Mu3A4-CAR T Cell Targeting CD45RA Isoform
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Solution Overview
Problem
Current CAR-T cell therapies for acute myeloid leukemia (AML) face challenges due to the broad reactivity of CD45 antibodies with hematopoietic tissues, leading to severe side effects and limited therapeutic efficacy.
Innovation Solution
Development of a non-natural murine chimeric antigen receptor (CAR) specific for human CD45RA, known as Mu3A4-CAR, which is designed to target CD45RA-expressing leukemia cells without affecting normal hematopoietic stem cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CD45 antibodies are used for targeted therapy, then tumor cells can be recognized and killed, but severe side effects occur due to broad reactivity with normal hematopoietic tissues
Solution Approach 1:
The patent segments the CD45 antigen into a specific isoform (CD45RA) and targets only that segment rather than the entire CD45 molecule. This is achieved by designing CAR-T cells with scFv regions specific for CD45RA, allowing differentiated targeting of leukemia cells expressing this isoform while sparing normal hematopoietic cells that express different CD45 isoforms, thus reducing off-target toxicity.
Solution Approach 2:
The patent applies local quality by creating CAR-T cells with specific recognition domains (scFv) that are locally optimized to bind CD45RA with high affinity. The CAR structure includes specific components (scFv, hinge, transmembrane, intracellular domains) that are locally tailored to achieve selective binding to CD45RA-positive leukemia cells while maintaining compatibility with normal tissues.
2Reliability
If conventional CAR-T cells are used for AML treatment, then some therapeutic effect is achieved, but therapeutic efficacy is limited and relapse occurs
Solution Approach 1:
The patent changes the targeting parameter from broad CD45 to specific CD45RA isoform, and uses engineered scFv regions with optimized binding characteristics. The CAR-T cells are designed with specific intracellular signaling domains (4-1BB and CD3ζ) that enhance activation strength. This parameter optimization enables more effective and durable remission by improving the quality of tumor cell recognition and killing.
3Measurement precision
If CD45RA-specific CAR-T cells are designed, then specificity to leukemia cells is improved, but development complexity increases
Solution Approach 1:
The patent achieves universality by creating a modular CAR gene structure that can be applied to different leukemia subtypes expressing CD45RA. The standardized CAR design with interchangeable scFv regions allows the same basic CAR architecture to target different CD45RA-positive malignancies, reducing the need for entirely new CAR designs for each application while maintaining high specificity.
Data Source
AI summary
The present disclosure provides a preparation method of a non-natural anti-human CD45RA murine chimeric antigen receptor (CAR). In the present disclosure, eukaryotic expression vectors pcDNA3.1/Mu3A4-4-1BB-3ζ and pcDNA3.1/Mu3A4-4-1BB-3ζ-EGFP and a lentiviral expression vector pLenti/Mu3A4-4-1BB-3ζ are constructed based on molecular biology using a mouse-derived 3A4 antibody. The lentiviral expression vector pLenti/Mu3A4-4-1BB-3ζ can successfully infect human T cells and effectively kill 3A4-positive target cells such as KG1a cells and Raji cells. The recognition of antigens by Mu3A4CAR does not depend on antigen presentation process and is not restricted by a major histocompatibility complex (MHC), thus overcoming tumor immune evasion to kill 3A4-positive tumor cells more effectively.