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Mazalo JK, Tay SS, Kempe D, Biro M. Chemokine receptor distribution on the surface of repolarizing T cells. Biophys J 2024:S0006-3495(24)00100-0. [PMID: 38327056 DOI: 10.1016/j.bpj.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/17/2023] [Accepted: 02/02/2024] [Indexed: 02/09/2024] Open
Abstract
T cells migrate constitutively with a polarized morphology, underpinned by signaling compartmentalization and discrete cytoskeletal organizations, giving rise to a dynamic and expansive leading edge, distinct from the stable and constricted uropod at the rear. In vivo, the motion and function of T cells at various stages of differentiation is highly directed by chemokine gradients. When cognate ligands bind chemokine receptors on their surface, T cells respond by reorientating their polarity axis and migrating toward the source of the chemokine signal. Despite the significance of such chemotactic repolarization to the accurate navigation and function of T cells, the precise signaling mechanisms that underlie it remain elusive. Notably, it remained unclear whether the distribution of chemokine receptors on the T cell surface is altered during repolarization. Here, we developed parallel cell-secreted and microfluidics-based chemokine gradient delivery methods and employed both fixed imaging and live lattice light-sheet microscopy to investigate the dynamics of chemokine receptor CCR5 on the surface of primary murine CD8+ T cells. Our findings show that, during constitutive migration, chemokine receptor distribution is largely isotropic on the T cell surface. However, upon exposure to a CCL3 gradient, surface chemokine receptor distributions exhibit a transient bias toward the uropod. The chemokine receptors then progressively redistribute from the uropod to cover the T cell surface uniformly. This study sheds new light on the dynamics of surface chemokine receptor distribution during T cell repolarization, advancing our understanding of the signaling of immune cells in the complex chemokine landscapes they navigate.
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Affiliation(s)
- Jessica K Mazalo
- EMBL Australia, Single Molecule Science Node, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Szun S Tay
- EMBL Australia, Single Molecule Science Node, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Daryan Kempe
- EMBL Australia, Single Molecule Science Node, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia.
| | - Maté Biro
- EMBL Australia, Single Molecule Science Node, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia.
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Zhang X, Falagan-Lotsch P, Murphy CJ. Nanoparticles Interfere with Chemotaxis: An Example of Nanoparticles as Molecular "Knockouts" at the Cellular Level. ACS NANO 2021; 15:8813-8825. [PMID: 33886273 DOI: 10.1021/acsnano.1c01262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Engineered colloidal nanoparticles show great promise in biomedical applications. While much of the work of assessing nanoparticle impact on living systems has been focused on the direct interactions of nanoparticles with cells/organisms, indirect effects via the extracellular matrix have been observed and may provide deeper insight into nanoparticle fate and effects in living systems. In particular, the large surface area of colloidal nanoparticles may sequester molecules from the biological milieu, make these molecules less bioavailable, and therefore function indirectly as "molecular knockouts" to exert effects at the cellular level and beyond. In this paper, the hypothesis that molecules that control cellular behavior (in this case, chemoattract molecules that promote migration of a human monocytic cell line, THP-1) will be less bioavailable in the presence of appropriately functionalized nanoparticles, and therefore the cellular behavior will be altered, was investigated. Three-dimensional chemotaxis assays for the characterization and comparison of THP-1 cell migration upon exposure to a gradient of monocyte chemoattractant protein-1 (MCP-1), with and without gold nanoparticles with four different surface chemistries, were performed. By time-lapse microscopy, characteristic parameters for chemotaxis, along with velocity and directionality of the cells, were quantified. Anionic poly(sodium 4-styrenesulfonate)-coated gold nanoparticles were found to significantly reduce THP-1 chemotaxis. Enzyme-linked immunosorbent assay results show adsorption of MCP-1 on the poly(sodium 4-styrenesulfonate)-coated gold nanoparticle surface, supporting the hypothesis that adsorption of chemoattractants to nanoparticle surfaces interferes with chemotaxis. Free anionic sulfonated polyelectrolytes also interfered with cell migrational behavior, showing that nanoparticles can also act as carriers of chemotactic-interfering molecules.
