Biology subjects

Boye, S. E.

Publications and source records attributed to Boye, S. E..

4 recordsLinked to original sources

bioRxiv2026

Preclinical Development and Safety of Laterally Spreading Dual AAV.SPR-MYO7A Vectors for the Treatment of Usher Syndrome Type 1B

Usher syndrome type 1B (USH1B), caused by mutations in MYO7A, is the most severe form of Usher syndrome and accounts for more than 50% of USH1 cases. Affected patients are born profoundly deaf with vestibular dysfunction and develop progressive retinitis pigmentosa, for which no approved treatment exists. The MYO7A coding sequence exceeds the packaging capacity of adeno-associated virus (AAV), the gold standard vector for retinal gene therapy. To overcome this, we developed dual AAV hybrid and overlap platforms to reconstitute full-length MYO7A expression in photoreceptors and retinal pigment epithelium. Modification of cDNA split points, and reduction of non-coding sequence yielded optimized vector pairs that produced higher full-length MYO7A levels with substantially reduced truncated protein. Packaging in the laterally spreading AAV.SPR capsid enabled supraphysiological MYO7A expression in cynomolgus macaques at macular and distal retinal sites without requiring foveal detachment, an important safety consideration for USH1B patients with remaining central vision. A six-month GLP toxicology study confirmed that ATSN-301, an AAV.SPR-based dual vector reconstituting MYO7A driven by the smCBA promoter, was well tolerated at all doses, with a No Observed Adverse Effect Level established at 1.2E11 vg/eye, supporting its clinical advancement for USH1B.

genetics↗

bioRxiv2024

Dual-acting gene therapy targeting HIF1A and HIF2A by RNA interference mitigates retinal degeneration in two mouse models of AMD

Age-related tissue changes lead to reduced oxygen delivery to photoreceptors and the retinal pigment epithelium (RPE), and contribute to the pathology of age-related macular degeneration (AMD). The implication of hypoxia-inducible factors (HIFs) in this process makes them good candidates as therapeutic targets for AMD. We developed a multiplex dual-acting therapy utilizing the shRNAmir system, delivered by a single AAV, that reduces mRNA levels of Hif1a in photoreceptors and Hif2a in the RPE. This RNA interference-based strategy demonstrated a strong therapeutic effect, potently preserving photoreceptors and the RPE in two models of pseudo- and true hypoxia up to 61 weeks post-injection. The efficacy of our dual-acting virus proved superior to single-acting viruses targeting only Hif1a in photoreceptors or Hif2a in the RPE. By targeting a common, conserved disease pathway, this gene-agnostic RNAi therapy shows significant potential to protect tissues from chronic hypoxic insults in complex diseases such as AMD.

neuroscience↗

bioRxiv2023

Improving retinal vascular endothelial cell tropism through rational rAAV capsid design

Vascular endothelial cells (VEC) are essential for retinal homeostasis and their dysfunction underlies pathogenesis in diabetic retinopathy (DR) and exudative age-related macular degeneration (AMD). Studies have shown that recombinant adeno-associated virus (rAAV) vectors are effective at delivering new genetic material to neural and glial cells within the retina, but targeting VECs remains challenging. To overcome this limitation, herein we developed rAAV capsid mutant vectors with improved tropism towards retinal VEC. rAAV2/2, 2/2[QuadYF-TV], and rAAV2/9 serotype vectors (n=9, capsid mutants per serotype) expressing GFP were generated by inserting heptameric peptides (7AA) designed to increase endothelial targeting at positions 588 (2/2 and 2/2[QuadYF-TV] or 589 (2/9) of the virus protein (VP 1-3). The packaging and transduction efficiency of the vectors were assessed in HEK293T and bovine VECs using Fluorescence microscopy and flow cytometry, leading to the identification of one mutant, termed EC5, that showed improved endothelial tropism when inserted into all three capsid serotypes. Intra-ocular and intravenous administration of EC5 mutants in C57Bl/6j mice demonstrated moderately improved transduction of the retinal vasculature, particularly surrounding the optic nerve head, and evidence of sinusoidal endothelial cell transduction in the liver. Most notably, intravenous administration of the rAAV2/2[QuadYF-TV] EC5 mutant led to a dramatic and unexpected increase in cardiac muscle transduction.

molecular biology↗

bioRxiv2020

SARM1 depletion rescues NMNAT1 dependent photoreceptor cell death and retinal degeneration.

Leber congenital amaurosis type 9 is an autosomal recessive retinopathy caused by mutations of the NAD+ synthesis enzyme NMNAT1. Despite the ubiquitous expression of NMNAT1, patients do not manifest pathologies other than retinal degeneration. Here we demonstrate that widespread NMNAT1 depletion in adult mice mirrors the human pathology, with selective loss of photoreceptors highlighting the exquisite vulnerability of these cells to NMNAT1 loss. Conditional deletion demonstrates that NMNAT1 is required within the photoreceptor. Mechanistically, loss of NMNAT1 activates the NADase SARM1, the central executioner of axon degeneration, to trigger photoreceptor death and vision loss. Hence, the essential function of NMNAT1 in photoreceptors is to inhibit SARM1, highlighting an unexpected shared mechanism between axonal degeneration and photoreceptor neurodegeneration. These results define a novel SARM1-dependent photoreceptor cell death pathway and identifies SARM1 as a therapeutic candidate for retinopathies.

neuroscience↗