1
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Johansen KH, Golec DP, Huang B, Park C, Thomsen JH, Preite S, Cannons JL, Garçon F, Schrom EC, Courrèges CJF, Veres TZ, Harrison J, Nus M, Phelan JD, Bergmeier W, Kehrl JH, Okkenhaug K, Schwartzberg PL. A CRISPR screen targeting PI3K effectors identifies RASA3 as a negative regulator of LFA-1-mediated adhesion in T cells. Sci Signal 2022; 15:eabl9169. [PMID: 35857633 PMCID: PMC9637254 DOI: 10.1126/scisignal.abl9169] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The integrin lymphocyte function-associated antigen 1 (LFA-1) helps to coordinate the migration, adhesion, and activation of T cells through interactions with intercellular adhesion molecule 1 (ICAM-1) and ICAM-2. LFA-1 is activated during the engagement of chemokine receptors and the T cell receptor (TCR) through inside-out signaling, a process that is partially mediated by phosphoinositide 3-kinase (PI3K) and its product phosphatidylinositol 3,4,5-trisphosphate (PIP3). To evaluate potential roles of PI3K in LFA-1 activation, we designed a library of CRISPR/single guide RNAs targeting known and potential PIP3-binding proteins and screened for effects on the ability of primary mouse T cells to bind to ICAM-1. We identified multiple proteins that regulated the binding of LFA-1 to ICAM-1, including the Rap1 and Ras GTPase-activating protein RASA3. We found that RASA3 suppressed LFA-1 activation in T cells, that its expression was rapidly reduced upon T cell activation, and that its activity was inhibited by PI3K. Loss of RASA3 in T cells led to increased Rap1 activation, defective lymph node entry and egress, and impaired responses to T-dependent immunization in mice. Our results reveal a critical role for RASA3 in T cell migration, homeostasis, and function.
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Affiliation(s)
- Kristoffer H Johansen
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Section of Experimental and Translational Immunology, Department of Health Technology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Dominic P Golec
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bonnie Huang
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chung Park
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julie H Thomsen
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Silvia Preite
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jennifer L Cannons
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fabien Garçon
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Edward C Schrom
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Tibor Z Veres
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Harrison
- Cardiovascular Division, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Meritxell Nus
- Cardiovascular Division, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - James D Phelan
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wolfgang Bergmeier
- Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - John H Kehrl
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Klaus Okkenhaug
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Pamela L Schwartzberg
- Cell Signaling and Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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2
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Fragliasso V, Tameni A, Inghirami G, Mularoni V, Ciarrocchi A. Cytoskeleton Dynamics in Peripheral T Cell Lymphomas: An Intricate Network Sustaining Lymphomagenesis. Front Oncol 2021; 11:643620. [PMID: 33928032 PMCID: PMC8076600 DOI: 10.3389/fonc.2021.643620] [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: 12/18/2020] [Accepted: 03/17/2021] [Indexed: 12/04/2022] Open
Abstract
Defects in cytoskeleton functions support tumorigenesis fostering an aberrant proliferation and promoting inappropriate migratory and invasive features. The link between cytoskeleton and tumor features has been extensively investigated in solid tumors. However, the emerging genetic and molecular landscape of peripheral T cell lymphomas (PTCL) has unveiled several alterations targeting structure and function of the cytoskeleton, highlighting its role in cell shape changes and the aberrant cell division of malignant T cells. In this review, we summarize the most recent evidence about the role of cytoskeleton in PTCLs development and progression. We also discuss how aberrant signaling pathways, like JAK/STAT3, NPM-ALK, RhoGTPase, and Aurora Kinase, can contribute to lymphomagenesis by modifying the structure and the signaling properties of cytoskeleton.
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Affiliation(s)
- Valentina Fragliasso
- Laboratory of Translational Research, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Annalisa Tameni
- Laboratory of Translational Research, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy.,Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Modena, Italy
| | - Giorgio Inghirami
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
| | - Valentina Mularoni
- Laboratory of Translational Research, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Alessia Ciarrocchi
- Laboratory of Translational Research, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
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3
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Kunimura K, Uruno T, Fukui Y. DOCK family proteins: key players in immune surveillance mechanisms. Int Immunol 2020; 32:5-15. [PMID: 31630188 PMCID: PMC6949370 DOI: 10.1093/intimm/dxz067] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/16/2019] [Indexed: 12/11/2022] Open
Abstract
Dedicator of cytokinesis (DOCK) proteins constitute a family of evolutionarily conserved guanine nucleotide exchange factors (GEFs) for the Rho family of GTPases. Although DOCK family proteins do not contain the Dbl homology domain typically found in other GEFs, they mediate the GTP–GDP exchange reaction through the DOCK homology region-2 (DHR-2) domain. In mammals, this family consists of 11 members, each of which has unique functions depending on the expression pattern and the substrate specificity. For example, DOCK2 is a Rac activator critical for migration and activation of leukocytes, whereas DOCK8 is a Cdc42-specific GEF that regulates interstitial migration of dendritic cells. Identification of DOCK2 and DOCK8 as causative genes for severe combined immunodeficiency syndromes in humans has highlighted their roles in immune surveillance. In addition, the recent discovery of a naturally occurring DOCK2-inhibitory metabolite has uncovered an unexpected mechanism of tissue-specific immune evasion. On the other hand, GEF-independent functions have been shown for DOCK8 in antigen-induced IL-31 production in helper T cells. This review summarizes multifaced functions of DOCK family proteins in the immune system.
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Affiliation(s)
- Kazufumi Kunimura
- Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan
| | - Takehito Uruno
- Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.,Research Center for Advanced Immunology, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan
| | - Yoshinori Fukui
- Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.,Research Center for Advanced Immunology, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan
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4
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Fray MA, Charpentier JC, Sylvain NR, Seminario MC, Bunnell SC. Vav2 lacks Ca 2+ entry-promoting scaffolding functions unique to Vav1 and inhibits T cell activation via Cdc42. J Cell Sci 2020; 133:jcs238337. [PMID: 31974114 PMCID: PMC7075049 DOI: 10.1242/jcs.238337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/06/2020] [Indexed: 12/16/2022] Open
Abstract
Vav family guanine nucleotide exchange factors (GEFs) are essential regulators of immune function. Despite their structural similarity, Vav1 promotes and Vav2 opposes T cell receptor (TCR)-induced Ca2+ entry. By using a Vav1-deficient Jurkat T cell line, we find that Vav1 facilitates Ca2+ entry via non-catalytic scaffolding functions that are encoded by the catalytic core of Vav1 and flanking linker regions. We implicate, in this scaffolding function, a previously undescribed polybasic motif that is strictly conserved in Vav1 and absent from Vav2 in tetrapods. Conversely, the catalytic activity of Vav2 contributes to the suppression of TCR-mediated Ca2+ entry. By performing an in vivo 'GEF trapping' assay in intact cells, we demonstrate that Cdc42 interacts with the catalytic surface of Vav2 but not Vav1, and that Vav1 discriminates Cdc42 from Rac1 via F56 (W56 in Rac1). Finally, the Cdc42-specific inhibitor ZCL278 and the shRNA-mediated suppression of Cdc42 each prevent the inhibition of TCR-induced Ca2+ entry by Vav2. These findings define stark differences in the functions of Vav1 and Vav2, and provide an explanation for the differential usage of these Vav isoforms by immune subpopulations.
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Affiliation(s)
- Michael A Fray
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - John C Charpentier
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Nicholas R Sylvain
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Maria-Cristina Seminario
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Stephen C Bunnell
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
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5
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Wang L, Qin W, Huo YJ, Li X, Shi Q, Rasko JEJ, Janin A, Zhao WL. Advances in targeted therapy for malignant lymphoma. Signal Transduct Target Ther 2020; 5:15. [PMID: 32296035 PMCID: PMC7058622 DOI: 10.1038/s41392-020-0113-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/10/2019] [Accepted: 12/17/2019] [Indexed: 12/24/2022] Open
Abstract
The incidence of lymphoma has gradually increased over previous decades, and it ranks among the ten most prevalent cancers worldwide. With the development of targeted therapeutic strategies, though a subset of lymphoma patients has become curable, the treatment of refractory and relapsed diseases remains challenging. Many efforts have been made to explore new targets and to develop corresponding therapies. In addition to novel antibodies targeting surface antigens and small molecular inhibitors targeting oncogenic signaling pathways and tumor suppressors, immune checkpoint inhibitors and chimeric antigen receptor T-cells have been rapidly developed to target the tumor microenvironment. Although these targeted agents have shown great success in treating lymphoma patients, adverse events should be noted. The selection of the most suitable candidates, optimal dosage, and effective combinations warrant further investigation. In this review, we systematically outlined the advances in targeted therapy for malignant lymphoma, providing a clinical rationale for mechanism-based lymphoma treatment in the era of precision medicine.
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Affiliation(s)
- Li Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China
- Pôle de Recherches Sino-Français en Science du Vivant et Génomique, Laboratory of Molecular Pathology, Shanghai, China
| | - Wei Qin
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China
| | - Yu-Jia Huo
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China
| | - Xiao Li
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China
| | - Qing Shi
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China
| | - John E J Rasko
- Gene & Stem Cell Therapy Program Centenary Institute, Sydney Medical School, University of Sydney, Camperdown, Australia
- Cell and Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Anne Janin
- Pôle de Recherches Sino-Français en Science du Vivant et Génomique, Laboratory of Molecular Pathology, Shanghai, China
- U1165 Inserm/Université Paris 7, Hôpital Saint Louis, Paris, France
| | - Wei-Li Zhao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Er Road, Shanghai, China.
- Pôle de Recherches Sino-Français en Science du Vivant et Génomique, Laboratory of Molecular Pathology, Shanghai, China.
