Hyperstabilization of T cell microvilli contacts by chimeric antigen receptors

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• T cells (T lymphocytes) use membrane microvilli (MV) to scan for ligands via T cell receptors (TCRs).
• Chimeric antigen receptors (CARs) are engineered receptors with potential therapeutic applications, often exhibiting higher affinity than natural TCRs.
• Understanding the relationship between CAR design, microvillar dynamics, and T cell function is crucial for optimizing immunotherapy.

Purpose of the Study:

• To investigate how variations in CAR design affect microvillar dynamics and T cell function.
• To explore the interplay between receptor affinity, antigen presentation, and T cell synapse formation.
• To provide insights for designing more effective CAR-based immunotherapies.

Main Methods:

• High-resolution lattice light-sheet (LLS) and total internal reflection fluorescence (TIRF) imaging were employed.
• Microvillar scanning dynamics were visualized in T cells engineered with different CAR designs.
• The impact of receptor affinity, antigen density, and binding site multiplicity on cellular behavior was assessed.

Main Results:

• Conventional CARs, compared to TCRs, were found to hyper-stabilize microvillar contacts.
• Reducing CAR affinity, antigen density, or the multiplicity of binding sites normalized microvillar dynamics.
• Synapse resolution and T cell effector functions were enhanced with decreased affinity and/or antigen density.

Conclusions:

• CAR design significantly influences T cell microvillar dynamics and synapse formation.
• Optimizing CARs for immunotherapy may involve tuning receptor affinity and antigen engagement parameters.
• Balancing receptor properties with underlying T cell biology is key for effective CAR-based therapies.