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Telemaco Contreras Colmenares M, de Oliveira Matos A, Henrique Dos Santos Dantas P, Rodrigues do Carmo Neto J, Silva-Sales M, Sales-Campos H. Unveiling the impact of TREM-2 + Macrophages in metabolic disorders. Cell Immunol 2024; 405-406:104882. [PMID: 39369473 DOI: 10.1016/j.cellimm.2024.104882] [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: 07/03/2024] [Accepted: 10/01/2024] [Indexed: 10/08/2024]
Abstract
The Triggering Receptor Expressed on Myeloid cells 2 (TREM-2) has been widely known by its anti-inflammatory activity. It can be activated in response to microbes and tissue damage, leading to phagocytosis, autophagy, cell polarization and migration, counter inflammation, and tissue repair. So far, the receptor has been largely explored in neurodegenerative disorders, however, a growing number of studies have been investigating its contribution in different pathological conditions, including metabolic diseases, in which (resident) macrophages play a crucial role. In this regard, TREM-2 + macrophages have been implicated in the onset and development of obesity, atherosclerosis, and fibrotic liver disease. These macrophages can be detected in the brain, white adipose tissue, liver, and vascular endothelium. In this review we discuss how different murine models have been demonstrating the ability of such cells to contribute to tissue and body homeostasis by phagocytosing cellular debris and lipid structures, besides contributing to lipid homeostasis in metabolic diseases. Therefore, understanding the role of TREM-2 in metabolic disorders is crucial to expand our current knowledge concerning their immunopathology as well as to foster the development of more targeted therapies to treat such conditions.
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Affiliation(s)
| | - Amanda de Oliveira Matos
- Institute of Tropical Pathology and Public Health, Universidade Federal de Goiás, Goiânia, Brazil.
| | | | | | - Marcelle Silva-Sales
- Institute of Tropical Pathology and Public Health, Universidade Federal de Goiás, Goiânia, Brazil.
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2
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Wang Q, Cao Y, Ye S, Ding M, Ge W, Liang Y, Chen J. Trem2/Syk/PI3K axis contributes to the host protection against Toxoplasma gondii-induced adverse pregnancy outcomes via modulating decidual macrophages. PLoS Pathog 2024; 20:e1012543. [PMID: 39250507 PMCID: PMC11412541 DOI: 10.1371/journal.ppat.1012543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 09/19/2024] [Accepted: 08/28/2024] [Indexed: 09/11/2024] Open
Abstract
Decidual macrophages residing at the maternal-fetal interface have been recognized as pivotal factors for maintaining normal pregnancy; however, they are also key target cells of Toxoplasma gondii (T. gondii) in the pathology of T. gondii-induced adverse pregnancy. Trem2, as a functional receptor on macrophage surface, recognizes and binds various kinds of pathogens. The role and underlying mechanism of Trem2 in T. gondii infection remain elusive. In the present study, we found that T. gondii infection downregulated Trem2 expression and that Trem2-/- mice exhibited more severe adverse pregnancy outcomes than wildtype mice. We also demonstrated that T. gondii infection resulted in increased decidual macrophages, which were significantly reduced in the Trem2-/- pregnant mouse model as compared to wildtype control animals. We further described the inhibited proliferation, migration, and invasion functions of trophoblast cell by T. gondii antigens through macrophages as an "intermediate bridge", while this inhibition can be rescued by Trem2 agonist HSP60. Concurrently, Trem2 deficiency in bone marrow-derived macrophages (BMDMs) heightened the inhibitory effect of TgAg on the migration and invasion of trophoblast cells, accompanied by higher pro-inflammatory factors (IL-1β, IL-6 and TNF-α) but a lower chemokine (CXCL1) in T. gondii antigens-treated BMDMs. Furthermore, compelling evidence from animal models and in vitro cell experiments suggests that T. gondii inhibits the Trem2-Syk-PI3K signaling pathway, leading to impaired function of decidual macrophages. Therefore, our findings highlight Trem2 signaling as an essential pathway by which decidual macrophages respond to T. gondii infection, suggesting Trem2 as a crucial sensor of decidual macrophages and potential therapeutic target in the pathology of T. gondii-induced adverse pregnancy.
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Affiliation(s)
- Qing Wang
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu, People’s Republic of China
| | - Yining Cao
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu, People’s Republic of China
| | - Songyi Ye
- Department of Pediatric Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, People’s Republic of China
| | - Maoyuan Ding
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu, People’s Republic of China
| | - Wenliang Ge
- Department of Pediatric Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, People’s Republic of China
| | - Yuejin Liang
- Department of Microbiology & Immunology, The University of Texas Medical Branch Galveston, Texas, United States of America
| | - Jinling Chen
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu, People’s Republic of China
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3
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Matos ADO, Dantas PHDS, Queiroz HAGDB, Silva-Sales M, Sales-Campos H. TREM-2: friend or foe in infectious diseases? Crit Rev Microbiol 2024; 50:1-19. [PMID: 36403150 DOI: 10.1080/1040841x.2022.2146481] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/07/2022] [Indexed: 11/21/2022]
Abstract
The triggering receptor expressed on myeloid cells-2 (TREM-2) is an immune receptor expressed on immune and non-immune cells, more frequently investigated in neurodegenerative disorders and considered a marker for microglia activation. In infectious diseases, the receptor was initially believed to be an anti-inflammatory molecule, opposing the inflammation triggered by TREM-1. Currently, TREM-2 is associated with different aspects in response to infectious stimuli, including the induction of bacterial phagocytosis and clearance, containment of exacerbated pro-inflammatory responses, induction of M2 differentiation and activation of Th1 lymphocytes, besides of neurological damage after viral infection. Here, we present and discuss results published in the last two decades regarding the expression, activation and functions of TREM-2 during the course of bacterial, viral, fungal and parasitic infections. A surprisingly plasticity was observed regarding the roles of the receptor in the aforementioned contexts, which largely varied according to the cell/organ and pathogen type, besides influencing disease outcome. Therefore, our review aimed to critically overview the role of TREM-2 in infectious diseases, highlighting its potential to be used as a clinical biomarker or therapeutic target.
