Variant AAV Capsid Proteins Enhance Retinal Cell Transduction
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Solution Overview
Problem
Current adeno-associated virus (AAV) vectors face challenges in effectively targeting and transducing deeper cell types of the retina, limiting their efficacy in treating ocular diseases such as inherited retinal diseases and age-related macular degeneration.
Innovation Solution
Development of variant AAV capsid proteins with modified amino acid sequences, specifically peptide insertions and substitutions, to enhance the infectivity of retinal cells, including photoreceptor, ganglion, glial, bipolar, amacrine, horizontal, and retinal pigmented epithelium cells, through directed evolution techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wild-type AAV vectors are used for gene delivery to the retina, then the delivery system is simple and well-characterized, but the transduction efficiency of deeper retinal cell types is insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence of the AAV capsid proteins through directed evolution. Specific mutations are introduced at conserved positions in the capsid structure to alter viral tropism and enhance transduction efficiency of deeper retinal cell types while maintaining overall capsid functionality and simplicity
Solution Approach 2:
The patent uses copying by creating variant capsid proteins that replicate the successful features of wild-type AAV while incorporating specific beneficial mutations. The variant capsids copy the overall structure and delivery mechanism of wild-type AAV but with optimized regions that enhance target cell infectivity
2Reliability
If AAV2 is used as the gene delivery vehicle, then it is the most well-characterized serotype with established safety profile, but it fails to effectively transduce deeper cell types of the retina
Solution Approach 1:
The patent modifies the AAV2 capsid protein parameters through directed evolution, introducing specific amino acid mutations that enhance transduction capability of deeper retinal cell types while preserving the safety profile and well-characterized nature of AAV2
Solution Approach 2:
The patent segments the capsid protein into functional regions, with specific mutations introduced in particular segments to enhance transduction of specific cell types while maintaining the overall functionality and safety characteristics of the AAV2 vector
Data Source
AI summary
Provided herein are variant adeno-associated virus (AAV) capsid proteins having one or more modifications in amino acid sequence relative to a parental AAV capsid protein, which, when present in an AAV virion, confer increased infectivity of one or more types of retinal cells as compared to the infectivity of the retinal cells by an AAV virion comprising the unmodified parental AAV capsid protein. Also provided are recombinant AAV virions and pharmaceutical compositions thereof comprising a variant AAV capsid protein as described herein, methods of making these rAAV capsid proteins and virions, and methods for using these rAAV capsid proteins and virions in research and in clinical practice, for example in, e.g., the delivery of nucleic acid sequences to one or more cells of the retina, for the treatment of retinal disorders and diseases.