KIR engagement prevents lipid raft polarization and signaling protein phosphorylation.

Confocal analysis of serial optical sections collected at 0.3-μm intervals. (A) 4D4 CTL clone labeled by FITC–CT-B (green) was stimulated with PKH26-labeled tumor cells (blue). 4D4 CTL clone was conjugated either with RCC-6 (upper panels) or RCC-7 (lower panels) and incubated 5 minutes at 37°C. After fixation, cells were stained with anti-Ptyr mAb (red). This picture represents an overlay and the side-side picture of the overlay showing labeling lipid rafts (FITC–CT-B) or tyrosine-phosphorylated proteins (Ptyr-Cy5) as indicated. (B) Stimulated 4D4 CTL clone was stimulated as in (A) and then stained with anti-CD3 mAb (green) and anti-Ptyr mAb (red). Original magnification × 63.