1
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Barton MI, Paterson RL, Denham EM, Goyette J, van der Merwe PA. Ligand requirements for immunoreceptor triggering. Commun Biol 2024; 7:1138. [PMID: 39271744 PMCID: PMC11399299 DOI: 10.1038/s42003-024-06817-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 08/30/2024] [Indexed: 09/15/2024] Open
Abstract
Leukocytes interact with other cells using cell surface receptors. The largest group of such receptors are non-catalytic tyrosine phosphorylated receptors (NTRs), also called immunoreceptors. NTR signalling requires phosphorylation of cytoplasmic tyrosine residues by SRC-family tyrosine kinases. How ligand binding to NTRs induces this phosphorylation, also called NTR triggering, remains controversial, with roles suggested for size-based segregation, clustering, and mechanical force. Here we exploit a recently developed cell-surface generic ligand system to explore the ligand requirements for NTR triggering. We examine the effect of varying the ligand's length, mobility and valency on the activation of representative members of four NTR families: SIRPβ1, Siglec 14, NKp44 and TREM-1. Increasing the ligand length impairs activation via NTRs, despite enhancing cell-cell conjugation, while varying ligand mobility has little effect on either conjugation or activation. Increasing the valency of the ligand, while enhancing cell-cell conjugation, does not enhance activation at equivalent levels of conjugation. These findings are more consistent with a role for size-based segregation, rather than mechanical force or clustering, in NTR triggering, suggesting a role for the kinetic-segregation model.
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Affiliation(s)
- Michael I Barton
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rachel L Paterson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, Parque de Ciência e Tecnologia Avepark, Zona Industrial da Gandra, Barco, Portugal
| | - Eleanor M Denham
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Enara Bio, The Magdalen Centre, Oxford Science Park, 1 Robert Robinson Avenue, Oxford, UK
| | - Jesse Goyette
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Department of Molecular Medicine, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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2
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Worboys JD, Davis DM. Do inhibitory receptors need to be proximal to stimulatory receptors to function? Genes Immun 2024; 25:343-345. [PMID: 38216665 PMCID: PMC11327099 DOI: 10.1038/s41435-023-00251-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/14/2024]
Affiliation(s)
- Jonathan D Worboys
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Daniel M Davis
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, South Kensington, London, UK.
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3
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Partin AC, Bruno R, Shafaattalab S, Vander Mause E, Winters A, Daris M, Gahrs C, Jette CA, DiAndreth B, Sandberg ML, Hamburger AE, Kamb A, Riley TP. Geometric parameters that affect the behavior of logic-gated CAR T cells. Front Immunol 2024; 15:1304765. [PMID: 38343543 PMCID: PMC10853413 DOI: 10.3389/fimmu.2024.1304765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
Clinical applications of CAR-T cells are limited by the scarcity of tumor-specific targets and are often afflicted with the same on-target/off-tumor toxicities that plague other cancer treatments. A new promising strategy to enforce tumor selectivity is the use of logic-gated, two-receptor systems. One well-described application is termed Tmod™, which originally utilized a blocking inhibitory receptor directed towards HLA-I target antigens to create a protective NOT gate. Here we show that the function of Tmod blockers targeting non-HLA-I antigens is dependent on the height of the blocker antigen and is generally compatible with small, membrane-proximal targets. We compensate for this apparent limitation by incorporating modular hinge units to artificially extend or retract the ligand-binding domains relative to the effector cell surface, thereby modulating Tmod activator and blocker function. By accounting for structural differences between activator and blocker targets, we developed a set of simple geometric parameters for Tmod receptor design that enables targeting of blocker antigens beyond HLA-I, thereby broadening the applications of logic-gated cell therapies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Alexander Kamb
- A2 Biotherapeutics, Inc., Agoura Hills, CA, United States
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4
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Tomaz D, Pereira PM, Guerra N, Dyson J, Gould K, Henriques R. Nanoscale Colocalization of NK Cell Activating and Inhibitory Receptors Controls Signal Integration. Front Immunol 2022; 13:868496. [PMID: 35720315 PMCID: PMC9198454 DOI: 10.3389/fimmu.2022.868496] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
Natural killer (NK) cell responses depend on the balance of signals from inhibitory and activating receptors. However, how the integration of antagonistic signals occurs upon NK cell-target cell interaction is not fully understood. Here we provide evidence that NK cell inhibition via the inhibitory receptor Ly49A is dependent on its relative colocalization at the nanometer scale with the activating receptor NKG2D upon immune synapse (IS) formation. NKG2D and Ly49A signal integration and colocalization were studied using NKG2D-GFP and Ly49A-RFP-expressing primary NK cells, forming ISs with NIH3T3 target cells, with or without the expression of single-chain trimer (SCT) H2-Dd and an extended form of SCT H2-Dd-CD4 MHC-I molecules. Nanoscale colocalization was assessed by Förster resonance energy transfer between NKG2D-GFP and Ly49A-RFP and measured for each synapse. In the presence of their respective cognate ligands, NKG2D and Ly49A colocalize at the nanometer scale, leading to NK cell inhibition. However, increasing the size of the Ly49A ligand reduced the nanoscale colocalization with NKG2D, consequently impairing Ly49A-mediated inhibition. Thus, our data shows that NK cell signal integration is critically dependent on the dimensions of NK cell ligand-receptor pairs by affecting their relative nanometer-scale colocalization at the IS. Our results together suggest that the balance of NK cell signals and NK cell responses is determined by the relative nanoscale colocalization of activating and inhibitory receptors in the immune synapse.
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Affiliation(s)
- David Tomaz
- Department of Immunology, Wright-Fleming Institute, Imperial College London, London, United Kingdom
- Department of Immunology, Hammersmith Hospital, Imperial College London, London, United Kingdom
| | - Pedro Matos Pereira
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Nadia Guerra
- Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Julian Dyson
- Department of Immunology, Hammersmith Hospital, Imperial College London, London, United Kingdom
| | - Keith Gould
- Department of Immunology, Wright-Fleming Institute, Imperial College London, London, United Kingdom
| | - Ricardo Henriques
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Division of Infection and Immunity, University College London, London, United Kingdom
- Optical Cell Biology Lab, Instituto Gulbenkian de Ciência, Oeiras, Portugal
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5
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Grewal RK, Das J. Spatially resolved in silico modeling of NKG2D signaling kinetics suggests a key role of NKG2D and Vav1 Co-clustering in generating natural killer cell activation. PLoS Comput Biol 2022; 18:e1010114. [PMID: 35584138 PMCID: PMC9154193 DOI: 10.1371/journal.pcbi.1010114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 05/31/2022] [Accepted: 04/18/2022] [Indexed: 11/18/2022] Open
Abstract
Natural Killer (NK) cells provide key resistance against viral infections and tumors. A diverse set of activating and inhibitory NK cell receptors (NKRs) interact with cognate ligands presented by target host cells, where integration of dueling signals initiated by the ligand-NKR interactions determines NK cell activation or tolerance. Imaging experiments over decades have shown micron and sub-micron scale spatial clustering of activating and inhibitory NKRs. The mechanistic roles of these clusters in affecting downstream signaling and activation are often unclear. To this end, we developed a predictive in silico framework by combining spatially resolved mechanistic agent based modeling, published TIRF imaging data, and parameter estimation to determine mechanisms by which formation and spatial movements of activating NKG2D microclusters affect early time NKG2D signaling kinetics in a human cell line NKL. We show co-clustering of NKG2D and the guanosine nucleotide exchange factor Vav1 in NKG2D microclusters plays a dominant role over ligand (ULBP3) rebinding in increasing production of phospho-Vav1(pVav1), an activation marker of early NKG2D signaling. The in silico model successfully predicts several scenarios of inhibition of NKG2D signaling and time course of NKG2D spatial clustering over a short (~3 min) interval. Modeling shows the presence of a spatial positive feedback relating formation and centripetal movements of NKG2D microclusters, and pVav1 production offers flexibility towards suppression of activating signals by inhibitory KIR ligands organized in inhomogeneous spatial patterns (e.g., a ring). Our in silico framework marks a major improvement in developing spatiotemporal signaling models with quantitatively estimated model parameters using imaging data. Natural Killer cells are lymphocytes of our innate immunity and provide important resistance against viral infections and tumors. NK cells scan the local environment with diverse activating and inhibitory NK cell receptors (NKRs) and remain tolerized or lyse target cells expressing cognate ligands to NKRs. NKRs have been found to form micron sized clusters (or microclusters) as they interact with cognate ligands, and mechanisms regarding how the formation and movements of these microclusters influence NK cell signaling and activation, specifically related to activating NKRs, are often unclear. To this end, we develop a predictive spatially resolved early-time NK cell signaling model to study the interplay between membrane-proximal biochemical signaling events and the kinetics of microclusters of activating NKG2D and inhibitory KIR2DL2 receptors. We used published TIRF imaging data to validate our in silico models and estimate model parameters. Predictions from multiple in silico models are tested against a variety of data obtained from published imaging experiments and immunoassays. Our analysis suggests co-clustering of NKG2D and the guanosine nucleotide exchange factor Vav1 in the microclusters plays a major role in enhancing downstream activating signals. The developed framework can be extended to describe spatiotemporal signaling for other activating NKRs including CD16.