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6
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Gaud G, Roncagalli R, Chaoui K, Bernard I, Familiades J, Colacios C, Kassem S, Monsarrat B, Burlet-Schiltz O, de Peredo AG, Malissen B, Saoudi A. The costimulatory molecule CD226 signals through VAV1 to amplify TCR signals and promote IL-17 production by CD4 + T cells. Sci Signal 2018; 11:11/538/eaar3083. [PMID: 29991650 DOI: 10.1126/scisignal.aar3083] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The activation of T cells requires the guanine nucleotide exchange factor VAV1. Using mice in which a tag for affinity purification was attached to endogenous VAV1 molecules, we analyzed by quantitative mass spectrometry the signaling complex that assembles around activated VAV1. Fifty VAV1-binding partners were identified, most of which had not been previously reported to participate in VAV1 signaling. Among these was CD226, a costimulatory molecule of immune cells. Engagement of CD226 induced the tyrosine phosphorylation of VAV1 and synergized with T cell receptor (TCR) signals to specifically enhance the production of interleukin-17 (IL-17) by primary human CD4+ T cells. Moreover, co-engagement of the TCR and a risk variant of CD226 that is associated with autoimmunity (rs763361) further enhanced VAV1 activation and IL-17 production. Thus, our study reveals that a VAV1-based, synergistic cross-talk exists between the TCR and CD226 during both physiological and pathological T cell responses and provides a rational basis for targeting CD226 for the management of autoimmune diseases.
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Affiliation(s)
- Guillaume Gaud
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France
| | - Romain Roncagalli
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, Inserm, CNRS, 13288 Marseille, France
| | - Karima Chaoui
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS UMR 5089, 31077 Toulouse Cedex, France
| | - Isabelle Bernard
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France
| | - Julien Familiades
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France
| | - Céline Colacios
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France
| | - Sahar Kassem
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France
| | - Bernard Monsarrat
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS UMR 5089, 31077 Toulouse Cedex, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS UMR 5089, 31077 Toulouse Cedex, France
| | - Anne Gonzalez de Peredo
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS UMR 5089, 31077 Toulouse Cedex, France
| | - Bernard Malissen
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, Inserm, CNRS, 13288 Marseille, France.,Centre d'Immunophénomique, Aix-Marseille Université, Inserm, CNRS, 13288 Marseille, France
| | - Abdelhadi Saoudi
- Centre de Physiopathologie de Toulouse Purpan, Université de Toulouse, CNRS, Inserm, Toulouse 31300, France.
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7
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Novel insights into the pathogenesis of T-cell lymphomas. Blood 2018; 131:2320-2330. [DOI: 10.1182/blood-2017-11-764357] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 04/09/2018] [Indexed: 12/11/2022] Open
Abstract
Abstract
T-cell lymphomas are a heterogeneous group of rare malignancies with overlapping clinical, immunologic, and histologic features. Recent advances in our understanding of T-cell differentiation based on gene expression profiling, next-generation sequencing, and transgenic mouse modeling studies have better elucidated the pathogenetic mechanisms underlying the diverse biology of T-cell lymphomas. These studies show that although genetic alterations in epigenetic modifiers are implicated in all subtypes of T-cell lymphomas, specific subtypes demonstrate enrichment for particular recurrent alterations targeting specific genes. In this regard, RHOA and TET2 alterations are prevalent in nodal T-cell lymphomas, particularly angioimmunoblastic T-cell lymphomas, peripheral T-cell lymphomas (PTCLs) not otherwise specified, and nodal PTCLs with T-follicular helper phenotype. JAK-STAT signaling pathways are mutationally activated in many extranodal T-cell lymphomas, such as natural killer/T-cell and hepatosplenic T-cell lymphomas. The functional significance of many of these genetic alterations is becoming better understood. Altogether these advances will continue to refine diagnostic criteria, improve prognostication, and identify novel therapeutic targets, resulting in improved outcomes for patient with T-cell lymphomas.
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8
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Ushijima M, Uruno T, Nishikimi A, Sanematsu F, Kamikaseda Y, Kunimura K, Sakata D, Okada T, Fukui Y. The Rac Activator DOCK2 Mediates Plasma Cell Differentiation and IgG Antibody Production. Front Immunol 2018; 9:243. [PMID: 29503648 PMCID: PMC5820292 DOI: 10.3389/fimmu.2018.00243] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/29/2018] [Indexed: 12/12/2022] Open
Abstract
A hallmark of humoral immune responses is the production of antibodies. This process involves a complex cascade of molecular and cellular interactions, including recognition of specific antigen by the B cell receptor (BCR), which triggers activation of B cells and differentiation into plasma cells (PCs). Although activation of the small GTPase Rac has been implicated in BCR-mediated antigen recognition, its precise role in humoral immunity and the upstream regulator remain elusive. DOCK2 is a Rac-specific guanine nucleotide exchange factor predominantly expressed in hematopoietic cells. We found that BCR-mediated Rac activation was almost completely lost in DOCK2-deficient B cells, resulting in defects in B cell spreading over the target cell-membrane and sustained growth of BCR microclusters at the interface. When wild-type B cells were stimulated in vitro with anti-IgM F(ab′)2 antibody in the presence of IL-4 and IL-5, they differentiated efficiently into PCs. However, BCR-mediated PC differentiation was severely impaired in the case of DOCK2-deficient B cells. Similar results were obtained in vivo when DOCK2-deficient B cells expressing a defined BCR specificity were adoptively transferred into mice and challenged with the cognate antigen. In addition, by generating the conditional knockout mice, we found that DOCK2 expression in B-cell lineage is required to mount antigen-specific IgG antibody. These results highlight important role of the DOCK2–Rac axis in PC differentiation and IgG antibody responses.
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Affiliation(s)
- Miho Ushijima
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Takehito Uruno
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.,Research Center for Advanced Immunology, Kyushu University, Fukuoka, Japan
| | - Akihiko Nishikimi
- Department of Biosciences, School of Science, Kitasato University, Sagamihara, Japan
| | - Fumiyuki Sanematsu
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Yasuhisa Kamikaseda
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Kazufumi Kunimura
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Daiji Sakata
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.,Research Center for Advanced Immunology, Kyushu University, Fukuoka, Japan
| | - Takaharu Okada
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Yoshinori Fukui
- Division of Immunogenetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.,Research Center for Advanced Immunology, Kyushu University, Fukuoka, Japan
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9
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Multi-color single-molecule tracking and subtrajectory analysis for quantification of spatiotemporal dynamics and kinetics upon T cell activation. Sci Rep 2017; 7:6994. [PMID: 28765585 PMCID: PMC5539329 DOI: 10.1038/s41598-017-06960-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/20/2017] [Indexed: 11/08/2022] Open
Abstract
The dynamic properties of molecules in living cells are attracting increasing interest. We propose a new method, moving subtrajectory analysis using single-molecule tracking, and demonstrate its utility in the spatiotemporal quantification of not only dynamics but also the kinetics of interactions using single-color images. Combining this technique with three-color simultaneous single-molecule imaging, we quantified the dynamics and kinetics of molecules in spatial relation to T cell receptor (TCR) microclusters, which trigger TCR signaling. CD3ε, a component of the TCR/CD3 complex, and CD45, a phosphatase positively and negatively regulating signaling, were each found in two mobility states: faster (associated) and slower (dissociated) states. Dynamics analysis suggests that the microclusters are loosely composed of heterogeneous nanoregions, possibly surrounded by a weak barrier. Kinetics analysis quantified the association and dissociation rates of interactions with the microclusters. The associations of both CD3ε and CD45 were single-step processes. In contrast, their dissociations were each composed of two components, indicating transient and stable associated states. Inside the microclusters, the association was accelerated, and the stable association was increased. Only CD45 showed acceleration of association at the microcluster boundary, suggesting specific affinity on the boundary. Thus, this method is an innovative and versatile tool for spatiotemporal quantification.
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10
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Zhu X, Jin H, Xia Z, Wu X, Yang M, Zhang H, Shang X, Cheng R, Zhan Z, Yu Z. Vav1 expression is increased in esophageal squamous cell carcinoma and indicates poor prognosis. Biochem Biophys Res Commun 2017; 486:571-576. [PMID: 28336434 DOI: 10.1016/j.bbrc.2017.03.091] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/18/2017] [Indexed: 01/16/2023]
Abstract
Recently, Vav1 has been suggested to play an essential role in the progression of human cancers. However, the correlation between Vav1 expression and prognosis of esophageal squamous cell carcinoma (ESCC) is still unknown. The aim of this study was to investigate Vav1 expression and its prognostic value in ESCC. The expression of Vav1 was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting in ESCC tissues and matched nontumorous tissues. Immunohistochemistry (IHC) was carried out to detect Vav1 expression in paraffin samples from 112 primary ESCC patients. Survival analysis was performed using Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to evaluate the correlation of Vav1 expression with prognosis of ESCC patients. The expression levels of Vav1 mRNA and protein in ESCC tissues were both significantly higher than those in adjacent nontumorous tissues. High Vav1 expression was significantly correlated with larger tumor size (P = 0.015), depth of tumor invasion (P = 0.023), lymph node metastasis (P = 0.008) and TNM stage (P < 0.001). The rate of overall survival (OS) was significantly lower in patients with high Vav1 expression than those with low Vav1 expression (P = 0.014). Multivariate Cox analysis indicated that Vav1 expression is an independent prognostic factor for OS (HR = 1.660, 95%CI = 1.058-2.607, P = 0.028). In summary, our findings demonstrate that Vav1 may be a candidate molecular prognostic marker for patients with ESCC.
