CAR T Cell Spacer Length Tuning for In Vivo Tumor Recognition
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Solution Overview
Problem
Existing chimeric antigen receptor designs for T cells do not reliably translate superior in vitro function into improved in vivo therapeutic activity for cancer treatment, necessitating the identification of key elements for enhanced survival and efficacy.
Innovation Solution
A chimeric receptor polypeptide with a specific spacer length of 12 amino acids, comprising a ligand binding domain, transmembrane domain, and intracellular signaling domain, customized for optimal tumor recognition and enhanced T cell proliferation and cytokine production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chimeric receptor designs are optimized for superior in vitro function, then T cell activation and cytotoxicity improve in laboratory settings, but the translation to improved in vivo therapeutic activity remains uncertain and inconsistent
Solution Approach 1:
The patent systematically varies the spacer length parameter (testing lengths of 5, 12, 20, 27, and 34 amino acids) to optimize chimeric receptor function. This parameter change approach allows identification of the specific spacer length (12 amino acids) that translates in vitro performance to in vivo therapeutic efficacy, resolving the contradiction between laboratory optimization and clinical translation.
Solution Approach 2:
The patent employs a modular chimeric receptor design where the spacer region can be dynamically adjusted to different lengths. This dynamic adaptability enables the same receptor framework to be optimized for different in vivo requirements while maintaining in vitro functionality, bridging the gap between laboratory and clinical performance.
2Productivity
If the spacer length in chimeric receptors is increased to improve T cell activation, then in vitro cytotoxicity may improve, but in vivo therapeutic activity does not consistently improve
Solution Approach 1:
The patent identifies that extremely short spacers (5 amino acids) or excessively long spacers (34 amino acids) fail to provide optimal in vivo therapy, despite varying in vitro performance. The optimal spacer length of 12 amino acids balances T cell activation with in vivo therapeutic efficacy, resolving the contradiction between proliferation and reliable therapeutic activity.
3Manufacturing precision
If chimeric receptor components are customized for optimal in vitro function, then laboratory performance improves, but reproducibility of improved in vivo activity across different designs remains uncertain
Solution Approach 1:
The patent establishes that precise control of spacer length (specifically 12 amino acids) is critical for translating design precision to reliable in vivo outcomes. This parameter standardization enables different chimeric receptor designs to consistently achieve improved therapeutic activity across preclinical and clinical settings.
Data Source
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AI summary
The present invention provides nucleic acids, vectors, host cells, methods and compositions to confer and/or augment immune responses mediated by cellular immunotherapy, such as by adoptively transferring CD8+ central memory T cells or combinations of central memory T cells with CD4+ T cells that are genetically modified to express a chimeric receptor. In embodiments the genetically modified host cell comprises a nucleic acid comprising a polynucleotide coding for a ligand binding domain, a polynucleotide comprising a customized spacer region, a polynucleotide comprising a transmembrane domain, and a polynucleotide comprising an intracellular signaling domain. It has been surprisingly found that the length of the spacer region can affects the ability of chimeric receptor modified T cells to recognize target cells in vitro and affects in vivo efficacy of the chimeric receptor modified T cells. Pharmaceutical formulations produced by the method, and methods of using the same, are also described.