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Zhang W, Chen L, Lu X, Dong X, Feng M, Tu Y, Wang Z. EFHD2 regulates T cell receptor signaling and modulates T helper cell activation in early sepsis. Int Immunopharmacol 2024; 133:112087. [PMID: 38669951 DOI: 10.1016/j.intimp.2024.112087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024]
Abstract
EFHD2 (EF-hand domain family, member D2) has been identified as a calcium-binding protein with immunomodulatory effects. In this study, we characterized the phenotype of Efhd2-deficient mice in sepsis and examined the biological functions of EFHD2 in peripheral T cell activation and T helper (Th) cell differentiation. Increased levels of EFHD2 expression accompanied peripheral CD4+ T cell activation in the early stages of sepsis. Transcriptomic analysis indicated that immune response activation was impaired in Efhd2-deficient CD4+ T cells. Further, Efhd2-deficient CD4+ T cells isolated from the spleen of septic mice showed impaired T cell receptor (TCR)-induced Th differentiation, especially Th1 and Th17 differentiation. In vitro data also showed that Efhd2-deficient CD4+ T cells exhibit impaired Th1 and Th17 differentiation. In the CD4+ T cells and macrophages co-culture model for antigen presentation, the deficiency of Efhd2 in CD4+ T cells resulted in impaired formation of immunological synapses. In addition, Efhd2-deficient CD4+ T cells exhibited reduced levels of phospho-LCK and phospho-ZAP70, and downstream transcription factors including Nfat, Nfκb and Nur77 following TCR engagement. In summary, EFHD2 may promote TCR-mediated T cell activation subsequent Th1 and Th17 differentiation in the early stages of sepsis by regulating the intensity of TCR complex formation.
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Affiliation(s)
- Wenzhao Zhang
- Department of Critical Care Medicine, School of Anesthesiology, Naval Medical University, Shanghai 200433, China
| | - Linlin Chen
- Department of Critical Care Medicine, School of Anesthesiology, Naval Medical University, Shanghai 200433, China
| | - Xin Lu
- Department of Critical Care Medicine, School of Anesthesiology, Naval Medical University, Shanghai 200433, China
| | - Xiaohui Dong
- Department of Pharmacy, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Meixia Feng
- Department of Critical Care Medicine, School of Anesthesiology, Naval Medical University, Shanghai 200433, China
| | - Ye Tu
- Department of Pharmacy, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200092, China.
| | - Zhibin Wang
- Department of Critical Care Medicine, School of Anesthesiology, Naval Medical University, Shanghai 200433, China.
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Pauker MH, Reicher B, Joseph N, Wortzel I, Jakubowicz S, Noy E, Perl O, Barda-Saad M. WASp family verprolin-homologous protein-2 (WAVE2) and Wiskott-Aldrich syndrome protein (WASp) engage in distinct downstream signaling interactions at the T cell antigen receptor site. J Biol Chem 2014; 289:34503-19. [PMID: 25342748 DOI: 10.1074/jbc.m114.591685] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
T cell antigen receptor (TCR) engagement has been shown to activate pathways leading to actin cytoskeletal polymerization and reorganization, which are essential for lymphocyte activation and function. Several actin regulatory proteins were implicated in regulating the actin machinery, such as members of the Wiskott-Aldrich syndrome protein (WASp) family. These include WASp and the WASp family verprolin-homologous protein-2 (WAVE2). Although WASp and WAVE2 share several structural features, the precise regulatory mechanisms and potential redundancy between them have not been fully characterized. Specifically, unlike WASp, the dynamic molecular interactions that regulate WAVE2 recruitment to the cell membrane and specifically to the TCR signaling complex are largely unknown. Here, we identify the molecular mechanism that controls the recruitment of WAVE2 in comparison with WASp. Using fluorescence resonance energy transfer (FRET) and novel triple-color FRET (3FRET) technology, we demonstrate how WAVE2 signaling complexes are dynamically regulated during lymphocyte activation in vivo. We show that, similar to WASp, WAVE2 recruitment to the TCR site depends on protein-tyrosine kinase, ZAP-70, and the adaptors LAT, SLP-76, and Nck. However, in contrast to WASp, WAVE2 leaves this signaling complex and migrates peripherally together with vinculin to the membrane leading edge. Our experiments demonstrate that WASp and WAVE2 differ in their dynamics and their associated proteins. Thus, this study reveals the differential mechanisms regulating the function of these cytoskeletal proteins.