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Affiliation(s)
- Rajdeep Kaur Grewal
- Battelle Center for Mathematical Medicine, Abigail Wexner Research Institute, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Jayajit Das
- Battelle Center for Mathematical Medicine, Abigail Wexner Research Institute, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
- Pelotonia Institute for Immuno-Oncology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Graduate Program, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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6
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Suter EC, Schmid EM, Harris AR, Voets E, Francica B, Fletcher DA. Antibody:CD47 ratio regulates macrophage phagocytosis through competitive receptor phosphorylation. Cell Rep 2021; 36:109587. [PMID: 34433055 PMCID: PMC8477956 DOI: 10.1016/j.celrep.2021.109587] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 04/19/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023] Open
Abstract
Cancer immunotherapies often modulate macrophage effector function by introducing either targeting antibodies that activate Fcγ receptors (FcγRs) or blocking antibodies that disrupt inhibitory SIRPα-CD47 engagement. However, how these competing signals are integrated is poorly understood, raising questions about how to effectively titrate immune responses. Here, we find that macrophage phagocytic decisions are regulated by the ratio of activating ligand to inhibitory ligand over a broad range of absolute molecular densities. Using both endogenous and chimeric receptors, we show that activating:inhibitory ligand ratios of at least 10:1 are required to promote phagocytosis of model antibody-opsonized CD47-inhibited targets and that lowering that ratio reduces FcγR phosphorylation because of inhibitory phosphatases recruited to CD47-bound SIRPα. We demonstrate that ratiometric signaling is critical for phagocytosis of tumor cells and can be modified by blocking SIRPα, indicating that balancing targeting and blocking antibodies may be important for controlling macrophage phagocytosis in cancer immunotherapy.
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Affiliation(s)
- Emily C Suter
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA; UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA
| | - Eva M Schmid
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA
| | - Andrew R Harris
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA; Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, ON, Canada
| | - Erik Voets
- Aduro Biotech Europe, Oss, the Netherlands
| | | | - Daniel A Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA; UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
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7
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Toledo E, Le Saux G, Edri A, Li L, Rosenberg M, Keidar Y, Bhingardive V, Radinsky O, Hadad U, Di Primo C, Buffeteau T, Smith AS, Porgador A, Schvartzman M. Molecular-scale spatio-chemical control of the activating-inhibitory signal integration in NK cells. SCIENCE ADVANCES 2021; 7:7/24/eabc1640. [PMID: 34117052 PMCID: PMC8195486 DOI: 10.1126/sciadv.abc1640] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/21/2021] [Indexed: 05/13/2023]
Abstract
The role of juxtaposition of activating and inhibitory receptors in signal inhibition of cytotoxic lymphocytes remains strongly debated. The challenge lies in the lack of tools that allow simultaneous spatial manipulation of signaling molecules. To circumvent this, we produced a nanoengineered multifunctional platform with molecular-scale spatial control of ligands, which was applied to elucidate KIR2DL1-mediated inhibition of NKG2D signaling-receptors of natural killer cells. This platform was conceived by bimetallic nanodot patterning with molecular-scale registry, followed by a ternary functionalization with distinct moieties. We found that a 40-nm gap between activating and inhibitory ligands provided optimal inhibitory conditions. Supported by theoretical modeling, we interpret these findings as a consequence of the size mismatch and conformational flexibility of ligands in their spatial interaction. This highly versatile approach provides an important insight into the spatial mechanism of inhibitory immune checkpoints, which is essential for the rational design of future immunotherapies.
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Affiliation(s)
- Esti Toledo
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Guillaume Le Saux
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Avishay Edri
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Science, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Long Li
- Department of Physics, IZNF, FAU Erlangen-Nürnberg, Erlangen 91058, Germany
- Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Maor Rosenberg
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Yossi Keidar
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Viraj Bhingardive
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Olga Radinsky
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Science, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Uzi Hadad
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Carmelo Di Primo
- University of Bordeaux, INSERM U1212, UMR CNRS 5320, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac, France
| | | | - Ana-Sunčana Smith
- Department of Physics, IZNF, FAU Erlangen-Nürnberg, Erlangen 91058, Germany
- Group for Computational Life Sciences, Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, Zagreb 10000, Croatia
| | - Angel Porgador
- The Shraga Segal Department of Microbiology, Immunology, and Genetics, Faculty of Health Science, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Mark Schvartzman
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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8
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Kennedy PR, Barthen C, Williamson DJ, Pitkeathly WTE, Hazime KS, Cumming J, Stacey KB, Hilton HG, Carrington M, Parham P, Davis DM. Genetic diversity affects the nanoscale membrane organization and signaling of natural killer cell receptors. Sci Signal 2019; 12:eaaw9252. [PMID: 31848320 PMCID: PMC6944503 DOI: 10.1126/scisignal.aaw9252] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genetic diversity in human natural killer (NK) cell receptors is linked to resistance and susceptibility to many diseases. Here, we tested the effect of this diversity on the nanoscale organization of killer cell immunoglobulin-like receptors (KIRs). Using superresolution microscopy, we found that inhibitory KIRs encoded by different genes and alleles were organized differently at the surface of primary human NK cells. KIRs that were found at low abundance assembled into smaller clusters than those formed by KIRs that were more highly abundant, and at low abundance, there was a greater proportion of KIRs in clusters. Upon receptor triggering, a structured interface called the immune synapse assembles, which facilitates signal integration and controls NK cell responses. Here, triggering of low-abundance receptors resulted in less phosphorylation of the downstream phosphatase SHP-1 but more phosphorylation of the adaptor protein Crk than did triggering of high-abundance receptors. In cells with greater KIR abundance, SHP-1 dephosphorylated Crk, which potentiated NK cell spreading during activation. Thus, genetic variation modulates both the abundance and nanoscale organization of inhibitory KIRs. That is, as well as the number of receptors at the cell surface varying with genotype, the way in which these receptors are organized in the membrane also varies. Essentially, a change in the average surface abundance of a protein at the cell surface is a coarse descriptor entwined with changes in local nanoscale clustering. Together, our data indicate that genetic diversity in inhibitory KIRs affects membrane-proximal signaling and, unexpectedly, the formation of activating immune synapses.
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Affiliation(s)
- Philippa R Kennedy
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Charlotte Barthen
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - David J Williamson
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - William T E Pitkeathly
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Khodor S Hazime
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Joshua Cumming
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Kevin B Stacey
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Hugo G Hilton
- Department of Structural Biology, Stanford University School of Medicine, D159, Sherman Fairchild Science Building, 299 Campus Drive West, Stanford, CA 94305, USA
| | - Mary Carrington
- Basic Science Program, Frederick National Laboratory for Cancer Research, Building 560, Room 21-89, Frederick, MD 21702, USA
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139, USA
| | - Peter Parham
- Department of Structural Biology, Stanford University School of Medicine, D159, Sherman Fairchild Science Building, 299 Campus Drive West, Stanford, CA 94305, USA
| | - Daniel M Davis
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK.
