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Anderson S, Grist JT, Lewis A, Tyler DJ. Hyperpolarized 13 C magnetic resonance imaging for noninvasive assessment of tissue inflammation. NMR IN BIOMEDICINE 2021; 34:e4460. [PMID: 33291188 PMCID: PMC7900961 DOI: 10.1002/nbm.4460] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/22/2020] [Accepted: 11/23/2020] [Indexed: 05/03/2023]
Abstract
Inflammation is a central mechanism underlying numerous diseases and incorporates multiple known and potential future therapeutic targets. However, progress in developing novel immunomodulatory therapies has been slowed by a need for improvement in noninvasive biomarkers to accurately monitor the initiation, development and resolution of immune responses as well as their response to therapies. Hyperpolarized magnetic resonance imaging (MRI) is an emerging molecular imaging technique with the potential to assess immune cell responses by exploiting characteristic metabolic reprogramming in activated immune cells to support their function. Using specific metabolic tracers, hyperpolarized MRI can be used to produce detailed images of tissues producing lactate, a key metabolic signature in activated immune cells. This method has the potential to further our understanding of inflammatory processes across different diseases in human subjects as well as in preclinical models. This review discusses the application of hyperpolarized MRI to the imaging of inflammation, as well as the progress made towards the clinical translation of this emerging technique.
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Affiliation(s)
- Stephanie Anderson
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| | - James T. Grist
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
- Division of Cardiovascular Medicine, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Department of Radiology, The Churchill HospitalOxford University Hospitals TrustHeadingtonUK
| | - Andrew Lewis
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
- Division of Cardiovascular Medicine, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Damian J. Tyler
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
- Division of Cardiovascular Medicine, Radcliffe Department of MedicineUniversity of OxfordOxfordUK
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102
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Peng X, He Y, Huang J, Tao Y, Liu S. Metabolism of Dendritic Cells in Tumor Microenvironment: For Immunotherapy. Front Immunol 2021; 12:613492. [PMID: 33732237 PMCID: PMC7959811 DOI: 10.3389/fimmu.2021.613492] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Dendritic cells (DCs) are a type of an antigen-presenting cell which undertake a job on capturing antigens coming from pathogens or tumors and presenting to T cells for immune response. The metabolism of DCs controls its development, polarization, and maturation processes and provides energy support for its functions. However, the immune activity of DCs in tumor microenvironment (TME) is inhibited generally. Abnormal metabolism of tumor cells causes metabolic changes in TME, such as hyperglycolysis, lactate and lipid accumulation, acidification, tryptophan deprivation, which limit the function of DCs and lead to the occurrence of tumor immune escape. Combined metabolic regulation with immunotherapy can strengthen the ability of antigen-presentation and T cell activation of DCs, improve the existing anti-tumor therapy, and overcome the defects of DC-related therapies in the current stage, which has great potential in oncology therapy. Therefore, we reviewed the glucose, lipid, and amino acid metabolism of DCs, as well as the metabolic changes after being affected by TME. Together with the potential metabolic targets of DCs, possible anti-tumor therapeutic pathways were summarized.
