Figure 3. F-actin and membrane bending contribute to TCR force generation.

a Representative microscope images showing the spreading and tension signals of T cells treated with cytoskeleton inhibitors. b Bar graph quantifying the tension decreases when T cell were treated with cytoskeleton drugs. n>120 cells for each group from three independent experiments. Error bar indicates SEM. ns, not significant P=0.4188, ***P = 0.0001, ****P < 0.0001 c Schematic showing the recruitment of F-actin to TCR engagement sites with the aid of adaptor proteins. d Representative images showing the tension signal of T cells with and without AX-024 treatment. e Bar graph quantifying the tension signal decrease when the T cells were treated with AX-024. f Schematic showing that elongating DNA hairpin increases the maximum antigen height, which decreases the membrane bending and the strain transmitted to TCR-pMHC bonds. g Representative images showing TCR tension signals under different antigen heights. h-i Dot plot quantifying intensities of TCR tension (h) and pYZap70 (i) of T cells engaging antigens with different heights. At least 200 cells from three independent experiments were analyzed. Lines indicate the mean. Scale bars = 5 μm.