1
|
Stergiou IE, Papadakos SP, Karyda A, Tsitsilonis OE, Dimopoulos MA, Theocharis S. EPH/Ephrin Signaling in Normal Hematopoiesis and Hematologic Malignancies: Deciphering Their Intricate Role and Unraveling Possible New Therapeutic Targets. Cancers (Basel) 2023; 15:3963. [PMID: 37568780 PMCID: PMC10417178 DOI: 10.3390/cancers15153963] [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: 06/17/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Erythropoietin-producing hepatocellular carcinoma receptors (EPHs) represent the largest family of receptor tyrosine kinases (RTKs). EPH interaction with ephrins, their membrane-bound ligands, holds a pivotal role in embryonic development, while, though less active, it is also implicated in various physiological functions during adult life. In normal hematopoiesis, different patterns of EPH/ephrin expression have been correlated with hematopoietic stem cell (HSC) maintenance and lineage-committed hematopoietic progenitor cell (HPC) differentiation, as well as with the functional properties of their mature offspring. Research in the field of hematologic malignancies has unveiled a rather complex involvement of the EPH/ephrinsignaling pathway in the pathophysiology of these neoplasms. Aberrations in genetic, epigenetic, and protein levels have been identified as possible players implicated both in tumor progression and suppression, while correlations have also been highlighted regarding prognosis and response to treatment. Initial efforts to therapeutically target the EPH/ephrin axis have been undertaken in the setting of hematologic neoplasia but are mainly confined to the preclinical level. To this end, deciphering the complexity of this signaling pathway both in normal and malignant hematopoiesis is necessary.
Collapse
Affiliation(s)
- Ioanna E. Stergiou
- Department of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Stavros P. Papadakos
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (A.K.)
| | - Anna Karyda
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (A.K.)
| | - Ourania E. Tsitsilonis
- Flow Cytometry Unit, Department of Biology, School of Science, National and Kapodistrian University of Athens, 15784 Athens, Greece;
| | - Meletios-Athanasios Dimopoulos
- Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Alexandra Hospital, 11528 Athens, Greece
| | - Stamatios Theocharis
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece; (S.P.P.); (A.K.)
| |
Collapse
|
2
|
García-Ceca J, Montero-Herradón S, González A, Plaza R, Zapata AG. Altered thymocyte development observed in EphA4-deficient mice courses with changes in both thymic epithelial and extracellular matrix organization. Cell Mol Life Sci 2022; 79:583. [PMID: 36334147 PMCID: PMC9637064 DOI: 10.1007/s00018-022-04610-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/30/2022] [Accepted: 10/20/2022] [Indexed: 11/07/2022]
Abstract
Eph receptors and their ligands, Ephrins, are involved in the thymocyte-thymic epithelial cell (TEC) interactions, key for the functional maturation of both thymocytes and thymic epithelium. Several years ago, we reported that the lack of EphA4, a Eph of the subfamily A, coursed with reduced proportions of double positive (DP) thymocytes apparently due to an altered thymic epithelial stroma [Munoz et al. in J Immunol 177:804–813, 2006]. In the present study, we reevaluate the lymphoid, epithelial, and extracellular matrix (ECM) phenotype of EphA4−/− mice grouped into three categories with respect to their proportions of DP thymocytes. Our results demonstrate a profound hypocellularity, specific alterations of T cell differentiation that affected not only DP thymocytes, but also double negative and single positive T cell subsets, as well as the proportions of positively and negatively selected thymocytes. In correlation, thymic histological organization changed markedly, especially in the cortex, as well as the proportions of both Ly51+UEA-1− cortical TECs and Ly51−UEA-1+ medullary TECs. The alterations observed in the expression of ECM components (Fibronectin, Laminin, Collagen IV), integrin receptors (VLA-4, VLA-6), chemokines (CXCL12, CCL25, CCL21) and their receptors (CXCR4, CCR7, CCR9) and in vitro transwell assays on the capacity of migration of WT and mutant thymocytes suggest that the lack of EphA4 alters T-cell differentiation by presumably affecting cell adhesion between TECs and T-TEC interactions rather than by thymocyte migration.
Collapse
Affiliation(s)
- Javier García-Ceca
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040, Madrid, Spain.,Health Research Institute, Hospital 12 de Octubre (imas12), 28041, Madrid, Spain
| | - Sara Montero-Herradón
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040, Madrid, Spain.,Health Research Institute, Hospital 12 de Octubre (imas12), 28041, Madrid, Spain
| | - Ana González
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040, Madrid, Spain
| | - Rosa Plaza
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040, Madrid, Spain
| | - Agustín G Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040, Madrid, Spain. .,Health Research Institute, Hospital 12 de Octubre (imas12), 28041, Madrid, Spain.
| |
Collapse
|
3
|
García-Ceca J, Montero-Herradón S, Zapata AG. Intrathymic Selection and Defects in the Thymic Epithelial Cell Development. Cells 2020; 9:cells9102226. [PMID: 33023072 PMCID: PMC7601110 DOI: 10.3390/cells9102226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 02/07/2023] Open
Abstract
Intimate interactions between thymic epithelial cells (TECs) and thymocytes (T) have been repeatedly reported as essential for performing intrathymic T-cell education. Nevertheless, it has been described that animals exhibiting defects in these interactions were capable of a proper positive and negative T-cell selection. In the current review, we first examined distinct types of TECs and their possible role in the immune surveillance. However, EphB-deficient thymi that exhibit profound thymic epithelial (TE) alterations do not exhibit important immunological defects. Eph and their ligands, the ephrins, are implicated in cell attachment/detachment and govern, therefore, TEC–T interactions. On this basis, we hypothesized that a few normal TE areas could be enough for a proper phenotypical and functional maturation of T lymphocytes. Then, we evaluated in vivo how many TECs would be necessary for supporting a normal T-cell differentiation, concluding that a significantly low number of TEC are still capable of supporting normal T lymphocyte maturation, whereas with fewer numbers, T-cell maturation is not possible.
Collapse
Affiliation(s)
- Javier García-Ceca
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040 Madrid, Spain; (J.G.-C.); (S.M.-H.)
- Health Research Institute, Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
| | - Sara Montero-Herradón
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040 Madrid, Spain; (J.G.-C.); (S.M.-H.)
- Health Research Institute, Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
| | - Agustín G. Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040 Madrid, Spain; (J.G.-C.); (S.M.-H.)
- Health Research Institute, Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
- Correspondence: ; Tel.: +34-91-394-4979
| |
Collapse
|
4
|
Harnessing the Power of Eph/ephrin Biosemiotics for Theranostic Applications. Pharmaceuticals (Basel) 2020; 13:ph13060112. [PMID: 32492868 PMCID: PMC7345574 DOI: 10.3390/ph13060112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 02/07/2023] Open
Abstract
Comprehensive basic biological knowledge of the Eph/ephrin system in the physiologic setting is needed to facilitate an understanding of its role and the effects of pathological processes on its activity, thereby paving the way for development of prospective therapeutic targets. To this end, this review briefly addresses what is currently known and being investigated in order to highlight the gaps and possible avenues for further investigation to capitalize on their diverse potential.
Collapse
|
5
|
Darling TK, Lamb TJ. Emerging Roles for Eph Receptors and Ephrin Ligands in Immunity. Front Immunol 2019; 10:1473. [PMID: 31333644 PMCID: PMC6620610 DOI: 10.3389/fimmu.2019.01473] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022] Open
Abstract
Eph receptors are the largest family of receptor tyrosine kinases and mediate a myriad of essential processes in humans from embryonic development to adult tissue homeostasis through interactions with membrane-bound ephrin ligands. The ubiquitous expression of Eph receptors and ephrin ligands among the cellular players of the immune system underscores the importance of these molecules in orchestrating an optimal immune response. This review provides an overview of the various roles of Eph receptors and ephrin ligands in immune cell development, activation, and migration. We also discuss the role of Eph receptors in disease pathogenesis as well as the implications of Eph receptors as future immunotherapy targets. Given the diverse and critical roles of Eph receptors and ephrin ligands throughout the immune system during both resting and activated states, this review aims to highlight the critical yet underappreciated roles of this family of signaling molecules in the immune system.