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Affiliation(s)
- Maor H Pauker
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Barak Reicher
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Noah Joseph
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Inbal Wortzel
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Shlomi Jakubowicz
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Elad Noy
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Orly Perl
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Mira Barda-Saad
- From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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3
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Yang Z, Sun J, Yang X, Zhang Z, Lou B, Xiong J, Schluesener HJ, Zhang Z. Accumulation of fascin+ cells during experimental autoimmune neuritis. Diagn Pathol 2013; 8:213. [PMID: 24369046 PMCID: PMC3877979 DOI: 10.1186/1746-1596-8-213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 11/27/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Experimental autoimmune neuritis (EAN) is a well-known animal model of human demyelinating polyneuropathies and is characterized by inflammation and demyelination in the peripheral nervous system. Fascin is an evolutionarily highly conserved cytoskeletal protein of 55 kDa containing two actin binding domains that cross-link filamentous actin to hexagonal bundles. METHODS Here we have studied by immunohistochemistry the spatiotemporal accumulation of Fascin + cells in sciatic nerves of EAN rats. RESULTS A robust accumulation of Fascin + cell was observed in the peripheral nervous system of EAN which was correlated with the severity of neurological signs in EAN. CONCLUSION Our results suggest a pathological role of Fascin in EAN. VIRTUAL SLIDES The virtual slides for this article can be found here: http://www.diagnosticphatology.diagnomx.eu/vs/6734593451114811.
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Affiliation(s)
| | | | | | | | | | | | | | - Zhiren Zhang
- Institute of Immunology, Third Military Medical University of PLA, 30 Gaotanyan Main Street, Chongqing 400038, People's Republic of China.
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Samstag Y, John I, Wabnitz GH. Cofilin: a redox sensitive mediator of actin dynamics during T-cell activation and migration. Immunol Rev 2013; 256:30-47. [PMID: 24117811 PMCID: PMC3884758 DOI: 10.1111/imr.12115] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cofilin is an actin-binding protein that depolymerizes and/or severs actin filaments. This dual function of cofilin makes it one of the major regulators of actin dynamics important for T-cell activation and migration. The activity of cofilin is spatio-temporally regulated. Its main control mechanisms comprise a molecular toolbox of phospho-, phospholipid, and redox regulation. Phosphorylated cofilin is inactive and represents the dominant cofilin fraction in the cytoplasm of resting human T cells. A fraction of dephosphorylated cofilin is kept inactive at the plasma membrane by binding to phosphatidylinositol 4,5-bisphosphate. Costimulation via the T-cell receptor/CD3 complex (signal 1) together with accessory receptors (signal 2) or triggering through the chemokine SDF1α (stromal cell-derived factor 1α) induce Ras-dependent dephosphorylation of cofilin, which is important for immune synapse formation, T-cell activation, and T-cell migration. Recently, it became evident that cofilin is also highly sensitive for microenvironmental changes, particularly for alterations in the redox milieu. Cofilin is inactivated by oxidation, provoking T-cell hyporesponsiveness or necrotic-like programmed cell death. In contrast, in a reducing environment, even phosphatidylinositol 4,5-bisphosphate-bound cofilin becomes active, leading to actin dynamics in the vicinity of the plasma membrane. In addition to the well-established three signals for T-cell activation, this microenvironmental control of cofilin delivers a modulating signal for T-cell-dependent immune reactions. This fourth modulating signal highly impacts both initial T-cell activation and the effector phase of T-cell-mediated immune responses.
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Affiliation(s)
- Yvonne Samstag
- Institute for Immunology, Ruprecht-Karls-UniversityHeidelberg, Germany
| | - Isabel John
- Institute for Immunology, Ruprecht-Karls-UniversityHeidelberg, Germany
| | - Guido H Wabnitz
- Institute for Immunology, Ruprecht-Karls-UniversityHeidelberg, Germany
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5
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Functional cooperation between the proteins Nck and ADAP is fundamental for actin reorganization. Mol Cell Biol 2011; 31:2653-66. [PMID: 21536650 DOI: 10.1128/mcb.01358-10] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
T cell antigen receptor (TCR) activation triggers profound changes in the actin cytoskeleton. In addition to controlling cellular shape and polarity, this process regulates vital T cell responses, such as T cell adhesion, motility, and proliferation. These depend on the recruitment of the signaling proteins Nck and Wiskott-Aldrich syndrome protein (WASp) to the site of TCR activation and on the functional properties of the adapter proteins linker for activation of T cells (LAT) and SH2-domain-containing leukocyte protein of 76 kDa (SLP76). We now demonstrate that Nck is necessary but insufficient for the recruitment of WASp. We show that two pathways lead to SLP76-dependent actin rearrangement. One requires the SLP76 acidic domain, crucial to association with the Nck SH2 domain, and another requires the SLP76 SH2 domain, essential for interaction with the adhesion- and degranulation-promoting adapter protein ADAP. Functional cooperation between Nck and ADAP mediates SLP76-WASp interactions and actin rearrangement. We also reveal the molecular mechanism linking ADAP to actin reorganization.
