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Kumar S, Sarkar P, Sim MJW, Rajagopalan S, Vogel SS, Long EO. A single amino acid change in inhibitory killer cell Ig-like receptor results in constitutive receptor self-association and phosphorylation. THE JOURNAL OF IMMUNOLOGY 2014; 194:817-26. [PMID: 25505289 DOI: 10.4049/jimmunol.1401830] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Signaling by immunoreceptors is often initiated by phosphorylation of cytosolic tyrosines, which then recruit effector molecules. In the case of MHC class I-specific inhibitory receptors, phosphorylation of cytosolic tyrosine residues within ITIMs results in recruitment of a protein tyrosine phosphatase that blocks activation signals. Recent work showed that signaling by an HLA-C-specific killer cell Ig-like receptor (KIR) is independent of signaling by activation receptors. It is not known how ITIM phosphorylation is initiated and regulated. In this article, we show that substitution of His-36 in the first Ig domain of KIR2DL1 with alanine (KIR2DL1-H36A) resulted in constitutive KIR2DL1 self-association and phosphorylation, as well as recruitment of tyrosine phosphatase SHP-1. Furthermore, substitution of His-36 with a similar bulky amino acid, phenylalanine, maintained the receptor in its unphosphorylated state, suggesting that steric hindrance by the His-36 side chain prevents constitutive KIR2DL1 self-association and ITIM phosphorylation. The equally strong phosphorylation of KIR2DL1 and KIR2DL1-H36A after inhibition of tyrosine phosphatase by pervanadate suggested that KIR2DL1-H36A is selectively protected from dephosphorylation. We propose that KIR phosphorylation is controlled by the accessibility of ITIM to tyrosine phosphatases and that KIR binding to HLA-C must override the hindrance that His-36 puts on KIR2DL1 self-association. Expression of KIR2DL1-H36A on NK cells led to stronger inhibition of lysis of HLA-C(+) target cells than did expression of wild-type KIR2DL1. These results revealed that ITIM phosphorylation is controlled by self-association of KIR and that His-36 serves as a gatekeeper to prevent unregulated signaling through KIR2DL1.
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Affiliation(s)
- Santosh Kumar
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Pabak Sarkar
- Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD 20892; and
| | - Malcolm J W Sim
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; Lung Immunology Group, Infectious Diseases and Immunity, Department of Medicine, Imperial College, Hammersmith Hospital, London W12 0NN, United Kingdom
| | - Sumati Rajagopalan
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Steven S Vogel
- Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD 20892; and
| | - Eric O Long
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
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52
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SHP-1-mediated inhibitory signals promote responsiveness and anti-tumour functions of natural killer cells. Nat Commun 2014; 5:5108. [PMID: 25355530 DOI: 10.1038/ncomms6108] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/28/2014] [Indexed: 11/08/2022] Open
Abstract
Natural killer (NK) cells are cytotoxic innate lymphoid cells that are involved in immune defense. NK cell reactivity is controlled in part by MHC class I recognition by inhibitory receptors, but the underlying molecular mechanisms remain undefined. Using a mouse model of conditional deletion in NK cells, we show here that the protein tyrosine phosphatase SHP-1 is essential for the inhibitory function of NK cell MHC class I receptors. In the absence of SHP-1, NK cells are hyporesponsive to tumour cells in vitro and their early Ca(2+) signals are compromised. Mice without SHP-1 in NK cells are unable to reject MHC class I-deficient transplants and to control tumours in vivo. Thus, the inhibitory activity of SHP-1 is needed for setting the threshold of NK cell reactivity.
