AAV Vector Gene Expression via ITR and Regulatory Elements
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Solution Overview
Problem
Current methods for producing genetically encoded therapeutic proteins, such as antibodies, face limitations in gene expression levels and are hindered by endogenous immune responses and the inability of adeno-associated virus (AAV) vectors to transmit sequences greater than approximately 4800 base pairs in length, making it difficult to design vectors for high-level production, particularly in vivo.
Innovation Solution
Development of a viral vector comprising a 5' inverted terminal repeat (ITR) of AAV, a promoter with at least 90% sequence identity to a specified nucleic acid, a restriction site for inserting a polynucleotide encoding a protein of interest, and a posttranscriptional regulatory element, located downstream of the 5' ITR and upstream of the 3' ITR, to enhance gene expression and overcome the limitations of existing AAV vectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional AAV vectors are used for gene delivery, then the vector structure is simple and易于制造, but the gene expression level is limited and cannot transmit sequences greater than approximately 4800 base pairs
Solution Approach 1:
The vector system is divided into multiple components: AAV capsid proteins for delivery, ITR sequences for replication, and modular expression cassettes. This segmentation allows each component to be optimized independently while maintaining overall functionality within the 4.7kb packaging limit.
Solution Approach 2:
The patent employs nested structural elements including ITR sequences that contain terminal resolution sites, promoters nested within the expression cassette, and multiple regulatory elements layered within the limited vector space to maximize gene expression capability.
2Productivity
If the AAV vector packaging capacity is increased to accommodate larger sequences for high-level expression, then gene expression potential is improved, but the vector cannot be properly packaged and transmitted
Solution Approach 1:
The patent extracts essential regulatory elements (promoters, ITRs, polyadenylation signals) and places them in optimized configurations within the 4.7kb packaging limit, removing non-essential sequences while retaining core functionality for high-level expression.
Solution Approach 2:
The patent optimizes parameters including promoter strength, ITR configuration, and coding sequence efficiency to maximize protein production within the strict 4.7kb size constraint, using compact but highly effective regulatory elements.
3Productivity
If alternative capsids and self-complementary AAV vectors are used to increase expression, then antibody production is improved, but the carrying capacity is reduced and endogenous immune response occurs
Solution Approach 1:
The patent uses the endogenous immune response against the immunoadhesin as a selective pressure to identify and characterize naturally occurring neutralizing antibodies, converting a harmful immune response into a beneficial source of therapeutic antibodies.
Solution Approach 2:
The patent employs AAV vectors as intermediaries to deliver genes encoding neutralizing antibodies, using the viral delivery system to bypass the immune response issue while achieving therapeutic protein production.
Data Source
Figure 1A~1B
Figure 1C~1E
Figure 2
AI summary
Disclosed herein are compositions, systems and methods for delivery of proteins of interest using adeno-associated virus (AAV) vectors. AAV vectors comprising 5' and 3' inverted terminal repeats (ITR), a promoter, a restriction site for insertion of a polynucleotide and a posttranscriptional regulatory element are disclosed. The use of AAV vectors for the expression of neutralizing antibodies is further disclosed.