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Affiliation(s)
- Xi Zhang
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Priscila Falagan-Lotsch
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, United States
| | - Catherine J Murphy
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
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Ye B, Xiong X, Deng X, Gu L, Wang Q, Zeng Z, Gao X, Gao Q, Wang Y. Meisoindigo, but not its core chemical structure indirubin, inhibits zebrafish interstitial leukocyte chemotactic migration. PHARMACEUTICAL BIOLOGY 2017; 55:673-679. [PMID: 27981893 PMCID: PMC6130669 DOI: 10.1080/13880209.2016.1238949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 09/16/2016] [Indexed: 06/01/2023]
Abstract
CONTEXT Inflammatory disease is a big threat to human health. Leukocyte chemotactic migration is required for efficient inflammatory response. Inhibition of leukocyte chemotactic migration to the inflammatory site has been shown to provide therapeutic targets for treating inflammatory diseases. OBJECTIVE Our study was designed to discover effective and safe compounds that can inhibit leukocyte chemotactic migration, thus providing possible novel therapeutic strategy for treating inflammatory diseases. MATERIALS AND METHODS In this study, we used transgenic zebrafish model (Tg:zlyz-EGFP line) to visualize the process of leukocyte chemotactic migration. Then, we used this model to screen the hit compound and evaluate its biological activity on leukocyte chemotactic migration. Furthermore, western blot analysis was performed to evaluate the effect of the hit compound on the AKT or ERK-mediated pathway, which plays an important role in leukocyte chemotactic migration. RESULTS In this study, using zebrafish-based chemical screening, we identified that the hit compound meisoindigo (25 μM, 50 μM, 75 μM) can significantly inhibit zebrafish leukocyte chemotactic migration in a dose-dependent manner (p = 0.01, p = 0.0006, p < 0.0001). Also, we found that meisoindigo did not affect the process of leukocyte reverse migration (p = 0.43). Furthermore, our results unexpectedly showed that indirubin, the core structure of meisoindigo, had no significant effect on zebrafish leukocyte chemotactic migration (p = 0.6001). Additionally, our results revealed that meisoindigo exerts no effect on the Akt or Erk-mediated signalling pathway. DISCUSSION AND CONCLUSION Our results suggest that meisoindigo, but not indirubin, is effective for inhibiting leukocyte chemotactic migration, thus providing a potential therapeutic agent for treating inflammatory diseases.
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Affiliation(s)
- Baixin Ye
- Department of Hematology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
- State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoxing Xiong
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Xu Deng
- College of Chemistry and Molecular Science, Wuhan University, Wuhan, Hubei, China
| | - Lijuan Gu
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Qiongyu Wang
- Department of Hematology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Zhi Zeng
- Department of Pathology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Xiang Gao
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Qingping Gao
- Department of Hematology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yueying Wang
- State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Preira P, Forel JM, Robert P, Nègre P, Biarnes-Pelicot M, Xeridat F, Bongrand P, Papazian L, Theodoly O. The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-cell study: the role of cytokines and protection with antibodies. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2016; 20:8. [PMID: 26757701 PMCID: PMC4711060 DOI: 10.1186/s13054-015-1157-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 12/06/2015] [Indexed: 12/19/2022]
Abstract
Background Leukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. Methods This study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 cell line, were used. Cellular adhesiveness to human umbilical vein endothelial cells was examined using the laminar flow chamber method. We compared the properties of cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. Results Rapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 cell line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. Conclusions The leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies. Electronic supplementary material The online version of this article (doi:10.1186/s13054-015-1157-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pascal Preira
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France. .,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France.
| | - Jean-Marie Forel
- Assistance Publique - Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, 13015, Marseille, France. .,Aix-Marseille Université, Faculté de médecine, URMITE UMR CNRS 7278, 13005, Marseille, France.
| | - Philippe Robert
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France. .,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France.
| | - Paulin Nègre
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France.,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France
| | - Martine Biarnes-Pelicot
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France.,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France
| | - Francois Xeridat
- Assistance Publique - Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, 13015, Marseille, France. .,Aix-Marseille Université, Faculté de médecine, URMITE UMR CNRS 7278, 13005, Marseille, France.
| | - Pierre Bongrand
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France. .,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France.
| | - Laurent Papazian
- Assistance Publique - Hôpitaux de Marseille, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, 13015, Marseille, France. .,Aix-Marseille Université, Faculté de médecine, URMITE UMR CNRS 7278, 13005, Marseille, France.
| | - Olivier Theodoly
- Adhésion et Inflammation, Université Aix-Marseille, INSERM U1067, CNRS UMR7333, 163 avenue de Luminy, Marseille, 13009, France. .,Laboratoire d'Immunologie, Assistance Publique - Hôpitaux de Marseille, 147, boulevard Baille, F-13285 Cedx 05, Marseille, France.
