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Ybarra TK, Bishop GA. TRAF3 regulation of proximal TLR signaling in B cells. J Leukoc Biol 2024; 116:210-223. [PMID: 38489541 PMCID: PMC11271984 DOI: 10.1093/jleuko/qiae038] [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: 12/07/2023] [Revised: 01/24/2024] [Accepted: 02/09/2024] [Indexed: 03/17/2024] Open
Abstract
Toll-like receptors are pattern recognition receptors that bridge the innate and adaptive immune responses and are critical for host defense. Most studies of Toll-like receptors have focused upon their roles in myeloid cells. B lymphocytes express most Toll-like receptors and are responsive to Toll-like receptor ligands, yet Toll-like receptor-mediated signaling in B cells is relatively understudied. This is an important knowledge gap, as Toll-like receptor functions can be cell type specific. In striking contrast to myeloid cells, TRAF3 inhibits TLR-mediated functions in B cells. TRAF3-deficient B cells display enhanced IRF3 and NFκB activation, cytokine production, immunoglobulin isotype switching, and antibody production in response to Toll-like receptors 3, 4, 7, and 9. Here, we address the question of how TRAF3 impacts initial B-cell Toll-like receptor signals to regulate downstream activation. We found that TRAF3 in B cells associated with proximal Toll-like receptor 4 and 7 signaling proteins, including MyD88, TRAF6, and the tyrosine kinase Syk. In the absence of TRAF3, TRAF6 showed a greater association with several Toll-like receptor signaling proteins, suggesting that TRAF3 may inhibit TRAF6 access to Toll-like receptor signaling complexes and thus early Toll-like receptor signaling. In addition, our results highlight a key role for Syk in Toll-like receptor signaling in B cells. In the absence of TRAF3, Syk activation was enhanced in response to ligands for Toll-like receptors 4 and 7, and Syk inhibition reduced downstream Toll-like receptor-mediated NFκB activation and proinflammatory cytokine production. This study reveals multiple mechanisms by which TRAF3 serves as a key negative regulator of early Toll-like receptor signaling events in B cells.
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Affiliation(s)
- Tiffany K Ybarra
- Interdisciplinary Graduate Program in Immunology, University of Iowa, 285 Newton Road, Iowa City, IA 52242, United States
- Departments of Microbiology and Immunology, University of Iowa, 285 Newton Road, Iowa City, IA 52242, United States
| | - Gail A Bishop
- Interdisciplinary Graduate Program in Immunology, University of Iowa, 285 Newton Road, Iowa City, IA 52242, United States
- Departments of Microbiology and Immunology, University of Iowa, 285 Newton Road, Iowa City, IA 52242, United States
- VA Medical Center, University of Iowa, 285 Newton Road, Iowa City, IA 52242, United States
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2
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Baig MS, Barmpoutsi S, Bharti S, Weigert A, Hirani N, Atre R, Khabiya R, Sharma R, Sarup S, Savai R. Adaptor molecules mediate negative regulation of macrophage inflammatory pathways: a closer look. Front Immunol 2024; 15:1355012. [PMID: 38482001 PMCID: PMC10933033 DOI: 10.3389/fimmu.2024.1355012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/22/2024] [Indexed: 04/13/2024] Open
Abstract
Macrophages play a central role in initiating, maintaining, and terminating inflammation. For that, macrophages respond to various external stimuli in changing environments through signaling pathways that are tightly regulated and interconnected. This process involves, among others, autoregulatory loops that activate and deactivate macrophages through various cytokines, stimulants, and other chemical mediators. Adaptor proteins play an indispensable role in facilitating various inflammatory signals. These proteins are dynamic and flexible modulators of immune cell signaling and act as molecular bridges between cell surface receptors and intracellular effector molecules. They are involved in regulating physiological inflammation and also contribute significantly to the development of chronic inflammatory processes. This is at least partly due to their involvement in the activation and deactivation of macrophages, leading to changes in the macrophages' activation/phenotype. This review provides a comprehensive overview of the 20 adaptor molecules and proteins that act as negative regulators of inflammation in macrophages and effectively suppress inflammatory signaling pathways. We emphasize the functional role of adaptors in signal transduction in macrophages and their influence on the phenotypic transition of macrophages from pro-inflammatory M1-like states to anti-inflammatory M2-like phenotypes. This endeavor mainly aims at highlighting and orchestrating the intricate dynamics of adaptor molecules by elucidating the associated key roles along with respective domains and opening avenues for therapeutic and investigative purposes in clinical practice.
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Affiliation(s)
- Mirza S. Baig
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Spyridoula Barmpoutsi
- Lung Microenvironmental Niche in Cancerogenesis, Institute for Lung Health (ILH), Justus Liebig University, Giessen, Germany
- Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research (DZL), Member of the Cardio-Pulmonary Institute (CPI), Bad Nauheim, Germany
| | - Shreya Bharti
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Andreas Weigert
- Institute of Biochemistry I, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany
- Frankfurt Cancer Institute (FCI), Goethe University Frankfurt, Frankfurt, Germany
| | - Nik Hirani
- MRC Centre for Inflammation Research, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Rajat Atre
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Rakhi Khabiya
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Rahul Sharma
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Shivmuni Sarup
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Rajkumar Savai
- Lung Microenvironmental Niche in Cancerogenesis, Institute for Lung Health (ILH), Justus Liebig University, Giessen, Germany
- Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research (DZL), Member of the Cardio-Pulmonary Institute (CPI), Bad Nauheim, Germany
- Frankfurt Cancer Institute (FCI), Goethe University Frankfurt, Frankfurt, Germany
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3
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Wu Z, Yang S, Fang X, Shu Q, Chen Q. Function and mechanism of TREM2 in bacterial infection. PLoS Pathog 2024; 20:e1011895. [PMID: 38236825 PMCID: PMC10796033 DOI: 10.1371/journal.ppat.1011895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2024] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2), which is a lipid sensing and phagocytosis receptor, plays a key role in immunity and inflammation in response to pathogens. Here, we review the function and signaling of TREM2 in microbial binding, engulfment and removal, and describe TREM2-mediated inhibition of inflammation by negatively regulating the Toll-like receptor (TLR) response. We further illustrate the role of TREM2 in restoring organ homeostasis in sepsis and soluble TREM2 (sTREM2) as a diagnostic marker for sepsis-associated encephalopathy (SAE). Finally, we discuss the prospect of TREM2 as an interesting therapeutic target for sepsis.
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Affiliation(s)
- Zehua Wu
- Department of the Clinical Research Center, Children’s Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
| | - Shiyue Yang
- Department of Anesthesiology, First Affiliated Hospital of Soochow University, Soochow, People’s Republic of China
| | - Xiangming Fang
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
| | - Qiang Shu
- Department of the Clinical Research Center, Children’s Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
- Key Laboratory of Diagnosis and Treatment of Neonatal Diseases of Zhejiang Province, Hangzhou, People’s Republic of China
| | - Qixing Chen
- Department of the Clinical Research Center, Children’s Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
- Key Laboratory of Diagnosis and Treatment of Neonatal Diseases of Zhejiang Province, Hangzhou, People’s Republic of China
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4
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Miyake K, Shibata T, Fukui R, Murakami Y, Sato R, Hiranuma R. Endosomal Toll-Like Receptors as Therapeutic Targets for Autoimmune Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1444:97-108. [PMID: 38467975 DOI: 10.1007/978-981-99-9781-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Nucleic acid (NA)-sensing Toll-like receptors (TLRs) reside in the endosomal compartment of innate immune cells, such as macrophages and dendritic cells. NAs transported to the endosomal compartment are degraded by DNases and RNases. Degradation products, including single-stranded DNA, oligoRNA, and nucleosides, are recognized by TLR7, TLR8, and TLR9 to drive the defense responses against pathogens. NA degradation influences endosomal TLR responses by generating and degrading TLR ligands. TLR ligand accumulation because of impaired NA degradation causes constitutive TLR activation, leading to autoinflammatory and autoimmune diseases. Furthermore, some genes associated with these diseases promote endosomal TLR responses. Therefore, endosomal TLRs are promising therapeutic targets for TLR-mediated inflammatory diseases, and novel drugs targeting TLRs are being developed.
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Affiliation(s)
- Kensuke Miyake
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
| | - Takuma Shibata
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Ryutaro Fukui
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Yusuke Murakami
- Faculty of Pharmacy, Department of Pharmaceutical Sciences and Research Institute of Pharmaceutical Sciences, Musashino University, Tokyo, Japan
| | - Ryota Sato
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Ryosuke Hiranuma
- Division of Innate Immunity, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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5
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Chen H, Fan L, Guo Q, Wong MY, Yu F, Foxe N, Wang W, Nessim A, Carling G, Liu B, Lopez-Lee C, Huang Y, Amin S, Patel T, Mok SA, Song WM, Zhang B, Ma Q, Fu H, Gan L, Luo W. DAP12 deficiency alters microglia-oligodendrocyte communication and enhances resilience against tau toxicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.26.563970. [PMID: 37961594 PMCID: PMC10634844 DOI: 10.1101/2023.10.26.563970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Pathogenic tau accumulation fuels neurodegeneration in Alzheimer's disease (AD). Enhancing aging brain's resilience to tau pathology would lead to novel therapeutic strategies. DAP12 (DNAX-activation protein 12) is critically involved in microglial immune responses. Previous studies have showed that mice lacking DAP12 in tauopathy mice exhibit higher tau pathology but are protected from tau-induced cognitive deficits. However, the exact mechanism remains elusive. Our current study uncovers a novel resilience mechanism via microglial interaction with oligodendrocytes. Despite higher tau inclusions, Dap12 deletion curbs tau-induced brain inflammation and ameliorates myelin and synapse loss. Specifically, removal of Dap12 abolished tau-induced disease-associated clusters in microglia (MG) and intermediate oligodendrocytes (iOli), which are spatially correlated with tau pathology in AD brains. Our study highlights the critical role of interactions between microglia and oligodendrocytes in tau toxicity and DAP12 signaling as a promising target for enhancing resilience in AD.
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Affiliation(s)
- Hao Chen
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Li Fan
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Qi Guo
- Department of Biomedical Informatics, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Man Ying Wong
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Fangmin Yu
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Nessa Foxe
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | | | - Aviram Nessim
- The State University of New York at Stony Brook, Long Island, New York, USA
| | - Gillian Carling
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Bangyan Liu
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Chloe Lopez-Lee
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yige Huang
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Sadaf Amin
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Tark Patel
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB Canada
| | - Sue-Ann Mok
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB Canada
| | - Won-min Song
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Qin Ma
- Department of Biomedical Informatics, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Hongjun Fu
- Department of Neuroscience, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Li Gan
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Millburn High School, New Jersey, NJ, USA
| | - Wenjie Luo
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
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6
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Chen H, Fan L, Guo Q, Wong MY, Yu F, Foxe N, Wang W, Nessim A, Carling G, Liu B, Lopez-Lee C, Huang Y, Amin S, Mok SA, Song WM, Zhang B, Ma Q, Fu H, Gan L, Luo W. DAP12 deficiency alters microglia-oligodendrocyte communication and enhances resilience against tau toxicity. RESEARCH SQUARE 2023:rs.3.rs-3454358. [PMID: 37961627 PMCID: PMC10635319 DOI: 10.21203/rs.3.rs-3454358/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Pathogenic tau accumulation fuels neurodegeneration in Alzheimer's disease (AD). Enhancing aging brain's resilience to tau pathology would lead to novel therapeutic strategies. DAP12 (DNAX-activation protein 12) is critically involved in microglial immune responses. Previous studies have showed that mice lacking DAP12 in tauopathy mice exhibit higher tau pathology but are protected from tau-induced cognitive deficits. However, the exact mechanism remains elusive. Our current study uncovers a novel resilience mechanism via microglial interaction with oligodendrocytes. Despite higher tau inclusions, Dap12 deletion curbs tau-induced brain inflammation and ameliorates myelin and synapse loss. Specifically, removal of Dap12 abolished tau-induced disease-associated clusters in microglia (MG) and intermediate oligodendrocytes (iOli), which are spatially correlated with tau pathology in AD brains. Our study highlights the critical role of interactions between microglia and oligodendrocytes in tau toxicity and DAP12 signaling as a promising target for enhancing resilience in AD.
