Evolved Bxb1 and PhiC31 Integrases for Large-Cargo Genome Insertion
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Solution Overview
Problem
Current genetic editing technologies, such as CRISPR-based methods, struggle with inefficient insertion of large DNA cargos, particularly in non-dividing cells, leading to uncontrolled deletions and chromosomal rearrangements, and existing integrase-mediated integration methods are not sufficiently efficient for therapeutic applications.
Innovation Solution
Development of evolved Bxb1 and PhiC31 integrases with specific mutations that enhance their ability to insert large DNA cargos into specific genomic sites, reducing off-target effects and increasing insertion efficiency up to 80% in optimized conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If CRISPR nuclease-induced HDR is used for large cargo insertion, then insertion capability is improved, but insertion efficiency drops significantly
Solution Approach 1:
The patent introduces integrase-mediated site-specific recombination as an intermediary mechanism to replace the inefficient HDR pathway for large cargo insertion. The integrase enzyme acts as a mediator that facilitates precise integration of large DNA cargos into genomic attP sites without requiring homologous recombination, thereby maintaining high insertion efficiency while enabling large cargo delivery
Solution Approach 2:
The patent evolves integrase variants with modified amino acid sequences to optimize their catalytic activity and specificity. By changing parameters such as integrase concentration, mutation combinations (e.g., Bxb1 integrase variants), and recognition site configurations, the system achieves enhanced insertion efficiency for large cargos compared to wild-type integrase
2Quantity of substance
If NHEJ-based insertion methods are used, then insertion capability is improved, but uncontrolled deletions and chromosomal rearrangements occur
Solution Approach 1:
The patent employs integrase as a site-specific intermediary that mediates recombination between defined attB and attP sequences. This controlled mechanism replaces the error-prone NHEJ pathway, enabling insertion capability while maintaining genomic stability through precise, predictable recombination events at specific genomic loci
Solution Approach 2:
The patent requires pre-installation of integrase recognition sites (attP) at desired genomic locations before cargo delivery. This preliminary action ensures that subsequent integrase-mediated insertion occurs only at predetermined safe harbor locations, preventing uncontrolled deletions and chromosomal rearrangements associated with NHEJ
3Manufacturing precision
If HDR is used for gene insertion, then insertion precision is improved, but functionality is lost in non-dividing cells
Solution Approach 1:
The patent replaces the HDR mechanical system (which requires homologous recombination machinery active in dividing cells) with an integrase-mediated recombination system. This substitution enables precise gene insertion in non-dividing cells by utilizing a different molecular mechanism that does not depend on cell division or HDR pathway activation
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 evolved integrases significantly improve the efficiency of genetic editing by achieving up to 80% insertion into haploid genomes, minimizing off-target effects, and enabling more effective therapeutic interventions for genetic diseases.
Implementation Method 1
the evolved integrase binds to the integrase recognition sequence and alters the sequence of the genome of the cell
Data Source
AI summary
Disclosed are evolved Bxb1 and PhiC31 integrases that exhibit increased insertion activity and efficiency as compared to their wild-type counterparts and use of the evolved integrases to modify any sequence within the genome of a cell or subject.