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Dam T, Chouliara M, Junghans V, Jönsson P. Supported Lipid Bilayers and the Study of Two-Dimensional Binding Kinetics. Front Mol Biosci 2022; 9:833123. [PMID: 35252352 PMCID: PMC8896763 DOI: 10.3389/fmolb.2022.833123] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
Binding between protein molecules on contacting cells is essential in initiating and regulating several key biological processes. In contrast to interactions between molecules in solution, these events are restricted to the two-dimensional (2D) plane of the meeting cell surfaces. However, converting between the more commonly available binding kinetics measured in solution and the so-called 2D binding kinetics has proven a complicated task since for the latter several factors other than the protein-protein interaction per se have an impact. A few important examples of these are: protein density, membrane fluctuations, force on the bond and the use of auxiliary binding molecules. The development of model membranes, and in particular supported lipid bilayers (SLBs), has made it possible to simplify the studied contact to analyze these effects and to measure 2D binding kinetics of individual protein-protein interactions. We will in this review give an overview of, and discuss, how different SLB systems have been used for this and compare different methods to measure binding kinetics in cell-SLB contacts. Typically, the SLB is functionalized with fluorescently labelled ligands whose interaction with the corresponding receptor on a binding cell can be detected. This interaction can either be studied 1) by an accumulation of ligands in the cell-SLB contact, whose magnitude depends on the density of the proteins and binding affinity of the interaction, or 2) by tracking single ligands in the SLB, which upon interaction with a receptor result in a change of motion of the diffusing ligand. The advantages and disadvantages of other methods measuring 2D binding kinetics will also be discussed and compared to the fluorescence-based methods. Although binding kinetic measurements in cell-SLB contacts have provided novel information on how ligands interact with receptors in vivo the number of these measurements is still limited. This is influenced by the complexity of the system as well as the required experimental time. Moreover, the outcome can vary significantly between studies, highlighting the necessity for continued development of methods to study 2D binding kinetics with higher precision and ease.
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Affiliation(s)
- Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | | | - Victoria Junghans
- Nuffield Department of Medicine, CAMS Oxford Institute, University of Oxford, Oxford, United Kingdom
| | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
- *Correspondence: Peter Jönsson,
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2
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Sun L, Gang X, Li Z, Zhao X, Zhou T, Zhang S, Wang G. Advances in Understanding the Roles of CD244 (SLAMF4) in Immune Regulation and Associated Diseases. Front Immunol 2021; 12:648182. [PMID: 33841431 PMCID: PMC8024546 DOI: 10.3389/fimmu.2021.648182] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/24/2021] [Indexed: 12/16/2022] Open
Abstract
Proteins in the signaling lymphocytic activating molecule (SLAM) family play crucial roles in regulating the immune system. CD244 (SLAMF4) is a protein in this family, and is also a member of the CD2 subset of the immunoglobulin (Ig) superfamily. CD244 is a cell surface protein expressed by NK cells, T cells, monocytes, eosinophils, myeloid-derived suppressor cells, and dendritic cells. CD244 binds to the ligand CD48 on adjacent cells and transmits stimulatory or inhibitory signals that regulate immune function. In-depth studies reported that CD244 functions in many immune-related diseases, such as autoimmune diseases, infectious diseases, and cancers, and its action is essential for the onset and progression of these diseases. The discovery of these essential roles of CD244 suggests it has potential as a prognostic indicator or therapeutic target. This review describes the molecular structure and function of CD244 and its roles in various immune cells and immune-related diseases.
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Affiliation(s)
| | | | | | | | | | | | - Guixia Wang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
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3
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Bao YJ, Qiu J, Luo Y, Rodríguez F, Qiu HJ. The genetic variation landscape of African swine fever virus reveals frequent positive selection and adaptive flexibility. Transbound Emerg Dis 2021; 68:2703-2721. [PMID: 33751854 DOI: 10.1111/tbed.14018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 02/01/2021] [Indexed: 12/14/2022]
Abstract
African swine fever virus (ASFV) is a lethal disease agent that causes high mortality in swine population and devastating loss in swine industries. The development of efficacious vaccines has been hindered by the gap in knowledge concerning genetic variation of ASFV and the genetic factors involved in host adaptation and virus-host interactions. In this study, we performed a meta-genetic study of ASFV aiming to profile the variation landscape and identify genetic factors with signatures of positive selection and relevance to host adaptation. Our data reveal a high level of genetic variability of ASFV shaped by both diversifying selection and selective sweep. The selection signatures are widely distributed across the genome with the diversifying selection falling within 29 genes and selection sweep within 25 genes, highlighting strong signals of adaptive evolution of ASFV. Further examination of the sequence properties reveals the link of the selection signatures with virus-host interactions and adaptive flexibility. Specifically, we discovered a site at 157th of the key antigen protein EP402R under diversifying selection, which is located in the cytotoxic T-cell epitope related to the low level of cross-reaction in T-cell response. Importantly, two multigene families MGF360 and MGF505, the host range factors of ASFV, exhibit divergent selection among the paralogous members, conferring sequence pools for genetic diversification and adaptive capability. By integrating the genes with selection signatures into a unified framework of interactions between ASFV and hosts, we showed that the genes are involved in multiple processes of host immune interaction and virus life cycles, and may play crucial roles in circumventing host defence systems and enhancing adaptive fitness. Our findings will allow enhanced understanding of genetic basis of rapid spreading and adaptation of ASFV among the hosts.