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Affiliation(s)
| | | | | | - Marcelle Silva-Sales
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Brazil
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Lei X, Wang Y, Broens C, Borst J, Xiao Y. Immune checkpoints targeting dendritic cells for antibody-based modulation in cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 382:145-179. [PMID: 38225102 DOI: 10.1016/bs.ircmb.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Dendritic cells (DC) are professional antigen-presenting cells which link innate to adaptive immunity. DC play a central role in regulating antitumor T-cell responses in both tumor-draining lymph nodes (TDLN) and the tumor microenvironment (TME). They modulate effector T-cell responses via immune checkpoint proteins (ICPs) that can be either stimulatory or inhibitory. Functions of DC are often impaired by the suppressive TME leading to tumor immune escape. Therefore, better understanding of the mechanisms of action of ICPs expressed by (tumor-infiltrating) DC will lead to potential new treatment strategies. Genetic manipulation and high-dimensional analyses have provided insight in the interactions between DC and T-cells in TDLN and the TME upon ICP targeting. In this review, we discuss (tumor-infiltrating) DC lineage cells and tumor tissue specific "mature" DC states and their gene signatures in relation to anti-tumor immunity. We also review a number of ICPs expressed by DC regarding their functions in phagocytosis, DC activation, or inhibition and outline position in, or promise for clinical trials in cancer immunotherapy. Collectively, we highlight the critical role of DC and their exact status in the TME for the induction and propagation of T-cell immunity to cancer.
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Affiliation(s)
- Xin Lei
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Yizhi Wang
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Chayenne Broens
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Jannie Borst
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Yanling Xiao
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands.
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Han S, Li X, Xia N, Zhang Y, Yu W, Li J, Jiao C, Wang Z, Pu L. Myeloid Trem2 Dynamically Regulates the Induction and Resolution of Hepatic Ischemia-Reperfusion Injury Inflammation. Int J Mol Sci 2023; 24:ijms24076348. [PMID: 37047321 PMCID: PMC10094065 DOI: 10.3390/ijms24076348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/13/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Trem2, a transmembrane protein that is simultaneously expressed in both bone marrow-derived and embryonic-derived liver-resident macrophages, plays a complex role in liver inflammation. The unique role of myeloid Trem2 in hepatic ischemia-reperfusion (IR) injury is not precisely understood. Our study showed that in the early stage of inflammation induction after IR, Deletion of myeloid Trem2 inhibited the induction of iNOS, MCP-1, and CXCL1/2, alleviated the accumulation of neutrophils and mitochondrial damage, and simultaneously decreased ROS formation. However, when inflammatory monocyte-macrophages gradually evolved into CD11bhiLy6Clow pro-resolution macrophages through a phenotypic switch, the story of Trem2 took a turn. Myeloid Trem2 in pro-resolution macrophages promotes phagocytosis of IR-accumulated apoptotic cells by controlling Rac1-related actin polymerization, thereby actively promoting the resolution of inflammation. This effect may be exercised to regulate the Cox2/PGE2 axis by Trem2, alone or synergistically with MerTK/Arg1. Importantly, when myeloid Trem2 was over-expressed, the phenotypic transition of monocytes from a pro-inflammatory to a resolution type was accelerated, whereas knockdown of myeloid Trem2 resulted in delayed upregulation of CX3CR1. Collectively, our findings suggest that myeloid Trem2 is involved in the cascade of IR inflammation in a two-sided capacity, with complex and heterogeneous roles at different stages, not only contributing to our understanding of sterile inflammatory immunity but also to better explore the regulatory strategies and intrinsic requirements of targeting Trem2 in the event of sterile liver injury.
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Hwang M, Savarin C, Kim J, Powers J, Towne N, Oh H, Bergmann CC. Trem2 deficiency impairs recovery and phagocytosis and dysregulates myeloid gene expression during virus-induced demyelination. J Neuroinflammation 2022; 19:267. [PMID: 36333761 PMCID: PMC9635103 DOI: 10.1186/s12974-022-02629-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Background Triggering receptor expressed on myeloid cells 2 (Trem2) plays a protective role in neurodegenerative diseases. By contrast, Trem2 functions can exacerbate tissue damage during respiratory viral or liver infections. We, therefore, investigated the role of Trem2 in a viral encephalomyelitis model associated with prominent Th1 mediated antiviral immunity leading to demyelination. Methods Wild-type (WT) and Trem2 deficient (Trem2−/−) mice were infected with a sublethal glia tropic murine coronavirus (MHV–JHM) intracranially. Disease progression and survival were monitored daily. Leukocyte accumulation and pathological features including demyelination and axonal damage in spinal cords (SC) were determined by flow cytometry and tissue section immunofluorescence analysis. Expression of select inflammatory cytokines and chemokines was measured by RT-PCR and global myeloid cell gene expression in SC-derived microglia and infiltrated bone-marrow-derived macrophages (BMDM) were determined using the Nanostring nCounter platform. Results BMDM recruited to SCs in response to infection highly upregulated Trem2 mRNA compared to microglia coincident with viral control. Trem2 deficiency did not alter disease onset or severity, but impaired clinical recovery after onset of demyelination. Disease progression in Trem2−/− mice could not be attributed to altered virus control or an elevated proinflammatory response. A prominent difference was increased degenerated myelin not associated with the myeloid cell markers IBA1 and/or CD68. Gene expression profiles of SC-derived microglia and BMDM further revealed that Trem2 deficiency resulted in impaired upregulation of phagocytosis associated genes Lpl and Cd36 in microglia, but a more complex pattern in BMDM. Conclusions Trem2 deficiency during viral-induced demyelination dysregulates expression of other select genes regulating phagocytic pathways and lipid metabolism, with distinct effects on microglia and BMDM. The ultimate failure to remove damaged myelin is reminiscent of toxin or autoimmune cell-induced demyelination models and supports that Trem2 function is regulated by sensing tissue damage including a dysregulated lipid environment in very distinct inflammatory environments. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02629-1.