Collapse
Affiliation(s)
- Thayer K Darling
- Immunology and Molecular Pathogenesis Program, Emory University Laney Graduate School, Atlanta, GA, United States.,Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - Tracey J Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT, United States
| |
Collapse
|
6
|
Alfaro D, Zapata AG. Eph/Ephrin-mediated stimulation of human bone marrow mesenchymal stromal cells correlates with changes in cell adherence and increased cell death. Stem Cell Res Ther 2018; 9:172. [PMID: 29941036 PMCID: PMC6019728 DOI: 10.1186/s13287-018-0912-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/11/2018] [Accepted: 05/21/2018] [Indexed: 12/14/2022] Open
Abstract
Background Mesenchymal stromal cells (MSC) are components of connective tissues and, in vitro, cell entities characterized by cell adhesion and immunophenotyping, although specific markers for their identification are lacking. Currently, MSC derived from either human bone marrow (BM-MSC) or adipose tissue (Ad-MSC) are considered the main sources of MSC for cell therapy. Eph receptors and their ligands, Ephrins, are molecules involved in cell adhesion and migration in several tissues and organs. In the current study, we analyze the pattern of Eph/Ephrin expression in MSC and evaluate the effects of blockade and stimulation of these receptor/ligand pairs on their biology. Methods Eph/Ephrin expression was analyzed in both BM-MSC and Ad-MSC by qRT-PCR. Then, we supplied BM-MSC cultures with either blocking or activating compounds to evaluate their effects on MSC proliferation, survival, and cell cycle by FACS. Changes in cytoskeleton and integrin α5β1 expression were studied in stimulated BM-MSC by immunofluorescence microscopy and FACS, respectively. Results Higher numbers of Eph/Ephrin transcripts occurred in BM-MSC than in Ad-MSC. In addition, the blocking of Eph/Ephrin signaling correlated with decreased numbers of BM-MSC due to increased proportions of apoptotic cells in the cultures but without variations in the cycling cells. Unexpectedly, activation of Eph/Ephrin signaling by clustered Eph/Ephrin fusion proteins also resulted in increased proportions of apoptotic MSC. In this case, MSC underwent important morphological changes, associated with altered cytoskeleton and integrin α5β1 expression, which did not occur under the blocking conditions. Conclusions Taken together, these results suggest that Eph/Ephrin activation affects cell survival through alterations in cell attachment to culture plates, affecting the biology of BM-MSC. Electronic supplementary material The online version of this article (10.1186/s13287-018-0912-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- David Alfaro
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, C/ José Antonio Novais, 12, CP 28040, Madrid, Spain
| | - Agustín G Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, C/ José Antonio Novais, 12, CP 28040, Madrid, Spain.
| |
Collapse
|
7
|
Kou CTJ, Kandpal RP. Differential Expression Patterns of Eph Receptors and Ephrin Ligands in Human Cancers. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7390104. [PMID: 29682554 PMCID: PMC5851329 DOI: 10.1155/2018/7390104] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/11/2018] [Accepted: 01/22/2018] [Indexed: 12/20/2022]
Abstract
Eph receptors constitute the largest family of receptor tyrosine kinases, which are activated by ephrin ligands that either are anchored to the membrane or contain a transmembrane domain. These molecules play important roles in the development of multicellular organisms, and the physiological functions of these receptor-ligand pairs have been extensively documented in axon guidance, neuronal development, vascular patterning, and inflammation during tissue injury. The recognition that aberrant regulation and expression of these molecules lead to alterations in proliferative, migratory, and invasive potential of a variety of human cancers has made them potential targets for cancer therapeutics. We present here the involvement of Eph receptors and ephrin ligands in lung carcinoma, breast carcinoma, prostate carcinoma, colorectal carcinoma, glioblastoma, and medulloblastoma. The aberrations in their abundances are described in the context of multiple signaling pathways, and differential expression is suggested as the mechanism underlying tumorigenesis.
Collapse
Affiliation(s)
- Chung-Ting Jimmy Kou
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Raj P. Kandpal
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| |
Collapse
|
8
|
Targeted therapies in hematological malignancies using therapeutic monoclonal antibodies against Eph family receptors. Exp Hematol 2017; 54:31-39. [PMID: 28751189 DOI: 10.1016/j.exphem.2017.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/06/2017] [Accepted: 07/11/2017] [Indexed: 12/16/2022]
Abstract
The use of monoclonal antibodies (mAbs) and molecules derived from them has achieved considerable attention and success in recent years, establishing this mode of therapy as an important therapeutic strategy in many cancers, in particular hematological tumors. mAbs recognize cell surface antigens expressed on target cells and mediate their function through various mechanisms such as antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, or immune system modulation. The efficacy of mAb therapy can be improved when they are conjugated to a highly potent payloads, including cytotoxic drugs and radiolabeled isotopes. The Eph family of proteins has received considerable attention in recent years as therapeutic targets for treatment of both solid and hematological cancers. High expression of Eph receptors on cancer cells compared with low expression levels in normal adult tissues makes them an attractive candidate for cancer immunotherapy. In this review, we detail the modes of action of antibody-based therapies with a focus on the Eph family of proteins as potential targets for therapy in hematological malignancies.
Collapse
|
9
|
García-Ceca J, Alfaro D, Montero-Herradón S, Tobajas E, Muñoz JJ, Zapata AG. Eph/Ephrins-Mediated Thymocyte-Thymic Epithelial Cell Interactions Control Numerous Processes of Thymus Biology. Front Immunol 2015; 6:333. [PMID: 26167166 PMCID: PMC4481163 DOI: 10.3389/fimmu.2015.00333] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/15/2015] [Indexed: 12/20/2022] Open
Abstract
Numerous studies emphasize the relevance of thymocyte-thymic epithelial cell (TECs) interactions for the functional maturation of intrathymic T lymphocytes. The tyrosine kinase receptors, Ephs (erythropoietin-producing hepatocyte kinases) and their ligands, ephrins (Eph receptor interaction proteins), are molecules known to be involved in the regulation of numerous biological systems in which cell-to-cell interactions are particularly relevant. In the last years, we and other authors have demonstrated the importance of these molecules in the thymic functions and the T-cell development. In the present report, we review data on the effects of Ephs and ephrins in the functional maturation of both thymic epithelial microenvironment and thymocyte maturation as well as on their role in the lymphoid progenitor recruitment into the thymus.
Collapse
Affiliation(s)
- Javier García-Ceca
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | - David Alfaro
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | - Sara Montero-Herradón
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | - Esther Tobajas
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | - Juan José Muñoz
- Cytometry and Fluorescence Microscopy Center, Complutense University, Madrid, Spain
| | - Agustín G. Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
- Cytometry and Fluorescence Microscopy Center, Complutense University, Madrid, Spain
| |
Collapse
|
10
|
O'Neal WT, Griffin WF, Dries-Devlin JL, Kent SD, Chen J, Willis MS, Virag JAI. Ephrin-Eph signaling as a potential therapeutic target for the treatment of myocardial infarction. Med Hypotheses 2013; 80:738-44. [PMID: 23562676 DOI: 10.1016/j.mehy.2013.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 01/27/2013] [Accepted: 02/28/2013] [Indexed: 01/22/2023]
Abstract
Although numerous strategies have been developed to reduce the initial ischemic insult and cellular injury that occurs during myocardial infarction (MI), few have progressed into the clinical arena. The epidemiologic and economic impact of MI necessitates the development of innovative therapies to rapidly and effectively reduce the initial injury and subsequent cardiac dysfunction. The Eph receptors and their cognate ligands, the ephrins, are the largest family of receptor tyrosine kinases, and their signaling has been shown to play a diverse role in various cellular processes. The recent advances in the study of ephrin-Eph signaling have shown promising progress in many fields of medicine. They have been implicated in the pathophysiology of various cancers and in the regulation of inflammation and apoptosis. Recent studies have shown that manipulation of ephrin-Eph cell signaling can favorably influence cardiomyocyte viability and ultimately preserve cardiac function post-MI. In this article, we explore the hypothesis that manipulation of ephrin-Eph signaling may potentially be a novel therapeutic target in the treatment of MI through alteration of the cellular processes that govern injury and wound healing.
Collapse
Affiliation(s)
- Wesley T O'Neal
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Eph/ephrinB signalling is involved in the survival of thymic epithelial cells. Immunol Cell Biol 2012; 91:130-8. [PMID: 23146940 DOI: 10.1038/icb.2012.59] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The signals that determine the survival/death of the thymic epithelial cells (TECs) component during embryonic development of the thymus are largely unknown. In this study, we combine different in vivo and in vitro experimental approaches to define the role played by the tyrosine kinase receptors EphB2 and EphB3 and their ligands, ephrinsB, in the survival of embryonic and newborn (NB) TECs. Our results conclude that EphB2 and EphB3 are involved in the control of TEC survival and that the absence of these molecules causes increased apoptotic TEC proportions that result in decreased numbers of thymic cells and a smaller-sized gland. Furthermore, in vitro studies using either EphB2-Fc or ephrinB1-Fc fusion proteins demonstrate that the blockade of Eph/ephrinB signalling increases TEC apoptosis, whereas its activation rescues TECs from cell death. In these assays, both heterotypic thymocyte-TEC and homotypic TEC-TEC interactions are important for Eph/ephrinB-mediated TEC survival.