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Affiliation(s)
- Yun-Juan Bao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Junhui Qiu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
| | - Fernando Rodríguez
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Universitat Autonòma de Barcelona, Bellaterra, 08193, Spain
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China
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4
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Junghans V, Chouliara M, Santos AM, Hatherley D, Petersen J, Dam T, Svensson LM, Rossjohn J, Davis SJ, Jönsson P. Effects of a local auxiliary protein on the two-dimensional affinity of a TCR-peptide MHC interaction. J Cell Sci 2020; 133:jcs245985. [PMID: 32591485 DOI: 10.1242/jcs.245985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
The affinity of T-cell receptors (TCRs) for major histocompatibility complex molecules (MHCs) presenting cognate antigens likely determines whether T cells initiate immune responses, or not. There exist few measurements of two-dimensional (2D) TCR-MHC interactions, and the effect of auxiliary proteins on binding is unexplored. Here, Jurkat T-cells expressing the MHC molecule HLA-DQ8-glia-α1 and the ligand of an adhesion protein (rat CD2) were allowed to bind supported lipid bilayers (SLBs) presenting fluorescently labelled L3-12 TCR and rat CD2, allowing measurements of binding unconfounded by cell signaling effects or co-receptor binding. The 2D Kd for L3-12 TCR binding to HLA-DQ8-glia-α1, of 14±5 molecules/μm2 (mean±s.d.), was only marginally influenced by including CD2 up to ∼200 bound molecules/μm2 but higher CD2 densities reduced the affinity up to 1.9-fold. Cell-SLB contact size increased steadily with ligand density without affecting binding for contacts at up to ∼20% of total cell area, but beyond this lamellipodia appeared, giving an apparent increase in bound receptors of up to 50%. Our findings show how parameters other than the specific protein-protein interaction can influence binding behavior at cell-cell contacts.
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Affiliation(s)
| | - Manto Chouliara
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
| | - Ana Mafalda Santos
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Deborah Hatherley
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Jan Petersen
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Tommy Dam
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
| | - Lena M Svensson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; and School of Medical Sciences, Örebro University, 701 82 Örebro, Sweden
| | - Jamie Rossjohn
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
- Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Simon J Davis
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Peter Jönsson
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
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5
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Dong L, Yuan C, Orlando BJ, Malkowski MG, Smith WL. Fatty Acid Binding to the Allosteric Subunit of Cyclooxygenase-2 Relieves a Tonic Inhibition of the Catalytic Subunit. J Biol Chem 2016; 291:25641-25655. [PMID: 27756840 DOI: 10.1074/jbc.m116.757310] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/13/2016] [Indexed: 01/24/2023] Open
Abstract
Prostaglandin endoperoxide H synthase-2 (PGHS-2), also called cyclooxygenase-2 (COX-2), converts arachidonic acid to PGH2 PGHS-2 is a conformational heterodimer composed of allosteric (Eallo) and catalytic (Ecat) subunits. Fatty acids (FAs) bind to Arg-120 of Eallo increasing to different degrees, depending on the FA, the Vmax of its Ecat partner. We report here that movement of helical residues 120-122 and loop residues 123-129 of Eallo underlies the allosteric effects of FAs and allosteric COX-2 inhibitors, including naproxen and flurbiprofen. An S121P substitution in both PGHS-2 monomers yields a variant (S121P/S121P PGHS-2) that has 1.7-1.8 times the Vmax of native PGHS-2 and is relatively insensitive to activation by FAs or inhibition by allosteric inhibitors. The S121P substitution in Eallo is primarily responsible for these effects. In X-ray crystal structures, the Cα atoms of helical residues 119-122 of S121P/S121P PGHS-2 are displaced from their normal positions. Additionally, the S121P/S121P PGHS-2 variants in which Pro-127 and Ser-541 are replaced by cysteines spontaneously forms Cys-127 to Cys-541 cross-links between monomers. This is unlike the corresponding native PGHS-2 variant and suggests that S121P substitutions also unhinge the loop involving residues 123-129. We conclude the following: (a) the region involving residues 120-129 of unoccupied Eallo tonically inhibits Ecat; (b) binding of an activating FA (e.g. arachidonic, palmitic, or oleic acid) to Eallo or an S121P substitution in Eallo repositions this region to increase Ecat activity; and (c) allosteric COX inhibitors act by preventing FA binding to Eallo and additionally by relocating Eallo residues to inhibit Ecat.
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Affiliation(s)
- Liang Dong
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Chong Yuan
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Benjamin J Orlando
- the Department of Structural Biology, University at Buffalo, The State University of New York, and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
| | - Michael G Malkowski
- the Department of Structural Biology, University at Buffalo, The State University of New York, and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
| | - William L Smith
- From the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
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6
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Chang VT, Fernandes RA, Ganzinger KA, Lee SF, Siebold C, McColl J, Jönsson P, Palayret M, Harlos K, Coles CH, Jones EY, Lui Y, Huang E, Gilbert RJC, Klenerman D, Aricescu AR, Davis SJ. Initiation of T cell signaling by CD45 segregation at 'close contacts'. Nat Immunol 2016; 17:574-582. [PMID: 26998761 PMCID: PMC4839504 DOI: 10.1038/ni.3392] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/29/2015] [Indexed: 12/14/2022]
Abstract
It has been proposed that the local segregation of kinases and the tyrosine phosphatase CD45 underpins T cell antigen receptor (TCR) triggering, but how such segregation occurs and whether it can initiate signaling is unclear. Using structural and biophysical analysis, we show that the extracellular region of CD45 is rigid and extends beyond the distance spanned by TCR-ligand complexes, implying that sites of TCR-ligand engagement would sterically exclude CD45. We also show that the formation of 'close contacts', new structures characterized by spontaneous CD45 and kinase segregation at the submicron-scale, initiates signaling even when TCR ligands are absent. Our work reveals the structural basis for, and the potent signaling effects of, local CD45 and kinase segregation. TCR ligands have the potential to heighten signaling simply by holding receptors in close contacts.
