Logic-Gated CAR Construct Reduces Off-Tumor Toxicity
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Solution Overview
Problem
Current immunotherapeutic agents, including chimeric antigen receptors (CARs), often result in 'on-target off-tumor' toxicity due to targeting single antigens, leading to damage of normal tissues and reduced specificity in cancer treatment.
Innovation Solution
Development of 'logic-gated' CAR pairs that modulate expression based on specific patterns of antigen presence, allowing T cells to trigger only when both target antigens are present, using a nucleic acid construct encoding activating and inhibitory CARs with distinct spacer domains and retention signals to achieve precise targeting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-antigen CAR targeting is used, then treatment simplicity is maintained, but on-target off-tumor toxicity increases
Solution Approach 1:
The patent divides the targeting function into multiple independent CAR components, each recognizing a different antigen. Instead of using a single CAR that targets one antigen, the invention employs multiple CARs (e.g., CAR1 targeting antigen1, CAR2 targeting antigen2) that work together through logical gating mechanisms. This segmentation allows the system to distinguish tumor cells (expressing multiple antigens) from normal cells (expressing only one antigen), thereby reducing off-tumor toxicity while maintaining manageable complexity through modular design.
2Object-affected harmful factors
If multiple CARs are co-expressed to improve targeting specificity, then off-tumor toxicity is reduced, but expression control complexity increases
Solution Approach 1:
The patent merges multiple CAR expression control functions into a unified logical gating system. By implementing AND-gate or OR-gate logic where multiple CARs are co-expressed and integrated through shared signaling pathways, the system achieves coordinated control of multiple antigens. This merging approach allows complex multi-antigen targeting to be managed through integrated logical operations rather than independent control mechanisms, reducing overall system complexity while maintaining high specificity.
3Measurement precision
If logic-gated CAR pairs with distinct spacers are used, then targeting precision is improved, but CAR structure complexity increases
Solution Approach 1:
The patent applies local quality by introducing spacers with distinct properties (different lengths, compositions, or functional characteristics) at specific locations within the CAR structure. These localized variations in spacer properties enable differential control of CAR conformation, stability, and signaling activation. For example, shorter spacers may promote tight clustering for AND-gate activation, while longer spacers may allow independent activation for OR-gate logic. This localized differentiation achieves high targeting precision without requiring complete redesign of the entire CAR structure, maintaining modularity and managing complexity.
Data Source
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Figure 2
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AI summary
The present invention provides a nucleic acid construct comprising the following structure: A – X – B in which X is a nucleic acid sequence which encodes a cleavage site; and A and B are nucleic acid sequences encoding a first and a second chimeric antigen receptor (CAR), each CAR comprising: (i) an antigen-binding domain; (ii) a spacer (iii) a trans-membrane domain; and (iv) an endodomain wherein the antigen binding domains of the first and second CARs bind to different antigens, wherein the spacer of the first CAR is different to the spacer of the second CAR and wherein one of the first or second CARs is an activating CAR comprising an activating endodomain and the other CAR is an inhibitory CAR comprising a ligation-off inhibitory endodomain; and wherein: (a) the first and/or second CAR comprises an intracellular retention signal; and/or (b) the signal peptide of the first or second CAR comprises one or more mutation(s) such that it has fewer hydrophobic amino acids.