Figure 4
From: Mechanosensitive traction force generation is regulated by the neutrophil activation state
RMS tractions and traction maxima of neutrophils from healthy donors after stimulation by LPS, IFN-\(\gamma\), and GM-CSF. Mean (and SEM) of root-mean-square tractions (\(T_{RMS}\)), traction maxima (\(T_{Max}\)), and displacements of neutrophils from healthy donors seeded on 1.5 kPa polyacrylamide gels. Cells were allowed to attach and settle and then imaged before stimulation (“Unstim.”). Cells were then treated with either: (a–c) 100 ng/ml lipopolysaccharide (“LPS”, n = 34)); (d–f) a cytokine cocktail of 100 μg/ml IFN-\(\gamma\) and 100 ng/ml GM-CSF (“Cyto”, n = 63); or (g–i) a combined cocktail of LPS, IFN-\(\gamma\), and GM-CSF (“L+C”, n = 34). Cells were imaged 30 min post-addition. Displacements were computed in Matlab by T-PT, and displacement heatmaps were generated for three representative cells at 30 min (c,f,i). Tractions were computed using the finite element method in Abaqus. Scale bars are 10 μm, and the white contours represents the boundary of the cell edge. *p < 0.05 (paired Student’s t-test).