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Affiliation(s)
- Veronica T Chang
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Ricardo A Fernandes
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | | | - Steven F Lee
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - James McColl
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Peter Jönsson
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Matthieu Palayret
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Charlotte H Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Yuan Lui
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Elizabeth Huang
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Simon J Davis
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
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7
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Remarkably low affinity of CD4/peptide-major histocompatibility complex class II protein interactions. Proc Natl Acad Sci U S A 2016; 113:5682-7. [PMID: 27114505 DOI: 10.1073/pnas.1513918113] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The αβ T-cell coreceptor CD4 enhances immune responses more than 1 million-fold in some assays, and yet the affinity of CD4 for its ligand, peptide-major histocompatibility class II (pMHC II) on antigen-presenting cells, is so weak that it was previously unquantifiable. Here, we report that a soluble form of CD4 failed to bind detectably to pMHC II in surface plasmon resonance-based assays, establishing a new upper limit for the solution affinity at 2.5 mM. However, when presented multivalently on magnetic beads, soluble CD4 bound pMHC II-expressing B cells, confirming that it is active and allowing mapping of the native coreceptor binding site on pMHC II. Whereas binding was undetectable in solution, the affinity of the CD4/pMHC II interaction could be measured in 2D using CD4- and adhesion molecule-functionalized, supported lipid bilayers, yielding a 2D Kd of ∼5,000 molecules/μm(2) This value is two to three orders of magnitude higher than previously measured 2D Kd values for interacting leukocyte surface proteins. Calculations indicated, however, that CD4/pMHC II binding would increase rates of T-cell receptor (TCR) complex phosphorylation by threefold via the recruitment of Lck, with only a small, 2-20% increase in the effective affinity of the TCR for pMHC II. The affinity of CD4/pMHC II therefore seems to be set at a value that increases T-cell sensitivity by enhancing phosphorylation, without compromising ligand discrimination.
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8
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Chang VT, Spooner RA, Crispin M, Davis SJ. Glycan Remodeling with Processing Inhibitors and Lectin-Resistant Eukaryotic Cells. Methods Mol Biol 2016; 1321:307-22. [PMID: 26082231 DOI: 10.1007/978-1-4939-2760-9_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Some of the most important and interesting molecules in metazoan biology are glycoproteins. The importance of the carbohydrate component of these structures is often revealed by the disease phenotypes that manifest when the biosynthesis of particular glycoforms is disrupted. On the other hand, the presence of large amounts of carbohydrate can often hinder the structural and functional analysis of glycoproteins. There are often good reasons, therefore, for wanting to engineer and predefine the N-glycans present on glycoproteins, e.g., in order to characterize the functions of the glycans or facilitate their subsequent removal. Here, we describe in detail two distinct ways in which to usefully interfere with oligosaccharide processing, one involving the use of specific processing inhibitors, and the other the selection of cell lines mutated at gene loci that control oligosaccharide processing, using cytotoxic lectins. Both approaches have the capacity for controlled, radical alteration of oligosaccharide processing in eukaryotic cells used for heterologous protein expression, and have great utility in the structural analysis of glycoproteins.
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Affiliation(s)
- Veronica T Chang
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, UK
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9
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McArdel SL, Terhorst C, Sharpe AH. Roles of CD48 in regulating immunity and tolerance. Clin Immunol 2016; 164:10-20. [PMID: 26794910 DOI: 10.1016/j.clim.2016.01.008] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/14/2016] [Accepted: 01/16/2016] [Indexed: 12/15/2022]
Abstract
CD48, a member of the signaling lymphocyte activation molecule family, participates in adhesion and activation of immune cells. Although constitutively expressed on most hematopoietic cells, CD48 is upregulated on subsets of activated cells. CD48 can have activating roles on T cells, antigen presenting cells and granulocytes, by binding to CD2 or bacterial FimH, and through cell intrinsic effects. Interactions between CD48 and its high affinity ligand CD244 are more complex, with both stimulatory and inhibitory outcomes. CD244:CD48 interactions regulate target cell lysis by NK cells and CTLs, which are important for viral clearance and regulation of effector/memory T cell generation and survival. Here we review roles of CD48 in infection, tolerance, autoimmunity, and allergy, as well as the tools used to investigate this receptor. We discuss stimulatory and regulatory roles for CD48, its potential as a therapeutic target in human disease, and current challenges to investigation of this immunoregulatory receptor.
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Affiliation(s)
- Shannon L McArdel
- Department of Microbiology and Immunobiology, Evergrande Center for Immunologic Diseases, Harvard Medical School, Boston, MA, USA
| | - Cox Terhorst
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Arlene H Sharpe
- Department of Microbiology and Immunobiology, Evergrande Center for Immunologic Diseases, Harvard Medical School, Boston, MA, USA.
