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Longo Y, Mascaraque SM, Andreacchio G, Werner J, Katahira I, De Marchi E, Pegoraro A, Lebbink RJ, Köhrer K, Petzsch P, Tao R, Di Virgilio F, Adinolfi E, Drexler I. The purinergic receptor P2X7 as a modulator of viral vector-mediated antigen cross-presentation. Front Immunol 2024; 15:1360140. [PMID: 38711513 PMCID: PMC11070468 DOI: 10.3389/fimmu.2024.1360140] [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: 12/22/2023] [Accepted: 04/05/2024] [Indexed: 05/08/2024] Open
Abstract
Introduction Modified Vaccinia Virus Ankara (MVA) is a safe vaccine vector inducing long- lasting and potent immune responses. MVA-mediated CD8+T cell responses are optimally induced, if both, direct- and cross-presentation of viral or recombinant antigens by dendritic cells are contributing. Methods To improve the adaptive immune responses, we investigated the role of the purinergic receptor P2X7 (P2RX7) in MVA-infected feeder cells as a modulator of cross-presentation by non-infected dendritic cells. The infected feeder cells serve as source of antigen and provide signals that help to attract dendritic cells for antigen take up and to license these cells for cross-presentation. Results We demonstrate that presence of an active P2RX7 in major histocompatibility complex (MHC) class I (MHCI) mismatched feeder cells significantly enhanced MVA-mediated antigen cross-presentation. This was partly regulated by P2RX7-specific processes, such as the increased availability of extracellular particles as well as the altered cellular energy metabolism by mitochondria in the feeder cells. Furthermore, functional P2RX7 in feeder cells resulted in a delayed but also prolonged antigen expression after infection. Discussion We conclude that a combination of the above mentioned P2RX7-depending processes leads to significantly increased T cell activation via cross- presentation of MVA-derived antigens. To this day, P2RX7 has been mostly investigated in regards to neuroinflammatory diseases and cancer progression. However, we report for the first time the crucial role of P2RX7 for antigen- specific T cell immunity in a viral infection model.
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Affiliation(s)
- Ylenia Longo
- Institute of Virology, Universitätsklinikum Düsseldorf, Düsselorf, Germany
| | | | | | - Julia Werner
- Institute of Molecular Medicine II, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Ichiro Katahira
- Institute of Molecular Medicine II, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Elena De Marchi
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Anna Pegoraro
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Robert Jan Lebbink
- Institute of Infection Immunity, University of Utrecht, Utrecht, Netherlands
| | - Karl Köhrer
- Biological and Medical Research Center (BMFZ), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Patrick Petzsch
- Biological and Medical Research Center (BMFZ), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Ronny Tao
- Institute of Virology, Universitätsklinikum Düsseldorf, Düsselorf, Germany
| | | | - Elena Adinolfi
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Ingo Drexler
- Institute of Virology, Universitätsklinikum Düsseldorf, Düsselorf, Germany
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2
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Acuña-Castillo C, Escobar A, García-Gómez M, Bachelet VC, Huidobro-Toro JP, Sauma D, Barrera-Avalos C. P2X7 Receptor in Dendritic Cells and Macrophages: Implications in Antigen Presentation and T Lymphocyte Activation. Int J Mol Sci 2024; 25:2495. [PMID: 38473744 DOI: 10.3390/ijms25052495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/15/2024] [Accepted: 01/24/2024] [Indexed: 03/14/2024] Open
Abstract
The P2X7 receptor, a member of the P2X purinergic receptor family, is a non-selective ion channel. Over the years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation has captured the scientific community's attention. This function is essential for the immune system to identify and respond to external threats, such as pathogens and tumor cells, through T lymphocytes. New studies show that the P2X7 receptor is crucial for controlling how antigens are presented and how T cells are activated. These studies focus on antigen-presenting cells, like dendritic cells and macrophages. This review examines how the P2X7 receptor interferes with effective antigen presentation and activates T cells and discusses the fundamental mechanisms that can affect the immune response. Understanding these P2X7-mediated processes in great detail opens up exciting opportunities to create new immunological therapies.
