Linear Expression Construct for Influenza Virus Production

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Solution Overview

Problem

Current methods for producing influenza virus particles are inefficient and time-consuming, requiring multiple plasmids, bacterial amplification, and selection sequences, which are costly and difficult to automate, limiting the rapid generation of vaccines during epidemics or pandemics.

Innovation Solution

A linear expression construct comprising an RNA polymerase I promoter and termination signal, inserted between an RNA polymerase II promoter and a polyadenylation signal, allows for the direct transfection and expression of viral particles without bacterial amplification or selection sequences, reducing the time needed for vaccine production to a few days.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional plasmid-based methods with bacterial amplification and selection sequences are used, then the production process is well-established and reliable, but the time required for vaccine production is extended to weeks and the process becomes complex and difficult to automate

Engineering Contradiction:
Improveproduction process reliabilityVSAvoidvaccine production time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts and removes the bacterial amplification and selection sequences from the expression construct, using only the essential eukaryotic promoter and termination signal elements. This eliminates the time-consuming bacterial culture and plasmid purification steps while maintaining the core function of viral RNA expression, reducing production time from weeks to days.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The expression construct is designed with all necessary elements (polII promoter, polyadenylation signal, termination signal) pre-assembled in a linear configuration that can be directly transfected into eukaryotic cells. This preliminary preparation of a self-sufficient construct eliminates the need for sequential bacterial amplification and cellular transfection steps, significantly accelerating the production timeline.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple plasmids with amplification and selection sequences are used, then the expression system is robust and well-characterized, but the device complexity and difficulty of automation increase

Engineering Contradiction:
Improveexpression system robustnessVSAvoidproduction process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges all essential expression elements (promoter, termination signal, polyadenylation signal, and viral RNA sequence) into a single linear construct that functions autonomously in eukaryotic cells. This consolidation eliminates the need for multiple separate plasmids and their associated selection markers, simplifying the overall system while maintaining expression robustness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The linear expression construct is designed to be universally applicable to different influenza virus segments by simply replacing the viral RNA sequence portion while keeping the regulatory elements (polII promoter, polyA signal, termination signal) constant. This multi-functional design allows the same basic construct architecture to produce various viral segments without requiring re-engineering of the entire system, reducing complexity.

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

3Quantity of substance

If conventional plasmid methods are used, then sufficient viral RNA can be produced, but the cost and time for vaccine generation during epidemics are excessive

Engineering Contradiction:
Improveviral RNA production量VSAvoidvaccine generation time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent skips the intermediate bacterial amplification step entirely by designing a linear construct that can be directly transfected into eukaryotic cells. This rushing through of the production process eliminates the time-consuming bacterial culture, plasmid purification, and transformation steps, enabling rapid vaccine generation within days rather than weeks while still achieving sufficient viral RNA production levels.

Inventive Principle:
Principle #21Skipping (Rushing through)

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 approach enables fast and efficient production of influenza virus particles, reducing the time and cost associated with traditional methods, facilitating rapid vaccine generation for epidemics and pandemics.

Implementation Method 1

The genomes of these RNA viruses can be unimolecular or segmented, single stranded of (-) polarity. Two essential requirements are shared between these viruses: the genomic RNAs must be efficiently copied into viral RNA, a form which can be used for incorporation into progeny virus particles and transcribed into mRNA which is translated into viral proteins.

Methodology Applied
Scientific EffectTranscription:

Implementation Method 2

Transcripts terminate at sites 15 to 22 bases from the ends of their templates, where oligo(U) sequences act as signals for the addition of poly(A) tracts.

Methodology Applied
Scientific EffectPolyadenylation:

Implementation Method 3

Therefore negative strand RNA viruses encode and carry an RNA-dependent RNA polymerase to catalyze synthesis of new genomic RNA for assembly into progeny and mRNAs for translation into viral proteins.

Methodology Applied
Scientific EffectRNA replication:

Data Source

PatentEP2160462B1Linear constructs for expression of influenza virus
Publication Date: 2017.07.26 NANOTHERAPEUTICS INC
  • EP2160462B1 patent drawingFigure 1a~1b

AI summary

The present invention provides a linear expression construct free of any conventional amplification and/or selection sequences comprising an RNA polymerase I (poll) promoter and a poll termination signal, inserted between a RNA polymerase Il (polll) promoter and a polyadenylation signal useful for the expression of segments of viral RNA, preferably influenza viruses. The inventive construct is useful for efficient and fast production of viral particles, especially for producing vaccine formulations for the treatment of epidemic and/or pandemic diseases.