Distinct Signaling of Coreceptors Regulates Specific Metabolism Pathways and Impacts Memory Development in CAR T Cells.

Abstract

Chimeric antigen receptors (CARs) redirect T cell cytotoxicity against cancer cells, providing a promising approach to cancer immunotherapy. Despite extensive clinical use, the attributes of CAR co-stimulatory domains that impact persistence and resistance to exhaustion of CAR-T cells remain largely undefined. Here, we report the influence of signaling domains of coreceptors CD28 and 4-1BB on the metabolic characteristics of human CAR T cells. Inclusion of 4-1BB in the CAR architecture promoted the outgrowth of CD8(+) central memory T cells that had significantly enhanced respiratory capacity, increased fatty acid oxidation and enhanced mitochondrial biogenesis. In contrast, CAR T cells with CD28 domains yielded effector memory cells with a genetic signature consistent with enhanced glycolysis. These results provide, at least in part, a mechanistic insight into the differential persistence of CAR-T cells expressing 4-1BB or CD28 signaling domains in clinical trials and inform the design of future CAR T cell therapies.