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Affiliation(s)
- Claudio Acuña-Castillo
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Alejandro Escobar
- Laboratorio Biología Celular y Molecular, Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago 8380000, Chile
| | - Moira García-Gómez
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Vivienne C Bachelet
- Escuela de Medicina, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Juan Pablo Huidobro-Toro
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Daniela Sauma
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
- Centro Ciencia & Vida, Av. Del Valle Norte 725, Huechuraba 8580000, Chile
| | - Carlos Barrera-Avalos
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
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3
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Ai Y, Wang H, Liu L, Qi Y, Tang S, Tang J, Chen N. Purine and purinergic receptors in health and disease. MedComm (Beijing) 2023; 4:e359. [PMID: 37692109 PMCID: PMC10484181 DOI: 10.1002/mco2.359] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
Purines and purinergic receptors are widely distributed throughout the human body. Purine molecules within cells play crucial roles in regulating energy metabolism and other cellular processes, while extracellular purines transmit signals through specific purinergic receptors. The ubiquitous purinergic signaling maintains normal neural excitability, digestion and absorption, respiratory movement, and other complex physiological activities, and participates in cell proliferation, differentiation, migration, and death. Pathological dysregulation of purinergic signaling can result in the development of various diseases, including neurodegeneration, inflammatory reactions, and malignant tumors. The dysregulation or dysfunction of purines and purinergic receptors has been demonstrated to be closely associated with tumor progression. Compared with other subtypes of purinergic receptors, the P2X7 receptor (P2X7R) exhibits distinct characteristics (i.e., a low affinity for ATP, dual functionality upon activation, the mediation of ion channels, and nonselective pores formation) and is considered a promising target for antitumor therapy, particularly in patients with poor response to immunotherapy This review summarizes the physiological and pathological significance of purinergic signaling and purinergic receptors, analyzes their complex relationship with tumors, and proposes potential antitumor immunotherapy strategies from tumor P2X7R inhibition, tumor P2X7R overactivation, and host P2X7R activation. This review provides a reference for clinical immunotherapy and mechanism investigation.
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Affiliation(s)
- Yanling Ai
- Department of OncologyHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Hengyi Wang
- Department of Infectious DiseasesHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Lu Liu
- School of PharmacyChengdu University of Traditional Chinese MedicineChengduChina
| | - Yulin Qi
- Department of OphthalmologyThe First Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou University of Chinese MedicineGuangzhouChina
- Postdoctoral Research Station of Guangzhou University of Chinese MedicineGuangzhouChina
| | - Shiyun Tang
- Hospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Jianyuan Tang
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan ProvinceHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Nianzhi Chen
- State Key Laboratory of Ultrasound in Medicine and EngineeringCollege of Biomedical EngineeringChongqing Medical UniversityChongqingChina
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4
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Alberto AVP, Ferreira NCDS, Bonavita AGC, Nihei OK, de Farias FP, Bisaggio RDC, de Albuquerque C, Savino W, Coutinho‐Silva R, Persechini PM, Alves LA. Physiologic roles of P2 receptors in leukocytes. J Leukoc Biol 2022; 112:983-1012. [PMID: 35837975 PMCID: PMC9796137 DOI: 10.1002/jlb.2ru0421-226rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/13/2022] [Indexed: 01/01/2023] Open
Abstract
Since their discovery in the 1970s, purinergic receptors have been shown to play key roles in a wide variety of biologic systems and cell types. In the immune system, purinergic receptors participate in innate immunity and in the modulation of the adaptive immune response. In particular, P2 receptors, which respond to extracellular nucleotides, are widely expressed on leukocytes, causing the release of cytokines and chemokines and the formation of inflammatory mediators, and inducing phagocytosis, degranulation, and cell death. The activity of these receptors is regulated by ectonucleotidases-expressed in these same cell types-which regulate the availability of nucleotides in the extracellular environment. In this article, we review the characteristics of the main purinergic receptor subtypes present in the immune system, focusing on the P2 family. In addition, we describe the physiologic roles of the P2 receptors already identified in leukocytes and how they can positively or negatively modulate the development of infectious diseases, inflammation, and pain.
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Affiliation(s)
- Anael Viana Pinto Alberto
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| | | | | | - Oscar Kenji Nihei
- Center of Education and LetterState University of the West of ParanáFoz do IguaçuPRBrazil
| | | | - Rodrigo da Cunha Bisaggio
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Federal Institute of Education, Science, and Technology of Rio de JaneiroRio de JaneiroRJBrazil
| | | | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Brazilian National Institute of Science and Technology on NeuroimmunomodulationRio de Janeiro Research Network on NeuroinflammationRio de JaneiroRJBrazil
| | - Robson Coutinho‐Silva
- Laboratory of Immunophysiology, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Muanis Persechini
- Laboratory of Immunobiophysics, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Luiz Anastacio Alves
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
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Reinmuth L, Hsiao CC, Hamann J, Rosenkilde M, Mackrill J. Multiple Targets for Oxysterols in Their Regulation of the Immune System. Cells 2021; 10:cells10082078. [PMID: 34440846 PMCID: PMC8391951 DOI: 10.3390/cells10082078] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/05/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
Oxysterols, or cholesterol oxidation products, are naturally occurring lipids which regulate the physiology of cells, including those of the immune system. In contrast to effects that are mediated through nuclear receptors or by epigenetic mechanism, which take tens of minutes to occur, changes in the activities of cell-surface receptors caused by oxysterols can be extremely rapid, often taking place within subsecond timescales. Such cell-surface receptor effects of oxysterols allow for the regulation of fast cellular processes, such as motility, secretion and endocytosis. These cellular processes play critical roles in both the innate and adaptive immune systems. This review will survey the two broad classes of cell-surface receptors for oxysterols (G-protein coupled receptors (GPCRs) and ion channels), the mechanisms by which cholesterol oxidation products act on them, and their presence and functions in the different cell types of the immune system. Overall, this review will highlight the potential of oxysterols, synthetic derivatives and their receptors for physiological and therapeutic modulation of the immune system.