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53
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Zhang Y, Lv G, Lou X, Peng D, Qu X, Yang X, Ayana DA, Guo H, Jiang Y. NKG2A expression and impaired function of NK cells in patients with new onset of Graves' disease. Int Immunopharmacol 2014; 24:133-9. [PMID: 25281394 DOI: 10.1016/j.intimp.2014.09.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/03/2014] [Accepted: 09/18/2014] [Indexed: 02/02/2023]
Abstract
BACKGROUND Graves' disease (GD) is an organ-specific autoimmune disease. A significant decrease of the distribution of NK cells in the peripheral blood in children and adolescents with untreated GD has been observed. However, the role of NK and its subsets in adults with GD remains unclear. METHODS A total of 28 adult patients with new onset of GD and 23 healthy controls (HC) were recruited. The number of activated inhibitory NK cells in peripheral blood of individual subjects was determined by flow cytometry. RESULTS The number of CD3(-)CD56(+) and CD3(-)CD16(+)NK cells in peripheral blood was significantly decreased in the GD patients than the HC. Compared to the HCs, decreased number of NKG2D(+), NKG2C(+), NKp30(+) and NKG2A(+) NK cells and increased number of KIR3DL1(+) NK cells were detected in the GD patients. Moreover, the number of inducible CD107a(+) and IFN-γ-secreting NK cells in GD patients significantly decreased than those in HC. Interestingly, the number of NKG2A(+)NK cells was negatively correlated with the level of serum TRAb in GD patients. CONCLUSION Our data indicate that decreased number and impaired function of NK cells may contribute to the pathogenesis of GD.
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Affiliation(s)
- Yupan Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China.
| | - Guoyue Lv
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China.
| | - Xiaoqian Lou
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China.
| | - Di Peng
- Department of Endocrinology, Center Hospital of Tonghua City, Tonghua 134000, China.
| | - Xiaozhang Qu
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China.
| | - Xige Yang
- Department of Anesthesiology, The First Hospital, Jilin University, Changchun 130021, China.
| | | | - Hui Guo
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China.
| | - Yanfang Jiang
- Key Laboratory of Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun 130021, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
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54
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Celis-Gutierrez J, Boyron M, Walzer T, Pandolfi PP, Jonjić S, Olive D, Dalod M, Vivier E, Nunès JA. Dok1 and Dok2 proteins regulate natural killer cell development and function. EMBO J 2014; 33:1928-40. [PMID: 24963146 DOI: 10.15252/embj.201387404] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Natural killer (NK) cells are involved in immune responses against tumors and microbes. NK-cell activation is regulated by intrinsic and extrinsic mechanisms that ensure NK tolerance and efficacy. Here, we show that the cytoplasmic signaling molecules Dok1 and Dok2 are tyrosine phosphorylated upon NK-cell activation. Overexpression of Dok proteins in human NK cells reduces cell activation induced by NK-cell-activating receptors. Dok1 and Dok2 gene ablation in mice induces an NK-cell maturation defect and leads to increased IFN-γ production induced by activating receptors. Taken together, these results reveal that Dok1 and Dok2 proteins are involved in an intrinsic negative feedback loop downstream of NK-cell-activating receptors in mouse and human.
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Affiliation(s)
- Javier Celis-Gutierrez
- INSERM U1068 Centre de Recherche en Cancérologie de Marseille, Marseille, France Institut Paoli-Calmettes, Marseille, France CNRS UMR7258 Centre de Recherche en Cancérologie de Marseille, Marseille, France Aix-Marseille Université, Marseille, France
| | - Marilyn Boyron
- Aix-Marseille Université, Marseille, France Centre d'Immunologie de Marseille-Luminy INSERM U1104, Marseille, France CNRS UMR7280, Marseille, France
| | - Thierry Walzer
- Aix-Marseille Université, Marseille, France Centre d'Immunologie de Marseille-Luminy INSERM U1104, Marseille, France CNRS UMR7280, Marseille, France Université de Lyon INSERM U1111, Lyon, France
| | - Pier Paolo Pandolfi
