Primed CAR-T Cells via Non-Viral Large DNA Insertion
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Solution Overview
Problem
Current CAR-T cell immunotherapy faces challenges such as off-target toxicity due to engagement with normal cells expressing low levels of target antigens and difficulties in inserting large gene constructs using viral vectors, which limits the effectiveness and safety of immune cell engineering.
Innovation Solution
Non-viral insertion of DNA templates greater than or equal to 5 kilobase pairs into the genome of primary immune cells, specifically using a ribonucleoprotein complex with a nuclease domain and guide RNA to target and insert a chimeric antigen receptor and priming receptor, avoiding viral vectors and reducing off-target risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If viral vectors are used to insert large gene constructs into immune cells, then the gene insertion capability is improved, but the safety and off-target risks worsen
Solution Approach 1:
The system divides the gene delivery process into two independent parts: (1) a viral vector that delivers only the minimal necessary genetic elements (such as a small activating RNA and a selectable marker), and (2) a separate large DNA construct (such as a chimeric antigen receptor with regulatory elements) that is integrated into the genome through homology-directed repair. This segmentation allows the viral vector to remain small and safe while the large construct is delivered separately, resolving the contradiction between delivery capability and safety.
Solution Approach 2:
The patent introduces an intermediary mechanism (homology-directed repair pathway with selectable markers) that mediates the integration of large DNA constructs without requiring large-capacity viral vectors. The selectable marker acts as an intermediary that enables selection of successfully integrated cells, allowing the large construct to be delivered and integrated safely through non-viral methods such as electroporation or nucleofection.
2Reliability
If CAR expression is constitutive, then the antitumor activity is improved, but the off-target toxicity and cell exhaustion worsen
Solution Approach 1:
The system dynamically controls CAR expression through an inducible mechanism. A small activating RNA (saRNA) that can be administered systemically or locally acts as an inducer to activate transcription of the CAR gene only when needed. This dynamic control allows the therapy to be activated on-demand, providing strong antitumor activity when required while minimizing off-target toxicity and cell exhaustion during non-active periods.
Solution Approach 2:
The patent implements periodic activation of CAR expression through repeated administration of inducing agents (such as small molecules or antibodies that trigger saRNA activation). This periodic action pattern allows the CAR to be expressed in pulses rather than continuously, maintaining antitumor efficacy while reducing cumulative toxicity and exhaustion effects on the T cells.
3Manufacturing precision
If large DNA templates are used for gene insertion, then the circuit fidelity and regulatory control are improved, but the insertion difficulty using viral vectors worsens
Solution Approach 1:
The system prepares the genome for precise insertion by first introducing a selectable marker gene through the viral vector that marks the target integration site. This preliminary action creates a selectable phenotype that allows easy identification and selection of cells that have successfully integrated the large DNA construct through homology-directed repair, thereby facilitating the insertion of large templates with high circuit fidelity.
Solution Approach 2:
The patent replaces the mechanical constraint of viral vector capacity limits with a biochemical solution (homology-directed repair mechanism). Instead of forcing large DNA constructs into viral vectors, the system uses cellular repair machinery to integrate large DNA templates that have been introduced through non-viral methods, substituting the mechanical delivery constraint with a biochemical integration pathway that has no size limitation.
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 the safety and therapeutic window of CAR-T cells by ensuring targeted integration, reducing off-target effects, and maintaining circuit fidelity, while allowing for controlled expression of the CAR only upon antigen engagement, thereby minimizing toxicity and exhaustion.
Implementation Method 1
non-viral integration of a DNA template into a genome of a primary cell
Data Source
AI summary
Provided herein are methods of genetically editing cells with large DNA templates using a non-viral editing method. Also provided herein are cells comprising at least one large DNA template non-virally inserted into a target region of the genome of the cell.