451
|
Carlin LM, Eleme K, McCann FE, Davis DM. Intercellular transfer and supramolecular organization of human leukocyte antigen C at inhibitory natural killer cell immune synapses. J Exp Med 2001; 194:1507-17. [PMID: 11714757 PMCID: PMC2193674 DOI: 10.1084/jem.194.10.1507] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
After accumulation of target cell human leukocyte antigen (HLA)-C at inhibitory natural killer (NK) cell immune synapses, some HLA-C transfers from target cells to NK cell plasma membranes and cytoplasm. This unexpected intercellular transfer of HLA-C is dependent on NK receptor recognition, since HLA-Cw6 or -Cw4 but not -Cw3 transfer to an NK transfectant expressing killer Ig-like receptor (KIR)2DL1. Strikingly, live-cell time-lapse laser scanning confocal microscopy shows vesicles containing target cell green fluorescent protein-tagged HLA-C migrating away from immune synapses into NK cells. Unlike clustering of HLA-C at the immune synapse, intercellular transfer of HLA-C is dependent on NK cell ATP, but not target cell ATP. However, the intercellular transfer of HLA-C is not dependent on active polymerization of the actin cytoskeleton. In addition, different arrangements of HLA-C are seen at inhibitory NK immune synapses, and these alter as NK synapses mature, but in a fashion distinct from that seen upon T cell activation.
Collapse
Affiliation(s)
- L M Carlin
- Department of Biological Sciences, Sir Alexander Fleming Building, Imperial College of Science, Technology, and Medicine, South Kensington, London SW7 2AZ, United Kingdom
| | | | | | | |
Collapse
|
452
|
Sirim P, Zeitlmann L, Kellersch B, Falk CS, Schendel DJ, Kolanus W. Calcium signaling through the beta 2-cytoplasmic domain of LFA-1 requires intracellular elements of the T cell receptor complex. J Biol Chem 2001; 276:42945-56. [PMID: 11559699 DOI: 10.1074/jbc.m103224200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta(2) integrin LFA-1 is an important cell-cell adhesion receptor of the immune system. Evidence suggests that the molecule also participates in signaling and co-stimulatory function. We show here that clustering of the intracellular domain of the beta(2) chain but not of the alpha(L)- or beta(1)-cytoplasmic domains, respectively, triggers intracellular Ca(2+) mobilization in Jurkat cells. A beta(2)-specific NPXF motif, located in the C-terminal portion of the beta(2) tail, is required for Ca(2+) signaling, and we show that this motif is important for the induction of allo-specific target cell lysis by cytotoxic T cells in vitro. Significantly, the Ca(2+)-signaling capacity of the beta(2) integrin is abrogated in T cells that do not express the T cell receptor but may be reconstituted by co-expression of the T cell receptor-zeta chain. Our data suggest a specific function of the cytoplasmic domain of the beta(2) integrin chain in T cell signaling.
Collapse
Affiliation(s)
- P Sirim
- Laboratorium für Molekulare Biologie, Genzentrum der Universität München, Germany
| | | | | | | | | | | |
Collapse
|
453
|
Katsumata O, Hara-Yokoyama M, Sautès-Fridman C, Nagatsuka Y, Katada T, Hirabayashi Y, Shimizu K, Fujita-Yoshigaki J, Sugiya H, Furuyama S. Association of FcgammaRII with low-density detergent-resistant membranes is important for cross-linking-dependent initiation of the tyrosine phosphorylation pathway and superoxide generation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5814-23. [PMID: 11698455 DOI: 10.4049/jimmunol.167.10.5814] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
IgG immune complexes trigger humoral immune responses by cross-linking of FcRs for IgG (FcgammaRs). In the present study, we investigated role of lipid rafts, glycolipid- and cholesterol-rich membrane microdomains, in the FcgammaR-mediated responses. In retinoic acid-differentiated HL-60 cells, cross-linking of FcgammaRs resulted in a marked increase in the tyrosine phosphorylation of FcgammaRIIa, p58(lyn), and p120(c-cbl), which was inhibited by a specific inhibitor of Src family protein tyrosine kinases. After cross-linking, FcgammaRs and tyrosine-phosphorylated proteins including p120(c-cbl) were found in the low-density detergent-resistant membrane (DRM) fractions isolated by sucrose-density gradient ultracentrifugation. The association of FcgammaRs as well as p120(c-cbl) with DRMs did not depend on the tyrosine phosphorylation. When endogenous cholesterol was reduced with methyl-beta-cyclodextrin, the cross-linking did not induce the association of FcgammaRs as well as p120(c-cbl) with DRMs. In addition, although the physical association between FcgammaRIIa and p58(lyn) was not impaired, the cross-linking did not induce the tyrosine phosphorylation. In human neutrophils, superoxide generation induced by opsonized zymosan or chemoattractant fMLP was not affected or increased, respectively, after the methyl-beta-cyclodextrin treatment, but the superoxide generation induced by the insoluble immune complex via FcgammaRII was markedly reduced. Accordingly, we conclude that the cross-linking-dependent association of FcgammaRII to lipid rafts is important for the activation of FcgammaRII-associated Src family protein tyrosine kinases to initiate the tyrosine phosphorylation cascade leading to superoxide generation.
Collapse
Affiliation(s)
- O Katsumata
- Department of Physiology, Nihon University School of Dentistry, Matsudo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
454
|
Delon J, Kaibuchi K, Germain RN. Exclusion of CD43 from the immunological synapse is mediated by phosphorylation-regulated relocation of the cytoskeletal adaptor moesin. Immunity 2001; 15:691-701. [PMID: 11728332 DOI: 10.1016/s1074-7613(01)00231-x] [Citation(s) in RCA: 225] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Formation of the immunological synapse requires TCR signal-dependent protein redistribution. However, the specific molecular mechanisms controlling protein relocation are not well defined. Moesin is a widely expressed phospho-protein that links many transmembrane molecules to the cortical actin cytoskeleton. Here, we demonstrate that TCR-induced exclusion of the large sialoprotein CD43 from the synapse is an active event mediated by its reversible binding to moesin. Our results also reveal that relocalization of moesin is associated with changes in the phosphorylation status of this cytoskeletal adaptor protein. Finally, these findings raise the possibility that the change in moesin localization resulting from TCR engagement modifies the overall topology of the lymphocyte membrane and facilitates molecular interactions at the site of presenting cell contact.
