DOCK2 deficiency impairs the lytic synapse formation. (A) PKH26-labeled WT and DOCK2^−/− NK cells were mixed with CFSE-loaded target cells, YAC-1 and EL4-Rae1ε, for 10 minutes at a ratio of 1:1, and conjugate formation was analyzed without fixation. Data are representative of 2 independent experiments. (B) WT and DOCK2^−/− NK cells were mixed with EL4-Rae1ε cells for the indicated times to analyze localization of GFP-tagged Rae1ε in the conjugates. Scale bar, 5 μm. Data are expressed as the percentages of the conjugates with polarized accumulation of Rae1ε (the mean ± SD) of 3 independent experiments. In each experiment, more than 30 cells were analyzed per group. **P < .01. (C) WT and DOCK2^−/− NK cells were mixed with YAC-1 cells for the indicated times to analyze localization of perforin and F-actin in the conjugates. Scale bar, 5 μm. (D) After pretreatment with latrunculin B (8 μg/mL) for 2 hours, WT NK cells were mixed with YAC-1 cells for the indicated times, and the effect of blockade of actin polymerization on perforin localization was analyzed. Scale bar, 5 μm. Mock, DMSO. In (C,D), data are expressed as the percentages of the conjugates with polarized accumulation of perforin or F-actin (the mean ± SD) of 3 independent experiments. In each experiment, more than 30 cells were analyzed per group. *P < .05; **P < .01.