Chimeric Gene Regulatory Units for High-Level Expression
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Solution Overview
Problem
Current methods for recombinant protein production in mammalian cells, such as CHO cells, face limitations in achieving high expression levels due to challenges in transcriptional efficiency and promoter silencing, necessitating the development of more effective gene regulatory units for enhanced protein production.
Innovation Solution
The development of novel chimeric gene regulatory units comprising functional enhancer, promoter, and intron sequences from different species, specifically designed to enhance transcriptional activity and resistance to silencing, are used to drive high-level expression of recombinant proteins in CHO cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional promoters are used for recombinant protein production, then the expression system is simple and well-established, but the recombinant protein yield is limited due to transcriptional efficiency and promoter silencing
Solution Approach 1:
The patent applies composite materials principle by creating chimeric gene regulatory units that combine promoter sequences from different species (e.g., CMV promoter from human, SV40 enhancer from simian virus). This composite approach allows the regulatory unit to harness the strengths of different parental promoters, achieving both high transcriptional activity and resistance to silencing, thereby resolving the contradiction between productivity improvement and complexity increase
Solution Approach 2:
The patent segments the gene regulatory unit into distinct functional modules: enhancer regions, core promoter regions, and intron sequences. Each module is independently optimized and can be combined in various configurations. This segmentation allows systematic optimization of transcriptional efficiency and silencing resistance without requiring complete redesign of the entire regulatory system
2Productivity
If gene amplification and sub-cloning are used to increase specific productivity, then recombinant protein expression improves, but the development time and process complexity increase
Solution Approach 1:
The patent implements preliminary action by pre-optimizing the gene regulatory units with chimeric promoter designs that inherently provide high and stable expression. This preliminary optimization is performed at the molecular design stage, allowing direct transfection and expression without requiring subsequent rounds of cell line development, gene amplification, or extensive sub-cloning, thereby dramatically reducing development time while maintaining high productivity
3Ease of operation
If transient expression is used instead of stable integration, then the process is faster and simpler, but the expression level and sustainability are limited
Solution Approach 1:
The patent applies parameter changes by modifying the transcriptional parameters of the gene regulatory units through chimeric promoter design. The optimized regulatory units achieve expression levels and stability previously associated only with stable integration, but can now be delivered via transient transfection methods. This changes the expression parameters to allow high productivity through simpler transient processes
Data Source
AI summary
The present invention provides for functional chimeric gene regulatory units capable of driving strong and sustained heterologous gene expression.