Bidirectional hCMV Promoter for Compact Gene Expression Control
Solution Overview
Problem
Existing gene therapy vectors, such as adeno-associated viral vectors, have limited DNA capacity, restricting their utility in delivering recombinant DNA to cells, particularly in gene therapy applications.
Innovation Solution
A bidirectional hCMV immediate-early promoter system is developed, allowing for the simultaneous regulation and promotion of gene expression on both strands of DNA, enabling efficient use of vector space by incorporating a tetracycline-inducible transcription switch and a tet operator/repressor system, which can be integrated into viral vectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional unidirectional promoters are used in viral vectors, then gene expression can be controlled, but the vector DNA capacity is wasted due to inefficient space utilization
Solution Approach 1:
The patent combines two promoter functions into a single bidirectional promoter element that drives transcription of two different genes in opposite directions. This merging of functions allows efficient packing of genetic material into viral vectors while maintaining independent control of each gene through the tetracycline-responsive mechanism
Solution Approach 2:
The bidirectional promoter serves multiple functions: it acts as a transcriptional regulator responsive to tetracycline, provides bidirectional transcription control, and enables compact genetic circuit design. This multi-functionality resolves the contradiction by achieving complex regulatory capabilities within a space-efficient structure suitable for viral vector delivery
2Measurement precision
If the tetracycline repressor system is used to regulate gene expression, then precise control is achieved, but the vector size increases reducing packaging capacity
Solution Approach 1:
The system segments the regulatory function into modular components: the bidirectional promoter contains tet operator sequences that bind the tetracycline repressor, while the repressor gene itself is separately expressed under a constitutive promoter. This segmentation allows precise regulatory control through the tetR-tetO interaction while keeping each component compact for efficient viral vector packaging
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system achieves 100- to 10,000-fold regulation of gene expression in mammalian cells, enhancing the utility of gene therapy vectors by efficiently utilizing available space and allowing for precise control of gene expression.
Implementation Method 1
Gene expression is suppressed in this system by the binding of the tetracycline repressor, tetR, to a tetracycline operator (tetO) sequence
Implementation Method 2
tetracycline is introduced into the system. This enters into cells, binds to the repressor protein and causes it to dissociate from the operator
Implementation Method 3
a bidirectional hCMV promoter that can be used either independently or as part of a system for achieving tetracycline-regulatable gene expression in mammalian cells
Data Source
AI summary
The present invention is directed to a bidirectional human cytomegalovirus (hCMV) promoter that can be used to promote transcription on both strands of a double stranded DNA molecule. When used as part of a system that includes tet operator and the gene coding for the tet repressor, the promoter can be used to induce mammalian gene expression in a highly regulated way.