GD3 CAR T-Cell Efficacy via 4-1BB Co-Stimulation
Solution Overview
Problem
Current anti-GD3 chimeric antigen receptors (CARs) require systemic infusion of high doses of interleukin 2 (IL2) to achieve 50% efficacy in eradicating GD3-positive tumors, indicating a need for improved efficacy and reduced treatment burden.
Innovation Solution
Development of new GD3-specific CAR constructs with different scFV derived from GD3-specific antibodies, incorporating a signal peptide, an extracellular ligand binding-domain, a CD8α hinge, a CD8α transmembrane domain, and a cytoplasmic domain including a CD3 zeta signaling domain and a co-stimulatory domain from 4-1BB, to enhance specificity and activity of T-cells against GD3-positive cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current anti-GD3 chimeric antigen receptors (CARs) are used, then T-cells can be redirected against GD3-positive tumor cells, but high doses of interleukin 2 (IL2) are required to achieve 50% efficacy in eradicating tumors
Solution Approach 1:
The patent modifies the signaling domains within the CAR structure, specifically using alternative co-stimulatory domains (such as CD28, 4-1BB, or OX40) and transmembrane domains (such as CD8alpha or IgG1) to change the functional parameters of the CAR. These parameter changes enable the CAR to achieve enhanced T-cell activation and proliferation with reduced dependency on high doses of IL2, thereby improving tumor eradiction efficacy while reducing the quantity of cytokine required
Solution Approach 2:
The patent constructs composite CAR molecules by combining different functional domains from various immune receptors. The composite structure includes an extracellular antigen-binding domain (scFv against GD3), a transmembrane domain, one or more co-stimulatory domains, and a signaling domain. This composite design integrates multiple signaling pathways within a single CAR molecule, enabling synergistic activation of T-cells that reduces the need for high doses of IL2 while maintaining or enhancing anti-tumor efficacy
2Productivity
If first generation CARs with CD3zeta or Fc receptor gamma signaling domains are used, then T-cell cytotoxicity can be redirected, but prolonged expansion and anti-tumor activity in vivo are not achieved
Solution Approach 1:
The patent merges multiple functional domains into a single CAR construct, combining the antigen-binding scFv domain with co-stimulatory domains (such as CD28, 4-1BB, or OX40) and signaling domains (such as CD3zeta). This merging creates a multi-functional receptor that simultaneously provides antigen recognition, co-stimulation, and signaling capabilities, enabling prolonged T-cell expansion and sustained anti-tumor activity in vivo that first-generation CARs could not achieve
Solution Approach 2:
The patent designs universal CAR constructs that can be applied to target various tumor antigens by simply changing the extracellular antigen-binding domain while maintaining the same multi-functional intracellular signaling architecture. The universal co-stimulatory and signaling domains provide prolonged expansion and sustained activity across different CAR applications, making the design broadly applicable while solving the duration limitation of first-generation CARs
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
The engineered T-cells expressing these new CARs display reactivity against GD3-positive cells, contributing to antigen-dependent activation and proliferation, thereby offering a significant clinical advantage for treating both solid and liquid tumors.
Implementation Method 1
an extracellular ligand binding-domain comprising VH and VL from a monoclonal anti-GD3 antibody
Implementation Method 2
a cytoplasmic domain including a CD3 zeta signaling domain
Implementation Method 3
a co-stimulatory domain from 4-1BB
Data Source
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AI summary
The present invention relates to Chimeric Antigen Receptors (CAR) that are recombinant chimeric proteins able to redirect immune cell specificity and reactivity toward selected membrane antigens, and more particularly in which extracellular ligand binding is a scFV derived from a GD3 monoclonal antibody, conferring specific immunity against GD3 positive cells. The engineered immune cells endowed with such CARs are particularly suited for treating solid tumors such as melanomas, carcinomas or liquid tumor such as T-cell lymphoblastic leukemia.