501
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Ménasché G, Feldmann J, Fischer A, de Saint Basile G. Primary hemophagocytic syndromes point to a direct link between lymphocyte cytotoxicity and homeostasis. Immunol Rev 2005; 203:165-79. [PMID: 15661029 DOI: 10.1111/j.0105-2896.2005.00224.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hemophagocytic syndrome (HS) is a severe and often fatal syndrome resulting from potent and uncontrolled activation and proliferation of T-lymphocytes, leading to excessive macrophage activation and multiple deleterious effects. The onset of HS characterizes several inherited disorders in humans. In each condition, the molecular defect impairs the granule-dependent cytotoxic activity of lymphocytes, thus highlighting the determinant role of this function in driving the immune system to a state of equilibrium following infection. It has also been shown that some of the proteins required for lytic granule secretion are required for melanocyte function, leading to associated hypopigmentation in these conditions. This review focuses on several effectors of this secretory pathway, recently identified, because their defects cause these disorders, and discusses their role and molecular interactions in granule-dependent cytotoxic activity.
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Affiliation(s)
- Gael Ménasché
- INSERM U429, Hôpital Necker Enfants-Malades, Paris, France
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502
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Groves JT. Molekulare Organisation und Signaltransduktion an Kontaktstellen zwischen Membranen. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200461014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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503
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Groves JT. Molecular Organization and Signal Transduction at Intermembrane Junctions. Angew Chem Int Ed Engl 2005; 44:3524-38. [PMID: 15844101 DOI: 10.1002/anie.200461014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surfaces create an environment in which multiple forces conspire together to yield a wealth of complex chemical processes. This is especially true of cell membranes, whose fluidity and flexibility enables responsive feedback with surface chemical interactions in ways not generally seen with inorganic materials. Spatial pattern formation of cell-surface proteins at intermembrane junctions provides many beautiful examples of these phenomena, and is also emerging as a functional aspect of intercellular signaling. Correspondingly, the study of interactions of cell-membrane surfaces is attracting significant attention from cell biologists and physical chemists alike. This convergence is fueled be recent, exquisite observations of protein pattern formation events within living immunological synapses along with parallel advances in membrane reconstitution, manipulation, and imaging technologies.
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Affiliation(s)
- Jay T Groves
- Department of Chemistry, University of California Berkeley, USA.
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504
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Brossard C, Feuillet V, Schmitt A, Randriamampita C, Romao M, Raposo G, Trautmann A. Multifocal structure of the T cell - dendritic cell synapse. Eur J Immunol 2005; 35:1741-53. [PMID: 15909310 DOI: 10.1002/eji.200425857] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The structure of immunological synapses formed between murine naive T cells and mature dendritic cells has been subjected to a quantitative analysis. Immunofluorescence images of synapses formed in the absence of antigen show a diffuse synaptic accumulation of CD3 and LFA-1. In electron microscopy, these antigen-free synapses present a number of tight appositions (cleft size approximately 15 nm), all along the synapse. These tight appositions cover a significantly larger surface fraction of antigen-dependent synapses. In immunofluorescence, antigen-dependent synapses show multiple patches of CD3 and LFA-1 with a variable overlap. A similar distribution is observed for PKCtheta and talin. A concentric organization characteristic of prototypical synapses is rarely observed, even when dendritic cells are paralyzed by cytoskeletal poisons. In T-DC synapses, the interaction surface is composed of several tens of submicronic contact spots, with no large-scale segregation of CD3 and LFA-1. As a comparison, in T-B synapses, a central cluster of CD3 is frequently observed by immunofluorescence, and electron microscopy reveals a central tight apposition. Our data show that it is inappropriate to consider the concentric structure as a "mature synapse" and multifocal structures as immature.
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Affiliation(s)
- Cédric Brossard
- Département de Biologie Cellulaire, Institut Cochin, INSERM U567, CNRS UMR 8104, Université René Descartes, Paris, France
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505
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Puente LG, Mireau LR, Lysechko TL, Ostergaard HL. Phosphatidylinositol-3-kinase regulates PKCθ activity in cytotoxic T cells. Mol Immunol 2005; 42:1177-84. [PMID: 15829307 DOI: 10.1016/j.molimm.2004.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Indexed: 11/21/2022]
Abstract
Protein kinase C (PKC) theta plays a crucial role in T cell activation. We, therefore, examined the regulation of PKCtheta activity in cytotoxic T lymphocytes (CTL). We demonstrated that PMA did not stimulate PKCtheta activation and phospholipase C inhibition did not block anti-CD3-stimulated PKCtheta activation in a CTL clone. This suggests that diacylglycerol is neither sufficient nor required for PKCtheta activation. Furthermore, PKCtheta was only activated in a CTL clone stimulated with plate-bound anti-CD3 but not soluble anti-CD3. However, PMA or cross-linked anti-CD3 stimulated phosphorylation of PKCtheta as measured by a migratory shift, suggesting that phosphorylation was not sufficient for activity. Phosphatidylinositol 3-kinase activity was required for anti-CD3, but not PMA, stimulated phosphorylation and for immobilized anti-CD3-triggered PKCtheta activity. A substantial fraction of PKCtheta was constitutively membrane associated and PMA or CD3 stimulation did not significantly increase membrane association. Our data indicate that phosphorylation of PKCtheta is not a suitable surrogate measurement for PKCtheta activity and that additional, yet to be defined steps, are required for the regulation of PKCtheta enzymatic activity in CTL.
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Affiliation(s)
- Lawrence G Puente
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alta., Canada T6G2S2
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506
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Hoffmann P, Hofmeister R, Brischwein K, Brandl C, Crommer S, Bargou R, Itin C, Prang N, Baeuerle PA. Serial killing of tumor cells by cytotoxic T cells redirected with a CD19-/CD3-bispecific single-chain antibody construct. Int J Cancer 2005; 115:98-104. [PMID: 15688411 DOI: 10.1002/ijc.20908] [Citation(s) in RCA: 257] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Certain bispecific antibodies exhibit an extraordinary potency and efficacy for target cell lysis by eliciting a polyclonal T-cell response. One example is a CD19-/CD3-bispecific single-chain antibody construct (bscCD19xCD3), which at femtomolar concentrations can redirect cytotoxic T cells to eliminate human B lymphocytes, B lymphoma cell lines and patient-derived malignant B cells. Here we have further explored the basis for this high potency. Using video-assisted microscopy, bscCD19xCD3 was found to alter the motility and activity of T cells from a scanning to a killing mode. Individual T cells could eliminate multiple target cells within a 9 hr time period, resulting in nuclear fragmentation and membrane blebbing of target cells. Complete target cell elimination was observed within 24 hr at effector-to-target cell ratios as low as 1:5. Under optimal conditions, cell killing started within minutes after addition of bscCD19xCD3, suggesting that the rate of serial killing was mostly determined by T-cell movement and target cell scanning and lysis. At all times, T cells remained highly motile, and no clusters of T and target cells were induced by the bispecific antibody. Bystanding target-negative cells were not detectably affected. Repeated target cell lysis by bscCD19xCD3-activated T cells increased the proportion of CD19/CD3 double-positive T cells, which was most likely a consequence of transfer of CD19 from B to T cells during cytolytic synapse formation. To our knowledge, this is the first study showing that a bispecific antibody can sustain multiple rounds of target cell lysis by T cells.
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507
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von Herrath M, Homann D. Islet regeneration needed for overcoming autoimmune destruction - considerations on the pathogenesis of type 1 diabetes. Pediatr Diabetes 2005; 5 Suppl 2:23-8. [PMID: 15601371 DOI: 10.1111/j.1399-543x.2004.00076.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
How many new beta-cells need to be generated in order to withstand the attack of an 'average-strength' destructive autoimmune response? An answer to this question is central for the design of intervention approaches aimed at dampening or redirecting parts of the autoimmune response and allowing for the generation of new beta-cells. In this article, we consider quantitative and spatial restrictions of destructive T-cell activity, in balance with the regenerative capacity and neogenesis of beta-cells. We assume that the initial interaction between specific autoaggressive cytotoxic T-lymphocytes (CTL) and beta-cells is a terminal event leading to the elimination of the beta-cell and removal from the pool of potential sources for beta-cell replenishment. Furthermore, we propose that there may be no way to save an individual islet from complete destruction, once a few activated CTL effectors have gained entry, based on the fact that activated CTL are 'committed killers' and hard to turn off. Thus, mechanisms that restrict CTL access to islets or provide 'immune privilege' to defined locations within islets and/or ductal tissue are critical to allow beta-cell regeneration in the face of ongoing autoimmune destruction. The key to halting progression of type 1 diabetes pathogenesis should build on the observation that islets die in a highly non-synchronized fashion, at least during the more chronic disease course. These considerations suggest a compartmentalized view of the diseased pancreas so that substantial histopathological differences among individual islets may be exploited to facilitate preservation and/or regeneration of selected islets. The recent development of novel technologies will allow more precise quantification of in vivo destruction and regeneration in order to test these hypotheses.