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Affiliation(s)
- Hao Chen
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Li Fan
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Qi Guo
- Department of Biomedical Informatics, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Man Ying Wong
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Fangmin Yu
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Nessa Foxe
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | | | - Aviram Nessim
- The State University of New York at Stony Brook, Long Island, New York, USA
| | - Gillian Carling
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Bangyan Liu
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Chloe Lopez-Lee
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yige Huang
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Program of Neuroscience, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Sadaf Amin
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Sue-Ann Mok
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB Canada
| | - Won-min Song
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Qin Ma
- Department of Biomedical Informatics, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Hongjun Fu
- Department of Neuroscience, College of Medicine, Ohio State University, Columbus, OH 43210 USA
| | - Li Gan
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Millburn High School, New Jersey, NJ, USA
| | - Wenjie Luo
- Helen and Robert Appel Alzheimer Disease Research Institute, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
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Abstract
Triggering receptors expressed on myeloid cells (TREMs) encompass a family of cell-surface receptors chiefly expressed by granulocytes, monocytes and tissue macrophages. These receptors have been implicated in inflammation, neurodegenerative diseases, bone remodelling, metabolic syndrome, atherosclerosis and cancer. Here, I review the structure, ligands, signalling modes and functions of TREMs in humans and mice and discuss the challenges that remain in understanding TREM biology.
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Affiliation(s)
- Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA.
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8
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Furuya H, Nguyen CT, Gu R, Hsieh SL, Maverakis E, Adamopoulos IE. Interleukin-23 Regulates Inflammatory Osteoclastogenesis via Activation of CLEC5A(+) Osteoclast Precursors. Arthritis Rheumatol 2023; 75:1477-1489. [PMID: 36787107 PMCID: PMC10423744 DOI: 10.1002/art.42478] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/12/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
OBJECTIVE To investigate the role of interleukin-23 (IL-23) in pathologic bone remodeling in inflammatory arthritis. METHODS In this study we investigated the role of IL-23 in osteoclast differentiation and activation using in vivo gene transfer techniques in wild-type and myeloid DNAX-activation protein 12-associating lectin-1 (MDL-1)-deficient mice, and by performing in vitro and in vivo osteoclastogenesis assays using spectral flow cytometry, micro-computed tomography analysis, Western blotting, and immunoprecipitation. RESULTS Herein, we show that IL-23 induces the expansion of a myeloid osteoclast precursor population and supports osteoclastogenesis and bone resorption in inflammatory arthritis. Genetic ablation of C-type lectin domain family member 5A, also known as MDL-1, prevents the induction of osteoclast precursors by IL-23 that is associated with bone destruction, as commonly observed in inflammatory arthritis. Moreover, osteoclasts derived from the bone marrow of MDL-1-deficient mice showed impaired osteoclastogenesis, and MDL-1-/- mice had increased bone mineral density. CONCLUSION Our data show that IL-23 signaling regulates the availability of osteoclast precursors in inflammatory arthritis that could be effectively targeted for the treatment of inflammatory bone loss in inflammatory arthritis.
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Affiliation(s)
- Hiroki Furuya
- Department of Rheumatology, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Cuong Thach Nguyen
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis
| | - Ran Gu
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, Taiwan
| | - Emanual Maverakis
- Department of Dermatology, University of California, Davis, Sacramento, CA, USA
| | - Iannis E Adamopoulos
- Department of Rheumatology, Beth Israel Deaconess Medical Center, Harvard Medical School
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis
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9
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Wu K, Liu YY, Shao S, Song W, Chen XH, Dong YT, Zhang YM. The microglial innate immune receptors TREM-1 and TREM-2 in the anterior cingulate cortex (ACC) drive visceral hypersensitivity and depressive-like behaviors following DSS-induced colitis. Brain Behav Immun 2023:S0889-1591(23)00141-1. [PMID: 37286175 DOI: 10.1016/j.bbi.2023.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/15/2023] [Accepted: 06/03/2023] [Indexed: 06/09/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a chronic condition with a high recurrence rate. To date, the clinical treatment of IBD mainly focuses on inflammation and gastrointestinal symptoms while ignoring the accompanying visceral pain, anxiety, depression, and other emotional symptoms. Evidence is accumulating that bi-directional communication between the gut and the brain is indispensable in the pathophysiology of IBD and its comorbidities. Increasing efforts have been focused on elucidating the central immune mechanisms in visceral hypersensitivity and depression following colitis. The triggering receptors expressed on myeloid cells-1/2 (TREM-1/2) are newly identified receptors that can be expressed on microglia. In particular, TREM-1 acts as an immune and inflammatory response amplifier, while TREM-2 may function as a molecule with a putative antagonist role to TREM-1. In the present study, using the dextran sulfate sodium (DSS)-induced colitis model, we found that peripheral inflammation induced microglial and glutamatergic neuronal activation in the anterior cingulate cortex (ACC). Microglial ablation mitigated visceral hypersensitivity in the inflammation phase rather than in the remission phase, subsequently preventing the emergence of depressive-like behaviors in the remission phase. Moreover, a further mechanistic study revealed that overexpression of TREM-1 and TREM-2 remarkably aggravated DSS-induced neuropathology. The improved outcome was achieved by modifying the balance of TREM-1 and TREM-2 via genetic and pharmacological means. Specifically, a deficiency of TREM-1 attenuated visceral hyperpathia in the inflammatory phase, and a TREM-2 deficiency improved depression-like symptoms in the remission phase. Taken together, our findings provide insights into mechanism-based therapy for inflammatory disorders and establish that microglial innate immune receptors TREM-1 and TREM-2 may represent a therapeutic target for the treatment of pain and psychological comorbidities associated with chronic inflammatory diseases by modulating neuroinflammatory responses.
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Affiliation(s)
- Ke Wu
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Yue-Ying Liu
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Shuai Shao
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Wei Song
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Xing-Han Chen
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Yu-Ting Dong
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China
| | - Yong-Mei Zhang
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.
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10
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Jiao P, Wang S, Fan W, Zhang H, Yin H, Shang Y, Zhu H, Liu W, Hu R, Sun L. Recombinant porcine interferon cocktail delays the onset and lessens the severity of African swine fever. Antiviral Res 2023; 215:105644. [PMID: 37244381 DOI: 10.1016/j.antiviral.2023.105644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/01/2023] [Accepted: 05/25/2023] [Indexed: 05/29/2023]
Abstract
African swine fever (ASF) is a highly contagious and deadly disease that affects domestic and wild pigs. No commercial vaccine or antiviral is currently available against ASF. The control of ASF primarily relies on implementing effective biosecurity measures during the breeding process. Here, we evaluated the preventive and therapeutic potential of the interferon (IFN) cocktail (a mixture of recombinant porcine IFN α and γ) on ASF. The IFN cocktail treatment delayed the onset of ASF symptoms and ASF virus (ASFV) replication for approximately one week. However, IFN cocktail treatment could not prevent the death of the pigs. Further analysis showed that IFN cocktail treatment increased the expression of multiple IFN-stimulated genes (ISGs) in porcine peripheral blood mononuclear cells in vivo and in vitro. Additionally, IFN cocktail modulated the expression of pro- and anti-inflammatory cytokines and reduced tissue injury in the ASFV-infected pigs. Collectively, the results suggest that the IFN cocktail restricts the progression of acute ASF by inducing high levels of ISGs, contributing to the pre-establishment of antiviral status, and modulating the balance of pro- and anti-inflammatory mediators to lessen cytokine storm-mediated tissue damage.
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Affiliation(s)
- Pengtao Jiao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuchao Wang
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun, 130000, China
| | - Wenhui Fan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - He Zhang
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Guangdong, China
| | - Hongyan Yin
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Yingli Shang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Hongfei Zhu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Wenjun Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; Institute of Infectious Diseases, Shenzhen Bay Laboratory, Guangdong, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rongliang Hu
- Institute of Military Veterinary Medicine, Academy of Military Medical Science, Changchun, 130000, China
| | - Lei Sun
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Siddiqui SS. Non-canonical roles of Siglecs: Beyond sialic acid-binding and immune cell modulation. Mol Aspects Med 2023; 90:101145. [PMID: 36153172 DOI: 10.1016/j.mam.2022.101145] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/11/2022] [Accepted: 09/13/2022] [Indexed: 02/08/2023]
Abstract
Siglecs (Sialic acid-binding immunoglobulin-type lectins) are I-type lectins that bind with sialic acid ligands (Sia). Most are expressed on the surface of leukocytes and are involved in immune regulation and possess immune tyrosine-based inhibitory motif (ITIM) in the intracellular domain, thus leading to inhibition of the immune response. This signaling is instrumental in maintaining quiescence under physiological conditions and acts as a brake for inflammatory cascades. By contrast, activating Siglecs carry positively charged residues in the transmembrane domain and interact with immune tyrosine-based activating motif (ITAM)-containing proteins, a DNAX-activating protein of 10-12 kDa (DAP10/12), to activate immune cells. There are various characteristics of Siglecs that do not fit within the classification of Siglec receptors as being either inhibitory or activating in nature. This review focuses on elucidating the non-canonical functions and interactions of Siglec receptors, which include Sia-independent interactions such as protein-protein interactions and interactions with lipids or other sugars. This review also summarizes Siglec expression and function on non-immune cells, and non-classical signaling of the receptor. Thus, this review will be beneficial to researchers interested in the field of Siglecs and sialic acid biology.
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Affiliation(s)
- Shoib Sarwar Siddiqui
- School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfield, AL10 9AB, United Kingdom.
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12
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Basha SKC, Ramaiah MJ, Kosagisharaf JR. Untangling the Role of TREM2 in Conjugation with Microglia in Neuronal Dysfunction: A Hypothesis on a Novel Pathway in the Pathophysiology of Alzheimer's Disease. J Alzheimers Dis 2023; 94:S319-S333. [PMID: 36683512 PMCID: PMC10473115 DOI: 10.3233/jad-221070] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2022] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder involving heterogenous pathophysiological characteristics, which has become a challenge to therapeutics. The major pathophysiology of AD comprises amyloid-β (Aβ), tau, oxidative stress, and apoptosis. Recent studies indicate the significance of Triggering receptor expressed on myeloid cells 2 (TREM2) and its mutant variants in AD. TREM2 are the transmembrane receptors of microglial cells that performs a broad range of physiological cell processes. Phagocytosis of Aβ is one of the physiological roles of TREM2, which plays a pivotal role in AD progression. R47H, a mutant variant of TREM2, increases the risk of AD by impairing TREM2-Aβ binding. Inconclusive evidence regarding the TREM2 signaling cascade mechanism of Aβ phagocytosis motivates the current review to propose a new hypothesis. The review systematically assesses the cross talk between TREM2 and other AD pathological domains and the influence of TREM2 on amyloid and tau seeding. Disease associated microglia (DAM), a novel state of microglia with unique transcriptional and functional signatures reported in neurodegenerative conditions, also depend on the TREM2 pathway for its differentiation. DAM is suggested to have a neuroprotective role. We hypothesize that TREM2, along with its signaling adaptors and endogenous proteins, play a key role in ameliorating Aβ clearance. We indicate that TREM2 has the potential to ameliorate the Aβ burden, though with differential clearance ability and may act as a potential therapeutic target.
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Affiliation(s)
- SK Chand Basha
- Department of Bio-Technology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, AP, India
| | - Mekala Janaki Ramaiah
- Department of Bio-Technology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, AP, India
| | - Jagannatha Rao Kosagisharaf
- Department of Bio-Technology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, AP, India
- National Science System (SENACYT), INDICASAT – AIP, Panama
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13
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Heinz R, Schneider UC. TLR4-Pathway-Associated Biomarkers in Subarachnoid Hemorrhage (SAH): Potential Targets for Future Anti-Inflammatory Therapies. Int J Mol Sci 2022; 23:ijms232012618. [PMID: 36293468 PMCID: PMC9603851 DOI: 10.3390/ijms232012618] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/20/2022] Open
Abstract
Subarachnoid hemorrhage is associated with severe neurological deficits for survivors. Among survivors of the initial bleeding, secondary brain injury leads to additional brain damage. Apart from cerebral vasospasm, secondary brain injury mainly results from cerebral inflammation taking place in the brain parenchyma after bleeding. The brain’s innate immune system is activated, which leads to disturbances in brain homeostasis, cleavage of inflammatory cytokines and, subsequently, neuronal cell death. The toll-like receptor (TLR)4 signaling pathway has been found to play an essential role in the pathophysiology of acute brain injuries such as subarachnoid hemorrhage (SAH). TLR4 is expressed on the cell surface of microglia, which are key players in the cellular immune responses of the brain. The participants in the signaling pathway, such as TLR4-pathway-like ligands, the receptor itself, and inflammatory cytokines, can act as biomarkers, serving as clues regarding the inflammatory status after SAH. Moreover, protein complexes such as the NLRP3 inflammasome or receptors such as TREM1 frame the TLR4 pathway and are indicative of inflammation. In this review, we focus on the activity of the TLR4 pathway and its contributors, which can act as biomarkers of neuroinflammation or even offer potential new treatment targets for secondary neuronal cell death after SAH.