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10
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Rohr J, Guo S, Huo J, Bouska A, Lachel C, Li Y, Simone PD, Zhang W, Gong Q, Wang C, Cannon A, Heavican T, Mottok A, Hung S, Rosenwald A, Gascoyne R, Fu K, Greiner TC, Weisenburger DD, Vose JM, Staudt LM, Xiao W, Borgstahl GEO, Davis S, Steidl C, McKeithan T, Iqbal J, Chan WC. Recurrent activating mutations of CD28 in peripheral T-cell lymphomas. Leukemia 2015; 30:1062-70. [PMID: 26719098 DOI: 10.1038/leu.2015.357] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/30/2015] [Accepted: 12/15/2015] [Indexed: 11/09/2022]
Abstract
Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of mature T-cell neoplasms with a poor prognosis. Recently, mutations in TET2 and other epigenetic modifiers as well as RHOA have been identified in these diseases, particularly in angioimmunoblastic T-cell lymphoma (AITL). CD28 is the major co-stimulatory receptor in T cells which, upon binding ligand, induces sustained T-cell proliferation and cytokine production when combined with T-cell receptor stimulation. We have identified recurrent mutations in CD28 in PTCLs. Two residues-D124 and T195-were recurrently mutated in 11.3% of cases of AITL and in one case of PTCL, not otherwise specified (PTCL-NOS). Surface plasmon resonance analysis of mutations at these residues with predicted differential partner interactions showed increased affinity for ligand CD86 (residue D124) and increased affinity for intracellular adaptor proteins GRB2 and GADS/GRAP2 (residue T195). Molecular modeling studies on each of these mutations suggested how these mutants result in increased affinities. We found increased transcription of the CD28-responsive genes CD226 and TNFA in cells expressing the T195P mutant in response to CD3 and CD86 co-stimulation and increased downstream activation of NF-κB by both D124V and T195P mutants, suggesting a potential therapeutic target in CD28-mutated PTCLs.
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Affiliation(s)
- J Rohr
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
| | - S Guo
- Department of Pathology, Xi Jing Hospital, Fourth Military Medical University, Xi'an, Shaan Xi Province, China
| | - J Huo
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - A Bouska
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - C Lachel
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Y Li
- Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
| | - P D Simone
- Internal Medicine Residency Program, Florida Atlantic University College of Medicine, Boca Raton, FL, USA
| | - W Zhang
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Q Gong
- Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
| | - C Wang
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA.,School of Medicine, Shandong University, Jinan, China
| | - A Cannon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - T Heavican
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - A Mottok
- Department for Lymphoid Cancer Research, Centre for Lymphoid Cancer, BC Cancer Agency, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - S Hung
- Department for Lymphoid Cancer Research, Centre for Lymphoid Cancer, BC Cancer Agency, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - A Rosenwald
- Institute of Pathology and Comprehensive Cancer Center Mainfranken (CCC MF), University of Wuerzburg, Wuerzburg, Germany
| | - R Gascoyne
- Department for Lymphoid Cancer Research, Centre for Lymphoid Cancer, BC Cancer Agency, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - K Fu
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - T C Greiner
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - D D Weisenburger
- Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
| | - J M Vose
- Department of Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - L M Staudt
- National Institutes of Health, Bethesda, MD, USA
| | - W Xiao
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, Food and Drug Administration, Washington, DC, USA
| | - G E O Borgstahl
- Eppley Institute for Cancer Research and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - S Davis
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - C Steidl
- Department for Lymphoid Cancer Research, Centre for Lymphoid Cancer, BC Cancer Agency, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - T McKeithan
- Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
| | - J Iqbal
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - W C Chan
- Department of Pathology, City of Hope National Medical Center, Duarte, CA, USA
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11
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Taylor EB, Wilson M, Bengten E. The Src tyrosine kinase Lck binds to CD2, CD4-1, and CD4-2 T cell co-receptors in channel catfish, Ictalurus punctatus. Mol Immunol 2015; 66:126-38. [DOI: 10.1016/j.molimm.2015.02.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 02/19/2015] [Accepted: 02/19/2015] [Indexed: 10/23/2022]
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12
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Wang X, Ji CG, Zhang JZH. Glycosylation Modulates Human CD2-CD58 Adhesion via Conformational Adjustment. J Phys Chem B 2015; 119:6493-501. [PMID: 25984915 DOI: 10.1021/jp509949b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human CD2 is a transmembrane cell surface glycoprotein found on T lymphocytes and natural killer cells and plays important roles in immune recognition. The interaction between human CD2 and its counter receptor CD58 facilitates surface adhesion between helper T lymphocytes and antigen presenting cells as well as between cytolytic effectors and target cells. In this study, the molecular effect of glycosylation of CD2 on the structure and dynamics of the CD2-CD58 adhesion complex were examined via MD simulation to help understand the fundamental mechanism of glycosylation that controls CD2-CD58 adhesion. The present result and detailed analysis revealed that the binding interaction of human CD2-CD58 is dominated by three hot spots that form a binding triangle whose topology is critical for stable binding of CD2-CD58. Our study found that the conformation of human CD2, represented by the topology of this binding triangle, is significantly adjusted and steered by glycosylation toward a particular conformation that energetically stabilizes the CD2-CD58 complex. Thus, the fundamental mechanism of glycosylation of human CD2 is to promote CD2-CD58 binding by conformational adjustment of CD2. The current result and explanation are in excellent agreement with previous experiments and help elucidate the dynamical mechanism of glycosylation of human CD2.