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Affiliation(s)
- Xiaolei Zhu
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China; Department of Thoracic Surgery, Second Hospital of Tianjin Medical University, Tianjin 300060, China
| | - Huan Jin
- Department of Nursing, Second Hospital of Tianjin Medical University, Tianjin 300060, China
| | - Ziwei Xia
- Department of Thoracic Surgery, Second Hospital of Tianjin Medical University, Tianjin 300060, China
| | - Xianxian Wu
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Mingjian Yang
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Hongdian Zhang
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Xiaobin Shang
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Runfen Cheng
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Zhongli Zhan
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China
| | - Zhentao Yu
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin City, Tianjin 300060, China.
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11
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Boddicker RL, Razidlo GL, Feldman AL. Genetic alterations affecting GTPases and T-cell receptor signaling in peripheral T-cell lymphomas. Small GTPases 2017; 10:33-39. [PMID: 27898263 DOI: 10.1080/21541248.2016.1263718] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Peripheral T-cell lymphomas (PTCLs) are rare, heterogeneous tumors with poor response to standard therapy and few targeted treatments available. The identification of mutations in the T-cell receptor (TCR) signaling pathway that either directly or indirectly affect Ras- and Rho-family GTPases is an emerging theme across PTCL subtypes. This review summarizes the role of GTPases in TCR signaling and highlights the constellation of mutations in this pathway among PTCLs. In particular, focus is given to the functional impact of the mutations and opportunities for targeted therapy. These mutations include activating mutations and gene fusions involving the guanine nucleotide exchange factor, VAV1, as well as activating and dominant negative mutations in the GTPases KRAS and RHOA, respectively. In addition to mutations directly affecting the GTPase pathway, TCR signaling mutations indirectly affecting Ras- and Rho-family GTPases involving genes such as CD28, FYN, LCK, and PLCG1 are also reviewed.
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Affiliation(s)
- Rebecca L Boddicker
- a Department of Laboratory Medicine and Pathology , Mayo Clinic , Rochester , MN , USA
| | - Gina L Razidlo
- b Center for Basic Research in Digestive Diseases, Division of Gastroenterology & Hepatology, Mayo Clinic , Rochester , MN , USA.,c Department of Biochemistry and Molecular Biology , Mayo Clinic , Rochester , MN , USA
| | - Andrew L Feldman
- a Department of Laboratory Medicine and Pathology , Mayo Clinic , Rochester , MN , USA
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12
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TGFβ promotes mesenchymal phenotype of pancreatic cancer cells, in part, through epigenetic activation of VAV1. Oncogene 2016; 36:2202-2214. [PMID: 27893715 DOI: 10.1038/onc.2016.378] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/14/2016] [Accepted: 08/29/2016] [Indexed: 02/06/2023]
Abstract
The highly homeostasis-resistant nature of cancer cells leads to their escape from treatment and to liver metastasis, which in turn makes pancreatic ductal adenocarcinoma (PDAC) difficult to treat, especially the squamous/epithelial-to-mesenchymal transition (EMT)-like subtype. As the molecular mechanisms underlying tumour heterogeneity remain elusive, we investigated whether epigenetic regulation might explain inter-individual differences in the progression of specific subtypes. DNA methylation profiling performed on cancer tissues prior to chemo/radiotherapy identified one hypermethylated CpG site (CpG6882469) in the VAV1 gene body that was correlated with demethylation of two promoter CpGs (CpG6772370/CpG6772811) in both PDAC and peripheral blood. Transforming growth factor β treatment induced gene-body hypermethylation, dissociation of DNMT1 from the promoter, and VAV1 expression via SMAD4 and mutant KrasG12D. Pharmacological inhibition of TGFβ-VAV1 signalling decreased the squamous/EMT-like cancer cells, promoted nuclear VAV1 localization, and enhanced the efficacy of gemcitabine in prolonging the survival of KPfl/flC mice. Together, the three VAV1 CpGs serve as biomarkers for prognosis and early detection, and the TGFβ-VAV1 axis represents a therapeutic target.
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13
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Comrie WA, Burkhardt JK. Action and Traction: Cytoskeletal Control of Receptor Triggering at the Immunological Synapse. Front Immunol 2016; 7:68. [PMID: 27014258 PMCID: PMC4779853 DOI: 10.3389/fimmu.2016.00068] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/12/2016] [Indexed: 01/03/2023] Open
Abstract
It is well known that F-actin dynamics drive the micron-scale cell shape changes required for migration and immunological synapse (IS) formation. In addition, recent evidence points to a more intimate role for the actin cytoskeleton in promoting T cell activation. Mechanotransduction, the conversion of mechanical input into intracellular biochemical changes, is thought to play a critical role in several aspects of immunoreceptor triggering and downstream signal transduction. Multiple molecules associated with signaling events at the IS have been shown to respond to physical force, including the TCR, costimulatory molecules, adhesion molecules, and several downstream adapters. In at least some cases, it is clear that the relevant forces are exerted by dynamics of the T cell actomyosin cytoskeleton. Interestingly, there is evidence that the cytoskeleton of the antigen-presenting cell also plays an active role in T cell activation, by countering the molecular forces exerted by the T cell at the IS. Since actin polymerization is itself driven by TCR and costimulatory signaling pathways, a complex relationship exists between actin dynamics and receptor activation. This review will focus on recent advances in our understanding of the mechanosensitive aspects of T cell activation, paying specific attention to how F-actin-directed forces applied from both sides of the IS fit into current models of receptor triggering and activation.
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Affiliation(s)
- William A Comrie
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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14
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Helou YA, Petrashen AP, Salomon AR. Vav1 Regulates T-Cell Activation through a Feedback Mechanism and Crosstalk between the T-Cell Receptor and CD28. J Proteome Res 2015; 14:2963-75. [PMID: 26043137 DOI: 10.1021/acs.jproteome.5b00340] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Vav1, a Rac/Rho guanine nucleotide exchange factor and a critical component of the T-cell receptor (TCR) signaling cascade is tyrosine phosphorylated rapidly in response to T-cell activation. Vav1 has established roles in proliferation, cytokine secretion, Ca(2+) responses, and actin cytoskeleton regulation; however, its function in the regulation of phosphorylation of TCR components, including the ζ chain, the CD3 δ, ε, γ chains, and the associated kinases Lck and ZAP-70, is not well established. To obtain a more comprehensive picture of the role of Vav1 in receptor proximal signaling, we performed a wide-scale characterization of Vav1-dependent tyrosine phosphorylation events using quantitative phosphoproteomic analysis of Vav1-deficient T cells across a time course of TCR stimulation. Importantly, this study revealed a new function for Vav1 in the negative feedback regulation of the phosphorylation of immunoreceptor tyrosine-based activation motifs within the ζ chains, CD3 δ, ε, γ chains, as well as activation sites on the critical T cell tyrosine kinases Itk, Lck, and ZAP-70. Our study also uncovered a previously unappreciated role for Vav1 in crosstalk between the CD28 and TCR signaling pathways.
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Affiliation(s)
- Ynes A Helou
- †Department of Molecular Pharmacology, Physiology, and Biotechnology and ‡Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02903, United States
| | - Anna P Petrashen
- †Department of Molecular Pharmacology, Physiology, and Biotechnology and ‡Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02903, United States
| | - Arthur R Salomon
- †Department of Molecular Pharmacology, Physiology, and Biotechnology and ‡Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02903, United States
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15
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Grassilli S, Brugnoli F, Lattanzio R, Rossi C, Perracchio L, Mottolese M, Marchisio M, Palomba M, Nika E, Natali PG, Piantelli M, Capitani S, Bertagnolo V. High nuclear level of Vav1 is a positive prognostic factor in early invasive breast tumors: a role in modulating genes related to the efficiency of metastatic process. Oncotarget 2015; 5:4320-36. [PMID: 24962430 PMCID: PMC4147326 DOI: 10.18632/oncotarget.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Vav1 is one of the signalling proteins normally restricted to hematopoietic cells that results ectopically expressed in solid tumors, including breast cancer. By immunohistochemical analysis on TMAs containing invasive breast tumor from patients without lymph node involvement, we have found that Vav1 is expressed in almost all investigated cancers and shows a peculiar localization inside the nucleus of tumor cells. High amounts of nuclear Vav1 are positively correlated with low incidence of relapse, regardless phenotype and molecular subtype of breast neoplasia. In particular, Kaplan-Meier plots showed an elevated risk of distant metastasis in patients with low Vav1 expression compared with patients with high Vav1 expression in their tumors. Experiments performed with breast tumor-derived cells indicated that Vav1 negatively modulates their invasiveness in vitro and their metastatic efficiency in vivo, possibly by affecting the expression of genes involved in invasion and/or metastasis of breast tumors. Since the high heterogeneity of breast tumors makes difficult to predict the evolution of early breast neoplasias, the evaluation of nuclear Vav1 levels may help in the characterization and management of early breast cancer patients. In particular, Vav1 may serve as a prognostic biomarker and a target for new therapies aimed to prevent breast cancer progression.
