Fig. 5.

Comparison of the stochastic and deterministic models of cell rolling at low (A) and high (B–D) P-selectin site densities. Average translational velocities of modeled PMNs, decorated with deformable microvilli, rolling over surfaces coated with P-selectin at a site density of 15 (A) or 150 (B) molecules/μm² were computed for a membrane stiffness value of 3 dyn/cm. Average translational velocities (C) and numbers of bonds (D) for cells decorated with either rigid or deformable microvilli rolling over P-selectin-coated substrates (150 molecules/μm²) were computed using the deterministic model for a membrane stiffness value of 3 dyn/cm. In all these calculations, receptor-ligand kinetics was governed by the Dembo model. Data from the stochastic model represent means ± SE from 3 independent simulations.