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Affiliation(s)
- Xingyu Wang
- §NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - Chang G Ji
- †Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engeineering, East China Normal University, Shanghai 200062, China.,‡State Key Laboratory of Precision Spectroscopy, Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062, China.,§NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - John Z H Zhang
- †Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engeineering, East China Normal University, Shanghai 200062, China.,‡State Key Laboratory of Precision Spectroscopy, Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062, China.,§NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China.,∥Department of Chemistry, New York University, New York, New York 10003, United States
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13
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Cheng X, Veverka V, Radhakrishnan A, Waters LC, Muskett FW, Morgan SH, Huo J, Yu C, Evans EJ, Leslie AJ, Griffiths M, Stubberfield C, Griffin R, Henry AJ, Jansson A, Ladbury JE, Ikemizu S, Carr MD, Davis SJ. Structure and interactions of the human programmed cell death 1 receptor. J Biol Chem 2013; 288:11771-85. [PMID: 23417675 PMCID: PMC3636866 DOI: 10.1074/jbc.m112.448126] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
PD-1, a receptor expressed by T cells, B cells, and monocytes, is a potent regulator of immune responses and a promising therapeutic target. The structure and interactions of human PD-1 are, however, incompletely characterized. We present the solution nuclear magnetic resonance (NMR)-based structure of the human PD-1 extracellular region and detailed analyses of its interactions with its ligands, PD-L1 and PD-L2. PD-1 has typical immunoglobulin superfamily topology but differs at the edge of the GFCC′ sheet, which is flexible and completely lacks a C″ strand. Changes in PD-1 backbone NMR signals induced by ligand binding suggest that, whereas binding is centered on the GFCC′ sheet, PD-1 is engaged by its two ligands differently and in ways incompletely explained by crystal structures of mouse PD-1·ligand complexes. The affinities of these interactions and that of PD-L1 with the costimulatory protein B7-1, measured using surface plasmon resonance, are significantly weaker than expected. The 3–4-fold greater affinity of PD-L2 versus PD-L1 for human PD-1 is principally due to the 3-fold smaller dissociation rate for PD-L2 binding. Isothermal titration calorimetry revealed that the PD-1/PD-L1 interaction is entropically driven, whereas PD-1/PD-L2 binding has a large enthalpic component. Mathematical simulations based on the biophysical data and quantitative expression data suggest an unexpectedly limited contribution of PD-L2 to PD-1 ligation during interactions of activated T cells with antigen-presenting cells. These findings provide a rigorous structural and biophysical framework for interpreting the important functions of PD-1 and reveal that potent inhibitory signaling can be initiated by weakly interacting receptors.
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Affiliation(s)
- Xiaoxiao Cheng
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
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14
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Nagae M, Yamaguchi Y. Function and 3D structure of the N-glycans on glycoproteins. Int J Mol Sci 2012; 13:8398-8429. [PMID: 22942711 PMCID: PMC3430242 DOI: 10.3390/ijms13078398] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 06/28/2012] [Accepted: 06/18/2012] [Indexed: 12/17/2022] Open
Abstract
Glycosylation is one of the most common post-translational modifications in eukaryotic cells and plays important roles in many biological processes, such as the immune response and protein quality control systems. It has been notoriously difficult to study glycoproteins by X-ray crystallography since the glycan moieties usually have a heterogeneous chemical structure and conformation, and are often mobile. Nonetheless, recent technical advances in glycoprotein crystallography have accelerated the accumulation of 3D structural information. Statistical analysis of “snapshots” of glycoproteins can provide clues to understanding their structural and dynamic aspects. In this review, we provide an overview of crystallographic analyses of glycoproteins, in which electron density of the glycan moiety is clearly observed. These well-defined N-glycan structures are in most cases attributed to carbohydrate-protein and/or carbohydrate-carbohydrate interactions and may function as “molecular glue” to help stabilize inter- and intra-molecular interactions. However, the more mobile N-glycans on cell surface receptors, the electron density of which is usually missing on X-ray crystallography, seem to guide the partner ligand to its binding site and prevent irregular protein aggregation by covering oligomerization sites away from the ligand-binding site.
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Affiliation(s)
| | - Yoshiki Yamaguchi
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-48-467-9619; Fax: +81-48-467-9620
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15
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Fernandes RA, Shore DA, Vuong MT, Yu C, Zhu X, Pereira-Lopes S, Brouwer H, Fennelly JA, Jessup CM, Evans EJ, Wilson IA, Davis SJ. T cell receptors are structures capable of initiating signaling in the absence of large conformational rearrangements. J Biol Chem 2012; 287:13324-35. [PMID: 22262845 PMCID: PMC3339974 DOI: 10.1074/jbc.m111.332783] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/10/2012] [Indexed: 12/18/2022] Open
Abstract
Native and non-native ligands of the T cell receptor (TCR), including antibodies, have been proposed to induce signaling in T cells via intra- or intersubunit conformational rearrangements within the extracellular regions of TCR complexes. We have investigated whether any signatures can be found for such postulated structural changes during TCR triggering induced by antibodies, using crystallographic and mutagenesis-based approaches. The crystal structure of murine CD3ε complexed with the mitogenic anti-CD3ε antibody 2C11 enabled the first direct structural comparisons of antibody-liganded and unliganded forms of CD3ε from a single species, which revealed that antibody binding does not induce any substantial rearrangements within CD3ε. Saturation mutagenesis of surface-exposed CD3ε residues, coupled with assays of antibody-induced signaling by the mutated complexes, suggests a new configuration for the complex within which CD3ε is highly exposed and reveals that no large new CD3ε interfaces are required to form during antibody-induced signaling. The TCR complex therefore appears to be a structure that is capable of initiating intracellular signaling in T cells without substantial structural rearrangements within or between the component subunits. Our findings raise the possibility that signaling by native ligands might also be initiated in the absence of large structural rearrangements in the receptor.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- CD3 Complex/chemistry
- CD3 Complex/genetics
- CD3 Complex/immunology
- Crystallography, X-Ray
- Dimerization
- Epitopes, T-Lymphocyte/immunology
- Humans
- Immunoglobulin Fab Fragments/immunology
- Jurkat Cells
- Mice
- Mutagenesis, Site-Directed
- Protein Conformation
- Protein Structure, Tertiary
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction/immunology
- Structure-Activity Relationship
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Affiliation(s)
- Ricardo A. Fernandes
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - David A. Shore
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Mai T. Vuong
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Chao Yu
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Xueyong Zhu
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Selma Pereira-Lopes
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Heather Brouwer
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Janet A. Fennelly
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Claire M. Jessup
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Edward J. Evans
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
| | - Ian A. Wilson
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Simon J. Davis
- From the Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom and
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16
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Structure of the measles virus hemagglutinin bound to its cellular receptor SLAM. Nat Struct Mol Biol 2011; 18:135-41. [DOI: 10.1038/nsmb.1969] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 10/29/2010] [Indexed: 12/26/2022]
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17
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Wright GJ. Signal initiation in biological systems: the properties and detection of transient extracellular protein interactions. MOLECULAR BIOSYSTEMS 2010; 5:1405-12. [PMID: 19593473 PMCID: PMC2898632 DOI: 10.1039/b903580j] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Extracellular glycoprotein interactions are not detected by most high throughput assays creating “blind-spots” in protein interaction maps. This review examines this problem and discusses recent advances that have begun to address it.
