Conditionally Active CARs for Selective Tumor Targeting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods struggle to engineer proteins that are inactive at normal physiological conditions but active at aberrant conditions, while maintaining activity equivalent to or better than wild-type proteins at aberrant conditions.
Innovation Solution
The development of conditionally active chimeric antigen receptors (CARs) that are reversibly or irreversibly inactivated at normal physiological conditions but active at aberrant conditions. These CARs comprise an antigen-specific targeting region evolved from a parent protein, a transmembrane domain, and an intracellular signaling domain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If destabilizing mutations are introduced to inactivate protein at normal physiological conditions, then the protein becomes inactive at normal conditions, but the protein's activity is reduced greater than expected at aberrant conditions
Solution Approach 1:
The patent applies parameter changes by introducing destabilizing mutations that alter the protein's stability parameters, causing it to be inactive at normal physiological conditions (pH 7.4, 37°C) while maintaining or enhancing activity at aberrant conditions (acidic pH in tumors). This resolves the contradiction by changing the operational parameters of the protein to achieve conditional selectivity.
Solution Approach 2:
The patent implements dynamics by creating a protein that dynamically changes its conformational state based on environmental conditions. The engineered protein transitions from an inactive state at normal physiological conditions to an active state at acidic pH, allowing it to adapt its activity level to the local environment, thus achieving both selectivity and maintained productivity at target sites.
2Reliability
If activity increasing mutations are combined with destabilizing mutations, then the protein can be conditionally active, but the protein structure becomes less stable
Solution Approach 1:
The patent applies local quality by introducing destabilizing mutations at specific locations in the protein structure that do not compromise the overall fold or essential functional domains. The mutations are strategically placed to affect stability without destroying the protein's core structure, allowing conditional activity while maintaining sufficient structural integrity for function at target sites.
Solution Approach 2:
The patent creates a composite molecular structure by combining destabilizing mutations with activity-enhancing mutations in a way that produces a new functional entity with properties different from the parent protein. The engineered CAR comprises multiple domains (antigen-binding domain, transmembrane domain, signaling domain) where destabilizing elements are balanced by stabilizing structural frameworks, achieving conditional activation while maintaining necessary stability.
3Reliability
If the CAR is designed to be inactive at normal physiological conditions, then selectivity for disease sites is improved, but therapeutic efficacy may be reduced
Solution Approach 1:
The patent applies preliminary action by pre-engineering the CAR with destabilizing mutations that ensure it remains inactive during circulation and transport to the tumor site. The protein is prepared in an inactive state that protects it from off-target effects, and then activates at the disease site when exposed to acidic pH, ensuring both selectivity and therapeutic efficacy are achieved through conditional activation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This disclosure relates to a chimeric antigen receptor for binding with a target antigen. The chimeric antigen receptor comprises at least one antigen specific targeting region evolved from a wild-type protein or a domain thereof and having at least one of: (a) a decrease in activity in the assay at the normal physiological condition compared to the antigen specific targeting region of the wild-type protein or a domain thereof, and (b) an increase in activity in the assay under the aberrant condition compared to the antigen specific targeting region of the wild-type protein or a domain thereof. A method for generating the chimeric antigen receptor and cytotoxic cells that express the chimeric antigen receptor are also provided.