Modified Host Cells for Stable Pseudomonas Antigen Production

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Solution Overview

Problem

Current vaccine development for Pseudomonas infections faces challenges in producing effective vaccines in high quantities while ensuring safety and stability, particularly in efficiently expressing Pseudomonas-specific antigens in host cells.

Innovation Solution

Modified prokaryotic host cells are engineered to include nucleic acids encoding glycosyltransferases, wzy polymerases, oligosaccharyl transferases, and carrier proteins with N-glycosylation consensus sequences, allowing for the production of bioconjugates comprising Pseudomonas antigens, such as the O antigen of Pseudomonas aeruginosa, by integrating these genes into the host cell genome, thereby enhancing antigen expression and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plasmid-based expression systems are used to produce Pseudomonas antigens, then antigen production can be achieved, but plasmid loss and instability occur during large-scale fermentation

Engineering Contradiction:
Improveplasmid stabilityVSAvoidlarge-scale fermentation yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges the antigen production function with the host cell genome by integrating the rfb cluster and carrier protein genes into chromosomal loci. This integration eliminates plasmid-based expression systems and their associated instability issues, allowing reliable large-scale fermentation without plasmid loss while maintaining high antigen production yields

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If antibiotic selection is used to maintain plasmid expression, then antigen expression can be maintained, but safety risks and regulatory concerns increase

Engineering Contradiction:
Improveantigen expression maintenanceVSAvoidantibiotic contamination risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and eliminates the antibiotic selection requirement by integrating antigen production genes into the host genome. The integrated system maintains stable expression through chromosomal inheritance without requiring antibiotic pressure, thereby removing the source of antibiotic contamination risk while preserving reliable antigen expression

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the expensive and harmful antibiotic selection system with a self-sustaining chromosomal integration system. The integrated genes are maintained through normal cell division without requiring continuous antibiotic addition, eliminating the need for this harmful auxiliary system

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If chemical conjugation methods are used to produce bioconjugates, then antigen-carrier proteins can be produced, but production complexity and cost increase

Engineering Contradiction:
Improvebioconjugate production simplicityVSAvoidconjugation process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent enables the host cell to self-assemble the bioconjugate structure through native glycosylation machinery. The carrier protein with N-glycosylation sites is automatically modified with Pseudomonas O-antigen polysaccharides by the cell's endogenous enzymes, eliminating the need for external chemical conjugation processes and their associated complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces an intermediary biological system (the host cell's glycosylation machinery) that naturally performs the conjugation function. Instead of using chemical reagents to link antigen and carrier protein, the cell's enzymatic system mediates the formation of stable glycosidic bonds, simplifying the manufacturing process

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If heterologous gene integration is performed to produce Pseudomonas antigens, then antigen expression is enhanced, but genetic stability challenges arise

Engineering Contradiction:
Improveantigen expression levelVSAvoidgenetic stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent merges the heterologous rfb cluster and carrier protein genes into stable chromosomal loci through integration. This integration ensures the genes are inherited stably with the host genome during cell division, maintaining both high expression levels and genetic stability across fermentation generations

Inventive Principle:
Principle #5Merging (Combining)

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 the large-scale fermentation of stable bioconjugates, reducing the risk of plasmid loss and antibiotic selection, leading to higher yields and safer vaccine production with improved antigen expression and stability, addressing the limitations of existing vaccine production methods.

Implementation Method 1

a nucleic acid that encodes a carrier protein comprising an N-glycosylation consensus sequence D/E - X - N - X- S/T wherein X is any amino acid except proline

Methodology Applied
Scientific EffectN-glycosylation: Chemical Bonding

Implementation Method 2

a nucleic acid that encodes a glycosyltransferase derived from an rfb cluster of Pseudomonas

Methodology Applied
Scientific EffectGlycosyltransferase catalysis: Enzyme

Implementation Method 3

a nucleic acid that encodes a wzy polymerase, wherein said nucleic acid encodes a protein having about or at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity to SEQ ID NO:3

Methodology Applied
Scientific EffectPolymerization:

Data Source

PatentEP3711776B1Modified host cells and uses thereof
Publication Date: 2023.01.11 GLAXOSMITHKLINE BIOLOGICALS SA
  • EP3711776B1 patent drawingFigure 1
  • EP3711776B1 patent drawingFigure 2
  • EP3711776B1 patent drawingFigure 3A~3B

AI summary

Described herein are modified host cells useful in the production of bioconjugates that can be used to vaccinate subjects against infection with Pseudomonas. The genomes of the modified host cells described herein comprise genes that encode proteins involved in glyosylation of proteins as well as genes specific to the production of Pseudomonas-specific antigens.