CD28H Domain CARs for NK Cell Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current immunotherapy with CAR-T cells faces challenges such as severe cytokine-release syndrome and neurotoxicity, and the need for genetically silencing TCRs in allogeneic CAR-T cells to prevent graft-versus-host disease, which complicates the production and safety of CAR-T cell therapy.
Innovation Solution
Development of chimeric antigen receptors (CARs) that include a CD28H activation domain to overcome inhibitory signaling by receptors like CD94-NKG2A and KIR2DL1, enhancing NK cell activation and tumor targeting without the need for TCR silencing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CAR-T cell therapy is used to treat cancer, then anti-tumor efficacy is improved, but severe cytokine-release syndrome and neurotoxicity occur
Solution Approach 1:
The patent changes the signaling parameters by replacing the traditional CD3ζ signaling domain with CD28H signaling domain in the CAR construct. This parameter change modifies the activation threshold and signaling intensity, enabling effective anti-tumor activity while reducing the severity of cytokine-release syndrome and neurotoxicity side effects.
Solution Approach 2:
The patent creates a composite CAR structure by combining the antigen-binding domain (scFv), transmembrane domain, and a novel intracellular signaling domain composed of CD28H fused with CD3ζ. This composite structure integrates the advantages of co-stimulation (CD28H) with antigen recognition (CD3ζ), achieving balanced activation and reduced toxicity.
2Ease of manufacture
If allogeneic CAR-T cells are used to reduce cost and simplify production, then manufacturing complexity is reduced, but TCR silencing is required to prevent graft-versus-host disease
Solution Approach 1:
The patent extracts and eliminates the need for TCR silencing by using NK cells instead of T cells as the carrier for CAR expression. Since NK cells lack TCR, the harmful GVHD effect is removed while maintaining the benefits of allogeneic cell therapy.
Solution Approach 2:
The patent uses donor-derived NK cells that can be cryopreserved and expanded ex vivo, creating a copyable, off-the-shelf product. These allogeneic NK cells express the CAR and can be stored and administered without requiring autologous cell collection and processing, greatly simplifying manufacturing.
3Reliability
If inhibitory receptor signaling is maintained in NK cells, then NK cell safety and regulation are preserved, but anti-tumor cytotoxicity is reduced
Solution Approach 1:
The patent changes the signaling parameters by introducing CD28H signaling domain which has different activation thresholds and signaling characteristics compared to traditional CAR signaling. This allows the CAR to overcome inhibitory receptor signals (like KIR and NKG2A) while maintaining safety through regulated activation.
Solution Approach 2:
The patent applies preliminary anti-action by designing the CAR with CD28H domain that proactively counteracts inhibitory signals before they can suppress NK cell function. The CD28H signaling provides a dominant activating signal that overrides the negative regulation from inhibitory receptors, ensuring effective tumor killing while maintaining controlled activation.
Data Source
AI summary
Chimeric antigen receptors including (a) an antigen binding domain; (b) a transmembrane domain; and (c) an intracellular domain comprising a first intracellular signaling domain from CD28 homolog (CD28H) and a second intracellular signaling domain are provided. In some examples, the second intracellular domain is from 2B4, TCRζ, FcεR1γ, or DAP12. Chimeric antigen receptors including (a) an antigen binding domain; (b) a transmembrane domain; and (c) an intracellular domain comprising a first intracellular signaling domain from CD28H, a second intracellular signaling domain from 2B4, and a third intracellular signaling domain are also provided. In some examples, the third intracellular domain is from TCRζ, FcεR1γ, or DAP12. Nucleic acid molecules encoding the CARs and expression vectors including the nucleic acids are also provided. Isolated cells (such as T cells or natural killer cells) expressing the CARs and methods of treating a subject with cancer with the isolated cells are provided.