Tu173 - Advancing CAR T Clinical Development with High-Parameter CyTOF Technology

Abstract Text: Adoptive immunotherapy using chimeric antigen receptor (CAR) T cells is a revolutionary treatment in cancer therapy that has achieved great success in hematological B cell malignancies; however, it has faced significant challenges in solid tumors. A better understanding of CAR T biology will accelerate development of CAR T therapies with improved durability, antitumor efficacy and decreased toxicities.
High-parameter cytometry is a powerful tool to functionally characterize CAR T cells at multiple stages of clinical development. CyTOF™ technology, or mass cytometry, overcomes the limitations that reduce the sensitivity of fluorescence-based cytometry, such as autofluorescence and signal overlap, and enables users to streamline workflows and minimize technical variations. Here, we present a 40-plus-marker CyTOF panel to simultaneously analyze protein expression of phenotypic and functional markers in single CAR T cells.
CD19-targeted CAR T cells were expanded in vitro and co-cultured with Nalm6 cells for 2–5 days. Samples co-cultured at different time points were stained with a CyTOF panel including 40-plus surface, cytoplasmic and nuclear markers, barcoded, frozen and simultaneously acquired on a CyTOF XT system. Comprehensive profiling revealed that CAR T cells became activated, proliferated and produced cytokines in in vitro co-culture with tumor cells and showed reduced cytotoxicity and exhaustive phenotypes after an extended period of expansion.
Overall, we demonstrate that CyTOF technology enables deep functional characterization of CAR T cells by simultaneous detection of surface, cytoplasmic and nuclear markers, supporting advances in CAR T therapy clinical development.

For Research Use Only. Not for use in diagnostic procedures.