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Wolf EM, Fingleton B, Hasty AH. The therapeutic potential of TREM2 in cancer. Front Oncol 2022; 12:984193. [PMID: 36119485 PMCID: PMC9479103 DOI: 10.3389/fonc.2022.984193] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022] Open
Abstract
Cancer continues to be a substantial health concern and a leading cause of death in the United States and around the world. Therefore, it is important to continue to explore the potential of novel therapeutic targets and combinatorial therapies. Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor of the immunoglobulin superfamily that associates with DNAX activation protein (DAP) 12 and DAP10 to propagate signals within the cell. TREM2 has primarily been recognized for its expression on cells in the monocyte-macrophage lineage, with the majority of work focusing on microglial function in Alzheimer’s Disease. However, expansion of TREM2 research into the field of cancer has revealed that epithelial tumor cells as well as intratumoral macrophages and myeloid regulatory cells also express TREM2. In this review, we discuss evidence that TREM2 contributes to tumor suppressing or oncogenic activity when expressed by epithelial tumor cells. In addition, we discuss the immunosuppressive role of TREM2-expressing intratumoral macrophages, and the therapeutic potential of targeting TREM2 in combination with immune checkpoint therapy. Overall, the literature reveals TREM2 could be considered a novel therapeutic target for certain types of cancer.
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Affiliation(s)
- Elysa M. Wolf
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States
| | - Barbara Fingleton
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Alyssa H. Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States
- Veterans Affairs Tennessee Healthcare System, Nashville, TN, United States
- *Correspondence: Alyssa H. Hasty,
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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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Vogel A, Brunner JS, Hajto A, Sharif O, Schabbauer G. Lipid scavenging macrophages and inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159066. [PMID: 34626791 DOI: 10.1016/j.bbalip.2021.159066] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 08/18/2021] [Indexed: 12/11/2022]
Abstract
Macrophages are professional phagocytes, indispensable for maintenance of tissue homeostasis and integrity. Depending on their resident tissue, macrophages are exposed to highly diverse metabolic environments. Adapted to their niche, they can contribute to local metabolic turnover through metabolite uptake, conversion, storage and release. Disturbances in tissue homeostasis caused by infection, inflammation or damage dramatically alter the local milieu, impacting macrophage activation status and metabolism. In the case of persisting stimuli, defective macrophage responses ensue, which can promote tissue damage and disease. Especially relevant herein are disbalances in lipid rich environments, where macrophages are crucially involved in lipid uptake and turnover, preventing lipotoxicity. Lipid uptake is to a large extent facilitated by macrophage expressed scavenger receptors that are dynamically regulated and important in many metabolic diseases. Here, we review the receptors mediating lipid uptake and summarize recent findings on their role in health and disease. We further highlight the underlying pathways driving macrophage lipid acquisition and their impact on myeloid metabolic remodelling.
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Affiliation(s)
- Andrea Vogel
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Julia Stefanie Brunner
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Alexander Hajto
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Omar Sharif
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
| | - Gernot Schabbauer
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
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Wu Y, Huang S, Xiao S, He J, Lu F. Impact of Galectin-Receptor Interactions on Liver Pathology During the Erythrocytic Stage of Plasmodium berghei Malaria. Front Immunol 2021; 12:758052. [PMID: 34899708 PMCID: PMC8652201 DOI: 10.3389/fimmu.2021.758052] [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: 08/13/2021] [Accepted: 10/05/2021] [Indexed: 12/25/2022] Open
Abstract
Hepatopathy is frequently observed in patients with severe malaria but its pathogenesis remains unclear. Galectins are evolutionarily conserved glycan-binding proteins with pleiotropic roles in innate and adaptive immune responses, and exhibit pivotal roles during Plasmodium spp. infection. Here, we analyzed the impact of blockage of galectin-receptor interactions by treatment with alpha (α)-lactose on liver immunopathology during the erythrocytic stage of malaria in mice infected with Plasmodium berghei ANKA (PbANKA). Our results found that compared with PbANKA-infected mice (malarial mice), blockage of galectin-receptor interactions led to decreased host survival rate and increased peripheral blood parasitemia; exacerbated liver pathology, increased numbers of CD68+ macrophages and apoptotic cells, and increased parasite burden in the livers on days 5 and 7 post infection (p.i.) as well as increased mRNA expression levels of galectin-9 (Gal-9) and its receptor, the T cell immunoglobulin domain and mucin domain protein 3 (Tim-3), interferon (IFN)α, IFNγ, and the triggering receptor expressed on myeloid cells (TREM)-1 in the livers or spleens of PbANKA-infected mice on day 7 p.i. Observed by transmission electron microscopy, the peritoneal macrophages isolated from malarial mice with α-lactose treatment had more pseudopodia than those from malarial mice. Measured by using quantitative real-time reverse transcription-polymerase chain reaction assay, the mRNA expression levels of Gal-9, IFNα, IFNβ, IFNγ, and TREM-1 were increased in the peritoneal macrophages isolated from malarial mice with α-lactose treatment in comparison of those from malarial mice. Furthermore, significant positive correlations existed between the mRNA levels of Gal-9 and Tim-3/IFNγ/TREM-1 in both the livers and the peritoneal macrophages, and between Gal-9 and Tim-3/TREM-1 in the spleens of malarial mice; significant positive correlations existed between the mRNA levels of Gal-9 and IFNγ in the livers and between Gal-9 and IFNα in the peritoneal macrophages from malarial mice treated with α-lactose. Our data suggest a potential role of galectin-receptor interactions in limiting liver inflammatory response and parasite proliferation by down-regulating the expressions of IFNα, IFNγ, and TREM-1 during PbANKA infection.
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Affiliation(s)
- Yifan Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shiguang Huang
- School of Stomatology, Jinan University, Guangzhou, China
| | - Siyu Xiao
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jian He
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Public Experimental Teaching Center, Sun Yat-sen University, Guangzhou, China
| | - Fangli Lu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Department of Clinical Laboratory, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, China
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11
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Qiu H, Shao Z, Wen X, Jiang J, Ma Q, Wang Y, Huang L, Ding X, Zhang L. TREM2: Keeping Pace With Immune Checkpoint Inhibitors in Cancer Immunotherapy. Front Immunol 2021; 12:716710. [PMID: 34539652 PMCID: PMC8446424 DOI: 10.3389/fimmu.2021.716710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/18/2021] [Indexed: 01/21/2023] Open
Abstract
To date, immune checkpoint inhibitors have been successively approved and widely used in clinical cancer treatments, however, the overall response rates are very low and almost all cancer patients eventually progressed to drug resistance, this is mainly due to the intricate tumor microenvironment and immune escape mechanisms of cancer cells. One of the main key mechanisms leading to the evasion of immune attack is the presence of the immunosuppressive microenvironment within tumors. Recently, several studies illustrated that triggering receptor expressed on myeloid cells-2 (TREM2), a transmembrane receptor of the immunoglobulin superfamily, was a crucial pathology-induced immune signaling hub, and it played a vital negative role in antitumor immunity, such as inhibiting the proliferation of T cells. Here, we reviewed the recent advances in the study of TREM2, especially focused on its regulation of tumor-related immune signaling pathways and its role as a novel target in cancer immunotherapy.
