Tunable gene control via RNA splicing with a clinically approved small molecule

Area of Science:

• Biotechnology
• Molecular Biology
• Gene Therapy

Background:

• Precise control of transgene expression is essential for safe and effective gene and cell therapies.
• Existing inducible systems often face challenges with immunogenicity and lack of clinical approval for inducers, limiting their therapeutic application.

Purpose of the Study:

• To develop a novel, clinically relevant inducible transgene expression system.
• To leverage a clinically approved oral drug for precise and reversible transgene regulation.

Main Methods:

• Developed RisdiON, a compact inducible system utilizing risdiplam-responsive elements and a split-ATG architecture.
• Tested RisdiON in cell lines, induced pluripotent stem cells (hiPSCs), and primary T cells for transgene control, CAR expression, and Cas9 gene editing.
• Demonstrated in vivo transgene expression using adeno-associated virus (AAV) delivery and assessed reversibility.

Main Results:

• RisdiON provides robust, dose-dependent, and titratable transgene induction with minimal leakiness.
• The system successfully controlled various transgenes, enabled inducible CAR expression in T cells, and regulated Cas9 for gene editing.
• Achieved reversible transgene expression in vivo, highlighting the platform's potential for therapeutic applications.

Conclusions:

• RisdiON offers a safe, modular, and clinically translatable inducible system for next-generation gene and cell therapies.
• The use of an orally bioavailable drug (risdiplam) enhances the therapeutic potential and patient compliance.
• This platform provides precise, reversible transgene control, overcoming limitations of current inducible systems.