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Al-Kuraishy HM, Sulaiman GM, Jabir MS, Mohammed HA, Al-Gareeb AI, Albukhaty S, Klionsky DJ, Abomughaid MM. Defective autophagy and autophagy activators in myasthenia gravis: a rare entity and unusual scenario. Autophagy 2024; 20:1473-1482. [PMID: 38346408 PMCID: PMC11210922 DOI: 10.1080/15548627.2024.2315893] [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: 11/30/2023] [Accepted: 02/02/2024] [Indexed: 03/07/2024] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction (NMJ) that results from autoantibodies against nicotinic acetylcholine receptors (nAchRs) at NMJs. These autoantibodies are mainly originated from autoreactive B cells that bind and destroy nAchRs at NMJs preventing nerve impulses from activating the end-plates of skeletal muscle. Indeed, immune dysregulation plays a crucial role in the pathogenesis of MG. Autoreactive B cells are increased in MG due to the defect in the central and peripheral tolerance mechanisms. As well, autoreactive T cells are augmented in MG due to the diversion of regulatory T (Treg) cells or a defect in thymic anergy leading to T cell-mediated autoimmunity. Furthermore, macroautophagy/autophagy, which is a conserved cellular catabolic process, plays a critical role in autoimmune diseases by regulating antigen presentation, survival of immune cells and cytokine-mediated inflammation. Abnormal autophagic flux is associated with different autoimmune disorders. Autophagy regulates the connection between innate and adaptive immune responses by controlling the production of cytokines and survival of Tregs. As autophagy is involved in autoimmune disorders, it may play a major role in the pathogenesis of MG. Therefore, this mini-review demonstrates the potential role of autophagy and autophagy activators in MG.Abbreviations: Ach, acetylcholine; Breg, regulatory B; IgG, immunoglobulin G; MG, myasthenia gravis; NMJ, neuromuscular junction; ROS, reactive oxygen species; Treg, regulatory T; Ubl, ubiquitin-like.
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Affiliation(s)
- Hayder M. Al-Kuraishy
- Department of Clinical Pharmacology and Medicine, College of Medicine, Mustansiriyah University, Baghdad, Iraq
| | | | - Majid S. Jabir
- Department of Applied Sciences, University of Technology, Baghdad, Iraq
| | - Hamdoon A. Mohammed
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Qassim University, Qassim, Saudi Arabia
- Department of Pharmacognosy and Medicinal Plants, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | | | - Salim Albukhaty
- Department of Chemistry, College of Science, University of Misan, Maysan, Iraq
| | | | - Mosleh M. Abomughaid
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, University of Bisha, Bisha, Saudi Arabia
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Feng R, Liu C, Cui Z, Liu Z, Zhang Y. Sphingosine 1-phosphate combining with S1PR4 promotes regulatory T cell differentiation related to FAO through Nrf2/PPARα. Scand J Immunol 2023; 98:e13322. [PMID: 39007959 DOI: 10.1111/sji.13322] [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: 12/21/2022] [Revised: 07/01/2023] [Accepted: 08/02/2023] [Indexed: 07/16/2024]
Abstract
Metabolism and metabolic processes have long been considered to shape the tumour immunosuppressive microenvironment. Recent research has demonstrated that T regulatory cells (Tregs) display high rates of fatty acid oxidation (FAO) and a relatively low rate of glycolysis. Sphingosine 1-phosphate (S1P), which is a G protein signalling activator involved in immune regulation and FAO modulation, has been implicated in Treg differentiation. However, the precise relation between Treg differentiation and S1P remains unclear. In this study, we isolated naïve CD4+ T cells from the spleens of 6-8-week-old BALB/c mice using magnetic bead sorting, which was used in our study for Treg differentiation. S1P stimulation was performed during Treg differentiation. We examined the oxygen consumption and palmitic acid metabolism of the differentiated Tregs and evaluated the expression levels of various proteins, including Nrf2, CPT1A, Glut1, ACC1 and PPARα, through Western blotting. Our results demonstrate that S1P promotes Treg differentiation and enhances FAO, and that the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and peroxisome proliferator-activated receptor α (PPARα) is upregulated. Furthermore, Nrf2 or PPARα knockdown dampened the Treg differentiation and FAO that were promoted by S1P, confirming that S1P can bind with S1PR4 to promote Treg differentiation through the Nrf2/PPARα signalling pathway, which may be related to FAO facilitation.