Collapse
Affiliation(s)
- J Delon
- Laboratory of Immunology, Lymphocyte Biology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | |
Collapse
|
455
|
Abraham C, Miller J. Molecular mechanisms of IL-2 gene regulation following costimulation through LFA-1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5193-201. [PMID: 11673532 DOI: 10.4049/jimmunol.167.9.5193] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The integrin LFA-1 serves as an accessory molecule in T cell activation. In addition to its well-known role as an adhesion molecule, LFA-1 can contribute to T cell activation and up-regulation of IL-2 gene expression. However, the specific mechanisms by which LFA-1 influences T cell activation have not been elucidated. Therefore, we examined the impact of LFA-1:ICAM-1 interactions on transcriptional and posttranscriptional IL-2 gene regulation, using a costimulation-negative cell line transfected with MHC class II alone, or in combination with ICAM-1 or B7-1. IL-2 transcription was assessed utilizing transgenic mice expressing an IL-2 promoter luciferase reporter construct crossed to DO11.10 TCR-transgenic mice, and IL-2 mRNA stability was evaluated by real-time RT-PCR. Comparison of naive and previously activated T cells demonstrates a dramatic increase in IL-2-luciferase transcription in activated T cells that can, in part, be attributed to downstream signaling events. Costimulation through LFA-1 enhances transcription of the transgenic reporter construct across a wide Ag dose range, but does not affect IL-2 mRNA stability. In contrast, CD28 costimulation is clearly mediated through up-regulation of IL-2 transcription and through enhancement of mRNA stability. These results indicate that the primary pathway whereby engagement of LFA-1 through its ligand ICAM-1 up-regulates IL-2 gene expression is through enhanced IL-2 transcription, in the absence of any effect on IL-2 mRNA stabilization.
Collapse
Affiliation(s)
- C Abraham
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | | |
Collapse
|
456
|
Dykstra M, Cherukuri A, Pierce SK. Rafts and synapses in the spatial organization of immune cell signaling receptors. J Leukoc Biol 2001. [DOI: 10.1189/jlb.70.5.699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Michelle Dykstra
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Anu Cherukuri
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Susan K. Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| |
Collapse
|
457
|
Roumier A, Olivo-Marin JC, Arpin M, Michel F, Martin M, Mangeat P, Acuto O, Dautry-Varsat A, Alcover A. The membrane-microfilament linker ezrin is involved in the formation of the immunological synapse and in T cell activation. Immunity 2001; 15:715-28. [PMID: 11728334 DOI: 10.1016/s1074-7613(01)00225-4] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Dynamic interactions between membrane and cytoskeleton components are crucial for T cell antigen recognition and subsequent cellular activation. We report here that the membrane-microfilament linker ezrin plays an important role in these processes. First, ezrin relocalizes to the contact area between T cells and stimulatory antigen-presenting cells (APCs), accumulating in F-actin-rich membrane protrusions at the periphery of the immunological synapse. Second, T cell receptor (TCR)-mediated intracellular signals are sufficient to induce ezrin relocalization, indicating that this protein is an effector of TCR signaling. Third, overexpression of the membrane binding domain of ezrin perturbs T cell receptor clustering in the T cell-APC contact area and inhibits the activation of nuclear factor for activated T cells (NF-AT).
Collapse
Affiliation(s)
- A Roumier
- Unité de Biologie des Interactions Cellulaires, CNRS URA 1960, Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
458
|
Villalba M, Bi K, Rodriguez F, Tanaka Y, Schoenberger S, Altman A. Vav1/Rac-dependent actin cytoskeleton reorganization is required for lipid raft clustering in T cells. J Cell Biol 2001; 155:331-8. [PMID: 11684704 PMCID: PMC2150846 DOI: 10.1083/jcb.200107080] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Formation of the immunological synapse (IS) in T cells involves large scale molecular movements that are mediated, at least in part, by reorganization of the actin cytoskeleton. Various signaling proteins accumulate at the IS and are localized in specialized membrane microdomains, known as lipid rafts. We have shown previously that lipid rafts cluster and localize at the IS in antigen-stimulated T cells. Here, we provide evidence that lipid raft polarization to the IS depends on an intracellular pathway that involves Vav1, Rac, and actin cytoskeleton reorganization. Thus, lipid rafts did not translocate to the IS in Vav1-deficient (Vav1-/-) T cells upon antigen stimulation. Similarly, T cell receptor transgenic Jurkat T cells also failed to translocate lipid rafts to the IS when transfected with dominant negative Vav1 mutants. Raft polarization induced by membrane-bound cholera toxin cross-linking was also abolished in Jurkat T cells expressing dominant negative Vav1 or Rac mutants and in cells treated with inhibitors of actin polymerization. However, Vav overexpression that induced F-actin polymerization failed to induce lipid rafts clustering. Therefore, Vav is necessary, but not sufficient, to regulate lipid rafts clustering and polarization at the IS, suggesting that additional signals are required.
Collapse
Affiliation(s)
- M Villalba
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA
| | | | | | | | | | | |
Collapse
|
459
|
Vyas YM, Mehta KM, Morgan M, Maniar H, Butros L, Jung S, Burkhardt JK, Dupont B. Spatial organization of signal transduction molecules in the NK cell immune synapses during MHC class I-regulated noncytolytic and cytolytic interactions. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:4358-67. [PMID: 11591760 DOI: 10.4049/jimmunol.167.8.4358] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cytolytic activity of NK cells is tightly regulated by inhibitory receptors specific for MHC class I Ags. We have investigated the composition of signal transduction molecules in the supramolecular activation clusters in the MHC class I-regulated cytolytic and noncytolytic NK cell immune synapses. KIR2DL3-positive NK clones that are specifically inhibited in their cytotoxicity by HLA-Cw*0304 and polyclonal human NK cells were used for conjugate formation with target cells that are either protected or are susceptible to NK cell-mediated cytotoxicity. Polarization of talin, microtubule-organizing center, and lysosomes occurred only during cytolytic interactions. The NK immune synapses were analyzed by three-dimensional immunofluorescence microscopy, which showed two distinctly different synaptic organizations in NK cells during cytolytic and noncytolytic interactions. The center of a cytolytic synapse with MHC class I-deficient target is comprised of a complex of signaling molecules including Src homology (SH)2-containing protein tyrosine phosphatase-1 (SHP-1). Closely related molecules with overlapping functions, such as the Syk kinases, SYK, and ZAP-70, and adaptor molecules, SH2 domain-containing leukocyte protein of 76 kDa and B cell linker protein, are expressed in activated NK cells and are all recruited to the center of the cytolytic synapse. In contrast, the noncytolytic synapse contains SHP-1, but is lacking other components of the central supramolecular activation cluster. These findings indicate a functional role for SHP-1 in both the cytolytic and noncytolytic interactions. We also demonstrate, in three-cell conjugates, that a single NK cell forms a cytolytic synapse with a susceptible target cell in the presence of both susceptible and nonsusceptible target cells.