- Departments of Medicine and Pathology, Cancer Genetics Program, Beth Israel Deaconess Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Stipan Jonjić
- Department for Histology and Embryology, School of Medicine University of Rijeka, Rijeka, Croatia
| | - Daniel Olive
- INSERM U1068 Centre de Recherche en Cancérologie de Marseille, Marseille, France Institut Paoli-Calmettes, Marseille, France CNRS UMR7258 Centre de Recherche en Cancérologie de Marseille, Marseille, France Aix-Marseille Université, Marseille, France
| | - Marc Dalod
- Aix-Marseille Université, Marseille, France Centre d'Immunologie de Marseille-Luminy INSERM U1104, Marseille, France CNRS UMR7280, Marseille, France
| | - Eric Vivier
- Aix-Marseille Université, Marseille, France Centre d'Immunologie de Marseille-Luminy INSERM U1104, Marseille, France CNRS UMR7280, Marseille, France Service d'Immunologie, Assistance Publique - Hôpitaux de Marseille Hôpital de la Conception, Marseille, France
| | - Jacques A Nunès
- INSERM U1068 Centre de Recherche en Cancérologie de Marseille, Marseille, France Institut Paoli-Calmettes, Marseille, France CNRS UMR7258 Centre de Recherche en Cancérologie de Marseille, Marseille, France Aix-Marseille Université, Marseille, France
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Lagrue K, Carisey A, Oszmiana A, Kennedy PR, Williamson DJ, Cartwright A, Barthen C, Davis DM. The central role of the cytoskeleton in mechanisms and functions of the NK cell immune synapse. Immunol Rev 2014; 256:203-21. [PMID: 24117823 DOI: 10.1111/imr.12107] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Natural killer (NK) cells discriminate between healthy and unhealthy target cells through a balance of activating and inhibitory signals at direct intercellular contacts called immune synapses. Rearrangements in the cellular cytoskeleton have long been known to be critical in assembly of immune synapses. Here, through bringing together the vast literature on this subject, the number of different ways in which the cytoskeleton is important becomes evident. The dynamics of filamentous actin are critical in (i) creating the nanometer-scale organization of NK cell receptors, (ii) establishing cellular polarity, (iii) coordinating immune receptor and integrin-mediated signaling, and (iv) directing secretion of lytic granules and cytokines. The microtubule network also is important in the delivery of lytic granules and vesicles containing cytokines to the immune synapse. Together, these data establish that the cytoskeleton acts as a central regulator of this complex and dynamic process - and an enormous amount of NK cell biology is controlled through the cytoskeleton.
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Affiliation(s)
- Kathryn Lagrue
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, UK; Division of Cell and Molecular Biology, Imperial College, London, UK
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56
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Nash WT, Teoh J, Wei H, Gamache A, Brown MG. Know Thyself: NK-Cell Inhibitory Receptors Prompt Self-Tolerance, Education, and Viral Control. Front Immunol 2014; 5:175. [PMID: 24795719 PMCID: PMC3997006 DOI: 10.3389/fimmu.2014.00175] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/03/2014] [Indexed: 01/05/2023] Open
Abstract
Natural killer (NK) cells provide essential protection against viral infections. One of the defining features of this lymphocyte population is the expression of a wide array of variable cell surface stimulatory and inhibitory NK receptors (sNKR and iNKR, respectively). The iNKR are particularly important in terms of NK-cell education. As receptors specific for MHC class I (MHC I) molecules, they are responsible for self-tolerance and adjusting NK-cell reactivity based on the expression level of self-MHC I. The end result of this education is twofold: (1) inhibitory signaling tunes the functional capacity of the NK cell, endowing greater potency with greater education, and (2) education on self allows the NK cell to detect aberrations in MHC I expression, a common occurrence during many viral infections. Many studies have indicated an important role for iNKR and MHC I in disease, making these receptors attractive targets for manipulating NK-cell reactivity in the clinic. A greater understanding of iNKR and their ability to regulate NK cells will provide a basis for future attempts at translating their potential utility into benefits for human health.