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Affiliation(s)
- Xin Peng
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Youe He
- Department of Translational Medicine, Cancer Biological Treatment Center, Xiangya Hospital, Central South University, Changsha, China.,Institute of Medical Sciences, Xiangya Hospital, Central South University, Changsha, China
| | - Jun Huang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Yongguang Tao
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Department of Pathology, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis of Ministry of Health, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, China.,Hunan Key Laboratory of Tumor Models and Individualized Medicine, Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, Changsha, China
| | - Shuang Liu
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Medical Sciences, Xiangya Hospital, Central South University, Changsha, China.,Department of Oncology, Institute of Medical Sciences, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
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103
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Bassaganya-Riera J, Berry EM, Blaak EE, Burlingame B, le Coutre J, van Eden W, El-Sohemy A, German JB, Knorr D, Lacroix C, Muscaritoli M, Nieman DC, Rychlik M, Scholey A, Serafini M. Goals in Nutrition Science 2020-2025. Front Nutr 2021; 7:606378. [PMID: 33665201 PMCID: PMC7923694 DOI: 10.3389/fnut.2020.606378] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/26/2020] [Indexed: 12/12/2022] Open
Abstract
Five years ago, with the editorial board of Frontiers in Nutrition, we took a leap of faith to outline the Goals for Nutrition Science - the way we see it (1). Now, in 2020, we can put ourselves to the test and take a look back. Without a doubt we got it right with several of the key directions. To name a few, Sustainable Development Goals (SDGs) for Food and Nutrition are part of the global public agenda, and the SDGs contribute to the structuring of international science and research. Nutritional Science has become a critical element in strengthening work on the SDGs, and the development of appropriate methodologies is built on the groundwork of acquiring and analyzing big datasets. Investigation of the Human Microbiome is providing novel insight on the interrelationship between nutrition, the immune system and disease. Finally, with an advanced definition of the gut-brain-axis we are getting a glimpse into the potential for Nutrition and Brain Health. Various milestones have been achieved, and any look into the future will have to consider the lessons learned from Covid-19 and the sobering awareness about the frailty of our food systems in ensuring global food security. With a view into the coming 5 years from 2020 to 2025, the editorial board has taken a slightly different approach as compared to the previous Goals article. A mind map has been created to outline the key topics in nutrition science. Not surprisingly, when looking ahead, the majority of scientific investigation required will be in the areas of health and sustainability. Johannes le Coutre, Field Chief Editor, Frontiers in Nutrition.
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Affiliation(s)
- Josep Bassaganya-Riera
- Nutritional Immunology and Molecular Medicine Laboratory (NIMML) Institute, Blacksburg, VA, United States
| | - Elliot M Berry
- Braun School of Public Health, Hebrew University - Hadassah Medical School, Jerusalem, Israel
| | - Ellen E Blaak
- Department of Human Biology, Maastricht University, Maastricht, Netherlands
| | | | - Johannes le Coutre
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Willem van Eden
- Department of Infectious Diseases and Immunology, Utrecht University, Utrecht, Netherlands
| | - Ahmed El-Sohemy
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - J Bruce German
- Department of Food Science and Technology, University of California, Davis, Davis, CA, United States
| | - Dietrich Knorr
- Institute of Food Technology and Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Christophe Lacroix
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Maurizio Muscaritoli
- Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy
| | - David C Nieman
- Human Performance Laboratory, Department of Biology, Appalachian State University, Kannapolis, NC, United States
| | - Michael Rychlik
- Technical University of Munich, Analytical Food Chemistry, Freising, Germany
| | - Andrew Scholey
- Centre for Human Psychopharmacology, Swinburne University, Melbourne, VIC, Australia
| | - Mauro Serafini
- Functional Food and Metabolic Stress Prevention Laboratory, Faculty of Biosciences and Technologies for Agriculture, Food and Environment, University of Teramo, Teramo, Italy
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104
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Braga TT, Foresto-Neto O, Camara NOS. The role of uric acid in inflammasome-mediated kidney injury. Curr Opin Nephrol Hypertens 2021; 29:423-431. [PMID: 32452918 DOI: 10.1097/mnh.0000000000000619] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Uric acid is produced after purine nucleotide degradation, upon xanthine oxidase catalytic action. In the evolutionary process, humans lost uricase, an enzyme that converts uric acid into allantoin, resulting in increased serum uric acid levels that may vary according to dietary ingestion, pathological conditions, and other factors. Despite the controversy over the inflammatory role of uric acid in its soluble form, crystals of uric acid are able to activate the NLRP3 inflammasome in different tissues. Uric acid, therefore, triggers hyperuricemic-related disease such as gout, metabolic syndrome, and kidney injuries. The present review provides an overview on the role of uric acid in the inflammasome-mediated kidney damage. RECENT FINDINGS Hyperuricemia is present in 20-35% of patients with chronic kidney disease. However, whether this increased circulating uric acid is a risk factor or just a biomarker of renal and cardiovascular injuries has become a topic of intense discussion. Despite these conflicting views, several studies support the idea that hyperuricemia is indeed a cause of progression of kidney disease, with a putative role for soluble uric acid in activating renal NLRP3 inflammasome, in reprograming renal and immune cell metabolism and, therefore, in promoting kidney inflammation/injury. SUMMARY Therapies aiming to decrease uric acid levels prevent renal NLRP3 inflammasome activation and exert renoprotective effects in experimental kidney diseases. However, further clinical studies are needed to investigate whether reduced circulating uric acid can also inhibit the inflammasome and be beneficial in human conditions.
