rAAV Vectors with Stopper DNA for Packaging Purity
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Solution Overview
Problem
Adeno-associated viral (AAV) vector manufacturing faces challenges in producing high-quality and quantity vectors due to vector impurities such as non-vector DNA, which can evoke immune responses and other untoward effects in patients.
Innovation Solution
Incorporation of short hairpin nucleic acids, referred to as 'stopper DNA', outside the inverted terminal repeats (ITRs) of rAAV vectors to improve packaging and immunogenicity, thereby reducing reverse packaging of prokaryotic DNA sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional AAV vector manufacturing is used, then vector production can proceed, but vector impurities including non-vector DNA are generated which can evoke immune responses
Solution Approach 1:
The patent applies preliminary action by incorporating stopper sequences into the vector construct before manufacturing. These stopper sequences are designed to prevent reverse packaging of prokaryotic DNA by blocking the replication machinery, thereby preventing the formation of impure vectors before they can be produced. This proactive measure eliminates the harmful impurities at the source rather than attempting to remove them after vector production.
2Productivity
If AAV vectors are produced for therapeutic administration, then high quantity vectors can be manufactured, but vector impurities compromise high quality production
Solution Approach 1:
The patent applies the extraction principle by removing the problematic prokaryotic DNA sequences from the final vector product through the stopper mechanism. The stopper sequences specifically target and prevent the incorporation of plasmid backbone nucleotides and antibiotic resistance genes into the AAV vectors, effectively extracting these harmful elements from the manufacturing process output while maintaining high vector production quantities.
3Ease of manufacture
If reverse packaged prokaryotic DNA is included in vectors, then vector construction is simplified, but clinical safety is compromised due to immune responses
Solution Approach 1:
The patent applies preliminary anti-action by introducing stopper sequences that specifically counteract the reverse packaging process. These stopper sequences are positioned to block the replication and packaging of prokaryotic DNA sequences, creating a preventive barrier against the formation of immunogenic vectors. This approach maintains the simplicity of vector construction while actively preventing the formation of harmful impurities.
Data Source
AI summary
Aspects of the disclosure relate to compositions, such as rAAV vectors, comprising one or more short hairpin nucleic acids positioned outside of the inverted terminal repeats (ITRs) of the rAAV vector (referred to in some embodiments as “stopper DNA”). The disclosure is based, in part, on rAAV vectors comprising stopper DNA, which have improved packaging and/or immunogenicity relative to previously described rAAV vectors. In some embodiments, the disclosure relates to methods of delivering a transgene to a subject comprising administering the rAAV vectors.