T Cells Tear Apart Confining Extracellular Matrix Via a Breaststroke-like Motion to Generate Migration Paths.

Area of Science:

• Immunology
• Biophysics
• Cell Biology

Background:

• T cells are crucial for immunity, migrating through tissues to target abnormal cells.
• Understanding T cell pathfinding in confined, nanoporous environments like the extracellular matrix (ECM) is vital for studying diseases such as fibrosis and cancer.
• Current models often lack insights into how T cells navigate and create paths in dense matrices.

Purpose of the Study:

• To investigate the mechanisms by which T cells migrate and create paths within confining, nanoporous extracellular matrices.
• To determine the key mechanical properties of the ECM that govern T cell migration.

Main Methods:

• Studied T cell migration in collagen-rich matrices with varying stiffness, viscoelasticity, plasticity, and shear strength.
• Utilized advanced microscopy and mechanical testing to analyze T cell behavior and matrix interactions.

Main Results:

• T cell migration correlated significantly with the shear strength of the ECM, not its stiffness or viscoelasticity.
• T cells extend actin-rich protrusions that engage in a breaststroke-like motion to actively break down the matrix.
• This matrix-tearing mechanism allows T cells to generate their own migration paths.

Conclusions:

• T cell migration through confining matrices is primarily dictated by the matrix's shear strength.
• T cells employ a novel mechanical strategy, involving matrix disruption via a breaststroke-like motion, to navigate dense environments.
• This finding offers new perspectives on immune cell dynamics in pathological conditions and tissue engineering.