Individual cells within biological systems frequently coordinate their functions through signals initiated by specific extracellular protein interactions involving receptors that bridge the cellular membrane. Due to their biochemical nature, these membrane-embedded receptor proteins are difficult to manipulate and their interactions are characterised by very weak binding strengths that cannot be detected using popular high throughput assays. This review will provide a general outline of the biochemical attributes of receptor proteins focussing in particular on the biophysical properties of their transient interactions. Methods that are able to detect these weak extracellular binding events and especially those that can be used for identifying novel interactions will be compared. Finally, I discuss the feasibility of constructing a complete and accurate extracellular protein interaction map, and the methods that are likely to be useful in achieving this goal.
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Affiliation(s)
- Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK.
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18
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Recent advances in the production of proteins in insect and mammalian cells for structural biology. J Struct Biol 2010; 172:55-65. [PMID: 20153433 DOI: 10.1016/j.jsb.2010.02.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 02/04/2010] [Accepted: 02/07/2010] [Indexed: 11/22/2022]
Abstract
The production of proteins in sufficient quantity and of appropriate quality is an essential pre-requisite for structural studies. Escherichia coli remains the dominant expression system in structural biology with nearly 90% of the structures in the Protein Data Bank (PDB) derived from proteins produced in this bacterial host. However, many mammalian and eukaryotic viral proteins require post-translation modification for proper folding and/or are part of large multimeric complexes. Therefore expression in higher eukaryotic cell lines from both invertebrate and vertebrate is required to produce these proteins. Although these systems are generally more time-consuming and expensive to use than bacteria, there have been improvements in technology that have streamlined the processes involved. For example, the use of multi-host vectors, i.e., containing promoters for not only E. coli but also mammalian and baculovirus expression in insect cells, enables target genes to be evaluated in both bacterial and higher eukaryotic hosts from a single vector. Culturing cells in micro-plate format allows screening of large numbers of vectors in parallel and is amenable to automation. The development of large-scale transient expression in mammalian cells offers a way of rapidly producing proteins with relatively high throughput. Strategies for selenomethionine-labelling (important for obtaining phase information in crystallography) and controlling glycosylation (important for reducing the chemical heterogeneity of glycoproteins) have also been reported for higher eukaryotic cell expression systems.
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19
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Calpe S, Wang N, Romero X, Berger SB, Lanyi A, Engel P, Terhorst C. The SLAM and SAP gene families control innate and adaptive immune responses. Adv Immunol 2008; 97:177-250. [PMID: 18501771 DOI: 10.1016/s0065-2776(08)00004-7] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The nine SLAM-family genes, SLAMF1-9, a subfamily of the immunoglobulin superfamily, encode differentially expressed cell-surface receptors of hematopoietic cells. Engagement with their ligands, which are predominantly homotypic, leads to distinct signal transduction events, for instance those that occur in the T or NK cell immune synapse. Upon phosphorylation of one or more copies of a unique tyrosine-based signaling motif in their cytoplasmic tails, six of the SLAM receptors recruit the highly specific single SH2-domain adapters SLAM-associated protein (SAP), EAT-2A, and/or EAT-2B. These adapters in turn bind to the tyrosine kinase Fyn and/or other protein tyrosine kinases connecting the receptors to signal transduction networks. Individuals deficient in the SAP gene, SH2D1A, develop an immunodeficiency syndrome: X-linked lympho-proliferative disease. In addition to operating in the immune synapse, SLAM receptors initiate or partake in multiple effector functions of hematopoietic cells, for example, neutrophil and macrophage killing and platelet aggregation. Here we discuss the current understanding of the structure and function of these recently discovered receptors and adapter molecules in the regulation of adaptive and innate immune responses.