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9
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Osmani N, Follain G, García León MJ, Lefebvre O, Busnelli I, Larnicol A, Harlepp S, Goetz JG. Metastatic Tumor Cells Exploit Their Adhesion Repertoire to Counteract Shear Forces during Intravascular Arrest. Cell Rep 2019; 28:2491-2500.e5. [DOI: 10.1016/j.celrep.2019.07.102] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 05/28/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022] Open
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10
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Membrane Organization and Physical Regulation of Lymphocyte Antigen Receptors: A Biophysicist's Perspective. J Membr Biol 2019; 252:397-412. [PMID: 31352492 DOI: 10.1007/s00232-019-00085-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/18/2019] [Indexed: 12/19/2022]
Abstract
Receptors at the membrane of immune cells are the central players of innate and adaptative immunity, providing effective defence mechanisms against pathogens or cancer cells. Their function is intimately linked to their position at and within the membrane which provides accessibility, mobility as well as membrane proximal cytoskeleton anchoring, all of these elements playing important roles in the final function and links to cellular actions. Understanding how immune cells integrate the specific signals received at their membrane to take a decision remains an immense challenge and a very active field of fundamental and applied research. Recent progress in imaging and micromanipulation techniques have led to an unprecedented refinement in the description of molecular structures and supramolecular assemblies at the immune cell membrane, and provided a glimpse into their dynamics and regulation by force. Several key elements have been scrutinized such as the roles of relative sizes of molecules, lateral organisation, motion in the membrane of the receptors, but also physical cues such as forces, mediated by cellular substrates of different rigidities or applied by the cell itself, in conjunction with its partner cell. We review here these recent discoveries associated with a description of the biophysical methods used. While a conclusive picture integrating all of these components is still lacking, mainly due to the implication of diverse and different mechanisms and spatio-temporal scales involved, the amount of quantitative data available opens the way for physical modelling and numerical simulations and new avenues for experimental research.
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11
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Size-Dependent Segregation Controls Macrophage Phagocytosis of Antibody-Opsonized Targets. Cell 2019; 174:131-142.e13. [PMID: 29958103 DOI: 10.1016/j.cell.2018.05.059] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/20/2018] [Accepted: 05/29/2018] [Indexed: 12/18/2022]
Abstract
Macrophages protect the body from damage and disease by targeting antibody-opsonized cells for phagocytosis. Though antibodies can be raised against antigens with diverse structures, shapes, and sizes, it is unclear why some are more effective at triggering immune responses than others. Here, we define an antigen height threshold that regulates phagocytosis of both engineered and cancer-specific antigens by macrophages. Using a reconstituted model of antibody-opsonized target cells, we find that phagocytosis is dramatically impaired for antigens that position antibodies >10 nm from the target surface. Decreasing antigen height drives segregation of antibody-bound Fc receptors from the inhibitory phosphatase CD45 in an integrin-independent manner, triggering Fc receptor phosphorylation and promoting phagocytosis. Our work shows that close contact between macrophage and target is a requirement for efficient phagocytosis, suggesting that therapeutic antibodies should target short antigens in order to trigger Fc receptor activation through size-dependent physical segregation.
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12
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Felce JH, Sezgin E, Wane M, Brouwer H, Dustin ML, Eggeling C, Davis SJ. CD45 exclusion- and cross-linking-based receptor signaling together broaden FcεRI reactivity. Sci Signal 2018; 11:11/561/eaat0756. [PMID: 30563863 DOI: 10.1126/scisignal.aat0756] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
For many years, the high-affinity receptor for immunoglobulin E (IgE) FcεRI, which is expressed by mast cells and basophils, has been widely held to be the exemplar of cross-linking (that is, aggregation dependent) signaling receptors. We found, however, that FcεRI signaling could occur in the presence or absence of receptor cross-linking. Using both cell and cell-free systems, we showed that FcεRI signaling was stimulated by surface-associated monovalent ligands through the passive, size-dependent exclusion of the receptor-type tyrosine phosphatase CD45 from plasma membrane regions of FcεRI-ligand engagement. Similarly to the T cell receptor, FcεRI signaling could also be initiated in a ligand-independent manner. These data suggest that a simple mechanism of CD45 exclusion-based receptor triggering could function together with cross-linking-based FcεRI signaling, broadening mast cell and basophil reactivity by enabling these cells to respond to both multivalent and surface-presented monovalent antigens. These findings also strengthen the case that a size-dependent, phosphatase exclusion-based receptor triggering mechanism might serve generally to facilitate signaling by noncatalytic immune receptors.
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Affiliation(s)
- James H Felce
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.,Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Erdinc Sezgin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Madina Wane
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Heather Brouwer
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK.
| | - Christian Eggeling
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| | - Simon J Davis
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK. .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
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13
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Junghans V, Santos AM, Lui Y, Davis SJ, Jönsson P. Dimensions and Interactions of Large T-Cell Surface Proteins. Front Immunol 2018; 9:2215. [PMID: 30319654 PMCID: PMC6170634 DOI: 10.3389/fimmu.2018.02215] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 09/06/2018] [Indexed: 11/23/2022] Open
Abstract
The first step of the adaptive immune response involves the interaction of T cells that express T-cell receptors (TCRs) with peptide-loaded major histocompatibility complexes expressed by antigen-presenting cells (APCs). Exactly how this leads to activation of the TCR and to downstream signaling is uncertain, however. Recent findings suggest that one of the key events is the exclusion of the large receptor-type tyrosine phosphatase CD45, from close contacts formed at sites of T-cell/APC interaction. If this is true, a full understanding of how close contact formation leads to signaling would require insights into the structures of, and interactions between, large membrane proteins like CD45 and other proteins forming the glycocalyx, such as CD43. Structural insights into the overall dimensions of these proteins using crystallographic methods are hard to obtain, and their conformations on the cell surface are also unknown. Several imaging-based optical microscopy techniques have however been developed for analyzing protein dimensions and orientation on model cell surfaces with nanometer precision. Here we review some of these methods with a focus on the use of hydrodynamic trapping, which relies on liquid flow from a micropipette to move and trap membrane-associated fluorescently labeled molecules. Important insights that have been obtained include (i) how protein flexibility and coverage might affect the effective heights of these molecules, (ii) the height of proteins on the membrane as a key parameter determining how they will distribute in cell-cell contacts, and (iii) how repulsive interactions between the extracellular parts of the proteins influences protein aggregation and distribution.
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Affiliation(s)
| | - Ana Mafalda Santos
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Yuan Lui
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Simon J. Davis
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
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14
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Le Saux G, Edri A, Keydar Y, Hadad U, Porgador A, Schvartzman M. Spatial and Chemical Surface Guidance of NK Cell Cytotoxic Activity. ACS APPLIED MATERIALS & INTERFACES 2018; 10:11486-11494. [PMID: 29557634 DOI: 10.1021/acsami.7b19643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Studying how different signaling pathways spatially integrate in cells requires selective manipulation and control of different transmembrane ligand-receptor pairs at the same time. This work explores a novel method for precisely arranging two arbitrarily chosen ligands on a micron-scale two-dimensional pattern. The approach is based on lithographic patterning of Au and TiO2 films, followed by their selective functionalization with Ni-nitrilotriacetic acid-histidine and biotin-avidin chemistries, respectively. The selectivity of chemical and biological functionalizations is demonstrated by X-ray photoelectron spectroscopy and immunofluorescence imaging, respectively. This approach is applied to produce the first type of bifunctional surfaces with controllably positioned ligands for activating the receptors of natural killer (NK) immune cells. NK cells were used as a model system to demonstrate the potency of the surface in guiding site-selective cell attachment and activation. Upon applying the suitable ligand or ligand combination, the surfaces guided the appropriate single- or bifunctional attachment and activation. These encouraging results demonstrate the effectiveness of the system as an experimental platform aimed at the comprehensive understanding of the immunological synapse. The great simplicity, modularity, and specificity of this approach make it applicable for a myriad of combinations of other biomolecules and applications, turning it into the "Swiss knife" of biointerfaces.
