SUMMARY Activated T cells differentiate into functional subsets with distinct metabolic programs. Glutaminase (GLS) converts glutamine to glutamate to support the tricarboxylic acid cycle and redox and epigenetic reactions. Here, we identify a key role for GLS in T cell activation and specification. Though GLS deficiency diminished initial T cell activation and proliferation and impaired differentiation of Th17 cells, loss of GLS also increased Tbet to promote differentiation and effector function of CD4 Th1 and CD8 CTL cells. This was associated with altered chromatin accessibility and gene expression, including decreased PIK3IP1 in Th1 cells that sensitized to IL-2-mediated mTORC1 signaling. In vivo, GLS null T cells failed to drive Th17-inflammatory diseases, and Th1 cells had initially elevated function but exhausted over time. Transient GLS inhibition, however, led to increased Th1 and CTL T cell numbers. Glutamine metabolism thus has distinct roles to promote Th17 but constrain Th1 and CTL effector cell differentiation.

provided expertise to develop 18 F nutrient uptake assays. F.X. and M.N.T injected and handled mice for 18 F nutrient uptake assays, and performed and provided expertise for PET imaging and autoradiography. T.H. and W.D.M. performed and provided expertise for intrarenal Renca experiments. R.W.J. and V.T.M generated and provided expertise for PyMT GEMM tumors. R.E.B and C.S.W. generated and provided expertise for AOM/DSS CRC tumors. B.I.R. R.T.O. and M.H.W. generated the pTZeo-EL-thy1.1 transposon construct and engineered MC38 cells using this transposon system. B.I.R, M.Z.M, and A.S. performed in vivo 2NBDG studies. J.E.B. provided expertise in characterizing TAM. A.R.P provided expertise in flow sorting for mRNA transcript analysis. B.I.R. and M.Z.M performed extracellular flux and mRNA transcript experiments. F.M.M. and E.F.M performed and provided expertise in cell staining for light microscopy. E.F.M performed light microscopy and pathologic examination of MC38 tumors. A.A (VU) conducted transcriptomic analysis. B.I.R and M.Z.M. analyzed all data generated in this study. J.C.R. and W.K.R. obtained funding for this study.Data Availability Statement (DAS) All data will be made available upon reasonable request to JCR/WKR. Tumor mRNA transcript data that support the findings of this study have been deposited in Gene Expression Omnibus (GEO) under accession GSE165223. These data are also found in Supplementary Information Table 4. Code Availability Statement (CAS)The code used to support tumor mRNA transcript analysis has been previously published (see methods references) and will be made available upon request to JCR/WKR.

Immune-related adverse events, particularly severe toxicities such as myocarditis, are major challenges to immune checkpoint inhibitor (ICI) utility in anti-cancer therapy1. The pathogenesis of ICI-myocarditis is poorly understood. Pdcd1-/-Ctla4+/-mice recapitulate clinicopathologic features of ICI-myocarditis, including myocardial T cell in ltration2. Single cell RNA/T cell receptor (TCR) sequencing on the cardiac immune in ltrate of Pdcd1-/-Ctla4+/-mice identi ed activated, clonal CD8+ T cells as the dominant cell population. Treatment with anti-CD8, but not anti-CD4, depleting antibodies rescued survival of Pdcd1-/-Ctla4+/-mice. Adoptive transfer of immune cells from mice with myocarditis induced fatal myocarditis in recipients which required CD8+ T cells. Alpha-myosin, a cardiac speci c protein absent from the thymus3,4, was identi ed as the cognate antigen source for three MHC-I restricted TCRs derived from mice with fulminant myocarditis. Peripheral blood T cells from two patients with ICI-myocarditis were expanded by alpha-myosin peptides, and these alpha-myosin expanded T cells shared TCR clonotypes with diseased heart and skeletal muscles, indicating that alpha-myosin may be a clinically important autoantigen in ICI-myocarditis. These studies underscore the critical role for cytotoxic CD8+ T cells, are the rst to identify a candidate autoantigen in ICI-myocarditis and yield new insights into ICI toxicity pathogenesis.Grant 5P30 CA68485-19 and the Shared Instrumentation Grant S10 OD023475-01A1 for the Leica Bond RX. The Vanderbilt VANTAGE Core, including A. Jones and L. Raju, provided technical assistance for this work. VANTAGE is supported in part by a CTSA Grant (5UL1 RR024975-03), the Vanderbilt Ingram Cancer Center (P30 CA68485), the Vanderbilt Vision Center (P30 EY08126) and the NIH/NCRR (G20 RR030956). Figures 1a and 4b were created with BioRender.com.Con ict Interest Disclosure M.L. Axelrod is listed as a coinventor on a provisional patent application for methods to predict therapeutic outcomes using blood-based gene expression patterns, that is owned by Vanderbilt University Medical Center, and is currently unlicensed. S.C. Wei is an employee of Spotlight Therapeutics, a consultant for BioEntre, and an inventor on a patent for a genetic mouse model of autoimmune adverse events and immune checkpoint blockade therapy (PCT/US2019/050551) pending to Board of Regents, The University of Texas System. J.C. Rathmell is a founder, scienti c advisory board member, and stockholder of Sitryx Therapeutics, a scienti c advisory board member and stockholder of Caribou Biosciences, a member of the scienti c advisory board of Nirogy Therapeutics, has consulted for Merck, P zer, and Mitobridge within the past three years, and has received research support from Incyte Corp., Calithera Biosciences, and Tempest Therapeutics. P.B. Ferrell receives research support from Incyte Corporation. D.B.Johnson has served on advisory boards or as a consultant for BMS, Catalyst

The metabolic programs that drive T cell functions are exquisitely sensitive to cell intrinsic and extrinsic factors, allowing T cells to respond in a fine-tuned manner to a variety of immune challenges and conditions. However, many of the factors essential for effector T cell function are perturbed in the tumor microenvironment, where oncogenic mutations drive unrestrained cancer cell growth that leads to excess nutrient consumption, excess waste excretion, and insufficient oxygen delivery. This imposes metabolic constraints on infiltrating cells that result in dysfunction and loss of potential antitumor activity in both naturally occurring as well as tailored T cells introduced as part of immunotherapy. In this review, we highlight the metabolic properties that characterize tumor-infiltrating T cells, the barriers within the metabolic landscape of the tumor microenvironment, and the opportunities and challenges they present in development of new cancer therapeutics.

Recent studies have documented that self-determined choice does indeed enhance performance. However, the precise neural mechanisms underlying this effect are not well understood. We examined the neural correlates of the facilitative effects of self-determined choice using functional magnetic resonance imaging (fMRI). Participants played a game-like task involving a stopwatch with either a stopwatch they selected (self-determined-choice condition) or one they were assigned without choice (forced-choice condition). Our results showed that self-determined choice enhanced performance on the stopwatch task, despite the fact that the choices were clearly irrelevant to task difficulty. Neuroimaging results showed that failure feedback, compared with success feedback, elicited a drop in the vmPFC activation in the forced-choice condition, but not in the self-determined-choice condition, indicating that negative reward value associated with the failure feedback vanished in the self-determined-choice condition. Moreover, the vmPFC resilience to failure in the self-determined-choice condition was significantly correlated with the increased performance. Striatal responses to failure and success feedback were not modulated by the choice condition, indicating the dissociation between the vmPFC and striatal activation pattern. These findings suggest that the vmPFC plays a unique and critical role in the facilitative effects of self-determined choice on performance.