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Abstract
Migration and positioning of cells is fundamental for complex functioning of multicellular organisms. During an immune response, cells are recruited from remote distances to a distinct location. Cells that are passively transported leave the circulation stimulated by locally produced signals and follow chemotactic cues to reach specific destinations. Such gradients are short (<150 μm) and require a source of production where the concentration is the highest and a sink in apposition where the attractant dissipates and the concentration is the lowest. Several straight forward methods exist to identify in vitro and in vivo cells producing chemoattractants. This can be achieved at the transcriptional level and by measuring secreted proteins. However, to demonstrate the activity of sinks in vitro and in vivo is more challenging. Cell-mediated dissipation of an attractant must be revealed by measuring its uptake and subsequent destruction. Elimination of chemoattractants such as chemokines can be monitored in vitro using radiolabeled ligands or more elegantly with fluorescent-labeled chemoattractants. The latter method can also be used in vivo and enables to monitor the process in real time using time-lapse video microscopy. In this chapter, we describe methods to produce fluorescently labeled chemokines either as fusion proteins secreted from insect cells or as recombinant bacterial proteins that can enzymatically be labeled. We discuss methods that were successfully used to demonstrate sink activities of scavenger receptors. Moreover, fluorescent chemokines can be used to noninvasively analyze receptor expression and activity in living cells.
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Affiliation(s)
- Barbara Moepps
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Marcus Thelen
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland.
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Ryan CM, Brown JAL, Bourke E, Prendergast ÁM, Kavanagh C, Liu Z, Owens P, Shaw G, Kolch W, O'Brien T, Barry FP. ROCK activity and the Gβγ complex mediate chemotactic migration of mouse bone marrow-derived stromal cells. Stem Cell Res Ther 2015. [PMID: 26204937 PMCID: PMC4603944 DOI: 10.1186/s13287-015-0125-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION Bone marrow-derived stromal cells (BMSCs), also known as mesenchymal stem cells, are the focus of intensive efforts worldwide to elucidate their function and biology. Despite the importance of BMSC migration for their potential therapeutic uses, the mechanisms and signalling governing stem cell migration are still not fully elucidated. METHODS We investigated and detailed the effects of MCP-1 activation on BMSCs by using inhibitors of G protein-coupled receptor alpha beta (GPCR αβ), ROCK (Rho-associated, coiled-coil containing protein kinase), and PI3 kinase (PI3K). The effects of MCP-1 stimulation on intracellular signalling cascades were characterised by using immunoblotting and immunofluorescence. The effectors of MCP-1-mediated migration were investigated by using migration assays (both two-dimensional and three-dimensional) in combination with inhibitors. RESULTS We established the kinetics of the MCP-1-activated signalling cascade and show that this cascade correlates with cell surface re-localisation of chemokine (C motif) receptor 2 (CCR2) (the MCP-1 receptor) to the cell periphery following MCP-1 stimulation. We show that MCP-1-initiated signalling is dependent on the activation of βγ subunits from the GPCR αβγ complex. In addition, we characterise a novel role for PI3Kγ signalling for the activation of both PAK and ERK following MCP-1 stimulation. We present evidence that the Gβγ complex is responsible for PI3K/Akt, PAK, and ERK signalling induced by MCP-1 in BMSCs. Importantly, we found that, in BMSCs, inhibition of ROCK significantly inhibits MCP-1-induced chemotactic migration, in contrast to previous reports in other systems. CONCLUSIONS Our results indicate differential chemotactic signalling in mouse BMSCs, which has important implications for the translation of in vivo mouse model findings into human trials. We identified novel components and interactions activated by MCP-1-mediated signalling, which are important for stem cell migration. This work has identified additional potential therapeutic targets that could be manipulated to improve BMSC delivery and homing.
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Affiliation(s)
- Caroline M Ryan
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland. .,Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
| | - James A L Brown
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland. .,Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland. .,Present address: Discipline of Surgery, School of Medicine, Lambe Institute, Translational Research Facility, National University of Ireland Galway, University Road, Galway, Ireland.
| | - Emer Bourke
- Discipline of Pathology, School of Medicine, National University of Ireland Galway, University Road, Galway, Ireland.
| | - Áine M Prendergast
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland. .,Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland. .,Present address: Hematopoietic Stem Cells and Stress' group, Division of Stem Cells and Cancer, Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer feld 280, 69120, Heidelberg, Germany.
| | - Claire Kavanagh
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland.
| | - Zhonglin Liu
- Department of Radiology, University of Arizona, Tucson, AZ, 85724-5067, USA.
| | - Peter Owens
- Centre for Micro and Imaging, National University of Ireland Galway, University Road, Galway, Ireland.
| | - Georgina Shaw
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland.
