Upregulated ethanolamine phospholipid synthesis via selenoprotein I is required for effective metabolic reprogramming during T cell activation

The selenoprotein family includes 25 members, many of which are antioxidant or redox regulating enzymes. A unique member of this family is Selenoprotein I (SELENOI), which does not catalyze redox reactions, but instead is an ethanolamine phosphotransferase (Ept). In fact, the characteristic selenocysteine residue that defines selenoproteins lies far outside of the catalytic domain of SELENOI. Furthermore, data using recombinant SELENOI lacking the selenocysteine residue have suggested that the selenocysteine amino acid is not directly involved in the Ept reaction. SELENOI is involved in two different pathways for the synthesis of phosphatidylethanolamine (PE) and plasmenyl PE, which are constituents of cellular membranes. Ethanolamine phospholipid synthesis has emerged as an important process for metabolic reprogramming that occurs in pluripotent stem cells and proliferating tumor cells, and this review discusses roles for upregulation of SELENOI during T cell activation, proliferation, and differentiation. SELENOI deficiency lowers but does not completely diminish de novo synthesis of PE and plasmenyl PE during T cell activation. Interestingly, metabolic reprogramming in activated SELENOI deficient T cells is impaired and this reduces proliferative capacity while favoring tolerogenic to pathogenic phenotypes that arise from differentiation. The implications of these findings are discussed related to vaccine responses, autoimmunity, and cell-based therapeutic approaches.

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Hypoxia is a dominant remodeler of the CD8+ T cell surface proteome relative to activation and regulatory T cell-mediated suppression

10.1101/2021.06.07.447379 ◽

2021 ◽

Author(s):

James Robert Byrnes ◽

Amy M Weeks ◽

Julia Carnevale ◽

Eric Shifrut ◽

Lisa Kirkemo ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Surface ◽

T Cell Activation ◽

Cell Activation ◽

Cell Function ◽

Metabolic Reprogramming ◽

T Cell Function ◽

Human T Cells ◽

Surface Proteome

Immunosuppressive factors in the tumor microenvironment (TME) impair T cell function and limit the anti-tumor immune response. T cell surface receptors that influence interactions and function in the TME are already proven targets for cancer immunotherapy. However, surface proteome remodeling of primary human T cells in response to suppressive forces in the TME has never been characterized systematically. Using a reductionist cell culture approach with primary human T cells and SILAC-based quantitative cell surface capture glycoproteomics, we examined how two immunosuppressive TME factors, regulatory T cells (Tregs) and hypoxia, globally affect the activated CD8+ surface proteome (surfaceome). Surprisingly, the CD8+/Treg co-culture only modestly affected the CD8+ surfaceome, but did reverse several activation-induced surfaceomic changes. In contrast, hypoxia dramatically altered the CD8+ surfaceome in a manner consistent with both metabolic reprogramming and induction of an immunosuppressed state. The CD4+ T cell surfaceome similarly responded to hypoxia, revealing a novel hypoxia-induced surface receptor program. Our findings are consistent with the premise that hypoxic environments create a metabolic challenge for T cell activation, which may underlie the difficulty encountered in treating solid tumors with immunotherapies. Together, the data presented here provide insight into how suppressive TME factors remodel the T cell surfaceome and represent a valuable resource to inform future therapeutic efforts to enhance T cell function in the TME.

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Mechanosensing through YAP controls T cell activation and metabolism

Journal of Experimental Medicine ◽

10.1084/jem.20200053 ◽

2020 ◽

Vol 217 (8) ◽

Cited By ~ 2

Author(s):

Kevin P. Meng ◽

Fatemeh S. Majedi ◽

Timothy J. Thauland ◽

Manish J. Butte

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Viral Infections ◽

Autoimmune Diabetes ◽

Tissue Mechanics ◽

Effector T Cells ◽

Metabolic Reprogramming ◽

Dependent Manner

Upon immunogenic challenge, lymph nodes become mechanically stiff as immune cells activate and proliferate within their encapsulated environments, and with resolution, they reestablish a soft baseline state. Here we show that sensing these mechanical changes in the microenvironment requires the mechanosensor YAP. YAP is induced upon activation and suppresses metabolic reprogramming of effector T cells. Unlike in other cell types in which YAP promotes proliferation, YAP in T cells suppresses proliferation in a stiffness-dependent manner by directly restricting the translocation of NFAT1 into the nucleus. YAP slows T cell responses in systemic viral infections and retards effector T cells in autoimmune diabetes. Our work reveals a paradigm whereby tissue mechanics fine-tune adaptive immune responses in health and disease.

