Chimeric Antigen Receptor T-Cell Recruitment and Killing can be Evaluated on an Organ-Chip model system

Abstract Objective. Chimeric antigen (CAR) T-cell therapies for solid tumors are challenging to develop due to the lack of human relevant models that adequately capture the mechanisms of CAR T-cell recruitment-a critical yet often overlooked rate-limiting step. The current study aimed to develop a novel system for investigating both the recruitment and killing capacity of CAR T cells in Organ-Chips. Methods. Chip-S1™ Stretchable Chips (Emulate) were seeded with a human HER2+ non-small cell lung cancer cell line (NSCLC) in the top channel and lung microvascular endothelial cells in the vascular (bottom) channel to create a tumor-vascular interface. Both channels were primed with an NSCLC-specific mix of chemokines and cytokines. HER2-specific CAR T cells were perfused through the vascular channel. Total CAR T-cell recruitment into the top channel and CAR T-mediated killing were measured over 48 hours. The IL-2 cytokine was also co-administered with CAR T cells as immunotherapy. Results. HER2 CAR T cells demonstrated significant antigen-specific killing when recruited to the top channel as measured by caspase activity and cytokine release compared to the control. Furthermore, IL-2 co-therapy increased CAR T-cell recruitment and antigen-specific killing compared to the control group. Conclusion. These findings suggest that human-centric Organ-Chips can evaluate CAR T-cell therapies for solid tumors by integrating the critical rate-limiting steps of CAR T recruitment and killing.