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Affiliation(s)
- Lisa Reinmuth
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark;
| | - Cheng-Chih Hsiao
- Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; (C.-C.H.); (J.H.)
- Neuroimmunology Research Group, The Netherlands Institute for Neuroscience, 1105BA Amsterdam, The Netherlands
| | - Jörg Hamann
- Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; (C.-C.H.); (J.H.)
- Neuroimmunology Research Group, The Netherlands Institute for Neuroscience, 1105BA Amsterdam, The Netherlands
| | - Mette Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark;
- Correspondence: (M.R.); (J.M.); Tel.: +353-(0)21-490-1400 (J.M.)
| | - John Mackrill
- Department of Physiology, School of Medicine, BioSciences Institute, University College Cork, College Road, Cork T12 YT20, Ireland
- Correspondence: (M.R.); (J.M.); Tel.: +353-(0)21-490-1400 (J.M.)
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6
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Pupovac A, Sluyter R. Roles of extracellular nucleotides and P2 receptors in ectodomain shedding. Cell Mol Life Sci 2016; 73:4159-4173. [PMID: 27180276 PMCID: PMC11108277 DOI: 10.1007/s00018-016-2274-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/10/2016] [Indexed: 02/03/2023]
Abstract
Ectodomain shedding of integral membrane receptors results in the release of soluble molecules and modification of the transmembrane portions to mediate or modulate extracellular and intracellular signalling. Ectodomain shedding is stimulated by a variety of mechanisms, including the activation of P2 receptors by extracellular nucleotides. This review describes in detail the roles of extracellular nucleotides and P2 receptors in the shedding of various cell surface molecules, including amyloid precursor protein, CD23, CD62L, and members of the epidermal growth factor, immunoglobulin and tumour necrosis factor families. This review discusses the mechanisms involved in P2 receptor-mediated shedding, demonstrating central roles for the P2 receptors, P2X7 and P2Y2, and the sheddases, ADAM10 and ADAM17, in this process in a number of cell types.
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Affiliation(s)
- Aleta Pupovac
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
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7
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Torres-Fuentes JL, Rios M, Moreno RD. Involvement of a P2X7 Receptor in the Acrosome Reaction Induced by ATP in Rat Spermatozoa. J Cell Physiol 2015; 230:3068-75. [PMID: 25989529 DOI: 10.1002/jcp.25044] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 05/11/2015] [Indexed: 02/06/2023]
Abstract
The acrosome reaction (AR) is the exocytosis of the acrosomal vesicle in response to different physiological and non-physiological stimuli. Particularly in mammals, the AR is needed for sperm to fuse with the oocyte plasma membrane, and it occurs only in capacitated sperm. Previous evidence in the literature indicates that extracellular ATP induces the AR in capacitated human and bovine spermatozoa, but its receptor has not yet been identified. The aim of this work was to define a putative ATP receptor in rat spermatozoa using pharmacological and biochemical approaches. We found that ATP induced the AR only in capacitated rat spermatozoa, which was inhibited in the presence of two general inhibitors of ATP receptors (P2 receptors), Suramin, and oxidized ATP (oATP), and one inhibitor of P2X receptor (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid [PPADS]). In addition, the AR induced by ATP in capacitated rat spermatozoa was inhibited by brilliant blue-G (BB-G) and 17-β-oestradiol, two blockers of P2X7 receptors. Moreover, the ATP analog 2'(3')-O-(4-benzoylbenzoyl) ATP (BzATP) was almost 500 times more potent than ATP to induce the AR, which agrees with the pharmacology of a P2X7 receptor. Here, we show the presence of P2X7 receptor by Western blot and its localization in the tail and acrosome by indirect immunofluorescence. Finally, we quantify the presence of ATP in the rat oviduct during the estrous cycle. We found that the ATP concentration within the lumen of the oviduct is similar to those required to induce acrosome reaction, which agree with its role during in vivo fertilization. Therefore, our results strongly suggest that ATP induces the AR in capacitated rat spermatozoa through a P2X7 receptor, which may be functional during in vivo fertilization.