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Affiliation(s)
- Silvia Grassilli
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy. These authors contributed equally to this work
| | - Federica Brugnoli
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy. These authors contributed equally to this work
| | - Rossano Lattanzio
- Department of Experimental and Clinical Sciences, University "G. d'Annunzio" Chieti, Italy. Center of Excellence for Research on Aging, Foundation University "G. d'Annunzio", Chieti, Italy
| | - Cosmo Rossi
- Center of Excellence for Research on Aging, Foundation University "G. d'Annunzio", Chieti, Italy. Department of Biomorphology, University "G. D'Annunzio" Chieti, Italy
| | | | | | - Marco Marchisio
- Center of Excellence for Research on Aging, Foundation University "G. d'Annunzio", Chieti, Italy. Department of Biomorphology, University "G. D'Annunzio" Chieti, Italy
| | - Maria Palomba
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Ervin Nika
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | | | - Mauro Piantelli
- Department of Experimental and Clinical Sciences, University "G. d'Annunzio" Chieti, Italy. Center of Excellence for Research on Aging, Foundation University "G. d'Annunzio", Chieti, Italy
| | - Silvano Capitani
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy. LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Valeria Bertagnolo
- Section of Anatomy and Histology, Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
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16
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Molecular mechanisms and functional implications of polarized actin remodeling at the T cell immunological synapse. Cell Mol Life Sci 2014; 72:537-556. [PMID: 25355055 DOI: 10.1007/s00018-014-1760-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 09/22/2014] [Accepted: 10/13/2014] [Indexed: 02/05/2023]
Abstract
Transient,specialized cell-cell interactions play a central role in leukocyte function by enabling specific intercellular communication in the context of a highly dynamic systems level response. The dramatic structural changes required for the formation of these contacts are driven by rapid and precise cytoskeletal remodeling events. In recent years, the immunological synapse that forms between a T lymphocyte and its antigen-presenting target cell has emerged as an important model system for understanding immune cell interactions. In this review, we discuss how regulators of the cortical actin cytoskeleton control synaptic architecture and in this way specify T cell function.
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17
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Wan YJ, Yang Y, Leng QL, Lan B, Jia HY, Liu YH, Zhang CZ, Cao Y. Vav1 increases Bcl-2 expression by selective activation of Rac2-Akt in leukemia T cells. Cell Signal 2014; 26:2202-9. [PMID: 24880064 DOI: 10.1016/j.cellsig.2014.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 01/06/2023]
Abstract
Vav proteins are guanine nucleotide exchange factors (GEFs) that activate a group of small G proteins (GTPases). Vav1 is predominantly expressed in hematopoietic cells, whereas Vav2 and Vav3 are ubiquitously distributed in almost all human tissues. All three Vav proteins contain conserved structural motifs and associate with a variety of cellular activities including proliferation, migration, and survival. Previous observation with Jurkat leukemia T cells showed that Vav1 possessed anti-apoptotic activity by enhancing Bcl-2 transcription. However the mechanism has not been unveiled. Here, we explored the effectors of Vav1 in promoting Bcl-2 expression in Jurkat cells and revealed that Rac2-Akt was specifically evoked by the expression of Vav1, but not Vav2 or Vav3. Although all three Vav isoforms existed in Jurkat cells, Rac2 was distinguishably activated by Vav1 and that led to enhanced Bcl-2 expression and cell survival. Akt was modulated downstream of Vav1-Rac2, and the activation of Akt was indispensable in the enhanced transcription of Bcl-2. Intriguingly, neither Vav2 nor Vav3 was able to activate Rac2-Akt pathway as determined by gene silencing approach. Our data illustrated a unique role of Vav1 in T leukemia survival by selectively triggering Rac2-Akt axis and elevating the expression of anti-apoptotic Bcl-2.
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Affiliation(s)
- Ya-Juan Wan
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Yin Yang
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Qian-Li Leng
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Bei Lan
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Hui-Yan Jia
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Yao-Hui Liu
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Cui-Zhu Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China
| | - Youjia Cao
- Key Laboratory of Microbial Functional Genomics of Ministry of Education, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China; State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, PR China.
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18
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Pham K, Sacirbegovic F, Russell SM. Polarized cells, polarized views: asymmetric cell division in hematopoietic cells. Front Immunol 2014; 5:26. [PMID: 24550912 PMCID: PMC3909886 DOI: 10.3389/fimmu.2014.00026] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/16/2014] [Indexed: 11/17/2022] Open
Abstract
It has long been recognized that alterations in cell shape and polarity play important roles in coordinating lymphocyte functions. In the last decade, a new aspect of lymphocyte polarity has attracted much attention, termed asymmetric cell division (ACD). ACD has previously been shown to dictate or influence many aspects of development in model organisms such as the worm and the fly, and to be disrupted in disease. Recent observations that ACD also occurs in lymphocytes led to exciting speculations that ACD might influence lymphocyte differentiation and function, and leukemia. Dissecting the role that ACD might play in these activities has not been straightforward, and the evidence to date for a functional role in lymphocyte fate determination has been controversial. In this review, we discuss the evidence to date for ACD in lymphocytes, and how it might influence lymphocyte fate. We also discuss current gaps in our knowledge, and suggest approaches to definitively test the physiological role of ACD in lymphocytes.
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Affiliation(s)
- Kim Pham
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre , East Melbourne, VIC , Australia ; Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology , Hawthorn, VIC , Australia
| | - Faruk Sacirbegovic
- Department of Pathology, University of Melbourne , Melbourne, VIC , Australia
| | - Sarah M Russell
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre , East Melbourne, VIC , Australia ; Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology , Hawthorn, VIC , Australia ; Department of Pathology, University of Melbourne , Melbourne, VIC , Australia ; Sir Peter MacCallum Department of Oncology, University of Melbourne , Melbourne, VIC , Australia
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19
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Razidlo GL, Schroeder B, Chen J, Billadeau DD, McNiven MA. Vav1 as a central regulator of invadopodia assembly. Curr Biol 2013; 24:86-93. [PMID: 24332539 DOI: 10.1016/j.cub.2013.11.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 09/20/2013] [Accepted: 11/04/2013] [Indexed: 01/08/2023]
Abstract
Invadopodia are protrusive structures used by tumor cells for degradation of the extracellular matrix to promote invasion [1]. Invadopodia formation and function are regulated by cytoskeletal-remodeling pathways and the oncogenic kinase Src. The guanine nucleotide exchange factor Vav1, which is an activator of Rho family GTPases, is ectopically expressed in many pancreatic cancers, where it promotes tumor cell survival and migration [2, 3]. We have now determined that Vav1 is also a potent regulator of matrix degradation by pancreatic tumor cells as depletion of Vav1 by siRNA-mediated knockdown inhibits the formation of invadopodia. This requires the exchange function of Vav1 toward the GTPase Cdc42, which is required for invadopodia assembly [4, 5]. In addition, we have determined that Src-mediated phosphorylation and activation of Vav1 are both required for, and, unexpectedly, sufficient for, invadopodia formation. Expression of Vav1 Y174F, which mimics its activated state, is a potent inducer of invadopodia formation through Cdc42, even in the absence of Src activation and phosphorylation of other Src substrates, such as cortactin. Thus, these data identify a novel mechanism by which Vav1 can enhance the tumorigenicity and invasive potential of cancer cells. These data suggest that Vav1 promotes the matrix-degrading processes underlying tumor cell migration and further, under conditions of ectopic Vav1 expression, that Vav1 is a central regulator and major driver of invasive matrix remodeling by pancreatic tumor cells.
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Affiliation(s)
- Gina L Razidlo
- Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, MN 55905, USA
| | - Barbara Schroeder
- Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, MN 55905, USA
| | - Jing Chen
- Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, MN 55905, USA
| | - Daniel D Billadeau
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA; Division of Oncology Research, Mayo Clinic, Rochester, MN 55905, USA
| | - Mark A McNiven
- Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, MN 55905, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA.
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20
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Le Floc'h A, Tanaka Y, Bantilan NS, Voisinne G, Altan-Bonnet G, Fukui Y, Huse M. Annular PIP3 accumulation controls actin architecture and modulates cytotoxicity at the immunological synapse. ACTA ACUST UNITED AC 2013; 210:2721-37. [PMID: 24190432 PMCID: PMC3832928 DOI: 10.1084/jem.20131324] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
In T cells, PI3K activation in the periphery of the immune synapse leads to PIP3 accumulation that promotes actin polymerization in a pathway important for cytotoxic function. The immunological synapse formed by a T lymphocyte on the surface of a target cell contains a peripheral ring of filamentous actin (F-actin) that promotes adhesion and facilitates the directional secretion of cytokines and cytolytic factors. We show that growth and maintenance of this F-actin ring is dictated by the annular accumulation of phosphatidylinositol trisphosphate (PIP3) in the synaptic membrane. PIP3 functions in this context by recruiting the exchange factor Dock2 to the periphery of the synapse, where it drives actin polymerization through the Rho-family GTPase Rac. We also show that synaptic PIP3 is generated by class IA phosphoinositide 3-kinases that associate with T cell receptor microclusters and are activated by the GTPase Ras. Perturbations that inhibit or promote PIP3-dependent F-actin remodeling dramatically affect T cell cytotoxicity, demonstrating the functional importance of this pathway. These results reveal how T cells use lipid-based signaling to control synaptic architecture and modulate effector responses.
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Affiliation(s)
- Audrey Le Floc'h
- Immunology Program, 2 Computational Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065
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21
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Abstract
Tight regulation of actin dynamics is essential for T-cell trafficking and activation. Recent studies in human and murine T cells reveal that T-cell motility and full T-cell activation require the hematopoietic-specific, actin-bundling protein L-plastin (LPL). T cells lacking LPL do not form fully mature synapses and thus demonstrate reduced cytokine production and proliferation. Reduction or loss of LPL expression also reduces the velocity of T cells and impairs thymic egress and intranodal motility. Whereas dispensable for proximal T-cell receptor and chemokine receptor signaling, LPL is critical to the later stages of synapse maturation and cellular polarization. Serine phosphorylation, calcium, and calmodulin binding regulate the bundling activity and localization of LPL following T-cell receptor and chemokine receptor engagement. However, the interaction between these regulatory domains and resulting changes in local control of actin cytoskeletal structures has not been fully elucidated. Circumstantial evidence suggests a function for LPL in either the formation or maintenance of integrin-associated adhesion structures. As LPL may be a target of the commonly used immunosuppressive agent dexamethasone, full elucidation of the regulation and function of LPL in T-cell biology may illuminate new pathways for clinically useful immunotherapeutics.
