# CAR NKT Cell Immunotherapy of Neuroblastoma

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 2022 · $359,801

## Abstract

Abstract
Despite remarkable progress in treating B cell malignancies, T cells expressing chimeric antigen receptors
(CARs) remain largely ineffective in solid tumors. We demonstrated that unlike conventional T and CAR-T cells,
V24-invariant natural killer T cells (NKTs) and CAR-NKTs effectively traffic to tumor sites in xenogeneic models
of neuroblastoma (NB), which led to initiation of a first-in-human phase 1 clinical trial evaluating autologous GD2-
specific CAR-NKTs in children with NB. Interim results from this trial have shown that the treatment is well-
tolerated and produces antitumor activity, underscoring the need for systematic investigation of NKTs as an
alternative cellular platform for CAR-redirected immunotherapy. We reported that repeated antigenic stimulation
of NKTs and CAR-NKTs leads to their effector-like differentiation, exhaustion, and loss of antitumor activity. Our
preliminary data demonstrate that Wnt signaling—specifically, activation of transcription factor LEF1—is required
and sufficient for maintenance of the CD62L+ central memory-like NKT subset and is associated with NKT
metabolic and functional fitness. These findings provide rationale for examining the role and potential therapeutic
targeting of LEF1 in CAR-NKTs for cancer immunotherapy. Pre-clinical in vivo studies of CAR-NKTs have been
limited to xenogeneic models, which do not allow for evaluation of the full spectrum of downstream innate and
adaptive immune responses. To address this gap, we have developed protocols to generate and expand highly
pure murine NKTs that express a murine CAR targeting the GD2 antigen expressed on human and murine NB
cells. We have also adapted a syngeneic NB model that faithfully recapitulates the clinical and pathological
characteristics of high-risk NB in children. We hypothesize that 1) LEF1 transcriptional activity is required for
and can be therapeutically enhanced to maintain CAR-NKT cell metabolic fitness, in vivo persistence, and
durable antitumor activity; and 2) CAR-NKT antitumor activity depends on direct targeting of tumor cells, control
of tumor-associated macrophages, transactivation of NK cells and induction of tumor-specific T cells. These
hypotheses will be tested in the following specific aims: 1) to examine and therapeutically explore the
mechanism responsible for maintenance of human central memory-like NKT and CAR-NKT cells, and 2) to
explore the mechanism by which CAR-NKTs mediate antitumor activity in a syngeneic NB model. We will use
genetic loss-of-function and gain-of-function approaches to study the role of LEF1 in CAR-NKT functional
differentiation, metabolism, and antitumor activity using in vitro experimental systems with human cells and in
vivo xenogeneic NB models in mice. To study the mechanism by which CAR-NKTs mediate antitumor activity in
the syngeneic setting, we will perform a side-by-side comparison of murine NKTs and T cells expressing a GD2-
specifc CAR. The proposed experiments will mecha...

## Key facts

- **NIH application ID:** 10427430
- **Project number:** 5R01CA262250-02
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Leonid S Metelitsa
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $359,801
- **Award type:** 5
- **Project period:** 2021-06-12 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10427430

## Citation

> US National Institutes of Health, RePORTER application 10427430, CAR NKT Cell Immunotherapy of Neuroblastoma (5R01CA262250-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10427430. Licensed CC0.

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