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Sharma P, Guo A, Poudel S, Boada-Romero E, Verbist KC, Palacios G, Immadisetty K, Chen MJ, Haydar D, Mishra A, Peng J, Madan Babu M, Krenciute G, Glazer ES, Green DR. Rapid metabolic regulation of a novel arginine methylation of KCa3.1 attenuates T cell exhaustion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593421. [PMID: 38798680 PMCID: PMC11118966 DOI: 10.1101/2024.05.09.593421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
T cell exhaustion is linked to persistent antigen exposure and perturbed activation events, correlating with poor disease prognosis. Tumor-mediated T cell exhaustion is well documented; however, how the nutrient-deprived tumor niche affects T cell receptor (TCR) activation is largely unclear. We show that methionine metabolism licenses optimal TCR signaling by regulating the protein arginine methylome, and limiting methionine availability during early TCR signaling promotes subsequent T cell exhaustion. We discovered a novel arginine methylation of a Ca 2+ -activated potassium transporter, KCa3.1, prevention of which results in increased Ca 2+ -mediated NFAT1 activation, NFAT1 promoter occupancy, and T cell exhaustion. Furthermore, methionine supplementation reduces nuclear NFAT1 in tumor-infiltrating T cells and augments their anti-tumor activity. These findings demonstrate metabolic regulation of T cell exhaustion determined during TCR engagement.
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Hughes MP. The cellular zeta potential: cell electrophysiology beyond the membrane. Integr Biol (Camb) 2024; 16:zyae003. [PMID: 38291769 DOI: 10.1093/intbio/zyae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/16/2023] [Accepted: 01/06/2024] [Indexed: 02/01/2024]
Abstract
The standard model of the cell membrane potential Vm describes it as arising from diffusion currents across a membrane with a constant electric field, with zero electric field outside the cell membrane. However, the influence of Vm has been shown to extend into the extracellular space where it alters the cell's ζ-potential, the electrical potential measured a few nm from the cell surface which defines how the cell interacts with charged entities in its environment, including ions, molecules, and other cells. The paradigm arising from surface science is that the ζ-potential arises only from fixed membrane surface charge, and has consequently received little interest. However, if the ζ-potential can mechanistically and dynamically change by alteration of Vm, it allows the cell to dynamically alter cell-cell and cell-molecule interactions and may explain previously unexplained electrophysiological behaviours. Whilst the two potentials Vm and ζ are rarely reported together, they are occasionally described in different studies for the same cell type. By considering published data on these parameters across multiple cell types, as well as incidences of unexplained but seemingly functional Vm changes correlating with changes in cell behaviour, evidence is presented that this may play a functional role in the physiology of red blood cells, macrophages, platelets, sperm, ova, bacteria and cancer. Understanding how these properties will improve understanding of the role of electrical potentials and charges in the regulation of cell function and in the way in which cells interact with their environment. Insight The zeta (ζ) potential is the electrical potential a few nm beyond the surface of any suspensoid in water. Whilst typically assumed to arise only from fixed charges on the cell surface, recent and historical evidence shows a strong link to the cell's membrane potential Vm, which the cell can alter mechanistically through the use of ion channels. Whilst these two potentials have rarely been studied simultaneously, this review collates data across multiple studies reporting Vm, ζ-potential, electrical properties of changes in cell behaviour. Collectively, this points to Vm-mediated ζ-potential playing a significant role in the physiology and activity of blood cells, immune response, developmental biology and egg fertilization, and cancer among others.
