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Principal Investigator: Renee Christine Ryals
Organization: OREGON HEALTH & SCIENCE UNIVERSITY
Fiscal Year: 2024
Award: $100,786
Funding agency: National Eye Institute
PROJECT SUMMARY
Inherited retinal dystrophies (IRDs) are a group of genetically and clinically heterogenous diseases, inherited in
an autosomal dominant, recessive, or X-linked pattern. With an estimated incidence of 1:2000-1:3000, IRDs
are the leading cause of vision loss in persons aged 15 to 45. To date, mutations in 280 distinct genes have
been associated with retinal pathology. Gene augmentation, editing, and silencing are the most attractive
therapeutic strategies for these patients as they correct the causative genomic malfunction. Currently, there is
only one FDA approved gene augmentation therapy for one IRD in this large family of retinal degenerations.
Our long-term goal is to generate novel gene editing platforms for IRDs. The most clinically advanced gene
editing therapeutic for retinal degeneration is EDIT-101, which uses a viral vector (AAV) to deliver the Cas9
endonuclease and two guide RNAs that target the CEP290 gene in Leber Congenital Amaurosis type 10
patients. While this is the first in-vivo CRISPR/Cas9 clinical trial underway to treat retinal degeneration, the trial
is currently paused, suggesting there is room for improvement in the efficacy of this product either through
modulating the gene editing tools, or the delivery platform. Delivering the Cas9 endonuclease in the form of
mRNA, which leads to transient, robust protein expression, would mitigate safety concerns associated with
AAV-mediated Cas9. These safety concerns include persistent expression of Cas9 endonuclease and AAV
integration into the Cas9-induced double strand breaks. Lipid-based nanoparticles (LNPs) are the most
clinically advanced non-viral platform that can encapsulate mRNA and deliver genome editors. Systemic
administration of LNPs, that encapsulate Cas9 mRNA and a guide RNA targeting transthyretin (TTR), has led
to a 90% reduction in misfolded TTR protein in amyloidosis patients. To translate these therapeutic gains
observed in the liver to the retina, we first measured gene editing events following subretinal administration of
an LNP encapsulating Cas9 mRNA and guide RNA in Ai9 mice. In this proposal, we show significant LNP-
mediated gene editing in the murine retina. Additionally, we were one of the first groups to deliver LNPs to the
subretinal space of rhesus macaques and demonstrate their ability to transfect photoreceptors. To advance the
development of LNP-mediated gene editing therapies for IRDs, there are three critical gaps of knowledge
we propose to address in the most clinically relevant model, the nonhuman primate (NHP): 1) determine which
physiochemical features of LNPs facilitate photoreceptor expression of gene editors, 2) evaluate the
immunogenicity of LNPs in the subretinal space, and 3) quantify in-vivo gene editing efficiency in the
photoreceptors. Successful completion of these aims will generate novel LNP platforms that mediate the
expression of gene editors in NHP photoreceptors. This will lead to an understanding of in-vivo gene editing in
large animals that can be translated to specific IRD mutations. Overall, these studies will advance the
development of LNP gene editing therapeutics for IRDs.
Terms: <Address><Advanced Development><Affect><Amyloidosis><Animal Model><Animal Models and Related Studies><Animals><Area><Bar Codes><Blindness><Blood><Blood Reticuloendothelial System><Body Tissues><CRISPR approach><CRISPR based approach><CRISPR method><CRISPR methodology><CRISPR technique><CRISPR technology><CRISPR tools><CRISPR-CAS-9><CRISPR-based method><CRISPR-based technique><CRISPR-based technology><CRISPR-based tool><CRISPR/CAS approach><CRISPR/Cas method><CRISPR/Cas technology><CRISPR/Cas9><CRISPR/Cas9 technology><Cas nuclease technology><Cell Body><Cells><Clinical><Clinical Trials><Clustered Regularly Interspaced Short Palindromic Repeats approach><Clustered Regularly Interspaced Short Palindromic Repeats method><Clustered Regularly Interspaced Short Palindromic Repeats methodology><Clustered Regularly Interspaced Short Palindromic Repeats technique><Clustered Regularly Interspaced Short Palindromic Repeats technology><DNA editor><Data><Disease><Disorder><Dose><Electroretinography><Encapsulated><Event><FDA approved><Family><Gene Expression><Genes><Genetic Alteration><Genetic Change><Genetic defect><Genomics><Goals><Guide RNA><Harvest><Hereditary><Hortega cell><Hour><Immune response><Immunoblotting><Immunofluorescence><Immunofluorescence Immunologic><Immunological response><In Vitro><Incidence><Individual><Inherited><Injections><Innate Immune Response><Investigation><Knowledge><Leber congenital amaurosis><Leber's amaurosis><Leber's congenital amaurosis><Libraries><Link><Liver><M mulatta><M. mulatta><Macaca mulatta><Macrophage Activation><Measures><Mediating><Messenger RNA><Mice><Mice Mammals><Microglia><Modeling><Modification><Murine><Mus><Mutation><Pathology><Patients><Pattern><Persons><Photoreceptor Cell><Photoreceptors><Photosensitive Cell><Prealbumin><Proalbumin><Proteins><Retina><Retinal Degeneration><Retinal Dystrophy><Rhesus Macaque><Rhesus Monkey><Rhodopsin><Safety><Saline><Saline Solution><Sampling><Surface><T cell infiltration><Testing><Therapeutic><Therapeutic Gene Editing><Tissues><Transfection><Translating><Transthyretin><Viral Vector><Visual Purple><Visual Receptor><Western Blotting><Western Immunoblotting><adaptive immune response><aged><amaurosis congenita of Leber><amyloid disease><autosome><barcode><cell type><clinical relevance><clinically relevant><congenital amaurosis of retinal origin><cytokine><deep sequencing><degenerative retina diseases><design><designing><electroretinogram><endonuclease><gRNA><gene augmentation intervention><gene augmentation therapy><gene editing platform><gene editing system><gene editing technology><gene editing tools><gene editor><gene-editing therapy><gene-editing toolkit><genome editing based therapy><genome editing therapy><genome editing treatment><genome editing-based therapeutics><genome editor><genome mutation><gitter cell><hepatic body system><hepatic organ system><host response><immune system response><immunogenicity><immunoresponse><improved><in vivo><indel><inherited retinal degeneration><insertion-deletion><insertion-deletion mutation><insertion/deletion><insertion/deletion mutation><knock-down><knockdown><lipid based nanoparticle><lipid nanoparticle><mRNA><mesoglia><microglial cell><microgliocyte><model of animal><nano particle delivery><nanoparticle delivered><nanoparticle delivery><non-human primate><nonhuman primate><novel><perivascular glial cell><protein blotting><protein expression><retina degeneration><retinal degenerative><retinal degenerative diseases><scRNA-seq><single cell RNA-seq><single cell RNAseq><single cell expression profiling><single cell transcriptomic profiling><single-cell RNA sequencing><subretinal injection><therapeutic editing><therapeutic genome editing><timeline><vision loss><visual loss>