Artificial Expression Constructs for Neocortical L4 and L5 IT Neuron Targeting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for labeling and perturbing specific cell types in the central nervous system, such as neocortical layer 4 (L4) intratelencephalic (IT) neurons, are costly and require triple transgenic crosses, yielding low frequencies of experimental animals. Additionally, these tools are not applicable to humans due to their reliance on germline transgenic animals.
Innovation Solution
The development of artificial expression constructs that utilize specific enhancers, such as eHGT_598h, eHGT_671m, and 3xCore-eHGT_058h, to drive gene expression in targeted central nervous system cell populations, including neocortical L4 IT neurons and L5 IT neurons, providing higher levels and more rapid onset of transgene expression compared to single full-length enhancers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If recombinase driver lines are used to label cell populations, then cell type specificity is improved, but device complexity and cost increase due to requiring triple transgenic crosses
Solution Approach 1:
The patent extracts the cell type specificity function from complex recombinase driver lines and transfers it to viral vectors containing cell type-specific enhancers. This allows the specificity to be delivered independently without requiring triple transgenic crosses, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The patent introduces viral vectors as an intermediary carrier that delivers cell type-specific enhancer sequences to target cells. This intermediary approach replaces the need for complex germline transgenic crosses by using a deliverable vector system that achieves the same specificity through enhancer-driven expression.
2Measurement precision
If recombinase driver lines are used to label cell populations, then cell type specificity is improved, but productivity decreases due to low frequency of experimental animals
Solution Approach 1:
The patent extracts the cell type specificity from germline transgenic lines and encapsulates it in viral vectors. This extraction allows the specificity to be delivered to any target cell type without being constrained by the low yield of triple transgenic crosses, thereby improving productivity while maintaining specificity.
Solution Approach 2:
The patent uses viral vectors to copy and deliver cell type-specific enhancer sequences to target cells. This copying mechanism bypasses the need for generating rare triple transgenic animals, as the specificity is replicated and delivered through the viral vector system, significantly improving experimental animal yield.
3Measurement precision
If germline transgenic animals are used, then cell type specificity is achieved, but adaptability decreases due to inapplicability to humans
Solution Approach 1:
The patent creates a universal system using viral vectors and cell type-specific enhancers that can be applied across different species including humans. The enhancer sequences are designed to be species-applicable, allowing the same methodology to achieve cell type specificity in both animal models and human subjects, thereby improving adaptability.
Solution Approach 2:
The patent uses viral vectors as an intermediary delivery system that bridges the gap between germline transgenic approaches and human applications. This intermediary approach allows cell type-specific expression to be achieved in humans through viral delivery of enhancer sequences, bypassing the limitation of germline transgenics being restricted to animal models.
4Quantity of substance
If single full-length enhancers are used, then gene expression is achieved, but transgene expression levels and onset speed are insufficient
Solution Approach 1:
The patent combines multiple enhancer sequences into composite enhancer structures within viral vectors. This merging of enhancer elements creates synergistic effects that dramatically increase transgene expression levels and accelerate expression onset compared to single full-length enhancers, resolving the contradiction between expression quantity and time.
Data Source
AI summary
Artificial expression constructs for modulating gene expression in targeted central nervous system cell types are described. The artificial expression constructs can be used to express synthetic genes or modify gene expression in neocortical layer 4 (L4) intratelencephalic (IT) neurons and/or neocortical L5 IT neurons.