Recombinant Flagellin Protein Deletion Reducing Inflammation
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Solution Overview
Problem
Flagellin proteins from pathogenic bacteria have immune adjuvant effects but also pose risks of inflammatory responses and immunological side effects due to their antigenicity and immunogenicity, limiting their use in immunization.
Innovation Solution
A recombinant flagellin protein with deletions in the hypervariable region (amino acids 180-400) is developed to maintain adjuvant activity while reducing antigenicity and immunogenicity, specifically constructed using the genome of Salmonella enterica J341 and expressed using the pET28 vector system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flagellin protein from pathogenic bacteria is used as adjuvant, then immune adjuvant activity is enhanced, but antigenicity and immunogenicity increase causing inflammatory responses and immunological side effects
Solution Approach 1:
The patent extracts and removes the hypervariable region (amino acids 180-400) from the flagellin protein sequence, retaining only the conserved regions that are essential for TLR5 binding and adjuvant activity. This extraction eliminates the regions responsible for high antigenicity while preserving the functional core of the protein.
Solution Approach 2:
The patent applies local quality by making the flagellin protein structure non-uniform through selective deletion. The conserved regions (amino acids 1-179 and 401-561) are retained to maintain adjuvant function, while the hypervariable region is removed to reduce immunogenicity, creating a protein with spatially differentiated functional properties.
2Reliability
If full-length flagellin protein is used, then strong adjuvant activity is achieved, but safety profile deteriorates due to liver toxicity and inflammatory responses
Solution Approach 1:
The patent removes the harmful hypervariable region from the flagellin protein sequence, extracting only the essential conserved regions that provide adjuvant activity. This extraction eliminates the source of liver toxicity and inflammatory responses while retaining the beneficial immunostimulatory function.
Solution Approach 2:
The patent converts the potentially harmful full-length flagellin protein into a beneficial optimized version by removing the hypervariable region. The deletion transforms a protein that causes immunological side effects into one that provides strong adjuvant activity with improved safety, effectively converting harm into benefit through selective removal of problematic regions.
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 recombinant flagellin protein demonstrates reduced antigenicity and immunogenicity, maintaining strong adjuvant activity and showing improved safety profiles, including decreased inflammatory responses and liver toxicity compared to the full-length flagellin protein.
Implementation Method 1
The flagellin protein binds to Toll-like receptors (TLRs) 5, activating the NF-κB pathway and then triggering innate immunity
Data Source
AI summary
The present invention provides an optimized recombinant flagellin protein and preparation and use thereof. The protein is with a deletion in the hypervariable region, said hypervariable region is the region from 180 to 400 amino acid of the flagellin protein, and the proteins include FliCΔ190-278, FliCΔ220-320 or FliCΔ180-400. The method of preparing said protein, comprising introducing a deletion into the hypervariable region of the flagellin protein. First constructed the flagellin protein recombinant plasmid, and then used it as template to construct the flagellin deletion cloning, and expressed and purified. The present invention also provides the use of the recombinant flagellin protein as adjuvant. The recombinant flagellin protein in present invention decreases the potential risks it may have, and decreases its antigenicity and immunogenicity and the inflammatory response induced by it, through deleting its main areas of immunogenicity and antigen activity.