Collapse
|
12
|
Mendes-da-Cruz DA, Stimamiglio MA, Muñoz JJ, Alfaro D, Terra-Granado E, Garcia-Ceca J, Alonso-Colmenar LM, Savino W, Zapata AG. Developing T-cell migration: role of semaphorins and ephrins. FASEB J 2012; 26:4390-9. [PMID: 22815386 DOI: 10.1096/fj.11-202952] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cell migration is a crucial event for normal T-cell development, and various ligand/receptor pairs have been implicated. Most of them, including chemokines and extracellular matrix proteins, have attractant properties on thymocytes. We discuss herein two further groups of ligand/receptor pairs, semaphorins/neuropilins and ephs/ephrins, which are constitutively expressed by thymocytes and thymic microenvironmental cells. Evidence shows that the corresponding interactions are relevant for developing T-cell migration, including the entry of bone marrow progenitor cells, migration of CD4/CD8-defined thymocyte subpopulations triggered by chemokines and/or extracellular matrix proteins, and thymocyte export. Conceptually, the data summarized here show that thymocyte migration results from a complex network of molecular interactions, which generate not only attraction, but also repulsion of migrating T-cell precursors.
Collapse
|
13
|
Kawano H, Katayama Y, Minagawa K, Shimoyama M, Henkemeyer M, Matsui T. A novel feedback mechanism by Ephrin-B1/B2 in T-cell activation involves a concentration-dependent switch from costimulation to inhibition. Eur J Immunol 2012; 42:1562-72. [PMID: 22622783 DOI: 10.1002/eji.201142175] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 01/25/2012] [Accepted: 02/16/2012] [Indexed: 11/10/2022]
Abstract
Bidirectional signals via Eph receptors/ephrins have been recognized as major forms of contact-dependent cell communications such as cell attraction and repulsion. T cells express EphBs, and their ligands, the ephrin-Bs, have been known as costimulatory molecules for T-cell proliferation. Recently, another remarkable feature of ephrin-As has emerged in the form of a concentration-dependent transition from promotion to inhibition in axon growth. Here we examined whether this modification plays a role in ephrin-B costimulation in murine primary T cells. Low doses of ephrin-B1 and ephrin-B2 costimulated T-cell proliferation induced by anti-CD3, but high concentrations strongly inhibited it. In contrast, ephrin-B3 showed a steadily increasing stimulatory effect. This modulation was virtually preserved in T cells from mice simultaneously lacking four genes, EphB1, EphB2, EphB3, and EphB6. High concentrations of ephrin-B1/B2, but not ephrin-B3, inhibited the anti-CD3-induced phosphorylation of Lck and its downstream signals such as Erk and Akt. Additionally, high doses of any ephrin-Bs could phosphorylate EphB4. However, only ephrin-B1/B2 but not ephrin-B3 recruited SHP1, a phosphatase to suppress the phosphorylation of Lck. These data suggest that EphB4 signaling could engage in negative feedback to TCR signals. T-cell activation may be finely adjusted by the combination and concentration of ephrin-Bs expressed in the immunological microenvironment.
Collapse
Affiliation(s)
- Hiroki Kawano
- Hematology, Department of Medicine, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan
| | | | | | | | | | | |
Collapse
|
14
|
The neuroimmune guidance cue netrin-1 promotes atherosclerosis by inhibiting the emigration of macrophages from plaques. Nat Immunol 2012; 13:136-43. [PMID: 22231519 PMCID: PMC3262880 DOI: 10.1038/ni.2205] [Citation(s) in RCA: 270] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 12/05/2011] [Indexed: 12/13/2022]
Abstract
Atherosclerotic plaque formation is fueled by the persistence of lipid-laden macrophages in the artery wall. The mechanisms by which these cells become trapped, thereby establishing chronic inflammation, remain unknown. Netrin-1, a neuroimmune guidance cue, was secreted by macrophages in human and mouse atheroma, where it inactivated macrophage migration to chemokines implicated in their egress from plaques. Acting via its receptor UNC5b, netrin-1 inhibited CCL2- and CCL19-directed macrophage migration, Rac1 activation and actin polymerization. Targeted deletion of netrin-1 in macrophagesseverely diminished atherosclerosis progression in Ldlr−/− mice and promoted macrophage emigration from plaques. Thus, netrin-1 promotes atherosclerosis by retaining macrophages in the artery wall and establish a causative role for negative regulators of leukocyte migration in chronic inflammation.
Collapse
|
15
|
Dzhagalov I, Phee H. How to find your way through the thymus: a practical guide for aspiring T cells. Cell Mol Life Sci 2011; 69:663-82. [PMID: 21842411 DOI: 10.1007/s00018-011-0791-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 07/25/2011] [Accepted: 07/25/2011] [Indexed: 01/16/2023]
Abstract
Thymocytes must complete an elaborate developmental program in the thymus to ultimately generate T cells that express functional but neither harmful nor useless TCRs. Each developmental step coincides with dynamic relocation of the thymocytes between anatomically discrete thymic microenvironments, suggesting that thymocytes' migration is tightly regulated by their developmental status. Chemokines produced by thymic stromal cells and chemokine receptors on the thymocytes play an indispensable role in guiding developing thymocytes into the different microenvironments. In addition to long-range migration, chemokines increase the thymocytes' motility, enhancing their interaction with stromal cells. During the past several years, much progress has been made to determine the various signals that guide thymocytes on their journey within the thymus. In this review, we summarize the progress in identifying chemokines and other chemoattractant signals that direct intrathymic migration. Furthermore, we discuss the recent advances of two-photon microscopy in determining dynamic motility and interaction behavior of thymocytes within distinct compartments to provide a better understanding of the relationship between thymocyte motility and development.
Collapse
Affiliation(s)
- Ivan Dzhagalov
- LSA, Room 479, Department of Molecular and Cell Biology, Division of Immunology and Pathogenesis, University of California Berkeley, Berkeley, CA 94720-3200, USA.
| | | |
Collapse
|
16
|
Alfaro D, Muñoz JJ, García‐Ceca J, Cejalvo T, Jiménez E, Zapata AG. The Eph/ephrinB signal balance determines the pattern of T‐cell maturation in the thymus. Immunol Cell Biol 2011; 89:844-52. [DOI: 10.1038/icb.2010.172] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- David Alfaro
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid Madrid Spain
| | - Juan José Muñoz
- Microscopy and Cytometry Centre, Complutense University of Madrid Madrid Spain
| | - Javier García‐Ceca
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid Madrid Spain
| | - Teresa Cejalvo
- Microscopy and Cytometry Centre, Complutense University of Madrid Madrid Spain
| | - Eva Jiménez
- Department of Cell Biology, Faculty of Medicine, Complutense University of Madrid Madrid Spain
| | - Agustín G Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid Madrid Spain
| |
Collapse
|
17
|
EphB-ephrin-B2 interactions are required for thymus migration during organogenesis. Proc Natl Acad Sci U S A 2010; 107:13414-9. [PMID: 20616004 DOI: 10.1073/pnas.1003747107] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Thymus organogenesis requires coordinated interactions of multiple cell types, including neural crest (NC) cells, to orchestrate the formation, separation, and subsequent migration of the developing thymus from the third pharyngeal pouch to the thoracic cavity. The molecular mechanisms driving these processes are unclear; however, NC-derived mesenchyme has been shown to play an important role. Here, we show that, in the absence of ephrin-B2 expression on thymic NC-derived mesenchyme, the thymus remains in the cervical area instead of migrating into the thoracic cavity. Analysis of individual NC-derived thymic mesenchymal cells shows that, in the absence of ephrin-B2, their motility is impaired as a result of defective EphB receptor signaling. This implies a NC-derived cell-specific role of EphB-ephrin-B2 interactions in the collective migration of the thymic rudiment during organogenesis.
