Extended Data Fig. 5: Dependence of immune cell migration and force generation on matrix stiffness and pore size.
From: Dynamic traction force measurements of migrating immune cells in 3D biopolymer matrices
Cell contractility (a, e), matrix deformations (b, f), cell speed (c, g), and cell travelled distance (d, h) are measured in collagen gels (0.6 mg/ml, 1.2 mg/ml, and 2.4 mg/ml from different collagen batches) with different stiffnesses (a-d) and pore sizes (e-h). The storage modulus of different collagen gels is measured with a cone-plate shear-rheometer at 0.02 Hz (1% strain amplitude, see Extended Data Fig. 3), and the pore size is derived from confocal reflection images(see Extended Data Fig. 4). Colored bars and error bars indicate mean }se for n individual cells (black points) from three (pink and orange bars) or four (green and blue bars) independent experiments. * indicates p<0.05 and ** indicates p<0.01 for two-sided t-test with Bonferroni correction51. For clarity, the legend, data points, statistical tests, and cell numbers are only shown in the top row. (a, e), Maximum contractility of each cell during a 23 min measurement period. (b, f), Maximum of the absolute matrix deformation vector (99% percentile) of each cell during a 23 min measurement period. (c, g), Mean cell speed during a 23 min measurement period. (d, h), Migration distance of cells after 23 min in 1.2 mg/ml collagen gels. Distance is calculated as the diagonal of the smallest rectangle containing the cell trajectory. Here, only trajectories containing at least 20 data points (corresponding to trajectories of at least 19 min duration) are included in the analysis. Cell contractility monotonically increases, and matrix deformation monotonically decreases with matrix stiffness. Migration speed and travelled distance show a maximum response at intermediate pore sizes.
