Human Cone Optogenetic Constructs for Depolarizing Light Response
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Solution Overview
Problem
Existing optogenetic approaches for treating blindness, particularly targeting cone photoreceptors, face challenges such as insufficient light sensitivity of optogenetic proteins, selective expression in cone cells, and lack of translation from animal models to human cells, leading to ineffective vision restoration.
Innovation Solution
Development of novel optogenetic constructs comprising a depolarizing optogenetic protein, specifically a light-gated ion channel polypeptide, combined with a cone-specific promoter and a Woodchuck Hepatitis Virus Posttranscriptional Regulatory element (WPRE), to selectively express and restore light sensitivity in human cone cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hyperpolarizing optogenetic proteins are used to restore cone photoreceptor function, then the natural phototransduction mechanism is recapitulated, but the light sensitivity and functional response are insufficient
Solution Approach 1:
The patent inverts the conventional approach by using depolarizing optogenetic proteins instead of hyperpolarizing proteins. This inversion enables the dormant cone photoreceptors to generate sufficient electrical responses to drive ganglion cell spiking, thereby restoring functional vision output that was not achieved with traditional hyperpolarizing approaches.
Solution Approach 2:
The patent changes the electrical parameter of the optogenetic protein from hyperpolarizing to depolarizing. This parameter change transforms the protein's function, enabling it to generate action potentials in ganglion cells and restore the computational output of the retina, which was the limiting factor in previous approaches.
2Reliability
If optogenetic proteins are expressed in cone cells to restore vision, then light sensitivity is improved, but selective expression in cone cells remains challenging
Solution Approach 1:
The patent applies local quality by using cone-specific promoters (such as ProA7, Pro573.2, and Pro572.2) that drive optogenetic protein expression selectively in cone photoreceptors. This ensures that the depolarizing current is generated only in the appropriate cell type, maintaining the spatial specificity needed for functional vision restoration.
3Reliability
If animal model studies are used to develop optogenetic therapies, then initial functionality is demonstrated, but translation to human cells remains ineffective
Solution Approach 1:
The patent performs preliminary action by validating the optogenetic construct in human cone cells before attempting therapy. The use of humanized rat models and direct human cell experimentation ensures that the depolarizing protein functions correctly in human photoreceptors, establishing translational relevance prior to clinical application.
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
The optogenetic constructs effectively depolarize human cone cells, generating a depolarizing current that induces ganglion cell spiking, thereby restoring light sensitivity and vision in subjects with retinal diseases, particularly those with preserved cone photoreceptor layers.
Implementation Method 1
a light-gated ion channel polypeptide that is selectively expressed in human cone cells... capable of mediating a depolarizing current that depolarizes a human cone cell when exposed to light
Implementation Method 2
generating a depolarizing current that induces spiking of ganglion cells... sufficient to also cause light-modulated current spikes in downstream retinal ganglion cells
Data Source
AI summary
The disclosure relates to nucleic acids comprising a synthetic cone-specific promoter, a depolarizing optogenetic protein and optionally a reporter molecule; and a Woodchuck Hepatitis Virus Posttranscriptional Regulatory element (WPRE). The nucleic acid can be used in vectors or host cells to drive expression of the depolarizing optogenetic protein in retinal cells, particularly cone photoreceptors.