Fig. 4

The morphological changes in CD4⁺ T cells were dependent on the F-actin cytoskeleton. a The accumulation of F-actin (blue) in an elongated-flattened CD4⁺ T cell (top line) or a round-flattened CD4⁺ T cell (middle line) after IS formation. The distribution of F-actin in a CD4⁺ T cell after it made contact with an OVA_323-339-pulsed DC in the presence of cytochalasin D is also depicted. TCR (red) and ICAM-1 (green) were labelled to show the IS formation. The dotted white line depicts the contact boundary between the CD4⁺ T cells and the DCs. Scale bar = 2 μm. b The MFIs of F-actin in the IS of the round-flattened T cells and the elongated-flattened T cells (mean ± s.e.m., n=25, three independent experiments), ***P<0.001 (two-tailed Student’s t-test). c Comparison of the contact area of T cell-DC contact based on the area of accumulation of F-actin in the IS (mean ± s.e.m., n=25, three independent experiments), ***P<0.001 (two-tailed Student’s t-test). d The percentage of elongated and/or flattened CD4⁺ T cells was analysed after T cells made contact with DCs with cytochalasin D, nocodazole, TG, or cytochalasin D and TG treatment (mean ± s.e.m., n=50, three independent experiments). e The percentage of elongated and/or flattened CD4⁺ T cells after IS formation with 1 μM, 2.5 μM, 5 μM, or 10 μM cytochalasin D treatment (mean ± s.e.m., n=50, three independent experiments)