Unidirectional Antibody Expression Vector Design
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Solution Overview
Problem
Current methods for recombinant antibody production in eukaryotic cells face challenges in optimizing expression cassette organization and promoter selection for stable and high-yield production, with varying results depending on vector design and promoter choice.
Innovation Solution
The use of expression vectors with a unidirectional arrangement of antibody heavy chain, light chain, and selection marker cassettes, specifically with the human cytomegalovirus promoter (hCMV) and bovine growth hormone polyA signal, and optionally the human gastrin gene terminator, to enhance productivity and stability of antibody production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different promoter sequences are used in expression vectors, then expression levels of antibody chains can be independently optimized, but it becomes difficult to achieve stoichiometrically equivalent expression of heavy and light chains
Solution Approach 1:
The invention divides the expression system into separate expression cassettes for heavy chain and light chain, each with its own promoter. This allows independent optimization of expression levels for each chain while maintaining the ability to achieve stoichiometric equivalence through careful design of the expression cassettes and selection markers.
Solution Approach 2:
The invention changes the promoter parameter by providing specific promoter sequences (such as CMV, EF1α, or other mammalian promoters) that can be selected and optimized to achieve desired expression levels. The patent describes how different promoter strengths can be balanced with corresponding selection marker expression to maintain stoichiometric equivalence between heavy and light chains.
2Adaptability or versatility
If expression cassettes are arranged in different configurations, then flexibility in vector design is improved, but it becomes difficult to optimize both transcription efficiency and selection marker function
Solution Approach 1:
The invention segments the expression vector into distinct expression cassettes, each containing a promoter, coding sequence, and polyadenylation signal. This segmentation allows flexible arrangement of heavy chain and light chain expression cassettes in different configurations (e.g., same orientation or opposite orientations) while maintaining optimal transcription efficiency for each cassette.
Solution Approach 2:
The invention adds dimensional flexibility by allowing expression cassettes to be arranged in different spatial configurations within the vector - including same orientation, opposite orientations, or different physical locations. This dimensional arrangement optimization enables simultaneous achievement of transcription efficiency and selection marker function without compromising either.
3Stability of the object's composition
If polyadenylation signals from different sources are used, then expression stability can be optimized, but it increases the complexity of vector construction
Solution Approach 1:
The invention provides a universal approach by specifying that polyadenylation signals can be derived from various sources (bovine growth hormone, SV40, adenovirus, or other eukaryotic sequences) and can be used in a standardized manner across different expression cassettes. This universal polyA signal design simplifies vector construction by providing a common element that can be repeatedly used to achieve expression stability without increasing complexity.
Data Source
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AI summary
Herein is reported an expression vector comprising - an antibody light chain expression cassette, - an antibody heavy chain expression cassette, and - a selection marker expression cassette, wherein the expression cassettes are arranged unidirectional, and wherein the expression cassettes are arranged in the 5' to 3' sequence of antibody heavy chain expression cassette, antibody light chain expression cassette and selection marker expression cassette. Further are reported herein methods for the generation of antibody producing cells and the use of these cells for the recombinant production of antibodies.