Figure 7. Effect of lfa clustering on lfa1 and icam1 re-binding events.

The cumulative number of (A) lfa1 re-binding events and (B) icam1 re-binding events were counted at 50 simulation cycle intervals (5 seconds) for each leukocyte. A lfa1 (or icam1) rebinding event was defined as a bond formation event by a lfa1 (or icam1) object that had already participated in a bond formation event in a previous time step. Averages are plotted for 30 leukocytes per experimental condition (with or without LFA1Clustering). Simulation data with LFA1Clustering were from leukocytes that sustained adhesion (rolling followed by at least 30 simulation cycles of arrest until the end of the simulation). Simulation data without LFA1Clustering were from leukocytes that exhibited initial and transient adhesion (at least 300 simulation cycles of arrest). Without LFA1Clustering, the average adhesion time was 39.8±7.2 seconds before the leukocyte initiated rolling again (average time = 43.9±7.1 seconds). Error bars: ± SD.