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Affiliation(s)
- Matthias von Herrath
- Immune Regulation Laboratory, La Jolla Institute for Allergy and Immunology, 10355 Science Center Drive, San Diego, CA 92121, USA.
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508
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Raja SM, Metkar SS, Höning S, Wang B, Russin WA, Pipalia NH, Menaa C, Belting M, Cao X, Dressel R, Froelich CJ. A Novel Mechanism for Protein Delivery. J Biol Chem 2005; 280:20752-61. [PMID: 15788411 DOI: 10.1074/jbc.m501181200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular interaction of secreted granzyme B-serglycin complexes with target cells remains undefined. Targets exposed to double-labeled granzyme B-serglycin complexes show solely the uptake of granzyme B. An in vitro model demonstrates the exchange of the granzyme from serglycin to immobilized, sulfated glycosaminoglycans. Using a combination of cell binding and internalization assays, granzyme B was found to exchange to sulfated glycosaminoglycans and, depending on the cell type, to higher affinity sites. Apoptosis induced by purified granzyme B and cytotoxic T-cells was diminished in targets with reduced cell surface glycosaminoglycan content. A mechanism of delivery is proposed entailing electrostatic transfer of granzyme B from serglycin to cell surface proteins.
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Affiliation(s)
- Srikumar M Raja
- Department of Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois 60201, USA.
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509
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Badour K, Zhang J, Siminovitch KA. Involvement of the Wiskott-Aldrich syndrome protein and other actin regulatory adaptors in T cell activation. Semin Immunol 2005; 16:395-407. [PMID: 15541654 DOI: 10.1016/j.smim.2004.08.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The actin cytoskeleton is a dynamic structure recognized for many years as integral to the coupling of external stimuli to cell activation and ensuing changes in morphology and movement. It is only recently, however, that a molecular understanding of actin involvement in these activities has emerged coincident with the identification of cytosolic signaling effectors that couple extracellular stimuli to induction of actin nucleation. Notable among these actin regulatory effectors are members of the Wiskott-Aldrich syndrome protein (WASp) family, a group of cytoskeletal adaptors imbued with the capacity to connect various signal transduction pathways to the Arp 2/3 complex and Arp 2/3-mediated actin polymerization. In T cells, the functional characterization of WASp and other actin-modulatory adaptors has proved instrumental in delineating the molecular interactions evoking actin cytoskeletal reorganization downstream of antigen receptor engagement and in clarifying the influence of actin-based processes on T cell activation. In this review, the structural and functional properties of the major actin regulatory cytoskeletal adaptors in T cells are described with an emphasis on the roles of these proteins in fostering the TCR actin cytoskeletal interplay required for induction of T cell activation and expression of dynamic effector responses.
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Affiliation(s)
- Karen Badour
- Department of Medicine, McLaughlin Centre of Molecular Medicine, University of Toronto, Mount Sinai Hospital, Samuel Lunenfeld and Toronto General Hospital Research Institutes, 600 University Avenue, #656A, Toronto, Ont., Canada M5G 1X5.
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510
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Offner S, Hofmeister R, Romaniuk A, Kufer P, Baeuerle PA. Induction of regular cytolytic T cell synapses by bispecific single-chain antibody constructs on MHC class I-negative tumor cells. Mol Immunol 2005; 43:763-71. [PMID: 16360021 DOI: 10.1016/j.molimm.2005.03.007] [Citation(s) in RCA: 255] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Accepted: 03/04/2005] [Indexed: 11/19/2022]
Abstract
Certain bispecific single-chain antibody constructs exhibit an extraordinary potency for polyclonal T cell engagement and target cell lysis. Here we studied the structural basis for this potency, using laser scanning confocal microscopy. Cytolytic human T cell synapses could be triggered either by addition of a specific peptide antigen or an Ep-CAM-/CD3-bispecific T cell engager (BiTE). Both kinds of synapses showed a comparable distribution of all protein markers investigated. Two other BiTEs constructed from different Ep-CAM-specific antibodies gave similar results. BiTEs could also induce lytic synapses between human T cells and a MHC class I-negative, Ep-CAM cDNA-transfected cell line resulting in potent target cell lysis. This shows that certain T cell recognition molecules on target cells are dispensable for synapse formation and BiTE activity, and suggests that BiTE-activated polyclonal T cells may ignore major immune evasion mechanisms of tumor cells in vivo, such as loss of MHC class I expression.
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Affiliation(s)
- Sonja Offner
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
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511
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Anikeeva N, Somersalo K, Sims TN, Thomas VK, Dustin ML, Sykulev Y. Distinct role of lymphocyte function-associated antigen-1 in mediating effective cytolytic activity by cytotoxic T lymphocytes. Proc Natl Acad Sci U S A 2005; 102:6437-42. [PMID: 15851656 PMCID: PMC1088394 DOI: 10.1073/pnas.0502467102] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellular adhesion molecule 1 determined a unique positioning of granules near the interface. These data provide evidence that LFA-1 delivers a distinct signal essential for directing released cytolytic granules to the surface of antigen-bearing target cells to mediate the effective destruction of these cells by CTL.
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Affiliation(s)
- Nadia Anikeeva
- Department of Microbiology and Immunology and Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA
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512
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Linkermann A, Qian J, Lettau M, Kabelitz D, Janssen O. Considering Fas ligand as a target for therapy. Expert Opin Ther Targets 2005; 9:119-34. [PMID: 15757486 DOI: 10.1517/14728222.9.1.119] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
About a decade ago, the death factor Fas ligand (FasL) was identified as the natural trigger of Fas/CD95-dependent apoptosis and as an inducer of Fas-dependent activation-induced cell death. Meanwhile, it is known that this molecule not only contributes to target cell lysis in the immune system but also to the establishment of immune privilege and tumour survival. Because delivering a specific antiproliferative signal to T lymphocytes is of major biomedical interest, the FasL/Fas system has gained much attention over the last few years. However, only recently it became evident that the biology of FasL is more complex than initially anticipated. FasL displays a complex pattern of inducible and constitutive expression associated with a number of different functions as a death factor or a co-stimulatory/accessory molecule in lymphocyte activation. Thus, side effects are likely to occur following systemic administration of, for example, anti-FasL medication, not only because of the constitutive FasL expression on cells within immune privileged tissues and vascular endothelium. In addition, FasL comes in different forms: as a surface molecule, as a protease-shed soluble variant or secreted in vesicles. Because increased levels of soluble FasL (sFasL) have been determined in various immunological and non-immunological diseases, it has been suggested that sFasL might serve as a prognostic or diagnostic marker even though the pathophysiological cause for its enhanced production is hardly known in most cases. This review summarises the current facts and ideas about the clinical and pharmacological potential of FasL and sFasL as targets for therapeutic interventions.
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Affiliation(s)
- Andreas Linkermann
- Medical Center Schleswig-Holstein Campus Kiel, Institute of Immunology, Michaelisstr. 5, D-24105 Kiel, Germany
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513
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Onfelt B, Davis DM. Can membrane nanotubes facilitate communication between immune cells? Biochem Soc Trans 2005; 32:676-8. [PMID: 15493985 DOI: 10.1042/bst0320676] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent observations have revealed that intercellular connections can be formed through membrane nanotubes. These delicate structures could facilitate transport of organelles and membrane proteins between cells. The sharing of cell surface and cytoplasmic components between cells could be commonplace in biology, but an important physiological role for membrane nanotubes between immune cells is difficult to test with current technology.
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Affiliation(s)
- B Onfelt
- Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College, London SW7 SAZ, UK
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514
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Coombs D, Goldstein B. Effects of the geometry of the immunological synapse on the delivery of effector molecules. Biophys J 2005; 87:2215-20. [PMID: 15454424 PMCID: PMC1304647 DOI: 10.1529/biophysj.104.045674] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Recent experiments focusing on the function of the immunological synapse formed between a T cell and an antigen-presenting cell raise many questions about its purpose. We examine the proposal that the close apposition of the cell membranes in the central region of the synapse acts to focus T-cell secretions on the target cell, thus reducing the effect on nearby cells. We show that the efficiency of targeted T-cell responses to closely apposed cells is only weakly dependent on the distance between the cells. We also calculate effective (diffusion-limited) rates of binding and unbinding for molecules secreted within the synapse. We apply our model to the stimulation of B cells by secreted interleukin-4 (IL-4), and find that very few molecules of IL-4 need be released to essentially saturate the IL-4 receptors on the B-cell surface.
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Affiliation(s)
- Daniel Coombs
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada.
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515
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Poenie M, Kuhn J, Combs J. Real-time visualization of the cytoskeleton and effector functions in T cells. Curr Opin Immunol 2005; 16:428-38. [PMID: 15245735 DOI: 10.1016/j.coi.2004.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Advances in imaging technology have been essential to our understanding of T-cell activation and effector functions. Much of the progress stems from the use of fluorescent fusion proteins combined with high resolution imaging techniques, including confocal and multiphoton microscopy. However, these techniques have limitations, and other modes of imaging, including new developments on the horizon, might add promising new tools for the visualization of cytoskeleton-dependent processes in living cells.