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Affiliation(s)
- Tarcio Teodoro Braga
- Department of Basic Pathology, Federal University of Parana, Curitiba, PR.,Carlos Chagas Institute - Fiocruz-Parana, Curitiba
| | - Orestes Foresto-Neto
- Nephrology Division, Federal University of São Paulo.,Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, SP, Brazil
| | - Niels Olsen Saraiva Camara
- Nephrology Division, Federal University of São Paulo.,Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, SP, Brazil
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105
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Yu F, Zhu J, Lei M, Wang C, Xie K, Xu F, Lin S. Exploring the metabolic phenotypes associated with different host inflammation of acute respiratory distress syndrome (ARDS) from lung metabolomics in mice. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e8971. [PMID: 33049802 PMCID: PMC7646044 DOI: 10.1002/rcm.8971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE The aim of this study was to analyze the metabolomics of lung with different host inflammation of acute respiratory distress syndrome (ARDS) for the identification of biomarkers for predicting severity under different inflammatory conditions. METHODS Cecal ligation and puncture (CLP) and lipopolysaccharide (LPS)-intratracheal injection induced acute lung injury (ALI) were used. A mouse model was used to explore lung metabolomic biomarkers in ALI/ARDS. The splenectomy model was used as an auxiliary method to distinguish between hyper- and hypo-inflammatory subtypes. Plasma, lung tissue and bronchoalveolar lavage fluid (BALF) samples were collected from mice after CLP/LPS. The severity of lung injury was evaluated. Expression of tumor necrosis factor-α (TNF-α) in mice serum and lung was tested by enzyme-linked immunosorbent assay (ELISA) and polymer chain reaction (PCR). Polymorphonuclear cells in BALF were counted. The lung metabolites were detected by gas chromatography/mass spectrometry (GC/MS), and the metabolic pathways predicted using the KEGG database. RESULTS The LPS/CLP-Splen group had more severe lung injury than the corresponding ALI group; that in the CLP-Splen group was more serious than in the LPS-Splen group. TNF-α expression was significantly elevated in the serum and lung tissue after LPS or CLP, and higher in the LPS/CLP-Splen group than in the corresponding ALI group. The level of TNF-α in the CLP-Splen group was elevated significantly over that in the LPS-Splen group. Both these groups also showed significant neutrophil exudation within the lungs. During differential inflammation, more differential metabolites were detected in the lungs of the CLP group ALI mice than in the LPS group. A total of 41 compounds were detected in the lungs of the CLP and CLP-Splen groups. Contrastingly, eight compounds were detected in the lungs of the LPS and LPS-Splen groups. The LPS-Splen and CLP-Splen groups had significant neutrophil exudation in the lung. Random forest analysis of lung-targeted metabolomics data indicated 4-hydroxyphenylacetic acid, 1-aminocyclopentanecarboxylic acid (ACPC), cis-aconitic acid, and hydroxybenzoic acid as strong predictors of the hyper-inflammatory subgroup in the CLP group. Furthermore, with splenectomy, 13 differential metabolic pathways between the CLP and LPS groups were revealed. CONCLUSIONS Hyper-inflammatory subgroups of ARDS have a greater inflammatory response and a more active lung metabolism. Combined with the host inflammation background, biomarkers from metabolomics could help evaluate the response severity of ARDS.
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Affiliation(s)
- Feng Yu
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
- Department of Critical Care MedicineChangshou People's HospitalChongqing401220China
| | - Jing Zhu
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
| | - Ming Lei
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
- Department of Critical Care MedicineThe Seventh Affiliated Hospital, Sun Yat‐sen UniversityShenzhen518000China
| | - Chuan‐jiang Wang
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
| | - Ke Xie
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
| | - Fang Xu
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
| | - Shi‐hui Lin
- Department of Critical Care MedicineThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China
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106
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Immuno-Metabolism: The Role of Cancer Niche in Immune Checkpoint Inhibitor Resistance. Int J Mol Sci 2021; 22:ijms22031258. [PMID: 33514004 PMCID: PMC7865434 DOI: 10.3390/ijms22031258] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
The use of immune checkpoint inhibitors (ICI) in treating cancer has revolutionized the approach to eradicate cancer cells by reactivating immune responses. However, only a subset of patients benefits from this treatment; the majority remains unresponsive or develops resistance to ICI therapy. Increasing evidence suggests that metabolic machinery in the tumor microenvironment (TME) plays a role in the development of ICI resistance. Within the TME, nutrients and oxygen are scarce, forcing immune cells to undergo metabolic reprogramming to adapt to harsh conditions. Cancer-induced metabolic deregulation in immune cells can attenuate their anti-cancer properties, but can also increase their immunosuppressive properties. Therefore, targeting metabolic pathways of immune cells in the TME may strengthen the efficacy of ICIs and prevent ICI resistance. In this review, we discuss the interactions of immune cells and metabolic alterations in the TME. We also discuss current therapies targeting cellular metabolism in combination with ICIs for the treatment of cancer, and provide possible mechanisms behind the cellular metabolic rewiring that may improve clinical outcomes.
