Fusion Polypeptide Vaccine Using Toxin A/B Binding Domains
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Solution Overview
Problem
There is a need for an effective vaccine against Clostridium difficile-associated diarrhea (CDAD) caused by toxins A and B, as existing treatments are inadequate, particularly for high-risk patients, and current vaccine candidates face stability and yield issues.
Innovation Solution
Development of an isolated polypeptide comprising 19 repeating units of toxin A and 23 repeating units of toxin B, fused via a linker, for use in a vaccine formulation that can be administered with or without adjuvants, targeting the receptor binding domains to induce protective antibodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vaccine targeting both toxin A and toxin B is developed, then protection against CDAD is improved, but the complexity of the vaccine formulation increases
Solution Approach 1:
The patent combines the receptor binding domains of toxin A and toxin B into a single fusion polypeptide structure. This merging approach allows the vaccine to elicit antibodies against both toxins simultaneously, providing comprehensive protection while simplifying the overall vaccine formulation compared to using separate toxin components.
Solution Approach 2:
The vaccine design segments the full-length toxins by using only the receptor binding domains (RBDs) of toxin A and toxin B. This segmentation retains the essential immunogenicity needed for protection while removing unnecessary portions of the toxin structure, thereby reducing formulation complexity and potential adverse effects from non-essential toxin regions.
2Ease of manufacture
If the polypeptide structure is simplified for easier manufacture, then manufacturing ease is improved, but the ability to induce neutralizing antibodies may be reduced
Solution Approach 1:
The patent extracts only the essential receptor binding domains from the full-length toxins A and B. This extraction focuses the vaccine on the critical immunogenic regions that elicit neutralizing antibodies, while removing non-essential sequences that would complicate manufacturing. The RBDs contain the key epitopes needed for antibody induction, making this extraction both manufacturable and effective.
Solution Approach 2:
The vaccine design applies local quality by concentrating the immunogenic functionality in specific regions (the RBDs) rather than using entire toxin molecules. Each RBD is optimized to maintain its antibody-inducing capability while being structurally simplified for easier production. The linker region provides local flexibility to ensure proper folding and presentation of both RBDs.
3Reliability
If a fusion polypeptide is used to target both toxins, then vaccine efficacy is improved, but the structural complexity of the polypeptide increases
Solution Approach 1:
The patent incorporates a flexible linker region between the toxin A and toxin B RBDs in the fusion polypeptide. This dynamic element allows the two RBD domains to adopt appropriate spatial orientations and maintain proper folding, ensuring both retain their ability to induce neutralizing antibodies. The flexibility compensates for the structural complexity introduced by the fusion, allowing each domain to function independently while being part of a unified vaccine molecule.
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 polypeptide vaccine effectively induces toxin-neutralizing antibodies, providing long-term protection against CDAD, especially in high-risk populations, and can be administered through various routes, including intramuscular and mucosal delivery.
Implementation Method 1
The polypeptide vaccine effectively induces toxin-neutralizing antibodies, providing long-term protection against CDAD
Data Source
AI summary
This present invention provides C-TAB.G5 and C-TAB.G5.1 isolated polypeptides comprising the receptor binding domains of C. difficile toxin A and toxin B as set forth in the amino acid sequences of SEQ ID NO: 2 and SEQ ID NO: 4. The C-TAB.G5 and C-TAB.G5.1 isolated polypeptides may be used to neutralize toxic effects of C. difficile toxin A and/or toxin B.