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Affiliation(s)
- Martin Poenie
- Department of Molecular Cell and Developmental Biology, University of Texas at Austin, 78712, USA.
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516
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Abstract
Cells of the immune system communicate via the formation of receptor-containing adhesive junctions termed immunological synapses. Recently, retroviruses have been shown to subvert this process in order to pass directly from infected to uninfected immune cells. Such cell-cell viral dissemination appears to function by triggering existing cellular pathways involved in antigen presentation and T-cell communication. This mode of viral spread has important consequences for both the virus and the host cells in terms of viral pathogenesis and viral resistance to immune and therapeutic intervention. This review summarises the current knowledge concerning virological synapses induced by retroviruses.
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Affiliation(s)
- Clare Jolly
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE.
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517
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Poupot M, Pont F, Fournié JJ. Profiling blood lymphocyte interactions with cancer cells uncovers the innate reactivity of human gamma delta T cells to anaplastic large cell lymphoma. THE JOURNAL OF IMMUNOLOGY 2005; 174:1717-22. [PMID: 15661936 DOI: 10.4049/jimmunol.174.3.1717] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Quantifying the contacts that circulating lymphocytes have with cancer cells is useful, because their deficit favors malignancy progression. All normal lymphocytes contact, scan, and acquire membrane fragments (trogocytosis) from foreign cells for their immunosurveillance. So in this study, we used the in vitro trogocytosis of PKH67-stained cancer cell lines as a measure of their interactions with bulks of PBMC freshly isolated from healthy donors. Allogeneic PBMC mixed and coincubated in vitro for 1 h did not trogocytosis, whereas in the same conditions CD20(+), CD4(+), CD8(+), gammadelta T, and CD16(+) PBMC interacted strongly with the cancer cells. Although most unprimed lymphoid effectors of innate (NK) and adaptive (B and T) immunity from healthy donors spontaneously trogocytosed different tumoral cell lines, some carcinoma cell lines could escape them in the coculture. This also uncovered the strong interactions of circulating Vgamma9/Vdelta2(+) central memory gammadelta T cells with anaplastic large cell lymphoma. These interaction profiles were stable upon time for healthy blood donors but were different with other tumors and blood donors. This profiling provides interaction signatures for the immunomonitoring of cancer.
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MESH Headings
- Adult
- B-Lymphocytes/immunology
- Cell Communication/immunology
- Cell Line, Transformed
- Coculture Techniques
- HT29 Cells
- Humans
- Immunity, Innate
- Jurkat Cells
- K562 Cells
- Leukocytes, Mononuclear/cytology
- Lymphocyte Subsets/immunology
- Lymphocyte Subsets/metabolism
- Lymphoma, Large B-Cell, Diffuse/immunology
- Lymphoma, Large B-Cell, Diffuse/pathology
- Receptors, Antigen, T-Cell, gamma-delta/blood
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- U937 Cells
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Affiliation(s)
- Mary Poupot
- Departement Oncogénèse and Signalisation dans les Cellules Hématopoiétiques, Unité 563 de l'Institut National de la Santé et de la Recherche Médicale, Centre de Physiopathologie de Toulouse Purpan, Boite Postale, Toulouse, France
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518
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Abstract
Interactions between cells of the immune system can lead to intercellular exchange of cell-surface molecules. Recent studies indicate that such exchange can be bidirectional when natural killer cells interact with their target cells. Sprent reviews the mechanisms involved in cell-cell molecular transfer and the receptor-ligand interactions involved.
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519
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Purtic B, Pitcher LA, van Oers NSC, Wülfing C. T cell receptor (TCR) clustering in the immunological synapse integrates TCR and costimulatory signaling in selected T cells. Proc Natl Acad Sci U S A 2005; 102:2904-9. [PMID: 15703298 PMCID: PMC549456 DOI: 10.1073/pnas.0406867102] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During T cell activation, T cell receptors (TCR) cluster at the center of the T cell/antigen-presenting cell interface forming a key component of the immunological synapse. The function of this TCR clustering is still unresolved. A comprehensive search for such a function yielded a very limited and specific result. A micrometer-scale receptor clustering integrated the TCR and CD28 signals required for IL-2 secretion in primary 5C.C7 T cells, a low-affinity/avidity TCR system. 5C.C7 TCR signaling itself was not affected. In addition, central TCR accumulation was not required for any T cell effector function tested in three other TCR transgenic models. Central TCR accumulation thus had a specific role in signaling integration in low-affinity T cells.
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Affiliation(s)
- Bozidar Purtic
- Center for Immunology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
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520
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Koneru M, Schaer D, Monu N, Ayala A, Frey AB. Defective Proximal TCR Signaling Inhibits CD8+ Tumor-Infiltrating Lymphocyte Lytic Function. THE JOURNAL OF IMMUNOLOGY 2005; 174:1830-40. [PMID: 15699109 DOI: 10.4049/jimmunol.174.4.1830] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CD8+ tumor-infiltrating lymphocytes (TIL) are severely deficient in cytolysis, a defect that may permit tumor escape from immune-mediated destruction. Because lytic function is dependent upon TCR signaling, we have tested the hypothesis that primary TIL have defective signaling by analysis of the localization and activation status of TIL proteins important in TCR-mediated signaling. Upon conjugate formation with cognate target cells in vitro, TIL do not recruit granzyme B+ granules, the microtubule-organizing center, F-actin, Wiskott-Aldrich syndrome protein, nor proline rich tyrosine kinase-2 to the target cell contact site. In addition, TIL do not flux calcium nor demonstrate proximal tyrosine kinase activity, deficiencies likely to underlie failure to fully activate the lytic machinery. Confocal microscopy and fluorescence resonance energy transfer analyses demonstrate that TIL are triggered by conjugate formation in that the TCR, p56lck, CD3zeta, LFA-1, lipid rafts, ZAP70, and linker for activation of T cells localize at the TIL:tumor cell contact site, and CD43 and CD45 are excluded. However, proximal TCR signaling is blocked upon conjugate formation because the inhibitory motif of p56lck is rapidly phosphorylated (Y505) and COOH-terminal Src kinase is recruited to the contact site, while Src homology 2 domain-containing protein phosphatase 2 is cytoplasmic. Our data support a novel mechanism explaining how tumor-induced inactivation of proximal TCR signaling regulates lytic function of antitumor T cells.
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MESH Headings
- Actins/deficiency
- Actins/metabolism
- Animals
- CD2 Antigens/metabolism
- CD3 Complex/metabolism
- CD8 Antigens/metabolism
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/pathology
- Calcium/metabolism
- Cell Line, Tumor
- Cell Separation
- Cytoplasmic Granules/immunology
- Cytoplasmic Granules/metabolism
- Cytotoxicity, Immunologic
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism
- Lymphocytes, Tumor-Infiltrating/enzymology
- Lymphocytes, Tumor-Infiltrating/immunology
- Lymphocytes, Tumor-Infiltrating/metabolism
- Lymphocytes, Tumor-Infiltrating/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Phosphorylation
- Phosphotyrosine/metabolism
- Protein Transport/immunology
- Protein-Tyrosine Kinases/deficiency
- Protein-Tyrosine Kinases/metabolism
- Receptor-CD3 Complex, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/deficiency
- Receptors, Antigen, T-Cell/physiology
- Signal Transduction/immunology
- ZAP-70 Protein-Tyrosine Kinase
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Affiliation(s)
- Mythili Koneru
- Department of Cell Biology and Kaplan Cancer Center, New York University School of Medicine, New York, NY 10016, USA
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521
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Jacobs R, Heiken H, Schmidt RE. Mutual interference of HIV and natural killer cell-mediated immune response. Mol Immunol 2005; 42:239-49. [PMID: 15488611 DOI: 10.1016/j.molimm.2004.06.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Natural killer (NK) cells represent important early effector cells in innate immune defense as they exert their functions without prior sensitization. They participate in regulation of innate and adaptive immune responses and hematopoiesis by producing various cytokines and chemokines. In addition, NK cells lyse virally infected and malignant cells raising them to multifunctional members of the first line of defense. Unlike other lymphocytes they lack specific antigen receptors. They rather bind cells using ubiquitous molecules and communicate via a pattern of receptors specific for MHC-I molecules with their counterparts. In general, successful binding of the receptors delivers an inhibitory signal to NK cells thus sparing the target cell from lysis. In contrast, down-regulated or altered MHC-I expression as frequently observed during virus infection or on malignant cells prevents ligation of inhibitory receptors and MHC-I paralyzing inhibition and thus inducing lysis of the target cell. In human immunodeficiency virus (HIV) infection NK cells are of central importance since they can combat viral infection itself and opportunistic pathogens like fungi and protozoa that usually spread during the course of HIV infection. However, various studies have reported alterations in HIV patients affecting NK cell numbers and functions that might negatively influence course and severity of the disease. This review will focus on the mutual interference of NK cells and the HI virus.
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Affiliation(s)
- Roland Jacobs
- Department of Clinical Immunology, Hannover Medical School, 30625 Hannover, Germany.