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Affiliation(s)
- Rui Feng
- Department of Hepatobiliary Surgery, Tianjin First Central Hospital, Tianjin, China
| | - Chuang Liu
- Department of Hepatobiliary Surgery, Tianjin First Central Hospital, Tianjin, China
| | - Zilin Cui
- Department of Hepatobiliary Surgery, Tianjin First Central Hospital, Tianjin, China
| | - Zirong Liu
- Department of Hepatobiliary Surgery, Tianjin First Central Hospital, Tianjin, China
| | - Yamin Zhang
- Department of Hepatobiliary Surgery, Tianjin First Central Hospital, Tianjin, China
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Bridgeman CJ, Shah SA, Oakes RS, Jewell CM. Dissecting regulatory T cell expansion using polymer microparticles presenting defined ratios of self-antigen and regulatory cues. Front Bioeng Biotechnol 2023; 11:1184938. [PMID: 37441198 PMCID: PMC10334287 DOI: 10.3389/fbioe.2023.1184938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/12/2023] [Indexed: 07/15/2023] Open
Abstract
Biomaterials allow for the precision control over the combination and release of cargo needed to engineer cell outcomes. These capabilities are particularly attractive as new candidate therapies to treat autoimmune diseases, conditions where dysfunctional immune cells create pathogenic tissue environments during attack of self-molecules termed self-antigens. Here we extend past studies showing combinations of a small molecule immunomodulator co-delivered with self-antigen induces antigen-specific regulatory T cells. In particular, we sought to elucidate how different ratios of these components loaded in degradable polymer particles shape the antigen presenting cell (APC) -T cell interactions that drive differentiation of T cells toward either inflammatory or regulatory phenotypes. Using rapamycin (rapa) as a modulatory cue and myelin self-peptide (myelin oligodendrocyte glycoprotein- MOG) - self-antigen attacked during multiple sclerosis (MS), we integrate these components into polymer particles over a range of ratios and concentrations without altering the physicochemical properties of the particles. Using primary cell co-cultures, we show that while all ratios of rapa:MOG significantly decreased expression of co-stimulation molecules on dendritic cells (DCs), these levels were insensitive to the specific ratio. During co-culture with primary T cell receptor transgenic T cells, we demonstrate that the ratio of rapa:MOG controls the expansion and differentiation of these cells. In particular, at shorter time points, higher ratios induce regulatory T cells most efficiently, while at longer time points the processes are not sensitive to the specific ratio. We also found corresponding changes in gene expression and inflammatory cytokine secretion during these times. The in vitro results in this study contribute to in vitro regulatory T cell expansion techniques, as well as provide insight into future studies to explore other modulatory effects of rapa such as induction of maintenance or survival cues.
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Affiliation(s)
- Christopher J. Bridgeman
- Fischell Department of Bioengineering, University of Maryland College Park, Baltimore, MD, United states
| | - Shrey A. Shah
- Fischell Department of Bioengineering, University of Maryland College Park, Baltimore, MD, United states
| | - Robert S. Oakes
- Fischell Department of Bioengineering, University of Maryland College Park, Baltimore, MD, United states
- United States Department of Veterans Affairs, Baltimore, MD, United states
| | - Christopher M. Jewell
- Fischell Department of Bioengineering, University of Maryland College Park, Baltimore, MD, United states
- United States Department of Veterans Affairs, Baltimore, MD, United states
- Robert E Fischell Institute of Biomedical Devices, University of Maryland College Park, Baltimore, MD, United states
- Department of Microbiology and Immunology, University of Maryland Medical School, Baltimore, MD, United states
- Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD, United states
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GOT1 constrains T H17 cell differentiation, while promoting iT reg cell differentiation. Nature 2023; 614:E1-E11. [PMID: 36726001 DOI: 10.1038/s41586-022-05602-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/25/2022] [Indexed: 02/03/2023]
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Bierhansl L, Hartung HP, Aktas O, Ruck T, Roden M, Meuth SG. Thinking outside the box: non-canonical targets in multiple sclerosis. Nat Rev Drug Discov 2022; 21:578-600. [PMID: 35668103 PMCID: PMC9169033 DOI: 10.1038/s41573-022-00477-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2022] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system that causes demyelination, axonal degeneration and astrogliosis, resulting in progressive neurological disability. Fuelled by an evolving understanding of MS immunopathogenesis, the range of available immunotherapies for clinical use has expanded over the past two decades. However, MS remains an incurable disease and even targeted immunotherapies often fail to control insidious disease progression, indicating the need for new and exceptional therapeutic options beyond the established immunological landscape. In this Review, we highlight such non-canonical targets in preclinical MS research with a focus on five highly promising areas: oligodendrocytes; the blood-brain barrier; metabolites and cellular metabolism; the coagulation system; and tolerance induction. Recent findings in these areas may guide the field towards novel targets for future therapeutic approaches in MS.
