RNA Destabilizing Elements for CAR T-Cell Toxicity Control
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Solution Overview
Problem
Current CAR T-cell therapies for cancer treatment face challenges with toxicity due to the persistence of non-responsive CAR T-cell clones and the difficulty in controlling acute toxicity, as existing regulatory approaches such as kill switches and transient CAR expression methods fail to adequately safeguard against toxicity and maintain long-term surveillance benefits.
Innovation Solution
The use of RNA Destabilizing Elements (RDEs) to control the expression of transgenes in eukaryotic cells, such as T-cells, allowing for regulated and responsive CAR activity through metabolic and redox state-dependent mechanisms, enabling precise timing and duration of CAR expression and payload delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If kill switch technology is used to control CAR T-cells, then safety against toxicity is improved, but reliability of toxicity control is worsened because non-responsive clones continue to proliferate and kill target cells
Solution Approach 1:
The patent segments the control mechanism by introducing multiple independent regulatory elements (RDEs) that can be distributed across different transgene copies. This segmentation ensures that if some clones are non-responsive, others remain controllable, thereby maintaining overall reliability of the kill switch function while managing toxicity.
Solution Approach 2:
The patent changes the parameter of transgene copy number distribution and RDE placement strategy to optimize control reliability. By adjusting these parameters, the system ensures adequate representation of controllable clones even in the presence of selection pressure, resolving the contradiction between safety and reliability.
2Object-affected harmful factors
If transient CAR expression is used, then acute toxicity control is improved, but loss of long-term surveillance benefit occurs
Solution Approach 1:
The patent implements dynamic control of CAR expression through RDEs that can be modulated over time. This allows the system to transition from high expression (for efficacy) to low or zero expression (for toxicity control), while maintaining the ability to reactivate surveillance if needed, thus resolving the contradiction between acute toxicity control and long-term surveillance.
Solution Approach 2:
The patent enables periodic reactivation of CAR expression through controlled degradation and re-synthesis cycles. This periodic action allows temporary suppression of CAR to reduce acute toxicity, followed by reactivation to restore surveillance function, effectively managing both acute toxicity and long-term surveillance needs.
3Reliability
If multiple transgenes are introduced to overcome selection pressure, then reliability of control is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by using identical or similar RDE sequences across multiple transgene copies. This multi-functional approach allows a single control mechanism design to regulate multiple transgenes simultaneously, improving control reliability without proportionally increasing complexity, as the same regulatory logic applies to each copy.
Solution Approach 2:
The patent uses copying of the RDE control element across multiple transgene copies rather than creating entirely independent control systems. This copying strategy maintains reliability through redundancy while minimizing the increase in complexity, as the regulatory mechanism is replicated rather than reinvented for each transgene.
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
This approach provides a more controlled and targeted CAR activity, reducing toxicity and maintaining therapeutic efficacy by ensuring CAR expression is activated only when needed, thereby enhancing the safety and effectiveness of CAR T-cell therapies.
Implementation Method 1
The RDEs can be bound by polypeptides including, for example, ARE poly(U) binding/degradation factor (AUF-1), tristetraprolin (TTP), human antigen-related protein (HuR)
Implementation Method 2
allowing for regulated and responsive CAR activity through metabolic and redox state-dependent mechanisms
Implementation Method 3
allowing for regulated and responsive CAR activity through metabolic and redox state-dependent mechanisms
Data Source
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AI summary
The present invention relates to a method of controlling a transgene, comprising the steps of obtaining a primary T-cell comprising a chimeric antigen receptor, and a heterologous nucleic acid comprising a polynucleotide encoding the transgene that is operably linked to a polynucleotide encoding a RNA degradation element (RDE), wherein the RDE is an AU rich element, wherein the heterologous nucleic acid is transcribed to make a transcript encoding the transgene operably linked to the RDE; exposing the primary T-cell to a ligand for the chimeric antigen receptor wherein binding of the ligand by the chimeric antigen receptor activates the primary T-cell and thereby changes a metabolic state of the primary T-cell; and expressing the transgene wherein the amount of polypeptide made from the transgene is increased after the change in metabolic state of the primary T-cell.