Collapse
|
18
|
Stimamiglio MA, Jiménez E, Silva-Barbosa SD, Alfaro D, García-Ceca JJ, Muñoz JJ, Cejalvo T, Savino W, Zapata A. EphB2-mediated interactions are essential for proper migration of T cell progenitors during fetal thymus colonization. J Leukoc Biol 2010; 88:483-94. [DOI: 10.1189/jlb.0210079] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
|
19
|
García-Ceca J, Jiménez E, Alfaro D, Cejalvo T, Muñoz JJ, Zapata AG. Cell-autonomous role of EphB2 and EphB3 receptors in the thymic epithelial cell organization. Eur J Immunol 2009; 39:2916-24. [DOI: 10.1002/eji.200939437] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
20
|
Muñoz JJ, García-Ceca J, Alfaro D, Stimamiglio MA, Cejalvo T, Jiménez E, Zapata AG. Organizing the Thymus Gland. Ann N Y Acad Sci 2009; 1153:14-9. [DOI: 10.1111/j.1749-6632.2008.03965.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
21
|
Muñoz JJ, Alfaro D, García-Ceca J, Cejalvo T, Stimamiglio MA, Jiménez E, Zapata AG. Eph and ephrin: Key molecules for the organization and function of the thymus gland. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s0213-9626(09)70024-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
22
|
Alonso-C LM, Trinidad EMA, de Garcillan B, Ballesteros M, Castellanos M, Cotillo I, Muñoz JJ, Zapata AG. Expression profile of Eph receptors and ephrin ligands in healthy human B lymphocytes and chronic lymphocytic leukemia B-cells. Leuk Res 2008; 33:395-406. [PMID: 18819711 DOI: 10.1016/j.leukres.2008.08.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 08/14/2008] [Accepted: 08/18/2008] [Indexed: 11/28/2022]
Abstract
Increasing information relates some Eph receptors and their ligands, ephrins (EFN), with the immune system. Herein, we found that normal B-cells from peripheral blood (PB) and lymph nodes (LN) showed a differential expression of certain Eph/EFN members, some of them being modulated upon in vitro stimulation including EFNA1, EFNA4, EphB6 and EphA10. In contrast, PB CLL B-cells showed a more heterogeneous Eph/EFN profile than their normal PB B-cell counterparts, expressing Eph/EFN members frequently found within the LN and activated B-cells, specially EFNA4, EphB6 and EphA10. Two of them, EphB6 and EFNA4 were further related with the clinical course of CLL patients. EphB6 expression correlated with a high content of ZAP-70 mRNA and a poor prognosis. High serum levels of a soluble EFNA4 isoform positively correlated with increasing peripheral blood lymphocyte counts and lymphadenopathy. These findings suggest that Eph/EFN might be relevant in normal B-cell biology and could represent new potential prognostic markers and therapeutic targets for CLL.
Collapse
Affiliation(s)
- Luis M Alonso-C
- Centro de Microscopia y Citometria, Universidad Complutense de Madrid (U.C.M.), Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Edwards CM, Mundy GR. Eph receptors and ephrin signaling pathways: a role in bone homeostasis. Int J Med Sci 2008; 5:263-72. [PMID: 18797510 PMCID: PMC2536716 DOI: 10.7150/ijms.5.263] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Accepted: 09/03/2008] [Indexed: 02/05/2023] Open
Abstract
The maintenance of bone homeostasis is tightly controlled, and largely dependent upon cellular communication between osteoclasts and osteoblasts, and the coupling of bone resorption to bone formation. This tight coupling is essential for the correct function and maintenance of the skeletal system, repairing microscopic skeletal damage and replacing aged bone. A range of pathologic diseases, including osteoporosis and cancer-induced bone disease, disrupt this coupling and cause subsequent alterations in bone homeostasis. Eph receptors and their associated ligands, ephrins, play critical roles in a number of cellular processes including immune regulation, neuronal development and cancer metastasis. Eph receptors are also expressed by cells found within the bone marrow microenvironment, including osteoclasts and osteoblasts, and there is increasing evidence to implicate this family of receptors in the control of normal and pathological bone remodeling.
Collapse
Affiliation(s)
- Claire M Edwards
- Vanderbilt Center for Bone Biology, Departments of Cancer Biology and Clinical Pharmacology/Medicine, Vanderbilt University, Nashville, TN 37232-0575, USA.
| | | |
Collapse
|
24
|
Miao H, Wang B. Eph/ephrin signaling in epithelial development and homeostasis. Int J Biochem Cell Biol 2008; 41:762-70. [PMID: 18761422 DOI: 10.1016/j.biocel.2008.07.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/13/2008] [Accepted: 07/01/2008] [Indexed: 11/16/2022]
Abstract
Eph receptors and ephrin ligands are widely expressed during embryonic development with well-defined functions in directing neuronal and vascular network formation. Over the last decade, evidence has mounted that Ephs and ephrins are also actively involved in prenatal and postnatal development of epithelial tissues. Their functions beyond developmental settings are starting to be recognized as well. The diverse functions of Eph/ephrin are largely related to the complementary expression pattern of the Eph receptors and corresponding ephrin ligands that are expressed in adjacent compartments, although overlapping expression pattern also exists in epithelial tissue. The interconnection between Ephs or ephrins and classical cell junctional molecules suggests they may function coordinately in maintaining epithelial structural integrity and homeostasis. This review will highlight cellular and molecular evidence in current literature that support a role of Eph/ephrin systems in regulating epithelial cell development and physiology.
Collapse
Affiliation(s)
- Hui Miao
- Rammelkamp Center for Research, MetroHealth Campus, Case Western Reserve University School of Medicine, 2500 MetroHealth Drive, Cleveland, OH 44109, United States
| | | |
Collapse
|
25
|
Alfaro D, Muñoz JJ, García-Ceca J, Cejalvo T, Jiménez E, Zapata A. Alterations in the thymocyte phenotype of EphB-deficient mice largely affect the double negative cell compartment. Immunology 2008; 125:131-43. [PMID: 18397270 DOI: 10.1111/j.1365-2567.2008.02828.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In the present study, we have analysed the phenotype of EphB2 and/or EphB3 deficient thymocytes confirming and extending previous studies on the role of this family of molecules in T-cell differentiation. In all mutant thymuses statistically significant reduced cell contents were observed. This reduction of thymic cellularity correlated with increased proportions of apoptotic cells, largely both double negative (DN; CD4- CD8-) and double positive (CD4+ CD8+) cells, and decreased proportions of DN cycling cells. Adult deficient thymuses also showed increased proportions of DN cells but not significant variations in the percentages of other thymocyte subsets. In absolute terms, the thymocyte number decreased significantly in all thymocyte compartments from the DN3 (CD44- CD25+) cell stage onward, without variations in the numbers of both DN1 (CD44+ CD25-) and DN2 (CD44+ CD25+) cells. Remarkably, all these changes also occurred from the 15-day fetal EphB2 and/or EphB3 deficient mice, suggesting that adult phenotype results from the gradual accumulations of defects appearing early in the thymus ontogeny. As a reflection of thymus condition, a reduction in the number of T lymphocytes occurred in the peripheral blood and mesenteric lymph nodes, but not in spleen, maintaining the proportions of T-cell subsets defined by CD4/CD8 marker expression, in all cases.
Collapse
Affiliation(s)
- David Alfaro
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | | | | | | | | | | |
Collapse
|
26
|
Alfaro D, García-Ceca JJ, Cejalvo T, Jiménez E, Jenkinson EJ, Anderson G, Muñoz JJ, Zapata A. EphrinB1-EphB signaling regulates thymocyte-epithelium interactions involved in functional T cell development. Eur J Immunol 2007; 37:2596-605. [PMID: 17668899 DOI: 10.1002/eji.200737097] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Eph and ephrin families are involved in numerous developmental processes. Recently, an increasing body of evidence has related these families with some aspects of T cell development. In the present study, we show that the addition of either EphB2-Fc or ephrinB1-Fc fusion proteins to fetal thymus organ cultures established from 17-day-old fetal mice decreases the numbers of both double-positive (CD4(+)CD8(+)) and single-positive (both CD4(+)CD8(-) and CD4(-)CD8(+)) thymocytes, in correlation with increased apoptosis. By using reaggregate thymus organ cultures formed by fetal thymic epithelial cells (TEC) and CD4(+)CD8(+) thymocytes, we have also demonstrated that ephrinB1-Fc proteins are able to disorganize the three-dimensional epithelial network that in vivo supports the T cell maturation, and to alter the thymocyte interactions. In addition, in an in vitro model, Eph/ephrinB-Fc treatment also decreases the formation of cell conjugates by CD4(+)CD8(+) thymocytes and TEC as well as the TCR-dependent signaling between both cell types. Finally, immobilized EphB2-Fc and ephrinB1-Fc modulate the anti-CD3 antibody-induced apoptosis of CD4(+)CD8(+) thymocytes in a process dependent on concentration. These results therefore support a role for Eph/ephrinB in the processes of development and selection of thymocytes as well as in the establishment of the three-dimensional organization of TEC.
