Wetting, speed, and contact geometry in cell-cell collisions*

Collective cell migration, in which cells crawl in coordination, is crucial in many biological processes. The extent of collective migration is controlled by how cells interact, which is often studied in cell pairs. A recent study observed head-on collisions between trains of MDCK cells in narrow confinement [1]. One feature controlling the outcome was contact geometry—the leading cell that formed a smaller contact angle with the substrate had a larger probability of maintaining its polarity. We build a phase-field model for two-body collisions, in which cells are treated as continuously deformable objects. We hypothesize that cells can sense their velocity and align to it over a finite timescale. We control the cell’s contact angle via its strength of adhesion to the substrate, surface tension, and strength of active force in the leading edge and track its contact angle and speed. Within this model, we show that contact angle does predict collision outcome, but that this is potentially misleading as contact angle correlates with cell speed, which is a better predictor of whether a cell remains persistent upon collision.

[1] Jain, Cachoux, Narayana, et. al, Nature Physics 2020