysis of the spatial relationship of BCR with pSHIP (G-J) in the contact zone of B cells incubated with membrane-tethered Fab′–anti-Ig. The colocalization coefficients between BCR and pSHIP staining were determined using NIS-Elements AR 3.2 software (L). Bars, 2.5 μm. *P < .01, compared with WAS naive or memory B cells.