A Small-Molecule-Responsive Riboswitch Enables Conditional Induction of Viral Vector-Mediated Gene Expression in Mice

Area of Science:

• Biotechnology
• Molecular Biology
• Gene Therapy

Background:

• Adeno-associated viral (AAV) vector gene therapy offers significant medical potential but requires controllable therapeutic protein expression for safety and patient-centric care.
• Current methods using protein-based systems face limitations like immunogenicity and coding capacity, while existing ligand-dependent riboswitches show moderate efficacy, especially ON-switches.

Purpose of the Study:

• To evaluate the efficacy of the tetracycline-dependent ribozyme K19 for controlling AAV-mediated transgene expression in vivo.
• To demonstrate key features for clinical gene therapy, including multiorgan functionality, potent regulation, reversibility, and fine-tuning of expression.

Main Methods:

• Utilized the K19 ribozyme to control AAV-mediated transgene expression in a mouse model.
• Systematically assessed ligand and reporter protein plasma levels to characterize pharmacokinetic-pharmacodynamic relationships.

Main Results:

• Provided the first proof-of-concept for using the K19 ribozyme in AAV gene therapy.
• Achieved potent regulation (up to 15-fold induction), reversibility, and repeated induction of transgene expression.
• Established pharmacokinetic-pharmacodynamic relationships for ligand and reporter protein levels.

Conclusions:

• The K19 ribozyme is a feasible tool for controllable AAV-mediated gene expression.
• This approach supports the development of engineered riboswitches for clinical gene therapy applications.
• Demonstrated key features essential for patient-centric and safe gene therapy interventions.