Bile Acid-Conjugated Antigens for Endosomal Escape and Stability

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Solution Overview

Problem

Polypeptide antigens often fail to elicit strong and long-lasting immune responses, and mRNA-based vaccines face stability and refrigeration challenges, hindering their global deployment.

Innovation Solution

Covalently conjugating polypeptide antigens to bile acid-peptide moieties, including a nuclear localization signal, to enhance immunogenicity and stability, facilitating improved endosomal escape and antigen presentation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polypeptide antigens are used as subunit vaccines, then safety is improved, but immune response strength deteriorates

Engineering Contradiction:
ImprovesafetyVSAvoidimmune response strength
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent conjugates polypeptide antigens to bile acid moieties to create composite structures. This combination leverages the safety of polypeptide antigens while the bile acid component enhances immunogenicity, producing a composite vaccine that achieves both safety and strong immune response. The bile acid-peptide conjugate forms a new material with properties superior to the individual components.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If mRNA-based vaccines are used, then immunogenicity is improved, but stability deteriorates

Engineering Contradiction:
ImproveimmunogenicityVSAvoidstability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameters of the antigen by conjugating bile acid moieties to polypeptide antigens. This modification alters the physical and chemical properties of the antigen, enhancing its stability profile while maintaining or improving its immunogenicity. The conjugation changes parameters such as thermal stability and structural integrity without sacrificing immune response capability.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If polypeptide antigens are conjugated to bile acid-peptide moieties, then immunogenicity is improved, but manufacturing complexity increases

Engineering Contradiction:
ImproveimmunogenicityVSAvoidmanufacturing complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent incorporates the bile acid moiety with the peptide sequence (including NLS) as a pre-formed unit before conjugation to the antigen. This preliminary assembly simplifies the manufacturing process by reducing the number of separate steps required. The bile acid-peptide conjugate is prepared in advance, making the final antigen conjugation step more straightforward and manageable.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4262876B1Covalently modified antigens for improved immune response and/or stability
Publication Date: 2026.02.25 DEFENCE THERAPEUTICS INC
  • EP4262876B1 patent drawingFigure 1A~1B
  • EP4262876B1 patent drawingFigure 1C~1D
  • EP4262876B1 patent drawingFigure 1E~1F

AI summary

Covalently modified polypeptide antigens having improved immunogenicity and/or stability, as well as compositions, cells, and methods relating thereto, are described herein. Polypeptide antigens are covalently conjugated to a one or more of steroid acid moieties to improve their stability and/or to trigger improved cellular immunity, or improved cellular and humoral immunity, against the antigen upon administration to a subject. The steroid acids include bile acids and bile acid analogs that enhance endocytosis and/or endosomal escape of endosomally trapped cargoes by potentiating enzymatic cleavage of sphingomyelin to ceramide within endosomal membranes. The steroid acid moieties may be pre-conjugated to a peptide, and the steroid acid-peptide moiety subsequently conjugated to the polypeptide antigen. The peptide may comprise one or more domains that impart an additional functionality to the modified polypeptide antigen.