Collapse
Affiliation(s)
- Y M Vyas
- Immunology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | | | | | | | | | | | | | | |
Collapse
|
460
|
Revy P, Sospedra M, Barbour B, Trautmann A. Functional antigen-independent synapses formed between T cells and dendritic cells. Nat Immunol 2001; 2:925-31. [PMID: 11561183 DOI: 10.1038/ni713] [Citation(s) in RCA: 222] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Immunological synapse formation is usually assumed to require antigen recognition by T cell receptors. However, the immunological synapse formed at the interface between naïve T cells and dendritic cells (DCs) has never been described. We show here that in the absence of antigen, and even of major histocompatibility complex molecules, T cell-DC synapses are formed and lead to several T cell responses: a local increase in tyrosine phosphorylation, small Ca2+ responses, weak proliferation and long-term survival. These responses are triggered more readily in CD4+ T cells than in CD8+ T cells, which express a specific isoform of the repulsive molecule CD43. These phenomena may play a major role in the maintenance of the naïve T cell pool in vivo.
Collapse
Affiliation(s)
- P Revy
- Laboratoire d'Immuno-Pharmacologie Moléculaire, CNRS UPR415, Institut Cochin de Génétique Moléculaire, Paris, France
| | | | | | | |
Collapse
|
461
|
Wilde JI, Watson SP. Regulation of phospholipase C gamma isoforms in haematopoietic cells: why one, not the other? Cell Signal 2001; 13:691-701. [PMID: 11602179 DOI: 10.1016/s0898-6568(01)00191-7] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Phospholipase C gamma (PLCgamma) isoforms are critical for the generation of calcium signals in haematopoietic systems in response to the stimulation of immune receptors. PLCgamma is unique amongst phospholipases in that it is tightly regulated by the action of a number of tyrosine kinases. It is itself directly phosphorylated on a number of tyrosines and contains several domains through which it can interact with other signalling proteins and lipid products such as phosphatidylinositol 3,4,5-trisphosphate. Through this network of interactions, PLCgamma is activated and recruited to its substrate, phosphatidylinositol 4,5-bisphosphate, at the membrane. Both isoforms of PLCgamma, PLCgamma1 and PLCgamma2, are present in haematopoietic cells. The signalling cascade involved in the regulation of these two isoforms varies between cells, though the systems are similar for both PLCgamma1 and PLCgamma2. We will compare these cascades for both PLCgamma1 and PLCgamma2 and discuss possible reasons as to why one form of PLCgamma and not the other is required for signalling in specific haematopoietic cells, including T lymphocytes, B lymphocytes, platelets, and mast cells.
Collapse
Affiliation(s)
- J I Wilde
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | | |
Collapse
|
462
|
Abstract
T cell responses are altered in the aged in a manner usually interpreted as detrimental to host defences against infectious agents and possibly also against cancer. T cell dysregulation may be caused by any or a combination of stem cell deficits, compromised T cell differentiation, inefficient antigen processing and presentation by antigen presenting cells, suboptimal processing of the antigenic signal by T cells or inability of the T cell to respond appropriately thereafter. This review will focus on altered T cell signalling in ageing, encompassing not only alterations in signal transduction by the antigen-specific T cell receptor, but changes in the balance of positive and negative T cell costimulation and the resultant modified cytokine environment, the response to which is itself altered in ageing.
Collapse
Affiliation(s)
- G Pawelec
- Tübingen Ageing and Tumour Immunology Group, Second Department of Internal Medicine, University of Tübingen Medical School, Zentrum für Medizinsche Forschung, Waldhörnlestr. 22, D-72072, Tubingen, Germany.
| | | | | |
Collapse
|
463
|
Gelkop S, Babichev Y, Isakov N. T cell activation induces direct binding of the Crk adapter protein to the regulatory subunit of phosphatidylinositol 3-kinase (p85) via a complex mechanism involving the Cbl protein. J Biol Chem 2001; 276:36174-82. [PMID: 11418612 DOI: 10.1074/jbc.m100731200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Crk adapter proteins are assumed to play a role in T lymphocyte activation because of their induced association with tyrosine-phosphorylated proteins, such as ZAP-70 and Cbl, and with the phosphatidylinositol 3kinase regulatory subunit, p85, following engagement of the T cell antigen receptor. Although the exact mechanism of interaction between these molecules has not been fully defined, it has been generally accepted that Crk, ZAP-70, and p85 interact with tyrosine-phosphorylated Cbl, which serves as a major scaffold protein in activated T lymphocytes. Our present results demonstrate a cell activation-dependent reciprocal co-immunoprecipitation of CrkII and p85 from lysates of Jurkat T cells and a direct binding of CrkII to p85 in an overlay assay. The use of bead-immobilized GST fusion proteins indicated a complex mechanism of interaction between CrkII and p85 involving two distinct and mutually independent regions in each molecule. A relatively high affinity binding of the CrkII-SH3(N) domain to p85 and the p85-proline-B cell receptor-proline (PBP) region to CrkII was observed in lysates of either resting or activated T cells. Direct physical interaction between the CrkII-SH3(N) and the p85-PBP domain was demonstrated using recombinant fusion proteins and was further substantiated by binding competition studies. In addition, immobilized fusion proteins possessing the CrkII-SH2 and p85-SH3 domains were found to pull down p85 and CrkII, respectively, but only from lysates of activated T cells. Nevertheless, the GST-CrkII-SH2 fusion protein was unable to mediate direct association with p85 from lysates of either resting or activated T cells. Our results support a model in which T cell activation dependent conformational changes in CrkII and/or p85 promote an initial direct or indirect low affinity interaction between the two molecules, which is then stabilized by a secondary high affinity interaction mediated by direct binding of the CrkII-SH3(N) to the p85-PBP domain.
Collapse
Affiliation(s)
- S Gelkop
- Department of Microbiology and Immunology, Faculty of Health Sciences, and the Cancer Research Center, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | | | | |
Collapse
|
464
|
Affiliation(s)
- R N Germain
- Lymphocyte Biology Section, Laboratory of Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892, USA.
| |
Collapse
|
465
|
Abstract
Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by thrombocytopenia with small platelets, eczema, recurrent infections, autoimmune disorders, IgA nephropathy, and an increased incidence of hematopoietic malignancies. The identification of the responsible gene, WASP (Wiskott-Aldrich Syndrome Protein), revealed clinical heterogeneity of the syndrome, and showed that X-linked thrombocytopenia without, or with only mild immunodeficiency and eczema, is also caused by mutations of WASP. The study of WASP and its mutations demonstrates how a single gene defect can cause multiple and complex clinical symptoms.