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15
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Bálint Š, Lopes FB, Davis DM. A nanoscale reorganization of the IL-15 receptor is triggered by NKG2D in a ligand-dependent manner. Sci Signal 2018; 11:11/525/eaal3606. [PMID: 29636390 DOI: 10.1126/scisignal.aal3606] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Natural killer group 2D (NKG2D), an activating receptor on natural killer (NK) cells and a subset of T cells, recognizes stress-inducible proteins, including MICA and ULBP2, which are present on infected or transformed cells. Whether each NKG2D ligand (NKG2DL) has a distinct biological role is not clear. Using superresolution microscopy, we found that NKG2D is constitutively arranged in nanoclusters at the surface of human primary NK cells. Nanoclusters of NKG2D became smaller upon ligation with MICA but became larger upon activation by ULBP2. In addition, ULBP2 induced the reorganization of nanoclusters of the cytokine receptor subunit for both interleukin-2 (IL-2) and IL-15 (IL-2/IL-15Rβ), such that these cytokine receptor subunits coalesced with nanoclusters of NKG2D. Functionally, the response of NK cells activated by ULBP2 was augmented by an interaction between ULBP2-bound NKG2D and IL-15R ligated by IL-15 (trans-presented by IL-15Rα-coated surfaces). These data suggest that NKG2DLs are not equivalent in their capacity to activate NKG2D and establish a previously unknown paradigm in how ligand-induced changes to the nanoscale organization of the cell surface can affect immune responses.
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Affiliation(s)
- Štefan Bálint
- Manchester Collaborative Centre for Inflammation Research, The University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Filipa B Lopes
- Manchester Collaborative Centre for Inflammation Research, The University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Daniel M Davis
- Manchester Collaborative Centre for Inflammation Research, The University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK.
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16
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Spiess M, Hernandez-Varas P, Oddone A, Olofsson H, Blom H, Waithe D, Lock JG, Lakadamyali M, Strömblad S. Active and inactive β1 integrins segregate into distinct nanoclusters in focal adhesions. J Cell Biol 2018; 217:1929-1940. [PMID: 29632027 PMCID: PMC5987715 DOI: 10.1083/jcb.201707075] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 02/16/2018] [Accepted: 03/26/2018] [Indexed: 01/24/2023] Open
Abstract
Through two superresolution microscopy techniques, STED and STORM, Spiess et al. visualize the organization of integrins in focal adhesions and show that active and inactive β1 integrins assemble into distinct nanoclusters within adhesions, suggesting the existence of a novel mechanism that locally coordinates integrin activity. Integrins are the core constituents of cell–matrix adhesion complexes such as focal adhesions (FAs) and play key roles in physiology and disease. Integrins fluctuate between active and inactive conformations, yet whether the activity state influences the spatial organization of integrins within FAs has remained unclear. In this study, we address this question and also ask whether integrin activity may be regulated either independently for each integrin molecule or through locally coordinated mechanisms. We used two distinct superresolution microscopy techniques, stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion microscopy (STED), to visualize active versus inactive β1 integrins. We first reveal a spatial hierarchy of integrin organization with integrin molecules arranged in nanoclusters, which align to form linear substructures that in turn build FAs. Remarkably, within FAs, active and inactive β1 integrins segregate into distinct nanoclusters, with active integrin nanoclusters being more organized. This unexpected segregation indicates synchronization of integrin activities within nanoclusters, implying the existence of a coordinate mechanism of integrin activity regulation.
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Affiliation(s)
- Matthias Spiess
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Pablo Hernandez-Varas
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.,Wolfson Imaging Centre, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, England, UK
| | - Anna Oddone
- Institut de Ciències Fotòniques, Barcelona, Spain
| | - Helene Olofsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Hans Blom
- Science for Life Laboratory, Royal Institute of Technology, Solna, Sweden
| | - Dominic Waithe
- Wolfson Imaging Centre, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, England, UK
| | - John G Lock
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | | | - Staffan Strömblad
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
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17
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Wałajtys-Rode E, Dzik JM. Monocyte/Macrophage: NK Cell Cooperation-Old Tools for New Functions. Results Probl Cell Differ 2017; 62:73-145. [PMID: 28455707 DOI: 10.1007/978-3-319-54090-0_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Monocyte/macrophage and natural killer (NK) cells are partners from a phylogenetic standpoint of innate immune system development and its evolutionary progressive interaction with adaptive immunity. The equally conservative ways of development and differentiation of both invertebrate hemocytes and vertebrate macrophages are reviewed. Evolutionary conserved molecules occurring in macrophage receptors and effectors have been inherited by vertebrates after their common ancestor with invertebrates. Cytolytic functions of mammalian NK cells, which are rooted in immune cells of invertebrates, although certain NK cell receptors (NKRs) are mammalian new events, are characterized. Broad heterogeneity of macrophage and NK cell phenotypes that depends on surrounding microenvironment conditions and expression profiles of specific receptors and activation mechanisms of both cell types are discussed. The particular tissue specificity of macrophages and NK cells, as well as their plasticity and mechanisms of their polarization to different functional subtypes have been underlined. The chapter summarized studies revealing the specific molecular mechanisms and regulation of NK cells and macrophages that enable their highly specific cross-cooperation. Attention is given to the evolving role of human monocyte/macrophage and NK cell interaction in pathogenesis of hypersensitivity reaction-based disorders, including autoimmunity, as well as in cancer surveillance and progression.
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Affiliation(s)
- Elżbieta Wałajtys-Rode
- Faculty of Chemistry, Department of Drug Technology and Biotechnology, Warsaw University of Technology, Noakowskiego 3 Str, 00-664, Warsaw, Poland.
| | - Jolanta M Dzik
- Faculty of Agriculture and Biology, Department of Biochemistry, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
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18
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Goyette J, Gaus K. Mechanisms of protein nanoscale clustering. Curr Opin Cell Biol 2016; 44:86-92. [PMID: 27666166 DOI: 10.1016/j.ceb.2016.09.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/08/2016] [Indexed: 12/22/2022]
Abstract
Due to recent technical developments in microscopy, huge advances have been made in our understanding of the architecture of the cell membrane. It is now well appreciated that nanoscale clustering is a common feature of membrane proteins. Many of these clusters have been implicated in signal initiation and integration platforms. However, the mechanisms that mediate the dynamic nanoscale arrangement of membrane proteins are not fully understood and could involve lipid domains, electrostatic interactions between proteins and lipid, protein scaffolding as well as purely mechanical processes. In this review we summarise these mechanisms giving rise to dynamic nanoscale protein reorganisation in the plasma membrane with reference to recent examples of immune receptor clustering to illustrate general principles.
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Affiliation(s)
- Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney 2052, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney 2052, Australia.