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Miguel L, Owen DM, Lim C, Liebig C, Evans J, Magee AI, Jury EC. Primary human CD4+ T cells have diverse levels of membrane lipid order that correlate with their function. THE JOURNAL OF IMMUNOLOGY 2011; 186:3505-16. [PMID: 21307290 DOI: 10.4049/jimmunol.1002980] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Membrane lipid microdomains (lipid rafts) play an important role in T cell function by forming areas of high lipid order that facilitate activation. However, their role in regulating T cell differentiation and function remains controversial. In this study, by applying a new approach involving microscopy and flow cytometry, we characterize membrane lipid order in ex vivo primary human CD4(+) T cells. We reveal that differential membrane lipid order dictates the response to TCR stimulation. T cells with high membrane order formed stable immune synapses and proliferated robustly, intermediate order cells had reduced proliferative ability accompanied by unstable immune synapse formation, whereas low order T cells were profoundly unresponsive to TCR activation. We also observed that T cells from patients with autoimmune rheumatic disease had expanded intermediate order populations compared with healthy volunteers. This may be important in dictating the nature of the immune response since most IFN-γ(+)CD4(+) T cells were confined within intermediate membrane order populations, whereas IL-4(+)CD4(+) T cells were contained within the high order populations. Importantly, we were able to alter T cell function by pharmacologically manipulating membrane order. Thus, the results presented from this study identify that ex vivo CD4(+) T cells sustain a gradient of plasma membrane lipid order that influences their function in terms of proliferation and cytokine production. This could represent a new mechanism to control T cell functional plasticity, raising the possibility that therapeutic targeting of membrane lipid order could direct altered immune cell activation in pathology.
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Affiliation(s)
- Laura Miguel
- Division of Medicine, Centre for Rheumatology Research, University College London, London W1P 4JF, United Kingdom
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7
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Borro M, Gentile G, De Luca O, Torre MS, Aimati L, Tatarelli C, Antonietta Aloe Spiriti M, Christina Cox M, Simmaco M. Specific effects exerted by B-lymphoproliferative diseases on peripheral T-lymphocyte protein expression. Br J Haematol 2010; 150:463-72. [PMID: 20618332 DOI: 10.1111/j.1365-2141.2010.08285.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A proteomic approach was applied to study the protein expression profile of peripheral T-cells derived from patients at the onset of different B-lymphoproliferative diseases, because a rising interest in specific actions played by T-cells in such pathologies has emerged. Decreased levels of profilin-1 and cofilin-1 and increased levels of coronin1A and prohibitin were found in patients, compared with healthy controls. The protein-protein interaction network of these proteins was studied using a web-based bioinformatics tool, highlighting the actin cytoskeleton regulation as the main biological process involved in peripheral T-cells of such patients. Unsupervised cluster analysis of protein expression data shows that the recorded alteration of T-cell proteome was specifically induced by B-cell pathologies.