| | - Walter Kolch
- Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Timothy O'Brien
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland. .,Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Frank P Barry
- Regenerative Medicine Institute (REMEDI), Biosciences, National University of Ireland Galway, University Road, Galway, Ireland. .,Systems Biology Ireland, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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Herpes simplex virus enhances chemokine function through modulation of receptor trafficking and oligomerization. Nat Commun 2015; 6:6163. [PMID: 25625471 DOI: 10.1038/ncomms7163] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 12/19/2014] [Indexed: 01/13/2023] Open
Abstract
Glycoprotein G (gG) from herpes simplex virus 1 and 2 (HSV-1 and HSV-2, important human neurotropic pathogens) is the first viral chemokine-binding protein found to potentiate chemokine function. Here we show that gG attaches to cell surface glycosaminoglycans and induces lipid raft clustering, increasing the incorporation of CXCR4 receptors into these microdomains. gG induces conformational rearrangements in CXCR4 homodimers and changes their intracellular partners, leading to sustained, functional chemokine/receptor complexes at the surface. This results in increased chemotaxis dependent on the cholesterol content of the plasma membrane and receptor association to Src-kinases and phosphatidylinositol-3-kinase signalling pathways, but independent of clathrin-mediated endocytosis. Furthermore, using electron microscopy, we show that such enhanced functionality is associated with the accumulation of low-order CXCR4 nanoclusters. Our results provide insights into basic mechanisms of chemokine receptor function and into a viral strategy of immune modulation.
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Wu YS, Nan FH, Huang SL, Hsiao CM, Lai KC, Lu CL, Chen SN. Studies of macrophage cellular response to the extracellular hydrogen peroxide by tilapia model. FISH & SHELLFISH IMMUNOLOGY 2014; 36:459-466. [PMID: 24398263 DOI: 10.1016/j.fsi.2013.12.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 06/03/2023]
Abstract
Reactive oxygen species (ROS) may act as signaling molecules in the physiology responses and the present study aims to investigate the effect of extracellular hydrogen peroxide on macrophages cellular response. The results obtained in the present study showed that the extracellular hydrogen peroxide affectively alter the membrane potential of the cell membrane and ion exchange channels in the cell membrane through intracellular NAD turnover that may lead to an intracellular calcium ion concentration alteration and subsequently induce the downstream signal activation.
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Affiliation(s)
- Yu-Sheng Wu
- Institute of Fisheries Science, National Taiwan University, Taipei 10617, Taiwan
| | - Fan-Hua Nan
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20248, Taiwan
| | - Shih-Ling Huang
- Freshwater Aquaculture Research Center, Fisheries Research Institute, Council of Agriculture, Changhua 50562, Taiwan
| | - Chien-Mei Hsiao
- Institute of Fisheries Science, National Taiwan University, Taipei 10617, Taiwan
| | - Kam-Chiu Lai
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chung-Lun Lu
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Shiu-Nan Chen
- Institute of Fisheries Science, National Taiwan University, Taipei 10617, Taiwan; Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.
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Volpe S, Cameroni E, Moepps B, Thelen S, Apuzzo T, Thelen M. CCR2 acts as scavenger for CCL2 during monocyte chemotaxis. PLoS One 2012; 7:e37208. [PMID: 22615942 PMCID: PMC3355119 DOI: 10.1371/journal.pone.0037208] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 04/18/2012] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Leukocyte migration is essential for effective host defense against invading pathogens and during immune homeostasis. A hallmark of the regulation of this process is the presentation of chemokines in gradients stimulating leukocyte chemotaxis via cognate chemokine receptors. For efficient migration, receptor responsiveness must be maintained whilst the cells crawl on cell surfaces or on matrices along the attracting gradient towards increasing concentrations of agonist. On the other hand agonist-induced desensitization and internalization is a general paradigm for chemokine receptors which is inconsistent with the prolonged migratory capacity. METHODOLOGY/PRINCIPAL FINDINGS Chemotaxis of monocytes was monitored in response to fluorescent CCL2-mCherry by time-lapse video microscopy. Uptake of the fluorescent agonist was used as indirect measure to follow the endogenous receptor CCR2 expressed on primary human monocytes. During chemotaxis CCL2-mCherry becomes endocytosed as cargo of CCR2, however, the internalization of CCR2 is not accompanied by reduced responsiveness of the cells due to desensitization. CONCLUSIONS/SIGNIFICANCE During chemotaxis CCR2 expressed on monocytes internalizes with the bound chemoattractant, but cycles rapidly back to the plasma membrane to maintain high responsiveness. Moreover, following relocation of the source of attractant, monocytes can rapidly reverse their polarization axis organizing a new leading edge along the newly formed gradient, suggesting a uniform distribution of highly receptive CCR2 on the plasma membrane. The present observations further indicate that during chemotaxis CCR2 acts as scavenger consuming the chemokine forming the attracting cue.
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Affiliation(s)
- Silvia Volpe
- Institute for Research in Biomedicine, Bellinzona, Switzerland
| | | | - Barbara Moepps
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Sylvia Thelen
- Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - Tiziana Apuzzo
- Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - Marcus Thelen
- Institute for Research in Biomedicine, Bellinzona, Switzerland
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