Dysfunction of exhausted T cells is enforced by MCT11-mediated lactate metabolism
Ronal M. Peralta, Bingxian Xie, Konstantinos Lontos, Hector Nieves-Rosado, Kellie Spahr, Supriya Joshi, B. Rhodes Ford, Kevin Quann, Andrew Frisch, Victoria Dean, Mary Philbin, Anthony R. Cillo, Sébastien Gingras, Amanda C. Poholek, Larry Kane, Dayana B. Rivadeneira, Greg M. Delgoffe
Abstract
Abstract CD8 + T cells are critical mediators of antitumor immunity but differentiate into a dysfunctional state, known as T cell exhaustion, after persistent T cell receptor stimulation in the tumor microenvironment (TME). Exhausted T (T ex ) cells are characterized by upregulation of coinhibitory molecules and reduced polyfunctionality. T cells in the TME experience an immunosuppressive metabolic environment via reduced levels of nutrients and oxygen and a buildup of lactic acid. Here we show that terminally T ex cells uniquely upregulate Slc16a11 , which encodes monocarboxylate transporter 11 (MCT11). Conditional deletion of MCT11 in T cells reduced lactic acid uptake by T ex cells and improved their effector function. Targeting MCT11 with an antibody reduced lactate uptake specifically in T ex cells, which, when used therapeutically in tumor-bearing mice, resulted in reduced tumor growth. These data support a model in which T ex cells upregulate MCT11, rendering them sensitive to lactic acid present at high levels in the TME.