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Affiliation(s)
- Sharon Celeste Morley
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
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22
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Abstract
It has been over 30 years since the reorganization of both the microtubule network and a 'peculiar actin polarization' was reported at the contact area of cytotoxic T lymphocytes interacting with target cells. Since that time, hundreds of studies have been published in an effort to elucidate the structure and function of the microtubule network and the actin cytoskeleton in T-cell activation, migration, and effector function at the interface between a T cell and its cognate antigen-presenting cell or target cell. This interface has become known as the immunological synapse, and this review examines some of the roles played by the cytoskeleton at the synapse.
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Affiliation(s)
- Alex T Ritter
- Cambridge Institute for Medical Research, University of Cambridge Biomedical CampusCambridge, UK
| | - Karen L Angus
- Cambridge Institute for Medical Research, University of Cambridge Biomedical CampusCambridge, UK
| | - Gillian M Griffiths
- Cambridge Institute for Medical Research, University of Cambridge Biomedical CampusCambridge, UK
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23
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Yu Y, Smoligovets AA, Groves JT. Modulation of T cell signaling by the actin cytoskeleton. J Cell Sci 2013; 126:1049-58. [PMID: 23620508 DOI: 10.1242/jcs.098210] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The actin cytoskeleton provides a dynamic framework to support membrane organization and cellular signaling events. The importance of actin in T cell function has long been recognized to go well beyond the maintenance of cell morphology and transport of proteins. Over the past several years, our understanding of actin in T cell activation has expanded tremendously, in part owing to the development of methods and techniques to probe the complex interplay between actin and T cell signaling. On the one hand, biochemical methods have led to the identification of many key cytoskeleton regulators and new signaling pathways, whereas, on the other, the combination of advanced imaging techniques and physical characterization tools has allowed the spatiotemporal investigation of actin in T cell signaling. All those studies have made a profound impact on our understanding of the actin cytoskeleton in T cell activation. Many previous reviews have focused on the biochemical aspects of the actin cytoskeleton. However, here we will summarize recent studies from a biophysical perspective to explain the mechanistic role of actin in modulating T cell activation. We will discuss how actin modulates T cell activation on multiple time and length scales. Specifically, we will reveal the distinct roles of the actin filaments in facilitating TCR triggering, orchestrating 'signalosome' assembly and transport, and establishing protein spatial organization in the immunological synapse.
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Affiliation(s)
- Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA.
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24
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Haas R, Marelli-Berg F, Mauro C. In the eye of the storm: T cell behavior in the inflammatory microenvironment. AMERICAN JOURNAL OF CLINICAL AND EXPERIMENTAL IMMUNOLOGY 2013; 2:146-155. [PMID: 23885332 PMCID: PMC3714175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 06/07/2013] [Indexed: 06/02/2023]
Abstract
Coordinated unfolding of innate and adaptive immunity is key to the development of protective immune responses. This functional integration occurs within the inflamed tissue, a microenvironment enriched with factors released by innate and subsequently adaptive immune cells and the injured tissue itself. T lymphocytes are key players in the ensuing adaptive immunity and their proper function is instrumental to a successful outcome of immune protection. The site of inflammation is a "harsh" environment in which T cells are exposed to numerous factors that might influence their behavior. Low pH and oxygen concentration, high lactate and organic acid content as well as free fatty acids and reactive oxygen species are found in the inflammatory microenvironment. All these components affect T cells as well as other immune cells during the immune response and impact on the development of chronic inflammation. We here overview the effects of a number of factors present in the inflammatory microenvironment on T cell function and migration and discuss the potential relevance of these components as targets for therapeutic intervention in autoimmune and chronic inflammatory diseases.
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Affiliation(s)
- Robert Haas
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London Charterhouse Square, London EC1M 6BQ, UK
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25
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The Rac activator DOCK2 regulates natural killer cell-mediated cytotoxicity in mice through the lytic synapse formation. Blood 2013; 122:386-93. [PMID: 23719299 DOI: 10.1182/blood-2012-12-475897] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Natural killer (NK) cells play an important role in protective immunity against viral infection and tumor progression, but they also contribute to rejection of bone marrow grafts via contact-dependent cytotoxicity. Ligation of activating NK receptors with their ligands expressed on target cells induces receptor clustering and actin reorganization at the interface and triggers polarized movement of lytic granules to the contact site. Although activation of the small GTPase Rac has been implicated in NK cell-mediated cytotoxicity, its precise role and the upstream regulator remain elusive. Here, we show that DOCK2, an atypical guanine nucleotide exchange factor for Rac, plays a key role in NK cell-mediated cytotoxicity. We found that although DOCK2 deficiency in NK cells did not affect conjugate formation with target cells, DOCK2-deficienct NK cells failed to effectively kill leukemia cells in vitro and major histocompatibility complex class I-deficient bone marrow cells in vivo, regardless of the sorts of activating receptors. In DOCK2-deficient NK cells, NKG2D-mediated Rac activation was almost completely lost, resulting in a severe defect in the lytic synapse formation. Similar results were obtained when the Rac guanine nucleotide exchange factor activity of DOCK2 was selectively abrogated. These results indicate that DOCK2-Rac axis controls NK cell-mediated cytotoxicity through the lytic synapse formation.
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26
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T cell antigen receptor activation and actin cytoskeleton remodeling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:546-56. [PMID: 23680625 DOI: 10.1016/j.bbamem.2013.05.004] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/02/2013] [Indexed: 12/20/2022]
Abstract
T cells constitute a crucial arm of the adaptive immune system and their optimal function is required for a healthy immune response. After the initial step of T cell-receptor (TCR) triggering by antigenic peptide complexes on antigen presenting cell (APC), the T cell exhibits extensive cytoskeletal remodeling. This cytoskeletal remodeling leads to the formation of an "immunological synapse" [1] characterized by regulated clustering, segregation and movement of receptors at the interface. Synapse formation regulates T cell activation and response to antigenic peptides and proceeds via feedback between actin cytoskeleton and TCR signaling. Actin polymerization participates in various events during the synapse formation, maturation, and eventually its disassembly. There is increasing knowledge about the actin effectors that couple TCR activation to actin rearrangements [2,3], and how defects in these effectors translate into impairment of T cell activation. In this review we aim to summarize and integrate parts of what is currently known about this feedback process. In addition, in light of recent advancements in our understanding of TCR triggering and translocation at the synapse, we speculate on the organizational and functional diversity of microfilament architecture in the T cell. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
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Jux B, Staratschek-Jox A, Penninger JM, Schultze JL, Kolanus W. Vav1 regulates MHCII expression in murine resting and activated B cells. Int Immunol 2013; 25:307-17. [PMID: 23391492 DOI: 10.1093/intimm/dxs157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vav1 is a guanine nucleotide exchange factor (GEF) for Rho GTPases, which is exclusively expressed in cells of the hematopoietic system. In addition to its well-documented GEF activity, it was suggested to have other functions due to the presence of multiple domains and nuclear localization signals in its protein structure. Although GEF-dependent and GEF-independent functions of vav have been implicated in T-cell development and T-cell receptor signaling, the role of vav1 in antigen-presenting cells is poorly understood. We found that vav1 is an important regulator of MHCII expression and transport. Microarray analysis of unstimulated bone marrow-derived macrophages revealed a novel role of vav1 in transcriptional regulation of the MHCII locus, possibly by indirect means. Primary immune cells from vav1-deficient mice had a significantly lower constitutive surface expression of MHCII with the strongest impact observed on splenic and peritoneal B cells. Impaired MHCII expression resulted in a diminished capacity for T-cell activation. Using 6-thio-GTP, a specific inhibitor of the GEF function of vav1, we were able to show that the GEF activity is required for MHCII upregulation in B cells after stimulation with LPS. Furthermore, our data show that vav1 not only affects transcription of the MHCII locus but also is an important regulator of MHCII protein transport to the cell surface.
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Affiliation(s)
- Bettina Jux
- Department of Molecular Immune and Cell Biology, Life and Medical Sciences (LIMES) Institute, University of Bonn, Germany.
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28
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Curado S, Kumari S, Dustin ML. "Cell biology meets physiology: functional organization of vertebrate plasma membranes"--the immunological synapse. CURRENT TOPICS IN MEMBRANES 2013; 72:313-46. [PMID: 24210434 PMCID: PMC4878826 DOI: 10.1016/b978-0-12-417027-8.00009-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The immunological synapse (IS) is an excellent example of cell-cell communication, where signals are exchanged between two cells, resulting in a well-structured line of defense during adaptive immune response. This process has been the focus of several studies that aimed at understanding its formation and subsequent events and has led to the realization that it relies on a well-orchestrated molecular program that only occurs when specific requirements are met. The development of more precise and controllable T cell activation systems has led to new insights including the role of mechanotransduction in the process of formation of the IS and T cell activation. Continuous advances in our understanding of the IS formation, particularly in the context of T cell activation and differentiation, as well the development of new T cell activation systems are being applied to the establishment and improvement of immune therapeutical approaches.