Collapse
Affiliation(s)
- David Alfaro
- Department of Cell Biology, Faculty of Biology, Complutense University, Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
We have previously demonstrated that binding of ephrin-A1 to Eph receptors on human CD4+ T cells stimulates migration. Here, we show that a distinct population of CD8+ T lymphocytes, expressing the chemokine receptor CCR7, also binds ephrin-A1 and is stimulated to migrate after binding. The Eph receptor signaling pathway taking part in the migration event was here investigated. Induced tyrosine phosphorylation of several proteins was seen after ephrin-A1 binding. In particular, induced phosphorylation and kinase activity of the Src kinase family member Lck was observed. An Lck inhibitor inhibited ephrin-A1-induced migration, indicating the involvement of Lck in the migration event. In addition, we observed an induced association of the focal adhesion-like kinase proline-rich tyrosine kinase 2 (Pyk2) and the guanidine exchange factor Vav1 with Lck. PI3K inhibitors also inhibited migration, and studies in transfectants indicate an association of PI3K with EphA1. Further, ephrin-A1-induced migration could be related to the activation of Rho GTPases. This was also observed by using an inhibitor of the Rho-associated kinase ROCK, a downstream effector of Rho. Our results suggest that stimulation of Eph receptors on CD8+CCR7+ T cells leads to migration involving activation of Lck, Pyk2, PI3K, Vav1 and Rho GTPase.
Collapse
Affiliation(s)
- Hanne S Hjorthaug
- Department of Immunology, Institute for Cancer Research, Rikshospitalet-Radiumhopitalet Medical Center, and Department of Medical Genetics, Ullevål University Hospital, Oslo, Norway
| | | |
Collapse
|
28
|
Pfaff D, Fiedler U, Augustin HG. Emerging roles of the Angiopoietin-Tie and the ephrin-Eph systems as regulators of cell trafficking. J Leukoc Biol 2006; 80:719-26. [PMID: 16864601 DOI: 10.1189/jlb.1105652] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Vascular receptor tyrosine kinases (RTK) have been identified as critical regulatory signaling molecules of developmental and adult vascular morphogenic processes [vascular endothelial growth factor (VEGF) receptors=sprouting; EphB receptors=assembly; Tie2 receptor=maturation and quiescence]. It is intriguing that the same molecules that control the growth of blood and lymphatic vessels play critical roles in the adult to regulate maintenance functions related to vascular homeostasis. VEGF is among the most potent inducers of vascular permeability. The second vascular RTK system, the interaction of paracrine-acting Angiopoietin-1 with its cognate receptor Tie2, acts as an endothelial maintenance and survival-mediating molecular system, which stabilizes the vessel wall and controls endothelial cell quiescence. The third vascular RTK system, the interaction of Eph receptors with their Eph family receptor-interacting protein (ephrin) ligands, transduces positional guidance cues on outgrowing vascular sprouts, which are critical for proper arteriovenous assembly and establishment of blood flow. As such, Eph-ephrin interactions act as an important regulator of cell-cell interactions, exerting propulsive and repulsive functions on neighboring cells and mediating adhesive functions. This review summarizes recent findings related to the roles of the Angiopoietin-Tie and the Eph-ephrin systems as regulators of cell trafficking in the vascular system. The recognition of vascular homeostatic functions of vascular RTKs marks an important change of paradigm in the field of angiogenesis research as it relates angiogenesis-inducing molecules to vascular maintenance functions in the adult. This may also broaden the scope of vascular RTK-targeted therapies.
Collapse
Affiliation(s)
- Dennis Pfaff
- Department of Vascular Oncology and Metastasis, University of Heidelberg, Germany
| | | | | |
Collapse
|
29
|
Muñoz JJ, Alfaro D, García-Ceca J, Alonso-C LM, Jiménez E, Zapata A. Thymic Alterations in EphA4-Deficient Mice. THE JOURNAL OF IMMUNOLOGY 2006; 177:804-13. [DOI: 10.4049/jimmunol.177.2.804] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
30
|
Abstract
Eph kinases are the largest family of receptor tyrosine kinases, and their ligands, ephrins (EFNs), are also cell surface molecules. In this study, we investigated the role of EFNB1 and the Ephs it interacts with (collectively called EFNB1 receptors) in mouse T-cell development. In the thymus, CD8 single positive (SP) and CD4CD8 double positive (DP) cells expressed high levels of EFNB1 and EFNB1 receptors, whereas CD4 SP cells had moderate expression of both. Soluble EFNB1-Fc in fetal thymus organ culture caused significant subpopulation ratio skew, with increased CD4 SP and CD8 SP and decreased DP percentage, while the cellularity of the thymus remained constant. Moreover, in EFNB1-treated fetal thymus organ culture, CD117(+), CD25(+), DP, CD4 SP, and CD8 SP cells all had significantly enhanced proliferation history, according to bromodeoxyuridine uptake. In vitro culture of isolated thymocytes revealed that EFNB1-Fc on solid-phase protected thymocytes from anti-CD3-induced apoptosis, with concomitant augmentation of several antiapoptotic factors, particularly in CD4 SP and CD8 SP cells; on the other hand, soluble EFNB1-Fc promoted anti-CD3-induced apoptosis, as was the case in vivo. This study reveals that EFNB1 and EFNB1 receptors are critical in thymocyte development.
Collapse
Affiliation(s)
- Guang Yu
- Laboratory of Immunology, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec H2L 4M1, Canada
| | | | | | | | | |
Collapse
|
31
|
Freywald A, Sharfe N, Miller CD, Rashotte C, Roifman CM. EphA Receptors Inhibit Anti-CD3-Induced Apoptosis in Thymocytes. THE JOURNAL OF IMMUNOLOGY 2006; 176:4066-74. [PMID: 16547242 DOI: 10.4049/jimmunol.176.7.4066] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The EphA receptor tyrosine kinases interact with membrane-bound ligands of the ephrin-A subfamily. Interaction induces EphA receptor oligomerization, tyrosine phosphorylation, and, as a result, EphA receptor signaling. EphA receptors have been shown to regulate cell survival, migration, and cell-cell and cell-matrix interactions. However, their functions in lymphoid cells are only beginning to be described. We show in this study that functional EphA receptors are expressed by murine thymocytes, including CD4(+)CD8(+), CD4(+)CD8(-), and CD4(-)CD8(+) subpopulations. We demonstrate that activation of EphA receptors by the ephrin-A1 ligand inhibits the anti-CD3-induced apoptosis of CD4(+)CD8(+) double-positive thymocytes. Furthermore, ephrin-A1 costimulation suppresses up-regulation of both the IL-2R alpha-chain (CD25) and early activation Ag CD69 and can block IL-2 production by CD4(+) single-positive cells. In agreement, EphA receptor activation in thymocytes also inhibits TCR-induced activation of the Ras-MAPK pathway. Our findings suggest that EphA receptor activation is antithetical to TCR signaling in thymocytes, and that the level of engagement by ephrin-A proteins on thymic APCs regulates thymocyte selection.
Collapse
MESH Headings
- Animals
- Antibodies/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Apoptosis/drug effects
- Apoptosis/immunology
- CD3 Complex/immunology
- Cells, Cultured
- Ephrin-A1/pharmacology
- Female
- Gene Expression Regulation
- Interleukin-2/metabolism
- Lectins, C-Type
- MAP Kinase Signaling System
- Mice
- Mice, Inbred BALB C
- Mitogen-Activated Protein Kinases/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Eph Family/immunology
- Receptors, Eph Family/metabolism
- Receptors, Interleukin-2/metabolism
- Thymus Gland/cytology
- Thymus Gland/drug effects
- Thymus Gland/immunology
- Thymus Gland/metabolism
- ras Proteins/metabolism
Collapse
Affiliation(s)
- Andrew Freywald
- Department of Chemistry and Biochemistry, University of Regina, Saskatchewan, Canada
| | | | | | | | | |
Collapse
|
32
|
Zapata A, Diez B, Cejalvo T, Gutiérrez-de Frías C, Cortés A. Ontogeny of the immune system of fish. FISH & SHELLFISH IMMUNOLOGY 2006; 20:126-36. [PMID: 15939627 DOI: 10.1016/j.fsi.2004.09.005] [Citation(s) in RCA: 360] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 09/03/2004] [Indexed: 05/02/2023]
Abstract
Information on the ontogeny of the fish immune system is largely restricted to a few species of teleosts (e.g., rainbow trout, catfish, zebrafish, sea bass) and has previously focused on morphological features. However, basic questions including the identification of the first lympho-hematopoietic sites, the origin of T- and B-lymphocytes and the acquisition of full immunological capacities remain to be resolved. We review these three main topics with special emphasis on recent results obtained from the zebrafish, a new experimental model particularly suitable for study of the ontogeny of the immune system because of its rapid development and easy manipulation. This species also provides an easy way of creating mutations that can be detected by various types of screens. In some teleosts (i.e., angelfish) the first blood cells are formed in the yolk sac. In others, such as zebrafish, the first hematopoietic site is an intraembryonic locus, the intermediate cell mass (ICM), whereas in both killifish and rainbow trout the first blood cells appear for a short time in the yolk sac but later the ICM becomes the main hematopoietic area. Erythrocytes and macrophages are the first blood cells to be identified in zebrafish embryos. They occur in the ICM, the duct of Cuvier and the peripheral circulation. Between 24 and 30 hour post-fertilization (hpf) at a temperature of 28 degrees C a few myeloblasts and myelocytes appear between the yolk sac and the body walls, and the ventral region of the tail of 1-2 day-old zebrafish also contains developing blood cells. The thymus, kidney and spleen are the major lymphoid organs of teleosts. The thymus is the first organ to become lymphoid, although earlier the kidney can contain hematopoietic precursors but not lymphocytes. In freshwater, but not in marine, teleosts the spleen is the last organ to acquire that condition. We and other authors have demonstrated an early expression of Rag-1 in the zebrafish thymus that correlates well with the morphological identification of lymphoid cells. On the other hand, the origins and time of appearance of B lymphocytes in teleosts are a matter of discussion and recent results are summarized here. The functioning rather than the mere morphological evidence of lymphocytes determines when the full immunocompetence in fish is attained. Information on the histogenesis of fish lymphoid organs can also be obtained by analysing zebrafish mutants with defects in the development of immune progenitors and/or in the maturation of non-lymphoid stromal elements of the lymphoid organs. The main characteristics of some of these mutants will also be described.
