Primary Cell Gene Editing With Nonviral Circular DNA Templates
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Solution Overview
Problem
Existing methods for gene editing in primary human cells, particularly T cells, face challenges such as high toxicity, low efficiency, and limitations in making large edits, which hinder therapeutic applications.
Innovation Solution
A method using circular polynucleotides with specific nucleotide sequences oriented for homologous recombination at the endogenous genomic target locus, integrated without viral-mediated delivery, and accompanied by nuclease compositions to facilitate gene editing, enabling expression of functional proteins like TCRs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If AAV is used to deliver homology repair template DNA, then gene targeting efficiency is improved, but production time increases, cost increases, and regulatory difficulty increases
Solution Approach 1:
The patent extracts the essential function of AAV (delivering homology repair template DNA) and separates it from the AAV vector itself. Instead of using AAV to deliver DNA, the patent uses naked plasmid DNA directly, removing the viral delivery system while retaining the gene delivery function. This eliminates AAV production time and cost while maintaining gene targeting capability.
Solution Approach 2:
The patent replaces the expensive, complex AAV vector system with inexpensive naked plasmid DNA that can be easily prepared and delivered. The plasmid DNA serves as a disposable, simple delivery vehicle that accomplishes the same function without the regulatory and production burdens of viral vectors.
2Ease of manufacture
If naked plasmid DNA is used for gene editing, then production cost decreases, but cell toxicity increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the DNA delivery system by using highly purified plasmid DNA with specific purity specifications (e.g., A260/A280 ratio > 1.8, endotoxin levels < 0.1 EU/µg). This parameter optimization reduces cellular toxicity while maintaining the cost advantages of naked plasmid DNA.
Solution Approach 2:
The patent uses inexpensive naked plasmid DNA as a disposable delivery vehicle, but implements rigorous purification protocols to remove toxic contaminants. The purified DNA accomplishes gene delivery without the cellular toxicity associated with crude plasmid preparations.
3Ease of operation
If DNA delivery is performed with standard vectors, then ease of delivery is improved, but DNA size optimization is insufficient, limiting delivery efficiency
Solution Approach 1:
The patent optimizes the DNA vector parameters by designing plasmids with specific size ranges (e.g., 3-10 kb), optimized GC content, and minimized secondary structures. These parameter optimizations enhance delivery efficiency through electroporation and other physical delivery methods while maintaining ease of construction.
Solution Approach 2:
The patent segments the homology repair template into modular plasmid components that can be independently optimized and assembled. This segmentation allows for size optimization of each module while maintaining the overall functionality of the gene targeting system.
4Ease of manufacture
If kit-based plasmid preparation is used, then ease of preparation is improved, but DNA impurities increase, contributing to cellular toxicity
Solution Approach 1:
The patent implements stringent DNA purification parameter specifications, including A260/A280 ratios > 1.8, A260/A230 ratios > 2.0, and endotoxin levels < 0.1 EU/µg. These parameter changes ensure high purity DNA that is easy to prepare using standardized protocols but free from toxic contaminants.
Solution Approach 2:
The patent uses inexpensive, disposable purification columns and reagents to achieve high-purity DNA preparations. The simple, single-use purification system removes toxic impurities without requiring complex, expensive equipment while maintaining ease of preparation.
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
This approach enhances gene editing efficiency and viability in primary cells by avoiding viral toxicity and enabling larger edits, potentially expanding therapeutic applications.
Implementation Method 1
Gene targeting relies on homologous recombination after delivery of a homology repair template DNA bearing the desired altered sequence, along with a site-specific nuclease targeting the locus of interest
Data Source
AI summary
Methods and compositions are provided for nuclease-mediated gene editing of primary cells without the use of viral mediated delivery. Methods of treatments using edited primary cells are also provided.