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Affiliation(s)
- Silvia Curado
- Skirball Institute of Biomolecular Medicine, and Department of Pathology, New York University School of Medicine, 540 First Ave, New York, NY 10016, USA and Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Roosevelt Drive, Headington, Oxfordshire, OX3 7FY, UK
| | - Sudha Kumari
- Skirball Institute of Biomolecular Medicine, and Department of Pathology, New York University School of Medicine, 540 First Ave, New York, NY 10016, USA and Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Roosevelt Drive, Headington, Oxfordshire, OX3 7FY, UK
| | - Michael L. Dustin
- Skirball Institute of Biomolecular Medicine, and Department of Pathology, New York University School of Medicine, 540 First Ave, New York, NY 10016, USA and Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Roosevelt Drive, Headington, Oxfordshire, OX3 7FY, UK
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Li SY, Du MJ, Wan YJ, Lan B, Liu YH, Yang Y, Zhang CZ, Cao Y. The N-terminal 20-amino acid region of guanine nucleotide exchange factor Vav1 plays a distinguished role in T cell receptor-mediated calcium signaling. J Biol Chem 2012; 288:3777-85. [PMID: 23271736 DOI: 10.1074/jbc.m112.426221] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Vav1 is a guanine nucleotide exchange factor (GEF) specifically expressed in hematopoietic cells. It consists of multiple structural domains and plays important roles in T cell activation. The other highly conserved isoforms of Vav family, Vav2 and Vav3, are ubiquitously expressed in human tissues including lymphocytes. All three Vav proteins activate Rho family small GTPases, which are involved in a variety of biological processes during T cell activation. Intensive studies have demonstrated that Vav1 is indispensable for T cell receptor (TCR)-mediated signal transduction, whereas Vav2 and Vav3 function as GEFs that overlap with Vav1 on TCR-induced cytoskeleton reorganization. T cells lacking Vav1 exhibited severe defect in TCR-mediated calcium elevation, indicating that the co-existing Vav2 and Vav3 did not compensate Vav1 in calcium signaling. What is the functional particularity of Vav1 in lymphocytes? In this study, we identified the N-terminal 20 amino acids of Vav1 in the calponin homology (CH) domain to be essential for its interaction with calmodulin (CaM) that leads to TCR-induced calcium mobilization. Substitution of the 1-20 amino acids of Vav1 with those of Vav2 or Vav3 abolished the association with CaM, and the N-terminal mutations of Vav1 failed to potentiate normal TCR-induced calcium mobilization, that in turn, suspended nuclear factor of activated T cells (NFAT) activation and IL-2 production. This study highlights the importance of the N-terminal 20 aa of Vav1 for CaM binding, and provides new insights into the distinguished and irreplaceable role of Vav1 in T cell activation and signal transduction.
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Affiliation(s)
- Shi-Yang Li
- Key Laboratory of Microbial Functional Genomics of the Ministry of Education, Medicinal Chemical Biology College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, Peoples Republic of China
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30
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Ksionda O, Saveliev A, Köchl R, Rapley J, Faroudi M, Smith-Garvin JE, Wülfing C, Rittinger K, Carter T, Tybulewicz VLJ. Mechanism and function of Vav1 localisation in TCR signalling. J Cell Sci 2012; 125:5302-14. [PMID: 22956543 PMCID: PMC3561853 DOI: 10.1242/jcs.105148] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The antigen-specific binding of T cells to antigen presenting cells results in recruitment of signalling proteins to microclusters at the cell-cell interface known as the immunological synapse (IS). The Vav1 guanine nucleotide exchange factor plays a critical role in T cell antigen receptor (TCR) signalling, leading to the activation of multiple pathways. We now show that it is recruited to microclusters and to the IS in primary CD4+ and CD8+ T cells. Furthermore, we show that this recruitment depends on the SH2 and C-terminal SH3 (SH3B) domains of Vav1, and on phosphotyrosines 112 and 128 of the SLP76 adaptor protein. Biophysical measurements show that Vav1 binds directly to these residues on SLP76 and that efficient binding depends on the SH2 and SH3B domains of Vav1. Finally, we show that the same two domains are critical for the phosphorylation of Vav1 and its signalling function in TCR-induced calcium flux. We propose that Vav1 is recruited to the IS by binding to SLP76 and that this interaction is critical for the transduction of signals leading to calcium flux.
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Affiliation(s)
- Olga Ksionda
- Division of Immune Cell Biology, MRC National Institute for Medical Research, London NW7 1AA, UK
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31
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Li X, Utomo A, Cullere X, Choi MM, Milner DA, Venkatesh D, Yun SH, Mayadas TN. The β-glucan receptor Dectin-1 activates the integrin Mac-1 in neutrophils via Vav protein signaling to promote Candida albicans clearance. Cell Host Microbe 2012; 10:603-15. [PMID: 22177564 DOI: 10.1016/j.chom.2011.10.009] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 06/29/2011] [Accepted: 10/04/2011] [Indexed: 11/25/2022]
Abstract
Resistance to fungal infections is attributed to engagement of host pattern-recognition receptors, notably the β-glucan receptor Dectin-1 and the integrin Mac-1, which induce phagocytosis and antifungal immunity. However, the mechanisms by which these receptors coordinate fungal clearance are unknown. We show that upon ligand binding, Dectin-1 activates Mac-1 to also recognize fungal components, and this stepwise process is critical for neutrophil cytotoxic responses. Both Mac-1 activation and Dectin-1- and Mac-1-induced neutrophil effector functions require Vav1 and Vav3, exchange factors for RhoGTPases. Mac-1- or Vav1,3-deficient mice have increased susceptibility to systemic candidiasis that is not due to impaired neutrophil recruitment but defective intracellular killing of C. albicans yeast forms, and Mac-1 or Vav1,3 reconstitution in hematopoietic cells restores resistance. Our results demonstrate that antifungal immunity depends on Dectin-1-induced activation of Mac-1 functions that is coordinated by Vav proteins, a pathway that may localize cytotoxic responses of circulating neutrophils to infected tissues.
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Affiliation(s)
- Xun Li
- Center for Excellence in Vascular Biology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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32
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Knyazhitsky M, Moas E, Shaginov E, Luria A, Braiman A. Vav1 oncogenic mutation inhibits T cell receptor-induced calcium mobilization through inhibition of phospholipase Cγ1 activation. J Biol Chem 2012; 287:19725-35. [PMID: 22474331 DOI: 10.1074/jbc.m111.309799] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Robust elevation of the cytosolic calcium concentration is a crucial early step for T cell activation triggered by the T cell antigen receptor. Vav1 is a proto-oncogene expressed in hematopoietic cells that is indispensable for transducing the calcium-mobilizing signal. Following T cell receptor stimulation, Vav1 facilitates formation of signaling microclusters through multiple interactions with other proteins participating in the signaling cascade. Truncation of the N terminus of Vav1 produces its oncogenic version, which is unable to support normal calcium flux following T cell activation. We show here that truncation of the N-terminal region of Vav1 alters the fine structure of protein complexes in the signaling clusters, affecting the interaction of Vav1 with phospholipase Cγ1 (PLCγ1). This alteration is accompanied by a decrease in PLCγ1 phosphorylation and inhibition of inositol 1,4,5-trisphosphate production. We suggest that the structural integrity of the N-terminal region of Vav1 is important for the proper formation of the Vav1-associated signaling complexes. The oncogenic truncation of this region elicits conformational changes that interfere with the Vav1-mediated activation of PLCγ1 and that inhibit calcium mobilization.
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Affiliation(s)
- Mira Knyazhitsky
- Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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33
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Interplay of polarity proteins and GTPases in T-lymphocyte function. Clin Dev Immunol 2012; 2012:417485. [PMID: 22461835 PMCID: PMC3296228 DOI: 10.1155/2012/417485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/13/2011] [Indexed: 01/16/2023]
Abstract
Polarity refers to the asymmetric distribution of different cellular components within a cell and is central to many cell functions. In T-cells, polarity regulates the activation, migration, and effector function of cytotoxic T-cells (CTLs) during an immune response. The regulation of asymmetric cell division by polarity proteins may also dictate CTL effector and memory differentiation following antigen presentation. Small GTPases, along with their associated polarity and adaptor proteins, are critical for mediating the polarity changes necessary for T-cell activation and function, and in turn, are regulated by guanine exchange factors (GEFS) and GTPase activating proteins (GAPS). For example, a novel GEF, dedicator of cytokinesis 8 (DOCK8) was recently identified as a regulator of immune cell function and mutations in DOCK8 have been detected in patients with severe combined immunodeficiency. Both B and T-cells from DOCK8 mutant mice form defective immunological synapses and have abnormal functions, in addition to impaired immune memory development. This paper will discuss the interplay between polarity proteins and GTPases, and their role in T-cell function.
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34
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Lasserre R, Cuche C, Blecher-Gonen R, Libman E, Biquand E, Danckaert A, Yablonski D, Alcover A, Di Bartolo V. Release of serine/threonine-phosphorylated adaptors from signaling microclusters down-regulates T cell activation. ACTA ACUST UNITED AC 2011; 195:839-53. [PMID: 22105350 PMCID: PMC3257567 DOI: 10.1083/jcb.201103105] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Serine/threonine phosphorylation of the T cell adaptor proteins SLP76 and GADS by HPK1 induces their release from signaling microclusters and subsequent termination of the T cell response. Antigen recognition within immunological synapses triggers and sustains T cell activation by nucleating protein microclusters that gather T cell receptors (TCRs), kinases, and adaptors. Dissipation of these microclusters results in signal termination, but how this process is regulated is unclear. In this paper, we reveal that release of the adaptors SLP76 and GADS from signaling microclusters is induced by the serine/threonine protein kinase HPK1 and that phosphorylation of GADS plays a major role in this process. We found that HPK1 was recruited into microclusters and triggered their dissipation by inducing the phosphorylation of a threonine-containing motif of GADS, together with the previously described serine phosphorylation of SLP76. These events induced the cooperative binding of 14-3-3 proteins to SLP76–GADS complexes, leading to their uncoupling from the transmembrane adaptor LAT and consequently reducing microcluster persistence and activation-induced gene transcription. These results demonstrate that serine/threonine phosphorylation of multiple TCR-proximal effectors controls the stability of signaling microclusters, thereby determining the intensity of T cell responses.