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Affiliation(s)
- William T Nash
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Jeffrey Teoh
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Hairong Wei
- Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Division of Nephrology, Department of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Awndre Gamache
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA
| | - Michael G Brown
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Beirne B. Carter Center for Immunology Research, School of Medicine, University of Virginia , Charlottesville, VA , USA ; Division of Nephrology, Department of Medicine, University of Virginia , Charlottesville, VA , USA
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57
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Nieto-Pelegrin E, Meiler E, Martín-Villa JM, Benito-León M, Martinez-Quiles N. Crk adaptors negatively regulate actin polymerization in pedestals formed by enteropathogenic Escherichia coli (EPEC) by binding to Tir effector. PLoS Pathog 2014; 10:e1004022. [PMID: 24675776 PMCID: PMC3968158 DOI: 10.1371/journal.ppat.1004022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 02/05/2014] [Indexed: 01/04/2023] Open
Abstract
Infections by enteropathogenic Escherichia coli (EPEC) cause diarrhea linked to high infant mortality in developing countries. EPEC adheres to epithelial cells and induces the formation of actin pedestals. Actin polymerization is driven fundamentally through signaling mediated by Tir bacterial effector protein, which inserts in the plasma membrane of the infected cell. Tir binds Nck adaptor proteins, which in turn recruit and activate N-WASP, a ubiquitous member of the Wiskott-Aldrich syndrome family of proteins. N-WASP activates the Arp2/3 complex to promote actin polymerization. Other proteins aside from components of the Tir-Nck-N-WASP pathway are recruited to the pedestals but their functions are unknown. Here we investigate the function of two alternatively spliced isoforms of Crk adaptors (CrkI/II) and the paralog protein CrkL during pedestal formation by EPEC. We found that the Crk isoforms act as redundant inhibitors of pedestal formation. The SH2 domain of CrkII and CrkL binds to phosphorylated tyrosine 474 of Tir and competes with Nck to bind Tir, preventing its recruitment to pedestals and thereby inhibiting actin polymerization. EPEC infection induces phosphorylation of the major regulatory tyrosine in CrkII and CrkL, possibly preventing the SH2 domain of these proteins from interacting with Tir. Phosphorylated CrkII and CrkL proteins localize specifically to the plasma membrane in contact with EPEC. Our study uncovers a novel role for Crk adaptors at pedestals, opening a new perspective in how these oncoproteins regulate actin polymerization.
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Affiliation(s)
- Elvira Nieto-Pelegrin
- Department of Microbiology, School of Pharmacy, Complutense University, Madrid, Spain
| | - Eugenia Meiler
- Division of Immunology, School of Medicine, Complutense University, Madrid, Spain
| | | | - María Benito-León
- Division of Immunology, School of Medicine, Complutense University, Madrid, Spain
| | - Narcisa Martinez-Quiles
- Department of Microbiology, School of Pharmacy, Complutense University, Madrid, Spain
- Division of Immunology, School of Medicine, Complutense University, Madrid, Spain
- * E-mail:
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58
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Mace EM, Dongre P, Hsu HT, Sinha P, James AM, Mann SS, Forbes LR, Watkin LB, Orange JS. Cell biological steps and checkpoints in accessing NK cell cytotoxicity. Immunol Cell Biol 2014; 92:245-55. [PMID: 24445602 PMCID: PMC3960583 DOI: 10.1038/icb.2013.96] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 11/06/2013] [Indexed: 12/11/2022]
Abstract
Natural killer (NK) cell-mediated cytotoxicity is governed by the formation of a lytic immune synapse in discrete regulated steps, which give rise to an extensive array of cellular checkpoints in accessing NK cell-mediated cytolytic defense. Appropriate progression through these cell biological steps is critical for the directed secretion of specialized secretory lysosomes and subsequent target cell death. Here we highlight recent discoveries in the formation of the NK cell cytolytic synapse as well as the molecular steps and cell biological checkpoints required for this essential host defense process.
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Affiliation(s)
- Emily M Mace
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Prachi Dongre
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Hsiang-Ting Hsu
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Papiya Sinha
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | | | - Shaina S Mann
- Case Western Reserve Medical School, Cleveland, OH, USA
| | - Lisa R Forbes
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Levi B Watkin
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Jordan S Orange
- Center for Human Immunobiology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
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59
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Abstract
The functions of Natural Killer (NK) cells are regulated by a highly redundant set of germline-encoded surface receptors that can inhibit or activate NK cell activities. NK cells can be activated by cytokines or through the interaction with transformed or infected cells. This typically results in the production of cytokines, chemokines, and the induction of cellular cytotoxicity. However, the reactivity of NK cells is modulated on various levels and shaped by processes such as development, education, priming, exposure to antigens and cytokines, and the formation of memory-like phenotypes. Here, I will summarize our current understanding of these processes and describe how they influence NK cell reactivity on a molecular level.
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Affiliation(s)
- Carsten Watzl
- Leibniz Research Center for Working Environment and Human Factors, IfADo, Dortmund, Germany.