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The Swing of Lipids at Peroxisomes and Endolysosomes in T Cell Activation

International Journal of Molecular Sciences ◽

10.3390/ijms21082859 ◽

2020 ◽

Vol 21 (8) ◽

pp. 2859

Author(s):

Sara G. Dosil ◽

Amelia Rojas-Gomez ◽

Francisco Sánchez-Madrid ◽

Noa B. Martín-Cófreces

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Synapse Formation ◽

Cell Receptor ◽

Metabolic Reprogramming ◽

Mitochondrial Activity ◽

Oxygen Species ◽

Immune Synapse ◽

Antigen Presenting

The immune synapse (IS) is a well-known intercellular communication platform, organized at the interphase between the antigen presenting cell (APC) and the T cell. After T cell receptor (TCR) stimulation, signaling from plasma membrane proteins and lipids is amplified by molecules and downstream pathways for full synapse formation and maintenance. This secondary signaling event relies on intracellular reorganization at the IS, involving the cytoskeleton and components of the secretory/recycling machinery, such as the Golgi apparatus and the endolysosomal system (ELS). T cell activation triggers a metabolic reprogramming that involves the synthesis of lipids, which act as signaling mediators, and an increase of mitochondrial activity. Then, this mitochondrial activity results in elevated reactive oxygen species (ROS) production that may lead to cytotoxicity. The regulation of ROS levels requires the concerted action of mitochondria and peroxisomes. In this review, we analyze this reprogramming and the signaling implications of endolysosomal, mitochondrial, peroxisomal, and lipidic systems in T cell activation.

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Ionizing Radiation Impairs T Cell Activation by Affecting Metabolic Reprogramming

International Journal of Biological Sciences ◽

10.7150/ijbs.12009 ◽

2015 ◽

Vol 11 (7) ◽

pp. 726-736 ◽

Cited By ~ 19

Author(s):

Heng-Hong Li ◽

Yi-wen Wang ◽

Renxiang Chen ◽

Bin Zhou ◽

Jonathan D. Ashwell ◽

...

Keyword(s):

T Cell ◽

Ionizing Radiation ◽

T Cell Activation ◽

Cell Activation ◽

Metabolic Reprogramming

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Acly promotes metabolic reprogramming and induction of IRF4 during early CD8 + T cell activation

Cytometry Part A ◽

10.1002/cyto.a.24294 ◽

2020 ◽

Author(s):

Nicole Vaughn ◽

David L. Haviland

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Cd8 T Cell ◽

Metabolic Reprogramming

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657 Characterization and therapeutic targeting of a tumor-associated tolerogenic DC subpopulation driven by SREBP2 and the mevalonate metabolic pathway

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.657 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A685-A685

Author(s):

