CLDN5 Mini-Promoters for Brain-Specific Gene Expression
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Solution Overview
Problem
There is a significant need for minimal human promoter elements capable of driving specific expression in brain cell types and regions, as existing promoters lack the necessary specificity and efficiency for targeted gene expression in the brain.
Innovation Solution
The development of novel CLDN5 mini-promoters, comprising CLDN5 regulatory elements operably linked in a non-native conformation to a CLDN5 basal promoter, which are capable of directing expression in specific cell types and regions of the brain, such as blood vessel cells and retinal cells, by utilizing sequences substantially similar to SEQ ID NOs: 1, 2, and 4, and linked to expressible sequences like reporter genes or therapeutic proteins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If native CLDN5 promoter sequences are used, then expression specificity in brain cell types is achieved, but promoter size is large and genetic manipulation is difficult
Solution Approach 1:
The patent extracts only the essential regulatory elements (enhancers and core promoter regions) from the native CLDN5 promoter, creating a mini-promoter that maintains cell-type specific expression while reducing overall size. This extraction of critical functional elements resolves the contradiction between maintaining reliability and reducing complexity.
Solution Approach 2:
The patent segments the native promoter into distinct functional modules (enhancer elements and core promoter) that can be recombined in non-native configurations. This segmentation allows creation of mini-promoters with optimized sizes while preserving the essential expression specificity function.
2Reliability
If native CLDN5 promoter sequences are used, then functional expression activity is maintained, but the promoter is too large for efficient use in expression constructs
Solution Approach 1:
The patent extracts only the minimal necessary elements (enhancer regions and core promoter) required for functional expression activity, discarding non-essential sequences. This creates a compact mini-promoter that maintains functional activity while significantly improving ease of manufacture and use in expression constructs.
Solution Approach 2:
The patent changes the size parameter of the promoter by creating truncated versions that retain functional activity. By optimizing the length and composition of regulatory elements, the mini-promoters achieve efficient use in expression constructs while maintaining reliable functional expression.
3Reliability
If CLDN5 regulatory elements are arranged in native conformation, then natural expression patterns are preserved, but flexibility for genetic engineering is limited
Solution Approach 1:
The patent segments the promoter into modular regulatory elements that can be independently manipulated and recombined. This segmentation allows researchers to maintain native conformations when fidelity is needed, while also enabling flexible reconfiguration for different genetic engineering applications.
Solution Approach 2:
The patent creates mini-promoters with universal regulatory elements that can function in multiple contexts and configurations. The modular design allows the same regulatory elements to be used in native or non-native arrangements, providing both expression pattern fidelity and genetic engineering flexibility.
4Reliability
If full native promoter sequences are used, then complete regulatory control is achieved, but time and resources for cloning and manipulation are excessive
Solution Approach 1:
The patent extracts only the critical regulatory elements necessary for complete regulatory control, eliminating redundant or non-essential sequences. This extraction dramatically reduces cloning and manipulation time while preserving the completeness of regulatory control needed for proper gene expression.
Solution Approach 2:
The patent uses partial promoter sequences (mini-promoters) that contain just enough regulatory elements to achieve complete regulatory control. By using partial rather than full sequences, the patent reduces time and resources for cloning while maintaining sufficient regulatory functionality.
Data Source
AI summary
Isolated polynucleotides comprising a CLDN5 mini-promoter are provided. The mini-promoter may be operably linked to an expressible sequence, e.g. reporter genes, genes encoding a polypeptide of interest, regulatory RNA sequences such as miRNA, siRNA, anti-sense RNA, etc., and the like. In some embodiments a cell comprising a stable integrant of an expression vector is provided, which may be integrated in the genome of the cell. The mini-promoter may also be provided in a vector, for example in combination with an expressible sequence. The polynucleotides find use in a method of expressing a sequence of interest, e.g. for identifying or labeling cells, monitoring or tracking the expression of cells, etc.