CAR T Cell Phosphorylation Site Mutations for Toxicity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current chimeric antigen receptor (CAR) T cell therapies for cancer face challenges with poor persistence and excessive activation leading to relapses and toxicities, despite improved efficacy with co-stimulatory domains, indicating a need to modulate CAR expression and activity.
Innovation Solution
Development of CAR polypeptides with mutated CD28 cytoplasmic domains, specifically altering phosphorylation sites such as Y206 and Y218, to attenuate or enhance CAR activity and expression, combined with phosphomimetic or non-phosphorylatable amino acid substitutions, to optimize T cell function and reduce adverse effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If co-stimulatory domains (CD28) are added to CARs to improve tumor killing efficacy, then anti-tumor activity is enhanced, but excessive T cell activation occurs leading to toxicities
Solution Approach 1:
The patent applies parameter changes by mutating specific phosphorylation sites (Y206 and/or Y218) in the CD28 cytoplasmic domain of the CAR. These mutations alter the biochemical parameters of the co-stimulatory domain, modifying how it transmits activation signals to the T cell. This allows tuning the activation threshold and signal strength to achieve effective anti-tumor activity while reducing excessive activation and associated toxicities.
Solution Approach 2:
The patent applies local quality by making specific localized modifications to the CD28 domain rather than altering the entire CAR structure. The mutations are confined to specific phosphorylation sites (Y206 and/or Y218) within the cytoplasmic tail of CD28, leaving other functional regions intact. This localized modification approach preserves essential co-stimulatory functions while selectively modulating activation signaling to reduce toxicities.
2Reliability
If co-stimulatory domains (CD28) are added to CARs to improve tumor killing efficacy, then tumor killing is enhanced, but T cell persistence is reduced
Solution Approach 1:
The patent uses parameter changes by mutating phosphorylation sites in the CD28 domain to alter the temporal dynamics of T cell activation. The mutations modify signal duration and intensity, creating a more sustained but controlled activation pattern that promotes T cell persistence in the tumor microenvironment while maintaining effective tumor killing capability.
Solution Approach 2:
The patent applies dynamics by creating CARs with mutated CD28 domains that exhibit dynamic signal transmission properties. The phosphorylation site mutations allow the co-stimulatory domain to adapt its signaling behavior, providing sustained activation during tumor encounter while preventing excessive activation that would lead to T cell exhaustion or death, thereby improving persistence.
3Object-affected harmful factors
If phosphorylation sites (Y206, Y218) in CD28 are mutated to attenuate CAR activity, then toxicities are reduced, but CAR expression and activity decrease
Solution Approach 1:
The patent applies parameter changes by selectively mutating specific phosphorylation sites (Y206 and/or Y218) rather than eliminating co-stimulatory signaling entirely. This partial modification approach adjusts the activation threshold and signal strength parameters, reducing toxicities associated with excessive activation while preserving sufficient CAR activity for effective tumor targeting and killing.
Solution Approach 2:
The patent applies partial action by mutating only specific phosphorylation sites within the CD28 domain rather than disabling the entire co-stimulatory function. This partial modification strategy reduces harmful over-activation while maintaining enough co-stimulatory signaling to support effective CAR T cell function, achieving a balance between reducing toxicity and preserving activity.
Data Source
AI summary
Disclosed herein are chimeric antigen receptor (CAR) polypeptides, which can be used with adoptive cell transfer to target and kill cancers, that comprise a costimulatory signaling region having a mutated form of a cytoplasmic domain of CD28 with altered phosphorylation at Y206 and/or Y218. Also disclosed are immune effector cells, such as T cells or Natural Killer (NK) cells, that are engineered to express these CARs. Therefore, also disclosed are methods of providing an antitumor immunity in a subject with a tumor associated antigen-expressing cancer that involves adoptive transfer of the disclosed immune effector cells engineered to express the disclosed CARs.