1
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Lee HN, Lee SE, Inn KS, Seong J. Optical sensing and control of T cell signaling pathways. Front Physiol 2024; 14:1321996. [PMID: 38269062 PMCID: PMC10806162 DOI: 10.3389/fphys.2023.1321996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024] Open
Abstract
T cells regulate adaptive immune responses through complex signaling pathways mediated by T cell receptor (TCR). The functional domains of the TCR are combined with specific antibodies for the development of chimeric antigen receptor (CAR) T cell therapy. In this review, we first overview current understanding on the T cell signaling pathways as well as traditional methods that have been widely used for the T cell study. These methods, however, are still limited to investigating dynamic molecular events with spatiotemporal resolutions. Therefore, genetically encoded biosensors and optogenetic tools have been developed to study dynamic T cell signaling pathways in live cells. We review these cutting-edge technologies that revealed dynamic and complex molecular mechanisms at each stage of T cell signaling pathways. They have been primarily applied to the study of dynamic molecular events in TCR signaling, and they will further aid in understanding the mechanisms of CAR activation and function. Therefore, genetically encoded biosensors and optogenetic tools offer powerful tools for enhancing our understanding of signaling mechanisms in T cells and CAR-T cells.
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Affiliation(s)
- Hae Nim Lee
- Brain Science Institute, Korea Institute of Science and Technoloy, Seoul, Republic of Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
| | - Seung Eun Lee
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyung-Soo Inn
- Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
| | - Jihye Seong
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Wide River Institute of Immunology, Seoul National University, Hongcheon, Republic of Korea
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2
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Fernández-Aguilar LM, Vico-Barranco I, Arbulo-Echevarria MM, Aguado E. A Story of Kinases and Adaptors: The Role of Lck, ZAP-70 and LAT in Switch Panel Governing T-Cell Development and Activation. BIOLOGY 2023; 12:1163. [PMID: 37759563 PMCID: PMC10525366 DOI: 10.3390/biology12091163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 09/29/2023]
Abstract
Specific antigen recognition is one of the immune system's features that allows it to mount intense yet controlled responses to an infinity of potential threats. T cells play a relevant role in the host defense and the clearance of pathogens by means of the specific recognition of peptide antigens presented by antigen-presenting cells (APCs), and, to do so, they are equipped with a clonally distributed antigen receptor called the T-cell receptor (TCR). Upon the specific engagement of the TCR, multiple intracellular signals are triggered, which lead to the activation, proliferation and differentiation of T lymphocytes into effector cells. In addition, this signaling cascade also operates during T-cell development, allowing for the generation of cells that can be helpful in the defense against threats, as well as preventing the generation of autoreactive cells. Early TCR signals include phosphorylation events in which the tyrosine kinases Lck and ZAP70 are involved. The sequential activation of these kinases leads to the phosphorylation of the transmembrane adaptor LAT, which constitutes a signaling hub for the generation of a signalosome, finally resulting in T-cell activation. These early signals play a relevant role in triggering the development, activation, proliferation and apoptosis of T cells, and the negative regulation of these signals is key to avoid aberrant processes that could generate inappropriate cellular responses and disease. In this review, we will examine and discuss the roles of the tyrosine kinases Lck and ZAP70 and the membrane adaptor LAT in these cellular processes.
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Grants
- PY20_01297 Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, Spain
- PID2020-113943RB-I00 Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación, Spain
- PR2022-037 University of Cádiz
- PAIDI2020/DOC_01433 Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, Spain
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Affiliation(s)
- Luis M. Fernández-Aguilar
- Institute for Biomedical Research of Cadiz (INIBICA), 11009 Cadiz, Spain; (L.M.F.-A.); (I.V.-B.); (M.M.A.-E.)
- Department of Biomedicine, Biotechnology and Public Health (Immunology), University of Cadiz, 11002 Cadiz, Spain
| | - Inmaculada Vico-Barranco
- Institute for Biomedical Research of Cadiz (INIBICA), 11009 Cadiz, Spain; (L.M.F.-A.); (I.V.-B.); (M.M.A.-E.)
- Department of Biomedicine, Biotechnology and Public Health (Immunology), University of Cadiz, 11002 Cadiz, Spain
| | - Mikel M. Arbulo-Echevarria
- Institute for Biomedical Research of Cadiz (INIBICA), 11009 Cadiz, Spain; (L.M.F.-A.); (I.V.-B.); (M.M.A.-E.)
- Department of Biomedicine, Biotechnology and Public Health (Immunology), University of Cadiz, 11002 Cadiz, Spain
| | - Enrique Aguado
- Institute for Biomedical Research of Cadiz (INIBICA), 11009 Cadiz, Spain; (L.M.F.-A.); (I.V.-B.); (M.M.A.-E.)
- Department of Biomedicine, Biotechnology and Public Health (Immunology), University of Cadiz, 11002 Cadiz, Spain
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3
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Zhao X, Wu LZ, Ng EKY, Leow KWS, Wei Q, Gascoigne NRJ, Brzostek J. Non-Stimulatory pMHC Enhance CD8 T Cell Effector Functions by Recruiting Coreceptor-Bound Lck. Front Immunol 2021; 12:721722. [PMID: 34707605 PMCID: PMC8542885 DOI: 10.3389/fimmu.2021.721722] [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: 06/07/2021] [Accepted: 09/20/2021] [Indexed: 11/17/2022] Open
Abstract
Under physiological conditions, CD8+ T cells need to recognize low numbers of antigenic pMHC class I complexes in the presence of a surplus of non-stimulatory, self pMHC class I on the surface of the APC. Non-stimulatory pMHC have been shown to enhance CD8+ T cell responses to low amounts of antigenic pMHC, in a phenomenon called co-agonism, but the physiological significance and molecular mechanism of this phenomenon are still poorly understood. Our data show that co-agonist pMHC class I complexes recruit CD8-bound Lck to the immune synapse to modulate CD8+ T cell signaling pathways, resulting in enhanced CD8+ T cell effector functions and proliferation, both in vitro and in vivo. Moreover, co-agonism can boost T cell proliferation through an extrinsic mechanism, with co-agonism primed CD8+ T cells enhancing Akt pathway activation and proliferation in neighboring CD8+ T cells primed with low amounts of antigen.
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Affiliation(s)
- Xiang Zhao
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Liang-Zhe Wu
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Esther K Y Ng
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kerisa W S Leow
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Qianru Wei
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Nicholas R J Gascoigne
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Joanna Brzostek
- Immunology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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4
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Leitner J, Mahasongkram K, Schatzlmaier P, Pfisterer K, Leksa V, Pata S, Kasinrerk W, Stockinger H, Steinberger P. Differentiation and activation of human CD4 T cells is associated with a gradual loss of myelin and lymphocyte protein. Eur J Immunol 2021; 51:848-863. [PMID: 33345332 PMCID: PMC8248321 DOI: 10.1002/eji.202048603] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 10/21/2020] [Accepted: 12/17/2020] [Indexed: 02/04/2023]
Abstract
Upon generation of monoclonal antibodies to the T cell antigen receptor/CD3 (TCR/CD3) complex, we isolated mAb MT3, whose reactivity correlates inversely with the production of IFN‐γ by human peripheral blood T lymphocytes. Using eukaryotic expression cloning, we identified the MT3 antigen as myelin‐and‐lymphocyte (MAL) protein. Flow cytometry analysis demonstrates high surface expression of MAL on all naïve CD4+ T cells whereas MAL expression is diminished on central memory‐ and almost lost on effector memory T cells. MAL– T cells proliferate strongly in response to stimulation with CD3/CD28 antibodies, corroborating that MAL+ T cells are naïve and MAL– T cells memory subtypes. Further, resting MAL– T cells harbor a larger pool of Ser59‐ and Tyr394‐ double phosphorylated lymphocyte‐specific kinase (Lck), which is rapidly increased upon in vitro restimulation. Previously, lack of MAL was reported to prevent transport of Lck, the key protein tyrosine kinase of TCR/CD3 signaling to the cell membrane, and to result in strongly impaired human T cell activation. Here, we show that knocking out MAL did not significantly affect Lck membrane localization and immune synapse recruitment, or transcriptional T cell activation. Collectively, our results indicate that loss of MAL is associated with activation‐induced differentiation of human T cells but not with impaired membrane localization of Lck or TCR signaling capacity.
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Affiliation(s)
- Judith Leitner
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Kodchakorn Mahasongkram
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Philipp Schatzlmaier
- Institute for Hygiene and Applied Immunology, Centre for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Karin Pfisterer
- Institute for Hygiene and Applied Immunology, Centre for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Vladimir Leksa
- Institute for Hygiene and Applied Immunology, Centre for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,Laboratory of Molecular Immunology, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Supansa Pata
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Biomedical Technology Research Centre, National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Watchara Kasinrerk
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Biomedical Technology Research Centre, National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Hannes Stockinger
- Institute for Hygiene and Applied Immunology, Centre for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Peter Steinberger
- Division of Immune Receptors and T Cell Activation, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
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5
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Kästle M, Merten C, Hartig R, Kaehne T, Liaunardy-Jopeace A, Woessner NM, Schamel WW, James J, Minguet S, Simeoni L, Schraven B. Tyrosine 192 within the SH2 domain of the Src-protein tyrosine kinase p56 Lck regulates T-cell activation independently of Lck/CD45 interactions. Cell Commun Signal 2020; 18:183. [PMID: 33225946 PMCID: PMC7682018 DOI: 10.1186/s12964-020-00673-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/13/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Upon engagement of the T-cell receptor (TCR), the Src-family protein tyrosine kinase p56Lck phosphorylates components of the TCR (e.g. the TCRζ chains), thereby initiating T-cell activation. The enzymatic activity of Lck is primarily regulated via reversible and dynamic phosphorylation of two tyrosine residues, Y394 and Y505. Lck possesses an additional highly conserved tyrosine Y192, located within the SH2 domain, whose role in T-cell activation is not fully understood. METHODS Knock-in mice expressing a phospho-mimetic (Y192E) form of Lck were generated. Cellular and biochemical characterization was performed to elucidate the function of Y192 in primary T cells. HEK 293T and Jurkat T cells were used for in vitro studies. RESULTS Co-immunoprecipitation studies and biochemical analyses using T cells from LckY192E knock-in mice revealed a diminished binding of LckY192E to CD45 and a concomitant hyperphosphorylation of Y505, thus corroborating previous data obtained in Jurkat T cells. Surprisingly however, in vitro kinase assays showed that LckY192E possesses a normal enzymatic activity in human and murine T cells. FLIM/FRET measurements employing an LckY192E biosensor further indicated that the steady state conformation of the LckY192E mutant is similar to Lckwt. These data suggest that Y192 might regulate Lck functions also independently from the Lck/CD45-association. Indeed, when LckY192E was expressed in CD45-/-/Csk-/- non-T cells (HEK 293T cells), phosphorylation of Y505 was similar to Lckwt, but LckY192E still failed to optimally phosphorylate and activate the Lck downstream substrate ZAP70. Furthermore, LckY19E was recruited less to CD3 after TCR stimulation. CONCLUSIONS Taken together, phosphorylation of Y192 regulates Lck functions in T cells at least twofold, by preventing Lck association to CD45 and by modulating ligand-induced recruitment of Lck to the TCR. MAJOR FINDINGS Our data change the current view on the function of Y192 and suggest that Y192 also regulates Lck activity in a manner independent of Y505 phosphorylation. Video Abstract.