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Affiliation(s)
- Hui Qiu
- Cancer Institute, Xuzhou Medical University, Xuzhou, China.,Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Zhiying Shao
- Cancer Institute, Xuzhou Medical University, Xuzhou, China
| | - Xin Wen
- Cancer Institute, Xuzhou Medical University, Xuzhou, China.,Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Jinghua Jiang
- Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Qinggong Ma
- Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Yan Wang
- Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Long Huang
- Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Xin Ding
- Cancer Institute, Xuzhou Medical University, Xuzhou, China.,Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Longzhen Zhang
- Cancer Institute, Xuzhou Medical University, Xuzhou, China.,Department of Radiation Oncology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
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Chua CLL, Ng IMJ, Yap BJM, Teo A. Factors influencing phagocytosis of malaria parasites: the story so far. Malar J 2021; 20:319. [PMID: 34271941 PMCID: PMC8284020 DOI: 10.1186/s12936-021-03849-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/07/2021] [Indexed: 12/16/2022] Open
Abstract
There are seven known species of Plasmodium spp. that can infect humans. The human host can mount a complex network of immunological responses to fight infection and one of these immune functions is phagocytosis. Effective and timely phagocytosis of parasites, accompanied by the activation of a regulated inflammatory response, is beneficial for parasite clearance. Functional studies have identified specific opsonins, particularly antibodies and distinct phagocyte sub-populations that are associated with clinical protection against malaria. In addition, cellular and molecular studies have enhanced the understanding of the immunological pathways and outcomes following phagocytosis of malaria parasites. In this review, an integrated view of the factors that can affect phagocytosis of infected erythrocytes and parasite components, the immunological consequences and their association with clinical protection against Plasmodium spp. infection is provided. Several red blood cell disorders and co-infections, and drugs that can influence phagocytic capability during malaria are also discussed. It is hoped that an enhanced understanding of this immunological process can benefit the design of new therapeutics and vaccines to combat this infectious disease.
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Affiliation(s)
| | - Ida May Jen Ng
- School of Biosciences, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Bryan Ju Min Yap
- School of Biosciences, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Andrew Teo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore. .,Department of Medicine, The Doherty Institute, University of Melbourne, Victoria, Australia.
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Identification of Mamu-DRB1 gene as a susceptibility factor for Entamoeba nuttalli infection in Chinese Macaca mulatta. INFECTION GENETICS AND EVOLUTION 2021; 93:104952. [PMID: 34091067 DOI: 10.1016/j.meegid.2021.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/26/2021] [Accepted: 06/01/2021] [Indexed: 11/21/2022]
Abstract
Entamoeba nuttalli infection is highly prevalent in captive and wild macaques. A recent study suggested that the genetic factor of host macaques was correlated with the genotypes of E. nuttalli isolates. This study focused on the correlation between the rhesus macaque host major histocompatibility complex gene and E. nuttalli infection. Thirty-nine stool samples were obtained from Mount Qing-ling (Guizhou Province, China). Polymerase chain reaction analysis detected the infection rate of E. nuttalli, Entamoeba coli, and Entamoeba chattoni as 69.23%, 69.23%, and 87.18%, respectively. A new Serine-rich Protein genotype was detected, and the rRNA of E. nuttalli isolates from Mount Qian-ling was completely identical to the GY4 strain. In the distance-based neighbor-joining tree, Mamu-DRB1, not Mamu-DPB or Mamu-B gene, was related to E. nuttalli infection. Mamu-DRB1 genes of rhesus macaques in Mounts Qian-ling and Long-hu were highly polymorphic, and the rhesus macaques with two major types of Mamu-DRB1 showed susceptibility to E. nuttalli infection. The Mamu-DRB1 gene analysis in this study indicated that the Mamu-DRB1 gene is an important factor that influences the susceptibility of E. nuttalli infection in Chinese Macaca mulatta. This study contributes to a better understanding of host susceptibility to Entamoeba.
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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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15
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Coelho I, Duarte N, Barros A, Macedo MP, Penha-Gonçalves C. Trem-2 Promotes Emergence of Restorative Macrophages and Endothelial Cells During Recovery From Hepatic Tissue Damage. Front Immunol 2021; 11:616044. [PMID: 33628208 PMCID: PMC7897679 DOI: 10.3389/fimmu.2020.616044] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Macrophages are pivotal in mounting liver inflammatory and tissue repair responses upon hepatic injury, showing remarkable functional plasticity. The molecular mechanisms determining macrophage transition from inflammatory to restorative phenotypes in the damaged liver remain unclear. Using mouse models of acute (APAP) and chronic (CCl4) drug-induced hepatotoxic injury we show that the immune receptor Trem-2 controls phenotypic shifts of liver macrophages and impacts endothelial cell differentiation during tissue recovery. Trem-2 gene ablation led to a delayed re-population of Kupffer cells correlating with deterred resolution of hepatic damage following acute and chronic injury. During tissue recovery, we found that macrophages transitioning to Kupffer cells expressed high levels of Trem-2. Acquisition of the transition phenotype was associated with a unique transcriptomic profile denoting strong responsiveness to oxidative stress and downmodulation of the pro-inflammatory phenotype, which was not observed in absence of Trem-2. During tissue recovery, lack of Trem-2 favored accumulation of a liver-damage associated endothelial cell population (LDECs), whose transcriptional program was compatible with endothelial de-differentiation. Accordingly, LDECs precursor potential is supported by the downregulation of surface endothelial cell markers and by striking in vitro morphological changes towards typical endothelial cells. In conclusion, we found that the dynamics of liver macrophages in response to liver injury are critically controlled by Trem-2 and this regulation is interlinked with the de-differentiation of endothelial cells and heightened liver pathology. We propose that Trem-2 promotes the transition from pro-inflammatory to tissue repair phase by driving the acquisition of restorative properties in phagocytic macrophages.