Collapse
Affiliation(s)
- S Nonoyama
- Department of Pediatrics, School of Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
| | | |
Collapse
|
466
|
Latour S, Tanaka H, Demeure C, Mateo V, Rubio M, Brown EJ, Maliszewski C, Lindberg FP, Oldenborg A, Ullrich A, Delespesse G, Sarfati M. Bidirectional negative regulation of human T and dendritic cells by CD47 and its cognate receptor signal-regulator protein-alpha: down-regulation of IL-12 responsiveness and inhibition of dendritic cell activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2547-54. [PMID: 11509594 DOI: 10.4049/jimmunol.167.5.2547] [Citation(s) in RCA: 188] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Proinflammatory molecules, including IFN-gamma and IL-12, play a crucial role in the elimination of causative agents. To allow healing, potent anti-inflammatory processes are required to down-regulate the inflammatory response. In this study, we first show that CD47/integrin-associated protein, a ubiquitous multispan transmembrane protein highly expressed on T cells, interacts with signal-regulator protein (SIRP)-alpha, an immunoreceptor tyrosine-based inhibition motif-containing molecule selectively expressed on myelomonocytic cells, and next demonstrate that this pair of molecules negatively regulates human T and dendritic cell (DC) function. CD47 ligation by CD47 mAb or L-SIRP-alpha transfectants inhibits IL-12R expression and down-regulates IL-12 responsiveness of activated CD4(+) and CD8(+) adult T cells without affecting their response to IL-2. Human CD47-Fc fusion protein binds SIRP-alpha expressed on immature DC and mature DC. SIRP-alpha engagement by CD47-Fc prevents the phenotypic and functional maturation of immature DC and still inhibits cytokine production by mature DC. Finally, in allogeneic MLR between mDC and naive T cells, CD47-Fc decreases IFN-gamma production after priming and impairs the development of a Th1 response. Therefore, CD47 on T cells and its cognate receptor SIRP-alpha on DC define a novel regulatory pathway that may be involved in the maintenance of homeostasis by preventing the escalation of the inflammatory immune response.
Collapse
Affiliation(s)
- S Latour
- McGill Cancer Center, McGill University and Institut de Recherches Cliniques, Montréal, Québec, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
467
|
Shaffer AL, Rosenwald A, Hurt EM, Giltnane JM, Lam LT, Pickeral OK, Staudt LM. Signatures of the immune response. Immunity 2001; 15:375-85. [PMID: 11567628 DOI: 10.1016/s1074-7613(01)00194-7] [Citation(s) in RCA: 257] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A compendium of global gene expression measurements from DNA microarray analysis of immune cells identifies gene expression signatures defining various lineages, differentiation stages, and signaling pathways. Germinal center (GC) B cells represent a discrete stage of differentiation with a unique gene expression signature. This includes genes involved in proliferation, as evidenced by high expression of G2/M phase regulators and low expression of ribosomal and metabolic genes that are transcriptional targets of c-myc. GC B cells also lack expression of the NF-kappaB signature genes, which may favor apoptosis. Finally, the transcriptional repression signature of BCL-6 reveals how this factor can prevent terminal differentiation of B cells and cause B cell lymphomas.
Collapse
Affiliation(s)
- A L Shaffer
- Metabolism Branch, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Building 10, Room 4N114, Bethesda, MD 20892, USA
| | | | | | | | | | | | | |
Collapse
|
468
|
Westerberg L, Greicius G, Snapper SB, Aspenström P, Severinson E. Cdc42, Rac1, and the Wiskott-Aldrich syndrome protein are involved in the cytoskeletal regulation of B lymphocytes. Blood 2001; 98:1086-94. [PMID: 11493455 DOI: 10.1182/blood.v98.4.1086] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Patients with the immunodeficiency disorder Wiskott-Aldrich syndrome (WAS) have lymphocytes with aberrant microvilli, and their T cells, macrophages, and dendritic cells are impaired in cytoskeletal-dependent processes. WAS is caused by a defective or a missing WAS protein (WASP). Signal mediators interleukin-4 (IL-4) and CD40 are important for actin-dependent morphology changes in B cells. A possible function of WASP and its interacting partners, Cdc42 and Rac1, was investigated for these changes. It was found that active Cdc42 and Rac1 induced filopodia and lamellipodia, respectively, in activated B cells. Evidence is given that IL-4 has a specific role in the regulated cycling of Cdc42 because IL-4 partially and transiently depleted active Cdc42 from detergent extract of activated B cells. WASP-deficient B lymphocytes were impaired in IL-4-- and CD40-dependent induction of polarized and spread cells. Microvilli were expressed on WASP-deficient B cells, but they appeared shorter and less dense in cell contacts than in wild-type cells. In conclusion, evidence is provided for the involvement of Cdc42, Rac1, and WASP in the cytoskeletal regulation of B lymphocytes. Aberrations in WASP-deficient B lymphocytes, described here, provide further evidence that WAS is a cytoskeletal disease of hematopoietic cells. (Blood. 2001;98:1086-1094)
Collapse
Affiliation(s)
- L Westerberg
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | |
Collapse
|
469
|
Affiliation(s)
- A Lanzavecchia
- Institute for Research in Biomedicine, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland.
| | | |
Collapse
|
470
|
Bromley SK, Burack WR, Johnson KG, Somersalo K, Sims TN, Sumen C, Davis MM, Shaw AS, Allen PM, Dustin ML. The immunological synapse. Annu Rev Immunol 2001; 19:375-96. [PMID: 11244041 DOI: 10.1146/annurev.immunol.19.1.375] [Citation(s) in RCA: 661] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The adaptive immune response is initiated by the interaction of T cell antigen receptors with major histocompatibility complex molecule-peptide complexes in the nanometer scale gap between a T cell and an antigen-presenting cell, referred to as an immunological synapse. In this review we focus on the concept of immunological synapse formation as it relates to membrane structure, T cell polarity, signaling pathways, and the antigen-presenting cell. Membrane domains provide an organizational principle for compartmentalization within the immunological synapse. T cell polarization by chemokines increases T cell sensitivity to antigen. The current model is that signaling and formation of the immunological synapse are tightly interwoven in mature T cells. We also extend this model to natural killer cell activation, where the inhibitory NK synapse provides a striking example in which inhibition of signaling leaves the synapse in its nascent, inverted state. The APC may also play an active role in immunological synapse formation, particularly for activation of naïve T cells.