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Affiliation(s)
- Silvia Calpe
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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20
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Nunes RJ, Castro MAA, Gonçalves CM, Bamberger M, Pereira CF, Bismuth G, Carmo AM. Protein interactions between CD2 and Lck are required for the lipid raft distribution of CD2. THE JOURNAL OF IMMUNOLOGY 2008; 180:988-97. [PMID: 18178839 DOI: 10.4049/jimmunol.180.2.988] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In T lymphocytes, lipid rafts are preferred sites for signal transduction initiation and amplification. Many cell membrane receptors, such as the TCR, coreceptors, and accessory molecules associate within these microdomains upon cell activation. However, it is still unclear in most cases whether these receptors interact with rafts through lipid-based amino acid modifications or whether raft insertion is driven by protein-protein interactions. In murine T cells, a significant fraction of CD2 associates with membrane lipid rafts. We have addressed the mechanisms that control the localization of rat CD2 at the plasma membrane, and its redistribution within lipid rafts induced upon activation. Following incubation of rat CD2-expressing cells with radioactive-labeled palmitic acid, or using CD2 mutants with Cys226 and Cys228 replaced by alanine residues, we found no evidence that rat CD2 was subjected to lipid modifications that could favor the translocation to lipid rafts, discarding palmitoylation as the principal mechanism for raft addressing. In contrast, using Jurkat cells expressing different CD2 and Lck mutants, we show that the association of CD2 with the rafts fully correlates with CD2 capacity to bind to Lck. As CD2 physically interacts with both Lck and Fyn, preferentially inside lipid rafts, and reflecting the increase of CD2 in lipid rafts following activation, CD2 can mediate the interaction between the two kinases and the consequent boost in kinase activity in lipid rafts.
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Affiliation(s)
- Raquel J Nunes
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
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21
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Okhrimenko O, Jelesarov I. A survey of the year 2006 literature on applications of isothermal titration calorimetry. J Mol Recognit 2008; 21:1-19. [DOI: 10.1002/jmr.859] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Korotkova N, Yang Y, Le Trong I, Cota E, Demeler B, Marchant J, Thomas WE, Stenkamp RE, Moseley SL, Matthews S. Binding of Dr adhesins of Escherichia coli to carcinoembryonic antigen triggers receptor dissociation. Mol Microbiol 2007; 67:420-34. [PMID: 18086185 DOI: 10.1111/j.1365-2958.2007.06054.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carcinoembryonic antigen (CEA)-related cell adhesion molecules (CEACAMs) are host receptors for the Dr family of adhesins of Escherichia coli. To define the mechanism for binding of Dr adhesins to CEACAM receptors, we carried out structural studies on the N-terminal domain of CEA and its complex with the Dr adhesin. The crystal structure of CEA reveals a dimer similar to other dimers formed by receptors with IgV-like domains. The structure of the CEA/Dr adhesin complex is proposed based on NMR spectroscopy and mutagenesis data in combination with biochemical characterization. The Dr adhesin/CEA interface overlaps appreciably with the region responsible for CEA dimerization. Binding kinetics, mutational analysis and spectroscopic examination of CEA dimers suggest that Dr adhesins can dissociate CEA dimers prior to the binding of monomeric forms. Our conclusions include a plausible mechanism for how E. coli, and perhaps other bacterial and viral pathogens, exploit CEACAMs. The present structure of the complex provides a powerful tool for the design of novel inhibitory strategies to treat E. coli infections.
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Affiliation(s)
- Natalia Korotkova
- Department of Microbiology, University of Washington, Seattle, WA 98195-7242, USA
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23
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Aricescu AR, Jones EY. Immunoglobulin superfamily cell adhesion molecules: zippers and signals. Curr Opin Cell Biol 2007; 19:543-50. [PMID: 17935964 DOI: 10.1016/j.ceb.2007.09.010] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 09/14/2007] [Accepted: 09/14/2007] [Indexed: 11/17/2022]
Abstract
The latest structural studies of immunoglobulin superfamily cell adhesion molecules are driving a shift in perspective; increasingly the view is not focused solely on the individual molecule but rather is on the molecular assembly. Two common themes are emerging, revealing mechanisms for ectodomain-dependent regulation of cell surface receptors' signalling abilities. The first is the propensity of many such molecules to arrange in zipper-type or array-type assemblies driven by a network of highly specific cis and trans interactions. The second is the use of the extracellular dimensions of a molecule or adhesion complex as properties which, in combination with characteristic intercellular spacings, can determine the co-localisation or exclusion of particular protein populations at cell interfaces and junctions.
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Affiliation(s)
- A Radu Aricescu
- Cancer Research UK Receptor Structure Research Group, Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Headington, Oxford OX3 7BN, UK
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24
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Velikovsky CA, Deng L, Chlewicki LK, Fernández MM, Kumar V, Mariuzza RA. Structure of natural killer receptor 2B4 bound to CD48 reveals basis for heterophilic recognition in signaling lymphocyte activation molecule family. Immunity 2007; 27:572-84. [PMID: 17950006 DOI: 10.1016/j.immuni.2007.08.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 08/09/2007] [Accepted: 08/10/2007] [Indexed: 12/11/2022]
Abstract
Natural killer (NK) cells eliminate virally infected and tumor cells. Among the receptors regulating NK cell function is 2B4 (CD244), a member of the signaling lymphocyte-activation molecule (SLAM) family that binds CD48. 2B4 is the only heterophilic receptor of the SLAM family, whose other members, e.g., NK-T-B-antigen (NTB-A), are self-ligands. We determined the structure of the complex between the N-terminal domains of mouse 2B4 and CD48, as well as the structures of unbound 2B4 and CD48. The complex displayed an association mode related to, yet distinct from, that of the NTB-A dimer. Binding was accompanied by the rigidification of flexible 2B4 regions containing most of the polymorphic residues across different species and receptor isoforms. We propose a model for 2B4-CD48 interactions that permits the intermixing of SLAM receptors with major histocompatibility complex-specific receptors in the NK cell immune synapse. This analysis revealed the basis for heterophilic recognition within the SLAM family.
