# Synthetic biology toolkit for precise tuning of T cell activity

> **NIH NIH R21** · TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR · 2024 · $189,781

## Abstract

Project Summary / Abstract. Chimeric antigen receptor (CAR) T cell-based immunotherapy has
shown curative potential in patients with haematological malignancies. However, it faces significant safety issues
(e.g., cytokine release syndrome and neurotoxicity) and efficacy loss arising from tonic signaling and T cell
exhaustion. These undesireable features are more or less decoded in the distal end of lymphocyte activation
pathway, the two-component Calcium Release-Activated Calcium (CRAC) channel composed of stromal
interaction molecule (STIM) and ORAI to form a major Ca2+ entry route in T cells and control T cell activation.
Upon T-cell receptor (TCR) engagement, Ca2+ depletion in the endoplasmic reticulum (ER) is sensed by stromal
interaction molecule 1 (STIM1) to initiate a series of conformational changes, culminating in the activation of the
pore-forming subunit of the CRAC channel, ORAI1. Ca2+ influx induces a series of processes in T cells, including
the secretion of cytolytic granules and the activation of Ca2+-dependent enzymes, including calcineurin, CaMKII
and Erk1/2, as well as master transcription factors, such as NF-κB and nuclear factor of activated-T cells (NFAT),
that are essential for adaptive immunity. Most importantly, nuclear translocated NFAT differentially engages its
binding partners to promote the activation, differentiation, anergy/exhaustion, and effector functions of various T
cell subsets. Notably, tonic signaling and exhaustion observed in CAR-T cell therapy are associated with
hyperactive Ca2+/NFAT signaling. Till now, no FDA-approved CRAC channel blockers are in hand to modulate
the CRAC channel for therapeutic applications. There remains, therefore, a critical need to exploit novel
interventional approaches by targeting the distal CRAC channels in T cells. Unlike most existing studies centered
on CAR per se or the proximal signaling components in modulating CAR-T cell activation pathway, this project
focuses on engineering the distal end of lymphocyte activation pathway without any modifications to the chimeric
antigen receptor or proximal TCR signaling. The m-PIs propose to to develop a suite of genetically-encoded
CRAC channel Blockers (CRAB) that can be precisely controlled by light or drugs (LiCRAB for Aim 1, and
DiCRAB for Aim 2, respectively), thereby conferring tight control of T cell activity to fine-tune T cell efficacy and
mitigate CAR-T cell tonic signaling and/or exhaustion. The successful execution of this project will explore
innovative immunoengineering approaches to accelerate the design of intelligent cell-based therapies for human
disease. Mechanistically, the tools can be utilized to probe the kinetic requirement of Ca2+/NFAT signaling during
CAR-T cell activation. From a translational perspective, we will generate broadly-applicable genetically-encoded
tools for therapeutic T cell functional tuning, which hold great promise to overcome tonic signaling / exhaustion,
and curtail cytokine storm asso...

## Key facts

- **NIH application ID:** 10885170
- **Project number:** 5R21AI174606-02
- **Recipient organization:** TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
- **Principal Investigator:** Yubin Zhou
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $189,781
- **Award type:** 5
- **Project period:** 2023-07-10 → 2025-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10885170

## Citation

> US National Institutes of Health, RePORTER application 10885170, Synthetic biology toolkit for precise tuning of T cell activity (5R21AI174606-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10885170. Licensed CC0.

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