Michael Plebanek ◽

Nicholas DeVito ◽

Fang Liu ◽

Balamayooran Theivanthiran ◽

Georgia Beasley ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

T Cell Activation ◽

Immune Evasion ◽

Cell Activation ◽

Mevalonate Pathway ◽

Metabolic Reprogramming ◽

Tissue Specimens ◽

Tolerogenic Dcs

BackgroundConventional dendritic cells (DCs) are essential mediators of anti-tumor immunity and the efficacy of anti-PD-1 checkpoint immunotherapies.1 Recent studies suggest that tumor-mediated development of a sub-population of tolerogenic DCs plays an important role in immune evasion.2 3 Metabolic reprogramming regulates tolerogenic DCs in the tumor microenvironment (TME).4 5 Activation of DCs leads to rewiring of cDC metabolism towards glycolysis to support T cell activation while tolerogenic DCs display enhanced fatty acid oxidation.6 Related to DC metabolic alterations, tumor-associated DCs (TADCs) are enriched in lipids and have a reduced capacity to present antigen to T cells. Lipid homeostasis is maintained through a complex network of transcription factors including sterol regulatory element-binding protein-2 (SREBP2) which drives the expression of mevalonate pathway genes.7 The identification of those tumor-controlled pathways that regulate tolerogenic DCs in the TME is expected to lead to the discovery of a novel family of immunotherapeutic targets.MethodsWe use transgenic mouse models of melanoma, sentinel lymph node (LN) tissue specimens derived from melanoma patients, single-cell RNA sequencing (scRNAseq), and flow cytometry-based metabolic assays to identify novel tumor-associated regulatory programs amongst different sub-populations of conventional DCs in the TME.Results scRNAseq of DCs isolated from the tumor-draining LN (TDLN) of a BRAFV600EPTEN-/- transgenic melanoma model revealed critical genetic differences in distinct DC sub-populations. We observed a migratory DC subset enriched in the expression of numerous immunoregulatory genes and identified CD63 as a surface marker to distinguish this DC subset from other conventional cDC1s and cDC2s. Further studies demonstrated CD63+ DCs to suppress T cell activation and promote CD4+FOXP3+ regulatory T cell (Treg) differentiation. Relative to other cDC subsets, CD63+ DCs overexpress genes of the mevalonate pathway leading to increased lipid content. Treatment of melanoma-bearing mice with a pharmacologic inhibitor of SREBP2 leads to a significant reduction in CD63+ DCs in the TDLN and reduced Tregs, resulting in suppressed tumor growth. Importantly, scRNAseq of DCs isolated from sentinel LNs of melanoma patients reveal that this population is conserved in humans.ConclusionsLipid homeostasis in TADCs is a major determinant of their metabolic state, but despite significant advances, the molecular pathways regulating tolerogenic DCs have remained poorly understood. Collectively, this data demonstrates an important role of the mevalonate pathway in driving a tolerogenic DC program and highlights the therapeutic targeting of SREBP2 and DC lipid metabolism as a promising approach to overcoming immune tolerance in the TME and boosting immunotherapy responses.ReferencesGardner A, Ruffell B. Dendritic cells and cancer immunity. Trends Immunol 2016;37:855–865. doi:10.1016/j.it.2016.09.006DeVito NC, Plebanek MP, Theivanthiran B, Hanks BA. Role of tumor-mediated dendritic cell tolerization in immune evasion. Front Immunol 2019;10:2876. doi:10.3389/fimmu.2019.02876Gerhard GM, Bill R, Messemaker M, Klein AM, Pittet MJ. Tumor-infiltrating dendritic cell states are conserved across solid human cancers. J Exp Med 2021;218. doi:10.1084/jem.20200264Plebanek MP, Sturdivant M, DeVito NC, Hanks BA. Role of dendritic cell metabolic reprogramming in tumor immune evasion. Int Immunol 2020;32:485–491. doi:10.1093/intimm/dxaa036Wculek SK, Khouili SC, Priego E, Heras-Murillo I, Sancho D. Metabolic control of dendritic cell functions: digesting information. Front Immunol 2019;10:775. doi:10.3389/fimmu.2019.00775Zhao F. et al. Paracrine Wnt5a-beta-Catenin signaling triggers a metabolic program that drives dendritic cell tolerization. Immunity 2018;48:147-+, doi:10.1016/j.immuni.2017.12.004Xue L. et al. Targeting SREBP-2-Regulated mevalonate metabolism for cancer therapy. Front Oncol 2020;10:1510, doi:10.3389/fonc.2020.01510Ethics ApprovalCollection of human tissue specimens was approved by the Duke Institutional Review Board under the title Immune Markers of Sentinel Nodes in Melanoma and the protocol number Pro00090678. All patients gave informed consent prior to participating in the study. All experiments involving animals were approved by the Duke University Institutional Animal Care and Use Committee (IACUC) under protocol number A174-18-07

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Role of Bladder Cancer Metabolic Reprogramming in the Effectiveness of Immunotherapy

Cancers ◽

10.3390/cancers13020288 ◽

2021 ◽

Vol 13 (2) ◽

pp. 288

Author(s):

Mathijs P. Scholtes ◽

Florus C. de Jong ◽

Tahlita C. M. Zuiverloon ◽

Dan Theodorescu

Keyword(s):

T Cell ◽

Tumor Microenvironment ◽

T Cell Activation ◽

Cell Activation ◽

Checkpoint Inhibitors ◽

Metabolic Reprogramming ◽

Host Cells ◽

T Cell Therapy ◽

Literature Searches ◽

The Impact

Metabolic reprogramming (MR) is an upregulation of biosynthetic and bioenergetic pathways to satisfy increased energy and metabolic building block demands of tumors. This includes glycolytic activity, which deprives the tumor microenvironment (TME) of nutrients while increasing extracellular lactic acid. This inhibits cytotoxic immune activity either via direct metabolic competition between cancer cells and cytotoxic host cells or by the production of immune-suppressive metabolites such as lactate or kynurenine. Since immunotherapy is a major treatment option in patients with metastatic urothelial carcinoma (UC), MR may have profound implications for the success of such therapy. Here, we review how MR impacts host immune response to UC and the impact on immunotherapy response (including checkpoint inhibitors, adaptive T cell therapy, T cell activation, antigen presentation, and changes in the tumor microenvironment). Articles were identified by literature searches on the keywords or references to “UC” and “MR”. We found several promising therapeutic approaches emerging from preclinical models that can circumvent suppressive MR effects on the immune system. A select summary of active clinical trials is provided with examples of possible options to enhance the effectiveness of immunotherapy. In conclusion, the literature suggests manipulating the MR is feasible and may improve immunotherapy effectiveness in UC.