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522
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Dupré L, Andolfi G, Tangye SG, Clementi R, Locatelli F, Aricò M, Aiuti A, Roncarolo MG. SAP controls the cytolytic activity of CD8+ T cells against EBV-infected cells. Blood 2005; 105:4383-9. [PMID: 15677558 DOI: 10.1182/blood-2004-08-3269] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The adaptor protein SAP regulates signaling through signaling lymphocytic activation molecule (SLAM)-family receptors expressed on T and natural killer (NK) cells. In patients affected by X-linked lymphoproliferative (XLP) disease, mutations in the SH2D1A gene result in defective lytic activity. However, the mechanism by which SAP controls cytotoxic activity remains unclear. T-cell-receptor (TCR) activation of CD8(+) cytotoxic T cells (CTLs) results in down-regulation of SAP, suggesting that this protein is involved in early activation events. Here, we show that SAP-deficient CTLs from patients with XLP and hemophagocytic lymphohistiocytosis (HLH) display a specific lytic defect against autologous and allogeneic Epstein-Barr virus (EBV)-positive B cells. This defect is associated with the defective polarization of 2B4, perforin, and lipid rafts at the contact area of CTLs with EBV-positive targets. Blockade of 2B4 in normal CTLs reproduces the defects in lysis and polarization observed in SAP-deficient CTLs. Expression and regulation of the SLAM-family receptors SLAM, CD84, and 2B4, as well as the lytic effectors perforin and granzyme-B are normal in SAP-deficient CTLs. In addition, TCR stimulation leads to normal proliferation and production of interleukin 2 (IL-2), IL-4, and interferon-gamma (IFN-gamma). These results demonstrate that the SAP/2B4 pathway plays a key role in CTL lytic activity against EBV-positive targets by promoting the polarization of the lytic machinery.
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Affiliation(s)
- Loïc Dupré
- San Raffaele Telethon Institute for Gene Therapy, via Olgettina 58, 20132 Milan, Italy
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523
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Jacobelli J, Andres PG, Boisvert J, Krummel MF. New views of the immunological synapse: variations in assembly and function. Curr Opin Immunol 2005; 16:345-52. [PMID: 15134784 DOI: 10.1016/j.coi.2004.03.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The interaction of T cells with antigen-presenting cells results in the formation of a contact face, termed the immunological synapse. The prototypical dynamics of this process are well established and involve cessation of crawling, a highly fluid 'immature' synapse phase during which signaling is initiated, and ultimately the formation of a 'mature' synapse characterized by centralized and peripheral supramolecular activating complexes. Ongoing research is directed towards defining how these supramolecular assemblies are formed and, more importantly, to what end. With regard to the former, progress has been made in defining the order in which various molecules are recruited to signaling centers in prototypical settings. With regard to the latter, however, the issue now appears more complex, as both developmental changes in T cells and variations in the environment appear to modulate features of mature synapse development. Although many details of the immunological synapse have been established, emerging evidence suggests a great variability in the ultimate form of these contacts and their effects on T-cell functions.
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Affiliation(s)
- Jordan Jacobelli
- Department of Pathology, University of California at San Francisco, 513 Parnassus Avenue, San Francisco, California 94143-0511, USA.
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524
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Abstract
Rho GTPases are molecular switches controlling a broad range of cellular processes including lymphocyte activation. Not surprisingly, Rho GTPases are now recognized as pivotal regulators of antigen-specific T cell activation by APCs and immunological synapse formation. This review summarizes recent advances in our understanding of how Rho GTPase-dependent pathways control T lymphocyte motility, polarization and activation.
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Affiliation(s)
- M Deckert
- INSERM Unit 576, Hôpital de l'Archet, BP3079, 06202 Nice, France.
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525
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Pardo J, Bosque A, Brehm R, Wallich R, Naval J, Müllbacher A, Anel A, Simon MM. Apoptotic pathways are selectively activated by granzyme A and/or granzyme B in CTL-mediated target cell lysis. ACTA ACUST UNITED AC 2004; 167:457-68. [PMID: 15534000 PMCID: PMC2172484 DOI: 10.1083/jcb.200406115] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Purified cytolytic T lymphocyte (CTL) proteases granzyme (gzm)A and gzmB with sublytic dose of perforin (perf) initiate distinct proapoptotic pathways. Their physiological relevance in CTL-mediated target cell apoptosis is elusive. Using ex vivo virus-immune CD8(+) T cells from mice deficient in perf, gzmA and/or gzmB, and the Fas-resistant EL4.F15 tumor target cell, we show that (a) CTL from gzmA(-/-) or gzmB(-/-) mice similarly induced early proapoptotic features, such as phosphatidyl serine (PS) exposure on plasma membrane, Delta Psi(m) loss, and reactive oxygen radical generation, though with distinct kinetics; (b) CTL from gzmA(-/-) but not from gzmB(-/-) mice activate caspase 3 and 9; (c) PS exposure induced by CTL from gzmA(-/-) or gzmB(-/-) mice is prevented, respectively, by caspase inhibitors or by reactive oxygen scavengers without interfering with target cell death; and (d) all gzm-induced apoptotic features analyzed depend critically on perf. Thus, perf is the principal regulator in CTL-mediated and gzm-facilitated intracellular processes. The ability of gzmA and gzmB to induce multiple independent cell death pathways may be the hosts response to circumvent evasion strategies of pathogens and tumors.
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Affiliation(s)
- Julián Pardo
- Departmento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, E-50009 Zaragoza, Spain
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526
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Wetzel SA, McKeithan TW, Parker DC. Peptide-Specific Intercellular Transfer of MHC Class II to CD4+ T Cells Directly from the Immunological Synapse upon Cellular Dissociation. THE JOURNAL OF IMMUNOLOGY 2004; 174:80-9. [PMID: 15611230 DOI: 10.4049/jimmunol.174.1.80] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The transfer of membrane proteins from APC to T cells was initially described in the 1970s, and subsequent work has described two mechanisms of transfer: APC-derived exosomes and direct transfer of small packets, while cells remain conjugated. Using fibroblast APC expressing a GFP-tagged I-E(k) molecule with covalently attached antigenic peptide, we observed a third mechanism in live cell imaging: T cells spontaneously dissociating from APC often capture MHC:peptide complexes directly from the immunological synapse. Using two I-E(k)-restricted murine TCR transgenic T cells with different peptide specificity, we show in this study that the MHC transfer is peptide specific. Using blocking Abs, we found that MHC:peptide transfer in this system requires direct TCR-MHC:peptide interactions and is augmented by costimulation through CD28-CD80 interactions. Capture of the GFP-tagged MHC:peptide complexes correlates with an activated phenotype of the T cell, elevated CD69 with down-modulated TCR. The transferred MHC:peptide molecules transferred to the T cell are associated with molecules that imply continued TCR signaling; p56(lck), phosphotyrosine, and polarization of the actin cytoskeleton.
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MESH Headings
- Animals
- Antigen Presentation/immunology
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/metabolism
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/immunology
- Antigens, Differentiation, T-Lymphocyte/metabolism
- CD4-Positive T-Lymphocytes/immunology
- Cell Communication/immunology
- Cells, Cultured
- Fibroblasts/immunology
- Fibroblasts/metabolism
- Flow Cytometry
- Green Fluorescent Proteins/genetics
- Histocompatibility Antigens Class II/immunology
- Lectins, C-Type
- Lymphocyte Activation/immunology
- Mice
- Mice, Transgenic
- Peptides/immunology
- Receptors, Antigen, T-Cell/immunology
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Affiliation(s)
- Scott A Wetzel
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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527
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Standeven LJ, Carlin LM, Borszcz P, Davis DM, Burshtyn DN. The actin cytoskeleton controls the efficiency of killer Ig-like receptor accumulation at inhibitory NK cell immune synapses. THE JOURNAL OF IMMUNOLOGY 2004; 173:5617-25. [PMID: 15494512 DOI: 10.4049/jimmunol.173.9.5617] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Killer cell Ig-like receptors (KIRs) are MHC class I-specific receptors expressed in NK and T lymphocytes. KIR antagonism of activation signals occurs at the immune synapse between the effector and target cells. The processes that regulate clustering of KIR are not well defined. We have expressed KIR-GFP receptor chimeras in two human NK-like lines, YTS and NK92. In this study, we show that the frequency of KIR enrichment at the synapse was decreased for a KIR that lacks a portion of the cytoplasmic tail. Strikingly, blocking actin polymerization with a high dose of cytochalasin D also substantially decreased clustering of KIR as well as KIR-induced clustering of HLA-C-GFP in target cells. However, the effect of inhibiting actin polymerization was only clearly evident at the earlier time points after cell mixing, and eventually clustering of KIR and HLA-C occurred independently of actin remodeling. Although treatment with anti-LFA-1 also decreased conjugate formation, the frequency of KIR clustering remained normal within the population of conjugates that did form, suggesting that the effect of cytochalasin D is not solely through LFA-1. Collectively, these data suggest that the actin cytoskeleton and the cytoplasmic tail of KIR regulate the efficiency by which KIR accumulates at inhibitory NK cell synapses.
