Single-cell analysis by mass cytometry reveals metabolic states of early-activated CD8+ T cells during the primary immune response

Memory T cells are thought to rely on oxidative phosphorylation and short-lived effector T cells on glycolysis. Here, we investigated how T cells arrive at these states during an immune response. To understand the metabolic state of rare, early-activated T cells, we adapted mass cytometry to quantify metabolic regulators at single-cell resolution in parallel with cell signaling, proliferation, and effector function. We interrogated CD8+ T cell activation in vitro and in response to Listeria monocytogenes infection in vivo. This approach revealed a distinct metabolic state in early-activated T cells characterized by maximal expression of glycolytic and oxidative metabolic proteins. Cells in this transient state were most abundant 5 days post-infection before rapidly decreasing metabolic protein expression. Analogous findings were observed in chimeric antigen receptor (CAR) T cells interrogated longitudinally in advanced lymphoma patients. Our study demonstrates the utility of single-cell metabolic analysis by mass cytometry to identify metabolic adaptations of immune cell populations in vivo and provides a resource for investigations of metabolic regulation of immune responses across a variety of applications. [Display omitted] •A mass cytometry approach quantifies metabolic proteins in single cells in vivo•Early-activated T cells exhibit simultaneous peak oxidative and glycolytic activity•CD8+ T cells transit through this transient state prior to differentiation•CAR T cells exhibit an analogous transient program upon infusion into patients Levine, Hiam-Galvez, et al. develop a mass-cytometry-based approach to quantify metabolic protein expression in single cells in vivo, revealing a distinct metabolic state early after CD8+ T cell activation characterized by simultaneous expression of glycolytic and oxidative proteins. This approach provides a resource for the study of metabolic regulation across a variety of applications.