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Potentiating the anti-tumor response of tumor infiltrated T cells by NAD+ supplementation

10.1101/2020.03.21.001123 ◽

2020 ◽

Author(s):

Yuetong Wang ◽

Fei Wang ◽

Lihua Wang ◽

Shizhen Qiu ◽

Yufeng Yao ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Large Scale ◽

Cell Activation ◽

Metabolic Reprogramming ◽

Metabolic Inhibitor ◽

Therapeutic Effects ◽

Nicotinamide Phosphoribosyltransferase ◽

Car T

AbstractTumor immunotherapies have provided clinical benefits, yet great potential remains for optimizing therapeutic effects. Here, we show that low NAD+ levels restrict the function of tumor infiltrating T lymphocytes (TILs). TILs harvested from human ovarian tumor tissues showed decreased NAD+ levels compared with T cells from paired peripheral blood samples. The combination of whole-genome CRISPR and large-scale metabolic inhibitor screens implicated the NAD+ biosynthesis enzyme nicotinamide phosphoribosyltransferase (NAMPT) is required for T cell activation. Further isotopic labeling and LC-MS studies confirmed that NAD+ depletion suppressed mitochondrial energy biosynthesis in T cells. Excitingly, NAD+ supplementation significantly enhanced the tumor cell-killing efficacy of CAR-T cells ex vivo, and extended animal survive in both adoptive CAR-T model and immune checkpoint blockade treatment models in vivo. This study demonstrates an over-the-counter nutrient supplement NAD+ could robustly boost the efficacy of T cell-based immunotherapy and provides insights into the cellular basis of T cell metabolic reprogramming in treating cancers.One Sentence SummaryNAD+ supplementation during cancer immunotherapies significantly enhances T cell activation and tumor killing capacity.

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Abstract 621: Homocysteine Activates T Cells by Enhancing Endoplasmic Reticulum-mitochondria Coupling and Increasing Mitochondrial Respiration

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.35.suppl_1.621 ◽

2015 ◽

Vol 35 (suppl_1) ◽

Author(s):

Juan Feng ◽

Xian Wang

Keyword(s):

Cell Proliferation ◽

T Cells ◽

T Cell ◽

T Cell Activation ◽

Mitochondrial Respiration ◽

Cell Activation ◽

Metabolic Reprogramming ◽

T Cell Proliferation ◽

Mitochondrial Ros ◽

Ifn Γ

Hyperhomocysteinemia (HHcy) accelerates atherosclerosis by affecting the immuno-inflammatory response, increasing proliferation and stimulating cytokine secretion in T cells. However, whether homocysteine (Hcy) activation of T cells is associated with metabolic reprogramming is unclear. Here, we showed that Hcy (50 μM, 24 hr)-stimulated splenic T-cell proliferation in mice was accompanied by increased levels of mitochondrial reactive oxygen species (ROS) by 23.25±2.27%, calcium overload, increased mitochondrial mass by 24.29±7.97% and increased respiration. Inhibiting mitochondrial ROS levels and calcium signals or blocking mitochondrial respiration largely blunted Hcy-induced T-cell activation. Hcy also enhanced endoplasmic reticulum (ER) stress in T cells. Inhibiting ER stress with 4-phenylbutyric acid or mitochondrial respiration by rotenone blocked Hcy-induced T-cell proliferation and interferon-γ (IFN-γ) secretion. Mechanistically, Hcy treatment increased ER-mitochondria coupling as revealed by structured illumination microscopy and elevated expression of tethering proteins MFN2, Gpx7, and ERP44. Uncoupling ER and mitochondria by the microtubule inhibitor nocodazole attenuated Hcy-stimulated mitochondrial ROS production, calcium overload, mitochondrial membrane potential, IFN-γ secretion and T-cell proliferation; thus, juxtaposition of ER and mitochondria is required for Hcy-promoted mitochondrial function and T-cell activation. In conclusion, Hcy promotes T-cell proliferation and IFN-γ secretion by inducing metabolic reprogramming via regulating ER-mitochondrial coupling. Our results highlight the importance of metabolic regulation in T-cell activation and shed new light on understanding the pathogenesis of HHcy-accelerated atherosclerosis.

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