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Affiliation(s)
- Rebecca Heinz
- Experimental Neurosurgery, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10117 Berlin, Germany
| | - Ulf C. Schneider
- Experimental Neurosurgery, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10117 Berlin, Germany
- Department of Neurosurgery, Cantonal Hospital of Lucerne, 6000 Lucerne, Switzerland
- Correspondence:
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14
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Zhang C, Chen S. Role of TREM2 in the Development of Neurodegenerative Diseases After Traumatic Brain Injury. Mol Neurobiol 2022; 60:342-354. [PMID: 36264434 DOI: 10.1007/s12035-022-03094-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/14/2022] [Indexed: 11/28/2022]
Abstract
Traumatic brain injury (TBI) has been found as the primary cause of morbidity and disability worldwide, which has posed a significant social and economic burden. The first stage of TBI produces brain edema, axonal damage, and hypoxia, thus having an effect on the blood-brain barrier function, promoting inflammatory responses, and increasing oxidative stress. Patients with TBI are more likely to develop post-traumatic epilepsy, behavioral issues, as well as mental illnesses. The long-term effects arising from TBI have aroused rising attention over the past few years. Microglia in the brain can express the triggering receptor expressed on myeloid cells 2 (TREM2), which is a single transmembrane receptor pertaining to the immunoglobulin superfamily. The receptor has been correlated with a number of neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and other relevant diseases. In this review, it is demonstrated that TREM2 is promising to serve as a neuroprotective factor for neurodegenerative disorders following TBI by modulating the function of microglial cells. Accordingly, it has potential avenues for TREM2-related therapies to improve long-term recovery after TBI.
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Affiliation(s)
- Chunhao Zhang
- Department of Neurosurgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, People's Republic of China
| | - Shiwen Chen
- Department of Neurosurgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, People's Republic of China.
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15
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Cao M, Ma L, Yan C, Wang H, Ran M, Chen Y, Wang X, Liang X, Chai L, Li X. Mouse Ocilrp2/Clec2i negatively regulates LPS-mediated IL-6 production by blocking Dap12-Syk interaction in macrophage. Front Immunol 2022; 13:984520. [PMID: 36300111 PMCID: PMC9589251 DOI: 10.3389/fimmu.2022.984520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/20/2022] [Indexed: 11/24/2022] Open
Abstract
C-type lectin Ocilrp2/Clec2i is widely expressed in dendritic cells, lymphokine-activated killer cells and activated T cells. Previous studies have shown that Ocilrp2 is an important regulator in the activation of T cells and NK cells. However, the role of Ocilrp2 in the inflammatory responses by activated macrophages is currently unknown. This study investigated the expression of inflammatory cytokines in LPS-induced macrophages from primary peritoneal macrophages silenced by specific siRNA target Ocilrp2. Ocilrp2 was significantly downregulated in macrophages via NF-κB and pathways upon LPS stimuli or VSV infection. Silencing Ocilrp2 resulted in the increased expression of IL-6 in LPS-stimulated peritoneal macrophages and mice. Moreover, IL-6 expression was reduced in LPS-induced Ocilrp2 over-expressing iBMDM cells. Furthermore, we found that Ocilrp2-related Syk activation is responsible for expressing inflammatory cytokines in LPS-stimulated macrophages. Silencing Ocilrp2 significantly promotes the binding of Syk to Dap12. Altogether, we identified the Ocilrp2 as a critical role in the TLR4 signaling pathway and inflammatory macrophages’ immune regulation, and added mechanistic insights into the crosstalk between TLR and Syk signaling.
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Affiliation(s)
- Mingya Cao
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
- Institute of Translational Medicine, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Lina Ma
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Chenyang Yan
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Han Wang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Mengzhe Ran
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Ying Chen
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Xiao Wang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Xiaonan Liang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Lihui Chai
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
- Institute of Translational Medicine, School of Basic Medical Sciences, Henan University, Kaifeng, China
- *Correspondence: Lihui Chai, ; Xia Li,
| | - Xia Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
- Institute of Translational Medicine, School of Basic Medical Sciences, Henan University, Kaifeng, China
- *Correspondence: Lihui Chai, ; Xia Li,
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16
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Haure-Mirande JV, Audrain M, Ehrlich ME, Gandy S. Microglial TYROBP/DAP12 in Alzheimer's disease: Transduction of physiological and pathological signals across TREM2. Mol Neurodegener 2022; 17:55. [PMID: 36002854 PMCID: PMC9404585 DOI: 10.1186/s13024-022-00552-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/27/2022] [Indexed: 02/01/2023] Open
Abstract
TYROBP (also known as DAP12 or KARAP) is a transmembrane adaptor protein initially described as a receptor-activating subunit component of natural killer (NK) cells. TYROBP is expressed in numerous cell types, including peripheral blood monocytes, macrophages, dendritic cells, and osteoclasts, but a key point of recent interest is related to the critical role played by TYROBP in the function of many receptors expressed on the plasma membrane of microglia. TYROBP is the downstream adaptor and putative signaling partner for several receptors implicated in Alzheimer's disease (AD), including SIRP1β, CD33, CR3, and TREM2. TYROBP has received much of its current notoriety because of its importance in brain homeostasis by signal transduction across those receptors. In this review, we provide an overview of evidence indicating that the biology of TYROBP extends beyond its interaction with these four ligand-binding ectodomain-intramembranous domain molecules. In addition to reviewing the structure and localization of TYROBP, we discuss our recent progress using mouse models of either cerebral amyloidosis or tauopathy that were engineered to be TYROBP-deficient or TYROBP-overexpressing. Remarkably, constitutively TYROBP-deficient mice provided a model of genetic resilience to either of the defining proteinopathies of AD. Learning behavior and synaptic electrophysiological function were preserved at normal physiological levels even in the face of robust cerebral amyloidosis (in APP/PSEN1;Tyrobp-/- mice) or tauopathy (in MAPTP301S;Tyrobp-/- mice). A fundamental underpinning of the functional synaptic dysfunction associated with each proteotype was an accumulation of complement C1q. TYROBP deficiency prevented C1q accumulation associated with either proteinopathy. Based on these data, we speculate that TYROBP plays a key role in the microglial sensome and the emergence of the disease-associated microglia (DAM) phenotype. TYROBP may also play a key role in the loss of markers of synaptic integrity (e.g., synaptophysin-like immunoreactivity) that has long been held to be the feature of human AD molecular neuropathology that most closely correlates with concurrent clinical cognitive function.
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Affiliation(s)
| | - Mickael Audrain
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Michelle E. Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Sam Gandy
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Psychiatry and the NIA-Designated Mount Sinai Alzheimer’s Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- James J Peters VA Medical Center, New York, Bronx NY 10468 USA
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17
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Salamone A, Terrone G, Di Sapia R, Balosso S, Ravizza T, Beltrame L, Craparotta I, Mannarino L, Cominesi SR, Rizzi M, Pauletti A, Marchini S, Porcu L, Zimmer TS, Aronica E, During M, Abrahams B, Kondo S, Nishi T, Vezzani A. Cholesterol 24-hydroxylase is a novel pharmacological target for anti-ictogenic and disease modification effects in epilepsy. Neurobiol Dis 2022; 173:105835. [PMID: 35932989 DOI: 10.1016/j.nbd.2022.105835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/15/2022] [Accepted: 07/30/2022] [Indexed: 10/16/2022] Open
Abstract
Therapies for epilepsy mainly provide symptomatic control of seizures since most of the available drugs do not target disease mechanisms. Moreover, about one-third of patients fail to achieve seizure control. To address the clinical need for disease-modifying therapies, research should focus on targets which permit interventions finely balanced between optimal efficacy and safety. One potential candidate is the brain-specific enzyme cholesterol 24-hydroxylase. This enzyme converts cholesterol to 24S-hydroxycholesterol, a metabolite which among its biological roles modulates neuronal functions relevant for hyperexcitability underlying seizures. To study the role of cholesterol 24-hydroxylase in epileptogenesis, we administered soticlestat (TAK-935/OV935), a potent and selective brain-penetrant inhibitor of the enzyme, during the early disease phase in a mouse model of acquired epilepsy using a clinically relevant dose. During soticlestat treatment, the onset of epilepsy was delayed and the number of ensuing seizures was decreased by about 3-fold compared to vehicle-treated mice, as assessed by EEG monitoring. Notably, the therapeutic effect was maintained 6.5 weeks after drug wash-out when seizure number was reduced by about 4-fold and their duration by 2-fold. Soticlestat-treated mice showed neuroprotection of hippocampal CA1 neurons and hilar mossy cells as assessed by post-mortem brain histology. High throughput RNA-sequencing of hippocampal neurons and glia in mice treated with soticlestat during epileptogenesis showed that inhibition of cholesterol 24-hydroxylase did not directly affect the epileptogenic transcriptional network, but rather modulated a non-overlapping set of genes that might oppose the pathogenic mechanisms of the disease. In human temporal lobe epileptic foci, we determined that cholesterol 24-hydroxylase expression trends higher in neurons, similarly to epileptic mice, while the enzyme is ectopically induced in astrocytes compared to control specimens. Soticlestat reduced significantly the number of spontaneous seizures in chronic epileptic mice when was administered during established epilepsy. Data show that cholesterol 24-hydroxylase contributes to spontaneous seizures and is involved in disease progression, thus it represents a novel target for chronic seizures inhibition and disease-modification therapy in epilepsy.
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Affiliation(s)
- Alessia Salamone
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Gaetano Terrone
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Rossella Di Sapia
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Silvia Balosso
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Luca Beltrame
- Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Ilaria Craparotta
- Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Laura Mannarino
- Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Sara Raimondi Cominesi
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Massimo Rizzi
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Alberto Pauletti
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Sergio Marchini
- Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Luca Porcu
- Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Till S Zimmer
- Department of Neuropathology, Amsterdam UMC, 1105 Amsterdam, the Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam UMC, 1105 Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), 2103 Heemstede, the Netherlands
| | | | - Brett Abrahams
- Ovid Therapeutics, 10036 New York, NY, USA; Departments of Genetics and Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 10461 Bronx, USA
| | - Shinichi Kondo
- Takeda Pharmaceutical Company Limited, 251-8555 Fujisawa, Japan
| | - Toshiya Nishi
- Takeda Pharmaceutical Company Limited, 251-8555 Fujisawa, Japan
| | - Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy.
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18
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The role of Triggering Receptor Expressed on Myeloid Cells 2 in Parkinson's disease and other neurodegenerative disorders. Behav Brain Res 2022; 433:113977. [PMID: 35752274 DOI: 10.1016/j.bbr.2022.113977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/09/2022] [Accepted: 06/21/2022] [Indexed: 11/23/2022]
Abstract
Parkinson's disease (PD) is a progressive neurological disorder marked by cardinal clinical symptoms such as rigor, tremor, and akinesia. Albeit a loss of dopaminergic neurons from the substantia nigra pars compacta is causative for the movement impairments found in patients, molecular reasoning for this loss is still incomplete. In recent years, triggering factor expressed on myeloid cells (TREM2) gained attention in the field of neurodegeneration as it could be associated with different neurodegenerative disorders. Primarily identified as a risk factor in Alzheimer's disease, variants in TREM2 were linked to PD and multiple sclerosis, too. Expressed on phagocytic cells, such as macrophages and microglia, TREM2 puts the focus on inflammation associated conditions in PD and provides a molecular target that could at least partly explain the role of immune cells in PD. Here, we summarize expression patterns and molecular functions of TREM2, recapitulate on its role in inflammation, phagocytosis and cell survival, before turning to neurodegenerative disorders with an emphasis on PD.
