Integrative experimental/computational approach establishes active cellular protrusion as the primary driving force of phagocytic spreading by immune cells
Fig 5
Predictions of the protrusive zipper model in the absence of adhesion stress.
(A) For purely protrusion-driven spreading, lamellar pseudopods form as the protrusion stress increases over time. Time stamps of the the shown sample shapes are included. (B) Contact area increases sigmoidally over time for the protrusive zipper model, in good agreement with our measurements of the time course of the mean contact area on the highest density of IgG. Filled circles indicate where the shapes shown in panel A were computed. (C) Protrusion stress (governed by Eq (11)) and cortical tension (governed by Eq (1)) increase during cell spreading. (D) Varying the parameter s0 determines the thickness of the leading lamella, resulting in a thin pseudopod for s0 = 0.4 μm (top) and coordinated global cell deformation for s0 = 2.0 μm (bottom). The sample shapes are shown at 120 s. All other protrusive zipper simulations in this paper were carried out using s0 = 0.8 μm.