Chemotaxis of branched cells in complex environments

TL;DR

This study models how branched cells, like neutrophils, navigate complex environments using chemotaxis, revealing a speed-accuracy tradeoff and validating predictions with experimental data.

Contribution

It introduces a theoretical model of branched-cell chemotaxis in complex geometries, linking cell speed to navigation accuracy, and compares it with experimental observations.

Findings

Slow cells are more accurate in chemotaxis.

Neutrophils behave as fast cells, sacrificing accuracy.

Model captures sub-cellular and large-scale migration details.

Abstract

Cell migration in vivo is often guided by chemical signals. Such chemotaxis, such as performed by immune cells migrating to a wound site, is complicated by the complex geometry inside living tissues. In this study, we extend our theoretical model of branched-cell migration on a network by introducing chemokine sources to explore the cellular response. The model predicts a speed-accuracy tradeoff, whereby slow cells are significantly more accurate and able to follow efficiently a weak chemoattractant signal. We then compare the model's predictions with experimental observations of neutrophils migrating to the site of laser-inflicted wound in a zebrafish larva fin, and migrating in-vitro inside a regular lattice of pillars. We find that the model captures the details of the sub-cellular response to the chemokine gradient, as well as the large-scale migration response. This comparison suggests that the neutrophils behave as fast cells, compromising their chemotaxis accuracy, which explains the functionality of these immune cells.