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Affiliation(s)
- Matthias Kästle
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, Leipziger Str.44, Building 26, 39120, Magdeburg, Germany.,Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Camilla Merten
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, Leipziger Str.44, Building 26, 39120, Magdeburg, Germany.,Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Roland Hartig
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, Leipziger Str.44, Building 26, 39120, Magdeburg, Germany.,Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Thilo Kaehne
- Institute of Experimental Internal Medicine, Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | | | - Nadine M Woessner
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center of Chronic Immunodeficiency CCI, University Clinics and Medical Faculty, Freiburg, Germany
| | - Wolfgang W Schamel
- Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center of Chronic Immunodeficiency CCI, University Clinics and Medical Faculty, Freiburg, Germany
| | - John James
- Molecular Immunity Unit, Department of Medicine, University of Cambridge, MRC-LMB, Cambridge, UK.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill, Coventry, UK
| | - Susana Minguet
- Faculty of Biology, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center of Chronic Immunodeficiency CCI, University Clinics and Medical Faculty, Freiburg, Germany
| | - Luca Simeoni
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, Leipziger Str.44, Building 26, 39120, Magdeburg, Germany. .,Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany.
| | - Burkhart Schraven
- Institute of Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University, Leipziger Str.44, Building 26, 39120, Magdeburg, Germany. .,Health Campus Immunology, Infectiology and Inflammation (GC-I3), Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany.
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6
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Chua XY, Aballo T, Elnemer W, Tran M, Salomon A. Quantitative Interactomics of Lck-TurboID in Living Human T Cells Unveils T Cell Receptor Stimulation-Induced Proximal Lck Interactors. J Proteome Res 2020; 20:715-726. [PMID: 33185455 DOI: 10.1021/acs.jproteome.0c00616] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
While Lck has been widely recognized to play a pivotal role in the initiation of the T cell receptor (TCR) signaling pathway, an understanding of the precise regulation of Lck in T cells upon TCR activation remains elusive. Investigation of protein-protein interaction (PPI) using proximity labeling techniques such as TurboID has the potential to provide valuable molecular insights into Lck regulatory networks. By expressing Lck-TurboID in Jurkat T cells, we have uncovered a dynamic, short-range Lck protein interaction network upon 30 min of TCR stimulation. In this novel application of TurboID, we detected 27 early signaling-induced Lck-proximal interactors in living T cells, including known and novel Lck interactors, validating the discovery power of this tool. Our results revealed previously unappreciated Lck PPI which may be associated with cytoskeletal rearrangement, ubiquitination of TCR signaling proteins, activation of the mitogen-activated protein kinase cascade, coalescence of the LAT signalosome, and formation of the immunological synapse. In this study, we demonstrated for the first time in immune cells and for the kinase Lck that TurboID can be utilized to unveil PPI dynamics in living cells at a time scale consistent with early TCR signaling. Data are available via ProteomeXchange with identifier PXD020759.
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Affiliation(s)
- Xien Yu Chua
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island, United States
| | - Timothy Aballo
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, United States
| | - William Elnemer
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, United States
| | - Melanie Tran
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, United States
| | - Arthur Salomon
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, United States
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7
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Zhang X, Mariano CF, Ando Y, Shen K. Bioengineering tools for probing intracellular events in T lymphocytes. WIREs Mech Dis 2020; 13:e1510. [PMID: 33073545 DOI: 10.1002/wsbm.1510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 11/11/2022]
Abstract
T lymphocytes are the central coordinator and executor of many immune functions. The activation and function of T lymphocytes are mediated through the engagement of cell surface receptors and regulated by a myriad of intracellular signaling network. Bioengineering tools, including imaging modalities and fluorescent probes, have been developed and employed to elucidate the cellular events throughout the functional lifespan of T cells. A better understanding of these events can broaden our knowledge in the immune systems biology, as well as accelerate the development of effective diagnostics and immunotherapies. Here we review the commonly used and recently developed techniques and probes for monitoring T lymphocyte intracellular events, following the order of intracellular events in T cells from activation, signaling, metabolism to apoptosis. The techniques introduced here can be broadly applied to other immune cells and cell systems. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Immune System Diseases > Biomedical Engineering Infectious Diseases > Biomedical Engineering.
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Affiliation(s)
- Xinyuan Zhang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Chelsea F Mariano
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Yuta Ando
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Keyue Shen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.,Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, USA.,USC Stem Cell, University of Southern California, Los Angeles, California, USA
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8
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Hilzenrat G, Pandžić E, Yang Z, Nieves DJ, Goyette J, Rossy J, Ma Y, Gaus K. Conformational States Control Lck Switching between Free and Confined Diffusion Modes in T Cells. Biophys J 2020; 118:1489-1501. [PMID: 32097620 PMCID: PMC7091564 DOI: 10.1016/j.bpj.2020.01.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 11/13/2022] Open
Abstract
T cell receptor phosphorylation by Lck is an essential step in T cell activation. It is known that the conformational states of Lck control enzymatic activity; however, the underlying principles of how Lck finds its substrate over the plasma membrane remain elusive. Here, single-particle tracking is paired with photoactivatable localization microscopy to observe the diffusive modes of Lck in the plasma membrane. Individual Lck molecules switched between free and confined diffusion in both resting and stimulated T cells. Lck mutants locked in the open conformation were more confined than Lck mutants in the closed conformation. Further confinement of kinase-dead versions of Lck suggests that Lck confinement was not caused by phosphorylated substrates. Our data support a model in which confined diffusion of open Lck results in high local phosphorylation rates, and inactive, closed Lck diffuses freely to enable long-range distribution over the plasma membrane.
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Affiliation(s)
- Geva Hilzenrat
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia; Commonwealth Scientific and Industry Research Organization (CSIRO), Manufacturing, Clayton, Victoria, Australia
| | - Elvis Pandžić
- BioMedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia
| | - Zhengmin Yang
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
| | - Daniel J Nieves
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia; Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
| | - Jérémie Rossy
- Biotechnology Institute Thurgau, University of Konstanz, Kreuzlingen, Switzerland
| | - Yuanqing Ma
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia.
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9
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Mukherjee A, Singh R, Udayan S, Biswas S, Reddy PP, Manmadhan S, George G, Kumar S, Das R, Rao BM, Gulyani A. A Fyn biosensor reveals pulsatile, spatially localized kinase activity and signaling crosstalk in live mammalian cells. eLife 2020; 9:50571. [PMID: 32017701 PMCID: PMC7000222 DOI: 10.7554/elife.50571] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 01/08/2020] [Indexed: 12/14/2022] Open
Abstract
Cell behavior is controlled through spatio-temporally localized protein activity. Despite unique and often contradictory roles played by Src-family-kinases (SFKs) in regulating cell physiology, activity patterns of individual SFKs have remained elusive. Here, we report a biosensor for specifically visualizing active conformation of SFK-Fyn in live cells. We deployed combinatorial library screening to isolate a binding-protein (F29) targeting activated Fyn. Nuclear-magnetic-resonance (NMR) analysis provides the structural basis of F29 specificity for Fyn over homologous SFKs. Using F29, we engineered a sensitive, minimally-perturbing fluorescence-resonance-energy-transfer (FRET) biosensor (FynSensor) that reveals cellular Fyn activity to be spatially localized, pulsatile and sensitive to adhesion/integrin signaling. Strikingly, growth factor stimulation further enhanced Fyn activity in pre-activated intracellular zones. However, inhibition of focal-adhesion-kinase activity not only attenuates Fyn activity, but abolishes growth-factor modulation. FynSensor imaging uncovers spatially organized, sensitized signaling clusters, direct crosstalk between integrin and growth-factor-signaling, and clarifies how compartmentalized Src-kinase activity may drive cell fate.
