Related Experiment Video
Updated: Dec 18, 2025
A Syngeneic Mouse B-Cell Lymphoma Model for Pre-Clinical Evaluation of CD19 CAR T Cells
Published on: October 16, 2018
A rational mouse model to detect on-target, off-tumor CAR T cell toxicity
Mauro Castellarin1,2, Caroline Sands1, Tong Da1
1Center for Cellular Immunotherapies, Abramson Cancer Center, and.
Abstract:
Off-tumor targeting of human antigens is difficult to predict in preclinical animal studies and can lead to serious adverse effects in patients. To address this, we developed a mouse model with stable and tunable human Her2 (hHer2) expression on normal hepatic tissue and compared toxicity between affinity-tuned Her2 chimeric antigen receptor T cells (CARTs). In mice with hHer2-high livers, both the high-affinity (HA) and low-affinity (LA) CARTs caused lethal liver damage due to immunotoxicity. In mice with hHer2-low livers, LA-CARTs exhibited less liver damage and lower systemic levels of IFN-γ than HA-CARTs. We then compared affinity-tuned CARTs for their ability to control a hHer2-positive tumor xenograft in our model. Surprisingly, the LA-CARTs outperformed the HA-CARTs with superior antitumor efficacy in vivo. We hypothesized that this was due, in part, to T cell trafficking differences between LA and HA-CARTs and found that the LA-CARTs migrated out of the liver and infiltrated the tumor sooner than the HA-CARTs. These findings highlight the importance of T cell targeting in reducing toxicity of normal tissue and also in preventing off-tumor sequestration of CARTs, which reduces their therapeutic potency. Our model may be useful to evaluate various CARTs that have conditional expression of more than 1 single-chain variable fragment (scFv).
Insights
Low-affinity chimeric antigen receptor T cells (CARTs) reduced liver toxicity and improved anti-tumor efficacy by enhancing T cell trafficking. This CART therapy optimization is crucial for reducing off-tumor targeting and improving patient outcomes.
Area of Science:
- Immunology
- Oncology
- Preclinical models
Background:
- Off-tumor targeting of human antigens by chimeric antigen receptor T cells (CARTs) is challenging to predict in preclinical models, potentially causing severe adverse effects.
- Developing predictive models is essential for assessing CART safety and efficacy, especially concerning human antigen expression on normal tissues.
Purpose of the Study:
- To develop a mouse model with tunable human Her2 (hHer2) expression in normal liver tissue.
- To compare the toxicity and efficacy of affinity-tuned Her2 CARTs in a preclinical setting.
Main Methods:
- Created a mouse model with stable, tunable hHer2 expression on hepatic tissue.
- Administered high-affinity (HA) and low-affinity (LA) Her2 CARTs to mice with varying hHer2 liver expression levels.
- Assessed liver toxicity, systemic cytokine levels (IFN-γ), and anti-tumor efficacy against hHer2-positive xenografts.
- Investigated T cell trafficking patterns between liver and tumor sites.
Main Results:
- Both HA- and LA-CARTs caused lethal liver toxicity in mice with high hHer2 liver expression.
- In mice with low hHer2 liver expression, LA-CARTs showed reduced liver damage and lower IFN-γ levels compared to HA-CARTs.
- LA-CARTs demonstrated superior anti-tumor efficacy against hHer2-positive xenografts.
- LA-CARTs exhibited enhanced migration from the liver to the tumor site compared to HA-CARTs.
Conclusions:
- T cell targeting affinity is critical for mitigating off-tumor toxicity in normal tissues.
- Optimizing CART affinity can prevent off-tumor sequestration, thereby enhancing therapeutic potency.
- The developed mouse model serves as a valuable tool for evaluating CARTs with conditional antigen expression, including those targeting multiple single-chain variable fragments (scFvs).
More Related Videos
06:08Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-Derived Xenograft Mouse Model
Published on: February 10, 2023
08:46A Real-time Potency Assay for Chimeric Antigen Receptor T Cells Targeting Solid and Hematological Cancer Cells
Published on: November 12, 2019