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Affiliation(s)
- Marina Borro
- 2nd Faculty of Medicine, Sant'Andrea Hospital, Sapienza University of Rome, Italy
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8
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Schartner JM, Simonson WT, Wernimont SA, Nettenstrom LM, Huttenlocher A, Seroogy CM. Gene related to anergy in lymphocytes (GRAIL) expression in CD4+ T cells impairs actin cytoskeletal organization during T cell/antigen-presenting cell interactions. J Biol Chem 2009; 284:34674-81. [PMID: 19833735 PMCID: PMC2787330 DOI: 10.1074/jbc.m109.024497] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Revised: 09/30/2009] [Indexed: 11/06/2022] Open
Abstract
GRAIL (gene related to anergy in lymphocytes), is an E3 ubiquitin ligase with increased expression in anergic CD4+ T cells. The expression of GRAIL has been shown to be both necessary and sufficient for the induction of T cell (T) anergy. To date, several subsets of anergic T cells have demonstrated altered interactions with antigen-presenting cells (APC) and perturbed TCR-mediated signaling. The role of GRAIL in mediating these aspects of T cell anergy remains unclear. We used flow cytometry and confocal microscopy to examine T/APC interactions in GRAIL-expressing T cells. Increased GRAIL expression resulted in reduced T/APC conjugation efficiency as assessed by flow cytometry. Examination of single T/APC conjugates by confocal microscopy revealed altered polarization of polymerized actin and LFA-1 to the T/APC interface. When GRAIL expression was knocked down, actin polarization to the T/APC interface was restored, demonstrating that GRAIL is necessary for alteration of actin cytoskeletal rearrangement under anergizing conditions. Interestingly, proximal TCR signaling including calcium flux and phosphorylation of Vav were not disrupted by expression of GRAIL in CD4+ T cells. In contrast, interrogation of distal signaling events demonstrated significantly decreased JNK phosphorylation in GRAIL-expressing T cells. In sum, GRAIL expression in CD4+ T cells mediates alterations in the actin cytoskeleton during T/APC interactions. Moreover, in this model, our data dissociates proximal T cell signaling events from functional unresponsiveness. These data demonstrate a novel role for GRAIL in modulating T/APC interactions and provide further insight into the cell biology of anergic T cells.
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Affiliation(s)
- Jill M. Schartner
- From the Departments of Cellular and Molecular Pathology
- Pediatrics, Division of Allergy/Immunology/Rheumatology, University of Wisconsin, Madison, Wisconsin 53792
| | | | | | - Lauren M. Nettenstrom
- Pediatrics, Division of Allergy/Immunology/Rheumatology, University of Wisconsin, Madison, Wisconsin 53792
| | - Anna Huttenlocher
- Pediatrics, Division of Allergy/Immunology/Rheumatology, University of Wisconsin, Madison, Wisconsin 53792
| | - Christine M. Seroogy
- Pediatrics, Division of Allergy/Immunology/Rheumatology, University of Wisconsin, Madison, Wisconsin 53792
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9
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Morton AM, McManus B, Garside P, Mowat AM, Harnett MM. Inverse Rap1 and Phospho-ERK Expression Discriminate the Maintenance Phase of Tolerance and Priming of Antigen-Specific CD4+ T Cells In Vitro and In Vivo. THE JOURNAL OF IMMUNOLOGY 2007; 179:8026-34. [DOI: 10.4049/jimmunol.179.12.8026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Visualizing the Immune Synapse. Biol Blood Marrow Transplant 2007. [DOI: 10.1016/j.bbmt.2006.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Su L, Lineberry N, Huh Y, Soares L, Fathman CG. A Novel E3 Ubiquitin Ligase Substrate Screen Identifies Rho Guanine Dissociation Inhibitor as a Substrate of Gene Related to Anergy in Lymphocytes. THE JOURNAL OF IMMUNOLOGY 2006; 177:7559-66. [PMID: 17114425 DOI: 10.4049/jimmunol.177.11.7559] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ubiquitination of eukaryotic proteins regulates a broad range of cellular processes, including regulation of T cell activation and tolerance. We have previously demonstrated that gene related to anergy in lymphocytes (GRAIL), a ring finger ubiquitin E3 ligase, is required for the induction of T cell anergy; however, the substrate(s) for GRAIL E3 ligase activity is/are unknown. In this study, we report a novel prokaryotic system developed to screen for substrates of E3 ligases. Using this screen, Rho guanine dissociation inhibitor (RhoGDI) was identified as a potential substrate of GRAIL. GRAIL was subsequently demonstrated to bind and ubiquitinate RhoGDI, although GRAIL-mediated ubiquitination of RhoGDI did not result in proteosomal degradation. Expression of GRAIL in T cells resulted in specific inhibition of RhoA GTPase activation; activation of Rac1, cdc42, and Ras GTPases were not affected. Interestingly, stable T cell lines expressing dominant-negative RhoA mimicked the GRAIL-mediated IL-2 inhibition phenotype, and T cells expressing constitutively active RhoA were able to overcome GRAIL-mediated inhibition of IL-2 expression. These findings validate our prokaryotic screen as a method of identifying substrates for ubiquitin E3 ligases and suggest a role for Rho effector molecules in T cell anergy.