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The transmembrane adapter SCIMP recruits tyrosine kinase Syk to phosphorylate Toll-like receptors to mediate selective inflammatory outputs. J Biol Chem 2022; 298:101857. [PMID: 35337798 PMCID: PMC9052152 DOI: 10.1016/j.jbc.2022.101857] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 11/23/2022] Open
Abstract
Innate immune signaling by Toll-like receptors (TLRs) involves receptor phosphorylation, which helps to shape and drive key inflammatory outputs, yet our understanding of the kinases and mechanisms that mediate TLR phosphorylation is incomplete. Spleen tyrosine kinase (Syk) is a nonreceptor protein tyrosine kinase, which is known to relay adaptive and innate immune signaling, including from TLRs. However, TLRs do not contain the conserved dual immunoreceptor tyrosine-based activation motifs that typically recruit Syk to many other receptors. One possibility is that the Syk-TLR association is indirect, relying on an intermediary scaffolding protein. We previously identified a role for the palmitoylated transmembrane adapter protein SCIMP in scaffolding the Src tyrosine kinase Lyn, for TLR phosphorylation, but the role of SCIMP in mediating the interaction between Syk and TLRs has not yet been investigated. Here, we show that SCIMP recruits Syk in response to lipopolysaccharide-mediated TLR4 activation. We also show that Syk contributes to the phosphorylation of SCIMP and TLR4 to enhance their binding. Further evidence pinpoints two specific phosphorylation sites in SCIMP critical for its interaction with Syk-SH2 domains in the absence of immunoreceptor tyrosine-based activation motifs. Finally, using inhibitors and primary macrophages from SCIMP-/- mice, we confirm a functional role for SCIMP-mediated Syk interaction in modulating TLR4 phosphorylation, signaling, and cytokine outputs. In conclusion, we identify SCIMP as a novel, immune-specific Syk scaffold, which can contribute to inflammation through selective TLR-driven inflammatory responses.
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20
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Syk Facilitates Influenza A Virus Replication by Restraining Innate Immunity at the Late Stage of Viral Infection. J Virol 2022; 96:e0020022. [PMID: 35293768 DOI: 10.1128/jvi.00200-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Spleen tyrosine kinase (Syk) has recently come forth as a critical regulator of innate immune response. Previous studies identify Syk as a key kinase for STAT1 activation at the early stage of influenza A virus (IAV) infection that is involved in initial antiviral immunity. However, the involvement of Syk in host antiviral immunity during the late phase of IAV infection and its effect on pathogenesis of the virus remain unknown. Here, we found through time course studies that Syk restrained antiviral immune response at the late stage of IAV infection, thereby promoting viral replication. Depletion of Syk suppressed IAV replication in vitro, whereas ectopic expression of Syk facilitated viral replication. Moreover, Syk-deficient mice were employed, and we observed that knockout of Syk rendered mice more resistant to IAV infection, as evidenced by a lower degree of lung injury, slower body weight loss, and an increased survival rate of Syk knockout mice challenged with IAV. Furthermore, we revealed that Syk repressed the interferon response at the late stage of viral infection. Loss of Syk potentiated the expression of type I and III interferons in both Syk-depleted cells and mice. Mechanistically, Syk interacted with TBK1 and modulated its phosphorylation status, thereby impeding TBK1 activation and restraining innate immune signaling that governs interferon response. Together, these findings unveil a role of Syk in temporally regulating host antiviral immunity and advance our understanding of complicated mechanisms underlying regulation of innate immunity against viral invasion. IMPORTANCE Innate immunity must be tightly controlled to eliminate invading pathogens while avoiding autoimmune or inflammatory diseases. Syk is essential for STAT1 activation at the early stage of IAV infection, which is critical for initial antiviral responses. Surprisingly, here a time course study showed that Syk suppressed innate immunity during late phases of IAV infection and thereby promoted IAV replication. Syk deficiency enhanced the expression of type I and III interferons, inhibited IAV replication, and rendered mice more resistant to IAV infection. Syk impaired innate immune signaling through impeding TBK1 activation. These data reveal that Syk participates in the initiation of antiviral defense against IAV infection and simultaneously contributes to the restriction of innate immunity at the late stage of viral infection, suggesting that Syk serves a dual function in regulating antiviral responses. This finding provides new insights into complicated mechanisms underlying interaction between virus and host immune system.
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21
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Kerget F, Kerget B, İba Yılmaz S, Kızıltunç A. Evaluation of the relationship between TREM-1/TREM-2 ratio and clinical course in COVID-19 pneumonia. Int J Clin Pract 2021; 75:e14697. [PMID: 34365706 PMCID: PMC8420347 DOI: 10.1111/ijcp.14697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/02/2021] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE The inflammatory/anti-inflammatory balance has an important role in the clinical course of SARS-CoV-2 infection (COVID-19), which has affected over 100 million people since it first appeared in China in December 2019. The aim of this study was to investigate the relationship between triggering receptor expressed on myeloid cells (TREM)-1/TREM-2 ratio and COVID-19 severity. METHODS A total of 171 individuals were included in the study: 121 patients who were admitted to the chest diseases department and intensive care unit of our hospital and diagnosed with COVID-19 by real-time PCR of nasopharyngeal swab samples from December 2020 to March 2021 and a control group consisting of 50 asymptomatic health workers in our hospital who had negative real-time PCR results during routine COVID-19 screening. RESULTS TREM-1 level was significantly higher in patients with severe disease compared with the moderate and control groups (P = .003, P = .001). TREM-2 levels did not differ significantly in moderate and severe patients (P = .36) but were significantly higher in both patient groups compared with the control group (P = .001 for both). TREM-1/TREM-2 ratio was significantly higher in the severe patient group than in the moderate and control groups (P = .001 for both). In receiver operating characteristic curve analysis of TREM-1/TREM-2 ratio in patients with moderate and severe COVID-19, the area under the curve was 0.723. Using a cut-off value of 0.125 for TREM-1/TREM-2 ratio in the Youden index calculation, the sensitivity was 60% and specificity was 71%. CONCLUSION Experience with the positive effects of medical treatments to restore inflammatory balance in the course of COVID-19 is steadily increasing. TREM-1 and TREM-2 have an important role in inflammation and may serve as biomarkers and therapeutic targets in the early treatment and follow-up of COVID-19.
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Affiliation(s)
- Ferhan Kerget
- Depertmant of Infection Diseases and Clinical MicrobiologyHealth Sciences University Erzurum Regional Education and Research HospitalErzurumTurkey
| | - Buğra Kerget
- Depertment of Pulmonary DiseasesAtaturk University School of MedicineErzurumTurkey
| | - Sibel İba Yılmaz
- Depertmant of Infection Diseases and Clinical MicrobiologyHealth Sciences University Erzurum Regional Education and Research HospitalErzurumTurkey
| | - Ahmet Kızıltunç
- Depertment of BiochemistryAtaturk University School of MedicineErzurumTurkey
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22
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Szumilas N, Corneth OBJ, Lehmann CHK, Schmitt H, Cunz S, Cullen JG, Chu T, Marosan A, Mócsai A, Benes V, Zehn D, Dudziak D, Hendriks RW, Nitschke L. Siglec-H-Deficient Mice Show Enhanced Type I IFN Responses, but Do Not Develop Autoimmunity After Influenza or LCMV Infections. Front Immunol 2021; 12:698420. [PMID: 34497606 PMCID: PMC8419311 DOI: 10.3389/fimmu.2021.698420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/27/2021] [Indexed: 12/02/2022] Open
Abstract
Siglec-H is a DAP12-associated receptor on plasmacytoid dendritic cells (pDCs) and microglia. Siglec-H inhibits TLR9-induced IFN-α production by pDCs. Previously, it was found that Siglec-H-deficient mice develop a lupus-like severe autoimmune disease after persistent murine cytomegalovirus (mCMV) infection. This was due to enhanced type I interferon responses, including IFN-α. Here we examined, whether other virus infections can also induce autoimmunity in Siglec-H-deficient mice. To this end we infected Siglec-H-deficient mice with influenza virus or with Lymphocytic Choriomeningitis virus (LCMV) clone 13. With both types of viruses we did not observe induction of autoimmune disease in Siglec-H-deficient mice. This can be explained by the fact that both types of viruses are ssRNA viruses that engage TLR7, rather than TLR9. Also, Influenza causes an acute infection that is rapidly cleared and the chronicity of LCMV clone 13 may not be sufficient and may rather suppress pDC functions. Siglec-H inhibited exclusively TLR-9 driven type I interferon responses, but did not affect type II or type III interferon production by pDCs. Siglec-H-deficient pDCs showed impaired Hck expression, which is a Src-family kinase expressed in myeloid cells, and downmodulation of the chemokine receptor CCR9, that has important functions for pDCs. Accordingly, Siglec-H-deficient pDCs showed impaired migration towards the CCR9 ligand CCL25. Furthermore, autoimmune-related genes such as Klk1 and DNase1l3 are downregulated in Siglec-H-deficient pDCs as well. From these findings we conclude that Siglec-H controls TLR-9-dependent, but not TLR-7 dependent inflammatory responses after virus infections and regulates chemokine responsiveness of pDCs.
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Affiliation(s)
- Nadine Szumilas
- Division of Genetics, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Odilia B J Corneth
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Christian H K Lehmann
- Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital Erlangen, Erlangen, Germany.,Deutsches Zentrum Immuntherapie (DZI), University Hospital Erlangen, University of Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), University of Erlangen-Nürnberg, Erlangen, Germany
| | - Heike Schmitt
- First Department of Medicine, University Hospital Erlangen, Erlangen, Germany
| | - Svenia Cunz
- Division of Genetics, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Jolie G Cullen
- Division of Animal Physiology and Immunology, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Talyn Chu
- Division of Animal Physiology and Immunology, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Anita Marosan
- Department of Immune Modulation, University Hospital Erlangen, Erlangen, Germany
| | - Attila Mócsai
- Semmelweis University School of Medicine, Budapest, Hungary
| | - Vladimir Benes
- Genomics Core Facility, EMBL Heidelberg, Heidelberg, Germany
| | - Dietmar Zehn
- Division of Animal Physiology and Immunology, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Diana Dudziak
- Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital Erlangen, Erlangen, Germany.,Deutsches Zentrum Immuntherapie (DZI), University Hospital Erlangen, University of Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), University of Erlangen-Nürnberg, Erlangen, Germany
| | - Rudi W Hendriks
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands
| | - Lars Nitschke
- Division of Genetics, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), University of Erlangen-Nürnberg, Erlangen, Germany
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23
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Kambaru A, Chaudhary N. Role of Protein Tyrosine Phosphatase in Regulation of Cell Signaling Cascades Affecting Tumor Cell Growth: A Future Perspective as Anti- Cancer Drug Target. Curr Pharm Biotechnol 2021; 23:920-931. [PMID: 34375185 DOI: 10.2174/1389201022666210810094739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 06/05/2021] [Accepted: 06/06/2021] [Indexed: 11/22/2022]
Abstract
Protein Tyrosine Phosphatase (PTP) superfamily is a key enzyme involved in the regulation of growth-related cell signaling cascades, such as the RAS/MAPK pathway, that directly affect cancer cell growth and metastasis. Several studies have indicated that the drug resistance observed in several late-stage tumors might also be affected by the levels of PTP in the cell. Hence, these phosphatases have been in the limelight for the past few decades as potential drug-targets and several promising drug candidates have been developed, even though none of these drugs have reached the market yet. In this review, we explore the potential of PTP as a viable anti-cancer drug target by studying PTPs, their regulation of several key cancer cell signaling pathways and how their levels affect various types of cancer. Furthermore, we present the current scenario of PTP as a molecular target and the various challenges faced in the development of PTP-targeting anti-cancer drugs.
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Affiliation(s)
| | - Nidhee Chaudhary
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Noida, India
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24
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Zuo Y, Deng GM. Fc Gamma Receptors as Regulators of Bone Destruction in Inflammatory Arthritis. Front Immunol 2021; 12:688201. [PMID: 34248975 PMCID: PMC8262610 DOI: 10.3389/fimmu.2021.688201] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/09/2021] [Indexed: 12/29/2022] Open
Abstract
Bone erosion is one of the primary features of inflammatory arthritis and is caused by excessive differentiation and activation of osteoclasts. Fc gamma receptors (FcγRs) have been implicated in osteoclastogenesis. Our recent studies demonstrate that joint-deposited lupus IgG inhibited RANKL-induced osteoclastogenesis. FcγRI is required for RANKL-induced osteoclastogenesis and lupus IgG-induced signaling transduction. We reviewed the results of studies that analyzed the association between FcγRs and bone erosion in inflammatory arthritis. The analysis revealed the dual roles of FcγRs in bone destruction in inflammatory arthritis. Thus, IgG/FcγR signaling molecules may serve as potential therapeutic targets against bone erosion.