Collapse
Affiliation(s)
- A Zapata
- Department of Cell Biology, Faculty of Biology, Complutense University, 28040 Madrid, Spain.
| | | | | | | | | |
Collapse
|
33
|
Han L, Dong Z, Qiao Y, Kristensen GB, Holm R, Nesland JM, Suo Z. The clinical significance of EphA2 and Ephrin A-1 in epithelial ovarian carcinomas. Gynecol Oncol 2005; 99:278-86. [PMID: 16061279 DOI: 10.1016/j.ygyno.2005.06.036] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Revised: 05/30/2005] [Accepted: 06/03/2005] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To examine the expressions of the protein and mRNA of EPHA2 and EphrinA-1 in epithelial ovarian carcinomas/ovarian cancer cell lines and explore their prognostic value. METHODS To validate the immunohistochemical method, two ovarian cancer cell lines (OVCAR3 and SKOV3) were examined with RT-PCR, Western blot, and immunohistochemistry for EphA2 and EphrinA-1 expressions. Tumors from 118 patients with advanced epithelial ovarian cancer were then evaluated for EPHA2 and Ephrin A-1 protein expression, and frozen tissues from 30 cases were used for laser capture microdissection (LCM) assistant RT-PCR RNA analysis. RESULTS 11 (9.3%), 67 (56.8%), 26 (22.0%), and 14 (11.9%) tumors demonstrated negative, weak, moderate, and strong EphA2 protein expressions, respectively, while 3 (2.5%), 67 (56.8%), 32 (27.1%), and 16 (13.8%) tumors were negative, weak, moderate, and strong for Ephrin A-1 protein expression, respectively. Variable amount of mRNA expression was observed in the 30 tumors analyzed by the method of LCM assistant RT-PCR. There was a trend for association between higher levels of either EphA2 or Ephrin A-1 expression and higher histological grade (P = 0.05 for both factors). No significant correlation between the expressions of EphA2 or Ephrin A-1 and age, histological type, and FIGO stage was observed. Patients with higher levels of EphA2 protein expressions had significantly shorter survival. Cox multivariate analyses revealed that residual tumor after surgery, histological type, and EphA2 protein expression were of independent prognostic significance. CONCLUSIONS High level of EphA2 protein expression is significantly associated with a shorter patient survival and EphA2 receptor is a valuable prognostic marker for ovarian carcinoma.
Collapse
Affiliation(s)
- Liping Han
- Department of Pathology, The Norwegian Radium Hospital, University of Oslo, Montebello, 0310 Oslo, Norway
| | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
PURPOSE OF REVIEW This review summarizes recent knowledge on the role of receptor tyrosine kinases, particularly erythropoietin-producing hepatocyte kinases (Ephs), in T-cell function and development. RECENT FINDINGS Erythropoietin-producing hepatocyte kinase function and signaling in the immune system have been recently investigated. Cross-linking some Ephs results in T-cell costimulation and reduces the response threshold of T-cell receptor activation. In vivo, T-cell-mediated responses are compromised in EphB6-/- mice. Some Ephs are shown to control T-cell migration and adhesion, as well as the integrity of lymphoid organ structure. SUMMARY Ephs are the largest family of receptor tyrosine kinases. Some Ephs are expressed in the lymphoid organs. Ephrins, ligands of Ephs, are also cell surface molecules. Cross-linking of certain Ephs facilitates T-cell activation and proliferation. Under physiologic conditions, such cross-linking by ephrins likely occurs in lymphoid organs, where ephrins on T cells interact with ephrins on the surface of neighboring fraternal T cells or antigen-presenting cells; this may explain why T-cell responses are more effectively initiated in the lymphoid organs. Certain Ephs are also critical for lymphocyte adhesion and migration and for proper lymphoid organ structure. Ephs and ephrins are highly redundant and their interactions promiscuous, suggesting pivotal roles of these molecules in biology. Conversely, such redundancy represents a major challenge to further dissection of the function of individual Ephs. Multiple tissue-specific gene null mutations on Ephs or ephrins will likely reveal more interesting immune-related phenotypes.
Collapse
Affiliation(s)
- Jiangping Wu
- Laboratory of Immunology, Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Quebec H2L 4M1, Canada.
| | | |
Collapse
|
35
|
Luo H, Yu G, Tremblay J, Wu J. EphB6-null mutation results in compromised T cell function. J Clin Invest 2005; 114:1762-73. [PMID: 15599401 PMCID: PMC535066 DOI: 10.1172/jci21846] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 10/05/2004] [Indexed: 11/17/2022] Open
Abstract
So far, there is very limited knowledge about the role of Eph kinases, the largest family of receptor tyrosine kinases, in the immune system. Here, using EphB6(-/-) mice, we demonstrated that in vitro and in vivo T cell responses such as lymphokine secretion, proliferation, and the development of delayed-type skin hypersensitivity and experimental autoimmune encephalitis in EphB6(-/-) mice were compromised. On the other hand, humoral immune responses, such as serum levels of different Ig isotypes and IgG response to tetanus toxoid, were normal in these mice. Mechanistically, we showed that EphB6 migrated to the aggregated TCRs and rafts after TCR activation. Further downstream, in the absence of EphB6, ZAP-70 activation, LAT phosphorylation, the association of PLCgamma1 with SLP-76, and p44/42 MAPK activation were diminished. Thus, we have shown that EphB6 is pivotal in T cell function.
Collapse
MESH Headings
- Animals
- Antigens/metabolism
- Antigens, CD/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Biotinylation
- CD28 Antigens/biosynthesis
- CD3 Complex/biosynthesis
- Cell Proliferation
- Cytokines/biosynthesis
- Dose-Response Relationship, Drug
- Exons
- Female
- Flow Cytometry
- Gene Deletion
- Green Fluorescent Proteins/metabolism
- Immunoglobulin Class Switching
- Lectins, C-Type
- Leukocytes/metabolism
- Ligands
- Lymphocytes/metabolism
- Mice
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Models, Genetic
- Mutation
- Polymerase Chain Reaction
- Receptor, EphB6/genetics
- Receptor, EphB6/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Interleukin-2/biosynthesis
- Signal Transduction
- Spleen/metabolism
- T-Lymphocytes/metabolism
- Thymus Gland/metabolism
- Time Factors
Collapse
Affiliation(s)
- Hongyu Luo
- Laboratory of Immunology, Centre de Recherché, Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Pavilion DeSève, 1560 Sherbrooke Street East, Montréal, Quebec H2L 4M1, Canada
| | | | | | | |
Collapse
|
36
|
Sobel RA. Ephrin A receptors and ligands in lesions and normal-appearing white matter in multiple sclerosis. Brain Pathol 2005; 15:35-45. [PMID: 15779235 PMCID: PMC8095972 DOI: 10.1111/j.1750-3639.2005.tb00098.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Complexes of the tyrosine kinase ephrin ligands (ephrins) and their receptors (Ephs) provide critical cell recognition signals in CNS development. Complementary ephrin/Eph expression gradients present topographic guidance cues that may either stimulate or repulse axon growth. Some ephrin/Ephs are upregulated in adult CNS injury models. To assess their involvement in multiple sclerosis (MS), ephrin A1-5 and Eph A1-8 expression was analyzed in CNS tissues using immunohistochemistry. Control samples showed distinct expression patterns for each ephrin/Eph on different cell types. Perivascular mononuclear inflammatory cells, reactive astrocytes and macrophages expressed ephrin A1-4, Eph A1, -A3, -A4, -A6 and -A7 in active MS lesions. Axonal ephrin A1 and Eph A3, -A4, and -A7 expression was increased in active lesions and was greater in normal-appearing white matter (NAWM) adjacent to active lesions than within or adjacent to chronic MS lesions, in contralateral NAWM, or in control samples. As in development, therefore, there are temporally dynamic, lesion-associated axonal ephrin/Eph A expression gradients in the CNS of MS patients. These results indicate that ephrin/Eph As are useful cell markers in human CNS tissue samples; they likely are involved in the immunopathogenesis of active lesions and in neurodegeneration in MS NAWM; and they represent potential therapeutic targets in MS.