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Affiliation(s)
- Inês Coelho
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Nádia Duarte
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - André Barros
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Maria Paula Macedo
- CEDOC, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
- APDP Diabetes Portugal, Education and Research Center (APDP-ERC), Lisbon, Portugal
- Department of Medical Sciences, Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Carlos Penha-Gonçalves
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- APDP Diabetes Portugal, Education and Research Center (APDP-ERC), Lisbon, Portugal
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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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Zhu Z, Zhang X, Dong W, Wang X, He S, Zhang H, Wang X, Wei R, Chen Y, Liu X, Guo C. TREM2 suppresses the proinflammatory response to facilitate PRRSV infection via PI3K/NF-κB signaling. PLoS Pathog 2020; 16:e1008543. [PMID: 32401783 PMCID: PMC7250469 DOI: 10.1371/journal.ppat.1008543] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 05/26/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) serves as an anti-inflammatory receptor, negatively regulating the innate immune response. TREM2 is mainly expressed on dendritic cells and macrophages, the target cells of porcine reproductive and respiratory syndrome virus (PRRSV). Thus, we investigated the potential role of TREM2 in PRRSV infection in porcine alveolar macrophages (PAMs). We found that there was an increased expression of TREM2 upon PRRSV infection in vitro. TREM2 silencing restrained the replication of PRRSV, whereas TREM2 overexpression facilitated viral replication. The cytoplasmic tail domain of TREM2 interacted with PRRSV Nsp2 to promote infection. TREM2 downregulation led to early activation of PI3K/NF-κB signaling, thus reinforcing the expression of proinflammatory cytokines and type I interferons. Due to the enhanced cytokine expression, a disintegrin and metalloproteinase 17 was activated to promote the cleavage of membrane CD163, which resulted in suppression of infection. Furthermore, exogenous soluble TREM2 (sTREM2)-mediated inhibition of PRRSV attachment might be attributed to its competitive binding to viral envelope proteins. In pigs, following PRRSV challenge in vivo, the expression of TREM2 in lungs and lymph nodes as well as the production of sTREM2 were significantly increased. These novel findings indicate that TREM2 plays a role in regulating PRRSV replication via the inflammatory response. Therefore, our work describes a novel antiviral mechanism against PRRSV infection and suggests that targeting TREM2 could be a new approach in the control of the PRRSV infection.
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Affiliation(s)
- Zhenbang Zhu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Xiaoxiao Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Wenjuan Dong
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Xiaoying Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Sheng He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Hui Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Xun Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Ruiping Wei
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Yaosheng Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Xiaohong Liu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
| | - Chunhe Guo
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong, PR China
- * E-mail:
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Singh AK, Mishra G, Maurya A, Awasthi R, Kumari K, Thakur A, Rai A, Rai GK, Sharma B, Kulkarni GT, Singh SK. Role of TREM2 in Alzheimer's Disease and its Consequences on β- Amyloid, Tau and Neurofibrillary Tangles. Curr Alzheimer Res 2020; 16:1216-1229. [DOI: 10.2174/1567205016666190903102822] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/21/2019] [Accepted: 08/21/2019] [Indexed: 11/22/2022]
Abstract
:
Alzheimer's Disease (AD) is age-related neurodegenerative disorder recognized by a steadily
gradual cognitive decline that has devastating personal and socioeconomic implications. Recently, some
genetic factors for AD have been identified which attracted wide attention of researchers in different
areas of AD biology and possible new therapeutic targets. Alternative forms of triggering receptor expressed
on myeloid cells 2 (TREM2) genes are examples of such risk factors, which contribute higher
risk for developing AD. Comprehending TREM2 function pledge to provide salient insight into how
neuroinflammation contributes to AD pathology. The dearth of microglial TREM2 shepherd to augmented
tau pathology is couple with frequent enhancement of activated neuronal stress kinases. The involvement
of TREM2 in the regulation of tau-associated innate immune response of the CNS has clearly
demonstrated through these findings. However, whether decrease level of TREM2 assists pathology of
tau through changed clearance and pathological escalation of tau or through direct contact between microglia
and neuron and any alternative possible mechanisms need to examine. This review briefly summarizes
distinct functional roles of TREM2 in AD pathology and highlights the TREM2 gene regulation.
We have also addressed the impact of TREM2 on β-amyloid plaques and tau pathology in Alzheimer’s
disease.
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Affiliation(s)
- Anurag K. Singh
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
| | - Gaurav Mishra
- Department of Pharmacy, School of Chemical Sciences & Pharmacy, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer-305817, Rajasthan, India
| | - Anand Maurya
- Department of Pharmacy, School of Chemical Sciences & Pharmacy, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer-305817, Rajasthan, India
| | - Rajendra Awasthi
- Department of Pharmaceutics, Amity Institute of Pharmacy, Amity University Uttar Pradesh, Sector 125, Noida - 201303, India
| | - Komal Kumari
- Department of Pharmacy, School of Chemical Sciences & Pharmacy, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer-305817, Rajasthan, India
| | - Abhimanyu Thakur
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Arati Rai
- Hygia Institute of Pharmaceutical Education & Research, Lucknow-226020, Uttar Pradesh, India
| | - Gopal Kumar Rai
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi- 221005, Uttar Pradesh, India
| | - Bhupesh Sharma
- Department of Pharmacology, Amity Institute of Pharmacy, Amity University Uttar Pradesh, Sector 125, Noida - 201303, India
| | - Giriraj T Kulkarni
- Department of Pharmaceutics, Amity Institute of Pharmacy, Amity University Uttar Pradesh, Sector 125, Noida - 201303, India
| | - Santosh Kumar Singh
- Centre of Experimental Medicine & Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
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Circulating Monocytes, Tissue Macrophages, and Malaria. J Trop Med 2019; 2019:3720838. [PMID: 31662766 PMCID: PMC6791199 DOI: 10.1155/2019/3720838] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 07/22/2019] [Accepted: 08/06/2019] [Indexed: 12/19/2022] Open
Abstract
Malaria is a significant cause of global morbidity and mortality. The Plasmodium parasite has a complex life cycle with mosquito, liver, and blood stages. The blood stages can preferentially affect organs such as the brain and placenta. In each of these stages and organs, the parasite will encounter monocytes and tissue-specific macrophages—key cell types in the innate immune response. Interactions between the Plasmodium parasite and monocytes/macrophages lead to several changes at both cellular and molecular levels, such as cytokine release and receptor expression. In this review, we summarize current knowledge on the relationship between malaria and blood intervillous monocytes and tissue-specific macrophages of the liver (Kupffer cells), central nervous system (microglia), and placenta (maternal intervillous monocytes and fetal Hofbauer cells). We describe their potential roles in modulating outcomes from infection and areas for future investigation.