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Affiliation(s)
- Yuyue Zuo
- Department of Rheumatology and Immunology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guo-Min Deng
- Department of Rheumatology and Immunology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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25
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Shafi S, Singh A, Ibrahim AM, Alhajri N, Abu Izneid T, Pottoo FH. Role of triggering receptor expressed on myeloid cells 2 (TREM2) in neurodegenerative dementias. Eur J Neurosci 2021; 53:3294-3310. [PMID: 33786894 DOI: 10.1111/ejn.15215] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 03/22/2021] [Indexed: 01/04/2023]
Abstract
Neurodegeneration is a debilitating condition that causes nerve cell degeneration or death. Neurodegenerative diseases (NDDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), frontotemporal dementia (FTD), and Lewy body dementia (LBD) are posing a larger population burden of dementia worldwide. Neurodegenerative dementia is one of the main challenges in public health with its main characteristics being permanent loss of memory, impairment in cognition, and impaired daily functions. The published literature about genetic studies of these disorders suggests genetic underpinning in the pathogenesis of neurodegenerative dementia. In the process of underlining the pathogenesis of NDD, growing evidence has related genetic variations in the triggering receptor expressed on myeloid cells 2 (TREM2). This review paper aims to provide a detailed information regarding the association of TREM2 and NDDs leading to dementia. A central consideration is AD that accounts for almost 50%-70% of all late-life dementias alone or in combination with other neurological disorders. Other prevalent neurodegenerative conditions that lead to dementia are also discussed. Such studies are important as they can give a comprehensive knowledge of TREM2's role in various NDDs, in order to maximize the potential for developing new therapeutic approaches.
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Affiliation(s)
- Sadat Shafi
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Archu Singh
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Abdallah Mohammad Ibrahim
- Fundamentals of Nursing Department, College of Nursing, Imam Abdul Rahman Bin Faisal University, Dammam, Saudi Arabia
| | - Noora Alhajri
- Department of Epidemiology and Population Health, College of Medicine and Health Science, Khalifa University, Abu Dhabi, UAE
| | | | - Faheem Hyder Pottoo
- Department of Pharmacology, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Damman, Saudi Arabia
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26
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Müller BJ, Westheider A, Birkner K, Seelig B, Kirschnek S, Bogdan C, von Loewenich FD. Anaplasma phagocytophilum Induces TLR- and MyD88-Dependent Signaling in In Vitro Generated Murine Neutrophils. Front Cell Infect Microbiol 2021; 11:627630. [PMID: 33747981 PMCID: PMC7970703 DOI: 10.3389/fcimb.2021.627630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/11/2021] [Indexed: 11/13/2022] Open
Abstract
Anaplasma phagocytophilum is a tick-transmitted obligate intracellular Gram-negative bacterium that replicates in neutrophils. It elicits febrile disease in humans and in animals. In a mouse model, elimination of A. phagocytophilum required CD4+ T cells, but was independent of IFN-γ and other classical antibacterial effector mechanisms. Further, mice deficient for immune recognition and signaling via Toll-like receptor (TLR) 2, TLR4 or MyD88 were unimpaired in pathogen control. In contrast, animals lacking adaptor molecules of Nod-like receptors (NLR) such as RIP2 or ASC showed delayed clearance of A. phagocytophilum. In the present study, we investigated the contribution of further pattern recognition receptor (PRR) pathways to the control of A. phagocytophilum in vivo. Mice deficient for the NLR NOD2 had elevated bacterial loads in the early phase of infection, but were unimpaired in pathogen elimination. In contrast, animals lacking adaptor proteins of different C-type lectin receptors (CLR) such as DAP12, Fc-receptor γ-chain (FcRγ) and SYK controlled A. phagocytophilum as efficiently as wild-type mice. Further, we investigated which PRR pathways are involved in the sensing of A. phagocytophilum by in vitro generated Hoxb8 murine neutrophils. In vitro, recognition of A. phagocytophilum by murine neutrophils was dependent on TLR- and MyD88 signaling. However, it remained intact in the absence of the NLR NOD1, NOD2 and NALP3 and of the CLR adaptor molecules DAP12 and FcRγ. From these results, we conclude that TLR rather than NLR or CLR are critical for the detection of A. phagocytophilum by neutrophils although in vivo defective TLR-signaling is compensated probably because of the redundancy of the immune system.
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Affiliation(s)
- Beate J Müller
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
| | - Arne Westheider
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
| | - Katharina Birkner
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
| | - Birte Seelig
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
| | - Susanne Kirschnek
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg, Germany
| | - Christian Bogdan
- Mikrobiologisches Institut-Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
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27
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TREM2, microglia, and Alzheimer's disease. Mech Ageing Dev 2021; 195:111438. [PMID: 33516818 DOI: 10.1016/j.mad.2021.111438] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/02/2021] [Accepted: 01/17/2021] [Indexed: 12/19/2022]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) has been suggested to play a crucial role in Alzheimer's disease (AD) pathogenesis, as revealed by genome-wide association studies (GWAS). Since then, rapidly increasing literature related to TREM2 has focused on elucidating its role in AD pathology. In this review, we summarize our understanding of TREM2 biology, explore TREM2 functions in microglia, address the multiple mechanisms of TREM2 in AD, and raise key questions for further investigations to elucidate the detailed roles and molecular mechanisms of TREM2 in microglial responses. A major breakthrough in our understanding of TREM2 is based on our hypothesis suggesting that TREM2 may act as a multifaceted player in microglial functions in AD brain homeostasis. We conclude that TREM2 can not only influence microglial functions in amyloid and tau pathologies but also participate in inflammatory responses and metabolism, acting alone or with other molecules, such as apolipoprotein E (APOE). This review provides novel insight into the broad role of TREM2 in microglial function in AD and enables us to develop new strategies aimed at the immune system to treat AD pathogenesis.
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28
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Brown MR, Radford SE, Hewitt EW. Modulation of β-Amyloid Fibril Formation in Alzheimer's Disease by Microglia and Infection. Front Mol Neurosci 2020; 13:609073. [PMID: 33324164 PMCID: PMC7725705 DOI: 10.3389/fnmol.2020.609073] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 11/03/2020] [Indexed: 01/06/2023] Open
Abstract
Amyloid plaques are a pathological hallmark of Alzheimer's disease. The major component of these plaques are highly ordered amyloid fibrils formed by amyloid-β (Aβ) peptides. However, whilst Aβ amyloid fibril assembly has been subjected to detailed and extensive analysis in vitro, these studies may not reproduce how Aβ fibrils assemble in the brain. This is because the brain represents a highly complex and dynamic environment, and in Alzheimer's disease multiple cofactors may affect the assembly of Aβ fibrils. Moreover, in vivo amyloid plaque formation will reflect the balance between the assembly of Aβ fibrils and their degradation. This review explores the roles of microglia as cofactors in Aβ aggregation and in the clearance of amyloid deposits. In addition, we discuss how infection may be an additional cofactor in Aβ fibril assembly by virtue of the antimicrobial properties of Aβ peptides. Crucially, by understanding the roles of microglia and infection in Aβ amyloid fibril assembly it may be possible to identify new therapeutic targets for Alzheimer's disease.
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Affiliation(s)
- Madeleine R Brown
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Sheena E Radford
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Eric W Hewitt
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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29
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Sun H, Feng J, Tang L. Function of TREM1 and TREM2 in Liver-Related Diseases. Cells 2020; 9:2626. [PMID: 33297569 PMCID: PMC7762355 DOI: 10.3390/cells9122626] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 02/07/2023] Open
Abstract
TREM1 and TREM2 are members of the triggering receptors expressed on myeloid cells (TREM) family. Both TREM1 and TREM2 are immunoglobulin superfamily receptors. Their main function is to identify foreign antigens and toxic substances, thereby adjusting the inflammatory response. In the liver, TREM1 and TREM2 are expressed on non-parenchymal cells, such as liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells, and cells which infiltrate the liver in response to injury including monocyte-derived macrophages and neutrophils. The function of TREM1 and TREM2 in inflammatory response depends on Toll-like receptor 4. TREM1 mainly augments inflammation during acute inflammation, while TREM2 mainly inhibits chronic inflammation to protect the liver from pathological changes. Chronic inflammation often induces metabolic abnormalities, fibrosis, and tumorigenesis. The above physiological changes lead to liver-related diseases, such as liver injury, nonalcoholic steatohepatitis, hepatic fibrosis, and hepatocellular carcinoma. Here, we review the function of TREM1 and TREM2 in different liver diseases based on inflammation, providing a more comprehensive perspective for the treatment of liver-related diseases.
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Affiliation(s)
- Huifang Sun
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China;
| | - Jianguo Feng
- Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
| | - Liling Tang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China;
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30
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Wang Y, Lin Y, Wang L, Zhan H, Luo X, Zeng Y, Wu W, Zhang X, Wang F. TREM2 ameliorates neuroinflammatory response and cognitive impairment via PI3K/AKT/FoxO3a signaling pathway in Alzheimer's disease mice. Aging (Albany NY) 2020; 12:20862-20879. [PMID: 33065553 PMCID: PMC7655179 DOI: 10.18632/aging.104104] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 08/08/2020] [Indexed: 04/12/2023]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) has been shown with a neuroprotective function against inflammation and neuronal injury in Alzheimer's disease (AD). However, the TREM2 induced anti-inflammatory mechanism is still not well known. In this study it has been demonstrated that the expression of TREM2 was upregulated in hippocampus of 5xFAD mice, whereas TREM2 knock-out mediated by AAV significantly increased the levels of pro-inflammatory cytokines and aggravated cognitive defect. Additionally, FoxO3a, a downstream member of the PI3K/AKT pathway, could be activated by TREM2 defect via the PI3K/AKT signaling in 5xFAD mice. That suggests TREM2-induced protection is associated with the PI3K-FoxO3a axis. On the contrary, overexpression of TREM2 alleviated the LPS-induced inflammatory response and induced M2 phenotype microglia in vitro. This phenomenon can be abolished by applying the PI3K inhibitor LY294002, suggesting FoxO3a not only participates in TREM2-induced anti-inflammation response, but is also involved in regulating the phenotype of microglia. Taken together, our results show that the protective functions of TREM2, both in inflammatory response and cognitive impairment as well as in the decrease of M1 phenotype microglia, are related to PI3K/AKT/FoxO3a signaling pathway in AD mice.
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Affiliation(s)
- Yaping Wang
- Department of Rehabilitation, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yan Lin
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
- The First Affiliated Hospital, Southern Medical University, Guangzhou 510515, China
| | - Linhan Wang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
- The First Affiliated Hospital, Southern Medical University, Guangzhou 510515, China
| | - Hongrui Zhan
- Department of Rehabilitation, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Xiaoting Luo
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
- Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yanyan Zeng
- Department of Rehabilitation, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Wen Wu
- Department of Rehabilitation, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Xingmei Zhang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Fang Wang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
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31
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Kumar V. Toll-like receptors in sepsis-associated cytokine storm and their endogenous negative regulators as future immunomodulatory targets. Int Immunopharmacol 2020; 89:107087. [PMID: 33075714 PMCID: PMC7550173 DOI: 10.1016/j.intimp.2020.107087] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/04/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022]
Abstract
Sepsis infects more than 48.9 million people world-wide, with 19.7 million deaths. Cytokine storm plays a significant role in sepsis, along with severe COVID-19. TLR signaling pathways plays a crucial role in generating the cytokine storm. Endogenous negative regulators of TLR signaling are crucial to regulate cytokine storm.
