Visualizing CAR-T cell Immunotherapy Using 3 Tesla Fluorine-19 MRI.

Area of Science:

• Oncology
• Immunotherapy
• Biomedical Imaging

Background:

• Chimeric antigen receptor (CAR) T cell therapy shows promise for hematological malignancies but faces challenges with patient response, side effects, and solid tumor treatment.
• An effective imaging tool is needed to track CAR T-cell location, predict treatment success, and identify off-target toxicities.

Purpose of the Study:

• To visualize perfluorocarbon (PFC)-labeled CAR T-cells in a mouse leukemia model using 3 Tesla ¹⁹F MRI.
• To compare the in vivo cytotoxicity of PFC-labeled CAR T-cells versus unlabeled CAR T-cells.

Main Methods:

• NSG mice with established leukemia received intratumoral injections of PFC-labeled CAR T-cells, unlabeled CAR T-cells, PFC-labeled untransduced T-cells, or saline.
• ¹⁹F MRI was used to detect PFC-labeled CAR T-cells at multiple time points post-injection.
• Bioluminescence imaging (BLI) monitored tumor progression in all groups.

Main Results:

• ¹⁹F MRI successfully detected PFC-labeled CAR T-cells in tumors up to 7 days post-injection.
• Both PFC-labeled and unlabeled CAR T-cells significantly reduced tumor burden compared to controls (p < 0.05).
• No significant difference in cytotoxicity was observed between PFC-labeled and unlabeled CAR T-cells.

Conclusions:

• Clinical field strength ¹⁹F MRI can effectively visualize PFC-labeled CAR T-cells in vivo for up to 7 days.
• PFC labeling does not compromise the in vivo efficacy of CAR T-cells.
• This imaging approach holds potential for tracking CAR T-cell therapies in preclinical studies and future clinical applications, particularly for localized CAR T-cell injections.