Collapse
MESH Headings
- Animals
- Antigen Presentation/immunology
- Cell Adhesion
- Cell Adhesion Molecules/physiology
- Cell Communication
- Cell Membrane/ultrastructure
- Cell Polarity
- Chemokines/physiology
- Cholera Toxin/pharmacology
- Immunologic Capping
- Killer Cells, Natural/immunology
- Killer Cells, Natural/ultrastructure
- Lymphocyte Activation/immunology
- Membrane Microdomains/physiology
- Membrane Microdomains/ultrastructure
- Mice
- Models, Immunological
- Receptor-CD3 Complex, Antigen, T-Cell/immunology
- Receptor-CD3 Complex, Antigen, T-Cell/ultrastructure
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/ultrastructure
- Receptors, Chemokine/physiology
- Receptors, Immunologic/immunology
- Receptors, Immunologic/physiology
- Receptors, Immunologic/ultrastructure
- Signal Transduction
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/ultrastructure
Collapse
Affiliation(s)
- S K Bromley
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, Missouri 63110, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
471
|
Warren HS, Campbell AJ, Waldron JC, Lanier LL. Biphasic response of NK cells expressing both activating and inhibitory killer Ig-like receptors. Int Immunol 2001; 13:1043-52. [PMID: 11470774 DOI: 10.1093/intimm/13.8.1043] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
NK cells can co-express inhibitory and activating killer Ig-like receptors (KIR) recognizing the same HLA class I ligand. We present evidence from experiments with NK cells expressing both activating (KIR2DS2) and inhibitory (KIR2DL2 and KIR2DL3) receptors that the activating KIR can function without apparent interference from the inhibitory KIR. These studies used CD158b mAb that is equally reactive with KIR2DS2, KIR2DL2 and KIR2DL3. First, we show using plastic-immobilized CD158b mAb that the activating KIR2DS2 is stimulated, resulting in NK cell division and degranulation. Second, we show using soluble CD158b mAb and FcRII (+) P815 cells that high concentrations of CD158b mAb trigger the inhibitory KIR, whereas low concentrations stimulate the activating KIR2DS2 resulting in NK cell division and cytolysis. These results demonstrate that the activating KIR2DS2 can function on cells co-expressing the inhibitory KIR2DL2 and/or KIR2DL3, indicating the potential for independent function of activating KIR with natural ligand.
Collapse
MESH Headings
- Animals
- Antibodies, Monoclonal/metabolism
- Antigens, CD/immunology
- Binding Sites, Antibody
- Cell Degranulation/immunology
- Cell Division/immunology
- Cell Line
- Cytotoxicity Tests, Immunologic/methods
- Humans
- Immunoglobulin G/immunology
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lymphocyte Activation/immunology
- Lymphocyte Subsets/immunology
- Lymphocyte Subsets/metabolism
- Mice
- Plastics/metabolism
- Receptors, IgG/biosynthesis
- Receptors, IgG/immunology
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/immunology
- Receptors, Immunologic/physiology
- Receptors, KIR
- Receptors, KIR2DL2
- Receptors, KIR2DL3
- Sarcoma, Experimental
- Solubility
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- H S Warren
- Cancer Research Unit, The Canberra Hospital, Canberra, ACT 2606, Australia
| | | | | | | |
Collapse
|
472
|
Donnadieu E, Revy P, Trautmann A. Imaging T-cell antigen recognition and comparing immunological and neuronal synapses. Immunology 2001; 103:417-25. [PMID: 11529931 PMCID: PMC1783261 DOI: 10.1046/j.1365-2567.2001.01268.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2001] [Accepted: 04/27/2001] [Indexed: 12/15/2022] Open
Affiliation(s)
- E Donnadieu
- Laboratoire d'Immuno-Pharmacologie, CNRS UPR 415, ICGM, 22 rue Méchain, 75014 Paris, France
| | | | | |
Collapse
|
473
|
Abstract
The T cell and antigen-presenting cell communicate to initiate an immune response through formation of an immunological synapse. This specialized cell-cell junction is compartmentalized into adhesion molecule and T cell receptor enriched regions or SMACs. Distinct signals seem to be generated in the T cell receptor and adhesion molecule-dominated regions. This review focuses on how these distinct signaling pathways may be integrated within the T cell to set thresholds for T cell activation, proliferation, and survival.
Collapse
Affiliation(s)
- M L Dustin
- Department of Pathology, Skirball Institute of Molecular Medicine, New York University School of Medicine, New York 10016, USA.
| |
Collapse
|
474
|
Svensson C, Lundberg K. Immune-specific up-regulation of adseverin gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin. Mol Pharmacol 2001; 60:135-42. [PMID: 11408608 DOI: 10.1124/mol.60.1.135] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To identify genes that are regulated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and possibly involved in TCDD-induced immunotoxicity, we used the differential display technique to screen for differentially expressed genes in the mouse thymus. Here we show that TCDD increased the expression of adseverin, a Ca(2+)-dependent, actin-severing protein. The induction of adseverin is dose- and time-dependent in parallel with the induction of CYP1A1, which is currently the most frequently used marker for TCDD exposure. A comparison between mouse strains with different TCDD responsiveness indicated that the induction of adseverin is dependent on the aryl hydrocarbon receptor, a transcription factor known to mediate most of TCDD's biological effects. Examination of additional organs revealed that the up-regulation of the adseverin gene expression is immune-specific. Using an anti-adseverin antibody, we confirmed the induction of adseverin by TCDD at the protein level and it was confined to the thymic cortex, which harbors immature thymocytes that are known target cells of TCDD. Considering adseverin's role in actin cytoskeletal reorganization, our observations reveal new mechanistic aspects of how TCDD might exert some of its immunotoxic effects.
Collapse
Affiliation(s)
- C Svensson
- Department of Pharmaceutical Biosciences, Division of Toxicology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | | |
Collapse
|
475
|
Doody GM, Bell SE, Vigorito E, Clayton E, McAdam S, Tooze R, Fernandez C, Lee IJ, Turner M. Signal transduction through Vav-2 participates in humoral immune responses and B cell maturation. Nat Immunol 2001; 2:542-7. [PMID: 11376342 DOI: 10.1038/88748] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
B and T lymphocytes develop normally in mice lacking the guanine nucleotide exchange factor Vav-2. However, the immune responses to type II thymus-independent antigen as well as the primary response to thymus-dependent (TD) antigen are defective. Vav-2-deficient mice are also defective in their ability to switch immunoglobulin class, form germinal centers and generate secondary immune responses to TD antigens. Mice lacking both Vav-1 and Vav-2 contain reduced numbers of B lymphocytes and display a maturational block in the development of mature B cells. B cells from Vav-1(-/-)Vav-2(-/-) mice respond poorly to antigen receptor triggering, both in terms of proliferation and calcium release. These studies show the importance of Vav-2 in humoral immune responses and B cell maturation.
