Self-Amplifying RNA Construct for Higher Multi-Antigen Expression

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Solution Overview

Problem

Existing self-amplifying RNA vaccines, particularly those based on the alphavirus genome, face challenges in rapid development and large-scale distribution, and there is a need for more efficient expression of antigen proteins to enhance immune response.

Innovation Solution

A novel self-amplifying RNA construct is developed by modifying the 5' untranslated region (UTR), protease cleavage site, and poly(A) tail sequence of an enterovirus-based construct, incorporating a nucleic acid sequence encoding a fusion protein with a non-structural protein, a target protein, and a protease cleavage site, and using a recombinant vector for expression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional mRNA or alphavirus-based self-amplifying RNA constructs are used, then vaccine production can be achieved through cell-free manufacturing, but antigen protein expression levels are insufficient to elicit strong immune response

Engineering Contradiction:
Improveantigen protein expression levelVSAvoidimmune response efficacy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the RNA construct into distinct functional modules: 5' UTR for enhanced translation initiation, non-structural proteins for RNA replication, protease cleavage sites for protein processing, target antigen sequences, and 3' UTR with poly(A) tail for stability. This modular segmentation allows optimization of each component to maximize antigen expression while maintaining self-amplification capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies parameter changes by optimizing specific sequences: modifying the 5' UTR to enhance cap-independent translation, selecting specific protease cleavage sites (2A, 3C, 3CD) for efficient polyprotein processing, and optimizing the 3' UTR and poly(A) tail length for increased RNA stability. These parameter optimizations collectively enhance antigen protein expression levels.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If alphavirus-based self-amplifying RNA constructs are used, then RNA replication capability is achieved, but development and distribution speed is limited

Engineering Contradiction:
Improvevaccine production speedVSAvoidconstruct complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential replication functions by incorporating minimal non-structural proteins (NSPs) required for RNA replication while removing unnecessary viral components. This extraction approach maintains self-amplification capability but reduces overall construct complexity and accelerates development.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary optimization of the RNA construct design, including pre-validated 5' UTR sequences and optimized poly(A) tail lengths, to enable rapid manufacturing. This preliminary action allows for faster scale-up and distribution without compromising replication efficiency.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple antigens are encoded in a single mRNA vaccine, then immune response coverage is enhanced, but antigen expression balance becomes difficult to control

Engineering Contradiction:
Improvemulti-antigen capabilityVSAvoidantigen expression uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent uses protease cleavage sites (2A, 3C, 3CD) as intermediaries between the non-structural proteins and multiple target antigen sequences. These cleavage sites enable precise processing of the polyprotein, ensuring that multiple antigens are produced in controlled proportions and maintaining expression balance across different antigens.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If lower vaccine doses are administered, then safety and reduced side effects are achieved, but antigen expression levels may be insufficient

Engineering Contradiction:
Improvevaccine side effectsVSAvoidantigen protein expression
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements self-service through the self-amplification mechanism where the incorporated non-structural proteins enable the RNA construct to replicate autonomously within host cells. This self-service capability allows low initial doses to generate sufficient antigen expression through in vivo amplification, reducing side effects while maintaining efficacy.

Inventive Principle:
Principle #25Self-service

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

The modified construct significantly increases antigen protein expression, allowing for simultaneous expression of multiple antigens, enhancing immune response and vaccine efficacy.

Implementation Method 1

self-amplifying RNA (saRNA) vaccines have a construct that has RNA polymerase activity in non-structural proteins

Methodology Applied
Scientific EffectRNA replication: Enzyme

Implementation Method 2

a nucleic acid sequence encoding a fusion protein, comprising: a non-structural protein of a self-amplifying virus; a first target protein; and a protease cleavage site

Methodology Applied
Scientific EffectProteolytic cleavage: Enzyme

Data Source

PatentEP4692344A1Self-amplifying RNA construct and use thereof
Publication Date: 2026.02.11 MICROUNI CO LTD
  • EP4692344A1 patent drawingFigure 1a
  • EP4692344A1 patent drawingFigure 1b
  • EP4692344A1 patent drawingFigure 2a~2b

AI summary

The present invention relates to a self-amplifying RNA construct by which the expression of a target protein is optimized. Compared to a conventional mRNA and enterovirus-based self-amplifying RNA, an enterovirus-based optimized self-amplifying RNA according to the present invention increased the expression level of a target protein. In addition, the multiple-antigen self-amplifying RNA expressed one or more target proteins simultaneously, and the expression level thereof was much higher than that of a conventional mRNA. Therefore, the self-amplifying RNA construct according to the present invention can be widely used for vaccines and the like.