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19
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Oszmiana A, Williamson DJ, Cordoba SP, Morgan DJ, Kennedy PR, Stacey K, Davis DM. The Size of Activating and Inhibitory Killer Ig-like Receptor Nanoclusters Is Controlled by the Transmembrane Sequence and Affects Signaling. Cell Rep 2016; 15:1957-72. [PMID: 27210755 PMCID: PMC4893158 DOI: 10.1016/j.celrep.2016.04.075] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 03/15/2016] [Accepted: 04/20/2016] [Indexed: 01/24/2023] Open
Abstract
Super-resolution microscopy has revealed that immune cell receptors are organized in nanoscale clusters at cell surfaces and immune synapses. However, mechanisms and functions for this nanoscale organization remain unclear. Here, we used super-resolution microscopy to compare the surface organization of paired killer Ig-like receptors (KIR), KIR2DL1 and KIR2DS1, on human primary natural killer cells and cell lines. Activating KIR2DS1 assembled in clusters two-fold larger than its inhibitory counterpart KIR2DL1. Site-directed mutagenesis established that the size of nanoclusters is controlled by transmembrane amino acid 233, a lysine in KIR2DS1. Super-resolution microscopy also revealed two ways in which the nanoscale clustering of KIR affects signaling. First, KIR2DS1 and DAP12 nanoclusters are juxtaposed in the resting cell state but coalesce upon receptor ligation. Second, quantitative super-resolution microscopy revealed that phosphorylation of the kinase ZAP-70 or phosphatase SHP-1 is favored in larger KIR nanoclusters. Thus, the size of KIR nanoclusters depends on the transmembrane sequence and affects downstream signaling. Activating and inhibitory NK cell receptors have a distinct nanoscale organization The transmembrane sequence of KIR controls their nanoscale organization Nanoclusters of KIR2DS1 and its adaptor are juxtaposed but mix upon activation Phosphorylation of ZAP-70 or SHP-1 is favored in larger receptor nanoclusters
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Affiliation(s)
- Anna Oszmiana
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - David J Williamson
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Shaun-Paul Cordoba
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, UK
| | - David J Morgan
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Philippa R Kennedy
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Kevin Stacey
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
| | - Daniel M Davis
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK.
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20
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Comrie WA, Burkhardt JK. Action and Traction: Cytoskeletal Control of Receptor Triggering at the Immunological Synapse. Front Immunol 2016; 7:68. [PMID: 27014258 PMCID: PMC4779853 DOI: 10.3389/fimmu.2016.00068] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/12/2016] [Indexed: 01/03/2023] Open
Abstract
It is well known that F-actin dynamics drive the micron-scale cell shape changes required for migration and immunological synapse (IS) formation. In addition, recent evidence points to a more intimate role for the actin cytoskeleton in promoting T cell activation. Mechanotransduction, the conversion of mechanical input into intracellular biochemical changes, is thought to play a critical role in several aspects of immunoreceptor triggering and downstream signal transduction. Multiple molecules associated with signaling events at the IS have been shown to respond to physical force, including the TCR, costimulatory molecules, adhesion molecules, and several downstream adapters. In at least some cases, it is clear that the relevant forces are exerted by dynamics of the T cell actomyosin cytoskeleton. Interestingly, there is evidence that the cytoskeleton of the antigen-presenting cell also plays an active role in T cell activation, by countering the molecular forces exerted by the T cell at the IS. Since actin polymerization is itself driven by TCR and costimulatory signaling pathways, a complex relationship exists between actin dynamics and receptor activation. This review will focus on recent advances in our understanding of the mechanosensitive aspects of T cell activation, paying specific attention to how F-actin-directed forces applied from both sides of the IS fit into current models of receptor triggering and activation.
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Affiliation(s)
- William A Comrie
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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21
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Brzostek J, Gascoigne NRJ, Rybakin V. Cell Type-Specific Regulation of Immunological Synapse Dynamics by B7 Ligand Recognition. Front Immunol 2016; 7:24. [PMID: 26870040 PMCID: PMC4740375 DOI: 10.3389/fimmu.2016.00024] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/18/2016] [Indexed: 01/07/2023] Open
Abstract
B7 proteins CD80 (B7-1) and CD86 (B7-2) are expressed on most antigen-presenting cells and provide critical co-stimulatory or inhibitory input to T cells via their T-cell-expressed receptors: CD28 and CTLA-4. CD28 is expressed on effector T cells and regulatory T cells (Tregs), and CD28-dependent signals are required for optimum activation of effector T cell functions. CD28 ligation on effector T cells leads to formation of distinct molecular patterns and induction of cytoskeletal rearrangements at the immunological synapse (IS). CD28 plays a critical role in recruitment of protein kinase C (PKC)-θ to the effector T cell IS. CTLA-4 is constitutively expressed on the surface of Tregs, but it is expressed on effector T cells only after activation. As CTLA-4 binds to B7 proteins with significantly higher affinity than CD28, B7 ligand recognition by cells expressing both receptors leads to displacement of CD28 and PKC-θ from the IS. In Tregs, B7 ligand recognition leads to recruitment of CTLA-4 and PKC-η to the IS. CTLA-4 plays a role in regulation of T effector and Treg IS stability and cell motility. Due to their important roles in regulating T-cell-mediated responses, B7 receptors are emerging as important drug targets in oncology. In this review, we present an integrated summary of current knowledge about the role of B7 family receptor–ligand interactions in the regulation of spatial and temporal IS dynamics in effector and Tregs.
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Affiliation(s)
- Joanna Brzostek
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine and Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Nicholas R J Gascoigne
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine and Immunology Programme, National University of Singapore , Singapore , Singapore
| | - Vasily Rybakin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine and Immunology Programme, National University of Singapore, Singapore, Singapore; Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
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22
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Lim HS, Cordoba SP, Dushek O, Goyette J, Taylor A, Rudd CE, van der Merwe PA. Costimulation of IL-2 Production through CD28 Is Dependent on the Size of Its Ligand. THE JOURNAL OF IMMUNOLOGY 2015; 195:5432-9. [PMID: 26500347 PMCID: PMC4654228 DOI: 10.4049/jimmunol.1500707] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 09/22/2015] [Indexed: 11/25/2022]
Abstract
Optimal T cell activation typically requires engagement of both the TCR and costimulatory receptors, such as CD28. Engagement of CD28 leads to tyrosine phosphorylation of its cytoplasmic region and recruitment of cytoplasmic signaling proteins. Although the exact mechanism of CD28 signal transduction is unknown, CD28 triggering has similarities to the TCR, which was proposed to use the kinetic-segregation (KS) mechanism. The KS model postulates that, when small receptors engage their ligands within areas of close (∼15 nm) contact in the T cell/APC interface, this facilitates phosphorylation by segregating the engaged receptor/ligand complex from receptor protein tyrosine phosphatases with large ectodomains, such as CD45. To test this hypothesis, we examined the effect of elongating the extracellular region of the CD28 ligand, CD80, on its ability to costimulate IL-2 production by primary T cells. CD80 elongation reduced its costimulatory effect without abrogating CD28 binding. Confocal microscopy revealed that elongated CD80 molecules were less well segregated from CD45 at the T cell/APC interface. T cells expressing CD28 harboring a key tyrosine-170 mutation were less sensitive to CD80 elongation. In summary, the effectiveness of CD28 costimulation is inversely proportional to the dimensions of the CD28-CD80 complex. Small CD28-CD80 complex dimensions are required for optimal costimulation by segregation from large inhibitory tyrosine phosphatases. These results demonstrate the importance of ligand dimensions for optimal costimulation of IL-2 production by T cells and suggest that the KS mechanism contributes to CD28 signaling.