Cytokine storm generates during various systemic acute infections, including sepsis and current pandemic called COVID-19 (severe) causing devastating inflammatory conditions, which include multi-organ failure or multi-organ dysfunction syndrome (MODS) and death of the patient. Toll-like receptors (TLRs) are one of the major pattern recognition receptors (PRRs) expressed by immune cells as well as non-immune cells, including neurons, which play a crucial role in generating cytokine storm. They recognize microbial-associated molecular patterns (MAMPs, expressed by pathogens) and damage or death-associate molecular patterns (DAMPs; released and/expressed by damaged/killed host cells). Upon recognition of MAMPs and DAMPs, TLRs activate downstream signaling pathways releasing several pro-inflammatory mediators [cytokines, chemokines, interferons, and reactive oxygen and nitrogen species (ROS or RNS)], which cause acute inflammation meant to control the pathogen and repair the damage. Induction of an exaggerated response due to genetic makeup of the host and/or persistence of the pathogen due to its evasion mechanisms may lead to severe systemic inflammatory condition called sepsis in response to the generation of cytokine storm and organ dysfunction. The activation of TLR-induced inflammatory response is hardwired to the induction of several negative feedback mechanisms that come into play to conclude the response and maintain immune homeostasis. This state-of-the-art review describes the importance of TLR signaling in the onset of the sepsis-associated cytokine storm and discusses various host-derived endogenous negative regulators of TLR signaling pathways. The subject is very important as there is a vast array of genes and processes implicated in these negative feedback mechanisms. These molecules and mechanisms can be targeted for developing novel therapeutic drugs for cytokine storm-associated diseases, including sepsis, severe COVID-19, and other inflammatory diseases, where TLR-signaling plays a significant role.
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Affiliation(s)
- V Kumar
- Children Health Clinical Unit, Faculty of Medicine, Mater Research, University of Queensland, ST Lucia, Brisbane, Queensland 4078, Australia; School of Biomedical Sciences, Faculty of Medicine, University of Queensland, ST Lucia, Brisbane, Queensland 4078, Australia.
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32
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Angata T. Siglecs that Associate with DAP12. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1204:215-230. [PMID: 32152949 DOI: 10.1007/978-981-15-1580-4_9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Siglecs are a family of transmembrane receptor-like glycan-recognition proteins expressed primarily on leukocytes. Majority of Siglecs have an intracellular sequence motif called immunoreceptor tyrosine-based inhibitory motif (ITIM) and associate with Src homology region 2 domain-containing tyrosine phosphatase-1 (SHP-1), and negatively regulate tyrosine phosphorylation-mediated intracellular signaling events. On the other hand, some Siglecs have a positively charged amino acid residue in the transmembrane domain and associate with DNAX activation protein of 12 kDa (DAP12), which in turn recruits spleen tyrosine kinase (Syk). These DAP12-associated Siglecs play diverse functions. For example, Siglec-15 is conserved throughout vertebrate evolution and plays a role in bone homeostasis by regulating osteoclast development and function. Human Siglec-14 and -16 have inhibitory counterparts (Siglec-5 and -11, respectively), which show extremely high sequence similarity with them at the extracellular domain but interact with SHP-1. The DAP12-associated Siglec in such "paired receptor" configuration counteracts the pathogens that exploit the inhibitory counterpart. Polymorphisms (mutations) that render DAP12-associated inactive Siglecs are found in humans, and some of these appear to be associated with sensitivity or resistance of human hosts to bacterially induced conditions. Studies of mouse Siglec-H have revealed complex and intriguing functions it plays in regulating adaptive immunity. Many questions remain unanswered, and further molecular and genetic studies of DAP12-associated Siglecs will yield valuable insights with translational relevance.
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Affiliation(s)
- Takashi Angata
- Institute of Biological Chemistry, Academia Sinica, 128, Section 2, Academia Road, Nangang District, Taipei, Taiwan.
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Liu Y, Li R, Qiao S, Chen XX, Deng R, Zhang G. Porcine sialoadhesin suppresses type I interferon production to support porcine reproductive and respiratory syndrome virus infection. Vet Res 2020; 51:18. [PMID: 32093750 PMCID: PMC7038599 DOI: 10.1186/s13567-020-00743-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 01/13/2020] [Indexed: 12/21/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a significant threat to the global swine industry. Porcine sialoadhesin (poSn) has been previously shown to mediate PRRSV attachment and internalization. In the current study, we report its unidentified role in antagonism of type I interferon (IFN) production during PRRSV infection. We determined that poSn facilitated PRRSV infection via inhibition of type I IFN transcription. Mechanistically, poSn interacted with a 12 kDa DNAX-activation protein (DAP12), which was dependent on residues 51–57 within DAP12 transmembrane domain (TMD). PRRSV exploited the poSn-DAP12 pathway to attenuate activation of nuclear factor-kappa B (NF-κB). More importantly, the poSn-DAP12 pathway was involved in inhibiting poly (I:C)-triggered IFN production. All these results reveal a novel role of poSn in suppressing host antiviral responses, which deepens our understanding of PRRSV pathogenesis.
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Affiliation(s)
- Yingqi Liu
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China
| | - Rui Li
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China
| | - Songlin Qiao
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China
| | - Xin-Xin Chen
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China
| | - Ruiguang Deng
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China
| | - Gaiping Zhang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, 450002, China. .,College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450002, China.
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Zaher HA, Gawdat HI, Hegazy RA, Mohammed FN, Alorbani AM, Ibrahim NA, Sayed KS. Assessment of the role of spleen tyrosine kinase and zeta-chain-associated 70-kDa protein (tyrosine) kinase in the pathogenesis of psoriasis. Indian J Dermatol Venereol Leprol 2019; 86:85-87. [PMID: 31709999 DOI: 10.4103/ijdvl.ijdvl_2_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Hesham A Zaher
- Department of Dermatology, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Heba I Gawdat
- Department of Dermatology, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Rehab A Hegazy
- Department of Dermatology, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Faisal N Mohammed
- Department of Dermatology and Venereology, National Research Centre, Giza, Egypt
| | - Aya M Alorbani
- Department of Dermatology, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Nahed A Ibrahim
- Department of Chemical Pathology, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Khadiga Sayed Sayed
- Department of Dermatology, Faculty of Medicine, Cairo University, Giza, Egypt
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Nakao T, Ono Y, Dai H, Nakano R, Perez-Gutierrez A, Camirand G, Huang H, Geller DA, Thomson AW. DNAX Activating Protein of 12 kDa/Triggering Receptor Expressed on Myeloid Cells 2 Expression by Mouse and Human Liver Dendritic Cells: Functional Implications and Regulation of Liver Ischemia-Reperfusion Injury. Hepatology 2019; 70:696-710. [PMID: 30372546 PMCID: PMC6488456 DOI: 10.1002/hep.30334] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 10/03/2018] [Indexed: 12/26/2022]
Abstract
Liver interstitial dendritic cells (DCs) have been implicated in the control of ischemia-reperfusion injury (IRI) and host immune responses following liver transplantation. Mechanisms underlying these regulatory functions of hepatic DCs remain unclear. We have shown recently that the transmembrane immunoadaptor DNAX-activating protein of 12 kDa (DAP12) negatively regulates mouse liver DC maturation and proinflammatory and immune stimulatory functions. Here, we used PCR analysis and flow cytometry to characterize expression of DAP12 and its associated triggering receptor, triggering receptor expressed on myeloid cells 2 (TREM2), by mouse and human liver DCs and other immune cells compared with DCs in other tissues. We also examined the roles of DAP12 and TREM2 and their expression by liver DCs in the regulation of liver IRI. Injury was induced in DAP12-/- , TREM2-/- , or wild-type (WT) mice by 1 hour of 70% clamping and quantified following 6 hours of reperfusion. Both DAP12 and TREM2 were coexpressed at comparatively high levels by liver DCs. Mouse liver DCs lacking DAP12 or TREM2 displayed enhanced levels of nuclear factor κB and costimulatory molecule expression. Unlike normal WT liver DCs, DAP12-/- liver DC failed to inhibit proliferative responses of activated T cells. In vivo, DAP12-/- and TREM2-/- mice exhibited enhanced IRI accompanied by augmented liver DC activation. Elevated alanine aminotransferase levels and tissue injury were markedly reduced by infusion of WT but not DAP12-/- DC. Conclusion: Our data reveal a close association between DAP12 and TREM2 expression by liver DC and suggest that, by negatively regulating liver DC stimulatory function, DAP12 promotes their control of hepatic inflammatory responses; the DAP12/TREM2 signaling complex may represent a therapeutic target for control of acute liver injury/liver inflammatory disorders.
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Affiliation(s)
- Toshimasa Nakao
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yoshihiro Ono
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Helong Dai
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Department of Urological Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, P.R. China
| | - Ryosuke Nakano
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Angelica Perez-Gutierrez
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Geoffrey Camirand
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Hai Huang
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - David A. Geller
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Liver Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Angus W. Thomson
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Corresponding author: Angus W. Thomson, PhD DSc, Thomas E. Starzl Transplantation Institute, University of Pittsburgh School of Medicine, 200 Lothrop Street, W1540 BST, Pittsburgh, PA 15261, Phone: (412) 624-6392, Fax: (412)-624-1172,
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Key PN, Germino J, Yang L, Piersma SJ, Tripathy SK. Chronic Ly49H Receptor Engagement in vivo Decreases NK Cell Response to Stimulation Through ITAM-Dependent and Independent Pathways Both in vitro and in vivo. Front Immunol 2019; 10:1692. [PMID: 31396217 PMCID: PMC6664057 DOI: 10.3389/fimmu.2019.01692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/08/2019] [Indexed: 01/15/2023] Open
Abstract
Natural killer (NK) cells play an important role in the innate immune response. The summation of activation and inhibitory signals delivered through cell surface membrane receptors determines NK cell function. However, the continuous engagement of an activating receptor on NK cells appears to render the cells hyporesponsive to stimulation through other unrelated activating receptors. The mechanism by which this takes place remains unclear. Herein we demonstrate that continuous in vivo engagement of the Ly49H receptor with its ligand, m157, results in Ly49H+ NK cells that are hyporesponsive to further stimulation by other ITAM-dependent and independent receptors, while Ly49H− NK cells remain unaffected. The hyporesponsiveness of the NK cell correlates with the degree of Ly49H receptor downmodulation on its cell surface. We observe defects in calcium flux in the hyporesponsive NK cells following stimulation through the NK1.1 receptor. In addition, we observe differences in signaling molecules that play a role in calcium flux, including spleen tyrosine kinase (Syk) at baseline and phosphorylated phospholipase C gamma 2 (p-PLCγ2) at both baseline and following stimulation through NK1.1. We also demonstrate that various ITAM associated activation receptors, including Ly49H, remain associated with their respective adaptor molecules. With regard to in vivo NK cell function, we did not find differences in the formation of metastatic lung lesions following IV injection of B16 melanoma cells. However, we did observe defects in rejection of missing-self targets in vivo. The data suggest that continuous engagement of the Ly49H activating receptor on NK cells results in hyporesponsiveness of the NK cells to all of the ITAM-dependent and independent receptors we analyzed due to altered signaling pathways downstream of the receptor and adaptor molecule.
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Affiliation(s)
- Phillip N Key
- Gastroenterology Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Joe Germino
- Gastroenterology Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Liping Yang
- Rheumatology Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Sytse J Piersma
- Rheumatology Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Sandeep K Tripathy
- Gastroenterology Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
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Gervois P, Lambrichts I. The Emerging Role of Triggering Receptor Expressed on Myeloid Cells 2 as a Target for Immunomodulation in Ischemic Stroke. Front Immunol 2019; 10:1668. [PMID: 31379859 PMCID: PMC6650572 DOI: 10.3389/fimmu.2019.01668] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 07/03/2019] [Indexed: 01/18/2023] Open
Abstract
Stroke is the second most common cause of death and permanent disability. It is characterized by loss of neural tissue in which inflammation plays a crucial role in both the acute contribution to ischemic damage as in the late-stage impact on post-ischemic tissue regeneration. Microglia play a key role in the inflammatory stroke microenvironment as they can adapt a disease-promoting pro-inflammatory- or pro-regenerative phenotype thereby contributing to the exacerbation or alleviation of ischemic damage, respectively. Triggering receptor expressed on myeloid cells 2 (TREM2) is a cell surface receptor which in the central nervous system is mainly expressed on microglia. This receptor has been shown to play an essential role in microglial phagocytosis and function but its contribution in stroke pathobiology remains unclear. TREM2 was shown to be activated by nucleotides and lipid mediators, key factors that are secreted in the extracellular stroke environment by apoptotic neurons and cell/myelin debris. These factors in turn stimulate TREM2 signaling which mediates microglial migration toward- and phagocytosis of myelin debris and apoptotic cells. Moreover, microglial TREM2 appears to counteract the toll-like receptor response, thereby decreasing the production of pro-inflammatory cytokines. Finally, TREM2 is involved in microglial migration, survival, and is suggested to directly stimulate pro-regenerative phenotype shift. Therefore, this receptor is an attractive target for microglial modulation in the treatment of ischemic stroke and it provides additional information on microglial effector functions. This short review aims to elaborate on these TREM2-mediated microglial functions in the pathobiology and resolving of ischemic stroke.