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20
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Penha-Gonçalves C. Genetics of Malaria Inflammatory Responses: A Pathogenesis Perspective. Front Immunol 2019; 10:1771. [PMID: 31417551 PMCID: PMC6682681 DOI: 10.3389/fimmu.2019.01771] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 07/15/2019] [Indexed: 12/27/2022] Open
Abstract
Despite significant progress in combating malaria in recent years the burden of severe disease and death due to Plasmodium infections remains a global public health concern. Only a fraction of infected people develops severe clinical syndromes motivating a longstanding search for genetic determinants of malaria severity. Strong genetic effects have been repeatedly ascribed to mutations and allelic variants of proteins expressed in red blood cells but the role of inflammatory response genes in disease pathogenesis has been difficult to discern. We revisited genetic evidence provided by inflammatory response genes that have been repeatedly associated to malaria, namely TNF, NOS2, IFNAR1, HMOX1, TLRs, CD36, and CD40LG. This highlighted specific genetic variants having opposing roles in the development of distinct malaria clinical outcomes and unveiled diverse levels of genetic heterogeneity that shaped the complex association landscape of inflammatory response genes with malaria. However, scrutinizing genetic effects of individual variants corroborates a pathogenesis model where pro-inflammatory genetic variants acting in early infection stages contribute to resolve infection but at later stages confer increased vulnerability to severe organ dysfunction driven by tissue inflammation. Human genetics studies are an invaluable tool to find genes and molecular pathways involved in the inflammatory response to malaria but their precise roles in disease pathogenesis are still unexploited. Genome editing in malaria experimental models and novel genotyping-by-sequencing techniques are promising approaches to delineate the relevance of inflammatory response gene variants in the natural history of infection thereby will offer new rational angles on adjuvant therapeutics for prevention and clinical management of severe malaria.
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Perugorria MJ, Esparza-Baquer A, Oakley F, Labiano I, Korosec A, Jais A, Mann J, Tiniakos D, Santos-Laso A, Arbelaiz A, Gawish R, Sampedro A, Fontanellas A, Hijona E, Jimenez-Agüero R, Esterbauer H, Stoiber D, Bujanda L, Banales JM, Knapp S, Sharif O, Mann DA. Non-parenchymal TREM-2 protects the liver from immune-mediated hepatocellular damage. Gut 2019; 68:533-546. [PMID: 29374630 PMCID: PMC6580759 DOI: 10.1136/gutjnl-2017-314107] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 12/26/2017] [Accepted: 12/28/2017] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Liver injury impacts hepatic inflammation in part via Toll-like receptor (TLR) signalling. Triggering receptor expressed on myeloid cells 2 (TREM-2) modulates TLR4-mediated inflammation in bone marrow (BM)-derived macrophages but its function in liver injury is unknown. Here we hypothesised that the anti-inflammatory effects of TREM-2 on TLR signalling may limit hepatic injury. DESIGN TREM-2 expression was analysed in livers of humans with various forms of liver injury compared with control individuals. Acute and chronic liver injury models were performed in wild type and Trem-2-/- mice. Primary liver cells from both genotypes of mice were isolated for in vitro experiments. RESULTS TREM-2 was expressed on non-parenchymal hepatic cells and induced during liver injury in mice and man. Mice lacking TREM-2 exhibited heightened liver damage and inflammation during acute and repetitive carbon tetrachloride and acetaminophen (APAP) intoxication, the latter of which TREM-2 deficiency was remarkably associated with worsened survival. Liver damage in Trem-2-/- mice following chronic injury and APAP challenge was associated with elevated hepatic lipid peroxidation and macrophage content. BM transplantation experiments and cellular reactive oxygen species assays revealed effects of TREM-2 in the context of chronic injury depended on both immune and resident TREM-2 expression. Consistent with effects of TREM-2 on inflammation-associated injury, primary hepatic macrophages and hepatic stellate cells lacking TREM-2 exhibited augmented TLR4-driven proinflammatory responses. CONCLUSION Our data indicate that by acting as a natural brake on inflammation during hepatocellular injury, TREM-2 is a critical regulator of diverse types of hepatotoxic injury.
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Affiliation(s)
- Maria J Perugorria
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- CIBERehd, Instituto de Salud Carlos III, San Sebastián, Spain
| | - Aitor Esparza-Baquer
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Fiona Oakley
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ibone Labiano
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Ana Korosec
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Alexander Jais
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Jelena Mann
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Dina Tiniakos
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Alvaro Santos-Laso
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Ander Arbelaiz
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Riem Gawish
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Ana Sampedro
- Hepatology Programme, CIMA, University of Navarra, Pamplona, Spain
| | | | - Elizabeth Hijona
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
- CIBERehd, Instituto de Salud Carlos III, San Sebastián, Spain
| | - Raul Jimenez-Agüero
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Dagmar Stoiber
- Institute of Pharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Luis Bujanda
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
- CIBERehd, Instituto de Salud Carlos III, San Sebastián, Spain
| | - Jesus María Banales
- Department of Liver and Gastrointestinal Diseases, Biodonostia Research Institute, Donostia University Hospital, University of the Basque Country (UPV-EHU), San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- CIBERehd, Instituto de Salud Carlos III, San Sebastián, Spain
| | - Sylvia Knapp
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Omar Sharif
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, Austria
| | - Derek A Mann
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
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22
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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: 286] [Impact Index Per Article: 47.7] [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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23
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Huang HM, McMorran BJ, Foote SJ, Burgio G. Host genetics in malaria: lessons from mouse studies. Mamm Genome 2018; 29:507-522. [PMID: 29594458 DOI: 10.1007/s00335-018-9744-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 03/22/2018] [Indexed: 01/09/2023]
Abstract
Malaria remains a deadly parasitic disease caused by Plasmodium, claiming almost half a million lives every year. While parasite genetics and biology are often the major targets in many studies, it is becoming more evident that host genetics plays a crucial role in the outcome of the infection. Similarly, Plasmodium infections in mice also rely heavily on the genetic background of the mice, and often correlate with observations in human studies, due to their high genetic homology with humans. As such, murine models of malaria are a useful tool for understanding host responses during Plasmodium infections, as well as dissecting host-parasite interactions through various genetic manipulation techniques. Reverse genetic approach such as quantitative trait loci studies and random mutagenesis screens have been employed to discover novel host genes that affect malaria susceptibility in mouse models, while other targeted studies utilize mouse models to validate observation from human studies. Herein, we review the findings from the past and present studies on murine models of hepatic and erythrocytic stages of malaria and speculate on how the current mouse models benefit from the recent development in CRISPR/Cas9 gene editing technology.