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Affiliation(s)
- Leon Su
- Department of Medicine, Division of Immunology and Rheumatology, Stanford University, Stanford, CA 94305, USA
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12
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Ocklenburg F, Moharregh-Khiabani D, Geffers R, Janke V, Pfoertner S, Garritsen H, Groebe L, Klempnauer J, Dittmar KEJ, Weiss S, Buer J, Probst-Kepper M. UBD, a downstream element of FOXP3, allows the identification of LGALS3, a new marker of human regulatory T cells. J Transl Med 2006; 86:724-37. [PMID: 16702978 DOI: 10.1038/labinvest.3700432] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Here, we report the identification of the ubiquitin-like gene UBD as a downstream element of FOXP3 in human activated regulatory CD4(+)CD25(hi) T cells (T(reg)). Retroviral transduction of UBD in human allo-reactive effector CD4(+) T helper (T(h)) cells upregulates CD25 and mediates downregulation of IL4 and IL5 expression similar to overexpression of FOXP3. Moreover, UBD impairs T(h) cell proliferation without upregulation of FOXP3 and impairs calcium mobilization. In the presence of ionomycin, overexpression of UBD in T(h) cells leads to the induction of IL1R2 that resemble FOXP3-transduced T(h) cells and naturally derived T(reg) cells. A comparison of the transcriptome of FOXP3- and UBD-transduced T(h) cells with T(reg) cells allowed the identification of the gene LGALS3. However, high levels of LGALS3 protein expression were observed only in human CD4(+)CD25(hi) derived T(reg) cells and FOXP3-transduced T(h) cells, whereas little was induced in UBD-transduced T(h) cells. Thus, UBD contributes to the anergic phenotype of human regulatory T cells and acts downstream in FOXP3 induced regulatory signaling pathways, including regulation of LGALS3 expression. High levels of LGALS3 expression represent a FOXP3-signature of human antigen-stimulated CD4(+)CD25(hi) derived regulatory T cells.
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Affiliation(s)
- Frank Ocklenburg
- Junior Research Group for Xenotransplantation, Department of Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany
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13
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Stradal TEB, Pusch R, Kliche S. Molecular regulation of cytoskeletal rearrangements during T cell signalling. Results Probl Cell Differ 2006; 43:219-44. [PMID: 17068974 DOI: 10.1007/400_022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Regulation of the cytoskeleton in cells of the haematopoietic system is essential for fulfilling diverse tasks such as migration towards a chemoattractant, phagocytosis or cell-cell communication. This is particularly true for the many types of T cells, which are at the foundation of the adaptive immune system in vertebrates. Deregulation of actin filament turnover is known to be involved in the development of severe immunodeficiencies or immunoproliferative diseases. Therefore, molecular dissection of signalling complexes and effector molecules, which leads to controlled cytoskeletal assembly, has been the focus of immunological research in the last decade. In the past, cytoskeletal remodelling was frequently understood as the finish line of signalling, while today it becomes increasingly evident that actin and microtubule dynamics are required for proper signal transmission in many processes such as T cell activation. Significant effort is made in many laboratories to further elucidate the contribution of cytoskeletal remodelling to immune function. The objective of this article is to summarise the current knowledge on how actin and microtubules are reorganised to support the formation of structures as diverse as the immunological synapse and peripheral protrusions during cell migration.