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Affiliation(s)
- Pascal Gervois
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Ivo Lambrichts
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
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Patir A, Shih B, McColl BW, Freeman TC. A core transcriptional signature of human microglia: Derivation and utility in describing region-dependent alterations associated with Alzheimer's disease. Glia 2019; 67:1240-1253. [PMID: 30758077 DOI: 10.1002/glia.23572] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 11/06/2018] [Accepted: 11/12/2018] [Indexed: 12/23/2022]
Abstract
Growing recognition of the pivotal role microglia play in neurodegenerative and neuroinflammatory disorders has accentuated the need to characterize their function in health and disease. Studies in mouse have applied transcriptome-wide profiling of microglia to reveal key features of microglial ontogeny, functional profile, and phenotypic diversity. While similar, human microglia exhibit clear differences to their mouse counterparts, underlining the need to develop a better understanding of the human microglial profile. On examining published microglia gene signatures, limited consistency was observed between studies. Hence, we sought to derive a core microglia signature of the human central nervous system (CNS), through a comprehensive analysis of existing transcriptomic datasets. Nine datasets derived from cells and tissues, isolated from various regions of the CNS across numerous donors, were subjected independently to an unbiased correlation network analysis. From each dataset, a list of coexpressing genes corresponding to microglia was identified, with 249 genes highly conserved between them. This core signature included known microglial markers, and compared with other signatures provides a gene set specific to microglia in the context of the CNS. The utility of this signature was demonstrated by its use in detecting qualitative and quantitative region-specific alterations in aging and Alzheimer's disease. These analyses highlighted the reactive response of microglia in vulnerable brain regions such as the entorhinal cortex and hippocampus, additionally implicating pathways associated with disease progression. We believe this resource and the analyses described here, will support further investigations to the contribution of human microglia in CNS health and disease.
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Affiliation(s)
- Anirudh Patir
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom
| | - Barbara Shih
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom
| | - Barry W McColl
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom
- UK Dementia Research Institute at The University of Edinburgh, Edinburgh Medical School, The Chancellor's Building, 49 Little France Crescent, Edinburgh, United Kingdom
| | - Tom C Freeman
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom
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Zhou R, Chen Z, Hao D, Wang Y, Zhang Y, Yi X, Lyu LD, Liu H, Zou Q, Chu Y, Ge B, Yan D. Enterohemorrhagic Escherichia coli Tir inhibits TAK1 activation and mediates immune evasion. Emerg Microbes Infect 2019; 8:734-748. [PMID: 31130074 PMCID: PMC6542180 DOI: 10.1080/22221751.2019.1620589] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Many pathogens infect hosts through various immune evasion strategies. However, the molecular mechanisms by which pathogen proteins modulate and evade the host immune response remain unclear. Enterohemorrhagic Escherichia coli (EHEC) is a pathological strain that can induce mitogen-activated protein (MAP) kinase (Erk, Jnk and p38 MAPK) and NF-κB pathway activation and proinflammatory cytokine production, which then causes diarrheal diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Transforming growth factor β-activated kinase-1 (TAK1) is a key regulator involved in distinct innate immune signalling pathways. Here we report that EHEC translocated intimin receptor (Tir) protein inhibits the expression of EHEC-induced proinflammatory cytokines by interacting with the host tyrosine phosphatase SHP-1, which is dependent on the phosphorylation of immunoreceptor tyrosine-based inhibition motifs (ITIMs). Mechanistically, the association of EHEC Tir with SHP-1 facilitated the recruitment of SHP-1 to TAK1 and inhibited TAK1 phosphorylation, which then negatively regulated K63-linked polyubiquitination of TAK1 and downstream signal transduction. Taken together, these results suggest that EHEC Tir negatively regulates proinflammatory responses by inhibiting the activation of TAK1, which is essential for immune evasion and could be a potential target for the treatment of bacterial infection.
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Affiliation(s)
- Ruixue Zhou
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Zijuan Chen
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Doudou Hao
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Yu Wang
- b Department of Microbiology and Biochemical Pharmacy, National Engineering Research Centre of Immunological Products, College of Pharmacy , Army Medical University , Chongqing , People's Republic of China
| | - Yihua Zhang
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Xianfu Yi
- c School of Biomedical Engineering , Tianjin Medical University , Tianjin , People's Republic of China
| | - Liang-Dong Lyu
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Haipeng Liu
- d Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital , Tongji University School of Medicine , Shanghai , People's Republic of China
| | - Quanming Zou
- b Department of Microbiology and Biochemical Pharmacy, National Engineering Research Centre of Immunological Products, College of Pharmacy , Army Medical University , Chongqing , People's Republic of China
| | - Yiwei Chu
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
| | - Baoxue Ge
- d Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital , Tongji University School of Medicine , Shanghai , People's Republic of China.,e Department of Microbiology and Immunology , Tongji University School of Medicine , Shanghai , People's Republic of China
| | - Dapeng Yan
- a Department of Immunology, School of Basic Medical Sciences & Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology of MOE/MOH , Fudan University , Shanghai , People's Republic of China
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Nonmuscle Myosin Heavy Chain IIA Recognizes Sialic Acids on Sialylated RNA Viruses To Suppress Proinflammatory Responses via the DAP12-Syk Pathway. mBio 2019; 10:mBio.00574-19. [PMID: 31064828 PMCID: PMC6509187 DOI: 10.1128/mbio.00574-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
NMHC-IIA, a subunit of nonmuscle myosin IIA (NM-IIA), takes part in diverse physiological processes, including cell movement, cell shape maintenance, and signal transduction. Recently, NMHC-IIA has been demonstrated to be a receptor or factor contributing to viral infections. Here, we identified that NMHC-IIA recognizes sialic acids on sialylated RNA viruses, vesicular stomatitis virus (VSV) and porcine reproductive and respiratory syndrome virus (PRRSV). Upon recognition, NMHC-IIA associates with the transmembrane region of DAP12 to recruit Syk. Activation of the DAP12-Syk pathway impairs the host antiviral proinflammatory cytokine production and signaling cascades. More importantly, sialic acid mimics and sialylated RNA viruses enable the antagonism of LPS-triggered proinflammatory responses through engaging the NMHC-IIA–DAP12-Syk pathway. These results actually support that NMHC-IIA is involved in negative modulation of the host innate immune system, which provides a molecular basis for prevention and control of the sialylated RNA viruses and treatment of inflammatory diseases. Viral infections induce proinflammatory signaling cascades and inflammatory cytokine production, which is precisely regulated for host benefits. In the current study, we unravel a previously unappreciated role of nonmuscle myosin heavy chain IIA (NMHC-IIA) as a negative regulator in inflammatory responses. We identified that cell surface NMHC-IIA recognized sialic acids on sialylated RNA viruses during early infections and interacted with an immune adaptor DNAX activation protein of 12 kDa (DAP12) to recruit downstream spleen tyrosine kinase (Syk), leading to suppressed virus-triggered proinflammatory responses. More importantly, recognition of sialylated RNA viruses or sialic acid mimics by NMHC-IIA was shown to inhibit lipopolysaccharide (LPS)-induced proinflammatory responses via the DAP12-Syk pathway. These findings uncover a novel negative regulation mechanism of proinflammatory responses and provide a molecular basis to design anti-inflammatory drugs.
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Syk and Hrs Regulate TLR3-Mediated Antiviral Response in Murine Astrocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6927380. [PMID: 31089414 PMCID: PMC6476135 DOI: 10.1155/2019/6927380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/22/2018] [Accepted: 01/13/2019] [Indexed: 12/02/2022]
Abstract
Toll-like receptors (TLRs) sense the presence of pathogen-associated molecular patterns. Nevertheless, the mechanisms modulating TLR-triggered innate immune responses are not yet fully understood. Complex regulatory systems exist to appropriately direct immune responses against foreign or self-nucleic acids, and a critical role of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), endosomal sorting complex required for transportation-0 (ESCRT-0) subunit, has recently been implicated in the endolysosomal transportation of TLR7 and TLR9. We investigated the involvement of Syk, Hrs, and STAM in the regulation of the TLR3 signaling pathway in a murine astrocyte cell line C8-D1A following cell stimulation with a viral dsRNA mimetic. Our data uncover a relationship between TLR3 and ESCRT-0, point out Syk as dsRNA-activated kinase, and suggest the role for Syk in mediating TLR3 signaling in murine astrocytes. We show molecular events that occur shortly after dsRNA stimulation of astrocytes and result in Syk Tyr-342 phosphorylation. Further, TLR3 undergoes proteolytic processing; the resulting TLR3 N-terminal form interacts with Hrs. The knockdown of Syk and Hrs enhances TLR3-mediated antiviral response in the form of IFN-β, IL-6, and CXCL8 secretion. Understanding the role of Syk and Hrs in TLR3 immune responses is of high importance since activation and precise execution of the TLR3 signaling pathway in the brain seem to be particularly significant in mounting an effective antiviral defense. Infection of the brain with herpes simplex type 1 virus may increase the secretion of amyloid-β by neurons and astrocytes and be a causal factor in degenerative diseases such as Alzheimer's disease. Errors in TLR3 signaling, especially related to the precise regulation of the receptor transportation and degradation, need careful observation as they may disclose foundations to identify novel or sustain known therapeutic targets.
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Muraleedharan CK, McClellan SA, Ekanayaka SA, Francis R, Zmejkoski A, Hazlett LD, Xu S. The miR-183/96/182 Cluster Regulates Macrophage Functions in Response to Pseudomonas aeruginosa. J Innate Immun 2019; 11:347-358. [PMID: 30625496 DOI: 10.1159/000495472] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 11/01/2018] [Indexed: 12/13/2022] Open
Abstract
Macrophages (Mϕ) are an important component of the innate immune system; they play critical roles in the first line of defense to pathogen invasion and modulate adaptive immunity. MicroRNAs (miRNAs) are a newly recognized, important level of gene expression regulation. However, their roles in the regulation of Mϕ and the immune system are still not fully understood. In this report, we provide evidence that the conserved miR-183/96/182 cluster (miR-183/96/182) modulates Mϕ function in their production of reactive nitrogen (RNS) and oxygen species (ROS) and their inflammatory response to Pseudomonas aeruginosa (PA) infection and/or lipopolysaccharide (LPS) treatment. We show that knockdown of miR-183/96/182 results in decreased production of multiple proinflammatory cytokines in response to PA or LPS treatment in Mϕ-like Raw264.7 cells. Consistently, peritoneal Mϕ from miR-183/96/182-knockout versus wild-type mice are less responsive to PA or LPS, although their basal levels of proinflammatory cytokines are increased. In addition, overexpression of miR-183/96/182 results in decreased production of nitrite and ROS in Raw264.7 cells. We also provide evidence that DAP12 and Nox2 are downstream target genes of miR-183/96/182. These data suggest that miR-183/96/182 imposes global regulation on various aspects of Mϕ function through different downstream target genes.