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Affiliation(s)
- Laura Bierhansl
- Department of Neurology, Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Hans-Peter Hartung
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Orhan Aktas
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- German Center of Diabetes Research, Partner Düsseldorf, Neuherberg, Germany
| | - Sven G Meuth
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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Guo Y, Sun D, Zhang Y, Yu X, Fang Y, Lv C, Zhang Q, Zhu Y, Qiao S, Xia Y, Wei Z, Dai Y. The neuropeptide cortistatin attenuates Th17 cell response through inhibition of glycolysis via GHSR1. Int Immunopharmacol 2022; 108:108843. [DOI: 10.1016/j.intimp.2022.108843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/18/2022] [Accepted: 05/04/2022] [Indexed: 11/27/2022]
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Impact of Lipid Metabolism on Antitumor Immune Response. Cancers (Basel) 2022; 14:cancers14071850. [PMID: 35406621 PMCID: PMC8997602 DOI: 10.3390/cancers14071850] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary One of the causes of failure of anticancer therapies is the reprogramming of lipid metabolism. Cells of innate and adaptive immunity present in the tumor microenvironment can be affected by this metabolic switch and thus present changes in their anti- or protumor phenotype. In this review, modifications induced by lipid metabolism will be described for innate immune cells, such as macrophages, dendritic cells and MDSCs, and also for adaptive immune cells, such as CD4+ and CD8+ T cells and B cells. Finally, antitumor therapeutic strategies targeting lipid metabolism will be presented. Abstract Over the past decade, metabolic reprogramming has been defined as a hallmark of cancer. More recently, a large number of studies have demonstrated that metabolic reprogramming can modulate the differentiation and functions of immune cells, and thus modify the antitumor response. Increasing evidence suggests that modified energy metabolism could be responsible for the failure of antitumor immunity. Indeed, tumor-infiltrating immune cells play a key role in cancer, and metabolic switching in these cells has been shown to help determine their phenotype: tumor suppressive or immune suppressive. Recent studies in the field of immunometabolism focus on metabolic reprogramming in the tumor microenvironment (TME) by targeting innate and adaptive immune cells and their associated anti- or protumor phenotypes. In this review, we discuss the lipid metabolism of immune cells in the TME as well as the effects of lipids; finally, we expose the link between therapies and lipid metabolism.
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Shen D, Liu K, Wang H, Wang H. Autophagy modulation in multiple sclerosis and experimental autoimmune encephalomyelitis. Clin Exp Immunol 2022; 209:140-150. [PMID: 35641229 PMCID: PMC9390842 DOI: 10.1093/cei/uxac017] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 11/14/2022] Open
Abstract
Multiple sclerosis (MS), a white matter demyelinating disease of the central nervous system (CNS), is characterized by neuroinflammatory and neurodegenerative. Experimental autoimmune encephalomyelitis (EAE) is a commonly used animal model for investigating pathogenic mechanisms of MS, representing the destruction of the blood-brain barrier (BBB), the activation of T cells, and the infiltration of myeloid cells. An increasing number of studies have documented that autophagy plays a critical role in the pathogenesis of both MS and EAE. Autophagy maintains CNS homeostasis by degrading the damaged organelles and abnormal proteins. Furthermore, autophagy is involved in inflammatory responses by regulating the activation of immune cells and the secretion of inflammatory factors. However, the specific mechanisms of autophagy involved in MS and EAE are not completely understood. In this review, we will summarize the complex mechanisms of autophagy in MS and EAE, providing potential therapeutic approaches for the management of MS.
