NR4A1 Genetic Circuits for Activation-Controlled CAR-T Expression
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Solution Overview
Problem
Existing CAR-T cell therapies face challenges in modulating therapeutic gene expression to prevent side effects and achieve optimal anti-tumor responses, with high CAR expression leading to T cell exhaustion and inappropriate antigen recognition.
Innovation Solution
Genetic circuits with transcriptional regulatory regions from the NR4A1 locus that selectively switch on customizable genetic programs in response to CAR receptor or TCR ligation, allowing precise control of gene expression and delivery of bioactive molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high expression of CAR is achieved, then anti-tumor response is enhanced, but T cell exhaustion and inappropriate antigen recognition occur
Solution Approach 1:
The patent implements dynamic control of CAR expression through inducible promoters that respond to T cell activation signals. The promoter includes response elements that are activated only when the CAR engages its target antigen, allowing the system to transition from low baseline expression to high activated expression only when needed, thereby preventing T cell exhaustion while maintaining anti-tumor response capability.
Solution Approach 2:
The patent modifies the transcriptional regulatory parameters by incorporating specific response elements from the NR4A1 locus that change the expression dynamics. The promoter's activity is modulated based on T cell activation state, transforming static high expression into dynamic conditional expression that adapts to cellular conditions and prevents harmful effects of constitutive high expression.
2Productivity
If CAR-T cell activity is increased, then therapeutic efficacy is improved, but side effects and toxicity increase
Solution Approach 1:
The patent incorporates feedback mechanisms through T cell activation-responsive promoters that sense the functional state of the CAR-T cell. When the CAR engages target antigen and activates the T cell, the promoter responds by increasing transgene expression. This feedback loop ensures that therapeutic genes are expressed at high levels only when the T cell is actively engaged with tumor antigen, preventing off-target effects and toxicity while maintaining therapeutic efficacy.
Solution Approach 2:
The system transitions from static high expression to dynamic conditional expression where the promoter activity is regulated by T cell activation status. This dynamic regulation allows the system to achieve high therapeutic output only when needed (upon antigen engagement) while maintaining low baseline expression that prevents unnecessary side effects and toxicity.
3Speed
If constitutive high expression of CAR is used, then immediate anti-tumor activity is achieved, but T cell memory formation is compromised
Solution Approach 1:
The patent employs dynamic promoter regulation that prevents constitutive high expression while enabling rapid response upon activation. The inducible promoter maintains low baseline expression that preserves T cell quiescence and memory potential, while simultaneously providing rapid high expression capability when the CAR engages target antigen, thus achieving both immediate anti-tumor activity and preserved memory formation.
Data Source
AI summary
The present disclosure generally relates to genetic circuits including response elements engineered from the NR4A1 that augment chimeric antigen receptor activation with the delivery of a bioactive molecule. Particularly, the disclosure provides nucleic acid constructs including response elements operably linked to a nucleic acid sequence of interest such that are responsive to activation of CAR-T cells. The disclosure also relates to vectors and cells including the genetic circuits and the nucleic acid constructs. Also provided are methods of inducing an immune response, methods of treatment of subjects, and methods for delivering a bioactive molecule by an activated T cell having a chimeric antigen receptor and the response element constructs of the disclosure.