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Affiliation(s)
- Chithra K Muraleedharan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Sharon A McClellan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Sandamali A Ekanayaka
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Rebecca Francis
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Alex Zmejkoski
- Irvin D. Reed Honors College, Wayne State University, Detroit, Michigan, USA
| | - Linda D Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Shunbin Xu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA,
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Anderson SR, Vetter ML. Developmental roles of microglia: A window into mechanisms of disease. Dev Dyn 2019; 248:98-117. [PMID: 30444278 PMCID: PMC6328295 DOI: 10.1002/dvdy.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/21/2018] [Accepted: 10/21/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia are engineers of the central nervous system (CNS) both in health and disease. In addition to the canonical immunological roles of clearing damaging entities and limiting the spread of toxicity and death, microglia remodel the CNS throughout life. While they have been extensively studied in disease and injury, due to their highly variable functions, their precise role in these contexts still remains uncertain. Over the past decade, we have greatly expanded our understanding of microglial function, including their essential homeostatic roles during development. Here, we review these developmental roles, identify parallels in disease, and speculate whether developmental mechanisms re-emerge in disease and injury. Developmental Dynamics 248:98-117, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Sarah R Anderson
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah
| | - Monica L Vetter
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah
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44
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Gratuze M, Leyns CEG, Holtzman DM. New insights into the role of TREM2 in Alzheimer's disease. Mol Neurodegener 2018; 13:66. [PMID: 30572908 PMCID: PMC6302500 DOI: 10.1186/s13024-018-0298-9] [Citation(s) in RCA: 280] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/28/2018] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia. The two histopathological markers of AD are amyloid plaques composed of the amyloid-β (Aβ) peptide, and neurofibrillary tangles of aggregated, abnormally hyperphosphorylated tau protein. The majority of AD cases are late-onset, after the age of 65, where a clear cause is still unknown. However, there are likely different multifactorial contributors including age, enviornment, biology and genetics which can increase risk for the disease. Genetic predisposition is considerable, with heritability estimates of 60-80%. Genetic factors such as rare variants of TREM2 (triggering receptor expressed on myeloid cells-2) strongly increase the risk of developing AD, confirming the role of microglia in AD pathogenesis. In the last 5 years, several studies have dissected the mechanisms by which TREM2, as well as its rare variants affect amyloid and tau pathologies and their consequences in both animal models and in human studies. In this review, we summarize increases in our understanding of the involvement of TREM2 and microglia in AD development that may open new therapeutic strategies targeting the immune system to influence AD pathogenesis.
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Affiliation(s)
- Maud Gratuze
- Department of Neurology, St. Louis, USA
- Hope Center for Neurological Disorders, St. Louis, USA
- Knight Alzheimer’s Disease Research Center, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Cheryl E. G. Leyns
- Department of Neurology, St. Louis, USA
- Hope Center for Neurological Disorders, St. Louis, USA
- Knight Alzheimer’s Disease Research Center, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - David M. Holtzman
- Department of Neurology, St. Louis, USA
- Hope Center for Neurological Disorders, St. Louis, USA
- Knight Alzheimer’s Disease Research Center, Washington University School of Medicine, St. Louis, MO 63110 USA
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Yang M, Xu W, Wang Y, Jiang X, Li Y, Yang Y, Yuan H. CD11b-activated Src signal attenuates neuroinflammatory pain by orchestrating inflammatory and anti-inflammatory cytokines in microglia. Mol Pain 2018; 14:1744806918808150. [PMID: 30280656 PMCID: PMC6311569 DOI: 10.1177/1744806918808150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Neuroinflammation plays an important role in the induction and maintenance of chronic pain. Orchestra of pattern-recognition receptor-induced pro-inflammatory and anti-inflammatory cytokines is critical for inflammation homeostasis. CD11b on macrophages could inhibit toll-like receptor (TLR) activation-induced inflammatory responses. However, the function of CD11b on microglia remains unknown. In the current study, we demonstrated that CD11b-deficient microglia cells produced more inflammatory cytokines, such as interleukin-6 and tumor necrosis factor alpha, while less anti-inflammatory cytokines. Signal transduction assay confirmed that nuclear factor-κB activation was increased in CD11b-deficient microglia cells, which resulted from decreased activation of Src. Inhibition of Src by PP1 increased inflammation in wild-type microglia cells significantly, but not in CD11b-deficient microglia cells. In vivo, CD11b-deficient mice were more susceptible to chronic constrictive injury-induced allodynia and hyperalgesia with significantly more inflammatory cytokines expression. All these results indicated that the regulatory function of CD11b-Src signal pathway on both inflammatory and anti-inflammatory cytokines in microglia cells is a potential target in neuropathic pain treatment.
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Affiliation(s)
- Mei Yang
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Wenyun Xu
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Yiru Wang
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Xin Jiang
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Yingke Li
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Yajuan Yang
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Hongbin Yuan
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
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Jelenčić V, Šestan M, Kavazović I, Lenartić M, Marinović S, Holmes TD, Prchal-Murphy M, Lisnić B, Sexl V, Bryceson YT, Wensveen FM, Polić B. NK cell receptor NKG2D sets activation threshold for the NCR1 receptor early in NK cell development. Nat Immunol 2018; 19:1083-1092. [PMID: 30224819 PMCID: PMC6166863 DOI: 10.1038/s41590-018-0209-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 08/17/2018] [Indexed: 12/21/2022]
Abstract
The activation of natural killer (NK) cells depends on a change in the balance of signals from inhibitory and activating receptors. The activation threshold values of NK cells are thought to be set by engagement of inhibitory receptors during development. Here, we found that the activating receptor NKG2D specifically set the activation threshold for the activating receptor NCR1 through a process that required the adaptor DAP12. As a result, NKGD2-deficient (Klrk1-/-) mice controlled tumors and cytomegalovirus infection better than wild-type controls through the NCR1-induced production of the cytokine IFN-γ. Expression of NKG2D before the immature NK cell stage increased expression of the adaptor CD3ζ. Reduced expression of CD3ζ in Klrk1-/- mice was associated with enhanced signal transduction through NCR1 and CD3ζ-deficiency resulted in hyper-responsiveness to stimulation via NCR1. Thus, an activating receptor developmentally set the activity of another activating receptor on NK cells and determined NK cell-reactivity to cellular threats.
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Affiliation(s)
- Vedrana Jelenčić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Marko Šestan
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Inga Kavazović
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Maja Lenartić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Sonja Marinović
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Tim D Holmes
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Michaela Prchal-Murphy
- Institute of Pharmacology and Toxicology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Berislav Lisnić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Veronika Sexl
- Institute of Pharmacology and Toxicology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Yenan T Bryceson
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden.,Broegelmann Laboratory, Department of Clinical Sciences, University of Bergen, Bergen, Norway
| | - Felix M Wensveen
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Bojan Polić
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.
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Dwarakanath BS, Farooque A, Gupta S. Targeting regulatory T cells for improving cancer therapy: Challenges and prospects. Cancer Rep (Hoboken) 2018; 1:e21105. [PMID: 32729245 DOI: 10.1002/cnr2.1105] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/22/2018] [Accepted: 04/07/2018] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Regulatory T cells (Tregs) play a central role in immune responses to infectious agents and tumors. Paradoxically, Tregs protect self-cells from the immune response as a part of peripheral tolerance and prevents autoimmune disorders, whereas during the process of carcinogenesis, they are exploited by tumor cells for protection against antitumor immune responses. Therefore, Tregs are often considered as a major obstacle in anticancer therapy. The objective of this review is to provide a current understanding on Tregs as a potential cellular target for achieving therapeutic gain and discuss various approaches that are implicated at preclinical and clinical scenario. RECENT FINDINGS Several approaches like immunotherapy and adjuvant chemotherapy, which reduce Tregs population, have been found to be useful in improving local tumor control. Our recent observations with the glycolytic inhibitor, 2-deoxy-D-glucose, established as an adjuvant in radiotherapy and chemotherapy of tumors also show that potential of 2-deoxy-D-glucose to improve local tumor control is linked with its ability to reduce the Tregs pool. CONCLUSIONS Several published studies and emerging evidences indicate that suppression of Treg numbers, infiltration into the tumors, and function can improve the cancer therapy by enhancing the antitumor immunity.
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Affiliation(s)
| | | | - Seema Gupta
- Department of Oncology, Georgetown University, Washington, DC, USA
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Disease-Associated Microglia: A Universal Immune Sensor of Neurodegeneration. Cell 2018; 173:1073-1081. [DOI: 10.1016/j.cell.2018.05.003] [Citation(s) in RCA: 717] [Impact Index Per Article: 119.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/17/2018] [Accepted: 04/29/2018] [Indexed: 11/18/2022]
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Ono Y, Perez-Gutierrez A, Nakao T, Dai H, Camirand G, Yoshida O, Yokota S, Stolz DB, Ross MA, Morelli AE, Geller DA, Thomson AW. Graft-infiltrating PD-L1 hi cross-dressed dendritic cells regulate antidonor T cell responses in mouse liver transplant tolerance. Hepatology 2018; 67:1499-1515. [PMID: 28921638 PMCID: PMC5856603 DOI: 10.1002/hep.29529] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/17/2017] [Accepted: 09/12/2017] [Indexed: 01/07/2023]
Abstract
UNLABELLED Although a key role of cross-dressing has been established in immunity to viral infection and more recently in the instigation of transplant rejection, its role in tolerance is unclear. We investigated the role of intragraft dendritic cells (DCs) and cross-dressing in mouse major histocompatibility complex (MHC)-mismatched liver transplant tolerance that occurs without therapeutic immunosuppression. Although donor interstitial DCs diminished rapidly after transplantation, they were replaced in the liver by host DCs that peaked on postoperative day (POD) 7 and persisted indefinitely. Approximately 60% of these recipient DCs displayed donor MHC class I, indicating cross-dressing. By contrast, only a very minor fraction (0%-2%) of cross-dressed DCs (CD-DCs) was evident in the spleen. CD-DCs sorted from liver grafts expressed much higher levels of T cell inhibitory programed death ligand 1 (PD-L1) and high levels of interleukin-10 compared with non-CD-DCs (nCD-DCs) isolated from the graft. Concomitantly, high incidences of programed death protein 1 (PD-1)hi T cell immunoglobulin and mucin domain containing 3 (TIM-3)+ exhausted graft-infiltrating CD8+ T cells were observed. Unlike nCD-DCs, the CD-DCs failed to stimulate proliferation of allogeneic T cells but markedly suppressed antidonor host T cell proliferation. CD-DCs were much less evident in allografts from DNAX-activating protein of 12 kDa (DAP12)-/- donors that were rejected acutely. CONCLUSION These findings suggest that graft-infiltrating PD-L1hi CD-DCs may play a key role in the regulation of alloimmunity and in the induction of liver transplant tolerance. (Hepatology 2018;67:1499-1515).
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Affiliation(s)
- Yoshihiro Ono
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Angelica Perez-Gutierrez
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Toshimasa Nakao
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Helong Dai
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Geoffrey Camirand
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Osamu Yoshida
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Shinichiro Yokota
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Donna Beer Stolz
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mark A. Ross
- Center for Biologic Imaging, Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Adrian E. Morelli
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - David A. Geller
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Liver Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Angus W. Thomson
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA,Corresponding author: Angus W. Thomson, PhD DSc, University of Pittsburgh School of Medicine, 200 Lothrop Street, W1540 BST, Pittsburgh, PA 15261, Phone: (412) 624-6392, Fax: (412)-624-1172,
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Dukovska D, Fernández-Soto D, Valés-Gómez M, Reyburn HT. NKG2H-Expressing T Cells Negatively Regulate Immune Responses. Front Immunol 2018; 9:390. [PMID: 29545803 PMCID: PMC5837990 DOI: 10.3389/fimmu.2018.00390] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 02/12/2018] [Indexed: 01/03/2023] Open
Abstract
The biology and function of NKG2H receptor, unlike the better characterized members of the NKG2 family NKG2A, NKG2C, and NKG2D, remains largely unclear. Here, we show that NKG2H is able to associate with the signaling adapter molecules DAP12 and DAP10 suggesting that this receptor can signal for cell activation. Using a recently described NKG2H-specific monoclonal antibody (mAb), we have characterized the expression and function of lymphocytes that express this receptor. NKG2H is expressed at the cell surface of a small percentage of peripheral blood mononuclear cell (PBMC) and is found more frequently on T cells, rather than NK cells. Moreover, although NKG2H is likely to trigger activation, co-cross-linking of this receptor with an NKG2H-specific mAb led to decreased T cell activation and proliferation in polyclonal PBMC cultures stimulated by anti-CD3 mAbs. This negative regulatory activity was seen only after cross-linking with NKG2H, but not NKG2A- or NKG2C-specific monoclonal antibodies. The mechanism underlying this negative effect is as yet unclear, but did not depend on the release of soluble factors or recognition of MHC class I molecules. These observations raise the intriguing possibility that NKG2H may be a novel marker for T cells able to negatively regulate T cell responses.
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Affiliation(s)
- Daniela Dukovska
- Department of Immunology and Oncology, National Centre for Biotechnology, CSIC, Madrid, Spain
| | - Daniel Fernández-Soto
- Department of Immunology and Oncology, National Centre for Biotechnology, CSIC, Madrid, Spain
| | - Mar Valés-Gómez
- Department of Immunology and Oncology, National Centre for Biotechnology, CSIC, Madrid, Spain
| | - Hugh T Reyburn
- Department of Immunology and Oncology, National Centre for Biotechnology, CSIC, Madrid, Spain
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