Evaluating Multimodal Functionality of Chimeric Antigen Receptor T Cells at Single-Cell Resolution through Optofluidics Analysis.

Adoptive T-cell therapy is a novel treatment paradigm in which autologous T cells are genetically modified to express a tumor-targeting chimeric antigen receptor (CAR) prior to ex vivo expansion and re-infusion into the patient. Despite remarkable demonstrations of anti-tumor potency in patients with advanced hematological malignancies, long-lasting responses fail to manifest in a substantial fraction of cases. Although several idiosyncratic factors may contribute to the variability in clinical outcomes, there is mounting evidence that the percentage of polyfunctional T cells in the pre-infusion CAR-T cell product strongly correlates with the durability of cancer remission. Unfortunately, standard evaluations of CAR-T cell products currently rely on bulk population measurements or terminal assays, limiting the ability to isolate and study sub-populations with heightened functional properties. Here, we demonstrate a workflow that leverages an optofluidics platform to evaluate both the cytokine secretion profile and activation via CD137 expression of individual CAR-T cells, which can be optionally combined with cytotoxic activity assessment. Cells exhibiting the greatest degree of multimodal functionality can be isolated for further analyses to inform the design of next-generation CAR-T cell therapies.