Collapse
Affiliation(s)
- G M Doody
- Laboratory of Lymphocyte Signaling and Development, Molecular Immunology Programme, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
476
|
Lanzavecchia A, Sallusto F. Antigen decoding by T lymphocytes: from synapses to fate determination. Nat Immunol 2001; 2:487-92. [PMID: 11376334 DOI: 10.1038/88678] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Naïve T lymphocytes sense foreign antigens by establishing contacts with dendritic cells (DCs). At the immunological synapse between the T cell and a DC, T cell receptors (TCRs) are serially engaged and triggered by specific ligands. The amount and duration of TCR triggering and the efficiency of signal amplification determine T cell commitment to proliferation and differentiation. The nature and availability of DCs bearing antigen and costimulatory molecules shape the T cell response, giving rise to distinct functional outputs such as effector and memory T cell generation or T cell tolerance.
Collapse
Affiliation(s)
- A Lanzavecchia
- Institute for Research in Biomedicine, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland.
| | | |
Collapse
|
477
|
Qi SY, Groves JT, Chakraborty AK. Synaptic pattern formation during cellular recognition. Proc Natl Acad Sci U S A 2001; 98:6548-53. [PMID: 11371622 PMCID: PMC34390 DOI: 10.1073/pnas.111536798] [Citation(s) in RCA: 285] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2000] [Indexed: 11/18/2022] Open
Abstract
Cell-cell recognition often requires the formation of a highly organized pattern of receptor proteins (a synapse) in the intercellular junction. Recent experiments [e.g., Monks, C. R. F., Freiberg, B. A., Kupfer, H., Sciaky, N. & Kupfer, A. (1998) Nature (London) 395, 82-86; Grakoui, A., Bromley, S. K., Sumen, C., Davis, M. M., Shaw, A. S., Allen, P. M. & Dustin, M. L. (1999) Science 285, 221-227; and Davis, D. M., Chiu, I., Fassett, M., Cohen, G. B., Mandelboim, O. & Strominger, J. L. (1999) Proc. Natl. Acad. Sci. USA 96, 15062-15067] vividly demonstrate a complex evolution of cell shape and spatial receptor-ligand patterns (several microns in size) in the intercellular junction during immunological synapse formation. The current view is that this dynamic rearrangement of proteins into organized supramolecular activation clusters is driven primarily by active cytoskeletal processes [e.g., Dustin, M. L. & Cooper, J. A. (2000) Nat. Immunol. 1, 23-29; and Wulfing, C. & Davis, M. M. (1998) Science 282, 2266-2269]. Here, aided by a quantitative analysis of the relevant physico-chemical processes, we demonstrate that the essential characteristics of synaptic patterns observed in living cells can result from spontaneous self-assembly processes. Active cellular interventions are superimposed on these self-organizing tendencies and may also serve to regulate the spontaneous processes. We find that the protein binding/dissociation characteristics, protein mobilities, and membrane constraints measured in the cellular environment are delicately balanced such that the length and time scales of spontaneously evolving patterns are in near-quantitative agreement with observations for synapse formation between T cells and supported membranes [Grakoui, A., Bromley, S. K., Sumen, C., Davis, M. M., Shaw, A. S., Allen, P. M. & Dustin, M. L. (1999) Science 285, 221-227]. The model we present provides a common way of analyzing immunological synapse formation in disparate systems (e.g., T cell/antigen-presenting cell junctions with different MHC-peptides, natural killer cells, etc.).
Collapse
Affiliation(s)
- S Y Qi
- Departments of Chemical Engineering and Chemistry, Physical Biosciences Division, Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
478
|
Woods ML, Shimizu Y. Signaling networks regulating β1 integrin‐mediated adhesion of T lymphocytes to extracellular matrix. J Leukoc Biol 2001. [DOI: 10.1189/jlb.69.6.874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Melody L. Woods
- Department of Laboratory Medicine and Pathology, Center for Immunology, Cancer Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Yoji Shimizu
- Department of Laboratory Medicine and Pathology, Center for Immunology, Cancer Center, University of Minnesota Medical School, Minneapolis, Minnesota
| |
Collapse
|
479
|
Dustin ML, de Fougerolles AR. Reprogramming T cells: the role of extracellular matrix in coordination of T cell activation and migration. Curr Opin Immunol 2001; 13:286-90. [PMID: 11406359 DOI: 10.1016/s0952-7915(00)00217-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The stable immunological synapse between a T cell and antigen-presenting cell coordinates migration and activation. Three-dimensional collagen gels transform this interaction into a series of transient hit-and-run encounters. Here we integrate these alternative modes of interaction in a model for primary T cell activation and effector function in vivo.
Collapse
Affiliation(s)
- M L Dustin
- The Molecular Pathogenesis Program, Skirball Institute of Molecular Medicine and the Department of Pathology, New York University School of Medicine, 540 First Avenue, 10016, New York, NY, USA.
| | | |
Collapse
|
480
|
Payrastre B, Missy K, Giuriato S, Bodin S, Plantavid M, Gratacap M. Phosphoinositides: key players in cell signalling, in time and space. Cell Signal 2001; 13:377-87. [PMID: 11384836 DOI: 10.1016/s0898-6568(01)00158-9] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Over the last few years, many reports have extended our knowledge of the inositol lipid metabolism and brought out some exciting information about the location, the variety and the role of phosphoinositides (PIs). Besides the so-called "canonical PI pathway" leading to the production of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2), the precursor of the intracellular second messengers inositol 1,4,5-trisphosphate and diacylglycerol (DAG), many other metabolic pathways have been identified to produce seven different polyphosphoinositides. Several of these quantitatively minor lipid molecules appear to be specifically involved in the control of cellular events, such as the spatial and temporal organisation of key signalling pathways, the rearrangement of the actin cytoskeleton or the intracellular vesicle trafficking. This is consistent with the fact that many of the enzymes, such as kinases and phosphatases, involved in the tight control of the intracellular level of polyphosphoinositides, are regulated and/or relocated through cell surface receptors for extracellular ligands. The remarkable feature of PIs, which can be rapidly synthesised and degraded in discrete membrane domains or even subnuclear structures, places them as ideal regulators and integrators of very dynamic mechanisms of cell regulation. In this review, we will summarise recent studies on the potential location, the metabolic pathways and the role of the different PIs. Some aspects of the temporal synthesis of D3 PIs will also be discussed.
