498. Optimization of rAAV Targets ON Bipolar Cells and Rescues the nobnyx Mouse Model of X-Linked Congenital Stationary Night Blindness
Bibliographic record
Abstract
Within the retina, Adeno associated virus (AAV) has been effectively used to target photoreceptors, retinal pigment epithelial cells, muller glia and retinal ganglion cells. However, transduction of cells in the middle of non-degenerate retina has proven more difficult. Transduction of bipolar cells is particularly attractive both for treating forms of Congenital Stationary Night Blindness (CSNB), in which the ON-type bipolar cells are unable to receive electrochemical input from photoreceptors, as well as for use in optogenetics. Even more attractive is the ability to target this cell type via a non-invasive intravitreal injection. The purpose of our study was to establish methodology to robustly and exclusively express transgene in ON bipolar cells utilizing AAV vectors, and to use these tools to restore retinal function to an animal model of the X-linked form of complete CSNB. Like patients, the nobnyx mouse carries a mutation in NYX, which encodes nyctalopin, a protein essential for proper localization of the TRPM1 cation channel in ON BCs. This disease is characterized by an absence of the electroretinogram (ERG) b-wave in addition to a high incidence of myopia, nystagmus, strabismus, and low visual acuity. A construct containing an ON BC specific promoter, Ple155, driving either hGFP or YFP_Nyx was packaged into rationally designed AAV2(quadY-F+T-V). nobnyx mice were intravitreally injected with 6.5×1012 VG/ml. GFP expression and localization were confirmed using immunohistochemistry before proceeding with Nyx replacement. ERG was performed 4 weeks post injection on mice injected with the YFP_Nyx vector, and then retinas were harvested for single cell recordings, and immunohistochemistry. Mice intravitreally injected with Ple155-hGFP had robust and exclusive GFP expression in their ON bipolar cells. Additionally, Ple155-YFP_Nyx- injected mice exhibited NYX (YFP) expression exclusively in ON BCs, as well as restoration of the glutamate cascade, as evidenced by wild-type responses to capsaicin, an agonist of the disrupted TRPM1 cation channel, in a YFP+ cell. Both scotopic and photopic ERG b-waves were restored to P2-treated mice. This is the first demonstration of therapy following gene replacement in a model of ONBC-mediated disease and provides proof of concept for an AAV-based strategy to treat Congenital Stationary Night Blindness and effectively target ON BCs. Efforts are currently underway to further modify the AAV capsid and genome in order to enhance transduction and increase window of therapy.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".