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Affiliation(s)
- Ananya Mukherjee
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India.,SASTRA University, Thanjavur, India
| | - Randhir Singh
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | - Sreeram Udayan
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | - Sayan Biswas
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | | | - Saumya Manmadhan
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | - Geen George
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | - Shilpa Kumar
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
| | - Ranabir Das
- National Centre for Biological Sciences, Bangalore, India
| | - Balaji M Rao
- North Carolina State University, Raleigh, United States
| | - Akash Gulyani
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
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10
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Koudelková L, Pataki AC, Tolde O, Pavlik V, Nobis M, Gemperle J, Anderson K, Brábek J, Rosel D. Novel FRET-Based Src Biosensor Reveals Mechanisms of Src Activation and Its Dynamics in Focal Adhesions. Cell Chem Biol 2019; 26:255-268.e4. [DOI: 10.1016/j.chembiol.2018.10.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 09/12/2018] [Accepted: 10/26/2018] [Indexed: 10/27/2022]
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11
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 295] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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12
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Periasamy J, Kurdekar V, Jasti S, Nijaguna MB, Boggaram S, Hurakadli MA, Raina D, Kurup LM, Chintha C, Manjunath K, Goyal A, Sadasivam G, Bharatham K, Padigaru M, Potluri V, Venkitaraman AR. Targeting Phosphopeptide Recognition by the Human BRCA1 Tandem BRCT Domain to Interrupt BRCA1-Dependent Signaling. Cell Chem Biol 2018; 25:677-690.e12. [PMID: 29606576 PMCID: PMC6015222 DOI: 10.1016/j.chembiol.2018.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/24/2017] [Accepted: 02/22/2018] [Indexed: 02/06/2023]
Abstract
Intracellular signals triggered by DNA breakage flow through proteins containing BRCT (BRCA1 C-terminal) domains. This family, comprising 23 conserved phosphopeptide-binding modules in man, is inaccessible to small-molecule chemical inhibitors. Here, we develop Bractoppin, a drug-like inhibitor of phosphopeptide recognition by the human BRCA1 tandem (t)BRCT domain, which selectively inhibits substrate binding with nanomolar potency in vitro. Structure-activity exploration suggests that Bractoppin engages BRCA1 tBRCT residues recognizing pSer in the consensus motif, pSer-Pro-Thr-Phe, plus an abutting hydrophobic pocket that is distinct in structurally related BRCT domains, conferring selectivity. In cells, Bractoppin inhibits substrate recognition detected by Förster resonance energy transfer, and diminishes BRCA1 recruitment to DNA breaks, in turn suppressing damage-induced G2 arrest and assembly of the recombinase, RAD51. But damage-induced MDC1 recruitment, single-stranded DNA (ssDNA) generation, and TOPBP1 recruitment remain unaffected. Thus, an inhibitor of phosphopeptide recognition selectively interrupts BRCA1 tBRCT-dependent signals evoked by DNA damage. Bractoppin selectively blocks phosphopeptide recognition by the BRCA1 tBRCT domain Bractoppin engages tBRCT residues recognizing pSer, plus an adjacent pocket Bractoppin interrupts BRCA1 tBRCT-dependent cellular signals evoked by DNA damage This work opens avenues to inhibit intracellular signaling by the tBRCT domain family
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Affiliation(s)
- Jayaprakash Periasamy
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vadiraj Kurdekar
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Subbarao Jasti
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Mamatha B Nijaguna
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Sanjana Boggaram
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Manjunath A Hurakadli
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Dhruv Raina
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Lokavya Meenakshi Kurup
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Chetan Chintha
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavyashree Manjunath
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Aneesh Goyal
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Gayathri Sadasivam
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavitha Bharatham
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Muralidhara Padigaru
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vijay Potluri
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Ashok R Venkitaraman
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India; Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK.
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13
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Dissection of Protein Kinase Pathways in Live Cells Using Photoluminescent Probes: Surveillance or Interrogation? CHEMOSENSORS 2018. [DOI: 10.3390/chemosensors6020019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Simeoni L. Lck activation: puzzling the pieces together. Oncotarget 2017; 8:102761-102762. [PMID: 29262519 PMCID: PMC5732685 DOI: 10.18632/oncotarget.22309] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/04/2017] [Indexed: 11/25/2022] Open
Affiliation(s)
- Luca Simeoni
- Luca Simeoni: Otto-von-Guericke University, Institute of Molecular and Clinical Immunology, Magdeburg, Germany
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15
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Liaunardy-Jopeace A, Murton BL, Mahesh M, Chin JW, James JR. Encoding optical control in LCK kinase to quantitatively investigate its activity in live cells. Nat Struct Mol Biol 2017; 24:1155-1163. [PMID: 29083415 PMCID: PMC5736103 DOI: 10.1038/nsmb.3492] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 09/25/2017] [Indexed: 11/16/2022]
Abstract
LCK is a tyrosine kinase essential for initiating T-cell antigen receptor (TCR) signaling. A complete understanding of LCK function is constrained by a paucity of methods to quantitatively study its function within live cells. To address this limitation, we generated LCK*, in which a key active site lysine is replaced by a photo-caged equivalent, using genetic code expansion. This enabled fine temporal and spatial control over kinase activity, allowing us to quantify phosphorylation kinetics in situ using biochemical and imaging approaches. We find that auto-phosphorylation of the LCK active site loop is indispensable for its catalytic activity and that LCK can stimulate its own activation by adopting a more open conformation, which can be modulated by point mutations. We then show that CD4 and CD8, the T cell coreceptors, can enhance LCK activity, helping to explain their effect in physiological TCR signaling. Our approach also provides general insights into SRC-family kinase dynamics.
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Affiliation(s)
| | - Ben L Murton
- Molecular Immunity Unit, Department of Medicine, University of Cambridge, MRC-LMB, Cambridge, UK
| | - Mohan Mahesh
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
| | - John R James
- Molecular Immunity Unit, Department of Medicine, University of Cambridge, MRC-LMB, Cambridge, UK
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16
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Philipsen L, Reddycherla AV, Hartig R, Gumz J, Kästle M, Kritikos A, Poltorak MP, Prokazov Y, Turbin E, Weber A, Zuschratter W, Schraven B, Simeoni L, Müller AJ. De novo phosphorylation and conformational opening of the tyrosine kinase Lck act in concert to initiate T cell receptor signaling. Sci Signal 2017; 10:10/462/eaaf4736. [DOI: 10.1126/scisignal.aaf4736] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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17
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Ballek O, Valečka J, Dobešová M, Broučková A, Manning J, Řehulka P, Stulík J, Filipp D. TCR Triggering Induces the Formation of Lck-RACK1-Actinin-1 Multiprotein Network Affecting Lck Redistribution. Front Immunol 2016; 7:449. [PMID: 27833610 PMCID: PMC5081367 DOI: 10.3389/fimmu.2016.00449] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/10/2016] [Indexed: 02/02/2023] Open
Abstract
The initiation of T-cell signaling is critically dependent on the function of the member of Src family tyrosine kinases, Lck. Upon T-cell antigen receptor (TCR) triggering, Lck kinase activity induces the nucleation of signal-transducing hubs that regulate the formation of complex signaling network and cytoskeletal rearrangement. In addition, the delivery of Lck function requires rapid and targeted membrane redistribution, but the mechanism underpinning this process is largely unknown. To gain insight into this process, we considered previously described proteins that could assist in this process via their capacity to interact with kinases and regulate their intracellular translocations. An adaptor protein, receptor for activated C kinase 1 (RACK1), was chosen as a viable option, and its capacity to bind Lck and aid the process of activation-induced redistribution of Lck was assessed. Our microscopic observation showed that T-cell activation induces a rapid, concomitant, and transient co-redistribution of Lck and RACK1 into the forming immunological synapse. Consistent with this observation, the formation of transient RACK1-Lck complexes were detectable in primary CD4+ T-cells with their maximum levels peaking 10 s after TCR-CD4 co-aggregation. Moreover, RACK1 preferentially binds to a pool of kinase active pY394Lck, which co-purifies with high molecular weight cellular fractions. The formation of RACK1-Lck complexes depends on functional SH2 and SH3 domains of Lck and includes several other signaling and cytoskeletal elements that transiently bind the complex. Notably, the F-actin-crosslinking protein, α-actinin-1, binds to RACK1 only in the presence of kinase active Lck suggesting that the formation of RACK1-pY394Lck-α-actinin-1 complex serves as a signal module coupling actin cytoskeleton bundling with productive TCR/CD4 triggering. In addition, the treatment of CD4+ T-cells with nocodazole, which disrupts the microtubular network, also blocked the formation of RACK1-Lck complexes. Importantly, activation-induced Lck redistribution was diminished in primary CD4+ T-cells by an adenoviral-mediated knockdown of RACK1. These results demonstrate that in T cells, RACK1, as an essential component of the multiprotein complex which upon TCR engagement, links the binding of kinase active Lck to elements of the cytoskeletal network and affects the subcellular redistribution of Lck.
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Affiliation(s)
- Ondřej Ballek
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
| | - Jan Valečka
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
| | - Martina Dobešová
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
| | - Adéla Broučková
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
| | - Jasper Manning
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
| | - Pavel Řehulka
- Faculty of Military Health Sciences, Institute of Molecular Pathology , Hradec Králové , Czech Republic
| | - Jiří Stulík
- Faculty of Military Health Sciences, Institute of Molecular Pathology , Hradec Králové , Czech Republic
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR , Prague , Czech Republic
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Baumgart F, Arnold A, Leskovar K, Staszek K, Fölser M, Weghuber J, Stockinger H, Schütz GJ. Varying label density allows artifact-free analysis of membrane-protein nanoclusters. Nat Methods 2016; 13:661-4. [PMID: 27295310 PMCID: PMC6404959 DOI: 10.1038/nmeth.3897] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/17/2016] [Indexed: 12/14/2022]
Abstract
We present a method to robustly discriminate clustered from randomly distributed molecules detected with techniques based on single-molecule localization microscopy, such as PALM and STORM. The approach is based on deliberate variation of labeling density, such as titration of fluorescent antibody, combined with quantitative cluster analysis, and it thereby circumvents the problem of cluster artifacts generated by overcounting of blinking fluorophores. The method was used to analyze nanocluster formation in resting and activated immune cells.
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Affiliation(s)
| | | | | | - Kaj Staszek
- Institute of Applied Physics, TU Wien, Vienna, Austria
| | - Martin Fölser
- Institute of Applied Physics, TU Wien, Vienna, Austria
| | - Julian Weghuber
- School of Engineering and Environmental Sciences, University of Applied Sciences Upper Austria, Wels, Austria
| | - Hannes Stockinger
- Institute for Hygiene and Applied Immunology, Medical University of Vienna, Vienna, Austria
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Abstract
Lipid rafts are defined as cholesterol- and sphingomyelin-enriched membrane domains in the plasma membrane of cells that are highly dynamic and cannot be resolved with conventional light microscopy. Membrane proteins that are embedded in the phospholipid matrix can be grouped into raft and non-raft proteins based on their association with detergent-resistant membranes in biochemical assays. Selective lipid-protein interactions not only produce heterogeneity in the membrane, but also cause the spatial compartmentalization of membrane reactions. It has been proposed that lipid rafts function as platforms during cell signalling transduction processes such as T-cell activation (see Chapter 13 (pages 165-175)). It has been proposed that raft association co-localizes specific signalling proteins that may yield the formation of the observed signalling microclusters at the immunological synapses. However, because of the nanometre size and high dynamics of lipid rafts, direct observations have been technically challenging, leading to an ongoing discussion of the lipid raft model and its alternatives. Recent developments in fluorescence imaging techniques have provided new opportunities to investigate the organization of cell membranes with unprecedented spatial resolution. In this chapter, we describe the concept of the lipid raft and alternative models and how new imaging technologies have advanced these concepts.