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Affiliation(s)
- Jorge L Torres-Fuentes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mariana Rios
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ricardo D Moreno
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Toki Y, Takenouchi T, Harada H, Tanuma SI, Kitani H, Kojima S, Tsukimoto M. Extracellular ATP induces P2X7 receptor activation in mouse Kupffer cells, leading to release of IL-1β, HMGB1, and PGE2, decreased MHC class I expression and necrotic cell death. Biochem Biophys Res Commun 2015; 458:771-6. [PMID: 25681768 DOI: 10.1016/j.bbrc.2015.02.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 02/03/2015] [Indexed: 01/14/2023]
Abstract
Kupffer cells, which are resident macrophages in liver, can produce various cytokines and chemokines that induce hepatitis and liver fibrosis. It is suggested that extracellular ATP-induced activation of macrophage P2X7 receptor plays an important role in inflammation via release of pro-inflammatory mediators, but the role of P2X7 receptor in Kupffer cells remains unclear. Here, we show that activation of P2X7 receptor in Kupffer cells causes multiple inflammatory responses, using the clonal mouse Kupffer cell line (KUP5) that we previously established. Treatment of LPS-primed Kupffer cells with 3 mM ATP induced Ca(2+) influx, non-selective large pore formation, activation of MAPK, cell lysis, IL-1β release, prostaglandin E2 (PGE2) release, high mobility group box1 (HMGB1) release, and major histocompatibility complex (MHC) class I shedding. These events were significantly suppressed by pretreatment with P2X7 antagonist A438079, indicating involvement of P2X7 receptor activation in these inflammatory responses. Our results suggest that extracellular ATP-induced activation of P2X7 receptor of Kupffer cells plays multiple roles in the inflammatory response in liver. P2X7 receptor might be a new therapeutic target for treatment of liver diseases.
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Affiliation(s)
- Yusuke Toki
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan; Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Takato Takenouchi
- Animal Immune and Cell Biology Research Unit, Division of Animal Sciences, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Hitoshi Harada
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, 3500-3 Minamitamagaki-cho, Suzuka-shi, Mie, Japan
| | - Sei-ichi Tanuma
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Hiroshi Kitani
- Animal Immune and Cell Biology Research Unit, Division of Animal Sciences, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Shuji Kojima
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan
| | - Mitsutoshi Tsukimoto
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan.
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Desai BN, Leitinger N. Purinergic and calcium signaling in macrophage function and plasticity. Front Immunol 2014; 5:580. [PMID: 25505897 PMCID: PMC4245916 DOI: 10.3389/fimmu.2014.00580] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 10/29/2014] [Indexed: 12/30/2022] Open
Abstract
In addition to a fundamental role in cellular bioenergetics, the purine nucleotide adenosine triphosphate (ATP) plays a crucial role in the extracellular space as a signaling molecule. ATP and its metabolites serve as ligands for a family of receptors that are collectively referred to as purinergic receptors. These receptors were first described and characterized in the nervous system but it soon became evident that they are expressed ubiquitously. In the immune system, purinergic signals regulate the migration and activation of immune cells and they may also orchestrate the resolution of inflammation (1, 2). The intracellular signal transduction initiated by purinergic receptors is strongly coupled to Ca(2+)-signaling, and co-ordination of these pathways plays a critical role in innate immunity. In this review, we provide an overview of purinergic and Ca(2+)-signaling in the context of macrophage phenotypic polarization and discuss the implications on macrophage function in physiological and pathological conditions.
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Affiliation(s)
- Bimal N Desai
- Department of Pharmacology, University of Virginia , Charlottesville, VA , USA
| | - Norbert Leitinger
- Department of Pharmacology, University of Virginia , Charlottesville, VA , USA
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10
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The role of soluble fibrinogen-like protein 2 in transplantation: protection or damage. Transplantation 2014; 97:1201-6. [PMID: 24717224 DOI: 10.1097/tp.0000000000000116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Soluble fibrinogen-like protein 2 (sFGL2) is the soluble form of fibrinogen like protein 2. As a novel immunoregulatory molecule, sFGL2 is secreted mainly by T cells, especially regulatory T cells, and exerts an immunoregulatory property rather than a prothrombinase function in the immune system. sFGL2 changes not only the proliferation and differentiation of T cells but also the maturation of antigen presenting cells. Besides its innate and adaptive immunoregulatory functions, sFGL2 also induces apoptosis in cells including renal tubular epithelial cells through Fcγ receptors (FcγRs). It may affect transplantation via regulation of immunity and induction of apoptosis of different cells in a spatiotemporal manner. Here, we review the research progresses on sFGL2 including its structure, functions, and molecular mechanisms via which sFGL2 might affect organ transplantation, as well as discuss its characteristics and potential of becoming a therapeutic target in patients with rejection.
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