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107
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Sun Y, Lu Y, Saredy J, Wang X, Drummer Iv C, Shao Y, Saaoud F, Xu K, Liu M, Yang WY, Jiang X, Wang H, Yang X. ROS systems are a new integrated network for sensing homeostasis and alarming stresses in organelle metabolic processes. Redox Biol 2020; 37:101696. [PMID: 32950427 PMCID: PMC7767745 DOI: 10.1016/j.redox.2020.101696] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are critical for the progression of cardiovascular diseases, inflammations and tumors. However, the mechanisms of how ROS sense metabolic stress, regulate metabolic pathways and initiate proliferation, inflammation and cell death responses remain poorly characterized. In this analytic review, we concluded that: 1) Based on different features and functions, eleven types of ROS can be classified into seven functional groups: metabolic stress-sensing, chemical connecting, organelle communication, stress branch-out, inflammasome-activating, dual functions and triple functions ROS. 2) Among the ROS generation systems, mitochondria consume the most amount of oxygen; and nine types of ROS are generated; thus, mitochondrial ROS systems serve as the central hub for connecting ROS with inflammasome activation, trained immunity and immunometabolic pathways. 3) Increased nuclear ROS production significantly promotes cell death in comparison to that in other organelles. Nuclear ROS systems serve as a convergent hub and decision-makers to connect unbearable and alarming metabolic stresses to inflammation and cell death. 4) Balanced ROS levels indicate physiological homeostasis of various metabolic processes in subcellular organelles and cytosol, while imbalanced ROS levels present alarms for pathological organelle stresses in metabolic processes. Based on these analyses, we propose a working model that ROS systems are a new integrated network for sensing homeostasis and alarming stress in metabolic processes in various subcellular organelles. Our model provides novel insights on the roles of the ROS systems in bridging metabolic stress to inflammation, cell death and tumorigenesis; and provide novel therapeutic targets for treating those diseases. (Word count: 246).
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Affiliation(s)
- Yu Sun
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Yifan Lu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Jason Saredy
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xianwei Wang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Charles Drummer Iv
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Ying Shao
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Fatma Saaoud
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Keman Xu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Ming Liu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - William Y Yang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xiaohua Jiang
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA; Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Hong Wang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xiaofeng Yang
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA; Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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108
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Osei-Bordom D, Bozward AG, Oo YH. The hepatic microenvironment and regulatory T cells. Cell Immunol 2020; 357:104195. [PMID: 32861844 DOI: 10.1016/j.cellimm.2020.104195] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 12/16/2022]
Abstract
The human liver is regarded as a lymphoid organ that contributes to both local and systemic immune response. Intrahepatic immune cells including regulatory T cells (Tregs) reside in the hepatic microenvironment which is enriched with proinflammatory cytokines, chemokines and metabolites. In addition, the hepatic microenvironment has the unique ability to establish and maintain immune tolerance despite the continuous influx of the gut derived microbial products via the portal vein. Regulatory T cells play a crucial role in maintaining the hepatic tolerogenic state; however, the phenotypic stability, function and survival of Tregs in the inflamed liver microenvironment is still poorly understood. Despite this, Tregs immunotherapy remains as an appealing therapeutic option in autoimmune and immune mediated liver diseases. In order to advance cell therapy, it is important for us to further our understanding of the hepatic microenvironment, with the aim of developing ways to modify the hostile, inflamed environment to one which is more favourable. By doing so, T cell stability and function would be enhanced, resulting in improved clinical outcomes.