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20
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Hochreiter B, Garcia AP, Schmid JA. Fluorescent proteins as genetically encoded FRET biosensors in life sciences. SENSORS 2015; 15:26281-314. [PMID: 26501285 PMCID: PMC4634415 DOI: 10.3390/s151026281] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/08/2015] [Indexed: 12/11/2022]
Abstract
Fluorescence- or Förster resonance energy transfer (FRET) is a measurable physical energy transfer phenomenon between appropriate chromophores, when they are in sufficient proximity, usually within 10 nm. This feature has made them incredibly useful tools for many biomedical studies on molecular interactions. Furthermore, this principle is increasingly exploited for the design of biosensors, where two chromophores are linked with a sensory domain controlling their distance and thus the degree of FRET. The versatility of these FRET-biosensors made it possible to assess a vast amount of biological variables in a fast and standardized manner, allowing not only high-throughput studies but also sub-cellular measurements of biological processes. In this review, we aim at giving an overview over the recent advances in genetically encoded, fluorescent-protein based FRET-biosensors, as these represent the largest and most vividly growing group of FRET-based sensors. For easy understanding, we are grouping them into four categories, depending on their molecular mechanism. These are based on: (a) cleavage; (b) conformational-change; (c) mechanical force and (d) changes in the micro-environment. We also address the many issues and considerations that come with the development of FRET-based biosensors, as well as the possibilities that are available to measure them.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Alan Pardo Garcia
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Johannes A Schmid
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
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21
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Manz BN, Tan YX, Courtney AH, Rutaganira F, Palmer E, Shokat KM, Weiss A. Small molecule inhibition of Csk alters affinity recognition by T cells. eLife 2015; 4. [PMID: 26302204 PMCID: PMC4568592 DOI: 10.7554/elife.08088] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/22/2015] [Indexed: 12/12/2022] Open
Abstract
The C-terminal Src kinase (Csk), the primary negative regulator of Src-family kinases (SFK), plays a crucial role in controlling basal and inducible receptor signaling. To investigate how Csk activity regulates T cell antigen receptor (TCR) signaling, we utilized a mouse expressing mutated Csk (CskAS) whose catalytic activity is specifically and rapidly inhibited by a small molecule. Inhibition of CskAS during TCR stimulation led to stronger and more prolonged TCR signaling and to increased proliferation. Inhibition of CskAS enhanced activation by weak but strictly cognate agonists. Titration of Csk inhibition revealed that a very small increase in SFK activity was sufficient to potentiate T cell responses to weak agonists. Csk plays an important role, not only in basal signaling, but also in setting the TCR signaling threshold and affinity recognition. DOI:http://dx.doi.org/10.7554/eLife.08088.001 The immune system has ‘T’ cells that recognize when the body is infected with a virus or bacterium and mount an immune response that is targeted to that microbe. They can also find and eliminate cancer cells. The microbes and cancer cells produce molecules called antigens that are detected by proteins on the surface of the T cell called T cell receptors (TCR). Antigen recognition causes the TCRs to transmit signals to the inside of the T cell that trigger an immune response. The degree to which the TCRs are active, and the length of time that they transmit signals regulates the size of the immune response. Therefore, developing new drugs that manipulate the activity of TCRs could be useful to treat many diseases. An enzyme called Csk inhibits the activities of a small family of proteins involved in a variety of different processes. One protein that Csk targets is called Lck and is required for the activation of immune responses in T cells. However, it is not clear whether Csk interacting with this protein stops the release of signals from TCRs, or whether it alters the level to which TCRs need to be activated before they transmit the signals. Manz, Tan et al. studied T cells from mice that had a mutant form of Csk that is inhibited by a drug called 3-iodo-benzyl-PP1 (3-IB-PP1), but otherwise works normally. When these cells detected an antigen in the presence of the drug, its TCRs were more highly activated and transmitted signals for a longer period of time than cells not exposed to the drug. The drug especially enhanced immune responses to very weak antigens, ones that might not activate T cells under normal circumstances. Manz, Tan et al.'s findings confirm that Csk plays a negative role in the activation of T cells and suggest that Csk may be a useful target for drug therapies that aim to fine-tune immune responses. The next challenge is to find a drug that can inhibit normal Csk enzymes and test this in mice and other animals. DOI:http://dx.doi.org/10.7554/eLife.08088.002
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Affiliation(s)
- Boryana N Manz
- Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Ying Xim Tan
- Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Adam H Courtney
- Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Florentine Rutaganira
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Ed Palmer
- Departments of Biomedicine and Nephrology, University Hospital Basel, University of basel, Basel, Switzerland
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Arthur Weiss
- Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, University of California, San Francisco, San Francisco, United States
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In Vivo nonlinear optical imaging of immune responses: tissue injury and infection. Biophys J 2015; 107:2436-43. [PMID: 25418312 DOI: 10.1016/j.bpj.2014.09.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/24/2014] [Accepted: 09/09/2014] [Indexed: 12/25/2022] Open
Abstract
In this study, we demonstrate a noninvasive imaging approach based on multimodal nonlinear optical microscopy to in vivo image the responses of immune cells (neutrophils) to the tissue injury and bacterial infection in a zebrafish model. Specifically, the second harmonic generation from myosin thick filaments in sarcomere enabled a clear visualization of the muscle injury and infection. Two-photon excited fluorescence was used to track the behavior of the neutrophils that were transgenically labeled by red fluorescent protein. The corresponding reduced nicotinamide adenine dinucleotide (NADH) two-photon excited fluorescence images revealed a detailed morphological transformation process of individual neutrophils during muscle tissue injury and bacterial infection. The analysis of time-resolved NADH signals from the neutrophils provided important biological insights of the cellular energy metabolism during the immune responses. We found a significant increase of free/protein-bound NADH ratios in activated neutrophils in bacterial-infected tissue. In this study, we also discovered that, under 720 nm excitation, two wild-type strains (DH5? and BL21) of bacteria Escherichia coli emitted distinct endogenous fluorescence of double-peak at ?450 and ?520 nm, respectively. We demonstrated that the double-peak fluorescence signal could be used to differentiate the E. coli from surrounding tissues of dominant NADH signals, and to achieve label-free tracking of E. coli bacteria in vivo.
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23
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Lhuillier C, Barjon C, Niki T, Gelin A, Praz F, Morales O, Souquere S, Hirashima M, Wei M, Dellis O, Busson P. Impact of Exogenous Galectin-9 on Human T Cells: CONTRIBUTION OF THE T CELL RECEPTOR COMPLEX TO ANTIGEN-INDEPENDENT ACTIVATION BUT NOT TO APOPTOSIS INDUCTION. J Biol Chem 2015; 290:16797-811. [PMID: 25947381 DOI: 10.1074/jbc.m115.661272] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Indexed: 11/06/2022] Open
Abstract
Galectin-9 (gal-9) is a multifunctional β-galactoside-binding lectin, frequently released in the extracellular medium, where it acts as a pleiotropic immune modulator. Despite its overall immunosuppressive effects, a recent study has reported bimodal action of gal-9 on human resting blood T cells with apoptosis occurring in the majority of them, followed by a wave of activation and expansion of Th1 cells in the surviving population. Our knowledge of the signaling events triggered by exogenous gal-9 in T cells remains limited. One of these events is cytosolic calcium (Ca(2+)) release reported in some murine and human T cells. The aim of this study was to investigate the contribution of Ca(2+) mobilization to apoptotic and nonapoptotic effects of exogenous gal-9 in human T cells. We found that the T cell receptor (TCR)-CD3 complex and the Lck kinase were required for Ca(2+) mobilization but not for apoptosis induction in Jurkat cells. These data were confirmed in human CD4(+) T cells from peripheral blood as follows: a specific Lck chemical inhibitor abrogated Ca(2+) mobilization but not apoptosis induction. Moreover, Lck activity was also required for the production of Th1-type cytokines, i.e. interleukin-2 and interferon-γ, which resulted from gal-9 stimulation in peripheral CD4(+) T cells. These findings indicate that gal-9 acts on T cells by two distinct pathways as follows: one mimicking antigen-specific activation of the TCR with a mandatory contribution of proximal elements of the TCR complex, especially Lck, and another resulting in apoptosis that is independent of this complex.
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Affiliation(s)
- Claire Lhuillier
- From the Université Paris-Sud, 15 Rue Georges Clémenceau, 91400, Orsay, France, the CNRS, UMR 8126, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94805 Villejuif Cedex, France, the Cellvax, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort Cedex, France
| | - Clément Barjon
- From the Université Paris-Sud, 15 Rue Georges Clémenceau, 91400, Orsay, France, the CNRS, UMR 8126, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94805 Villejuif Cedex, France, the Cellvax, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort Cedex, France
| | - Toshiro Niki
- the Department of Immunology and Immunopathology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan, the GalPharma Co., Ltd., Takamatsu, Kagawa 761-0301, Japan
| | - Aurore Gelin
- the CNRS, UMR 8126, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94805 Villejuif Cedex, France
| | - Françoise Praz
- INSERM, UMR-S 938, Centre de Recherche Saint-Antoine, 75012, Paris, France, the Sorbonne Universités, UPMC Université Paris 06, UMR-S 938, Centre de Recherche Saint-Antoine, 75012, Paris, France
| | - Olivier Morales
- CNRS, UMR 8161 Groupe IRCV, Institut de Biologie de Lille, 1 Rue du Pr. Calmette, 59021 Lille, France
| | - Sylvie Souquere
- From the Université Paris-Sud, 15 Rue Georges Clémenceau, 91400, Orsay, France, UMR 8122, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94805 Villejuif Cedex, France, and
| | - Mitsuomi Hirashima
- the Department of Immunology and Immunopathology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan, the GalPharma Co., Ltd., Takamatsu, Kagawa 761-0301, Japan
| | - Ming Wei
- the Cellvax, Ecole Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort Cedex, France
| | - Olivier Dellis
- From the Université Paris-Sud, 15 Rue Georges Clémenceau, 91400, Orsay, France, INSERM, UMR-S 757, Bâtiment 440/443, Rue des Adèles, 91405 Orsay, France
| | - Pierre Busson
- From the Université Paris-Sud, 15 Rue Georges Clémenceau, 91400, Orsay, France, the CNRS, UMR 8126, Institut Gustave Roussy, 114 Rue Edouard Vaillant, 94805 Villejuif Cedex, France,
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The coreceptor CD4 is expressed in distinct nanoclusters and does not colocalize with T-cell receptor and active protein tyrosine kinase p56lck. Proc Natl Acad Sci U S A 2015; 112:E1604-13. [PMID: 25829544 DOI: 10.1073/pnas.1503532112] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
CD4 molecules on the surface of T lymphocytes greatly augment the sensitivity and activation process of these cells, but how it functions is not fully understood. Here we studied the spatial organization of CD4, and its relationship to T-cell antigen receptor (TCR) and the active form of Src kinase p56lck (Lck) using single and dual-color photoactivated localization microscopy (PALM) and direct stochastic optical reconstruction microscopy (dSTORM). In nonactivated T cells, CD4 molecules are clustered in small protein islands, as are TCR and Lck. By dual-color imaging, we find that CD4, TCR, and Lck are localized in their separate clusters with limited interactions in the interfaces between them. Upon T-cell activation, the TCR and CD4 begin clustering together, developing into microclusters, and undergo a larger scale redistribution to form supramolecluar activation clusters (SMACs). CD4 and Lck localize in the inner TCR region of the SMAC, but this redistribution of disparate cluster structures results in enhanced segregation from each other. In nonactivated cells these preclustered structures and the limited interactions between them may serve to limit spontaneous and random activation events. However, the small sizes of these island structures also ensure large interfacial surfaces for potential interactions and signal amplification when activation is initiated. In the later activation stages, the increasingly larger clusters and their segregation from each other reduce the interfacial surfaces and could have a dampening effect. These highly differentiated spatial distributions of TCR, CD4, and Lck and their changes during activation suggest that there is a more complex hierarchy than previously thought.
