Morphodynamics of T-lymphocytes: Scanning to spreading

Area of Science:

• Immunology
• Biophysics
• Cell Biology

Background:

• Adaptive immune recognition begins with T cell receptor (TCR) complex binding to ligands, triggering molecular rearrangements and cell shape changes.
• While initial studies focused on immobilized ligands, recent research highlights the critical role of ligand mobility and substrate mechanics in T cell activation and TCR clustering.

Purpose of the Study:

• To review experimental findings on T cell interactions with artificial antigen-presenting cells.
• To investigate the impact of environmental mechanics on T cell adhesion and actin morphodynamics.
• To reconcile differing experimental observations regarding ligand mobility and T cell activation.

Main Methods:

• Review of experiments involving T cells interacting with planar artificial antigen-presenting cells.
• Analysis of T cell adhesion and actin morphodynamics under varying mechanical conditions.
• Interpretation of experimental results using a mechanical model of cell morphodynamics.

Main Results:

• A sequence of events from initial contact to the final spread state of T cells has been elucidated.
• The biophysical properties of the environment, including substrate compliance and ligand mobility, significantly influence T cell spreading and actin dynamics.
• Experimental data aligns with a mechanical model that describes various morphodynamic states during T cell-APC interaction.

Conclusions:

• Environmental mechanics play a crucial role in regulating T cell adhesion, actin remodeling, and overall cell spreading during immune recognition.
• Understanding these mechanical influences is key to reconciling previous findings and advancing our knowledge of T cell activation.
• A unified mechanical model can effectively capture the complex morphodynamic changes observed in T cell-antigen-presenting cell interactions.