Collapse
Affiliation(s)
- Raymond A Sobel
- Laboratory Service, Veterans Affairs Health Care System, Palo Alto, California 94304, USA.
| |
Collapse
|
37
|
Yu G, Luo H, Wu Y, Wu J. EphrinB1 Is Essential in T-cell-T-cell Co-operation during T-cell Activation. J Biol Chem 2004; 279:55531-9. [PMID: 15502157 DOI: 10.1074/jbc.m410814200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eph kinases are the largest family of receptor tyrosine kinases, and their ligands are ephrins (EFNs), which are also cell surface molecules. We have very limited knowledge about the expression and function of these kinases and their ligands in the immune system. In this study we investigated the effect of EFNB1 on mouse T-cells. EFNB1 and the Eph kinases it interacts with (collectively called EFNB1 receptors (EFNB1R)) were expressed on T-cells, B cells, and monocytes/macrophages. Some T-cells were double positive for EFNB1 and EFBB1R. Solid phase EFNB1 in the presence of suboptimal TCR ligation augmented T-cell responses in terms interferon-gamma secretion, proliferation, and cytotoxic T lymphocyte activity but not interleukin-2 production. After T-cell receptor (TCR) ligation, EFNB1R congregated to TCR caps, and then both of them translocated to raft caps. This provides a morphological basis for EFNB1R to enhance TCR signaling. Further downstream of the signaling pathway, EFNB1R stimulation led to increased LAT (linker for activation of T-cells) phosphorylation and p44/42 and p38 MAPK activation. Similar to CD28 costimulation, EFNB1R costimulation was insensitive to cyclosporin A inhibition. On the other hand, unlike the former, EFNB1R costimulation failed to activate Akt, which is essential in triggering interleukin-2 production. Our study suggests that EFNB1 is pivotal in T-cell-T-cell costimulation and in reducing T-cell response threshold to antigen stimulation.
Collapse
Affiliation(s)
- Guang Yu
- Laboratory of Immunology, Notre-Dame Hospital, Centre Hospitalier de l'Universite de Montreal, Pavilion DeSève, 1560 Sherbrooke Street East, Montreal H2L 4M1, Quebec, Canada
| | | | | | | |
Collapse
|
38
|
Munthe E, Finne EF, Aasheim HC. Expression and functional effects of Eph receptor tyrosine kinase A family members on Langerhans like dendritic cells. BMC Immunol 2004; 5:9. [PMID: 15176971 PMCID: PMC443508 DOI: 10.1186/1471-2172-5-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2003] [Accepted: 06/03/2004] [Indexed: 11/10/2022] Open
Abstract
Background The Eph receptors are the largest receptor tyrosine kinase family. Several family members are expressed in hematopoietic cells. Previously, the expression of a member of this family, EphA2, was identified on dendritic like cells in tonsils. We therefore specifically examined the expression of EphA2 on in vitro generated dendritic cells. Results In this study, expression of the EphA2 receptor was identified on in vitro generated Langerhans like dendritic cells compared to in vitro generated dendritic cells. We show that ligand induced engagement of the EphA2 receptor leads to receptor autophosphorylation indicating a functional receptor signaling pathway in these cells. We also observe phosphorylation and dephosphorylation of distinct proteins following ligand activation of EphA receptors. In co-stimulation assays, receptor-ligand interaction reduces the capacity of the Langerhans like dendritic cells to stimulate resting CD4+ T cells. Conclusion Engagement of EphA receptor tyrosine kinases on Langerhans like dendritic cells induces signaling as shown by tyrosine phosphorylation and dephosphorylation of distinct proteins. Furthermore this engagement renders the cells less capable of stimulating CD4+ T cells.
Collapse
Affiliation(s)
- Else Munthe
- Department of Immunology, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway
| | - Eivind Farmen Finne
- Department of Immunology, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway
| | | |
Collapse
|
39
|
Wohlfahrt JG, Karagiannidis C, Kunzmann S, Epstein MM, Kempf W, Blaser K, Schmidt-Weber CB. Ephrin-A1 suppresses Th2 cell activation and provides a regulatory link to lung epithelial cells. THE JOURNAL OF IMMUNOLOGY 2004; 172:843-50. [PMID: 14707054 DOI: 10.4049/jimmunol.172.2.843] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gene expression screening showed decreased ephrin-A1 expression in CD4+ T cells of asthma patients. Ephrin-A1 is the ligand of the Eph receptor family of tyrosine kinases, forming the largest family of receptor tyrosine kinases. Their immune regulatory properties are largely unknown. This study demonstrates significantly reduced ephrin-A1 expression in T cells of asthma patients using real time-PCR. Immunohistological analyses revealed strong ephrin-A1 expression in lung tissue and low expression in cortical areas of lymph nodes. It is absent in T cell/B cell areas of the spleen. Colocalization of ephrin-A1 and its receptors was found only in the lung, but not in lymphoid tissues. In vitro activation of T cells reduced ephrin-A1 at mRNA and protein levels. T cell proliferation, activation-induced, and IL-2-dependent cell death were inhibited by cross-linking ephrin-A1, and not by engagement of Eph receptors. However, anti-EphA1 receptor slightly enhances Ag-specific and polyclonal proliferation of PBMC cultures. Furthermore, activation-induced CD25 up-regulation was diminished by ephrin-A1 engagement. Ephrin-A1 engagement reduced IL-2 expression by 82% and IL-4 reduced it by 69%; the IFN-gamma expression remained unaffected. These results demonstrate that ephrin-A1 suppresses T cell activation and Th2 cytokine expression, while preventing activation-induced cell death. The reduced ephrin-A1 expression in asthma patients may reflect the increased frequency of activated T cells in peripheral blood. That the natural ligands of ephrin-A1 are most abundantly expressed in the lung may be relevant for Th2 cell regulation in asthma and Th2 cell generation by mucosal allergens.
Collapse
Affiliation(s)
- Jan G Wohlfahrt
- Swiss Institute of Allergy and Asthma Research, Obere Strasse 22, CH-7270 Davos, Switzerland
| | | | | | | | | | | | | |
Collapse
|
40
|
Zamoyska R, Lovatt M. Signalling in T-lymphocyte development: integration of signalling pathways is the key. Curr Opin Immunol 2004; 16:191-6. [PMID: 15023412 DOI: 10.1016/j.coi.2004.01.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
alpha beta T-cell development is restricted to the thymus. Interactions between developing lymphocytes and the thymic stroma, together with bone-marrow-derived monocytes and dendritic cells, are critical for proper development of the T-cell lineage. The developmental sequence through which T-cell progenitors pass on their way to maturity is well established, and can be followed by the sequential acquisition and/or removal of cell surface molecules. Using the combination of modern genetic manipulations, such as transgenesis, gene ablation (knockouts) and targeted mutagenesis (knock-ins), with the ever-improving conditional and inducible manipulation of gene expression, we are beginning to gain an understanding of how intercellular interactions can be relayed via intracellular signalling cascades to bring about nuclear re-organisation and the differentiated mature CD4(+) and CD8(+) subpopulations.
Collapse
Affiliation(s)
- Rose Zamoyska
- Molecular Immunology, National Institute for Medical Research, The Ridgeway, London NW7 1AA, UK.
| | | |
Collapse
|
41
|
Yu G, Luo H, Wu Y, Wu J. Mouse EphrinB3 Augments T-cell Signaling and Responses to T-cell Receptor Ligation. J Biol Chem 2003; 278:47209-16. [PMID: 13679370 DOI: 10.1074/jbc.m306659200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ephrins (EFN) are cell-surface ligands of Ephs, the largest family of cell-surface receptor tyrosine kinases. The function of EFNs in the immune system has not been well studied, although some EFNs and Ephs are expressed at high levels on certain leukocytes. We report here that EFNB3 and its receptors (collectively called EFNB3Rs, as EFNB3 binds to multiple EphBs) were expressed in peripheral T cells and monocytes/macrophages, with T cells being the dominant EFNB3+ and EFNB3R+ cell type. Solid-phase EFNB3-Fc in the presence of suboptimal anti-CD3 crosslinking enhanced T-cell responses in terms of proliferation, activation marker expression, interferon-gamma but not interleukin-2 production, and cytotoxic T-cell activity. EFNB3R costimulation in the presence of phorbol 12-myristate 13- acetate was insensitive to cyclosporin A, similar to CD28 costimulation, suggesting they might share a part of the signaling pathway. After crosslinking, T-cell receptor and EFNB3R congregated into aggregated rafts, and this provided a morphological basis for signaling pathways of T-cell receptor and EFNB3R to interact. Solid-phase EFNB3-Fc augmented p38 and p44/42 MAPK activation further downstream of the signaling pathway. These data suggest that EFNB3 is important in T-cell/T-cell and T-cell/antigen-presenting cell collaboration to enhance T-cell activation and function.