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Ligand-engaged TCR is triggered by Lck not associated with CD8 coreceptor. Nat Commun 2014; 5:5624. [PMID: 25427562 PMCID: PMC4248239 DOI: 10.1038/ncomms6624] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 10/20/2014] [Indexed: 11/28/2022] Open
Abstract
The earliest molecular events in T cell recognition have not yet been fully described, and the initial T cell receptor (TCR) triggering mechanism remains a subject of controversy. Here, using TIRF/FRET microscopy, we observe a two-stage interaction between TCR, CD8, and MHCp. There is an early (within seconds) interaction between CD3ζ and the coreceptor CD8 that is independent of the binding of CD8 to MHC, but that requires CD8 association with Lck. Later (several minutes) CD3ζ-CD8 interactions require CD8-MHC binding. Lck can be found free or bound to the coreceptor. This work indicates that the initial TCR triggering event is induced by free Lck.
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Ballek O, Valečka J, Manning J, Filipp D. The pool of preactivated Lck in the initiation of T-cell signaling: a critical re-evaluation of the Lck standby model. Immunol Cell Biol 2014; 93:384-95. [PMID: 25420722 DOI: 10.1038/icb.2014.100] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 12/23/2022]
Abstract
The initiation of T-cell receptor (TCR) signaling, based on the cobinding of TCR and CD4-Lck heterodimer to a peptide-major histocompatibility complex II on antigen presenting cells, represents a classical model of T-cell signaling. What is less clear however, is the mechanism which translates TCR engagement to the phosphorylation of immunoreceptor tyrosine-based activation motifs on CD3 chains and how this event is coupled to the delivery of Lck function. Recently proposed 'standby model of Lck' posits that resting T-cells contain an abundant pool of constitutively active Lck (pY394(Lck)) required for TCR triggering, and this amount, upon TCR engagement, remains constant. Here, we show that although maintenance of the limited pool of pY394(Lck) is necessary for the generation of TCR proximal signals in a time-restricted fashion, the total amount of this pool, ~2%, is much smaller than previously reported (~40%). We provide evidence that this dramatic discrepancy in the content of pY394(Lck)is likely the consequence of spontaneous phosphorylation of Lck that occurred after cell solubilization. Additional discrepancies can be accounted for by the sensitivity of different pY394(Lck)-specific antibodies and the type of detergents used. These data suggest that reagents and conditions used for the quantification of signaling parameters must be carefully validated and interpreted. Thus, the limited size of pY394(Lck) pool in primary T-cells invites a discussion regarding the adjustment of the quantitative parameters of the standby model of Lck and reevaluation of the mechanism by which this pool contributes to the generation of proximal TCR signaling.
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Affiliation(s)
- Ondřej Ballek
- 1] Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic [2] Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jan Valečka
- 1] Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic [2] Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jasper Manning
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic
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Chylek LA, Akimov V, Dengjel J, Rigbolt KTG, Hu B, Hlavacek WS, Blagoev B. Phosphorylation site dynamics of early T-cell receptor signaling. PLoS One 2014; 9:e104240. [PMID: 25147952 PMCID: PMC4141737 DOI: 10.1371/journal.pone.0104240] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/07/2014] [Indexed: 11/18/2022] Open
Abstract
In adaptive immune responses, T-cell receptor (TCR) signaling impacts multiple cellular processes and results in T-cell differentiation, proliferation, and cytokine production. Although individual protein-protein interactions and phosphorylation events have been studied extensively, we lack a systems-level understanding of how these components cooperate to control signaling dynamics, especially during the crucial first seconds of stimulation. Here, we used quantitative proteomics to characterize reshaping of the T-cell phosphoproteome in response to TCR/CD28 co-stimulation, and found that diverse dynamic patterns emerge within seconds. We detected phosphorylation dynamics as early as 5 s and observed widespread regulation of key TCR signaling proteins by 30 s. Development of a computational model pointed to the presence of novel regulatory mechanisms controlling phosphorylation of sites with central roles in TCR signaling. The model was used to generate predictions suggesting unexpected roles for the phosphatase PTPN6 (SHP-1) and shortcut recruitment of the actin regulator WAS. Predictions were validated experimentally. This integration of proteomics and modeling illustrates a novel, generalizable framework for solidifying quantitative understanding of a signaling network and for elucidating missing links.
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Affiliation(s)
- Lily A. Chylek
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Vyacheslav Akimov
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Jörn Dengjel
- Department of Dermatology, Medical Center; Freiburg Institute for Advanced Studies (FRIAS); BIOSS Centre for Biological Signalling Studies; ZBSA Center for Biological Systems Analysis, University of Freiburg, Freiburg, Germany
| | - Kristoffer T. G. Rigbolt
- Department of Dermatology, Medical Center; Freiburg Institute for Advanced Studies (FRIAS); BIOSS Centre for Biological Signalling Studies; ZBSA Center for Biological Systems Analysis, University of Freiburg, Freiburg, Germany
| | - Bin Hu
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - William S. Hlavacek
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Blagoy Blagoev
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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Pfisterer K, Forster F, Paster W, Supper V, Ohradanova-Repic A, Eckerstorfer P, Zwirzitz A, Donner C, Boulegue C, Schiller HB, Ondrovičová G, Acuto O, Stockinger H, Leksa V. The late endosomal transporter CD222 directs the spatial distribution and activity of Lck. THE JOURNAL OF IMMUNOLOGY 2014; 193:2718-32. [PMID: 25127865 DOI: 10.4049/jimmunol.1303349] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The spatial and temporal organization of T cell signaling molecules is increasingly accepted as a crucial step in controlling T cell activation. CD222, also known as the cation-independent mannose 6-phosphate/insulin-like growth factor 2 receptor, is the central component of endosomal transport pathways. In this study, we show that CD222 is a key regulator of the early T cell signaling cascade. Knockdown of CD222 hampers the effective progression of TCR-induced signaling and subsequent effector functions, which can be rescued via reconstitution of CD222 expression. We decipher that Lck is retained in the cytosol of CD222-deficient cells, which obstructs the recruitment of Lck to CD45 at the cell surface, resulting in an abundant inhibitory phosphorylation signature on Lck at the steady state. Hence, CD222 specifically controls the balance between active and inactive Lck in resting T cells, which guarantees operative T cell effector functions.
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Affiliation(s)
- Karin Pfisterer
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Florian Forster
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Wolfgang Paster
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria; Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Verena Supper
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Anna Ohradanova-Repic
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Paul Eckerstorfer
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Alexander Zwirzitz
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Clemens Donner
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria
| | - Cyril Boulegue
- Department of Molecular Medicine, Max-Planck Institute of Biochemistry, Martinsried 82152, Germany; and
| | - Herbert B Schiller
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria; Department of Molecular Medicine, Max-Planck Institute of Biochemistry, Martinsried 82152, Germany; and
| | - Gabriela Ondrovičová
- Laboratory of Molecular Immunology, Institute of Molecular Biology, Slovak Academy of Sciences, 84551 Bratislava, Slovak Republic
| | - Oreste Acuto
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Hannes Stockinger
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria;
| | - Vladimir Leksa
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna A-1090, Austria; Laboratory of Molecular Immunology, Institute of Molecular Biology, Slovak Academy of Sciences, 84551 Bratislava, Slovak Republic
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Lck mediates signal transmission from CD59 to the TCR/CD3 pathway in Jurkat T cells. PLoS One 2014; 9:e85934. [PMID: 24454946 PMCID: PMC3893272 DOI: 10.1371/journal.pone.0085934] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 12/03/2013] [Indexed: 01/09/2023] Open
Abstract
The glycosylphosphatidylinositol (GPI)-anchored molecule CD59 has been implicated in the modulation of T cell responses, but the underlying molecular mechanism of CD59 influencing T cell signaling remained unclear. Here we analyzed Jurkat T cells stimulated via anti-CD3ε- or anti-CD59-coated surfaces, using time-resolved single-cell Ca2+ imaging as a read-out for stimulation. This analysis revealed a heterogeneous Ca2+ response of the cell population in a stimulus-dependent manner. Further analysis of T cell receptor (TCR)/CD3 deficient or overexpressing cells showed that CD59-mediated signaling is strongly dependent on TCR/CD3 surface expression. In protein co-patterning and fluorescence recovery after photobleaching experiments no direct physical interaction was observed between CD59 and CD3 at the plasma membrane upon anti-CD59 stimulation. However, siRNA-mediated protein knock-downs of downstream signaling molecules revealed that the Src family kinase Lck and the adaptor molecule linker of activated T cells (LAT) are essential for both signaling pathways. Furthermore, flow cytometry measurements showed that knock-down of Lck accelerates CD3 re-expression at the cell surface after anti-CD59 stimulation similar to what has been observed upon direct TCR/CD3 stimulation. Finally, physically linking Lck to CD3ζ completely abolished CD59-triggered Ca2+ signaling, while signaling was still functional upon direct TCR/CD3 stimulation. Altogether, we demonstrate that Lck mediates signal transmission from CD59 to the TCR/CD3 pathway in Jurkat T cells, and propose that CD59 may act via Lck to modulate T cell responses.
