F-actin dynamics persist in human T cells treated with myosin II inhibitors, but cease completely after subsequent addition of jasplakinolide. Human T lymphoblasts were transduced with Lifeact-GFP (green). Cells were pretreated with Y-27 or left untreated and allowed to interact with planar bilayers coated with anti-CD3 and ICAM-1 (both unlabeled). After full spreading had been reached, jasplakinolide was added to the imaging chamber. Confocal 0.5-µm-thick Z stacks were acquired by confocal microscopy using a spinning disk confocal microscope (Ultraview Perkin Elmer on an Axiovert 200 stand Carl Zeiss) every 2 s for 2 min and are shown as extended projections. Top panels show movie sequences. Bottom panels show kymographs generated along the respective red lines. The place in the time sequence is indicated by the red line moving along the kymographs.
