Recombinant C. Difficile Fusion Antigens for Stronger Neutralization
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Solution Overview
Problem
Current therapies for Clostridium difficile infection (CDI) are inadequate, with antibiotics showing decreasing efficacy and existing vaccines based on C-terminal repeating units of Toxins A and B being poorly immunogenic or producing insufficient neutralizing antibodies.
Innovation Solution
Development of recombinant antigens comprising a 'scaffold' region from Toxin A and/or B, combined with C-terminal repeating units, which induce a potent toxin-neutralizing immune response and are readily manufactured in large quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If vaccines are based on C-terminal repeating units of Toxins A and B, then manufacturing is simplified, but immunogenicity is poor and neutralizing antibody production is insufficient
Solution Approach 1:
The patent combines the C-terminal repeating units (which are easy to manufacture) with the scaffold region (which provides immunogenicity) into a single fusion protein antigen. This merging resolves the contradiction by integrating both the manufacturable component and the immunogenic component into one molecule, achieving both ease of manufacture and high immunogenicity simultaneously.
2Reliability
If antibiotics are used for CDI treatment, then initial efficacy is observed, but efficacy decreases over time
Solution Approach 1:
The patent converts the harmful toxins produced by C. difficile into beneficial therapeutic agents by using them as antigens in a vaccine. The scaffold region and repeating units from the toxins are used to stimulate the immune system to produce neutralizing antibodies, transforming the pathogen's weapon into a protective tool that provides long-lasting immunity rather than temporary antibiotic suppression.
3Reliability
If recombinant antigens include scaffold region from Toxin A and B, then toxin-neutralizing immune response increases 10-100 fold, but antigen complexity increases
Solution Approach 1:
The patent segments the toxin structure into two functional domains: the scaffold region (residues 1-1849) that provides immunogenicity and structural framework, and the C-terminal repeating units (residues 1850-2710) that provide toxin-neutralizing epitopes. This segmentation allows the complex antigen to be rationally designed with distinct functional modules, making the complexity manageable and the manufacturing process straightforward through recombinant expression.
Data Source
AI summary
The present application relates to recombinant Clostridium difficile antigens based on a fusion protein that consists of or comprises a first amino acid sequence and a second amino acid sequence, wherein: a) the first amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of residues 1500-1850 of a C. difficile Toxin A sequence or residues 1500-1851 of a C. difficile Toxin B sequence; and b) the second amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of a long repeat unit located within amino acid residues 1851-2710 of a C. difficile Toxin A sequence or within amino acid residues 1852-2366 of a C. difficile Toxin B sequence; though with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2710 of a C. difficile Toxin A and with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2366 of a C. difficile Toxin B. Also provided is the use of said antigens for the prevention/treatment/suppression of Clostridium difficile infection (CDI), together with methods for generating said antigens, methods for generating antibodies that bind to said antigens, and the use of said antibodies for the prevention/treatment/suppression of CDI.