Collapse
Affiliation(s)
- B Payrastre
- INSERM U326, Hôpital Purpan, IFR 30, 31059, Toulouse, France.
| | | | | | | | | | | |
Collapse
|
481
|
Volkov Y, Long A, McGrath S, Ni Eidhin D, Kelleher D. Crucial importance of PKC-β(I) in LFA-1–mediated locomotion of activated T cells. Nat Immunol 2001; 2:508-14. [PMID: 11376337 DOI: 10.1038/88700] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Crawling T cell locomotion in which activated lymphocyte function-associated antigen 1 (LFA-1) integrins participate is associated with translocation of the protein kinase C-beta (PKC-beta) isoenzyme to the microtubule cytoskeleton. In normal T cells and T lymphoma cell lines, this type of motility is accompanied by PKC-beta-sensitive cytoskeletal rearrangements and the formation of trailing cell extensions, which are supported by microtubules. Expression of PKC-beta(I) and enhanced green fluorescent protein (EGFP) in nonmotile PKC-beta-deficient T cells restored their locomotory behavior in response to a triggering stimulus delivered via LFA-1 and correlated directly with the degree of cell polarization. We have also shown that PKC-beta(I) is a component of the tubulin-enriched LFA-1-cytoskeletal complex assembled upon LFA-1 cross-linking. These observations may have physiological equivalents at advanced (post-integrin activation) stages of lymphocyte extravasation.
Collapse
Affiliation(s)
- Y Volkov
- Dublin Molecular Medicine Centre, Trinity College, Dublin 8, Ireland.
| | | | | | | | | |
Collapse
|
482
|
Alfsen A, Iniguez P, Bouguyon E, Bomsel M. Secretory IgA specific for a conserved epitope on gp41 envelope glycoprotein inhibits epithelial transcytosis of HIV-1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:6257-65. [PMID: 11342649 DOI: 10.4049/jimmunol.166.10.6257] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
As one of the initial mucosal transmission pathways of HIV (HIV-1), epithelial cells translocate HIV-1 from apical to basolateral surface by nondegradative transcytosis. Transcytosis is initiated when HIV-1 envelope glycoproteins bind to the epithelial cell membrane. Here we show that the transmembrane gp41 subunit of the viral envelope binds to the epithelial glycosphingolipid galactosyl ceramide (Gal Cer), an alternative receptor for HIV-1, at a site involving the conserved ELDKWA epitope. Disrupting the raft organization of the Gal Cer-containing microdomains at the apical surface inhibited HIV-1 transcytosis. Immunological studies confirmed the critical role of the conserved ELDKWA hexapeptide in HIV-1 transcytosis. Mucosal IgA, but not IgG, from seropositive subjects targeted the conserved peptide, neutralized gp41 binding to Gal Cer, and blocked HIV-1 transcytosis. These results underscore the important role of secretory IgA in designing strategies for mucosal protection against HIV-1 infection.
Collapse
Affiliation(s)
- A Alfsen
- Institut National de la Santé et de la Recherche Médicale, Unité 332, Institut Cochin de Genetique Moleculaire, Paris, France
| | | | | | | |
Collapse
|
483
|
Lafont V, Liautard J, Sable-Teychene M, Sainte-Marie Y, Favero J. Isopentenyl pyrophosphate, a mycobacterial non-peptidic antigen, triggers delayed and highly sustained signaling in human gamma delta T lymphocytes without inducing eown-modulation of T cell antigen receptor. J Biol Chem 2001; 276:15961-7. [PMID: 11278429 DOI: 10.1074/jbc.m008684200] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Vgamma9Vdelta2 T cell subset, which represents up to 90% of the circulating gammadelta T cells in humans, was shown to be activated, via the T cell receptor (TcR), by non-peptidic phosphorylated small organic molecules. These phosphoantigens, which are not presented by professional antigen-presenting cells, induce production of high amounts of interferon-gamma and tumor necrosis factor (TNF-alpha). To date, the specific signals triggered by these antigens have not been characterized. Here we analyze proximal and later intracellular signals triggered by isopentenyl pyrophosphate (IPP), a mycobacterial antigen that specifically stimulates Vgamma9Vdelta2 T cells, and compare these to signals induced by the non-physiological model using an anti-CD3 antibody. During antigenic stimulation we noticed that, except for the proximal p56(lck) signal, which is triggered early, the signals appear to be delayed and highly sustained. This delay, which likely accounts for the delay observed in TNF-alpha production, is discussed in terms of the ability of the antigen to cross-link and recruit transducing molecules mostly anchored to lipid rafts. Moreover, we demonstrate that, in contrast to anti-CD3 antibody, IPP does not induce down-modulation of the TcR.CD3 complex, which likely results in the highly sustained signaling and release of high levels of TNF-alpha.
Collapse
MESH Headings
- Antigens, Bacterial/pharmacology
- Cells, Cultured
- Down-Regulation/drug effects
- Hemiterpenes
- Humans
- Kinetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/metabolism
- Mycobacterium/immunology
- Organophosphorus Compounds/pharmacology
- Phosphorylation
- Protein-Tyrosine Kinases/metabolism
- Receptors, Antigen, T-Cell/drug effects
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell, gamma-delta/drug effects
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Signal Transduction/drug effects
- Signal Transduction/immunology
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- Tumor Necrosis Factor-alpha/biosynthesis
- ZAP-70 Protein-Tyrosine Kinase
Collapse
Affiliation(s)
- V Lafont
- INSERM U431, Microbiologie et Pathologie Cellulaire Infectieuse, Université Montpellier 2, Place Eugène Bataillon, cc 100, Montpellier 34095, cedex 5, France
| | | | | | | | | |
Collapse
|
484
|
Cochran JR, Aivazian D, Cameron TO, Stern LJ. Receptor clustering and transmembrane signaling in T cells. Trends Biochem Sci 2001; 26:304-10. [PMID: 11343923 DOI: 10.1016/s0968-0004(01)01815-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
T cells are activated via engagement of their cell-surface receptors with molecules of the major histocompatibility complex (MHC) displayed on another cell surface. This process, which is a key step in the recognition of foreign antigens by the immune system, involves oligomerization of receptor components. Recent characterization of the T-cell response to soluble arrays of MHC-peptide complexes has provided insights into the triggering mechanism for T-cell activation.
