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De Novo Fatty Acid Synthesis Controls the Fate Between Regulatory T and T Helper 17 Cells

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De Novo Fatty Acid Synthesis Controls the Fate Between Regulatory T and T Helper 17 Cells LETTERS De novo fatty acid synthesis controls the fate between regulatory T and T helper 17 cells Luciana Berod1,8, Christin Friedrich1,8, Amrita Nandan1,8, Jenny Freitag1, Stefanie Hagemann1, Kirsten Harmrolfs2, Aline Sandouk1, Christina Hesse1, Carla N Castro1, Heike Bähre3,4, Sarah K Tschirner3, Nataliya Gorinski5, Melanie Gohmert1, Christian T Mayer1, Jochen Huehn6, Evgeni Ponimaskin5, Wolf-Rainer Abraham7, Rolf Müller2, Matthias Lochner1,8 & Tim Sparwasser1,8 Interleukin-17 (IL-17)-secreting T cells of the T helper 17 oxidative phosphorylation as a source of energy3, the induction of the (TH17) lineage play a pathogenic role in multiple inflammatory glycolytic pathway is an active, lineage-decisive step that is required and autoimmune conditions and thus represent a highly for the development of effector T (Teff) cells of the TH1, TH2 and 4 attractive target for therapeutic intervention. We report that TH17 lineages . Hence, in the absence of mTOR, or after treatment inhibition of acetyl-CoA carboxylase 1 (ACC1) restrains the with the mTOR-specific inhibitor rapamycin, the development of Teff 5 formation of human and mouse TH17 cells and promotes the cells is greatly diminished . Along the same line, it has recently been + development of anti-inflammatory Foxp3 regulatory T (Treg) shown that hypoxia-inducible factor 1α (HIF-1α) enhances glycolysis cells. We show that TH17 cells, but not Treg cells, depend on in an mTOR-dependent manner, leading to specific induction of TH17 ACC1-mediated de novo fatty acid synthesis and the underlying cells6. In contrast, interfering with the glycolytic pathway by either glycolytic-lipogenic metabolic pathway for their development. treatment of T cells with rapamycin or absence of HIF-1α selectively 6,7 Although TH17 cells use this pathway to produce phospholipids favors the induction of Treg cells . It has been proposed that Treg cells for cellular membranes, Treg cells readily take up exogenous rely on mitochondrial lipid oxidation to proliferate because activation fatty acids for this purpose. Notably, pharmacologic inhibition of AMP-activated kinase (AMPK), an important metabolic regulator or T cell–specific deletion of ACC1 not only blocks de novo with functions opposing those of mTOR, promotes increased mito- Nature America, Inc. All rights reserved. America, Inc. Nature 4 fatty acid synthesis but also interferes with the metabolic flux chondrial lipid oxidation, which results in an enrichment of Treg cells of glucose-derived carbon via glycolysis and the tricarboxylic in vivo8. However, AMPK not only regulates fatty acid oxidation © 201 acid cycle. In vivo, treatment with the ACC-specific inhibitor (FAO) but also inhibits de novo fatty acid synthesis, a process that soraphen A or T cell–specific deletion of ACC1 in mice has only recently gained attention for its role in the maintenance of + attenuates TH17 cell–mediated autoimmune disease. CD8 T cells and Toll-like receptor–driven maturation and cytokine npg 9,10 Our results indicate fundamental differences between TH17 production by dendritic cells . cells and Treg cells regarding their dependency on ACC1- ACCs are key enzymes for the regulation of the cellular fatty acid mediated de novo fatty acid synthesis, which might be metabolism and exist in humans and other mammals in two isoforms, exploited as a new strategy for metabolic immune modulation ACC1 and ACC2. Both enzymes catalyze the ATP-dependent car- of TH17 cell–mediated inflammatory diseases. boxylation of acetyl-CoA to malonyl-CoA. However, whereas ACC1 is present in the cytosol and is crucial for de novo synthesis of fatty acids, To develop from naive cells into distinct T cell lineages, activated ACC2 is associated with the outer mitochondrial membrane and func- T cells undergo a massive metabolic switch to cope with the demands tions as an important regulator of mitochondrial FAO11. Moreover, both of cell growth and multiple rounds of division1. Notably, T cell pro- enzymes are differentially expressed across tissues, with ACC1 being liferation requires the activity of mammalian target of rapamycin typically present in lipogenic tissues such as liver and adipocytes and (mTOR)-dependent pathways, which results in enhanced aerobic ACC2 mostly expressed in oxidative tissues such as muscle and heart, glycolysis and glutaminolysis as well as the concomitant increase in suggesting a role for these enzymes in controlling the metabolic profile 2 the synthesis of biomolecules . Although activated T cells can still use of different cell types. Because Treg cells have different requirements 1Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research; a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany. 2Helmholtz Institute for Pharmaceutical Research, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany. 3Institute of Pharmacology, Hannover Medical School, Hannover, Germany. 4Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany. 5Institute of Cellular Neurophysiology, Hannover Medical School, Hannover, Germany. 6Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany. 7Department of Chemical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany. 8These authors contributed equally to this work. Correspondence should be addressed to M.L. ([email protected]) or T.S. ([email protected]). Received 24 March; accepted 22 August; published online 5 October 2014; doi:10.1038/nm.3704 NATURE MEDICINE VOLUME 20 | NUMBER 11 | NOVEMBER 2014 1327 LETTERS DMSO SorA a b 4 4 c 50 30 10 38.71 0.2 10 13.13 1.66 3 3 10 10 40 102 102 20 IL-17 + 1 1 + 10 3.59 10 30 0 0 24.85 1 2 3 4 % IL-17 20 1 2 3 4 % Foxp3 Soraphen A 0 10 10 10 10 0 10 10 10 10 10 Foxp3 10 Figure 1 SorA restrains TH17 cell differentiation and 0 0 promotes T cell development. (a) Chemical structure 2 0 0 0 0 0 reg 2 0 0 0 2 4 6 80 40 80 0 2 40 60 80 00 20 100 12 1 160 1 2 of soraphen A (SorA). (b,c) Frequency of IL-17+ and 1 1 14 16 180 200 MSO DMSO D + Foxp3 cells following culture of naive T cells for 4 d SorA (nM) SorA (nM) under TH17-polarizing conditions in the presence of SorA (200 nM) or vehicle (DMSO). Cells were stained d Il17a Il17f Stat3 e 30 300 30 200 for intracellular IL-17 and Foxp3 and were gated on live DMSO ) + CD4 T cells. (b) Representative flow cytometry. Numbers SorA –1 150 represent the percentage of positive cells among total live 20 200 20 100 CD4+ T cells. (c) Percentage of IL-17+ and Foxp3+ cells + 10 100 10 among total live CD4 T cells cultured with SorA (2–200 nM) * 50 or vehicle (DMSO). (d) Gene expression in naive T cells * ** IL-17 (ng ml Relative expression * 0 0 0 0 cultured for 62 h under TH17-polarizing conditions in the presence of SorA (200 nM) or vehicle (DMSO) analyzed by SorA Hif1a Il23r Foxp3 Rorc DMSO real-time PCR. Cycle threshold values were normalized to 60 2.5 6 25 2 * * Actb, and the relative expression ×10 is displayed. 2.0 20 (e) IL-17 production by naive T cells cultured under 40 4 f 1.5 15 TH17-polarizing conditions for 4 d in presence of SorA 1.0 10 DMSOSorA 20SorA nM 200 nM (20 or 200 nM) or vehicle (DMSO), as assessed by ELISA. 20 2 (f) Western blot analysis of total AMPKα and pAMPKα 0.5 * 5 AMPKα Relative expression (Thr172) protein in whole-cell lysates of naive T cells cultured 0 ** 0 0 0 pAMPKα under TH17-polarizing conditions for 4 d in presence of SorA (200 nM) or vehicle (DMSO). Results are representative of ten (b), two (c), four (d) or three (e,f) experiments. Error bars represent s.d. of pooled data (c,d) or triplicates (e). *P < 0.05 and **P < 0.01, Student’s t-test (DMSO versus SorA). + from other Teff lineages in terms of basic metabolic processes, we Foxp3 Treg cells to a similar extent as SorA treatment but at concentra- speculated that direct manipulation of ACC activity can be exploited tions between 100- and 1,000-fold higher (Supplementary Fig. 1c). for immunomodulation of T cell responses. To address this question, We next explored the functional consequences of targeting Nature America, Inc. All rights reserved. America, Inc. Nature + 4 we cultured naive mouse CD4 T cells in vitro under TH17-polarizing ACC on the TH17 versus Treg cell lineage development. Aside from conditions in the presence of soraphen A (SorA) (Fig. 1a), a specific a pronounced downregulation of IL-17 on both the transcriptional 12–14 + © 201 inhibitor of both eukaryotic ACC isozymes . Addition of SorA and translational level (Fig. 1d,e), naive CD4 T cells that differenti- resulted in a dose-dependent reduction in the frequency of IL-17– ated under TH17-polarizing conditions in the presence of SorA also producing cells while strongly favoring the induction of Foxp3- exhibited reduced expression of other TH17 cell–associated genes npg expressing cells (Fig. 1b,c). SorA was active at nanomolar concentra- such as Il17f, Stat3 and Hif1a (Fig. 1d). However, we did not observe tions with a half-maximum effective concentration (EC50) value of downregulation of the gene encoding the TH17 cell–associated tran- approximately 50 nM (Fig. 1c). Notably, a small proportion of the scription factor RORγt (encoded by Rorc). Because SorA treatment SorA-induced Foxp3-expressing cells also produced IL-17 (Fig. 1b), induced high levels of Foxp3 expression (Fig. 1b,d), it is possible that presumably as a consequence of the strong in vitro TH17-polarizing Foxp3 directly antagonized RORγt function and TH17 cell differentia- 16 conditions.
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