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Affiliation(s)
- Leah J Standeven
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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528
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Abstract
Granzymes (gzm) are major components of the granules of cytolytic lymphocytes, natural killer and cytotoxic T cells. Their generally accepted mode of action consists of their directed secretion towards a virus-infected or neoplastic target cell and perforin-dependent delivery to the target cell cytosol, where they engage in various actions resulting in target cell apoptosis. Here, based on observations of infection of gzmAxB(-/-) mice with ectromelia virus, mousepox, we propose an additional--and distinct--function for gzmA and B. In this model, gzm constitute one of the first lines of defence of immune cells against virus infection of immune cells themselves. Accordingly, endogenous gzm interfere with viral replication in cytolytic lymphocytes either directly, as a result of their proteolytic activity, leading to destruction of viral proteins, or indirectly, via: (i) processes akin to the caspase cascade when acting as effector molecules in the induction of target cell apoptosis; or (ii) their capacity to induce early inflammatory mediators. We discuss the predictions of the model in the light of available data.
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Affiliation(s)
- Matthias Regner
- Molecular Immunology and Immunopathology, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.
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529
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Vanherberghen B, Andersson K, Carlin LM, Nolte-'t Hoen ENM, Williams GS, Höglund P, Davis DM. Human and murine inhibitory natural killer cell receptors transfer from natural killer cells to target cells. Proc Natl Acad Sci U S A 2004; 101:16873-8. [PMID: 15550544 PMCID: PMC534731 DOI: 10.1073/pnas.0406240101] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intercellular transfer of proteins across the immunological synapse is emerging as a common outcome of immune surveillance. We previously reported that target-cell MHC class I protein transfers onto natural killer (NK) cells expressing cognate killer Ig-like receptors (KIRs). We now show that, for both murine and human cells, target cells expressing inhibitory MHC class I ligands acquire cognate inhibitory NK receptors. Other cell-surface proteins, but not a cytoplasmic dye, also transferred from human NK cells to target cells across an inhibitory immunological synapse. The number of KIRs acquired from NK cells correlated with the level of expression of cognate MHC class I protein on target cells. Treatment with cytoskeletal inhibitors demonstrated that the target-cell cytoskeleton influences intercellular transfer of proteins in both directions. In contrast to constitutively expressed KIRs, a fraction of acquired KIRs could be removed by mild acid wash, demonstrating a difference between some of the acquired KIRs and constitutively expressed KIRs. An accumulation of phosphotyrosine at the location of the transferred KIRs implies a signaling capacity for NK cell proteins transferred to target cells. Thus, intercellular protein transfer between immune cells is bidirectional and could facilitate new aspects of immune cell communication.
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Affiliation(s)
- Bruno Vanherberghen
- Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College, London SW7 2AZ, United Kingdom
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530
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Abstract
The immunological synapse (IS) has proved to be a stimulating concept, particularly in provoking discussion on the similarity of intercellular communication controlling disparate biological processes. Recent studies have clarified some of the underlying molecular mechanisms and functions of the IS. For both T cells and natural killer (NK) cells, assembly of the IS can be described in stages with distinct cytoskeletal requirements. Functions of the IS vary with circumstance and include directing secretion and integrating positive and negative signals to determine the extent of response.
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Affiliation(s)
- Daniel M Davis
- Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London, UK, SW7 2AZ.
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531
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Vyas YM, Maniar H, Lyddane CE, Sadelain M, Dupont B. Ligand binding to inhibitory killer cell Ig-like receptors induce colocalization with Src homology domain 2-containing protein tyrosine phosphatase 1 and interruption of ongoing activation signals. THE JOURNAL OF IMMUNOLOGY 2004; 173:1571-8. [PMID: 15265884 DOI: 10.4049/jimmunol.173.3.1571] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Interaction of NK cells with target cells leads to formation of an immunological synapse (IS) at the contact site. NK cells form two distinctly different IS, the inhibitory NK cell IS (NKIS) and the cytolytic NKIS. Cognate ligand binding is sufficient to induce clustering of inhibitory killer cell Ig-like receptors (KIR) and phosphorylation of both the receptor and the phosphatase Src homology domain 2-containing protein tyrosine phosphatase 1 (SHP-1). Recruitment and activation of SHP-1 by a signaling competent inhibitory receptor are essential early events for NK cell inhibition. We have in the present study used three-dimensional immunofluorescence microscopy to analyze distribution of inhibitory KIR, SHP-1, LFA-1, and lipid rafts within the NKIS during cytolytic and noncytolytic interactions. NK clones retrovirally transduced with the inhibitory KIR2DL3 gene fused to GFP demonstrate colocalization of KIR2DL3 with SHP-1 in the center of early inhibitory NKIS. Ligand binding translocates the receptor to the center of the IS where activation signals are accumulating and provides a docking site for SHP-1. SHP-1 and rafts cluster in the center of early inhibitory NKIS and late cytolytic NKIS, and whereas rafts continue to increase in size in cytolytic conjugates, they are rapidly dissolved in inhibitory conjugates. Furthermore, rafts are essential only for cytolytic, not for inhibitory, outcome. These results indicate that the outcome of NK cell-target cell interactions is dictated by early quantitative differences in cumulative activating and inhibitory signals.
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MESH Headings
- Cytotoxicity, Immunologic
- Enzyme Activation/drug effects
- Genes, Reporter
- Green Fluorescent Proteins
- Humans
- Imaging, Three-Dimensional
- Intracellular Signaling Peptides and Proteins
- Killer Cells, Natural/drug effects
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Killer Cells, Natural/ultrastructure
- Ligands
- Luminescent Proteins/analysis
- Luminescent Proteins/genetics
- Lymphocyte Function-Associated Antigen-1/metabolism
- Membrane Microdomains/metabolism
- Microscopy, Fluorescence/methods
- Phosphorylation/drug effects
- Protein Phosphatase 1
- Protein Processing, Post-Translational/drug effects
- Protein Tyrosine Phosphatase, Non-Receptor Type 6
- Protein Tyrosine Phosphatases/metabolism
- Receptors, Immunologic/drug effects
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Receptors, KIR
- Receptors, KIR2DL3
- Recombinant Fusion Proteins/analysis
- Transduction, Genetic
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Affiliation(s)
- Yatin M Vyas
- Department of Pediatrics, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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532
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Onfelt B, Nedvetzki S, Yanagi K, Davis DM. Cutting edge: Membrane nanotubes connect immune cells. THE JOURNAL OF IMMUNOLOGY 2004; 173:1511-3. [PMID: 15265877 DOI: 10.4049/jimmunol.173.3.1511] [Citation(s) in RCA: 293] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We present evidence that nanotubular highways, or membrane nanotubes, facilitate a novel mechanism for intercellular communication in the immune system. Nanotubes were seen to connect multiple cells together and were readily formed between a variety of cell types, including human peripheral blood NK cells, macrophages, and EBV-transformed B cells. Nanotubes could be created upon disassembly of the immunological synapse, as cells move apart. Thus, nanotubular networks could be assembled from transient immunological synapses. Nanotubes were seen to contain GFP-tagged cell surface class I MHC protein expressed in one of the connected cells. Moreover, GPI-conjugated to GFP originating from one cell was transferred onto the surface of another at the connection with a nanotube. Thus, nanotubes can traffic cell surface proteins between immune cells over many tens of microns. Determining whether there are physiological functions for nanotubes is an intriguing new goal for cellular immunology.
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Affiliation(s)
- Björn Onfelt
- Department of Biological Sciences, Imperial College, London, United Kingdom
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533
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Boisvert J, Edmondson S, Krummel MF. Immunological synapse formation licenses CD40-CD40L accumulations at T-APC contact sites. THE JOURNAL OF IMMUNOLOGY 2004; 173:3647-52. [PMID: 15356109 DOI: 10.4049/jimmunol.173.6.3647] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The maintenance of tolerance is likely to rely on the ability of a T cell to polarize surface molecules providing "help" to only specific APCs. The formation of a mature immunological synapse leads to concentration of the TCR at the APC interface. In this study, we show that the CD40-CD154 receptor-ligand pair is also highly concentrated into a central region of the synapse on mouse lymphocytes only after the formation of the TCR/CD3 c-SMAC. Concentration of this ligand was strictly dependent on TCR recognition, the binding of ICAM-1 to T cell integrins and the presence of an intact cytoskeleton in the T cells. This may provide a novel explanation for the specificity of T cell help directing the help signal to the site of Ag receptor signal. It may also serve as a site for these molecular aggregates to coassociate and/or internalize alongside other signaling receptors.