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Affiliation(s)
- Donghui Shen
- Department of Neurology, Qingdao Municipal Hospital, Qingdao 266000, Shan Dong Province, China
| | - Kang Liu
- Department of Stomatology, Qingdao Municipal Hospital, Qingdao 266000, Shan Dong Province, China
| | - Hongyan Wang
- Department of Neurology, Qingdao Municipal Hospital, Qingdao 266000, Shan Dong Province, China
| | - Haifeng Wang
- Correspondence: Haifeng Wang, Department of Neurology, Qingdao Municipal Hospital, Qingdao, Shan Dong Province, China.
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Abu-Eid R, Ward FJ. Targeting the PI3K/Akt/mTOR pathway: A therapeutic strategy in COVID-19 patients. Immunol Lett 2021; 240:1-8. [PMID: 34562551 PMCID: PMC8457906 DOI: 10.1016/j.imlet.2021.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/31/2021] [Accepted: 09/15/2021] [Indexed: 12/25/2022]
Abstract
Some COVID-19 patients suffer complications from anti-viral immune responses which can lead to both a dangerous cytokine storm and development of blood-borne factors that render severe thrombotic events more likely. The precise immune response profile is likely, therefore, to determine and predict patient outcomes and also represents a target for intervention. Anti-viral T cell exhaustion in the early stages is associated with disease progression. Dysregulation of T cell functions, which precedes cytokine storm development and neutrophil expansion in alveolar tissues heralds damaging pathology.T cell function, cytokine production and factors that attract neutrophils to the lung can be modified through targeting molecules that can modulate T cell responses. Manipulating T cell responses by targeting the PI3K/Akt/mTOR pathway could provide the means to control the immune response in COVID-19 patients. During the initial anti-viral response, T cell effector function can be enhanced by delaying anti-viral exhaustion through inhibiting PI3K and Akt. Additionally, immune dysregulation can be addressed by enhancing immune suppressor functions by targeting downstream mTOR, an important intracellular modulator of cellular metabolism. Targeting this signalling pathway also has potential to prevent formation of thrombi due to its role in platelet activation. Furthermore, this signalling pathway is essential for SARS-cov-2 virus replication in host cells and its inhibition could, therefore, reduce viral load. The ultimate goal is to identify targets that can quickly control the immune response in COVID-19 patients to improve patient outcome. Targeting different levels of the PI3K/Akt/mTOR signalling pathway could potentially achieve this during each stage of the disease.
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Affiliation(s)
- Rasha Abu-Eid
- Institute of Dentistry, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, Scotland, United Kingdom; Institute of Medical Sciences, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, Scotland, United Kingdom.
| | - Frank James Ward
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, Scotland, United Kingdom.
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10
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Tang Y, Ma T, Jia S, Zhang Q, Liu S, Qi L, Yang L. The Mechanism of Interleukin-35 in Chronic Hepatitis B. Semin Liver Dis 2021; 41:516-524. [PMID: 34233371 DOI: 10.1055/s-0041-1731708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Interleukin-35 (IL-35) is a newly identified inhibitory cytokine. It has recently been found to play an extremely important role in chronic hepatitis B disease, which makes it likely to be a target for new therapies for hepatitis B malady. IL-35 modulates a variety of immune mechanisms to cause persistent viral infections, such as affecting the ratio of helper T cells, reducing the activity of cytotoxic T cells, hindering the antigen presentation capacity for dendritic cells, and increasing the transcription level of hepatitis B virus. On the other hand, IL-35 can control the inflammation caused by hepatitis B liver injury. Therefore, to seek a breakthrough in curing hepatitis B disease, the contradictory part of IL-35 in the occurrence and development of this sickness is worthy of further discussion and research. This article will systematically review the biological effects of IL-35 and the specific mechanisms affecting the disease.
