Degron-based bioPROTACs for controlling signaling in CAR T cells

Area of Science:

• Immunology and Molecular Biology: Focuses on cellular engineering and protein degradation mechanisms for advanced immunotherapy.

Background:

• Chimeric antigen receptor (CAR) T cell therapy shows promise but faces challenges with potent signaling impacting safety and efficacy.
• Current methods for regulating CAR signaling often rely on systemic small molecule degradation, lacking precise control.
• Genetic circuits offer autonomous, cell-by-cell regulation, presenting a more refined approach to controlling CAR activity.

Approach:

• Developed novel bioPROTACs, heterobifunctional proteins that link target recognition domains with ubiquitin proteasome system recruiters.
• Utilized a compact four-residue degron and demonstrated degradation of both cytosolic and membrane proteins using nanobodies or synthetic leucine zippers.
• Engineered a genetic circuit to degrade the tyrosine kinase ZAP70 specifically upon recognition of a target antigen, disrupting CAR T cell signaling conditionally.

Key Points:

• Demonstrated potent degradation of CARs and inhibition of CAR T cell signaling in primary human T cells using bioPROTACs.
• Successfully engineered a genetic circuit for antigen-specific, conditional degradation of ZAP70, thereby controlling CAR T cell activity.
• BioPROTACs offer a programmable protein degradation tool for precise, cell-autonomous regulation of CAR signaling.

Conclusions:

• BioPROTACs provide a powerful new tool for enhancing the safety and efficacy of CAR T cell therapies.
• This technology enables sophisticated cell engineering strategies for fine-tuning CAR T cell responses in a targeted manner.
• The development expands the toolbox for engineering CAR T cells, paving the way for more controlled and effective immunotherapies.