IL-2 Muteins Selective Receptor Binding
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Solution Overview
Problem
Current IL-2 therapies for cancer are limited by toxic effects and low efficacy due to stimulation of regulatory T cells, which dampen the desired immune stimulation, and existing mutated variants do not offer greater therapeutic efficacy while reducing this stimulation.
Innovation Solution
Development of IL-2 mutated variants that act as partial agonists with a significantly reduced ability to stimulate natural regulatory T cells, maintaining agonistic activity while preventing their expansion, thereby enhancing therapeutic efficacy in tumor therapy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If native IL-2 is used for cancer therapy, then immune response is stimulated, but regulatory T cells are also stimulated which dampen the immune stimulation and cause toxic effects
Solution Approach 1:
The patent applies local quality by creating IL-2 muteins with specific amino acid substitutions that selectively modify the molecule's interaction with different cell types. The mutations (e.g., R38K, F42I, Y45N, E62L, E68V) are strategically positioned to alter binding affinity for the IL-2 receptor, creating a molecule that maintains high affinity for effector T cells while having reduced affinity for regulatory T cells. This localized modification of molecular properties resolves the contradiction by enabling selective immune stimulation without broad activation of suppressive pathways.
Solution Approach 2:
The patent employs parameter changes by systematically varying the amino acid sequence of IL-2 to create multiple mutein variants with different binding characteristics. By changing specific parameters (amino acid residues at positions 38, 42, 45, 62, 68), the patent generates a series of molecules with graded affinities for the IL-2 receptor. This allows selection of muteins that optimize the balance between therapeutic efficacy and reduction of toxic effects, directly addressing the contradiction between stimulating immune response and avoiding regulatory T cell-mediated suppression.
2Power
If mutated variants of IL-2 are designed to increase capacity to signal by high affinity receptor, then signaling in T cells is promoted, but existing variants do not show greater therapeutic efficacy
Solution Approach 1:
The patent applies partial action by creating IL-2 muteins that provide moderate rather than maximal stimulation of the high affinity IL-2 receptor. The amino acid substitutions are designed to enhance, but not maximize, binding affinity - creating a balanced level of signaling that is sufficient to activate effector T cells effectively while avoiding over-stimulation that would trigger compensatory regulatory mechanisms. This partial action approach resolves the contradiction by achieving adequate signaling power without the diminishing returns and potential adverse effects of excessive stimulation.
Data Source
AI summary
The present invention relates to polypeptides which share primary sequence with human IL-2, except for several amino acids that have been mutated. The mutations introduced substantially reduce the ability of these polypeptides to stimulate in vitro and in vivo regulatory T cells (T CD4+CD25+FoxP3+) and make them more effective in the therapy of murine transplantable tumors. Also includes therapeutic uses of these mutated variants, used alone or in combination with vaccines for the therapy of diseases such as cancer or infections where the activity of regulatory T cells (Tregs) is relevant. In another aspect the present invention relates to pharmaceutical compositions comprising as active principle the polypeptides disclosed. Finally, the present invention relates to the therapeutic use of the polypeptides and pharmaceutical compositions disclosed due to their modulating effect of the immune system on diseases like cancer and chronic infectious diseases.