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30
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Forster F, Paster W, Supper V, Schatzlmaier P, Sunzenauer S, Ostler N, Saliba A, Eckerstorfer P, Britzen-Laurent N, Schütz G, Schmid JA, Zlabinger GJ, Naschberger E, Stürzl M, Stockinger H. Guanylate binding protein 1-mediated interaction of T cell antigen receptor signaling with the cytoskeleton. THE JOURNAL OF IMMUNOLOGY 2013; 192:771-81. [PMID: 24337748 DOI: 10.4049/jimmunol.1300377] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
GTPases act as important switches in many signaling events in cells. Although small and heterotrimeric G proteins are subjects of intensive studies, little is known about the large IFN-inducible GTPases. In this article, we show that the IFN-γ-inducible guanylate binding protein 1 (GBP-1) is a regulator of T cell activation. Silencing of GBP-1 leads to enhanced activation of early T cell Ag receptor/CD3 signaling molecules, including Lck, that is translated to higher IL-2 production. Mass spectrometry analyses showed that regulatory cytoskeletal proteins, like plastin-2 that bundles actin fibers and spectrin β-chain, brain 1 that links the plasma membrane to the actin cytoskeleton, are binding partners of GBP-1. The spectrin cytoskeleton influences cell spreading and surface expression of TCR/CD3 and the leukocyte phosphatase CD45. We found higher cell spreading and enhanced surface expression of TCR/CD3 and CD45 in GBP-1 silenced T cells that explain their enhanced TCR/CD3 signaling. We conclude that GBP-1 is a downstream processor of IFN-γ via which T cells regulate cytoskeleton-dependent cell functions.
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Affiliation(s)
- Florian Forster
- Molecular Immunology Unit, Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
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31
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Randriamampita C, Lellouch AC. Imaging early signaling events in T lymphocytes with fluorescent biosensors. Biotechnol J 2013; 9:203-12. [PMID: 24166755 DOI: 10.1002/biot.201300195] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/09/2013] [Accepted: 10/07/2013] [Indexed: 11/10/2022]
Abstract
Many recent advances in our understanding of T lymphocyte functions in adaptive immunity are derived from sophisticated imaging techniques used to visualize T lymphocyte behavior in vitro and in vivo. A current challenge is to couple such imaging techniques with methods that will allow researchers to visualize signaling phenomenon at the single-cell level. Fluorescent biosensors, either synthetic or genetically encoded, are emerging as important tools for revealing the spatio-temporal regulation of intracellular biochemical events, such as specific enzyme activities or fluctuations in metabolites. In this review, we revisit the development of fluorescent Ca(2+) sensors with which the first experiments visualizing T lymphocyte activation at the single-cell were performed, and which have since become routine tools in immunology. We then examine a number of examples of how fluorescence resonance energy transfer (FRET)-based biosensors have been developed and applied to T lymphocyte migration, adhesion and T-cell receptor (TCR)-mediated signal transduction. These include the study of small GTPases such as RhoA, Rac and Rap1, the tyrosine kinases Lck and ZAP-70, and metabolites such as cAMP and Ca(2+) . Future development and use of biosensors should allow immunologists to reconcile the vast wealth of existing biochemical data concerning T-cell functions with the power of dynamic live-cell imaging.
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Affiliation(s)
- Clotilde Randriamampita
- CNRS UMR8104, Institut Cochin, Paris, France; INSERM U567, Institut Cochin, Paris, France; Paris Descartes University, Institut Cochin, Paris, France.
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32
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Lin J, Hoppe AD. Uniform total internal reflection fluorescence illumination enables live cell fluorescence resonance energy transfer microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:350-9. [PMID: 23472941 DOI: 10.1017/s1431927612014420] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Fluorescence resonance energy transfer (FRET) microscopy is a powerful technique to quantify dynamic protein-protein interactions in live cells. Total internal reflection fluorescence (TIRF) microscopy can selectively excite molecules within about 150 nm of the glass-cell interface. Recently, these two approaches were combined to enable high-resolution FRET imaging on the adherent surface of living cells. Here, we show that interference fringing of the coherent laser excitation used in TIRF creates lateral heterogeneities that impair quantitative TIRF-FRET measurements. We overcome this limitation by using a two-dimensional scan head to rotate laser beams for donor and acceptor excitation around the back focal plane of a high numerical aperture objective. By setting different radii for the circles traced out by each laser in the back focal plane, the penetration depth was corrected for different wavelengths. These modifications quell spatial variations in illumination and permit calibration for quantitative TIRF-FRET microscopy. The capability of TIRF-FRET was demonstrated by imaging assembled cyan and yellow fluorescent protein-tagged HIV-Gag molecules in single virions on the surfaces of living cells. These interactions are shown to be distinct from crowding of HIV-Gag in lipid rafts.
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Affiliation(s)
- Jia Lin
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA
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33
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Stirnweiss A, Hartig R, Gieseler S, Lindquist JA, Reichardt P, Philipsen L, Simeoni L, Poltorak M, Merten C, Zuschratter W, Prokazov Y, Paster W, Stockinger H, Harder T, Gunzer M, Schraven B. T cell activation results in conformational changes in the Src family kinase Lck to induce its activation. Sci Signal 2013; 6:ra13. [PMID: 23423439 DOI: 10.1126/scisignal.2003607] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The lymphocyte-specific Src family protein tyrosine kinase p56(Lck) (Lck) is essential for T cell development and activation and, hence, for adaptive immune responses. The mechanism by which Lck activity is directed toward specific substrates in response to T cell receptor (TCR) activation remains elusive. We used fluorescence lifetime imaging microscopy to assess the activation-dependent spatiotemporal changes in the conformation of Lck in live human T cells. Kinetic analysis of the fluorescence lifetime of Lck biosensors enabled the direct visualization of the dynamic local opening of 20% of the total amount of Lck proteins after activation of T cells with antibody against CD3 or by superantigen-loaded antigen-presenting cells. Parallel biochemical analysis of TCR complexes revealed that the conformational changes in Lck correlated with the induction of Lck enzymatic activity. These data show the dynamic, local activation through conformational change of Lck at sites of TCR engagement.
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Affiliation(s)
- Anja Stirnweiss
- Institute of Molecular and Clinical Immunology, Otto von Guericke University, Leipziger Strasse 44, 39120 Magdeburg, Germany
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Abstract
Phosphorylation of the T cell antigen receptor (TCR) by the tyrosine kinase Lck is an essential step in the activation of T cells. Because Lck is constitutively active, spatial organization may regulate TCR signaling. Here we found that Lck distributions on the molecular level were controlled by the conformational states of Lck, with the open, active conformation inducing clustering and the closed, inactive conformation preventing clustering. In contrast, association with lipid domains and protein networks were not sufficient or necessary for Lck clustering. Conformation-driven Lck clustering was highly dynamic, so that TCR triggering resulted in Lck clusters that contained phosphorylated TCRs but excluded the phosphatase CD45. Our data suggest that Lck conformational states represent an intrinsic mechanism for the intermolecular organization of early T cell signaling.
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35
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Rossy J, Williamson DJ, Benzing C, Gaus K. The integration of signaling and the spatial organization of the T cell synapse. Front Immunol 2012. [PMID: 23189081 PMCID: PMC3504718 DOI: 10.3389/fimmu.2012.00352] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Engagement of the T cell antigen receptor (TCR) triggers signaling pathways that lead to T cell selection, differentiation and clonal expansion. Superimposed onto the biochemical network is a spatial organization that describes individual receptor molecules, dimers, oligomers and higher order structures. Here we discuss recent findings and new concepts that may regulate TCR organization in naïve and memory T cells. A key question that has emerged is how antigen-TCR interactions encode spatial information to direct T cell activation and differentiation. Single molecule super-resolution microscopy may become an important tool in decoding receptor organization at the molecular level.
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Affiliation(s)
- Jérémie Rossy
- Centre for Vascular Research and Australian Centre for Nanomedicine, University of New South Wales Sydney, NSW, Australia
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36
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Rossy J, Williamson DJ, Gaus K. How does the kinase Lck phosphorylate the T cell receptor? Spatial organization as a regulatory mechanism. Front Immunol 2012; 3:167. [PMID: 22723799 PMCID: PMC3377954 DOI: 10.3389/fimmu.2012.00167] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 06/04/2012] [Indexed: 11/25/2022] Open
Abstract
T cell signaling begins with the ligation of the T cell antigen receptor (TCR) by a cognate peptide and the phosphorylation of the receptor’s immunoreceptor tyrosine-based activation motif domains by the kinase Lck. However, the canonical receptor model is insufficient to explain how the constitutively active kinase Lck can discriminate between non-ligated and ligated TCRs. Here, we discuss the factors that are thought to regulate the spatial distribution of the TCR and Lck, and therefore critically influence TCR signaling initiation.
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Affiliation(s)
- Jérémie Rossy
- Centre for Vascular Research, University of New South Wales, Sydney, NSW, Australia
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37
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Filipp D, Ballek O, Manning J. Lck, Membrane Microdomains, and TCR Triggering Machinery: Defining the New Rules of Engagement. Front Immunol 2012; 3:155. [PMID: 22701458 PMCID: PMC3372939 DOI: 10.3389/fimmu.2012.00155] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/25/2012] [Indexed: 11/21/2022] Open
Abstract
In spite of a comprehensive understanding of the schematics of T cell receptor (TCR) signaling, the mechanisms regulating compartmentalization of signaling molecules, their transient interactions, and rearrangement of membrane structures initiated upon TCR engagement remain an outstanding problem. These gaps in our knowledge are exemplified by recent data demonstrating that TCR triggering is largely dependent on a preactivated pool of Lck concentrated in T cells in a specific type of membrane microdomains. Our current model posits that in resting T cells all critical components of TCR triggering machinery including TCR/CD3, Lck, Fyn, CD45, PAG, and LAT are associated with distinct types of lipid-based microdomains which represent the smallest structural and functional units of membrane confinement able to negatively control enzymatic activities and substrate availability that is required for the initiation of TCR signaling. In addition, the microdomains based segregation spatially limits the interaction of components of TCR triggering machinery prior to the onset of TCR signaling and allows their rapid communication and signal amplification after TCR engagement, via the process of their coalescence. Microdomains mediated compartmentalization thus represents an essential membrane organizing principle in resting T cells. The integration of these structural and functional aspects of signaling into a unified model of TCR triggering will require a deeper understanding of membrane biology, novel interdisciplinary approaches and the generation of specific reagents. We believe that the fully integrated model of TCR signaling must be based on membrane structural network which provides a proper environment for regulatory processes controlling TCR triggering.
