Vika-Based HdAd Production System for Genetic Intersectional Strategies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current viral vector systems, such as rAAV and LVV, have limited packaging capacity, restricting the delivery of large proteins or transgene cassettes, and reliance on Cre or Flp recombination limits the production of helper-dependent adenovirus (HdAd) vectors, preventing the use of genetic intersectional strategies for cell-type specific expression.
Innovation Solution
A Vika-based production system that utilizes a producer cell line expressing Vika recombinase and a helper virus with vox sites, allowing for efficient replication and production of HdAd vectors independent of Cre or Flp recombination, enabling the inclusion of site-specific recombinase recognition sites like loxP, FRT, and others.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Cre or Flp recombination is used for HdAd production, then production efficiency is improved, but the ability to use genetic intersectional strategies is lost
Solution Approach 1:
The patent introduces Vika recombinase as an intermediary enzyme that mediates recombination between vox sites, replacing the conventional Cre or Flp recombinase system. This intermediary enables HdAd production while preserving compatibility with genetic intersectional strategies, as Vika does not interfere with loxP or FRT sites used in these strategies.
2Adaptability or versatility
If rAAV or LVV vectors are used, then cell-type specific expression is achieved, but packaging capacity is limited
Solution Approach 1:
The patent creates a universal HdAd production system using Vika/vox recombination that can accommodate multiple functions: it enables production of HdAd vectors with large packaging capacity (36 kb) while maintaining compatibility with various cell-type specific expression strategies through preservation of loxP and FRT sites.
3Productivity
If helper virus is used for HdAd production, then replication efficiency is improved, but contaminating helper virus increases
Solution Approach 1:
The patent extracts the recombination function from the conventional Cre/loxP or Flp/FRT system and implements it through a separate Vika/vox system. This extraction allows the helper virus to be removed or inactivated after serving its production purpose, as Vika-mediated recombination at vox sites enables selective removal of the helper virus genome while retaining HdAd vectors.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system enables the production of HdAd vectors with high titers and low helper virus contamination, expanding the utility for genetic intersectional strategies and cell-type specific expression of large genes and transgene cassettes not possible with rAAV or LVV.
Implementation Method 1
a Vika-based production system that utilizes a producer cell line expressing Vika recombinase and a helper virus with vox sites, allowing for efficient replication and production of HdAd vectors
Data Source
AI summary
Methods to produce helper dependent adenovirus, and a cell, vector and kit useful in that regard, are provided.