Myosin II-ATPase activity is essential for DC confined migration. (A) After a pretreatment of 20 hours with TSLP in the absence or presence of blebbistatin (50μM) or a mix of ML7/Y27632 (10μM/10μM), DCs were loaded in the entry chamber of the channels. The number of DCs entering the channels during a 12-hour time-lapse movie was quantified. TSLP induced a 4-fold increase in the capacity of DCs to enter microchannels compared with control. Blebbistatin and ML7Y27632 significantly inhibited TSLP-induced migration. Data are mean ± SD; n = 3. **P < .01. ***P < .005. (B) After 20 hours of culture in the absence or presence of blebbistatin (50μM), DCs were loaded in the entry chamber and allowed to spontaneously enter in the channels. Phase-contrast images were recorded. Kymographs were processed and analyzed to extract instantaneous speed of individual cells. Distribution of the median speed of DCs precultured in TSLP in the absence or presence of blebbistatin is significantly different (P < .05). Data are from 1 representative of 2 independent experiments.