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Affiliation(s)
- Hong Ming Huang
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Canberra, ACT, 2601, Australia
| | - Brendan J McMorran
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Canberra, ACT, 2601, Australia
| | - Simon J Foote
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Canberra, ACT, 2601, Australia
| | - Gaetan Burgio
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Canberra, ACT, 2601, Australia.
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Raha AA, Henderson JW, Stott SRW, Vuono R, Foscarin S, Friedland RP, Zaman SH, Raha-Chowdhury R. Neuroprotective Effect of TREM-2 in Aging and Alzheimer's Disease Model. J Alzheimers Dis 2018; 55:199-217. [PMID: 27662313 DOI: 10.3233/jad-160663] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neuroinflammation and activation of innate immunity are early events in neurodegenerative diseases including Alzheimer's disease (AD). Recently, a rare mutation in the gene Triggering receptor expressed on myeloid cells 2 (TREM2) has been associated with a substantial increase in the risk of developing late onset AD. To uncover the molecular mechanisms underlying this association, we investigated the RNA and protein expression of TREM2 in APP/PS1 transgenic mice. Our findings suggest that TREM2 not only plays a critical role in inflammation, but is also involved in neuronal cell survival and in neurogenesis. We have shown that TREM2 is a soluble protein transported by macrophages through ventricle walls and choroid plexus, and then enters the brain parenchyma via radial glial cells. TREM2 protein is essential for neuroplasticity and myelination. During the late stages of life, a lack of TREM2 protein may accelerate aging processes and neuronal cell loss and reduce microglial activity, ultimately leading to neuroinflammation. As inflammation plays a major role in neurodegenerative diseases, a lack of TREM2 could be a missing link between immunomodulation and neuroprotection.
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Affiliation(s)
- Animesh Alexander Raha
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - James W Henderson
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Simon R W Stott
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Romina Vuono
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Simona Foscarin
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | | | - Shahid H Zaman
- Cambridge Intellectual & Developmental Disabilities Research Group, Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Ruma Raha-Chowdhury
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
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25
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The lipid-sensor TREM2 aggravates disease in a model of LCMV-induced hepatitis. Sci Rep 2017; 7:11289. [PMID: 28900132 PMCID: PMC5595927 DOI: 10.1038/s41598-017-10637-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 08/14/2017] [Indexed: 12/20/2022] Open
Abstract
Lipid metabolism is increasingly being appreciated to affect immunoregulation, inflammation and pathology. In this study we found that mice infected with lymphocytic choriomeningitis virus (LCMV) exhibit global perturbations of circulating serum lipids. Mice lacking the lipid-sensing surface receptor triggering receptor expressed on myeloid cells 2 (Trem2 -/-) were protected from LCMV-induced hepatitis and showed improved virus control despite comparable virus-specific T cell responses. Non-hematopoietic expression of TREM2 was found to be responsible for aggravated hepatitis, indicating a novel role for TREM2 in the non-myeloid compartment. These results suggest a link between virus-perturbed lipids and TREM2 that modulates liver pathogenesis upon viral infection. Targeted interventions of this immunoregulatory axis may ameliorate tissue pathology in hepatitis.
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26
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Jay TR, von Saucken VE, Landreth GE. TREM2 in Neurodegenerative Diseases. Mol Neurodegener 2017; 12:56. [PMID: 28768545 PMCID: PMC5541421 DOI: 10.1186/s13024-017-0197-5] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/20/2017] [Indexed: 12/12/2022] Open
Abstract
TREM2 variants have been identified as risk factors for Alzheimer's disease (AD) and other neurodegenerative diseases (NDDs). Because TREM2 encodes a receptor exclusively expressed on immune cells, identification of these variants conclusively demonstrates that the immune response can play an active role in the pathogenesis of NDDs. These TREM2 variants also confer the highest risk for developing Alzheimer's disease of any risk factor identified in nearly two decades, suggesting that understanding more about TREM2 function could provide key insights into NDD pathology and provide avenues for novel immune-related NDD biomarkers and therapeutics. The expression, signaling and function of TREM2 in NDDs have been extensively investigated in an effort to understand the role of immune function in disease pathogenesis and progression. We provide a comprehensive review of our current understanding of TREM2 biology, including new insights into the regulation of TREM2 expression, and TREM2 signaling and function across NDDs. While many open questions remain, the current body of literature provides clarity on several issues. While it is still often cited that TREM2 expression is decreased by pro-inflammatory stimuli, it is now clear that this is true in vitro, but inflammatory stimuli in vivo almost universally increase TREM2 expression. Likewise, while TREM2 function is classically described as promoting an anti-inflammatory phenotype, more than half of published studies demonstrate a pro-inflammatory role for TREM2, suggesting that its role in inflammation is much more complex. Finally, these components of TREM2 biology are applied to a discussion of how TREM2 impacts NDD pathologies and the latest assessment of how these findings might be applied to immune-directed clinical biomarkers and therapeutics.
