T cell morphodynamics reveal periodic shape oscillations in 3D migration

TL;DR

This study quantitatively characterizes the 3D shape dynamics of T cells during migration, revealing periodic oscillations and stereotyped motifs that underpin their movement in complex environments.

Contribution

We developed a novel shape descriptor and analysis framework to uncover the low-dimensional morphodynamics and oscillatory behaviors of T cells in 3D migration.

Findings

T cells exhibit low-dimensional shape space.

Migration modes include run-and-stop with ~150 s cycles.

Periodic shape oscillations occur every ~100 s during run mode.

Abstract

T cells use sophisticated shape dynamics (morphodynamics) to migrate towards and neutralise infected and cancerous cells. However, there is limited quantitative understanding of the migration process in 3D extracellular matrices (ECMs) and across timescales. Here, we leveraged recent advances in lattice light-sheet microscopy to quantitatively explore the 3D morphodynamics of migrating T cells at high spatiotemporal resolution. We first developed a new shape descriptor based on spherical harmonics, incorporating key polarisation information of the uropod. We found that the shape space of T cells is low-dimensional. At the behavioural level, run-and-stop migration modes emerge at ~150 s, and we mapped the morphodynamic composition of each mode using multiscale wavelet analysis, finding 'stereotyped' motifs. Focusing on the run mode, we found morphodynamics oscillating periodically (every ~100 s) that can be broken down into a biphasic process: front-widening with retraction of the uropod, followed by a rearward surface motion and forward extension, where intercalation with the ECM in both of these steps likely facilitates forward motion. Further application of these methods may enable the comparison of T cell migration across different conditions (e.g. differentiation, activation, tissues, and drug treatments), and improve the precision of immunotherapeutic development.