Modified IL-2 Polypeptides for Biased Receptor Binding
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Solution Overview
Problem
Conventional cancer therapies, including chemotherapy and radiation, are limited in their ability to target and eradicate cancer stem cells, which are resistant to these treatments due to their slow growth and chemoresistant nature, leading to inadequate long-term benefits in advanced stage cancers, and IL-2 therapies suffer from severe side effects due to binding with IL-2Rα receptors.
Innovation Solution
Development of modified IL-2 polypeptides incorporating non-naturally encoded amino acids and PEG molecules, which reduce binding to the alpha receptor of Treg cells and promote biased binding to beta and gamma dimers of CD8 cells, enhancing therapeutic application and prognosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cancer therapies (chemotherapy and radiation) are used to target tumor bulk, then the fast-growing tumor cells are eradicated, but cancer stem cells remain resistant and cause relapse
Solution Approach 1:
The patent creates IL-2 polypeptide variants with locally modified properties by introducing specific amino acid substitutions (e.g., position 38, 46, 65) that alter receptor binding characteristics. These localized changes enable the therapeutic to selectively bind to IL-2Rβγ on CD8+ T cells while avoiding IL-2Rα on Treg cells, thereby achieving differential targeting of immune cell subsets to eliminate cancer stem cells without protecting them from conventional therapies.
Solution Approach 2:
The patent segments the IL-2 receptor binding function by designing polypeptides that selectively engage specific receptor subunits (IL-2Rβγ) while excluding others (IL-2Rα). This segmentation of binding specificity allows the therapeutic to activate CD8+ T cells for cancer stem cell elimination without recruiting Treg cells that would suppress the immune response, thereby overcoming the limitation of conventional therapies that cannot distinguish between different cancer cell populations.
2Power
If high dose IL-2 is administered to treat cancer, then anti-tumor activity is enhanced, but severe side effects occur due to binding with IL-2Rα on Treg cells
Solution Approach 1:
The patent introduces specific amino acid substitutions at key positions (38, 46, 65) in the IL-2 polypeptide that locally modify the receptor binding interface. These localized changes create a binding profile that favors IL-2Rβγ on CD8+ T cells while reducing affinity for IL-2Rα on Treg cells, thereby maintaining potent anti-tumor activity through CD8+ T cell activation while minimizing side effects from Treg cell recruitment.
Solution Approach 2:
The patent converts the harmful binding interaction between IL-2 and IL-2Rα on Treg cells into a beneficial selective binding profile. By engineering the IL-2 polypeptide to preferentially bind IL-2Rβγ on CD8+ T cells, the therapy transforms what would be a suppressive interaction into an activating one, harnessing CD8+ T cells to eliminate cancer stem cells while avoiding the immunosuppressive effects of Treg cell activation.
3Power
If conventional IL-2 therapy is used to activate immune cells, then anti-tumor immune response is enhanced, but therapeutic half-life is limited
Solution Approach 1:
The patent creates composite IL-2 polypeptide variants that combine modified amino acid sequences with PEG (polyethylene glycol) molecules through site-specific conjugation. This composite structure maintains the immune activation capability of IL-2 while the PEG moiety provides steric protection and reduces clearance, thereby extending the therapeutic half-life and enabling sustained anti-tumor immune response.
Data Source
AI summary
The present invention provides compositions and methods comprising interleukin-2 (TL-2) polypeptide conjugates. Also described are IL-2 conjugates for the treatment of diseases or conditions including cancer.