Recombinant CSFV E2 Protein Deletion for Serological Differentiation

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Solution Overview

Problem

Current classical swine fever virus (CSFV) vaccines do not allow for differentiation between infected and vaccinated animals, leading to challenges in trade restrictions and control of CSFV outbreaks, and existing DIVA vaccines have limitations in efficacy and specificity, especially in regions where other pestiviruses circulate.

Innovation Solution

A recombinant CSFV with a deletion of at least one amino acid in the TAVSPTTLR domain of the E2 protein is developed, which enables serological differentiation between infected and vaccinated animals, using a peptide-based diagnostic test, and is designed to be specific to CSFV without cross-reactivity with other pestiviruses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a CSFV vaccine is used to provide immunity, then protection against virulent CSFV is achieved, but serological differentiation between infected and vaccinated animals becomes impossible

Engineering Contradiction:
Improveimmunity efficacyVSAvoidserological differentiation accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent extracts the TAVSPTTLR epitope sequence from the E2 protein of the vaccine virus by introducing a deletion or substitution mutation. This allows the vaccine to maintain immunogenicity while creating a detectable difference between vaccinated and infected animals through serological testing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mutation is introduced at a specific local region (the TAVSPTTLR epitope domain) of the E2 protein rather than altering the entire protein structure. This localized modification preserves overall vaccine efficacy while enabling differentiation through specific antibody response detection.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If existing DIVA vaccines are used to enable differentiation, then serological differentiation is possible, but cross-reactivity with other pestiviruses occurs reducing specificity

Engineering Contradiction:
Improveserological differentiation accuracyVSAvoidcross-reactivity with other pestiviruses
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent targets a specific local region (TAVSPTTLR epitope) within the E2 protein that is conserved among CSFV strains but variable in other pestiviruses. This localized approach enables specific detection of CSFV infection without cross-reactivity with BVDV or BDV.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent exploits sequence parameter differences in the TAVSPTTLR region among pestivirus species. By designing the vaccine and diagnostic test around this specific sequence variable, the system achieves high specificity for CSFV while maintaining the ability to differentiate vaccinated from infected animals.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the TAVSPTTLR domain is modified to enable differentiation, then DIVA capability is achieved, but immune response efficacy may be reduced

Engineering Contradiction:
Improveserological differentiation accuracyVSAvoidimmune response efficacy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The mutation is confined to the TAVSPTTLR epitope domain while preserving the rest of the E2 protein structure and other immunodominant regions. This localized modification maintains overall immunogenicity and protective immunity while enabling serological differentiation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses subtle parameter changes (deletion or substitution of specific amino acids in TAVSPTTLR) rather than drastic modifications. These minimal changes are sufficient to prevent antibody cross-reactivity with the vaccine strain while preserving the immunogenicity needed for protective immunity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2382307B1Recombinant classical swine fever virus (CSFV) comprising a modified e2 protein and methods for generating said recombinant CSFV.
Publication Date: 2015.07.15 INTERVET INT BV
  • EP2382307B1 patent drawingFigure 1
  • EP2382307B1 patent drawingFigure 2
  • EP2382307B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a recombinant classical swine fever virus (CSFV). A preferred recombinant CSFV comprises a deletion of at least one amino acid in a "TAVSPTTLR" domain of the E2 protein. The invention further relates to a vaccine comprising the recombinant CSFV, a method for generating a recombinant CSFV, and use of a recombinant CSFV.