Engineered Meganucleases for Stable TTR Gene Disruption
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Solution Overview
Problem
Current treatments for transthyretin amyloidosis, such as liver transplantation and CRISPR/Cas9 gene editing, are invasive, costly, and not effective for all forms of the disease, highlighting the need for alternative therapies that can stably reduce transthyretin levels.
Innovation Solution
Engineered meganucleases are developed to recognize and cleave specific sequences in the transthyretin gene, using recombinant adenoviruses or lipid nanoparticles to deliver the meganucleases, which induce targeted DNA breaks and promote non-homologous end-joining for stable reduction of transthyretin levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liver transplantation is used to treat transthyretin amyloidosis, then transthyretin levels are reduced, but the treatment is invasive, costly, and requires long-term immunosuppressive therapy
Solution Approach 1:
The patent replaces the mechanical surgical intervention of liver transplantation with a molecular/biochemical approach using engineered meganucleases. The meganucleases are delivered via non-invasive methods (lipid nanoparticles or recombinant adenoviruses) to selectively cleave and destroy the transthyretin gene in hepatocytes, achieving gene therapy without surgery. This substitution eliminates the need for invasive surgery, organ donation, and long-term immunosuppressive therapy while maintaining the ability to reduce transthyretin levels.
2Reliability
If CRISPR/Cas9 gene editing is used, then transthyretin levels are reduced, but the treatment is costly and not effective for all forms of the disease
Solution Approach 1:
The patent applies local quality by designing meganucleases with highly specific recognition sequences tailored to different transthyretin gene variants. Each meganuclease is engineered to target a specific disease-associated mutation (e.g., V30M for familial amyloid polyneuropathy, or wild-type sequences for senile systemic amyloidosis) through customized hypervariable regions. This allows the same general platform to address multiple disease forms by simply changing the recognition sequence, making the treatment adaptable to different patient needs without requiring different fundamental mechanisms.
3Reliability
If engineered meganucleases are used to treat transthyretin amyloidosis, then transthyretin levels are stably reduced, but the treatment must be delivered through invasive vectors
Solution Approach 1:
The patent employs two intermediary delivery systems that bridge the gap between the engineered meganucleases and the target hepatocytes: lipid nanoparticles and recombinant adenoviruses. These intermediaries package and transport the meganucleases into liver cells in a protected manner, overcoming the challenge of delivering large protein molecules to specific cell types. The lipid nanoparticles provide a non-invasive intravenous delivery route, while recombinant adenoviruses offer targeted hepatic transduction, both serving as effective mediators that enable stable gene editing without requiring direct surgical intervention.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The engineered meganucleases effectively reduce transthyretin levels, offering a less invasive and potentially more widespread therapeutic option for transthyretin amyloidosis, including forms not addressed by existing treatments.
Implementation Method 1
an engineered meganuclease that recognizes and binds to a specific sequence in a transthyretin gene
Implementation Method 2
the engineered meganuclease produces a cleavage site in the chromosome at a recognition sequence
Implementation Method 3
the target sequence is disrupted by non-homologous end-joining and introduction of an insertion or deletion at said cleavage site
Data Source
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AI summary
The present invention encompasses engineered meganucleases that bind and cleave a recognition sequence within a TTR gene. The present invention also encompasses methods of using such engineered meganucleases to make genetically-modified cells. Further, the invention encompasses pharmaceutical compositions comprising engineered meganuclease proteins, or nucleic acids encoding engineered meganucleases of the invention, and the use of such compositions for treatment of TTR-associated diseases, such as transthyretin amyloidosis.