High-Throughput Centrifuge Force Microscopy Reveals Dynamic Immune-Cell Avidity at the Single-Cell Level

Area of Science:

• Immunology
• Biophysics
• Cellular Mechanics

Background:

• Cell-cell binding is crucial for immune responses like surveillance and T-cell activation.
• Existing methods for measuring cell avidity lack throughput or precision.
• Bispecific T-cell Engagers (BiTEs) are novel immunotherapies enhancing immune cell targeting of cancer.

Purpose of the Study:

• To develop a high-throughput, quantitative method for measuring cell binding lifetimes and strength.
• To investigate immune cell interactions mediated by BiTE molecules using this new method.

Main Methods:

• Development of a next-generation centrifuge force microscope (CFM) with multichannel fluorescence imaging.
• Utilizing CFM for high-throughput, live monitoring of single-cell interactions under force.
• Performing cell-protein binding and cell-cell avidity assays.

Main Results:

• Quantified T- and B-cell unbinding from BiTE-functionalized surfaces, showing ligand concentration-dependent binding strength.
• Demonstrated a strong, time-dependent increase in BiTE-mediated immune cell avidity in cell-cell assays.
• Revealed receptor-specific relationships in immune cell binding dynamics.

Conclusions:

• The CFM provides high-throughput, quantitative single-cell force analysis of immunological interactions.
• This technology offers new insights into the dynamics of immune cell binding under force.
• The findings have broad implications for immunotherapy development and understanding cellular mechanics.