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Affiliation(s)
- Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR Prague, Czech Republic
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38
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Nyakeriga AM, Garg H, Joshi A. TCR-induced T cell activation leads to simultaneous phosphorylation at Y505 and Y394 of p56(lck) residues. Cytometry A 2012; 81:797-805. [PMID: 22674786 DOI: 10.1002/cyto.a.22070] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 04/12/2012] [Accepted: 04/23/2012] [Indexed: 11/11/2022]
Abstract
Biochemical studies have demonstrated that phosphorylation of lymphocyte cell kinase (p56(lck) ) is crucial for activation of signaling cascades following T cell receptor (TCR) stimulation. However, whether phosphorylation/dephosphorylation of the activating or inhibitory tyrosine residues occurs upon activation is controversial. Recent advances in intracellular staining of phospho-epitopes and cytometric analysis, requiring few cells, have opened up novel avenues for the field of immunological signaling. Here, we assessed p56(lck) phosphorylation, using a multiparameter flow-cytometric based detection method following T cell stimulation. Fixation and permeabilization in conjunction with zenon labeling technology and/or fluorescently labeled antibodies against total p56(lck) or cognate phospho-tyrosine (pY) residues or surface receptors were used for detection purposes. Our observations showed that activation of Jurkat or primary human T cells using H(2) O(2) or TCR-induced stimulation led to simultaneous phosphorylation of the activating tyrosine residue, Y394 and the inhibitory tyrosine residue, Y505 of p56(lck) . This was followed by downstream calcium flux and expression of T cell activation markers; CD69 and CD40 ligand (CD40L). However, the extent of measurable activation readouts depended on the optimal stimulatory conditions (temperature and/or stimuli combinations). Treatment of cells with a p56(lck) -specific inhibitor, PP2, abolished phosphorylation at either residue in a dose-dependent manner. Taken together, these observations show that TCR-induced stimulation of T cells led to simultaneous phosphorylation of p56(lck) residues. This implies that dephosphorylation of Y505 is not crucial for p56(lck) activity. Also, it is clear that cytometric analysis provides for a rapid, sensitive, and quantitative method to supplement biochemical studies on p56(lck) signaling pathways in T cells at single cell level.
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Affiliation(s)
- Alice M Nyakeriga
- Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Drive, El Paso, Texas 79905, USA.
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Kabouridis PS, Isenberg DA, Jury EC. A negatively charged domain of LAT mediates its interaction with the active form of Lck. Mol Membr Biol 2012; 28:487-94. [PMID: 22034845 DOI: 10.3109/09687688.2011.624990] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We have shown previously that in T cells, LAT co-immunoprecipitates with the active but not the inactive-'closed' form of Lck, and that this interaction impacts negatively on Lck activity. Here we confirm that activation of T cells induced a transient LAT/Lck association within 4 min after stimulation, returning to basal levels by 30 min. Interestingly, autoimmune T cells isolated from patients with systemic lupus erythematosus, which contain a larger pool of active Lck and LAT, exhibited increased LAT/Lck association compared to healthy controls. To identify the domain of LAT responsible for its interaction with active Lck, a series of LAT truncation mutants were constructed and tested in co-immunoprecipitation experiments. We found that the segment comprising residues 112-126 of human LAT is required for its interaction with Lck. This domain is rich in negatively charged amino acids and is conserved among different species. Therefore, in addition to the conserved tyrosines, the 112-126 domain identified here could be important for certain functions of LAT in T cells.
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Affiliation(s)
- Panagiotis S Kabouridis
- William Harvey Research Institute , Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK.
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40
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Ballek O, Broučková A, Manning J, Filipp D. A specific type of membrane microdomains is involved in the maintenance and translocation of kinase active Lck to lipid rafts. Immunol Lett 2012; 142:64-74. [PMID: 22281390 DOI: 10.1016/j.imlet.2012.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 01/10/2012] [Accepted: 01/10/2012] [Indexed: 10/14/2022]
Abstract
Lck is the principal signal-generating tyrosine kinase of the T cell activation mechanism. We have previously demonstrated that induced Lck activation outside of lipid rafts (LR) results in the rapid translocation of a fraction of Lck to LR. While this translocation predicates the subsequent production of IL-2, the mechanism underpinning this process is unknown. Here, we describe the main attributes of this translocating pool of Lck. Using fractionation of Brij58 lysates, derived from primary naive non-activated CD4(+) T cells, we show that a significant portion of Lck is associated with high molecular weight complexes representing a special type of detergent-resistant membranes (DRMs) of relatively high density and sensitivity to laurylmaltoside, thus called heavy DRMs. TcR/CD4 coaggregation-mediated activation resulted in the redistribution of more than 50% of heavy DRM-associated Lck to LR in a microtubular network-dependent fashion. Remarkably, in non-activated CD4(+) T-cells, only heavy DRM-associated Lck is phosphorylated on its activatory tyrosine 394 and this pool of Lck is found to be membrane confined with CD45 phosphatase. These data are the first to illustrate a lipid microdomain-based mechanism concentrating the preactivated pool of cellular Lck and supporting its high stoichiometry of colocalization with CD45 in CD4(+) T cells. They also provide a new structural framework to assess the mechanism underpinning the compartmentalization of critical signaling elements and regulation of spatio-temporal delivery of Lck function during the T cell proximal signaling.
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Affiliation(s)
- Ondřej Ballek
- Laboratory of Immunobiology, Institute of Molecular Genetics AS CR, Prague, Czech Republic
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41
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Reneer MC, Estes DJ, Vélez-Ortega AC, Norris A, Mayer M, Marti F. Peripherally induced human regulatory T cells uncouple Kv1.3 activation from TCR-associated signaling. Eur J Immunol 2011; 41:3170-5. [PMID: 21834013 PMCID: PMC3517126 DOI: 10.1002/eji.201141492] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 06/08/2011] [Accepted: 08/08/2011] [Indexed: 11/06/2022]
Abstract
Peripherally induced Tregs (iTregs) are being recognized as a functional and physiologically relevant T-cell subset. Understanding the molecular basis of their development is a necessary step before the therapeutic potential of iTreg manipulation can be exploited. In this study, we report that the differentiation of primary human T cells to suppressor iTregs involves the relocation of key proximal TCR signaling elements to the highly active IL-2-Receptor (IL-2-R) pathway. In addition to the recruitment of lymphocyte-specific protein tyrosine kinase (Lck) to the IL-2-R complex, we identified the dissociation of the voltage-gated K(+) channel Kv1.3 from the TCR pathway and its functional coupling to the IL-2-R. The regulatory switch of Kv1.3 activity in iTregs may constitute an important contributing factor in the signaling rewiring associated with the development of peripheral human iTregs and sheds new light upon the reciprocal crosstalk between the TCR and the IL-2-R pathways.
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Affiliation(s)
- Mary Catherine Reneer
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Daniel J. Estes
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109
| | - Alejandra Catalina Vélez-Ortega
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Andrea Norris
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Michael Mayer
- Department of Biomedical Engineering and Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109
| | - Francesc Marti
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky 40536
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42
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Bamberger M, Santos AM, Gonçalves CM, Oliveira MI, James JR, Moreira A, Lozano F, Davis SJ, Carmo AM. A new pathway of CD5 glycoprotein-mediated T cell inhibition dependent on inhibitory phosphorylation of Fyn kinase. J Biol Chem 2011; 286:30324-30336. [PMID: 21757751 PMCID: PMC3162391 DOI: 10.1074/jbc.m111.230102] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Triggering of the T cell receptor initiates a signaling cascade resulting in the activation of the T cell. These signals are integrated alongside those resulting from the triggering of other receptors whose function is to modulate the overall response. CD5 is an immunotyrosine-based inhibition motif-bearing receptor that antagonizes the overt T cell receptor activation response by recruiting inhibitory intracellular mediators such as SHP-1, RasGAP, or Cbl. We now propose that the inhibitory effects of CD5 are also mediated by a parallel pathway that functions at the level of inhibition of Fyn, a kinase generally associated with T cell receptor-mediated activation. After CD5 ligation, phosphorylation of the negative regulatory tyrosine (Tyr(531)) of Fyn increases, and this correlates with a substantial reduction in the kinase activity of Fyn and a profound inhibition of ZAP-70 activation. The effect requires the last 23 amino acids of the cytoplasmic domain of the receptor, strongly implying the involvement of a new CD5-interacting signaling or adaptor protein. Furthermore, we show that upon CD5 ligation there is a profound shift in its distribution from the bulk fluid phase to the lipid raft environment, where it associates with Fyn, Lck, and PAG. We suggest that the relocation of CD5, which we also show is capable of forming homodimers, to the proximity of raft-resident molecules enables CD5 to inhibit membrane proximal signaling by controlling the phosphorylation and activity of Fyn, possibly by interfering with the disassembly of C-terminal Src kinase (Csk)-PAG-Fyn complexes during T cell activation.
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Affiliation(s)
- Martina Bamberger
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal
| | - Ana Mafalda Santos
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal
| | - Carine M Gonçalves
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal
| | - Marta I Oliveira
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal
| | - John R James
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Alexandra Moreira
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Franscisco Lozano
- Department of Immunology, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, and Department of Cell Biology, Immunology and Neurosciences, Faculty of Medicine, University of Barcelona, 08036 Barcelona, Spain
| | - Simon J Davis
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Alexandre M Carmo
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4150-180 Porto, Portugal.