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Affiliation(s)
- Rémi Lasserre
- Lymphocyte Cell Biology Unit, Department of Immunology, Imagopole, Institut Pasteur, F-75015 Paris, Cedex 15, France
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35
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Impairment of non-muscle myosin IIA in human CD4+ T cells contributes to functional deficits in the elderly. Cell Mol Immunol 2011; 9:86-96. [PMID: 21983869 DOI: 10.1038/cmi.2011.41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Physiological aging imposes significant alterations in the repertoire of T cells and all associated functions. Although several studies have reported defects upon antigen-induced activation of T cells during aging, the molecular mechanisms that control T-cell receptor (TCR) downmodulation remain to be fully defined. While previous studies have assessed the role of F-actin in regulating activation-induced TCR internalization, few have delineated the roles of motor proteins, such as non-muscle myosin IIA (NMMIIA). In this study, we describe a series of experiments supporting the hypothesis that effective TCR downmodulation requires not only efficient reorganization of the actin cytoskeleton, but also functional NMMIIA. For the first time, we show that CD4(+) T cells from elderly human donors have dysfunctional NMMIIA that contributes to delaying activation-induced TCR internalization and impairing calcium mobilization. Additionally, our results demonstrate that chemical inhibition of NMMIIA in CD4(+) T cells from young donors also results in complete abrogation of TCR internalization, strongly supporting the fundamental role of NMMIIA in modulating this event. Recent observations that the generation of an efficient T-cell response requires migration prompted us to investigate whether NMMIIA also plays a regulatory role in CD4(+) T-cell migration. We show that chemical inhibition of NMMIIA downmodulates chemotactic migration in CD4(+) T cells from both young and elderly donors. Together, these data demonstrate a significant contribution of dysfunctional NMMIIA to TCR-mediated functional defects during aging.
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36
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Colacios C, Casemayou A, Dejean AS, Gaits-Iacovoni F, Pedros C, Bernard I, Lagrange D, Deckert M, Lamouroux L, Jagodic M, Olsson T, Liblau RS, Fournié GJ, Saoudi A. The p.Arg63Trp polymorphism controls Vav1 functions and Foxp3 regulatory T cell development. ACTA ACUST UNITED AC 2011; 208:2183-91. [PMID: 21948080 PMCID: PMC3201202 DOI: 10.1084/jem.20102191] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A single nucleotide polymorphism causing constitutive activation of Vav1 results in increased natural Treg generation and is responsible for the imbalance between Vav1 GEF and adaptor functions. CD4+ regulatory T cells (Treg cells) expressing the transcription factor Foxp3 play a pivotal role in maintaining peripheral tolerance by inhibiting the expansion and function of pathogenic conventional T cells (Tconv cells). In this study, we show that a locus on rat chromosome 9 controls the size of the natural Treg cell compartment. Fine mapping of this locus with interval-specific congenic lines and association experiments using single nucleotide polymorphisms (SNPs) identified a nonsynonymous SNP in the Vav1 gene that leads to the substitution of an arginine by a tryptophan (p.Arg63Trp). This p.Arg63Trp polymorphism is associated with increased proportion and absolute numbers of Treg cells in the thymus and peripheral lymphoid organs, without impacting the size of the Tconv cell compartment. This polymorphism is also responsible for Vav1 constitutive activation, revealed by its tyrosine 174 hyperphosphorylation and increased guanine nucleotide exchange factor activity. Moreover, it induces a marked reduction in Vav1 cellular contents and a reduction of Ca2+ flux after TCR engagement. Together, our data reveal a key role for Vav1-dependent T cell antigen receptor signaling in natural Treg cell development.
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Affiliation(s)
- Céline Colacios
- INSERM Unité 1043, Centre National de la Recherche Scientifique Unité 5282, Toulouse, France
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Jansen van Vuren P, Tiemessen CT, Paweska JT. Anti-nucleocapsid protein immune responses counteract pathogenic effects of Rift Valley fever virus infection in mice. PLoS One 2011; 6:e25027. [PMID: 21949840 PMCID: PMC3174991 DOI: 10.1371/journal.pone.0025027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 08/25/2011] [Indexed: 12/31/2022] Open
Abstract
The known virulence factor of Rift Valley fever virus (RVFV), the NSs protein, counteracts the antiviral effects of the type I interferon response. In this study we evaluated the expression of several genes in the liver and spleen involved in innate and adaptive immunity of mice immunized with a RVFV recombinant nucleocapsid protein (recNP) combined with Alhydrogel adjuvant and control animals after challenge with wild type RVFV. Mice immunized with recNP elicited an earlier IFNβ response after challenge compared to non-immunized controls. In the acute phase of liver infection in non-immunized mice there was a massive upregulation of type I and II interferon, accompanied by high viral titers, and the up- and downregulation of several genes involved in the activation of B- and T-cells, indicating that both humoral and cellular immunity is modulated during RVFV infection. Various genes involved in pro-inflammatory responses and with pro-apoptotic effects were strongly upregulated and anti-apoptotic genes were downregulated in liver of non-immunized mice. Expression of many genes involved in B- and T-cell immunity were downregulated in spleen of non-immunized mice but normal in immunized mice. A strong bias towards apoptosis and inflammation in non-immunized mice at an acute stage of liver infection associated with suppression of several genes involved in activation of humoral and cellular immunity in spleen, suggests that RVFV evades the host immune response in more ways than only by inhibition of type I interferon, and that immunopathology of the liver plays a crucial role in RVF disease progression.
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Affiliation(s)
- Petrus Jansen van Vuren
- Special Pathogens Unit, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, South Africa
- Division Virology and Communicable Diseases Surveillance, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Caroline T. Tiemessen
- Division Virology and Communicable Diseases Surveillance, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
- Cell Biology/AIDS Virus Research Unit, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, South Africa
| | - Janusz T. Paweska
- Special Pathogens Unit, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, South Africa
- Division Virology and Communicable Diseases Surveillance, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
- * E-mail:
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Bertagnolo V, Grassilli S, Petretto A, Lambertini E, Astati L, Bruschi M, Brugnoli F, Nika E, Candiano G, Piva R, Capitani S. Nuclear proteome analysis reveals a role of Vav1 in modulating RNA processing during maturation of tumoral promyelocytes. J Proteomics 2011; 75:398-409. [PMID: 21856460 DOI: 10.1016/j.jprot.2011.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 07/28/2011] [Accepted: 08/06/2011] [Indexed: 01/02/2023]
Abstract
Vav1 is a key molecule in the ATRA-induced acquisition of a mature phenotype by tumoral myeloid precursors. Since ATRA acts throughout events that require extensive changes of nuclear architecture and activity and considering that Vav1 accumulates inside the nuclear compartment of differentiating APL-derived cells, the possible role of this protein in modulating the nuclear proteome was investigated. Membrane-depleted nuclei purified from NB4 cells induced to differentiate with ATRA in the presence of forcedly down-modulated Vav1 were subjected to 2D-DIGE followed by mass spectra analysis. The obtained data demonstrated that, in NB4 cells treated with ATRA, Vav1 is involved in determining the nuclear amount of proteins involved in molecular complexes with DNA and may participate to RNA processing by carrying in the nucleus molecules involved in modulating mRNA production and stability, like hnRNPs and SR proteins. Our results provide the first evidence that, at least in maturation of tumoral myeloid precursors, Vav1 is part of interconnected networks of functionally related proteins ended to regulate different aspects of gene expression. Since defects in mRNA processing are common in tumor development, our data suggest that Vav1 is a potential target molecule for developing new anti-cancer strategies.
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Affiliation(s)
- Valeria Bertagnolo
- Signal Transduction Unit, Section of Human Anatomy, Department of Morphology and Embryology, University of Ferrara, Italy.
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Vav1 is a crucial molecule in monocytic/macrophagic differentiation of myeloid leukemia-derived cells. Cell Tissue Res 2011; 345:163-75. [PMID: 21647562 DOI: 10.1007/s00441-011-1195-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 05/13/2011] [Indexed: 12/25/2022]
Abstract
Vav1 is a critical signal transducer for both the development and function of normal hematopoietic cells, in which it regulates the acquisition of maturation-related properties, including adhesion, motility, and phagocytosis. Vav1 is also important for the agonist-induced maturation of acute promyelocytic leukemia (APL)-derived promyelocytes, in which it promotes the acquisition of a mature phenotype by playing multiple functions at both cytoplasmic and nuclear levels. We investigated the possible role of Vav1 in the differentiation of leukemic precursors to monocytes/macrophages. Tumoral promyelocytes in which Vav1 was negatively modulated were induced to differentiate into monocytes/macrophages with phorbol-12-myristate-13-acetate (PMA) and monitored for their maturation-related properties. We found that Vav1 was crucial for the phenotypical differentiation of tumoral myeloid precursors to monocytes/macrophages, in terms of CD11b expression, adhesion capability and cell morphology. Confocal analysis revealed that Vav1 may synergize with actin in modulating nuclear morphology of PMA-treated adherent cells. Our data indicate that, in tumoral promyelocytes, Vav1 is a component of lineage-specific transduction machineries that can be recruited by various differentiating agents. Since Vav1 plays a central role in the completion of the differentiation program of leukemic promyelocytes along diverse hematopoietic lineages, it can be considered a common target for developing new therapeutic strategies for the various subtypes of myeloid leukemias.
