Modified Lipopolysaccharide Glycoform for Antibiotic Decoy

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Solution Overview

Problem

Gram-negative bacteria, such as E. coli, have a permeability barrier in their outer membrane that restricts the access of antibiotics like vancomycin, limiting their effectiveness due to the shielding by lipopolysaccharide (LPS), which is also inherently toxic and requires detoxification, reducing its immunostimulatory properties.

Innovation Solution

Genetic engineering of E. coli to express a mutant O-antigen ligase (waaL15) that modifies LPS to create a glycoform (LPS*) with increased vancomycin resistance by displaying antibiotic-binding sites at the cell surface, allowing for enhanced immunostimulation while reducing endotoxicity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LPS is used to form the outer membrane barrier, then antibiotic access is restricted and bacterial protection is improved, but LPS endotoxicity increases and immunostimulatory properties are enhanced excessively

Engineering Contradiction:

Improveantibiotic barrier functionVSAvoidLPS endotoxicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies detoxification to eliminate the harmful endotoxic properties of LPS while preserving its beneficial barrier function and immunostimulatory capabilities. The detoxified LPS-PG molecule converts the harmful endotoxic effect into a beneficial therapeutic agent that can safely activate immune responses without causing hyper-inflammatory reactions.

Inventive Principle:

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

Solution Approach 2:

The patent creates a composite LPS-PG molecule that combines lipopolysaccharide with peptidoglycan cell wall fragments. This composite structure integrates two different bacterial components into a single molecule that can simultaneously engage multiple immune pathways (TLR4 for LPS and NOD1/NOD2 for PG) while the detoxification process removes the harmful endotoxic properties.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If LPS is detoxified to reduce endotoxicity, then harmful effects are reduced, but immunostimulatory properties are also reduced

Engineering Contradiction:

ImproveendotoxicityVSAvoidimmunostimulatory properties

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The detoxified LPS-PG composite molecule compensates for the reduced immunostimulatory properties of detoxified LPS by incorporating peptidoglycan fragments. This composite structure provides alternative immunostimulatory pathways through NOD1 and NOD2 receptors, maintaining overall immunogenicity while the LPS component remains detoxified and safe.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent merges LPS and PG into a single coupled molecule, allowing both activators to stimulate their associated pathways synergistically. The direct coupling enables the molecule to activate both TLR4 (via LPS) and NOD1/NOD2 (via PG) pathways simultaneously, creating a synergistic immune response that compensates for the reduced potency of individual detoxified components.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If vancomycin binding sites are displayed at the cell surface, then vancomycin resistance is improved, but the antibiotic can still reach its true target if the barrier is insufficient

Engineering Contradiction:

Improvevancomycin resistanceVSAvoidantibiotic access

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The modified LPS molecule acts as an intermediary that binds vancomycin at the cell surface, preventing the antibiotic from reaching its true target (peptidoglycan synthesis enzymes). This intermediary binding site serves as a decoy that intercepts vancomycin before it can access its actual target, providing effective resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent exploits the high affinity of vancomycin for its target by creating a modified LPS that presents similar binding motifs. This converts the antibiotic's specificity into a benefit for the bacterium, as the same molecular recognition features that make vancomycin effective also enable the LPS to bind and sequester the drug.

Inventive Principle:

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

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 LPS* molecule confers vancomycin resistance by acting as a molecular decoy, titrating vancomycin away from the true drug target and maintaining immunostimulatory properties, potentially improving vaccine adjuvant delivery and immune response activation.

Implementation Method 1

Genetic engineering of E. coli to express a mutant O-antigen ligase (waaL15) that modifies LPS to create a glycoform (LPS*) with increased vancomycin resistance

Methodology Applied

Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 2

The modified LPS* molecule confers vancomycin resistance by acting as a molecular decoy, titrating vancomycin away from the true drug target

Methodology Applied

Scientific EffectMolecular binding: Adsorption

Data Source

PatentUS10864266B2Modified lipopolysaccharide glycoform and method of use

Publication Date: 2020.12.15 THE TRUSTEES OF PRINCETON UNIV

AI summary

The present disclosure generally relates to genetic engineering of bacteria. More particularly, the present disclosure describes genetic engineering of E. coli to create mutant O-antigen ligase, as well as novel lipopolysaccharide molecules resulting from that genetic engineering. Methods for using those novel molecules are also described.