Regulatory Nucleic Acid Elements for Stable Expression
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Solution Overview
Problem
The generation of stable cell lines with high expression of therapeutic proteins is hindered by random and undirected integration of recombinant vectors, leading to variable expression levels due to chromosomal positional effects, making the process time-consuming and costly.
Innovation Solution
Incorporation of TE elements, specifically nucleic acids like SEQ ID No. 1, into expression vectors to overcome chromosomal positional effects, resulting in increased productivity and the proportion of high-producing cells by stabilizing gene expression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If recombinant vectors are randomly integrated into the host cell genome, then stable cell lines can be generated, but expression levels vary due to chromosomal positional effects
Solution Approach 1:
The patent introduces chromatin-opening elements (COEs) as intermediary DNA sequences that mediate between the integrated transgene and the chromosomal environment. These COEs act as buffers that prevent negative chromosomal positional effects, ensuring consistent high-level expression regardless of integration site. The COEs create a favorable chromatin environment that protects the transgene from silencing or reduced expression due to nearby chromosomal features.
2Productivity
If strong constitutive promoters and enhancers are used to achieve high product expression, then expression levels increase, but the process remains time-consuming due to screening required to find high-expressing clones
Solution Approach 1:
The patent incorporates chromatin-opening elements (COEs) into the expression vector design before transfection, as a preliminary protective measure. This preliminary action ensures that regardless of where the vector integrates in the genome, the COEs will preemptively create an open chromatin environment that promotes high-level expression. This eliminates the need for extensive screening, as all clones are pre-equipped with the ability to express at high levels.
3Manufacturing precision
If multiple screening steps are performed to identify high-producing clones, then high-expression cell lines can be selected, but the process becomes more costly
Solution Approach 1:
The chromatin-opening elements (COEs) serve as an intermediary mechanism that directly ensures high-level expression without requiring multiple screening steps. By incorporating COEs into the vector, the system preemptively solves the expression variability problem, allowing selection of high-producing clones based on a single transfection event rather than requiring iterative screening and re-selection processes.
Data Source
AI summary
The invention relates to DNA-sequences, especially transcription- or expression-enhancing elements (TE elements) and their use on an expression vector in conjunction with an enhancer, a promoter, a product gene and a selectable marker. TE elements bring about an increase in the expression of the product gene, particularly when stably integrated in the eukaryotic genome, preferably the CHO-DG44 genome.