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60
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Abeyweera TP, Kaissar M, Huse M. Inhibitory receptor signaling destabilizes immunological synapse formation in primary NK cells. Front Immunol 2013; 4:410. [PMID: 24348477 PMCID: PMC3841721 DOI: 10.3389/fimmu.2013.00410] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/11/2013] [Indexed: 01/24/2023] Open
Abstract
Upon engagement of their cognate class I major histocompatibility complex ligands, receptors containing immunotyrosine-based inhibitory motifs (ITIMs) transduce signals that block cytolytic and inflammatory responses. In this manner, ITIM-coupled receptors play a crucial role in maintaining natural killer (NK) cell tolerance toward normal, healthy tissue. A number of studies, mostly using immortalized NK cell lines, have demonstrated that ITIM signaling functions by disrupting the cytolytic immunological synapse formed between an NK cell and its target. However, more recent imaging experiments using primary NK cells have suggested that inhibitory receptor engagement does not antagonize contact formation, casting doubt on the hypothesis that ITIM signals destabilize the synapse. To resolve this issue, we analyzed primary NK cell activation and contact formation on supported lipid bilayers containing controlled combinations of activating and inhibitory ligands. Under these conditions, we observed that ITIM signaling clearly inhibited adhesion, cell arrest, and calcium influx, three hallmarks of synapse formation. These results are consistent with previous reports showing that inhibitory receptors deliver a “reverse stop” signal, and confirm that ITIM signaling functions at least in part by destabilizing cytolytic synapse formation.
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Affiliation(s)
| | - Molly Kaissar
- Immunology Program, Memorial Sloan-Kettering Cancer Center , New York, NY , USA
| | - Morgan Huse
- Immunology Program, Memorial Sloan-Kettering Cancer Center , New York, NY , USA
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Galandrini R, Capuano C, Santoni A. Activation of Lymphocyte Cytolytic Machinery: Where are We? Front Immunol 2013; 4:390. [PMID: 24312097 PMCID: PMC3832890 DOI: 10.3389/fimmu.2013.00390] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/06/2013] [Indexed: 11/13/2022] Open
Abstract
Target cell recognition by cytotoxic lymphocytes implies the simultaneous engagement and clustering of adhesion and activating receptors followed by the activation of an array of signal transduction pathways. The cytotoxic immune synapse represents the highly specialized dynamic interface formed between the cytolytic effector and its target that allows temporal and spatial integration of signals responsible for a defined sequence of processes culminating with the polarized secretion of lytic granules. Over the last decades, much attention has been given to the molecular signals coupling receptor ligation to the activation of cytolytic machinery. Moreover, in the last 10 years the discovery of genetic defects affecting cytotoxic responses greatly boosted our knowledge on the molecular effectors involved in the regulation of discrete phases of cytotoxic process at post-receptor levels. More recently, the use of super resolution and total internal reflection fluorescence imaging technologies added new insights on the dynamic reorganization of receptor and signaling molecules at lytic synapse as well as on the relationship between granule dynamics and cytoskeleton remodeling. To date we have a solid knowledge of the molecular mechanisms governing granule movement and secretion, being not yet fully unraveled the machinery that couples early receptor signaling to the late stage of synapse remodeling and granule dynamics. Here we highlight recent advances in our understanding of the molecular mechanisms acting in the activation of cytolytic machinery, also discussing similarities and differences between Natural killer cells and cytotoxic CD8+ T cells.
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Affiliation(s)
- Ricciarda Galandrini
- Department of Experimental Medicine, Istituto Pasteur-Fondazione Cenci-Bolognetti, Fondazione Eleonora Lorillard Spencer Cenci, Sapienza University , Rome , Italy
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62
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The adaptor protein Crk in immune response. Immunol Cell Biol 2013; 92:80-9. [PMID: 24165979 DOI: 10.1038/icb.2013.64] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 09/02/2013] [Accepted: 09/23/2013] [Indexed: 12/17/2022]
Abstract
The adaptor proteins Crk (CT10 (chicken tumor virus number 10) regulator of kinase), including CrkI, CrkII and Crk-like, are important signal molecules that regulate a variety of cellular processes. Considerable progress has been made in understanding the roles of the Crk family proteins in signal transduction, with a focus on cellular transformation and differentiation. However, since Crk was identified in 1988, very few studies have addressed how Crk regulates the immune response. Recent work demonstrates that Crk proteins function as critical signal molecules in regulating immune cell functions. Emerging data on the roles of Crk in activation and inhibitory immunoreceptor signaling suggest that Crk proteins are potential immunotherapeutic targets in cancer and infectious diseases. The aim of this review is to summarize recent key findings regarding the role of Crk in immune responses mediated by T, B and natural killer (NK) cells. In particular, the roles of Crk in NK cell functions are discussed.
