Meningococcus OMV Antigen Overexpression via Genetic Modification
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Solution Overview
Problem
Current meningococcal vaccines based on outer membrane vesicles (OMVs) face limitations in antigen expression levels and immunogenicity, which can impact their efficacy in eliciting cross-protective antibody responses.
Innovation Solution
The development of meningococcal strains that over-express specific antigens such as NadA and NHBA through genetic modifications, including promoter replacement, gene addition, and repressor knockout, to increase antigen levels in OMVs, resulting in higher immunogenicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If genetic modifications are made to over-express antigens NadA and NHBA in meningococcus, then antigen expression levels and immunogenicity are improved, but the complexity of the production process increases
Solution Approach 1:
The patent applies parameter changes by modifying genetic parameters (promoter strength, gene dosage, repressor presence) to control antigen expression levels. Specifically, it uses promoter replacement to increase transcriptional activity, gene addition to increase copy number, and repressor knockout to remove negative regulation, thereby achieving high-level over-expression of NadA and NHBA antigens in the meningococcus strain
Solution Approach 2:
The patent employs preliminary action by pre-modifying the meningococcus strain with multiple genetic changes (promoter replacement, gene addition, repressor knockout) before OMV production. These preliminary genetic modifications ensure that the bacteria are primed to over-express the desired antigens, so that when OMVs are produced, they already contain high levels of immunogenic proteins without requiring additional post-production manipulation
2Reliability
If multiple genetic modifications are introduced to increase antigen levels, then immunogenicity is improved, but the difficulty of strain development increases
Solution Approach 1:
The patent applies segmentation by dividing the strain development process into distinct, manageable genetic modification steps: (1) promoter replacement to enhance basal expression, (2) gene addition to increase copy number, and (3) repressor knockout to eliminate negative regulation. Each modification can be performed and validated separately, making the overall complex process more controllable and reproducible
Solution Approach 2:
The patent achieves universality by creating a modular genetic modification strategy that can be applied to different antigen targets. The combination of promoter replacement, gene addition, and repressor knockout forms a universal platform that can be adapted to over-express various meningococcal antigens, not just NadA and NHBA, making the approach broadly applicable to vaccine development
Data Source
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AI summary
A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant of an antigen of interest.