Interstitial motility of Kindlin-3–deficient T cells inside lymph nodes is severely impaired. (A) Interstitial motility of extravasating wt and Kindlin-3–deficient T cells inside inflamed popliteal lymph nodes measured 4 hours after adoptive transfer. Cell trajectories were determined at 36-second intervals, as detailed in “Materials and methods.” Three-dimensional paths tracking T-cell movement are depicted as if emanating from a common starting point. (B) Scatterplots illustrating the mean velocities and displacement rates of the individual T-cell tracks as depicted in panel A (n = 75 for k3-null; n = 48 for wt). Both parameters were significantly (P < .0001) lower for Kindlin-3–deficient T cells (one experiment representative of 3 experiments is shown). (C) LFA-1 adhesiveness to ICAM-1– or VCAM-1–coated beads (each containing 4200 CAM sites/μm²) on wt and Kindlin-3–deficient effector T cells migrating over CXCL9, determined under shear-free conditions. The frequencies of T-cell collisions with productive short-lived (≤180 seconds) and long-lived (≥190 seconds) contacts are depicted for each group and are expressed as a percentage of all lymphocyte bead collision events. No stable contacts to ICAM-1 or VCAM-1 beads could be observed in the absence of cations. Values are for >90 cells in 5 fields of view. One experiment representative of 3 experiments is shown. The mean contact duration is depicted in parentheses. The distribution of all T-cell bead contact durations is depicted in supplemental Figure 6. Further details are provided in “Materials and methods.”