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63
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Pageon SV, Cordoba SP, Owen DM, Rothery SM, Oszmiana A, Davis DM. Superresolution microscopy reveals nanometer-scale reorganization of inhibitory natural killer cell receptors upon activation of NKG2D. Sci Signal 2013; 6:ra62. [PMID: 23882121 DOI: 10.1126/scisignal.2003947] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Natural killer (NK) cell responses are regulated by a dynamic equilibrium between activating and inhibitory receptor signals at the immune synapse (or interface) with target cells. Although the organization of receptors at the immune synapse is important for appropriate integration of these signals, there is little understanding of this in detail, because research has been hampered by the limited resolution of light microscopy. Through the use of superresolution single-molecule fluorescence microscopy to reveal the organization of the NK cell surface at the single-protein level, we report that the inhibitory receptor KIR2DL1 is organized in nanometer-scale clusters at the surface of human resting NK cells. Nanoclusters of KIR2DL1 became smaller and denser upon engagement of the activating receptor NKG2D, establishing an unexpected crosstalk between activating receptor signals and the positioning of inhibitory receptors. These rearrangements in the nanoscale organization of surface NK cell receptors were dependent on the actin cytoskeleton. Together, these data establish that NK cell activation involves a nanometer-scale reorganization of surface receptors, which in turn affects models for signal integration and thresholds that control NK cell effector functions and NK cell development.
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Affiliation(s)
- Sophie V Pageon
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, UK
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Huse M, Catherine Milanoski S, Abeyweera TP. Building tolerance by dismantling synapses: inhibitory receptor signaling in natural killer cells. Immunol Rev 2013; 251:143-53. [PMID: 23278746 DOI: 10.1111/imr.12014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cell surface receptors bearing immunotyrosine-based inhibitory motifs (ITIMs) maintain natural killer (NK) cell tolerance to normal host tissues. These receptors are difficult to analyze mechanistically because they block activating responses in a rapid and comprehensive manner. The advent of high-resolution single cell imaging techniques has enabled investigators to explore the cell biological basis of the inhibitory response. Recent studies using these approaches indicate that ITIM-containing receptors function at least in part by structurally undermining the immunological synapse between the NK cell and its target. In this review, we discuss these new advances and how they might relate to what is known about the biochemistry of inhibitory signaling in NK cells and other cell types.
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Affiliation(s)
- Morgan Huse
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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65
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Super-resolution microscopy of the immunological synapse. Curr Opin Immunol 2013; 25:307-12. [PMID: 23746999 DOI: 10.1016/j.coi.2013.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/12/2013] [Accepted: 04/15/2013] [Indexed: 12/18/2022]
Abstract
Deciphering the spatial organisation of signalling proteins is the key to understanding the mechanisms underlying immune cell activation. Every advance in imaging technology has led to major breakthroughs in unravelling how receptor and signalling proteins are distributed within the plasma membrane and how membrane signalling is integrated with endosomes and vesicular trafficking. Recently, super-resolution fluorescence microscopy has been applied to immunological synapses, gaining new insights into the nanoscale organisation of signalling processes. Here, we review the advantages and potential of super-resolution microscopy for elucidating the regulation of many aspects of immune signalling.
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Delcassian D, Depoil D, Rudnicka D, Liu M, Davis DM, Dustin ML, Dunlop IE. Nanoscale ligand spacing influences receptor triggering in T cells and NK cells. NANO LETTERS 2013; 13:5608-14. [PMID: 24125583 PMCID: PMC4288448 DOI: 10.1021/nl403252x] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Bioactive nanoscale arrays were constructed to ligate activating cell surface receptors on T cells (the CD3 component of the TCR complex) and natural killer (NK) cells (CD16). These arrays are formed from biofunctionalized gold nanospheres with controlled interparticle spacing in the range 25-104 nm. Responses to these nanoarrays were assessed using the extent of membrane-localized phosphotyrosine in T cells stimulated with CD3-binding nanoarrays and the size of cell contact area for NK cells stimulated with CD16-binding nanoarrays. In both cases, the strength of response decreased with increasing spacing, falling to background levels by 69 nm in the T cell/anti-CD3 system and 104 nm for the NK cell/anti-CD16 system. These results demonstrate that immune receptor triggering can be influenced by the nanoscale spatial organization of receptor/ligand interactions.