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Affiliation(s)
- C Alejandro Velikovsky
- Center for Advanced Research in Biotechnology, W.M. Keck Laboratory for Structural Biology, University of Maryland Biotechnology Institute, Rockville, MD 20850, USA
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25
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Mankelow TJ, Burton N, Stefansdottir FO, Spring FA, Parsons SF, Pedersen JS, Oliveira CLP, Lammie D, Wess T, Mohandas N, Chasis JA, Brady RL, Anstee DJ. The Laminin 511/521-binding site on the Lutheran blood group glycoprotein is located at the flexible junction of Ig domains 2 and 3. Blood 2007; 110:3398-406. [PMID: 17638854 PMCID: PMC2200917 DOI: 10.1182/blood-2007-06-094748] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Lutheran blood group glycoprotein, first discovered on erythrocytes, is widely expressed in human tissues. It is a ligand for the alpha5 subunit of Laminin 511/521, an extracellular matrix protein. This interaction may contribute to vaso-occlusive events that are an important cause of morbidity in sickle cell disease. Using x-ray crystallography, small-angle x-ray scattering, and site-directed mutagenesis, we show that the extracellular region of Lutheran forms an extended structure with a distinctive bend between the second and third immunoglobulin-like domains. The linker between domains 2 and 3 appears to be flexible and is a critical determinant in maintaining an overall conformation for Lutheran that is capable of binding to Laminin. Mutagenesis studies indicate that Asp312 of Lutheran and the surrounding cluster of negatively charged residues in this linker region form the Laminin-binding site. Unusually, receptor binding is therefore not a function of the domains expected to be furthermost from the plasma membrane. These studies imply that structural flexibility of Lutheran may be essential for its interaction with Laminin and present a novel opportunity for the development of therapeutics for sickle cell disease.
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Affiliation(s)
- Tosti J Mankelow
- Bristol Institute for Transfusion Sciences, National Blood Service, Southmead Road, Bristol, United Kingdom.
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26
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Castro MAA, Oliveira MI, Nunes RJ, Fabre S, Barbosa R, Peixoto A, Brown MH, Parnes JR, Bismuth G, Moreira A, Rocha B, Carmo AM. Extracellular isoforms of CD6 generated by alternative splicing regulate targeting of CD6 to the immunological synapse. THE JOURNAL OF IMMUNOLOGY 2007; 178:4351-61. [PMID: 17371992 DOI: 10.4049/jimmunol.178.7.4351] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The great majority of mammalian genes yield multiple transcripts arising from differential mRNA processing, but in very few instances have alternative forms been assigned distinct functional properties. We have cloned and characterized a new isoform of the accessory molecule CD6 that lacks the CD166 binding domain and is expressed in rat and human primary cells. The novel isoform, CD6Deltad3, results from exon 5 skipping and consequently lacks the third scavenger receptor cysteine-rich (SRCR) domain of CD6. Differential expression of the SRCR domain 3 resulted in a remarkable functional difference: whereas full-length CD6 targeted to the immunological synapse, CD6Deltad3 was unable to localize at the T cell:APC interface during Ag presentation. Analysis of expression of CD6 variants showed that, while being more frequent in coexpression with full-length CD6, the CD6Deltad3 isoform constituted the sole species in a small percentage of T cells. In the rat thymus, CD6Deltad3 is less represented in double-positive thymocytes but is detectable in nearly 50% of single-positive CD4 or CD8 thymocytes, suggesting that CD6 switching between full-length and Deltad3 isoforms may be involved in thymic selection. Strikingly, CD6Deltad3 is markedly up-regulated upon activation of T lymphocytes, partially substituting full-length CD6, as evaluated by RT-PCR analysis at the single-cell level, by immunoblotting, and by flow cytometry using Abs recognizing SRCR domains 1 and 3 of human CD6. This elegant mechanism controlling the expression of the CD166 binding domain may help regulate signaling delivered by CD6, through different types of extracellular engagement.
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MESH Headings
- Activated-Leukocyte Cell Adhesion Molecule/metabolism
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Antigen-Presenting Cells/chemistry
- Antigen-Presenting Cells/immunology
- Antigens, CD/analysis
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/analysis
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Humans
- Lymphocyte Activation
- Molecular Sequence Data
- Protein Isoforms/analysis
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Protein Structure, Tertiary
- Rats
- Receptors, Scavenger/metabolism
- Sequence Deletion
- T-Lymphocytes/chemistry
- T-Lymphocytes/immunology
- Thymus Gland/immunology
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Affiliation(s)
- Mónica A A Castro
- Group of Cell Activation and Gene Expression, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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27
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Kearney A, Avramovic A, Castro MAA, Carmo AM, Davis SJ, van der Merwe PA. The contribution of conformational adjustments and long-range electrostatic forces to the CD2/CD58 interaction. J Biol Chem 2007; 282:13160-6. [PMID: 17344209 PMCID: PMC2771598 DOI: 10.1074/jbc.m700829200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD2 is a T cell surface molecule that enhances T and natural killer cell function by binding its ligands CD58 (humans) and CD48 (rodents) on antigen-presenting or target cells. Here we show that the CD2/CD58 interaction is enthalpically driven and accompanied by unfavorable entropic changes. Taken together with structural studies, this indicates that binding is accompanied by energetically significant conformational adjustments. Despite having a highly charged binding interface, neither the affinity nor the rate constants of the CD2/CD58 interaction were affected by changes in ionic strength, indicating that long-range electrostatic forces make no net contribution to binding.
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Affiliation(s)
- Alice Kearney
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
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Rich RL, Myszka DG. Survey of the year 2006 commercial optical biosensor literature. J Mol Recognit 2007; 20:300-66. [DOI: 10.1002/jmr.862] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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