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Affiliation(s)
- Hong-Sheng Lim
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Shaun-Paul Cordoba
- University College London Cancer Institute, University College London, London WC1E 6DD, United Kingdom; and
| | - Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Jesse Goyette
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Alison Taylor
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - Christopher E Rudd
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
| | - P Anton van der Merwe
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom;
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23
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Gras Navarro A, Björklund AT, Chekenya M. Therapeutic potential and challenges of natural killer cells in treatment of solid tumors. Front Immunol 2015; 6:202. [PMID: 25972872 PMCID: PMC4413815 DOI: 10.3389/fimmu.2015.00202] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 04/14/2015] [Indexed: 12/22/2022] Open
Abstract
Natural killer (NK) cells are innate lymphoid cells that hold tremendous potential for effective immunotherapy for a broad range of cancers. Due to the mode of NK cell killing, requiring one-to-one target engagement and site-directed release of cytolytic granules, the therapeutic potential of NK cells has been most extensively explored in hematological malignancies. However, their ability to precisely kill antibody coated cells, cancer stem cells, and genotoxically altered cells, while maintaining tolerance to healthy cells makes them appealing therapeutic effectors for all cancer forms, including metastases. Due to their release of pro-inflammatory cytokines, NK cells may potently reverse the anti-inflammatory tumor microenvironment (TME) and augment adaptive immune responses by promoting differentiation, activation, and/or recruitment of accessory immune cells to sites of malignancy. Nevertheless, integrated and coordinated mechanisms of subversion of NK cell activity against the tumor and its microenvironment exist. Although our understanding of the receptor ligand interactions that regulate NK cell functionality has evolved remarkably, the diversity of ligands and receptors is complex, as is their mechanistic foundations in regulating NK cell function. In this article, we review the literature and highlight how the TME manipulates the NK cell phenotypes, genotypes, and tropism to evade tumor recognition and elimination. We discuss counter strategies that may be adopted to augment the efficacy of NK cell anti-tumor surveillance, the clinical trials that have been undertaken so far in solid malignancies, critically weighing the challenges and opportunities with this approach.
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Affiliation(s)
| | - Andreas T Björklund
- Karolinska University Hospital, Hematology Center and Karolinska Institute , Stockholm , Sweden
| | - Martha Chekenya
- Department of Biomedicine, University of Bergen , Bergen , Norway
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24
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The immune synapse clears and excludes molecules above a size threshold. Nat Commun 2014; 5:5479. [PMID: 25407222 PMCID: PMC4248232 DOI: 10.1038/ncomms6479] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/06/2014] [Indexed: 12/21/2022] Open
Abstract
Natural killer cells assess target cell health via interactions at the immune synapse (IS) that facilitates signal integration and directed secretion. Here we test whether the IS also functions as a gasket. Quantitative fluorescence microscopy of nanometer-scale dextrans within synapses formed by various effector-target cell conjugates reveal that molecules are excluded in a size-dependent manner at activating synapses. Dextran sized ≤4 nm move in and out of the IS, but access is significantly reduced (by >50%) for dextran sized 10–13 nm, and dextran ≥32 nm is almost entirely excluded. Depolymerization of F-actin abrogated exclusion. Unexpectedly, larger-sized dextrans are cleared as the IS assembles in a zipper-like manner. Monoclonal antibodies are also excluded from the IS but smaller single-domain antibodies are able to penetrate. Therefore, the IS can clear and exclude molecules above a size threshold, and drugs designed to target synaptic cytokines or cytotoxic proteins must fit these dimensions. Natural killer cells can be switched on or off by the immune synapse formed with another cell. Here, the authors show that when a natural killer cell is activated, the immune synapse also functions to clear and exclude extracellular molecules, including antibodies, in a size-dependent manner.
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25
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Gras Navarro A, Kmiecik J, Leiss L, Zelkowski M, Engelsen A, Bruserud Ø, Zimmer J, Enger PØ, Chekenya M. NK cells with KIR2DS2 immunogenotype have a functional activation advantage to efficiently kill glioblastoma and prolong animal survival. THE JOURNAL OF IMMUNOLOGY 2014; 193:6192-206. [PMID: 25381437 DOI: 10.4049/jimmunol.1400859] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glioblastomas (GBMs) are lethal brain cancers that are resistant to current therapies. We investigated the cytotoxicity of human allogeneic NK cells against patient-derived GBM in vitro and in vivo, as well as mechanisms mediating their efficacy. We demonstrate that KIR2DS2 immunogenotype NK cells were more potent killers, notwithstanding the absence of inhibitory killer Ig-like receptor (KIR)-HLA ligand mismatch. FACS-sorted and enriched KIR2DS2(+) NK cell subpopulations retained significantly high levels of CD69 and CD16 when in contact with GBM cells at a 1:1 ratio and highly expressed CD107a and secreted more soluble CD137 and granzyme A. In contrast, KIR2DS2(-) immunogenotype donor NK cells were less cytotoxic against GBM and K562, and, similar to FACS-sorted or gated KIR2DS2(-) NK cells, significantly diminished CD16, CD107a, granzyme A, and CD69 when in contact with GBM cells. Furthermore, NK cell-mediated GBM killing in vitro depended upon the expression of ligands for the activating receptor NKG2D and was partially abrogated by Ab blockade. Treatment of GBM xenografts in NOD/SCID mice with NK cells from a KIR2DS2(+) donor lacking inhibitory KIR-HLA ligand mismatch significantly prolonged the median survival to 163 d compared with vehicle controls (log-rank test, p = 0.0001), in contrast to 117.5 d (log-rank test, p = 0.0005) for NK cells with several inhibitory KIR-HLA ligand mismatches but lacking KIR2DS2 genotype. Significantly more CD56(+)CD16(+) NK cells from a KIR2DS2(+) donor survived in nontumor-bearing brains 3 wk after infusion compared with KIR2DS2(-) NK cells, independent of their proliferative capacity. In conclusion, KIR2DS2 identifies potent alloreactive NK cells against GBM that are mediated by commensurate, but dominant, activating signals.
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Affiliation(s)
| | - Justyna Kmiecik
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Lina Leiss
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway; Department of Neurology and Neurosurgery, Haukeland University Hospital, 5021 Bergen, Norway
| | - Mateusz Zelkowski
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Agnete Engelsen
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Øystein Bruserud
- Department of Haematology, Haukeland University Hospital, 5021 Bergen, Norway; and
| | - Jacques Zimmer
- Laboratory of Immunogenetics and Allergology, Public Research Centre for Health, L-1445, Luxembourg, Luxembourg
| | - Per Øyvind Enger
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway; Department of Neurology and Neurosurgery, Haukeland University Hospital, 5021 Bergen, Norway
| | - Martha Chekenya
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway;
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26
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Davies JOJ, Stringaris K, Barrett AJ, Rezvani K. Opportunities and limitations of natural killer cells as adoptive therapy for malignant disease. Cytotherapy 2014; 16:1453-1466. [PMID: 24856895 DOI: 10.1016/j.jcyt.2014.03.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 10/25/2022]
Abstract
Although natural killer (NK) cells can be readily generated for adoptive therapy with current techniques, their optimal application to treat malignant diseases requires an appreciation of the dynamic balance between signals that either synergize with or antagonize each other. Individuals display wide differences in NK function that determine their therapeutic efficacy. The ability of NK cells to kill target cells or produce cytokines depends on the balance between signals from activating and inhibitory cell-surface receptors. The selection of NK cells with a predominant activating profile is critical for delivering successful anti-tumor activity. This can be achieved through selection of killer immunoglobulin-like receptor-mismatched NK donors and by use of blocking molecules against inhibitory pathways. Optimum NK cytotoxicity may require licensing or priming with tumor cells. Recent discoveries in the molecular and cellular biology of NK cells inform in the design of new strategies, including adjuvant therapies, to maximize the cytotoxic potential of NK cells for adoptive transfer to treat human malignancies.
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Affiliation(s)
- James O J Davies
- Department of Haematology, Imperial College London, London, United Kingdom
| | - Kate Stringaris
- Department of Haematology, Imperial College London, London, United Kingdom
| | - A John Barrett
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Katayoun Rezvani
- Stem Cell Transplantation and Cellular Therapy, MD Anderson Cancer Center, Houston, Texas, USA.
