Regulatable In Vivo Gene Expression via Adaptamers.

Area of Science:

• Biotechnology
• Molecular Biology
• Gene Therapy

Background:

• Current inducible gene expression systems for gene therapy face challenges like large size, short induction duration, and immunogenic regulators, hindering in vivo application.
• Achieving precise, reversible control of transgene expression is critical for the safety and efficacy of gene therapies.

Purpose of the Study:

• To develop a novel, compact RNA switch for precise and reversible control of transgene expression.
• To create a clinically compatible system for tunable gene therapies using endogenous RNA editing.

Main Methods:

• Designed a compact RNA switch (<120 bp) termed adaptamer, integrating a small-molecule-responsive aptamer with ADAR-mediated RNA editing.
• Demonstrated the adaptamer's functionality in various cell lines, including human T-cells.
• Utilized adeno-associated virus (AAV) delivery in mice to control FGF21 expression via the adaptamer system.

Main Results:

• The adaptamer system enables precise, small-molecule-dependent modulation of protein translation via a post-transcriptional mechanism.
• Adaptamers showed high functionality across multiple cell lines, including human T-cells.
• In vivo, AAV-delivered adaptamer-controlled FGF21 expression led to significant metabolic remodeling, increased energy expenditure, and obesity reversal in mice.

Conclusions:

• The adaptamer represents a minimal, programmable RNA switch for tunable genetic medicines.
• This system offers a clinically compatible approach for the safe deployment of pleiotropic and dose-limited proteins in gene therapy.