Abstract
Although cord blood transplantation has significantly extended the lifespan of mucopolysaccharidosis type 1 (MPS1) patients, over 95% manifest cornea clouding with about 50% progressing to blindness. As corneal transplants are met with high rejection rates in MPS1 children, there remains no treatment to prevent blindness or restore vision in MPS1 children. Since MPS1 is caused by mutations in idua, which encodes alpha-L-iduronidase, a gene addition strategy to prevent, and potentially reverse, MPS1-associated corneal blindness was investigated. Initially, a codon optimized idua cDNA expression cassette (opt-IDUA) was validated for IDUA production and function following adeno-associated virus (AAV) vector transduction of MPS1 patient fibroblasts. Then, an AAV serotype evaluation in human cornea explants identified an AAV8 and 9 chimeric capsid (8G9) as most efficient for transduction. AAV8G9-opt-IDUA administered to human corneas via intrastromal injection demonstrated widespread transduction, which included cells that naturally produce IDUA, and resulted in a >10-fold supraphysiological increase in IDUA activity. No significant apoptosis related to AAV vectors or IDUA was observed under any conditions in both human corneas and MPS1 patient fibroblasts. The collective preclinical data demonstrate safe and efficient IDUA delivery to human corneas, which may prevent and potentially reverse MPS1-associated cornea blindness.
Highlights
Mucopolysaccharidosis[1] (MPS1) is an autosomal recessive lysosomal storage disorder caused by null or nonsense mutations in the gene encoding alpha-L-iduronidase (IDUA), a ubiquitous intracellular and secreted enzyme that breaks down glycosaminoglycans (GAGs)
To develop an associated virus (AAV) IDUA expression cassette, the human idua cDNA (NM_000203) was codon optimized for human production and situated between the CMV promoter and the SV40 poly-adenylation sequence in an AAV inverted terminal repeat serotype 2 plasmid context (Fig. 1A)
Our preclinical corneal approach explored was designed as a supplemental mucopolysaccharidosis type 1 (MPS1) therapy to address the shortcomings of stem cell transplantation and AAV gene therapy targeting the Central nervous system (CNS)
Summary
Mucopolysaccharidosis[1] (MPS1) is an autosomal recessive lysosomal storage disorder caused by null or nonsense mutations in the gene encoding alpha-L-iduronidase (IDUA), a ubiquitous intracellular and secreted enzyme that breaks down glycosaminoglycans (GAGs). Central nervous system (CNS) targeted AAV-IDUA gene therapy has been explored in murine, feline, and canine MPS1 models following administration via several routes including the carotid artery, intraparenchymal, intraventricular and intrathecal[2,3,4]. Regarding AAV gene delivery following intrastromal injection into human cornea explants, it was observed that AAV8 was more efficient than AAV2 or AAV1 for stromal transduction, which encompassed multiple cell types including CD34 + keratocytes and macrophages[14] Both of these routes of drug administration observed no deleterious consequences related to the AAV vector[13,14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