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Affiliation(s)
- Michael Pycraft Hughes
- Department of Biomedical Engineering/Healthcare Engineering Innovation Centre (HEIC), Khalifa University, Abu Dhabi, UAE
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Zani F, Blagih J, Gruber T, Buck MD, Jones N, Hennequart M, Newell CL, Pilley SE, Soro-Barrio P, Kelly G, Legrave NM, Cheung EC, Gilmore IS, Gould AP, Garcia-Caceres C, Vousden KH. The dietary sweetener sucralose is a negative modulator of T cell-mediated responses. Nature 2023; 615:705-711. [PMID: 36922598 PMCID: PMC10033444 DOI: 10.1038/s41586-023-05801-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/06/2023] [Indexed: 03/17/2023]
Abstract
Artificial sweeteners are used as calorie-free sugar substitutes in many food products and their consumption has increased substantially over the past years1. Although generally regarded as safe, some concerns have been raised about the long-term safety of the consumption of certain sweeteners2-5. In this study, we show that the intake of high doses of sucralose in mice results in immunomodulatory effects by limiting T cell proliferation and T cell differentiation. Mechanistically, sucralose affects the membrane order of T cells, accompanied by a reduced efficiency of T cell receptor signalling and intracellular calcium mobilization. Mice given sucralose show decreased CD8+ T cell antigen-specific responses in subcutaneous cancer models and bacterial infection models, and reduced T cell function in models of T cell-mediated autoimmunity. Overall, these findings suggest that a high intake of sucralose can dampen T cell-mediated responses, an effect that could be used in therapy to mitigate T cell-dependent autoimmune disorders.
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Affiliation(s)
- Fabio Zani
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
| | - Julianna Blagih
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
- University of Montreal, Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada.
| | - Tim Gruber
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München and German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Michael D Buck
- Immunobiology Laboratory, The Francis Crick Institute, London, UK
| | - Nicholas Jones
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - Marc Hennequart
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | - Clare L Newell
- National Physical Laboratory, Teddington, UK
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, UK
| | - Steven E Pilley
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | - Pablo Soro-Barrio
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Gavin Kelly
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Nathalie M Legrave
- Metabolomics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Eric C Cheung
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK
| | | | - Alex P Gould
- Laboratory of Physiology and Metabolism, The Francis Crick Institute, London, UK
| | - Cristina Garcia-Caceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München and German Center for Diabetes Research (DZD), Neuherberg, Germany
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Karen H Vousden
- p53 and Metabolism Laboratory, The Francis Crick Institute, London, UK.
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Zegarra-Moran O, Rasola A, Rugolo M, Porcelli AM, Rossi B, Galietta LJV. HIV-1 Nef Expression Inhibits the Activity of a Ca2+-Dependent K+ Channel Involved in the Control of the Resting Potential in CEM Lymphocytes. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.9.5359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The HIV-1 Nef protein plays an important role in the development of the pathology associated with AIDS. Despite various studies that have dealt with different aspects of Nef function, the complete mechanism by which it alters the physiology of infected cells remains to be established. Nef can associate with cell membranes, therefore supporting the hypothesis that it might interact with membrane proteins as ionic channels and modify their electrical properties. By using the patch-clamp technique, we found that Nef expression determines a 25-mV depolarization of lymphoblastoid CEM cells. Both charybdotoxin (CTX) and the membrane-permeable Ca2+ chelator BAPTA/AM depolarized the membrane of native cells without modifying that of Nef-transfected cells. These data suggested that the resting potential in native CEM cells is settled by a CTX- and Ca2+-sensitive K+ channel (KCa,CTX), whose activity is absent in Nef-expressing cells. This was confirmed by direct measurements of whole-cell KCa,CTX currents. Single-channel recordings on excised patches showed that a KCa,CTX channel of 35 pS with a half-activation near 400 nM Ca2+ was present in both native and Nef-transfected cells. The measurements of free intracellular Ca2+ were not different in the two cell lines, but Nef-transfected cells displayed an increased Ca2+ content in ionomycin-sensitive stores. Taken together, these results indicate that Nef expression alters the resting membrane potential of the T lymphocyte cell line by inhibiting a KCa,CTX channel, possibly by intervening in the regulation of intracellular Ca2+ homeostasis.
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Affiliation(s)
- Olga Zegarra-Moran
- *Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova, Italy
| | - Andrea Rasola
- †Unité de Recherches en Immunologie Cellulaire et Moléculaire, Institut National de la Santé et de la Recherche Médicale, Unit 364, Nice, France; and
| | - Michela Rugolo
- ‡Laboratorio di Biochimica, Dipartimento di Biologia, Università di Bologna, Bologna, Italy
| | - Anna M. Porcelli
- ‡Laboratorio di Biochimica, Dipartimento di Biologia, Università di Bologna, Bologna, Italy
| | - Bernard Rossi
- †Unité de Recherches en Immunologie Cellulaire et Moléculaire, Institut National de la Santé et de la Recherche Médicale, Unit 364, Nice, France; and
| | - Luis J. V. Galietta
- *Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova, Italy
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