Mechanical Properties Measured by Atomic Force Microscopy Help Evaluate Different Constructions of Re-engineered...

Area of Science:

• Immunology
• Biophysics
• Cancer Biology

Background:

• Chimeric antigen receptor-T (CAR-T) cell therapy has revolutionized hematological cancer treatment but faces challenges in solid tumors, including toxicity and limited persistence.
• The role of cellular mechanics and biophysical properties in CAR-T cell function is largely unexplored, representing a critical knowledge gap.

Purpose of the Study:

• To investigate the impact of different CAR designs, including single- and dual-target CARs, on CAR-T cell efficacy against CD19 and/or CD123 expressing cancers.
• To explore the relationship between CAR-T cell biophysical properties, specifically binding forces, and their therapeutic outcomes in vitro and in vivo.
• To elucidate the role of cellular mechanics in CAR-T cell function and identify design principles for improved CAR-T therapies.

Main Methods:

• Development and testing of various CAR molecules targeting CD19 and/or CD123.
• In vitro assessment of CAR-T cell cytotoxicity against relevant cancer cell lines.
• In vivo evaluation of CAR-T cell efficacy in preclinical mouse models.
• Utilizing atomic force microscopy (AFM) to quantify the binding forces between CAR-T cells and target antigens.

Main Results:

• Single-specific CAR-T cells targeting CD19 or CD123 demonstrated potent in vitro cytotoxicity.
• Dual-target CAR-T cells, particularly those arranged in parallel or series configurations, exhibited optimal in vivo efficacy.
• A negative correlation was observed between CAR-T cell-antigen binding forces and therapeutic efficacy in vivo, suggesting lower binding forces enhance killing efficiency.
• Lower binding forces were associated with faster CAR-T cell action and detachment, leading to improved tumor cell killing.

Conclusions:

• Cellular mechanics, specifically binding forces, are critical determinants of CAR-T cell therapy efficacy.
• Optimizing CAR-T cell binding forces through rational design can enhance therapeutic outcomes, potentially overcoming limitations in solid tumors.
• This study provides novel insights into the biophysical underpinnings of CAR-T cell function, guiding future development of more effective CAR-T therapies.