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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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28
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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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29
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Cordoba SP, Choudhuri K, Zhang H, Bridge M, Basat AB, Dustin ML, van der Merwe PA. The large ectodomains of CD45 and CD148 regulate their segregation from and inhibition of ligated T-cell receptor. Blood 2013; 121:4295-302. [PMID: 23580664 PMCID: PMC3663424 DOI: 10.1182/blood-2012-07-442251] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 03/25/2013] [Indexed: 11/20/2022] Open
Abstract
T-cell receptor (TCR) triggering results in a cascade of intracellular tyrosine phosphorylation events that ultimately leads to T-cell activation. It is dependent on changes in the relative activities of membrane-associated tyrosine kinases and phosphatases near the engaged TCR. CD45 and CD148 are transmembrane tyrosine phosphatases with large ectodomains that have activatory and inhibitory effects on TCR triggering. This study investigates whether and how the ectodomains of CD45 and CD148 modulate their inhibitory effect on TCR signaling. Expression in T cells of forms of these phosphatases with truncated ectodomains inhibited TCR triggering. In contrast, when these phosphatases were expressed with large ectodomains, they had no inhibitory effect. Imaging studies revealed that truncation of the ectodomains enhanced colocalization of these phosphatases with ligated TCR at the immunological synapse. Our results suggest that the large ectodomains of CD45 and CD148 modulate their inhibitory effect by enabling their passive, size-based segregation from ligated TCR, supporting the kinetic-segregation model of TCR triggering.
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Affiliation(s)
- Shaun-Paul Cordoba
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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30
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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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Abstract
Leukocytes play a critical role in recognizing and responding to infection and cancer. Central to this function is an array of cell-surface receptors that lack sequence homology. Many of these receptors have in common the fact that their signaling involves phosphorylation of cytoplasmic domains by extrinsic tyrosine kinases. These non-catalytic tyrosine-phosphorylated receptors (NTRs) share a number of other features, including small size and optimal stimulation by surface-associated ligands. We argue here that NTRs are also likely to share the same kinetic-segregation triggering mechanism, which involves segregation of the engaged NTR from receptor tyrosine phosphatases with large ectodomains such as CD45 and CD148. NTRs signal through tyrosine-containing cytoplasmic motifs, which recruit distinct cytoplasmic signaling proteins when phosphorylated, transducing activatory or inhibitory signals. They have two features that make them uniquely well suited to their role in immune recognition of infection and cancer. Their modular structure enables the coupling of many rapidly evolving receptors with diverse ligand specificities to the same conserved signaling machinery. Their similarity in size and shared signaling machinery enables them to colocalize at cell-cell interfaces when they engage ligands, facilitating the integration of activatory and inhibitory signals from multiple receptors at the cell surface.
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Affiliation(s)
- Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, UK
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32
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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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33
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Allard J, Dushek O, Coombs D, Anton van der Merwe P. Mechanical modulation of receptor-ligand interactions at cell-cell interfaces. Biophys J 2012; 102:1265-73. [PMID: 22455909 PMCID: PMC3309404 DOI: 10.1016/j.bpj.2012.02.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 02/01/2012] [Accepted: 02/07/2012] [Indexed: 01/13/2023] Open
Abstract
Cell surface receptors have been extensively studied because they initiate and regulate signal transduction cascades leading to a variety of functional cellular outcomes. An important class of immune receptors (e.g., T-cell antigen receptors) whose ligands are anchored to the surfaces of other cells remain poorly understood. The mechanism by which ligand binding initiates receptor phosphorylation, a process termed "receptor triggering", remains controversial. Recently, direct measurements of the (two-dimensional) receptor-ligand complex lifetimes at cell-cell interface were found to be smaller than (three-dimensional) lifetimes in solution but the underlying mechanism is unknown. At the cell-cell interface, the receptor-ligand complex spans a short intermembrane distance (15 nm) compared to long surface molecules (LSMs) whose ectodomains span >40 nm and these LSMs include phosphatases (e.g., CD45) that dephosphorylate the receptor. It has been proposed that size-based segregation of LSMs from a receptor-ligand complex is a mechanism of receptor triggering but it is unclear whether the mechanochemistry supports such small-scale segregation. Here we present a nanometer-scale mathematical model that couples membrane elasticity with the compressional stiffness and lateral mobility of LSMs. We find robust supradiffusive segregation of LSMs from a single receptor-ligand complex. The model predicts that LSM redistribution will result in a time-dependent tension on the complex leading to a decreased two-dimensional lifetime. Interestingly, the model predicts a nonlinear relationship between the three- and two-dimensional lifetimes, which can enhance the ability of receptors to discriminate between similar ligands.
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Affiliation(s)
- Jun F. Allard
- Department of Mathematics, University of California, Davis, California
| | - Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- Centre for Mathematical Biology, University of Oxford, Oxford, United Kingdom
| | - Daniel Coombs
- Department of Mathematics and Institute of Applied Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
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34
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Abstract
The mechanism by which antigen binding to the T cell antigen receptor (TCR) generates intracellular signaling, a process termed TCR triggering, is incompletely understood. A large body of experimental evidence has implicated multiple biophysical/biochemical effects and multiple molecules in the process of TCR triggering, which likely reflect the uniquely demanding role of the TCR in recognizing diverse antigenic ligands. In this perspective, I propose that breaking down the process of TCR triggering into tractable elementary steps may be a useful approach in building mechanistic TCR triggering models. Once these elementary steps are understood, they can be recombined to build a unified model of TCR triggering.
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Affiliation(s)
- Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford Oxford, UK.
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35
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Alakoskela JM, Koner AL, Rudnicka D, Köhler K, Howarth M, Davis DM. Mechanisms for size-dependent protein segregation at immune synapses assessed with molecular rulers. Biophys J 2011; 100:2865-74. [PMID: 21689519 DOI: 10.1016/j.bpj.2011.05.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 04/28/2011] [Accepted: 05/05/2011] [Indexed: 10/18/2022] Open
Abstract
Immunological synapses are specialized intercellular contacts formed by several types of immune cells in contact with target cells or antigen-presenting cells. A late-stage immune synapse is commonly a bulls-eye pattern of immune cell receptor-ligand pairs surrounded by integrin complexes. Based on crystal structures, the intermembrane distance would be ∼15 nm for many immune cell receptor-ligand pairs, but ∼40 nm for integrin-ligand pairs. Close proximity of these two classes of intermembrane bonds would require significant membrane bending and such proteins can segregate according to their size, which may be key for receptor triggering. However, tools available to evaluate the intermembrane organization of the synapse are limited. Here, we present what we believe to be a novel approach to test the importance of size in the intercellular organization of proteins, using live-cell microscopy of a size-series of fluorescently-labeled molecules and quantum dots to act as molecular rulers. Small particles readily colocalized at the synapse with MHC class I bound to its cognate natural killer cell receptor, whereas particles larger than 15 nm were increasingly segregated from this interaction. Combined with modeling of the partitioning of the particles by scaled-particle adsorption theory, these molecular rulers show how membrane-bending elasticity can drive size-dependent exclusion of proteins within immune synapses.
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Affiliation(s)
- Juha-Matti Alakoskela
- Sir Alexander Fleming Building, Division of Cell and Molecular Biology, Imperial College London, London, UK
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36
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Golden-Mason L, Bambha KM, Cheng L, Howell CD, Taylor MW, Clark PJ, Afdhal N, Rosen HR. Natural killer inhibitory receptor expression associated with treatment failure and interleukin-28B genotype in patients with chronic hepatitis C. Hepatology 2011; 54:1559-69. [PMID: 21983945 PMCID: PMC3206734 DOI: 10.1002/hep.24556] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 07/05/2011] [Indexed: 02/06/2023]
Abstract
UNLABELLED Natural killer (NK) cells constitute a first line of defense against viral infections; their function is governed by the integration of signals from multiple activating and inhibitory surface receptors. We hypothesized that because NKs become rapidly activated by cytokines, response to anti-hepatitis C virus (HCV) therapy would be predicted by the phenotype and function of NKs. We used a cohort of 101 patients (55 African, 46 Caucasian-American) who received pegylated-interferon (IFN) and ribavirin for 48 weeks. Multiparameter FACS analysis was used to examine relative expression of 14 different inhibitory/activating receptors. Interleukin (IL)-28B genotyping (rs12979860) was also performed. Pretreatment levels of inhibitory receptors CD158a, CD158b, and CD158e were higher in patients who demonstrated poor viral decline within the first 28 days of therapy. Higher expression levels of inhibitory receptors NKG2A, CD158b, and CD158e were demonstrable in patients who failed to achieve sustained virologic response (SVR). Patients carrying the IL-28B T allele had higher NKG2A expression on effector NKs. We created a mathematical regression model incorporating race, viral level, and two inhibitory receptors. The area-under-the curve was 0.88, which is highly predictive of SVR. Moreover, the model performed complementarily with IL-28B across the CC, CT, and TT genotypes. Purified NKG2A(neg) NKs treated with pegylated-IFN-α for 4 hours demonstrated higher levels of IFN-γ-inducible protein-10 (IP-10) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) compared with their NKG2A(pos) counterparts. CONCLUSIONS These results provide novel insights into the associations of NK phenotype with IL-28B genotype and gene expression patterns, as well as the role of NKs in mediating IFN-induced viral clearance of chronic HCV infection.