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Affiliation(s)
- Daniel Osei-Bordom
- Centre for Liver Research and NIHR BRC, Institute of Immunology and Immunotherapy, University of Birmingham, United Kingdom; European Reference Network Centre: Rare Liver, United Kingdom; Queen Elizabeth Hospital, University Hospital of Birmingham NHS Foundation Trust, United Kingdom
| | - Amber G Bozward
- Centre for Liver Research and NIHR BRC, Institute of Immunology and Immunotherapy, University of Birmingham, United Kingdom; European Reference Network Centre: Rare Liver, United Kingdom
| | - Ye Htun Oo
- Centre for Liver Research and NIHR BRC, Institute of Immunology and Immunotherapy, University of Birmingham, United Kingdom; European Reference Network Centre: Rare Liver, United Kingdom; Queen Elizabeth Hospital, University Hospital of Birmingham NHS Foundation Trust, United Kingdom.
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109
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Mitochondrial function in immune cells in health and disease. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165845. [PMID: 32473386 DOI: 10.1016/j.bbadis.2020.165845] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 02/06/2023]
Abstract
One of the main functions of mitochondria is production of ATP for cellular energy needs, however, it becomes more recognized that mitochondria are involved in differentiation and activation processes of immune cells. Upon activation, immune cells have a high need for energy. Immune cells have different strategies to generate this energy. In pro-inflammatory cells, such as activated monocytes and activated T and B cells, the energy is generated by increasing glycolysis, while in regulatory cells, such as regulatory T cells or M2 macrophages, energy is generated by increasing mitochondrial function and beta-oxidation. Except for being important for energy supply during activation, mitochondria also induce immune responses. During an infection, they release mitochondrial danger associated molecules (DAMPs) that resemble structures of bacterial derived pathogen associated molecular patterns (PAMPs). Such mitochondrial DAMPS are for instance mitochondrial DNA with hypomethylated CpG motifs or a specific lipid that is only present in prokaryotic bacteria and mitochondria, i.e. cardiolipin. Via release of such DAMPs, mitochondria guide the immune response towards an inflammatory response against pathogens. This is an important mechanism in early detection of an infection and in stimulating and sustaining immune responses to fight infections. However, mitochondrial DAMPs may also have a negative impact. If mitochondrial DAMPs are released by damaged cells, without the presence of an infection, such as after a trauma, mitochondrial DAMPs may induce an undesired inflammatory response, resulting in tissue damage and organ dysfunction. Thus, immune cells have developed mechanisms to prevent such undesired immune activation by mitochondrial components. In the present narrative review, we will describe the current view of mitochondria in regulation of immune responses. We will also discuss the current knowledge on disturbed mitochondrial function in immune cells in various immunological diseases.
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110
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Beneficial and Detrimental Effects of Regulatory T Cells in Neurotropic Virus Infections. Int J Mol Sci 2020; 21:ijms21051705. [PMID: 32131483 PMCID: PMC7084400 DOI: 10.3390/ijms21051705] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/07/2023] Open
Abstract
Neurotropic viruses infect the central nervous system (CNS) and cause acute or chronic neurologic disabilities. Regulatory T cells (Treg) play a critical role for immune homeostasis, but may inhibit pathogen-specific immunity in infectious disorders. The present review summarizes the current knowledge about Treg in human CNS infections and their animal models. Besides dampening pathogen-induced immunopathology, Treg have the ability to facilitate protective responses by supporting effector T cell trafficking to the infection site and the development of resident memory T cells. Moreover, Treg can reduce virus replication by inducing apoptosis of infected macrophages and attenuate neurotoxic astrogliosis and pro-inflammatory microglial responses. By contrast, detrimental effects of Treg are caused by suppression of antiviral immunity, allowing for virus persistence and latency. Opposing disease outcomes following Treg manipulation in different models might be attributed to differences in technique and timing of intervention, infection route, genetic background, and the host’s age. In addition, mouse models of virus-induced demyelination revealed that Treg are able to reduce autoimmunity and immune-mediated CNS damage in a disease phase-dependent manner. Understanding the unique properties of Treg and their complex interplay with effector cells represents a prerequisite for the development of new therapeutic approaches in neurotropic virus infections.
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