Figure 1.

In vitro Dynamics of T Lymphocyte Recruitment (A) Video micrograph of Jurkat T cells interacting with immobilized CXCL12/ICAM-1 in shear flow. Cells were perfused into parallel plate flow chambers at a shear rate of 100 s⁻¹ (right to left). Trajectories for eight individual cells that ultimately arrested were reconstructed from video analysis. (B) Three characteristic velocity-distance profiles for cells that tethered, rolled, and arrested within the frame of view (red). The trajectory of a non-adherent cell is shown for comparison (gray). (C) Instantaneous velocity distribution for one individual cell prior to arrest. The macroscopic rolling velocity, v_roll, is given by the mean of the distribution. (D) Population-level distribution of mean rolling velocities indicated significant heterogeneity among cells. In both (C) and (D), velocities varied according a gamma distribution (blue line), consistent with theory [18]. (E) Velocity-distance profiles from all cell trajectories were synchronized to the moment of tether formation to identify the range of arrest distances. The population average velocity as a function of distance is indicated (red).