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Affiliation(s)
- Judie Boisvert
- Department of Pathology, University of California, San Francisco, CA 94143, USA
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534
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Roda-Navarro P, Mittelbrunn M, Ortega M, Howie D, Terhorst C, Sánchez-Madrid F, Fernández-Ruiz E. Dynamic redistribution of the activating 2B4/SAP complex at the cytotoxic NK cell immune synapse. THE JOURNAL OF IMMUNOLOGY 2004; 173:3640-6. [PMID: 15356108 DOI: 10.4049/jimmunol.173.6.3640] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The 2B4 molecule (CD244) has been described as a coreceptor in human NK cell activation. However, the behavior of 2B4 during the cytotoxic NK cell immune synapse (NK-IS) formation remains undetermined. In this study, we demonstrate the redistribution of 2B4 and the signaling adaptor molecule, signaling lymphocyte activation molecule-associated protein (SAP), to the cytotoxic NK-IS upon formation of conjugates between resting NK cells and EBV-infected 721.221 human cells. Confocal microscopy showed that 2B4 localized at the central supramolecular activation cluster, surrounded by a peripheral supramolecular activation cluster containing talin within NK cell and ICAM-1 on target cells. Videomicroscopy studies with 2B4-GFP-transfected NK cells revealed that 2B4 redistributed to cytotoxic NK-IS as soon as the cell contact occurred. Simultaneously, a SAP-GFP also clustered at the contact site, where it remained during the interaction period. The 2B4 molecular clusters remained bound to the target cell even after NK cell detachment. These results underscore the function of 2B4 as an adhesion molecule and suggest a relevant role in the initial binding, scanning of target cells, and formation of cytotoxic NK-IS. Finally, these findings are indicative of an important role of the activating 2B4/signaling lymphocyte activation molecule-associated protein complex during the recognition of EBV-infected cells.
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MESH Headings
- Antigens, CD/blood
- Antigens, CD/metabolism
- Antigens, CD/physiology
- Carrier Proteins/blood
- Carrier Proteins/metabolism
- Carrier Proteins/physiology
- Cell Communication/immunology
- Cell Line, Transformed
- Cell Transformation, Viral/immunology
- Cytotoxicity Tests, Immunologic
- Cytotoxicity, Immunologic
- Herpesvirus 4, Human/immunology
- Humans
- Interphase/immunology
- Intracellular Signaling Peptides and Proteins
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lymphocyte Activation
- Membrane Glycoproteins/blood
- Membrane Glycoproteins/metabolism
- Membrane Glycoproteins/physiology
- Receptors, Immunologic/blood
- Receptors, Immunologic/metabolism
- Receptors, Immunologic/physiology
- Signal Transduction/immunology
- Signaling Lymphocytic Activation Molecule Associated Protein
- Signaling Lymphocytic Activation Molecule Family
- Subcellular Fractions/immunology
- Subcellular Fractions/metabolism
- src Homology Domains/immunology
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Affiliation(s)
- Pedro Roda-Navarro
- Unidad de Biología Molecular, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Spain
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535
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Braun V, Fraisier V, Raposo G, Hurbain I, Sibarita JB, Chavrier P, Galli T, Niedergang F. TI-VAMP/VAMP7 is required for optimal phagocytosis of opsonised particles in macrophages. EMBO J 2004; 23:4166-76. [PMID: 15470500 PMCID: PMC524391 DOI: 10.1038/sj.emboj.7600427] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2004] [Accepted: 09/06/2004] [Indexed: 01/17/2023] Open
Abstract
Phagocytosis relies on extension of plasmalemmal pseudopods generated by focal actin polymerisation and delivery of membranes from intracellular pools. Here we show that compartments of the late endocytic pathway, bearing the tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP/VAMP7), are recruited upon particle binding and undergo exocytosis before phagosome sealing in macrophages during Fc receptor (FcR)-mediated phagocytosis. Expression of the dominant-negative amino-terminal domain of TI-VAMP or depletion of TI-VAMP with small interfering RNAs inhibited phagocytosis mediated by Fc or complement receptors. In addition, inhibition of TI-VAMP activity led to a reduced exocytosis of late endocytic vesicles and this resulted in an early blockade of pseudopod extension, as observed by scanning electron microscopy. Therefore, TI-VAMP defines a new pathway of membrane delivery required for optimal FcR-mediated phagocytosis.
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Affiliation(s)
- Virginie Braun
- Membrane and Cytoskeleton Dynamics group, UMR144 CNRS-Institut Curie, Paris, France
| | - Vincent Fraisier
- Digital Imaging Platform, UMR144 CNRS-Institut Curie, Paris, France
| | - Graça Raposo
- Electron Microscopy Group, UMR144 CNRS-Institut Curie, Paris, France
| | - Ilse Hurbain
- Electron Microscopy Group, UMR144 CNRS-Institut Curie, Paris, France
| | | | - Philippe Chavrier
- Membrane and Cytoskeleton Dynamics group, UMR144 CNRS-Institut Curie, Paris, France
| | - Thierry Galli
- Membrane Traffic and Neuronal Plasticity, INSERM U536, Institut du Fer-à-Moulin, Paris, France
| | - Florence Niedergang
- Membrane and Cytoskeleton Dynamics group, UMR144 CNRS-Institut Curie, Paris, France
- UMR144 CNRS-Institut Curie, 26, rue d'Ulm, 75248 Paris cedex 05, France. Tel.: +33 1 42 34 63 67; Fax: +33 1 42 34 63 77; E-mail:
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536
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Friedl P, Storim J. Diversity in immune-cell interactions: states and functions of the immunological synapse. Trends Cell Biol 2004; 14:557-67. [PMID: 15450978 DOI: 10.1016/j.tcb.2004.09.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The contact-dependent exchange of signals between epithelial and neuronal cells results from close membrane-membrane appositions, which are stabilized for years by polarized adhesion, cytoskeletal assemblies and extracellular scaffold proteins. By contrast, owing to a lack of scaffold proteins, interactions between immune cells such as T lymphocytes and antigen-presenting cells (APCs) comprise a spectrum of structurally diverse and short-lived interaction modes that last from minutes to hours. Signals exchanged between T cells and APCs are generated in a specific contact region, termed the "immunological synapse", that coordinates cytoskeletal dynamics with the T-cell receptor (TCR), the engagement of accessory receptors and membrane-proximal signaling. Recent data shed light on the different physical and molecular interaction modes that occur between T cells and APCs, including their dynamics and transition stages, and their consequences for signaling, activation and T-cell effector function.
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Affiliation(s)
- Peter Friedl
- Rudolf-Virchow Center, DFG Research Center for Experimental Biomedicine and Department of Dermatology, University of Würzburg, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany.
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537
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Marwali MR, MacLeod MA, Muzia DN, Takei F. Lipid rafts mediate association of LFA-1 and CD3 and formation of the immunological synapse of CTL. THE JOURNAL OF IMMUNOLOGY 2004; 173:2960-7. [PMID: 15322154 DOI: 10.4049/jimmunol.173.5.2960] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Lipid rafts accumulate in the immunological synapse formed by an organized assembly of the TCR/CD3, LFA-1, and signaling molecules. However, the precise role of lipid rafts in the formation of the immunological synapse is unclear. In this study, we show that LFA-1 on CTL is constitutively active and mediates Ag-independent binding of CTL to target cells expressing its ligands. LFA-1 and CD3 on CTL, but not resting T cells, colocalize in lipid rafts. Binding of LFA-1 on CTL to targets initiates the formation of the immunological synapse, which is formed by LFA-1, CD3, and ganglioside GM1 distributed in the periphery of the cell contact site and cholesterol is more widely distributed. The formation of this synapse is Ag independent, but the recognition of Ag by the TCR induces accumulation of tyrosine phosphorylated proteins in the synapse as well as redistribution of the microtubule organization center toward the cell contact site. Our results suggest that LFA-1 recruits lipid rafts and the TCR/CD3 to the synapse, and facilitates efficient and rapid activation of CTL.
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538
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Blanchard N, Decraene M, Yang K, Miro-Mur F, Amigorena S, Hivroz C. Strong and durable TCR clustering at the T/dendritic cell immune synapse is not required for NFAT activation and IFN-gamma production in human CD4+ T cells. THE JOURNAL OF IMMUNOLOGY 2004; 173:3062-72. [PMID: 15322166 DOI: 10.4049/jimmunol.173.5.3062] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The exact function of TCR clustering and organized macromolecular patterns at the immune synapse between APCs and T lymphocytes is unclear. Using human immature or mature dendritic cells (DCs) and autologous CD4(+) effector T cells, we demonstrate that, within a given conjugate, mature DCs induce strong and long-lasting TCR clustering and protein kinase C-theta translocation in a superantigen dose-dependent manner. Moreover, mature DCs promote CD43 exclusion in a dose-independent manner. In contrast, immature DCs are less potent at inducing these molecular rearrangements. Using these models to correlate T cell functions with the frequency, the intensity, and the duration of TCR clustering, we show, in Jurkat T cells, that weak and transient TCR clustering is sufficient to promote TCR down-modulation, protein kinase C-theta translocation at the synapse, and substantial NFAT transcriptional activation. Moreover, we show, in CD4(+) T cell blasts, that strong TCR clustering is required for neither TCR down-modulation nor optimal IFN-gamma production. Together, our results demonstrate that some CD4(+) functional responses, such as cytokine production, are independent of central supramolecular activation cluster formation.
