In silico phase-field modeling of cell directed migration towards environments of lower or higher adhesion

This work focuses on the modeling of adhesive haptotaxis in cell migration. On substrates with varying adhesiveness, cells typically move towards areas of strong adhesion. However, experiments conducted on lymphocytes at the Adhesion & Inflammation Laboratory (LAI) in Marseilles have revealed an opposite behaviour called reverse adhesive haptotaxis. A model for single cell adhesive migration has been proposed by the group of Aronson and Ziebert (Ziebert et al. 2013, Löber et al. 2014, Ziebert et al. 2011) which takes into account the dynamic of adhesion site density. We adapt the model from Ziebert et al. 2013 and investigate the impact of adhesion on both propulsion of the cell (a coupling already proposed in Ziebert et al. 2013) and the strength of actin polymerization inside the cell (a novelty of this paper). This adapted model exhibits classical haptotaxis through the coupling on propulsion and reverse haptotaxis through the coupling on polymerization. We also investigate thoroughly the synergy between these two mechanisms. The presence of these two behaviours makes this extension potentially relevant for lymphocytes.