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Affiliation(s)
- Theresia E B Stradal
- Signalling and Motility Group, German Research Centre for Biotechnology (GBF), Braunschweig, Germany
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14
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Sugihara A, Okamoto H, Horio T. Effects of UVB on fascin expression in dendritic cells and Langerhans cells. J Dermatol Sci 2005; 40:177-85. [PMID: 15993570 DOI: 10.1016/j.jdermsci.2005.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2004] [Revised: 04/28/2005] [Accepted: 05/06/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Fascin is an actin-binding protein that regulates the rearrangement of cytoskeletal elements and their interactions with the cell membrane. Previous studies have indicated that fascin expression is enhanced in DC upon maturation and plays a critical role in T cell activation. Ultraviolet irradiation exerts immunosuppressive effects. OBJECTIVE We examined the effects of UVB irradiation on the interaction of DC/LC with T cells through fascin. METHOD Murine bone marrow-derived DC (BM-DC) were induced by recombinant murine GM-CSF and LPS, and UVB irradiation was applied prior to supplementation with LPS. I-A(+) cells (Langerhans cells (LC)) in the epidermal cell suspensions were exposed to UVB irradiation at the beginning of the 24-h culture. BM-DC and LC were analysed by immunohistochemical staining and flow cytometric analyses. To evaluate the effects of UVB irradiation on DC-T cell binding, we examined the clustering of BM-DC with allogeneic CD4(+) T cells under a confocal microscope. RESULTS Fascin expression in BM-DC and LC was decreased by UVB irradiation. Furthermore, UVB irradiation reduced the ability of BM-DC to cluster with allogeneic CD4(+) T cells. Polarization of fascin and filamentous actin (F-actin) at the point of contact of BM-DC with T cells was also disturbed by UVB irradiation. CONCLUSION These results suggest that the suppression of fascin expression by UVB irradiation down-regulates the rearrangement of the cytoskeleton and, thereby, antigen presentation in DC/LC.
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Affiliation(s)
- Akira Sugihara
- Department of Dermatology, Kansai Medical University, Fumizono 10-15, Moriguchi, Osaka 570-8507, Japan.
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15
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Adams CL, Grierson AM, Mowat AM, Harnett MM, Garside P. Differences in the Kinetics, Amplitude, and Localization of ERK Activation in Anergy and Priming Revealed at the Level of Individual Primary T Cells by Laser Scanning Cytometry. THE JOURNAL OF IMMUNOLOGY 2004; 173:1579-86. [PMID: 15265885 DOI: 10.4049/jimmunol.173.3.1579] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
One of the potential mechanisms of peripheral tolerance is the unresponsiveness of T cells to secondary antigenic stimulation as a result of the induction of anergy. It has been widely reported that antigenic unresponsiveness may be due to uncoupling of MAPK signal transduction pathways. However, such signaling defects in anergic T cell populations have been mainly identified using immortalized T cell lines or T cell clones, which do not truly represent primary Ag-specific T cells. We have therefore attempted to quantify signaling events in murine primary Ag-specific T cells on an individual cell basis, using laser-scanning cytometry. We show that there are marked differences in the amplitude and cellular localization of phosphorylated ERK p42/p44 (ERK1/2) signals when naive, primed and anergic T cells are challenged with peptide-pulsed dendritic cells. Primed T cells display more rapid kinetics of phosphorylation and activation of ERK than naive T cells, whereas anergic T cells display a reduced ability to activate ERK1/2 upon challenge. In addition, the low levels of pERK found in anergic T cells are distributed diffusely throughout the cell, whereas in primed T cells, pERK appears to be targeted to the same regions of the cell as the TCR. These data suggest that the different consequences of Ag recognition by T cells are associated with distinctive kinetics, amplitude, and localization of MAPK signaling.
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Affiliation(s)
- Claire L Adams
- Division of Immunology, Infection and Inflammation, University of Glasgow, Western Infirmary, Glasgow, United Kingdom
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Affiliation(s)
- Antonio S Sechi
- Institute for Biomedical Technology-Cell Biology, Uniklinikum Aachen, RWTH, Pauwelsstrasse 30, D-52057 Aachen, Germany.
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Abstract
PURPOSE OF REVIEW This review focuses on recent developments in understanding the roles and regulation of the cytoskeleton in the function of leukocytes. RECENT FINDINGS New studies have shed light on the regulation and dynamics of actin and microtubules in leukocytes relevant both to cell motility generally and to immune function specifically. The roles of cytoskeletal dynamics in processes such as cell activation, cell migration, and phagocytosis are being elucidated. Dramatic progress has been made recently in understanding the mechanisms of leukocyte directional sensing, polarization, and chemotaxis. SUMMARY Leukocytes need to be activated, polarize, change shape, move, or phagocytose in response to their environment. Leukocytes accomplish these processes by remodeling their cytoskeleton, the active musculoskeletal system of the cell that is not just the ultimate effector of motile responses but is also a dynamic framework for subcellular organization and regional signaling. Active areas of research include the direct and indirect reciprocal interactions between the cytoskeleton and the membrane and among cytoskeletal elements. The pervasive and multi-layered roles played by small GTPases of the Rho family and phosphoinositides in leukocyte function are also becoming clearer.
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Affiliation(s)
- Gabriel Fenteany
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607-7061, USA.
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