Deterministic actin waves as generators of cell polarization cues

Significance
Dendritic cells are immune cells that migrate within the human body in search of pathogens. This search is performed by a random walk, which combines persistent and diffuse movements. The mechanism underlying this random walk is currently not known. We analyzed very long trajectories of dendritic cells ex vivo, and we describe here their characteristic persistent and diffusive patterns. Together with theoretical analysis, we provide evidence that the random walk of dendritic cells could be a consequence of the intrinsic actin dynamics without need for molecular noise or external polarization cues. Our results hint at the possibility that these cells can adapt their random search strategies by changing the spontaneous dynamics of their actin cytoskeleton.