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Affiliation(s)
- Ying Tang
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
| | - Tianyi Ma
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
| | - Shengnan Jia
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
| | - Qian Zhang
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
| | - Siqi Liu
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
| | - Ling Qi
- Department of Core Medical Laboratory, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, China
| | - Lanlan Yang
- Diseases Center, Department of Hepatopancreatobiliary Medicine, The Second Hospital, Jilin University, Changchun, China
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Miao Y, Zheng Y, Geng Y, Yang L, Cao N, Dai Y, Wei Z. The role of GLS1-mediated glutaminolysis/2-HG/H3K4me3 and GSH/ROS signals in Th17 responses counteracted by PPARγ agonists. Theranostics 2021; 11:4531-4548. [PMID: 33754076 PMCID: PMC7977454 DOI: 10.7150/thno.54803] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023] Open
Abstract
Background: Peroxisome proliferator-activated receptor gamma (PPARγ) has the ability to counter Th17 responses, but the full mechanisms remain elusive. Herein, we aimed to elucidate this process in view of cellular metabolism, especially glutaminolysis. Methods: MTT, CCK-8, Annexin V-FITC/PI staining or trypan blue exclusion assays were used to analyze cytotoxicity. Flow cytometry and Q-PCR assays were applied to determine Th17 responses. The detection of metabolite levels using commercial kits and rate-limiting enzyme expression using western blotting assays was performed to illustrate the metabolic activity. ChIP assays were used to examine H3K4me3 modifications. Mouse models of dextran sulfate sodium (DSS)-induced colitis and house dust mite (HDM)/lipopolysaccharide (LPS)-induced asthma were established to confirm the mechanisms studied in vitro. Results: The PPARγ agonists rosiglitazone and pioglitazone blocked glutaminolysis but not glycolysis under Th17-skewing conditions, as indicated by the detection of intracellular lactate and α-KG and the fluorescence ratios of BCECF-AM. The PPARγ agonists prevented the utilization of glutamine and thus directly limited Th17 responses even when Foxp3 was deficient. The mechanisms were ascribed to restricted conversion of glutamine to glutamate by reducing the expression of the rate-limiting enzyme GLS1, which was confirmed by GLS1 overexpression. Replenishment of α-KG and 2-HG but not succinate weakened the effects of PPARγ agonists, and α-KG-promoted Th17 responses were dampened by siIDH1/2. Inhibition of KDM5 but not KDM4/6 restrained the inhibitory effect of PPARγ agonists on IL-17A expression, and the H3K4me3 level in the promoter and CNS2 region of the il-17 gene locus down-regulated by PPARγ agonists was rescued by 2-HG and GLS1 overexpression. However, the limitation of PPARγ agonists on the mRNA expression of RORγt was unable to be stopped by 2-HG but was attributed to GSH/ROS signals subsequent to GLS1. The exact role of PPARγ was proved by GW9662 or PPARγ knockout, and the mechanisms for PPARγ-inhibited Th17 responses were further confirmed by GLS1 overexpression in vivo. Conclusion: PPARγ agonists repressed Th17 responses by counteracting GLS1-mediated glutaminolysis/2-HG/H3K4me3 and GSH/ROS signals, which is beneficial for Th17 cell-related immune dysregulation.
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Balyan R, Gautam N, Gascoigne NR. The Ups and Downs of Metabolism during the Lifespan of a T Cell. Int J Mol Sci 2020; 21:E7972. [PMID: 33120978 PMCID: PMC7663011 DOI: 10.3390/ijms21217972] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/16/2020] [Accepted: 10/24/2020] [Indexed: 02/07/2023] Open
Abstract
Understanding the various mechanisms that govern the development, activation, differentiation, and functions of T cells is crucial as it could provide opportunities for therapeutic interventions to disrupt immune pathogenesis. Immunometabolism is one such area that has garnered significant interest in the recent past as it has become apparent that cellular metabolism is highly dynamic and has a tremendous impact on the ability of T cells to grow, activate, and differentiate. In each phase of the lifespan of a T-cell, cellular metabolism has to be tailored to match the specific functional requirements of that phase. Resting T cells rely on energy-efficient oxidative metabolism but rapidly shift to a highly glycolytic metabolism upon activation in order to meet the bioenergetically demanding process of growth and proliferation. However, upon antigen clearance, T cells return to a more quiescent oxidative metabolism to support T cell memory generation. In addition, each helper T cell subset engages distinct metabolic pathways to support their functional needs. In this review, we provide an overview of the metabolic changes that occur during the lifespan of a T cell and discuss several important studies that provide insights into the regulation of the metabolic landscape of T cells and how they impact T cell development and function.
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Affiliation(s)
| | | | - Nicholas R.J. Gascoigne
- Immunology Programme and Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore 117545, Singapore; (R.B.); (N.G.)