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MESH Headings
- Adult
- Aged
- Antiviral Agents/therapeutic use
- Drug Resistance, Viral/genetics
- Drug Resistance, Viral/immunology
- Female
- Genotype
- Hepatitis C, Chronic/drug therapy
- Hepatitis C, Chronic/genetics
- Hepatitis C, Chronic/immunology
- Humans
- Interferon-alpha/metabolism
- Interferons
- Interleukins/genetics
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Male
- Membrane Proteins/metabolism
- Middle Aged
- Multivariate Analysis
- NK Cell Lectin-Like Receptor Subfamily C/metabolism
- Receptor, Interferon alpha-beta/metabolism
- Receptors, KIR2DL1/metabolism
- Receptors, KIR2DL3/metabolism
- Receptors, KIR3DL1/metabolism
- Receptors, Natural Killer Cell/metabolism
- Treatment Failure
- Young Adult
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Affiliation(s)
- Lucy Golden-Mason
- Division of Gastroenterology & Hepatology, Hepatitis C Center, Department of Medicine, University of Colorado Denver & National Jewish Hospital, Denver CO. USA
- Integrated Program in Immunology; University of Colorado Denver & National Jewish Hospital, Denver CO. USA
| | - Kiran M. Bambha
- Division of Gastroenterology & Hepatology, Hepatitis C Center, Department of Medicine, University of Colorado Denver & National Jewish Hospital, Denver CO. USA
| | - Linling Cheng
- Division of Gastroenterology & Hepatology, Hepatitis C Center, Department of Medicine, University of Colorado Denver & National Jewish Hospital, Denver CO. USA
| | - Charles D. Howell
- University of Maryland Baltimore School of Medicine, Baltimore, MD. USA
| | - Milton W. Taylor
- Department of Biology, Indiana University, Bloomington, IN 47401, USA
| | - Paul J. Clark
- Duke Clinical Research Institute and Division of Gastroenterology, Duke University Medical Center, School of Medicine, Duke University, Durham, NC, USA
| | - Nezam Afdhal
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Hugo R. Rosen
- Division of Gastroenterology & Hepatology, Hepatitis C Center, Department of Medicine, University of Colorado Denver & National Jewish Hospital, Denver CO. USA
- Integrated Program in Immunology; University of Colorado Denver & National Jewish Hospital, Denver CO. USA
- Denver VA Medical Center, Denver, CO, USA
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37
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Dustin ML, Depoil D. New insights into the T cell synapse from single molecule techniques. Nat Rev Immunol 2011; 11:672-84. [PMID: 21904389 DOI: 10.1038/nri3066] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
T cell activation depends on extracellular ligation of the T cell receptor (TCR) by peptide-MHC complexes in a synapse between the T cell and an antigen-presenting cell. The process then requires the assembly of signalling complexes between the TCR and the adaptor protein linker for activation of T cells (LAT), and subsequent filamentous actin (F-actin)-dependent TCR cluster formation. Recent progress in each of these areas, made possible by the emergence of new techniques, has forced us to rethink our assumptions and consider some radical new models. These describe the receptor interaction parameters that control T cell responses and the mechanism by which LAT is recruited to the TCR signalling machinery. This is an exciting time in T cell biology, and further innovation in imaging and genomics is likely to lead to a greater understanding of how T cells are activated.
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Affiliation(s)
- Michael L Dustin
- Helene and Martin Kimmel Center for Biology and Medicine of the Skirball Institute of Biomolecular Medicine, Department of Pathology, New York University School of Medicine, 540 First Avenue, New York, New York 10012, USA.
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38
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Burroughs NJ, Köhler K, Miloserdov V, Dustin ML, van der Merwe PA, Davis DM. Boltzmann energy-based image analysis demonstrates that extracellular domain size differences explain protein segregation at immune synapses. PLoS Comput Biol 2011; 7:e1002076. [PMID: 21829338 PMCID: PMC3150282 DOI: 10.1371/journal.pcbi.1002076] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 04/19/2011] [Indexed: 01/08/2023] Open
Abstract
Immune synapses formed by T and NK cells both show segregation of the integrin ICAM1 from other proteins such as CD2 (T cell) or KIR (NK cell). However, the mechanism by which these proteins segregate remains unclear; one key hypothesis is a redistribution based on protein size. Simulations of this mechanism qualitatively reproduce observed segregation patterns, but only in certain parameter regimes. Verifying that these parameter constraints in fact hold has not been possible to date, this requiring a quantitative coupling of theory to experimental data. Here, we address this challenge, developing a new methodology for analysing and quantifying image data and its integration with biophysical models. Specifically we fit a binding kinetics model to 2 colour fluorescence data for cytoskeleton independent synapses (2 and 3D) and test whether the observed inverse correlation between fluorophores conforms to size dependent exclusion, and further, whether patterned states are predicted when model parameters are estimated on individual synapses. All synapses analysed satisfy these conditions demonstrating that the mechanisms of protein redistribution have identifiable signatures in their spatial patterns. We conclude that energy processes implicit in protein size based segregation can drive the patternation observed in individual synapses, at least for the specific examples tested, such that no additional processes need to be invoked. This implies that biophysical processes within the membrane interface have a crucial impact on cell:cell communication and cell signalling, governing protein interactions and protein aggregation.
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Affiliation(s)
- Nigel J Burroughs
- Systems Biology Centre, University of Warwick, Coventry, United Kingdom.
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39
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Kaplan A, Kotzer S, Almeida CR, Kohen R, Halpert G, Salmon-Divon M, Köhler K, Höglund P, Davis DM, Mehr R. Simulations of the NK cell immune synapse reveal that activation thresholds can be established by inhibitory receptors acting locally. THE JOURNAL OF IMMUNOLOGY 2011; 187:760-73. [PMID: 21690326 DOI: 10.4049/jimmunol.1002208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cell activation is regulated by a balance between activating and inhibitory signals. To address the question of how these signals are spatially integrated, we created a computer simulation of activating and inhibitory NK cell immunological synapse (NKIS) assembly, implementing either a "quantity-based" inhibition model or a "distance-based" inhibition model. The simulations mimicked the observed molecule distributions in inhibitory and activating NKIS and yielded several new insights. First, the total signal is highly influenced by activating complex dissociation rates but not by adhesion and inhibitory complex dissociation rates. Second, concerted motion of receptors in clusters significantly accelerates NKIS maturation. Third, when the potential of a cis interaction between Ly49 receptors and MHC class I on murine NK cells was added to the model, the integrated signal as a function of receptor and ligand numbers was only slightly increased, at least up to the level of 50% cis-bound Ly49 receptors reached in the model. Fourth, and perhaps most importantly, the integrated signal behavior obtained when using the distance-based inhibition signal model was closer to the experimentally observed behavior, with an inhibition radius of the order 3-10 molecules. Microscopy to visualize Vav activation in NK cells on micropatterned surfaces of activating and inhibitory strips revealed that Vav is only locally activated where activating receptors are ligated within a single NK cell contact. Taken together, these data are consistent with a model in which inhibitory receptors act locally; that is, that every bound inhibitory receptor acts on activating receptors within a certain radius around it.
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Affiliation(s)
- Asya Kaplan
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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