5′ Cap RNA Constructs for Higher Capping and Translation Efficiency
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Solution Overview
Problem
Existing challenges in the production of RNA therapeutics include low capping efficiency, poor translation efficiency, and high levels of short polynucleotide byproducts, which affect the quality and efficacy of RNA preparations.
Innovation Solution
The use of specific 5' cap structures, such as trinucleotide caps comprising N1pN2, where N1 is A or an analog and N2 is U or an analog, paired with certain transcription start sites, enhances RNA transcription, capping efficiency, and translation efficiency, while reducing the formation of short contaminants and toxicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dinucleotide cap analogs (e.g., β-S-ARCA) are used to improve resistance to decapping enzymes and IFITs, then RNA stability and immune evasion are improved, but capping efficiency deteriorates due to competition with GTP in transcription reaction
Solution Approach 1:
The patent changes the chemical structure parameter of the cap analog from dinucleotide to trinucleotide configuration. Specifically, it uses cap1 analogs with the structure (m7)GpppN1N2 where N1 and N2 are specific nucleotides (e.g., A and U), which fundamentally alters how the cap interacts with GTP during transcription, thereby improving capping efficiency while maintaining resistance properties
Solution Approach 2:
The patent creates a composite cap structure by combining multiple nucleotide units (GpppN1N2) into a single cap analog molecule. This composite trinucleotide structure integrates both the protective functions (resistance to decapping enzymes and IFITs) and the transcription-compatible properties, resolving the contradiction between stability and capping efficiency
2Quantity of substance
If conventional cap analogs are used to achieve basic capping function, then RNA is produced, but translation efficiency and polypeptide payload expression deteriorate
Solution Approach 1:
The patent optimizes specific parameters of the cap structure by using cap1 analogs with defined nucleotide sequences (e.g., GpppAU). This precise parameter optimization enhances the interaction between the cap and translation initiation factors, thereby improving translation efficiency and polypeptide expression without sacrificing RNA production levels
3Quantity of substance
If standard in vitro transcription is used to produce RNA, then RNA is generated, but short polynucleotide byproducts increase reducing preparation quality
Solution Approach 1:
The patent applies preliminary action by pre-optimizing the transcription system components, specifically using cap1 analogs that are compatible with T7 RNA polymerase and designed to minimize premature termination. This preliminary optimization of transcription conditions and reagents prevents the formation of short byproducts before they occur, thereby improving RNA preparation quality
Data Source
AI summary
Disclosed herein are RNA polynucleotides comprising a 5′ Cap, a 5′ UTR comprising a cap proximal sequence disclosed herein, and a sequence encoding a payload. Also disclosed herein are compositions and medical preparations comprising the same, and compositions and methods of making and using the same.