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13
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COVID-19: Proposing a Ketone-Based Metabolic Therapy as a Treatment to Blunt the Cytokine Storm. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:6401341. [PMID: 33014275 PMCID: PMC7519203 DOI: 10.1155/2020/6401341] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/22/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023]
Abstract
Human SARS-CoV-2 infection is characterized by a high mortality rate due to some patients developing a large innate immune response associated with a cytokine storm and acute respiratory distress syndrome (ARDS). This is characterized at the molecular level by decreased energy metabolism, altered redox state, oxidative damage, and cell death. Therapies that increase levels of (R)-beta-hydroxybutyrate (R-BHB), such as the ketogenic diet or consuming exogenous ketones, should restore altered energy metabolism and redox state. R-BHB activates anti-inflammatory GPR109A signaling and inhibits the NLRP3 inflammasome and histone deacetylases, while a ketogenic diet has been shown to protect mice from influenza virus infection through a protective γδ T cell response and by increasing electron transport chain gene expression to restore energy metabolism. During a virus-induced cytokine storm, metabolic flexibility is compromised due to increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) that damage, downregulate, or inactivate many enzymes of central metabolism including the pyruvate dehydrogenase complex (PDC). This leads to an energy and redox crisis that decreases B and T cell proliferation and results in increased cytokine production and cell death. It is hypothesized that a moderately high-fat diet together with exogenous ketone supplementation at the first signs of respiratory distress will increase mitochondrial metabolism by bypassing the block at PDC. R-BHB-mediated restoration of nucleotide coenzyme ratios and redox state should decrease ROS and RNS to blunt the innate immune response and the associated cytokine storm, allowing the proliferation of cells responsible for adaptive immunity. Limitations of the proposed therapy include the following: it is unknown if human immune and lung cell functions are enhanced by ketosis, the risk of ketoacidosis must be assessed prior to initiating treatment, and permissive dietary fat and carbohydrate levels for exogenous ketones to boost immune function are not yet established. The third limitation could be addressed by studies with influenza-infected mice. A clinical study is warranted where COVID-19 patients consume a permissive diet combined with ketone ester to raise blood ketone levels to 1 to 2 mM with measured outcomes of symptom severity, length of infection, and case fatality rate.
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14
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Alvarez F, Al-Aubodah TA, Yang YH, Piccirillo CA. Mechanisms of T REG cell adaptation to inflammation. J Leukoc Biol 2020; 108:559-571. [PMID: 32202345 DOI: 10.1002/jlb.1mr0120-196r] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/19/2020] [Accepted: 02/03/2020] [Indexed: 12/17/2022] Open
Abstract
Inflammation is an important defense mechanism. In this complex and dynamic process, drastic changes in the tissue micro-environment play key roles in dictating the nature of the evolving immune response. However, uncontrolled inflammation is detrimental, leading to unwanted cellular damage, loss of physiological functions, and even death. As such, the immune system possesses tools to limit inflammation while ensuring rapid and effective clearance of the inflammatory trigger. Foxp3+ regulatory T (TREG ) cells, a potently immunosuppressive CD4+ T cell subset, play a crucial role in immune tolerance by controlling the extent of the response to self and non-self Ags, all-the-while promoting a quick return to immune homeostasis. TREG cells adapt to changes in the local micro-environment enabling them to migrate, proliferate, survive, differentiate, and tailor their suppressive ability at inflamed sites. Several inflammation-associated factors can impact TREG cell functional adaptation in situ including locally released alarmins, oxygen availability, tissue acidity and osmolarity and nutrient availability. Here, we review some of these key signals and pathways that control the adaptation of TREG cell function in inflammatory settings.
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Affiliation(s)
- Fernando Alvarez
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.,Program in Infectious Diseases and Immunology in Global Health, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Centre of Excellence in Translational Immunology (CETI), Montréal, Québec, Canada
| | - Tho-Alfakar Al-Aubodah
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.,Program in Infectious Diseases and Immunology in Global Health, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Centre of Excellence in Translational Immunology (CETI), Montréal, Québec, Canada
| | - Yujian H Yang
- Program in Infectious Diseases and Immunology in Global Health, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Centre of Excellence in Translational Immunology (CETI), Montréal, Québec, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Ciriaco A Piccirillo
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.,Program in Infectious Diseases and Immunology in Global Health, Centre for Translational Biology, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.,Centre of Excellence in Translational Immunology (CETI), Montréal, Québec, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada
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