Modified Ribotoxin Epitopes Reduce Immunogenicity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wild-type ribotoxins like α-sarcin, clavin, gigantin, and restrictocin are highly immunogenic, leading to unwanted immune responses when used therapeutically or prophylactically, limiting their efficacy due to their strong binding to human MHC class II molecules and eliciting significant T cell responses.
Innovation Solution
Modified ribotoxin epitopes with specific mutations at critical amino acid positions, such as D9, Q10, P13, T15, N16, Y18, K139, E140, or Q142, reduce binding to human MHC class II and elicit a reduced T cell response, as measured by in vitro assays, thereby minimizing immunogenicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wild-type ribotoxins are used therapeutically, then they can inhibit protein synthesis and kill target cells, but they elicit strong T cell responses and bind to human MHC class II molecules, causing unwanted immune responses
Solution Approach 1:
The patent applies parameter changes by introducing specific amino acid substitutions at positions 10, 16, and 139 of the ribotoxin sequence. These parameter changes at critical epitope regions reduce the toxin's binding affinity to human MHC class II molecules while preserving its ribonuclease activity and ability to inhibit protein synthesis in target cells
Solution Approach 2:
The patent applies local quality by making targeted modifications only at specific amino acid positions (10, 16, and 139) that correspond to T cell epitopes, rather than altering the entire molecule. This localized approach reduces immunogenicity at the epitope level while maintaining the overall structure and catalytic function of the ribotoxin
2Strength
If wild-type ribotoxins are used, then they maintain full ribonuclease activity, but they exhibit high binding to human MHC class II molecules, limiting therapeutic application
Solution Approach 1:
The patent introduces specific amino acid substitutions at positions 10, 16, and 139 that change the molecular parameters of the epitope regions. These changes reduce MHC class II binding affinity while preserving the catalytic triad (His50, Glu96, His137) and overall fold necessary for ribonuclease activity
3Object-affected harmful factors
If ribotoxins are modified to reduce immunogenicity, then T cell response is reduced, but there may be loss of ribonuclease activity
Solution Approach 1:
The patent applies local quality by restricting modifications to specific amino acid positions (10, 16, and 139) that are outside the catalytic triad and active site. The substitutions at these localized epitope positions reduce T cell recognition while the core catalytic residues (His50, Glu96, His137) and structural elements remain unchanged, preserving ribonuclease activity
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 ribotoxin epitopes exhibit reduced immunogenicity and T cell stimulation, potentially enhancing their therapeutic or prophylactic applications by minimizing adverse immune reactions.
Implementation Method 1
Without intending to be bound by any theory or mechanism, it is believed that the modified ribotoxin epitopes disclosed in this application possess reduced binding to human MHC class II and/or elicit a reduced T cell response as compared to the corresponding wild type ribotoxin epitopes
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
The present application relates to modified T cell epitopes derived from fungal ribotoxins, including a-sarcin, clavin, gigantin, mitogillin, and restrictocin, as well as modified ribotoxin molecules comprising one or more of the modified epitopes. The modified ribotoxin molecules inhibit protein synthesis, like the wild type ribotoxins, but exhibit reduced immunogenicity as compared to the corresponding wild type ribotoxin. Another aspect relates to a fusion protein which comprises a modified ribotoxin fused or conjugated or otherwise linked to a targeting molecule that is effective for binding a target of interest. Another aspect relates to the use of the modified ribotoxin or fusion protein for treating or managing a disease or condition.