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Affiliation(s)
- Nicolas Blanchard
- Institut National de la Santé et de la Recherche Médicale, Unité 520, Institut Curie, Paris, France
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539
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Shafer-Weaver KA, Sayers T, Kuhns DB, Strobl SL, Burkett MW, Baseler M, Malyguine A. Evaluating the cytotoxicity of innate immune effector cells using the GrB ELISPOT assay. J Transl Med 2004; 2:31. [PMID: 15380049 PMCID: PMC522821 DOI: 10.1186/1479-5876-2-31] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Accepted: 09/20/2004] [Indexed: 11/10/2022] Open
Abstract
Background This study assessed the Granzyme B (GrB) ELISPOT as a viable alternative to the 51Cr-release assay for measuring cytotoxic activity of innate immune effector cells. We strategically selected the GrB ELISPOT assay because GrB is a hallmark effector molecule of cell-mediated destruction of target cells. Methods We optimized the GrB ELISPOT assay using the human-derived TALL-104 cytotoxic cell line as effectors against K562 target cells. Titration studies were performed to assess whether the ELISPOT assay could accurately enumerate the number of GrB-secreting effector cells. TALL-104 were treated with various secretion inhibitors and utilized in the GrB ELISPOT to determine if GrB measured in the ELISPOT was due to degranulation of effector cells. Additionally, CD107a expression on effector cells after effector-target interaction was utilized to further confirm the mechanism of GrB release by TALL-104 and lymphokine-activated killer (LAK) cells. Direct comparisons between the GrB ELISPOT, the IFN-γ ELISPOT and the standard 51Cr-release assays were made using human LAK cells. Results Titration studies demonstrated a strong correlation between the number of TALL-104 and LAK effector cells and the number of GrB spots per well. GrB secretion was detectable within 10 min of effector-target contact with optimal secretion observed at 3–4 h; in contrast, optimal IFN-γ secretion was not observed until 24 h. The protein secretion inhibitor, brefeldin A, did not inhibit the release of GrB but did abrogate IFN-γ production by TALL-104 cells. GrB secretion was abrogated by BAPTA-AM (1,2-bis-(2-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid tetra(acetoxymethyl) ester), which sequesters intracellular Ca2+, thereby preventing degranulation. The number of effector cells expressing the degranulation associated glycoprotein CD107a increased after interaction with target cells and correlated with the stimulated release of GrB measured in the ELISPOT assay. Conclusions Because of its high sensitivity and ability to estimate cytotoxic effector cell frequency, the GrB ELISPOT assay is a viable alternative to the 51Cr-release assay to measure MHC non-restricted cytotoxic activity of innate immune cells. Compared to the IFN-γ ELISPOT assay, the GrB ELISPOT may be a more direct measure of cytotoxic cell activity. Because GrB is one of the primary effector molecules in natural killer (NK) cell-mediated killing, detection and enumeration of GrB secreting effector cells can provide valuable insight with regards to innate immunological responses.
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Affiliation(s)
- Kimberly A Shafer-Weaver
- Laboratory of Cell-Mediated Immunity, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Thomas Sayers
- Laboratory of Experimental Immunology, Intramural Research Support Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Douglas B Kuhns
- Neutrophil Monitoring Laboratory, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Susan L Strobl
- Laboratory of Cell-Mediated Immunity, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Mark W Burkett
- Laboratory of Cell-Mediated Immunity, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Michael Baseler
- Clinical Services Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
| | - Anatoli Malyguine
- Laboratory of Cell-Mediated Immunity, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD USA
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540
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Otten HG, van Ginkel WGJ, Hagenbeek A, Petersen EJ. Prevalence and clinical significance of resistance to perforin- and FAS-mediated cell death in leukemia. Leukemia 2004; 18:1401-5. [PMID: 15215873 DOI: 10.1038/sj.leu.2403414] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Killer lymphocytes play a central therapeutic role in graft-versus-leukemia following allogeneic hematopoietic stem cell transplantation (HSCT). The Perforin/Granzyme and FAS/CD95 pathways are of crucial importance in tumor cell elimination by killer cells. In this study, we have examined whether hematological malignancies are resistant to perforin and anti-FAS antibodies. Leukemic cells were studied from 29 patients suffering either from acute or chronic myeloid leukemia (AML or CML), acute or chronic lymphoid leukemia, or non-Hodgkin's lymphoma. An average of 49 vs 5% of specific cell killing was found when using perforin vs anti-FAS antibodies, respectively. Interestingly, resistance towards both perforin and anti-FAS antibodies was found exclusively in leukemic cells from patients with myeloid leukemia. Analysis of leukemic cells from patients with CML, suffering from leukemia relapse after HSCT and given donor lymphocyte infusion (DLI) to induce remission, indicated that the effectiveness of treatment with DLI was not associated with sensitivity of leukemic cells to perforin. In conclusion, resistance towards anti-FAS antibodies is a common phenomenon in leukemia/lymphoma, whereas perforin resistance occurs only in myeloid leukemia. However, as a single parameter, perforin resistance does not appear to be suitable to predict the outcome of DLI.
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Affiliation(s)
- H G Otten
- Jordan Laboratory for Hemato-Oncology, Department of Hematology, University Medical Center Utrecht, Utrecht, The Netherlands.
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541
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Abstract
Cell-to-cell viral transmission facilitates the propagation of HIV-1 and human T cell leukemia virus type 1. Mechanisms of cell-to-cell transmission by retroviruses were not well understood until the recent description of virological synapses (VSs). VSs function as specialized sites of immune cell-to-cell contact that direct virus infection. Deciphering the molecular mechanisms of VS formation provides a fascinating insight into how pathogens subvert immune cell communication programs and achieve viral spread.
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Affiliation(s)
- Vincent Piguet
- Department of Dermatology and Venereology, University Hospital of Geneva, Geneva, Switzerland.
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542
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Dustin ML. Stop and Go Traffic to Tune T Cell Responses. Immunity 2004; 21:305-14. [PMID: 15357942 DOI: 10.1016/j.immuni.2004.08.016] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 08/09/2004] [Accepted: 08/10/2004] [Indexed: 01/11/2023]
Abstract
Adaptive immune responses are initiated by interactions of T cells with antigen-presenting cells, but the basic nature of these interactions during an immune response in vivo has been a matter of speculation. While some in vitro systems provide evidence for stable interactions, referred to as immunological synapses, compelling evidence supports T cell activation through serial transient interactions. Deep tissue intravital and organ culture microscopy studies suggest that both modes of interaction are employed, but new issues have emerged. This review will discuss in vitro results that framed the hypotheses that are currently being tested in vivo. I present a model in which TCR stop signals compete with chemokine-mediated go signals to adjust the duration of immunological synapse formation and tune the immune response between tolerance and full activation.
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Affiliation(s)
- Michael L Dustin
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10021, USA.
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543
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Waterhouse NJ, Clarke CJP, Sedelies KA, Teng MW, Trapani JA. Cytotoxic lymphocytes; instigators of dramatic target cell death. Biochem Pharmacol 2004; 68:1033-40. [PMID: 15313398 DOI: 10.1016/j.bcp.2004.05.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Accepted: 05/27/2004] [Indexed: 11/30/2022]
Abstract
Most mammalian cells are constantly threatened by viral infection and oncogenic transformation. To maintain healthy function of organs and tissues it is critical that afflicted cells are efficiently detected and removed. Cytotoxic lymphocytes (CL) are chiefly responsible for efficiently seeking out and eliminating damaged or infected cells. It is known that CLs must specifically recognize and bind to their targets, but the molecular events that occur within the target cell that lead to its death are still poorly understood. The two main processes initiated by CLs to induce target cell death are mediated by ligation of surface receptors or release of toxic proteins from secretory granules (granule exocytosis) of the CL. Here we review some of the key findings that have defined our knowledge of the granule exocytosis-mediated pathways to CL-mediated killing and discuss recent insights that challenge conventional views in the important area of CL effector function.
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Affiliation(s)
- Nigel J Waterhouse
- Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett St, Melbourne, Vic. 8006, Australia.
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544
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Morales-Tirado V, Johannson S, Hanson E, Howell A, Zhang J, Siminovitch KA, Fowell DJ. Cutting edge: selective requirement for the Wiskott-Aldrich syndrome protein in cytokine, but not chemokine, secretion by CD4+ T cells. THE JOURNAL OF IMMUNOLOGY 2004; 173:726-30. [PMID: 15240657 DOI: 10.4049/jimmunol.173.2.726] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanism of cytokine secretion is not well understood, but cytokines appear to be synthesized and released in a polarized fashion toward an Ag-specific target cell. In this study, we demonstrate that the Wiskott-Aldrich syndrome protein (WASp) is an essential component of the cytokine secretory pathway in CD4(+) T cells. Murine WASp-deficient CD4(+) T cells fail to polarize cytokines toward a target and show an unexpected and striking block in cytokine secretion. In contrast, chemokine secretion and trafficking of plasma membrane proteins, transported via the constitutive secretory pathway, are unaffected by the lack of WASp. These results suggest that CD4(+) T cell cytokines require a specialized, WASp-dependent pathway for cellular traffic and/or vesicle release that is distinct from that required for chemokine release. We propose that the use of different secretory pathways for cytokines and chemokines enables CD4(+) T cell activity to be further fine-tuned to serve specialized effector functions.
