CAR T-cell Persistence via CD28-4-1BB Costimulation
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Solution Overview
Problem
Current approaches for treating B-cell malignancies using genetically modified T cells with chimeric antigen receptors (CARs) face limitations such as limited in vivo expansion and rapid disappearance of CAR+ T cells, leading to disappointing clinical activity.
Innovation Solution
Development of a CAR comprising an antigen binding domain, a transmembrane domain, a costimulatory signaling region, and a CD3 zeta signaling domain, specifically designed to enhance the persistence and expansion of genetically engineered T cells, allowing them to target and eliminate tumor cells effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If genetically modified T cells with CARs are used to treat B-cell malignancies, then tumor targeting capability is improved, but in vivo persistence and expansion of CAR+ T cells deteriorates
Solution Approach 1:
The CAR structure is segmented into distinct functional domains: an extracellular antigen-binding domain (single-chain variable fragment), a transmembrane domain, and an intracellular signaling domain containing costimulatory elements (CD28 and/or 4-1BB) combined with CD3 zeta signaling motifs. This segmentation allows optimization of each domain's function to improve both tumor targeting and T cell persistence
Solution Approach 2:
The CAR is a composite molecular construct combining elements from different immune receptors: the antigen-binding specificity of antibodies, the transmembrane anchoring of T cell receptors, and costimulatory signaling domains from CD28, 4-1BB, and CD3 zeta. This composite structure integrates multiple signaling pathways to enhance T cell activation, survival, and persistence while maintaining tumor targeting
2Measurement precision
If conventional CAR designs are used, then tumor antigen recognition is achieved, but clinical activity and therapeutic effectiveness deteriorate
Solution Approach 1:
The invention modifies critical parameters of the CAR structure, specifically incorporating dual costimulatory signaling domains (CD28 and 4-1BB) combined with CD3 zeta ITAM motifs in a specific configuration. These parameter changes in the signaling domain composition and architecture transform the CAR from a simple antigen recognizer into a potent activator of sustained T cell responses, dramatically improving clinical activity while maintaining antigen recognition precision
Data Source
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AI summary
The present invention provides compositions and methods for treating cancer in a human. The invention includes relates to administering a genetically modified T cell to express a CAR wherein the CAR comprises an antigen binding domain, a transmembrane domain, a costimulatory signaling region, and a CD3 zeta signaling domain.