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Affiliation(s)
- Taylor R. Jay
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
| | - Victoria E. von Saucken
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
| | - Gary E. Landreth
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
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27
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Yeh FL, Hansen DV, Sheng M. TREM2, Microglia, and Neurodegenerative Diseases. Trends Mol Med 2017; 23:512-533. [DOI: 10.1016/j.molmed.2017.03.008] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 02/15/2017] [Accepted: 03/26/2017] [Indexed: 01/17/2023]
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28
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Gonçalves LA, Rodo J, Rodrigues-Duarte L, de Moraes LV, Penha-Gonçalves C. HGF Secreted by Activated Kupffer Cells Induces Apoptosis of Plasmodium-Infected Hepatocytes. Front Immunol 2017; 8:90. [PMID: 28220125 PMCID: PMC5292919 DOI: 10.3389/fimmu.2017.00090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 01/19/2017] [Indexed: 02/03/2023] Open
Abstract
Malaria liver stage infection is an obligatory parasite development step and represents a population bottleneck in Plasmodium infections, providing an advantageous target for blocking parasite cycle progression. Parasite development inside hepatocytes implies a gross cellular insult evoking innate host responses to counteract intra-hepatocytic infection. Using primary hepatocyte cultures, we investigated the role of Kupffer cell-derived hepatocyte growth factor (HGF) in malaria liver stage infection. We found that Kupffer cells from Plasmodium-infected livers produced high levels of HGF, which trigger apoptosis of infected hepatocytes through a mitochondrial-independent apoptosis pathway. HGF action in infected hepatocyte primary cultures results in a potent reduction of parasite yield by specifically sensitizing hepatocytes carrying established parasite exo-erythrocytic forms to undergo apoptosis. This apoptosis mechanism is distinct from cell death that is spontaneously induced in infected cultures and is governed by Fas signaling modulation through a mitochondrial-dependent apoptosis pathway. This work indicates that HGF and Fas signaling pathways are part of an orchestrated host apoptosis response that occurs during malaria liver stage infection, decreasing the success of infection of individual hepatocytes. Our results raise the hypothesis that paracrine signals derived from Kupffer cell activation are implicated in directing death of hepatocytes infected with the malaria parasite.
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Affiliation(s)
| | - Joana Rodo
- Instituto Gulbenkian de Ciência , Oeiras , Portugal
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29
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Susceptibility to Plasmodium yoelii preerythrocytic infection in BALB/c substrains is determined at the point of hepatocyte invasion. Infect Immun 2014; 83:39-47. [PMID: 25312960 DOI: 10.1128/iai.02230-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
After transmission by Anopheles mosquitoes, Plasmodium sporozoites travel to the liver, infect hepatocytes, and rapidly develop as intrahepatocytic liver stages (LS). Rodent models of malaria exhibit large differences in the magnitude of liver infection, both between parasite species and between strains of mice. This has been mainly attributed to differences in innate immune responses and parasite infectivity. Here, we report that BALB/cByJ mice are more susceptible to Plasmodium yoelii preerythrocytic infection than BALB/cJ mice. This difference occurs at the level of early hepatocyte infection, but expression levels of reported host factors that are involved in infection do not correlate with susceptibility. Interestingly, BALB/cByJ hepatocytes are more frequently polyploid; thus, their susceptibility converges on the previously observed preference of sporozoites to infect polyploid hepatocytes. Gene expression analysis demonstrates hepatocyte-specific differences in mRNA abundance for numerous genes between BALB/cByJ and BALB/cJ mice, some of which encode hepatocyte surface molecules. These data suggest that a yet-unknown receptor for sporozoite infection, present at elevated levels on BALB/cByJ hepatocytes and also polyploid hepatocytes, might facilitate Plasmodium liver infection.
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30
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Gun SY, Claser C, Tan KSW, Rénia L. Interferons and interferon regulatory factors in malaria. Mediators Inflamm 2014; 2014:243713. [PMID: 25157202 PMCID: PMC4124246 DOI: 10.1155/2014/243713] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 06/18/2014] [Indexed: 12/29/2022] Open
Abstract
Malaria is one of the most serious infectious diseases in humans and responsible for approximately 500 million clinical cases and 500 thousand deaths annually. Acquired adaptive immune responses control parasite replication and infection-induced pathologies. Most infections are clinically silent which reflects on the ability of adaptive immune mechanisms to prevent the disease. However, a minority of these can become severe and life-threatening, manifesting a range of overlapping syndromes of complex origins which could be induced by uncontrolled immune responses. Major players of the innate and adaptive responses are interferons. Here, we review their roles and the signaling pathways involved in their production and protection against infection and induced immunopathologies.
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Affiliation(s)
- Sin Yee Gun
- Singapore Immunology Network, Agency for Science, Technology and Research (ASTAR), Singapore 138648
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Carla Claser
- Singapore Immunology Network, Agency for Science, Technology and Research (ASTAR), Singapore 138648
| | - Kevin Shyong Wei Tan
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Laurent Rénia
- Singapore Immunology Network, Agency for Science, Technology and Research (ASTAR), Singapore 138648
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
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31
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Kupffer Cells in Health and Disease. MACROPHAGES: BIOLOGY AND ROLE IN THE PATHOLOGY OF DISEASES 2014. [PMCID: PMC7121975 DOI: 10.1007/978-1-4939-1311-4_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Kupffer cells (KC), the resident macrophages of the liver, represent the largest population of mononuclear phagocytes in the body. Phenotypic, developmental, and functional aspects of these cells in steady state and in different diseases are the focus of this review. Recently it has become evident that KC precursors seed the liver already early in fetal development, and the population can be maintained independently from circulating monocytes. However, inflammatory conditions allow rapid differentiation of monocytes into mature cells that are indistinguishable from genuine KC. KC are located in the lumen of sinusoids that receive blood both from the portal vein, carrying nutrients and microbial products from the gut, and from the hepatic artery. This positions KC ideally for their prime function, namely surveillance and clearance of the circulation. As such, they are important in iron recycling by phagocytosing effete erythrocytes, for instance. The immunophenotype of KC, characterized by a wide variety of endocytic receptors, is indicative of this scavenger function. In maintaining homeostasis, KC have an ambivalent response to exogenous triggers. On the one hand, their surveillance function requires alert responses to potentially hazardous substances. On the other hand, continuous exposure of the cells to the trigger-rich content of blood originating from the gut dampens their responsiveness to further stimuli. This ambivalence is also reflected in their diverse roles in disease pathogenesis. For the latter, we sketch the contribution of KC by giving examples of their role in metabolic disease, infections, and liver injury.
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