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Affiliation(s)
- Vanessa Morales-Tirado
- David H. Smith Center for Vaccine Biology and Immunology, Aab Institute of Biomedical Sciences, and Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA
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545
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Watson ARO, Lee WT. Differences in signaling molecule organization between naive and memory CD4+ T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2004; 173:33-41. [PMID: 15210756 DOI: 10.4049/jimmunol.173.1.33] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The immunological synapse is a highly organized complex formed at the junction between Ag-specific T cells and APCs as a prelude to cell activation. Although its exact role in modulating T cell signaling is unknown, it is commonly believed that the immunological synapse is the site of cross-talk between the T cell and APC (or target). We have examined the synapses formed by naive and memory CD4 cells during Ag-specific cognate interactions with APCs. We show that the mature immunological synapse forms more quickly during memory T cell activation. We further show that the composition of the synapse found in naive or memory cell conjugates with APCs is distinct with the tyrosine phosphatase, CD45, being a more integral component of the mature synapses formed by memory cells. Finally, we show that signaling molecules, including CD45, are preassociated in discrete, lipid-raft microdomains in resting memory cells but not in naive cells. Thus, enhanced memory cell responses may be due to intrinsic properties of signaling molecule organization.
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Affiliation(s)
- Andrew R O Watson
- Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY 12201-0509, USA
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546
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Batista A, Millán J, Mittelbrunn M, Sánchez-Madrid F, Alonso MA. Recruitment of transferrin receptor to immunological synapse in response to TCR engagement. THE JOURNAL OF IMMUNOLOGY 2004; 172:6709-14. [PMID: 15153487 DOI: 10.4049/jimmunol.172.11.6709] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cell receptor engagement by an APC induces the formation of a highly organized complex of surface receptors and intracellular signaling molecules, known as the immunological synapse, at the site of cell-cell contact. The transferrin receptor (TfR, CD71) is normally present in the plasma membrane and recycling endosomes. In this study, we show that, although the TfR is typically absent from lipid rafts at steady state, stimulation with a mitogenic mixture of anti-CD3 Abs of human Jurkat T cells leads to a rapid compartmentalization of the TfR into lipid rafts accompanying that of CD3epsilon and activated Lck. This change occurs very rapidly and is accompanied by an increase in the surface expression of the TfR, probably by translocation from an internal endosomal pool. TfR recruitment to lipid rafts was also observed in primary T cells treated with mitogenic anti-CD3 Abs and in Jurkat T cell-APC conjugates. The use of beads coated with Abs indicates that the surface and endosomal TfR pools redistribute to the contact site region in response to engagement of CD28 and CD3. In T cell-APC conjugates, the T cell TfR endosomal pool relocates beneath the contact site, whereas surface TfR localizes to the peripheral ring of the immunological synapse. In the presence of specific anti-TfR Abs, the total number of T cell-APC contacts and the percentage of conjugates with CD3 and Lck translocated to the contact site were reduced. Our results therefore suggest the involvement of the TfR in the formation of the immunological synapse.
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Affiliation(s)
- Alicia Batista
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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547
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Taner SB, Onfelt B, Pirinen NJ, McCann FE, Magee AI, Davis DM. Control of Immune Responses by Trafficking Cell Surface Proteins, Vesicles and Lipid Rafts to and from the Immunological Synapse. Traffic 2004; 5:651-61. [PMID: 15296490 DOI: 10.1111/j.1600-0854.2004.00214.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Supramolecular clusters at the immunological synapse provide a mechanism for structuring complex communication networks between cells of the immune system. Regulating intra- and intercellular trafficking of proteins and lipids to and from the immunological synapse provides an additional level of complexity in determining the functional outcome of immune cell interactions. An emergent principle is that molecules requiring tightly regulated cell surface expression, e.g. negative regulators of cell activation or molecules promoting cytotoxicity, are trafficked to the immunological synapse from intracellular secretory as required lysosomes. Many molecules required for the early stages of the intercellular communication are already present at the cell surface, sometimes in lipid rafts, and are rapidly translocated laterally to the intercellular contact. Our understanding of these events critically depends on utilizing appropriate technologies for probing supramolecular recognition in live cells. Thus, we also present here a critical discussion of the technologies used to study lipid rafts and, more broadly, a map of the spatial and temporal dimensions covered by current live cell physical techniques, highlighting where advances are needed to exceed current spatial and temporal boundaries.
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Affiliation(s)
- Sabrina B Taner
- Department of Biological Sciences, Imperial College London, SW7 2AZ, UK
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548
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Garçon F, Bismuth G, Isnardon D, Olive D, Nunès JA. Tec Kinase Migrates to the T Cell-APC Interface Independently of Its Pleckstrin Homology Domain. THE JOURNAL OF IMMUNOLOGY 2004; 173:770-5. [PMID: 15240663 DOI: 10.4049/jimmunol.173.2.770] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tec is the prototypical member of the Tec tyrosine kinases family, which plays an important role in T cell signaling. We show in this study that Tec translocates to the immunological synapse when a T cell contacts a dendritic cell. Surprisingly, the presence of the pleckstrin homology (PH) domain of Tec is not required for this accumulation, and despite a strong activation of 3'-phosphorylated phosphoinositide lipids synthesis during the synapse formation, the Tec PH domain is not redistributed to the T cell plasma membrane. In contrast, we demonstrate that an active Src homology 3 domain is absolutely required, underlining the essential role played by this part of the molecule in the recruitment and/or stabilization of Tec at the immunological synapse. Our results nevertheless suggest that the PH domain controls the kinase activity of the molecule in vivo. We finally demonstrate that the two domains are necessary to trigger transcriptional events following Ag presentation. These data support a model in which the plasma membrane recruitment of the PH-containing protein Tec is not dependent on the production of 3'-phosphorylated phosphoinositide lipids by the PI3K, but rather on an intact Src homology 3 domain.
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Affiliation(s)
- Fabien Garçon
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 599, Université de la Méditerranée, Marseille, France
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549
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Stinchcombe J, Bossi G, Griffiths GM. Linking albinism and immunity: the secrets of secretory lysosomes. Science 2004; 305:55-9. [PMID: 15232098 DOI: 10.1126/science.1095291] [Citation(s) in RCA: 267] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Lysosomes are membrane-bound organelles that are found in all mammalian cells and contain hydrolases and lipases required for protein and membrane degradation. In many cells of the immune system, lysosomes also contain secretory proteins that can be released by regulated exocytosis in response to an external stimulus, providing different cell types with a wide range of effector functions. Melanosomes also use a lysosome-related organelle to secrete melanin for pigmentation. Links between albinism and immunity in patients have uncovered a number of key proteins required for lysosomal secretion and have revealed a versatile secretory mechanism that can be fine-tuned by distinct interactions in different cell types.
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Affiliation(s)
- Jane Stinchcombe
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
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550
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Sanni TB, Masilamani M, Kabat J, Coligan JE, Borrego F. Exclusion of lipid rafts and decreased mobility of CD94/NKG2A receptors at the inhibitory NK cell synapse. Mol Biol Cell 2004; 15:3210-23. [PMID: 15133125 PMCID: PMC452577 DOI: 10.1091/mbc.e03-11-0779] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 04/16/2004] [Accepted: 04/27/2004] [Indexed: 12/27/2022] Open
Abstract
CD94/NKG2A is an inhibitory receptor expressed by most human natural killer (NK) cells and a subset of T cells that recognizes human leukocyte antigen E (HLA-E) on potential target cells. To elucidate the cell surface dynamics of CD94/NKG2A receptors, we have expressed CD94/NKG2A-EGFP receptors in the rat basophilic leukemia (RBL) cell line. Photobleaching experiments revealed that CD94/NKG2A-EGFP receptors move freely within the plasma membrane and accumulate at the site of contact with ligand. The enriched CD94/NKG2A-EGFP is markedly less mobile than the nonligated receptor. We observed that not only are lipid rafts not required for receptor polarization, they are excluded from the site of receptor contact with the ligand. Furthermore, the lipid raft patches normally observed at the sites where FcepsilonR1 activation receptors are cross-linked were not observed when CD94/NKG2A was coengaged along with the activation receptor. These results suggest that immobilization of the CD94/NKG2A receptors at ligation sites not only promote sustenance of the inhibitory signal, but by lipid rafts exclusion prevent formation of activation signaling complexes.
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MESH Headings
- Animals
- Antigens, CD/analysis
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Cell Line, Tumor
- Gene Expression
- Green Fluorescent Proteins/analysis
- Green Fluorescent Proteins/genetics
- Humans
- Killer Cells, Natural/physiology
- Lectins, C-Type/analysis
- Lectins, C-Type/genetics
- Lectins, C-Type/metabolism
- Membrane Microdomains/immunology
- Membrane Microdomains/physiology
- NK Cell Lectin-Like Receptor Subfamily C
- NK Cell Lectin-Like Receptor Subfamily D
- Photobleaching
- Rats
- Receptors, Immunologic/analysis
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, Natural Killer Cell
- Signal Transduction/physiology
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Affiliation(s)
- Tolib B Sanni
- Receptor Cell Biology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
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