Truncated EGFR Domain IV Marker for T-Cell Selection and Tracking
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Solution Overview
Problem
Existing immunotherapy strategies using genetically redirected immune cells face challenges due to immunologic rejection of cell products expressing antibiotic selection proteins, necessitating a novel, non-immunogenic selection marker that is not expressed on human lymphocytes and can be recognized by a commercially available antibody for selection, tracking, and depletion.
Innovation Solution
A truncated EGFR (tEGFR) cell surface molecule lacking domain III and retaining domain IV epitope is used, which is inert and anchored through a transmembrane domain, enabling immunomagnetic selection and tracking of genetically modified cells without inducing an immune response, and serving as a suicide gene through antibody-dependent cellular cytotoxicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If antibiotic selection proteins are expressed in genetically redirected immune cells, then selection and purification can be achieved, but immunologic rejection of cell products occurs
Solution Approach 1:
The patent extracts the selection function from antibiotic resistance proteins and relocates it to a truncated EGFR domain IV epitope. This extraction eliminates the harmful immunologic rejection effect while preserving the selection capability through antibody-mediated recognition of the truncated receptor on transduced cells.
Solution Approach 2:
The patent introduces a truncated EGFR domain IV epitope as an intermediary marker between the transduction process and selection. This intermediary is recognized by anti-EGFR antibodies, enabling indirect selection without direct contact with harmful antibiotic proteins, thus resolving the immunologic rejection issue.
2Manufacturing precision
If a selection marker is introduced for tracking and depletion, then cell purification is improved, but the marker must not be expressed on human lymphocytes to avoid immunologic rejection
Solution Approach 1:
The patent applies local quality by modifying only the extracellular domain IV of EGFR while retaining the transmembrane and intracellular domains. This localized modification creates a selection marker with specific properties: it is recognized by anti-EGFR antibodies for selection purposes but lacks the signaling function of wild-type EGFR, making it incompatible with normal human lymphocyte function while enabling precise cell purification.
3Object-affected harmful factors
If EGFR domain III is removed in the truncated receptor, then immunogenicity is reduced, but the epitope recognition by anti-EGFR antibodies must be maintained
Solution Approach 1:
The patent segments the EGFR extracellular domain into functional regions, retaining only domain IV for antibody recognition while removing domain III and other immunogenic regions. This segmentation allows the truncated receptor to maintain epitope recognition functionality through domain IV while eliminating the immunogenic effects of other domains, resolving the contradiction between immunogenicity reduction and antibody recognition maintenance.
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
tEGFR facilitates high-purity enrichment of transduced T cells and effective in vivo tracking, while maintaining T cell function and providing a suicide gene mechanism, overcoming immunologic rejection and enhancing therapeutic efficacy.
Implementation Method 1
a non-immunogenic selection epitope compatible with, for example, immunomagnetic selection... an endogenous cell-surface molecule that is modified or truncated to retain an extracellular epitope recognized by an antibody or functional fragment thereof (e.g., the anti-domain IV antibody provided herein)
Implementation Method 2
serving as a suicide gene through antibody-dependent cellular cytotoxicity
Data Source
AI summary
A truncated EGFR (tEGFR) cell surface molecule and its uses is provided herein. The tEGFR cell surface molecule includes an EGFR domain IV and does not include an EGFR domain III and may be used, inter alia, as an in vivo tracking marker for genetically modified human T cells. Furthermore, the tEGFR cell surface molecule has cellular depletion potential through mediated through specific anti-domain IV EGFR antibodies. Thus, the tEGFR cell surface molecules provided herein may, inter alia, be used as a non-immunogenic selection tool, tracking marker, a depletion tool or a suicide gene for genetically modified cells having therapeutic potential.