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MESH Headings
- CD3 Complex/chemistry
- CD3 Complex/immunology
- Humans
- Killer Cells, Natural/chemistry
- Killer Cells, Natural/immunology
- Nanoparticles/chemistry
- Nanotechnology
- Receptor-CD3 Complex, Antigen, T-Cell/chemistry
- Receptor-CD3 Complex, Antigen, T-Cell/immunology
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/immunology
- Receptors, IgG/chemistry
- Receptors, IgG/immunology
- Receptors, Natural Killer Cell/chemistry
- Receptors, Natural Killer Cell/immunology
- T-Lymphocytes/chemistry
- T-Lymphocytes/immunology
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Affiliation(s)
- Derfogail Delcassian
- Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - David Depoil
- Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, New York, NY10016 USA
| | - Dominika Rudnicka
- Division of Cell and Molecular Biology, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Mengling Liu
- Department of Biostatistics, NYU School of Medicine, New York, New York, NY10016 USA
| | - Daniel M. Davis
- Division of Cell and Molecular Biology, Imperial College London, Exhibition Road, London SW7 2AZ, UK
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Grafton Street, Manchester M13 9NT, UK
| | - Michael L. Dustin
- Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, New York, NY10016 USA
- Kennedy Institute of Rheumatology, University of Oxford, Old Road Campus, Oxford, OX3 7FY, UK
| | - Iain E. Dunlop
- Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, UK
- To whom correspondence should be addressed:
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Long EO, Kim HS, Liu D, Peterson ME, Rajagopalan S. Controlling natural killer cell responses: integration of signals for activation and inhibition. Annu Rev Immunol 2013; 31:227-58. [PMID: 23516982 PMCID: PMC3868343 DOI: 10.1146/annurev-immunol-020711-075005] [Citation(s) in RCA: 879] [Impact Index Per Article: 79.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Understanding how signals are integrated to control natural killer (NK) cell responsiveness in the absence of antigen-specific receptors has been a challenge, but recent work has revealed some underlying principles that govern NK cell responses. NK cells use an array of innate receptors to sense their environment and respond to alterations caused by infections, cellular stress, and transformation. No single activation receptor dominates; instead, synergistic signals from combinations of receptors are integrated to activate natural cytotoxicity and cytokine production. Inhibitory receptors for major histocompatibility complex class I (MHC-I) have a critical role in controlling NK cell responses and, paradoxically, in maintaining NK cells in a state of responsiveness to subsequent activation events, a process referred to as licensing. MHC-I-specific inhibitory receptors both block activation signals and trigger signals to phosphorylate and inactivate the small adaptor Crk. These different facets of inhibitory signaling are incorporated into a revocable license model for the reversible tuning of NK cell responsiveness.
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Affiliation(s)
- Eric O. Long
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852
| | - Hun Sik Kim
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852
- Department of Medicine, Graduate School, University of Ulsan, Seoul 138-736, Korea;
| | - Dongfang Liu
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852
- Center for Human Immunobiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77030;
| | - Mary E. Peterson
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852
| | - Sumati Rajagopalan
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852
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Pageon SV, Rudnicka D, Davis DM. Illuminating the dynamics of signal integration in Natural Killer cells. Front Immunol 2012; 3:308. [PMID: 23060886 PMCID: PMC3463929 DOI: 10.3389/fimmu.2012.00308] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 09/17/2012] [Indexed: 11/13/2022] Open
Abstract
Natural Killer (NK) cell responses are shaped by the integration of signals transduced from multiple activating and inhibitory receptors at their surface. Biochemical and genetic approaches have identified most of the key proteins involved in signal integration but a major challenge remains in understanding how the spatial and temporal dynamics of their interactions lead to NK cells responding appropriately when encountering ligands on target cells. Well over a decade of research using fluorescence microscopy has revealed much about the architecture of the NK cell immune synapse - the structured interface between NK cells and target cells - and how it varies when inhibition or activation is the outcome of signal integration. However, key questions - such as the proximity of individual activating and inhibitory receptors - have remained unanswered because the resolution of optical microscopy has been insufficient, being limited by diffraction. Recent developments in fluorescence microscopy have broken this limit, seeding new opportunities for studying the nanometer-scale organization of the NK cell immune synapse. Here, we discuss how these new technologies, super-resolution imaging and other novel light-based methods, can illuminate our understanding of NK cell biology.