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43
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Mesecke S, Urlaub D, Busch H, Eils R, Watzl C. Integration of activating and inhibitory receptor signaling by regulated phosphorylation of Vav1 in immune cells. Sci Signal 2011; 4:ra36. [PMID: 21632469 DOI: 10.1126/scisignal.2001325] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Natural killer (NK) cells are effector cells of the immune system whose activation is carefully regulated by the interplay of signals from activating and inhibitory receptors. Signals from activating receptors induce phosphorylation of the guanine nucleotide exchange factor Vav1, whereas those from inhibitory receptors lead to the dephosphorylation of Vav1 by the Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1). Here, we used mathematical modeling and experiments with NK cells to gain insight into this integration of positive and negative signals at a molecular level. Our data showed a switch-like regulation of Vav1 phosphorylation, the extent of which correlated with the cytotoxic activity of NK cells. Comparison of our experimental results with the predictions that we derived from an ensemble of 72 mathematical models showed that a physical association between Src family kinases and activating receptors on NK cells was essential to generate the cytotoxic response. Our data support a central role for Vav1 in determining the cytotoxic activity of NK cells and provide insight into the molecular mechanism of the integration of positive and negative signals during lymphocyte activation.
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Affiliation(s)
- Sven Mesecke
- Division of Theoretical Bioinformatics, German Cancer Research Center, 69120 Heidelberg, Germany
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44
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Burn GL, Svensson L, Sanchez-Blanco C, Saini M, Cope AP. Why is PTPN22 a good candidate susceptibility gene for autoimmune disease? FEBS Lett 2011; 585:3689-98. [PMID: 21515266 DOI: 10.1016/j.febslet.2011.04.032] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 04/13/2011] [Accepted: 04/13/2011] [Indexed: 10/18/2022]
Abstract
The PTPN22 locus is one of the strongest risk factors outside of the major histocompatability complex that associates with autoimmune diseases. PTPN22 encodes lymphoid protein tyrosine phosphatase (Lyp) which is expressed exclusively in immune cells. A single base change in the coding region of this gene resulting in an arginine to tryptophan amino acid substitution within a polyproline binding motif associates with type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosis, Hashimotos thyroiditis, Graves disease, Addison's disease, Myasthenia Gravis, vitiligo, systemic sclerosis juvenile idiopathic arthritis and psoriatic arthritis. Here, we review the current understanding of the PTPN22 locus from a genetic, geographical, biochemical and functional perspective.
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Affiliation(s)
- Garth L Burn
- Academic Department of Rheumatology, Division of Immunology, Infection and Inflammatory Disease, King's College School of Medicine, King's College London, UK.
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45
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Abstract
T cells use a highly complex signaling apparatus to discriminate between a diverse array of foreign antigens and a myriad of self molecules. The precise mechanism whereby signals are communicated from the antigen-binding T cell receptor to the intracellular signal transduction machinery remains a source of intense debate. This Journal Club article highlights recent research elucidating the role of the Src family kinase Lck in T cell triggering. Resting T cells contain a newly described form of preactivated Lck that is both necessary and sufficient for T cell activation but remains uncoupled from the T cell receptor in the absence of antigen. This research allows a reappraisal of the mechanisms underlying T cell triggering.
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Affiliation(s)
- Richard Berry
- Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, Faculty of Medicine, Monash University, Clayton, Victoria 3800, Australia.
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46
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Balagopalan L, Sherman E, Barr VA, Samelson LE. Imaging techniques for assaying lymphocyte activation in action. Nat Rev Immunol 2011; 11:21-33. [PMID: 21179118 PMCID: PMC3403683 DOI: 10.1038/nri2903] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Imaging techniques have greatly improved our understanding of lymphocyte activation. Technical advances in spatial and temporal resolution and new labelling tools have enabled researchers to directly observe the activation process. Consequently, research using imaging approaches to study lymphocyte activation has expanded, providing an unprecedented level of cellular and molecular detail in the field. As a result, certain models of lymphocyte activation have been verified, others have been revised and yet others have been replaced with new concepts. In this article, we review the current imaging techniques that are used to assess lymphocyte activation in different contexts, from whole animals to single molecules, and discuss the advantages and potential limitations of these methods.
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Affiliation(s)
- Lakshmi Balagopalan
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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47
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Davis SJ, van der Merwe PA. Lck and the nature of the T cell receptor trigger. Trends Immunol 2010; 32:1-5. [PMID: 21190897 DOI: 10.1016/j.it.2010.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 10/18/2010] [Accepted: 11/08/2010] [Indexed: 11/17/2022]
Abstract
Exactly how ligand binding 'triggers' T cell receptor (TCR) phosphorylation is unclear. It has been proposed that ligand engagement by the TCR somehow activates the Src kinase Lck, which in turn phosphorylates the receptor. Recent data, however, suggest instead that a significant fraction of the Lck in resting T cells is already activated and that the proportion of active Lck does not change during the early stages of T cell activation. We argue that, caveats notwithstanding, these new observations offer support for the 'kinetic-segregation' model of TCR triggering, which involves spatial reorganization of signalling proteins upon ligand binding and requires a fraction of Lck to be active in resting T cells.
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Affiliation(s)
- Simon J Davis
- Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford Radcliffe Hospital, Oxford OX3 9DS, UK.
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48
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Dong S, Corre B, Nika K, Pellegrini S, Michel F. T cell receptor signal initiation induced by low-grade stimulation requires the cooperation of LAT in human T cells. PLoS One 2010; 5:e15114. [PMID: 21152094 PMCID: PMC2994893 DOI: 10.1371/journal.pone.0015114] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 10/24/2010] [Indexed: 12/04/2022] Open
Abstract
Background One of the earliest activation events following stimulation of the T cell receptor (TCR) is the phosphorylation of the immunoreceptor tyrosine-based activation motifs (ITAMs) within the CD3-associated complex by the Src family kinase Lck. There is accumulating evidence that a large pool of Lck is constitutively active in T cells but how the TCR is connected to Lck and to the downstream signaling cascade remains elusive. Methodology/Principal Findings We have analyzed the phosphorylation state of Lck and Fyn and TCR signaling in human naïve CD4+ T cells and in the transformed T cell line, Hut-78. The latter has been shown to be similar to primary T cells in TCR-inducible phosphorylations and can be highly knocked down by RNA interference. In both T cell types, basal phosphorylation of Lck and Fyn on their activatory tyrosine was observed, although this was much less pronounced in Hut-78 cells. TCR stimulation led to the co-precipitation of Lck with the transmembrane adaptor protein LAT (linker for activation of T cells), Erk-mediated phosphorylation of Lck and no detectable dephosphorylation of Lck inhibitory tyrosine. Strikingly, upon LAT knockdown in Hut-78 cells, we found that LAT promoted TCR-induced phosphorylation of Lck and Fyn activatory tyrosines, TCRζ chain phosphorylation and Zap-70 activation. Notably, LAT regulated these events at low strength of TCR engagement. Conclusions/Significance Our results indicate for the first time that LAT promotes TCR signal initiation and suggest that this adaptor may contribute to maintain active Lck in proximity of their substrates.
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Affiliation(s)
- Shen Dong
- Unit of Cytokine Signaling, Department of Immunology, Institut Pasteur, Paris, France
- CNRS URA 1961, Paris, France
| | - Béatrice Corre
- Unit of Cytokine Signaling, Department of Immunology, Institut Pasteur, Paris, France
- CNRS URA 1961, Paris, France
| | - Konstantina Nika
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Sandra Pellegrini
- Unit of Cytokine Signaling, Department of Immunology, Institut Pasteur, Paris, France
- CNRS URA 1961, Paris, France
| | - Frédérique Michel
- Unit of Cytokine Signaling, Department of Immunology, Institut Pasteur, Paris, France
- CNRS URA 1961, Paris, France
- * E-mail:
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49
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Constitutively active Lck kinase in T cells drives antigen receptor signal transduction. Immunity 2010; 32:766-77. [PMID: 20541955 PMCID: PMC2996607 DOI: 10.1016/j.immuni.2010.05.011] [Citation(s) in RCA: 270] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 03/15/2010] [Accepted: 04/20/2010] [Indexed: 11/20/2022]
Abstract
T cell antigen receptor (TCR) and coreceptor ligation is thought to initiate signal transduction by inducing activation of the kinase Lck. Here we showed that catalytically active Lck was present in unstimulated naive T cells and thymocytes and was readily detectable in these cells in lymphoid organs. In naive T cells up to ∼40% of total Lck was constitutively activated, part of which was also phosphorylated on the C-terminal inhibitory site. Formation of activated Lck was independent of TCR and coreceptors but required Lck catalytic activity and its maintenance relied on monitoring by the HSP90-CDC37 chaperone complex to avoid degradation. The amount of activated Lck did not change after TCR and coreceptor engagement; however it determined the extent of TCR-ζ phosphorylation. Our findings suggest a dynamic regulation of Lck activity that can be promptly utilized to initiate T cell activation and have implications for signaling by other immune receptors.
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50
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Zimmermann L, Paster W, Weghuber J, Eckerstorfer P, Stockinger H, Schütz GJ. Direct observation and quantitative analysis of Lck exchange between plasma membrane and cytosol in living T cells. J Biol Chem 2010; 285:6063-70. [PMID: 20040600 PMCID: PMC2825400 DOI: 10.1074/jbc.m109.025981] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Palmitoylation represents a common motif for anchorage of cytosolic proteins to the plasma membrane. Being reversible, it allows for controlled exchange between cytosolic and plasma membrane-bound subpopulations. In this study, we present a live cell single molecule approach for quantifying the exchange kinetics of plasma membrane and cytosolic populations of fluorescently labeled Lck, the key Src family kinase involved in early T cell signaling. Total internal reflection (TIR) fluorescence microscopy was employed for confining the analysis to membrane-proximal molecules. Upon photobleaching Lck-YFP in TIR configuration, fluorescence recovery proceeds first via the cytosol outside of the evanescent field, so that in the early phase fluorescence signal arises predominantly from membrane-proximal cytosolic Lck. The diffusion constant of each molecule allowed us to distinguish whether the molecule has already associated with the plasma membrane or was still freely diffusing in the cytosol. From the number of molecules that inserted during the recovery time we quantified the insertion kinetics: on average, membrane-proximal molecules within the evanescent field needed approximately 400 ms to be inserted. The average lifetime of Lck in the plasma membrane was estimated at 50 s; together with the mobility of 0.26 microm(2)/s this provides sufficient time to explore the surface of the whole T cell before dissociation into the cytosol. Experiments on palmitoylation-deficient Lck mutants yielded similar on-rates, but substantially increased off-rates. We discuss our findings based on a model for the plasma membrane association and dissociation kinetics of Lck, which accounts for reversible palmitoylation on cysteine 3 and 5.
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Affiliation(s)
- Lars Zimmermann
- Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
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