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40
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Sylvain NR, Nguyen K, Bunnell SC. Vav1-mediated scaffolding interactions stabilize SLP-76 microclusters and contribute to antigen-dependent T cell responses. Sci Signal 2011; 4:ra14. [PMID: 21386095 DOI: 10.1126/scisignal.2001178] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The guanine nucleotide exchange factor (GEF) Vav1 synergizes with the adaptor protein SLP-76 (Src homology 2 domain--containing leukocyte phosphoprotein of 76 kD) to support T cell development and activation. In response to ligation of the T cell receptor (TCR), SLP-76 is assembled into microclusters that provide an essential platform for the signaling events that drive T cell activation. We found that Vav1 selectively entered SLP-76 microclusters, rather than TCR microclusters, influencing their stability and function. The carboxyl terminus of Vav1, which consists of Src homology domains, was both necessary and sufficient for the entry of Vav1 into SLP-76 microclusters; however, this fragment of Vav1 was insufficient to stabilize the microclusters, and it potently suppressed T cell activation. This indicated that the amino terminus of Vav1, which has the GEF domain, also contributed to the integrity of SLP-76 microclusters and thereby to T cell activation. These microcluster-stabilizing functions were independent of the GEF activity in the amino terminus of Vav1 and were unaffected if the GEF function of Vav1 was either inactivated or constitutively activated by mutation. In contrast, Vav1 deletion mutants lacking either the calponin homology domain or the catalytic core of the GEF exhibited mild scaffolding defects, but they differentially affected TCR-dependent calcium ion (Ca²+) responses. We conclude that multiple GEF-independent scaffolding functions distributed throughout the amino terminus of Vav1 contribute to the activation of T cells by acting synergistically to increase the stability and function of SLP-76 microclusters.
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Affiliation(s)
- Nicholas R Sylvain
- Program in Immunology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
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41
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Yin J, Wan YJ, Li SY, Du MJ, Zhang CZ, Zhou XL, Cao YJ. The distinct role of guanine nucleotide exchange factor Vav1 in Bcl-2 transcription and apoptosis inhibition in Jurkat leukemia T cells. Acta Pharmacol Sin 2011; 32:99-107. [PMID: 21151158 PMCID: PMC4003318 DOI: 10.1038/aps.2010.185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 09/28/2010] [Indexed: 11/09/2022] Open
Abstract
AIM To investigate a novel function of proto-oncogene Vav1 in the apoptosis of human leukemia Jurkat cells. METHODS Jurkat cells, Jurkat-derived vav1-null cells (J.Vav1) and Vav1-reconstituted J.WT cells were treated with a Fas agonist antibody, IgM clone CH11. Apoptosis was determined using propidium iodide (PI) staining, Annexin-V staining, DNA fragmentation, cleavage of caspase 3/caspase 8, and poly (ADP-ribose) polymerase (PARP). Mitochondria transmembrane potential (ΔΨ(m)) was measured using DiOC(6)(3) staining. Transcription and expression of the Bcl-2 family of proteins were evaluated using semi-quantitative RT-PCR and Western blot, respectively. Bcl-2 promoter activity was analyzed using luciferase reporter assays. RESULTS Cells lacking Vav1 were more sensitive to Fas-mediated apoptosis than Jurkat and J.WT cells. J.Vav1 cells lost mitochondria transmembrane potential (ΔΨ(m)) more rapidly upon Fas induction. These phenotypes could be rescued by re-expression of Vav1 in J.Vav1 cells. The expression of Vav1 increased the transcription of pro-survival Bcl-2. The guanine nucleotide exchange activity of Vav1 was required for enhancing Bcl-2 promoter activity, and the Vav1 downstream substrate, small GTPase Rac2, was likely involved in the control of Bcl-2 expression. CONCLUSION Vav1 protects Jurkat cells from Fas-mediated apoptosis by promoting Bcl-2 transcription through its GEF activity.
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Affiliation(s)
- Jie Yin
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ya-juan Wan
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Shi-yang Li
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ming-juan Du
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Cui-zhu Zhang
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xing-long Zhou
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - You-jia Cao
- Tianjin Key Laboratory of Protein Sciences, Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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Park H, Chan MM, Iritani BM. Hem-1: putting the "WAVE" into actin polymerization during an immune response. FEBS Lett 2010; 584:4923-32. [PMID: 20969869 DOI: 10.1016/j.febslet.2010.10.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 09/28/2010] [Accepted: 10/13/2010] [Indexed: 11/28/2022]
Abstract
Most active processes by immune cells including adhesion, migration, and phagocytosis require the coordinated polymerization and depolymerization of filamentous actin (F-actin), which is an essential component of the actin cytoskeleton. This review focuses on a newly characterized hematopoietic cell-specific actin regulatory protein called hematopoietic protein-1 [Hem-1, also known as Nck-associated protein 1-like (Nckap1l or Nap1l)]. Hem-1 is a component of the "WAVE [WASP (Wiskott-Aldrich syndrome protein)-family verprolin homologous protein]" complex, which signals downstream of activated Rac to stimulate F-actin polymerization in response to immuno-receptor signaling. Genetic studies in cell lines and in mice suggest that Hem-1 regulates F-actin polymerization in hematopoietic cells, and may be essential for most active processes dependent on reorganization of the actin cytoskeleton in immune cells.
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Affiliation(s)
- Heon Park
- Department of Comparative Medicine, University of Washington, Seattle, WA 98195-7190, USA.
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Beemiller P, Krummel MF. Mediation of T-cell activation by actin meshworks. Cold Spring Harb Perspect Biol 2010; 2:a002444. [PMID: 20702599 DOI: 10.1101/cshperspect.a002444] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Although the actin cytoskeleton and T-cell receptor (TCR) signaling complexes are seemingly distinct molecular structures, they are tightly integrated in T cells. The signaling pathways initiated by TCRs binding to peptide MHC complexes are extensively influenced by the actin cytoskeletal activities of the motile phase before TCR signaling, the signalosome scaffolding function of the cytoskeleton, and the translocation of signaling clusters that precedes the termination of signaling at these complexes. As these three successive phases constitute essentially all the steps consequent to immune synapse formation, it has become clear that the substantial physical forces and signaling interactions generated by the actin cytoskeleton dominate the signaling life cycle of TCR signalosomes. We discuss the contributions of the actin cytoskeleton to TCR signaling phases and model some remaining questions about how specific cytoskeletal factors regulate TCR signaling outcomes.
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Affiliation(s)
- Peter Beemiller
- Department of Pathology, University of California, San Francisco, San Francisco, California 94143-0511, USA
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Vav1 couples the T cell receptor to cAMP response element activation via a PKC-dependent pathway. Cell Signal 2010; 22:944-54. [PMID: 20138987 DOI: 10.1016/j.cellsig.2010.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/25/2010] [Accepted: 02/01/2010] [Indexed: 12/21/2022]
Abstract
The transcription factor cAMP-responsive element binding protein (CREB) is a regulator of the expression of several genes important for lymphocyte activation and proliferation. However, the proximal signaling events leading to activation of CREB in T cells upon antigen receptor stimulation remain unknown. Here we identify a role for Vav1 in the activation of the cAMP response element (CRE), the binding site for CREB. T cell receptor (TCR)/CD28 - induced costimulation of Jurkat T cells expressing Vav1 but not a GEF-deficient mutant showed increased CRE activation (7.2+/-2.4 fold over control), whereas Vav1 downregulation by siRNA reduced activation of CRE by 2.6+/-1.3 fold. Inhibition of PKC and MEK but not p38 could reduce Vav1-mediated CRE activation, suggesting that Vav1 transmits TCR and CD28 signals to activation of CRE via PKC and ERK signaling pathways. As a consequence, downregulation of Vav1 impaired the expression of several CRE-containing genes like cyclin D1, INFgamma and IL-2, whereas overexpression of Vav1 enhanced CRE-dependent gene expression. Furthermore, cAMP-induced CRE-dependent transcription and gene expression was also modulated by Vav1, but did not require activation of PKC and the GEF function of Vav1. Our data provide insights into the signal transduction events regulating CRE-mediated gene expression in T cells, which affects T cell development, proliferation and activation. We identify Vav1 as an essential component of TCR-induced CRE activation and gene expression, which underlines the central role for Vav1 as key player for TCR signal transduction and gene expression.
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Saveliev A, Vanes L, Ksionda O, Rapley J, Smerdon SJ, Rittinger K, Tybulewicz VLJ. Function of the nucleotide exchange activity of vav1 in T cell development and activation. Sci Signal 2009; 2:ra83. [PMID: 20009105 PMCID: PMC3434450 DOI: 10.1126/scisignal.2000420] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The guanine nucleotide exchange factor (GEF) Vav1 is essential for transducing T cell antigen receptor (TCR) signals and therefore plays a critical role in the development and activation of T cells. It has been presumed that the GEF activity of Vav1 is important for its function; however, there has been no direct demonstration of this. Here, we generated mice expressing enzymatically inactive, but normally folded, Vav1 protein. Analysis of these mice showed that the GEF activity of Vav1 was necessary for the selection of thymocytes and for the optimal activation of T cells, including signal transduction to Rac1, Akt, and integrins. In contrast, the GEF activity of Vav1 was not required for TCR-induced calcium flux, activation of extracellular signal-regulated kinase and protein kinase D1, and cell polarization. Thus, in T cells, the GEF activity of Vav1 is essential for some, but not all, of its functions.
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Affiliation(s)
- Alexander Saveliev
- Division of Immune Cell Biology, MRC National Institute for Medical Research, London, UK
| | - Lesley Vanes
- Division of Immune Cell Biology, MRC National Institute for Medical Research, London, UK
| | - Olga Ksionda
- Division of Immune Cell Biology, MRC National Institute for Medical Research, London, UK
| | - Jonathan Rapley
- Division of Immune Cell Biology, MRC National Institute for Medical Research, London, UK
- Division of Molecular Structure, MRC National Institute for Medical Research, London, UK
| | - Stephen J. Smerdon
- Division of Molecular Structure, MRC National Institute for Medical Research, London, UK
| | - Katrin Rittinger
- Division of Molecular Structure, MRC National Institute for Medical Research, London, UK
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