RNA Virus Attenuation via Codon Replacement for Vaccine Stability

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Solution Overview

Problem

Current methods for attenuating RNA viruses for vaccine production are empirical and specific to certain virus types, relying on random gene mutations or unnatural conditions, leading to genetic instability and the risk of reversion to a pathogenic phenotype, and lack a universal approach.

Innovation Solution

The attenuation of RNA viruses is achieved by modifying their mutational robustness through codon replacement, placing them in a precarious region of their genetic sequence space where mutations become lethal, using synonymous or non-synonymous codon substitutions that differ by only one nucleotide from a STOP codon, without affecting protein sequence or replication capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If random gene mutation or passages in unnatural conditions are used to attenuate RNA viruses, then the virus is attenuated, but genetic instability and risk of reversion to pathogenic phenotype increase

Engineering Contradiction:
Improveattenuation stabilityVSAvoidgenetic stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the nucleotide sequence parameters at codon positions while preserving amino acid sequences through synonymous codon substitutions. This creates a stable attenuated state by altering the genetic code's robustness properties without changing the protein product, thereby preventing reversion while maintaining attenuation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the genome into individual codon positions and selectively modifies specific codons (particularly at positions 1, 2, and 3) to reduce mutational robustness. This segmented approach allows precise control over which genetic positions contribute to attenuation stability versus pathogenicity risk.

Inventive Principle:
Principle #1Segmentation

2Reliability

If conventional empirical methods are used for RNA virus attenuation, then attenuation is achieved, but the method lacks universality and is specific to certain virus types

Engineering Contradiction:
Improveattenuation effectivenessVSAvoidmethod universality
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal attenuation method that can be applied to any RNA virus by modifying codon sequences. The approach uses general principles of codon position modification and mutational robustness reduction that are applicable across different virus families, eliminating the need for virus-specific empirical optimization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes fundamental parameters of the genetic code (codon-nucleotide relationships) rather than relying on virus-specific characteristics. By targeting universal properties of RNA replication and codon structure, the method achieves broad applicability across all RNA viruses while maintaining reliable attenuation.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If codon replacement is used to reduce mutational robustness, then the virus becomes hyper-sensitive to mutation, but the risk of introducing harmful factors increases

Engineering Contradiction:
Improvemutation sensitivityVSAvoidpotential harmful mutations
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the naturally high mutation rate of RNA viruses, which normally benefits viral evolution and pathogenicity, into a beneficial force for attenuation. By reducing mutational robustness through codon modification, the high mutation rate now generates lethal mutations rather than beneficial ones, turning the virus's evolutionary strength into its weakness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the threshold parameter for mutation tolerance by modifying codon sequences. This shifts the system from a state where mutations are tolerated (robust) to a state where mutations are lethal (sensitive), thereby converting the harmful potential of mutations into a beneficial attenuation mechanism.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3250684B1RNA virus attenuation by alteration of mutational robustness and sequence space
Publication Date: 2019.08.28 INST PASTEUR
  • EP3250684B1 patent drawingFigure 1
  • EP3250684B1 patent drawingFigure 2
  • EP3250684B1 patent drawingFigure 3

AI summary

The application generally relates to the attenuation of a RNA virus or of a clone thereof and involves the alteration of sequence space, more particularly the reduction, of mutational robustness of said RNA virus or clone. The means of the application are more particularly dedicated to the attenuation of an infectious RNA virus or clone, for the production of immunogenic composition or vaccine. More particularly, the means of the application involve the replacement of codon(s) by different codon(s), which is(are) selected to differ by only one nucleotide from a codon STOP, more particularly by different but synonymous codon(s), which is(are) selected to differ by only one nucleotide from a codon STOP.