Collapse
Affiliation(s)
- Guang Yu
- Laboratory of Immunology and the Nephrology Service of Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Quebec H2L 4M1, Canada
| | | | | | | |
Collapse
|
42
|
Yu G, Luo H, Wu Y, Wu J. Ephrin B2 induces T cell costimulation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:106-14. [PMID: 12816988 DOI: 10.4049/jimmunol.171.1.106] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eph kinases form the largest family of receptor tyrosine kinases, and their ligands are ephrins (EFNs), which are cell surface proteins. Some Eph kinases and EFNs are expressed on T cells, B cells, and dendritic cells, but their functions in the immune system are largely unknown. In this study, we investigated the effect of EFNB2 on murine T cells. EFNB2 mRNA was expressed in the cortex of the thymus and white pulp of the spleen. At the protein level, it was expressed on T cells and monocytes/macrophages, but not on B cells. EFNB2Rs were expressed mainly on T cells. Solid-phase EFNB2 along with suboptimal anti-CD3 strongly stimulated T cell proliferation, with concomitant augmentation of IFN-gamma but not IL-2 or IL-4 secretion. The activity of cytotoxic T cells was also significantly enhanced in the presence of solid-phase EFNB2. These results indicate that EFNB2R cross-linking results in costimulation of T cells. EFNB2Rs were normally scattered on the T cell surface; after TCR cross-linking, they rapidly congregated to capped TCR complexes and then to patched rafts. This provides a morphological base for EFNB2Rs to participate in T cell costimulation. We also demonstrated that EFNB2R signaling led to augmented p38 and p44/42 mitogen-activated protein kinase activation. Our study shows that EFNB2 plays important roles in immune regulation.
Collapse
Affiliation(s)
- Guang Yu
- Laboratory of Immunology and. Nephrology Service, Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montreal, Canada
| | | | | | | |
Collapse
|
43
|
Sharfe N, Freywald A, Toro A, Roifman CM. Ephrin-A1 induces c-Cbl phosphorylation and EphA receptor down-regulation in T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:6024-32. [PMID: 12794130 DOI: 10.4049/jimmunol.170.12.6024] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eph receptor tyrosine kinases are expressed by T lineage cells, and stimulation with their ligands, the ephrins, has recently been shown to modulate T cell behavior. We show that ephrin-A1 stimulation of Jurkat T cells induces tyrosine phosphorylation of EphA3 receptors and cytoplasmic proteins, including the c-cbl proto-oncogene. Cbl phosphorylation was also observed in peripheral blood T cells. In contrast, stimulation of Jurkat cells with the EphB receptor ligand ephrin-B1 does not cause Cbl phosphorylation. EphA activation also induced Cbl association with Crk-L and Crk-II adapters, but not the related Grb2 protein. Induction of Cbl phosphorylation upon EphA activation appeared to be dependent upon Src family kinase activity, as Cbl phosphorylation was selectively abrogated by the Src family inhibitor 4-amino-5(4-chlorophenyl-7-(tert-butyl)pyrazolo[3,4-d]pyrimidine, while EphA phosphorylation was unimpaired. Ephrin-A1 stimulation of Jurkat cells was also found to cause down-regulation of endogenous EphA3 receptors from the cell surface and their degradation. In accordance with the role of Cbl as a negative regulator of receptor tyrosine kinases, overexpression of wild-type Cbl, but not its 70-Z mutant, was found to down-regulate EphA receptor expression. Receptor down-regulation could also be inhibited by blockage of Src family kinase activity. Our findings show that EphA receptors can actively signal in T cells, and that Cbl performs multiple roles in this signaling pathway, functioning to transduce signals from the receptors as well as regulating activated EphA receptor expression.
Collapse
Affiliation(s)
- Nigel Sharfe
- Immunology and Allergy, Department of Pediatrics, Research Institute, Hospital for Sick Children, and University of Toronto, Toronto, Canada
| | | | | | | |
Collapse
|
44
|
Fuller CL, Braciale VL, Samelson LE. All roads lead to actin: the intimate relationship between TCR signaling and the cytoskeleton. Immunol Rev 2003; 191:220-36. [PMID: 12614363 DOI: 10.1034/j.1600-065x.2003.00004.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Regardless of cell type, the regulation of the actin cytoskeleton is tightly linked to vital biological properties such as polarity, motility, cell-cell contact, exocytosis and proliferation. In the immune system, where rapid and efficient response to antigen-provoked stimuli is crucial, an overwhelming amount of data implicate the actin cytoskeleton and its regulators as central to immune function. Increasingly, the cytoskeleton is considered an essential amplification step in T cell receptor (TCR)-, costimulatory-, and integrin-mediated signaling. Advances in genetic manipulation and confocal imaging have led to a keener appreciation of the importance of TCR signal integration by the actin cytoskeleton. This review outlines recent advances in elucidating the regulation of T cell function through the actin cytoskeleton. We also examine intriguing parallels between the immune system and other models of cytoskeletal regulation.
Collapse
Affiliation(s)
- Claudette L Fuller
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-4255, USA
| | | | | |
Collapse
|
45
|
Vergara-Silva A, Schaefer KL, Berg LJ. Compartmentalized Eph receptor and ephrin expression in the thymus. Mech Dev 2002; 119 Suppl 1:S225-9. [PMID: 14516690 DOI: 10.1016/s0925-4773(03)00121-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The maturation of T cells is an intricate process involving the interaction of developing thymocytes with discrete microenvironments within the thymus. Numerous studies have indicated that distinct thymic compartments provide signals required for each stage of thymocyte maturation. In this study we performed a comprehensive analysis of the expression patterns of Eph-A receptors and ephrins-A in the thymus using in situ hybridization and reverse transcription-polymerase chain reaction, and show that expression of these molecules is highly compartmentalized. Based on these expression patterns and the known mechanisms of action of Eph receptor/ephrin interactions in other organs, these data suggest that differential Eph receptor expression on discrete subsets of thymic stromal cells may be important in establishing compartment boundaries and preventing intermingling of stromal cell subtypes. Further, together with chemotactic signals such as those provided by chemokines, regulated Eph receptor/ephrin expression on thymocytes may play a role in thymocyte migration.
Collapse
Affiliation(s)
- Andrea Vergara-Silva
- Department of Pathology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | | | | |
Collapse
|
46
|
Abstract
Eph receptor tyrosine kinases and their ligands, the ephrins, are known to play an important role in regulating cell migration and targeting in neuronal and endothelial cells. Recently, it has been shown that lymphoid cells also express Eph receptors, raising the possibility that Eph receptors may similarly regulate lymphocyte migration. Chemotaxis in response to soluble chemokine factors is an essential facet of T cell biology. We demonstrate here that T cell chemotaxis in response to both the stromal cell-derived factor (SDF)-1alpha and macrophage inflammatory protein 3beta chemokines is modulated by costimulation with ephrins. Both ephrin-A and ephrin-B ligands were found to modify the chemotactic responses of a T cell line and primary T cells. Ephrin-A1, in particular, strongly inhibited chemotaxis. In accordance with the tyrosine kinase activity of EphA receptors, ephrin-A1 stimulation induced rapid intracellular tyrosine phosphorylation in T cells. Although strongly inhibiting chemotaxis, ephrin-A1 costimulus did not affect many of the signaling events downstream of the SDF-1alpha receptor CXCR4, including calcium flux and activation of MAPK. Rather, ephrin-A1 altered the balance of small G protein activity in T cells. Ephrin-A1 stimulation prevented SDF-1alpha-induced activation of cdc42, while simultaneously inducing rho activation. Ultimately, ephrin-A1 was found to inhibit chemokine-induced actin polymerization, thereby blocking migration. Ubiquitous ephrin expression in vivo creates enormous potential for T cells to encounter these ligands, suggesting that Eph receptors and ephrins may be important regulators of T cell migration.
Collapse
Affiliation(s)
- Nigel Sharfe
- Division of Immunology and Allergy, Department of Pediatrics, Infection, Immunity, Injury and Repair Program, Research Institute, The Hospital for Sick Children and the University of Toronto, Toronto, Canada
| | | | | | | | | |
Collapse
|