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Affiliation(s)
- Sophie V Pageon
- Division of Cell and Molecular Biology, Imperial College London London, UK
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69
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Super-resolution imaging of remodeled synaptic actin reveals different synergies between NK cell receptors and integrins. Blood 2012; 120:3729-40. [PMID: 22966166 DOI: 10.1182/blood-2012-05-429977] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Natural killer (NK) cells secrete lytic granules to directly kill virus-infected or transformed cells and secrete cytokines to communicate with other cells. Three-dimensional super-resolved images of F-actin, lytic granules, and IFN-γ in primary human NK cells stimulated through different activating receptors reveal that both IFN-γ and lytic granules accumulated in domains where the periodicity of the cortical actin mesh at the synapse opened up to be penetrable. Ligation of some activating receptors alone (eg, CD16 or NKG2D) was sufficient to increase the periodicity of the actin mesh, but surprisingly, ligation of others (eg, NKp46 or CD2) was not sufficient to induce cortical actin remodeling unless LFA-1 was coligated. Importantly, influenza virus particles that can be recognized by NK cells similarly did not open the actin mesh but could if LFA-1 was coligated. This leads us to propose that immune cells using germline-encoded receptors to directly recognize foreign proteins can use integrin recognition to differentiate between free pathogens and pathogen-infected cells that will both be present in blood. This distinction would not be required for NK cell receptors, such as NKG2D, which recognize host cell-encoded proteins that can only be found on diseased cells and not pathogens.
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Kumari S, Vardhana S, Cammer M, Curado S, Santos L, Sheetz MP, Dustin ML. T Lymphocyte Myosin IIA is Required for Maturation of the Immunological Synapse. Front Immunol 2012; 3:230. [PMID: 22912631 PMCID: PMC3421155 DOI: 10.3389/fimmu.2012.00230] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 07/14/2012] [Indexed: 01/13/2023] Open
Abstract
The role of non-muscle myosin IIA (heavy chain encoded by the non-muscle myosin heavy chain 9 gene, Myh9) in immunological synapse formation is controversial. We have addressed the role of myosin IIA heavy chain protein (MYH9) in mouse T cells responding to MHC-peptide complexes and ICAM-1 in supported planar bilayers - a model for immunological synapse maturation. We found that reduction of MYH9 expression levels using Myh9 siRNA in proliferating mouse CD4(+) AND T cell receptor (TCR) transgenic T cells resulted in increased spreading area, failure to assemble the central and peripheral supramolecular activation clusters (cSMAC and pSMAC), and increased motility. Surprisingly, TCR microcluster speed was reduced marginally, however TCR microclusters dissipated prior to forming a cSMAC. TCR microclusters formed in the Myh9 siRNA-treated T cells showed reduced phosphorylation of the Src family kinase (SFK) activation loop and displayed reduced cytoplasmic calcium ion (Ca(2+)) elevation. In addition, Myh9 siRNA-treated cells displayed reduced phosphorylation of the Cas-L substrate domain - a force-dependent SFK substrate - which was observed in control siRNA-treated cells in foci throughout the immunological synapse except the cSMAC. Cas-L exhibited TCR ligation-dependent induction of phosphorylation. These results provide further evidence that T cell activation is modulated by intrinsic force-generating systems and can be viewed as a mechanically responsive process influenced by MYH9.
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Affiliation(s)
- Sudha Kumari
- Helen and Martin Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew York, NY, USA
| | - Santosha Vardhana
- Helen and Martin Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew York, NY, USA
| | - Michael Cammer
- Helen and Martin Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew York, NY, USA
| | - Silvia Curado
- Helen and Martin Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew York, NY, USA
| | - Luis Santos
- Department of Biological Sciences, Columbia UniversityNew York, NY, USA
| | - Michael P. Sheetz
- Department of Biological Sciences, Columbia UniversityNew York, NY, USA
| | - Michael L. Dustin
- Helen and Martin Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of MedicineNew York, NY, USA
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