Engineering a Dual Small Molecule Gated ZAP70 Switch in T Cells

Area of Science:

• Immunology
• Molecular Biology
• Biotechnology

Background:

• T cell-based cancer therapies hold promise but require safety mechanisms to control T cell overactivity.
• Existing methods for regulating T cell activity lack precise control and temporal responsiveness.

Purpose of the Study:

• To engineer and characterize a novel dual small molecule-gated ZAP70 signaling switch for precise T cell activity regulation.
• To assess the switch's ability to control early T cell signaling events and downstream responses.

Main Methods:

• Engineered a ZAP70 allele fused to an engineered estrogen receptor ligand-binding domain (ERT2).
• Utilized 4-hydroxy-tamoxifen to upregulate and 3-MB-PP1 to downregulate ZAP70 activity.
• Assessed T cell signaling modulation via CD69, calcium levels, and cytokine release.

Main Results:

• Demonstrated dual small molecule-gated control of ZAP70 activity, enabling both upregulation and downregulation of T cell signaling.
• Showcased temporal control of early T cell signaling on the minute timescale by adjusting activator and inhibitor concentrations.
• Observed modulation of CD69 and intracellular calcium levels, but limited control over downstream cytokine release.

Conclusions:

• The developed ZAP70 signaling switch provides a novel mechanism for precise, temporally controlled regulation of T cell activity.
• While effective for early signaling events, further research is needed to optimize control over downstream cytokine production for clinical applications in adoptive T cell therapy.