Collapse
Affiliation(s)
- J R Cochran
- Dept of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | |
Collapse
|
485
|
Hwang I, Sprent J. Role of the actin cytoskeleton in T cell absorption and internalization of ligands from APC. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:5099-107. [PMID: 11290791 DOI: 10.4049/jimmunol.166.8.5099] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A feature of T-APC interaction is that, via either TCR or CD28, T cells can absorb molecules from APC on to the cell surface and then internalize these molecules. Here, using both normal and TCR-transgenic T cells, we investigated the mechanism of T cell absorption of molecules from APC and the role of the cytoskeleton. The results show that although activated T cells could absorb APC molecules in the form of cell fragments, uptake of molecules by resting T cells required direct T-APC interaction. Based on studies with latrunculin B, surface absorption of molecules by resting T cells was crucially dependent upon the actin cytoskeleton for both CD28- and TCR-mediated absorption. Significantly, however, TCR-mediated absorption became strongly resistant to latrunculin B when the concentration of MHC-bound peptide on APC was raised to a high level, implying that the actin cytoskeleton is only important for absorption when the density of receptor/ligand interaction is low. By contrast, in all situations tested, the actin cytoskeleton played a decisive role in controlling T cell internalization of ligands from the cell surface.
Collapse
Affiliation(s)
- I Hwang
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | |
Collapse
|
486
|
van Spriel AB, Leusen JH, van Egmond M, Dijkman HB, Assmann KJ, Mayadas TN, van de Winkel JG. Mac-1 (CD11b/CD18) is essential for Fc receptor-mediated neutrophil cytotoxicity and immunologic synapse formation. Blood 2001; 97:2478-86. [PMID: 11290613 DOI: 10.1182/blood.v97.8.2478] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Receptors for human immunoglobulin (Ig)G and IgA initiate potent cytolysis of antibody (Ab)-coated targets by polymorphonuclear leukocytes (PMNs). Mac-1 (complement receptor type 3, CD11b/CD18) has previously been implicated in receptor cooperation with Fc receptors (FcRs). The role of Mac-1 in FcR-mediated lysis of tumor cells was characterized by studying normal human PMNs, Mac-1-deficient mouse PMNs, and mouse PMNs transgenic for human FcR. All PMNs efficiently phagocytosed Ab-coated particles. However, antibody-dependent cellular cytotoxicity (ADCC) was abrogated in Mac-1(-/-) PMNs and in human PMNs blocked with anti-Mac-1 monoclonal Ab (mAb). Mac-1(-/-) PMNs were unable to spread on Ab-opsonized target cells and other Ab-coated surfaces. Confocal laser scanning and electron microscopy revealed a striking difference in immunologic synapse formation between Mac-1(-/-) and wild-type PMNs. Also, respiratory burst activity could be measured outside membrane-enclosed compartments by using Mac-1(-/-) PMNs bound to Ab-coated tumor cells, in contrast to wild-type PMNs. In summary, these data document an absolute requirement of Mac-1 for FcR-mediated PMN cytotoxicity toward tumor targets. Mac-1(-/-) PMNs exhibit defective spreading on Ab-coated targets, impaired formation of immunologic synapses, and absent tumor cytolysis.
Collapse
Affiliation(s)
- A B van Spriel
- Immunotherapy Laboratory and Medarex Europe, University Medical Center Utrecht, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
487
|
Abstract
Productive T cell activation depends on the assembly of a highly ordered and compartmentalized immunological synapse or supramolecular activation complex (SMAC). Reorganization of the actin cytoskeleton and clustering of specialized membrane microdomains, or lipid rafts, occur early following TCR/CD3 and costimulatory receptor ligation. Many key signaling molecules localize in lipid raft patches during T cell activation. Lipid raft reorganization is required for T cell activation, where it plays an apparently important role in stabilizing the T cell synapse. Here we review recent evidence supporting the role of lipid rafts in T cell activation. Particular emphasis is placed on the coupling of protein kinase C-theta(PKCtheta), which is selectively expressed in T cells and is known to function as an essential signal for T cell activation, and lipid rafts.
Collapse
Affiliation(s)
- K Bi
- Division of Cell Biology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA
| | | |
Collapse
|
488
|
Abstract
Primary immune responses are initiated by specific physical interaction of antigen-specific T cells and professional antigen-presenting cells (APCs). Productive interactions can be a dynamic process that combines physical T-cell binding to APCs with vigorous crawling across and scanning of the APC surface, resulting in signal induction. After T-cell detachment, subsequent migratory contacts to the same or neighboring dendritic cells (DCs) allow the accumulation of sequential signals and interaction time. Here, we develop a serial encounter model of T-cell activation and discuss how the summation of multiple signals provides an efficient strategy to control an ongoing immune response.
Collapse
Affiliation(s)
- P Friedl
- Cell Migration Laboratory, Dept of Dermatology, University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany.
| | | |
Collapse
|
489
|
Krawczyk C, Penninger JM. Molecular motors involved in T cell receptor clusterings. J Leukoc Biol 2001. [DOI: 10.1189/jlb.69.3.317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Connie Krawczyk
- Amgen Institute/Ontario Cancer Institute, Departments of Medical Biophysics and Immunology, University of Toronto, Ontario, Canada
| | - Josef M. Penninger
- Amgen Institute/Ontario Cancer Institute, Departments of Medical Biophysics and Immunology, University of Toronto, Ontario, Canada
| |
Collapse
|
490
|
Bunnell SC, Kapoor V, Trible RP, Zhang W, Samelson LE. Dynamic actin polymerization drives T cell receptor-induced spreading: a role for the signal transduction adaptor LAT. Immunity 2001; 14:315-29. [PMID: 11290340 DOI: 10.1016/s1074-7613(01)00112-1] [Citation(s) in RCA: 338] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
T cell activation induces functional changes in cell shape and cytoskeletal architecture. To facilitate the collection of dynamic, high-resolution images of activated T cells, we plated T cells on coverslips coated with antibodies to the T cell receptor (TCR). Using these images, we were able to quantitate the morphological responses of individual cells over time. Here, we show that TCR engagement triggers the formation and expansion of contacts bounded by continuously remodeled actin-rich rings. These processes are associated with the extension of lamellipodia and require actin polymerization, tyrosine kinase activation, cytoplasmic calcium increases, and LAT, an important hematopoietic adaptor. In addition, the maintenance of the resulting contact requires sustained calcium influxes, an intact microtubule cytoskeleton, and functional LAT.
Collapse
Affiliation(s)
- S C Bunnell
- Laboratory of Cellular and Molecular Biology, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892, USA
| | | | | | | | | |
Collapse
|
491
|
Devriendt K, Kim AS, Mathijs G, Frints SG, Schwartz M, Van Den Oord JJ, Verhoef GE, Boogaerts MA, Fryns JP, You D, Rosen MK, Vandenberghe P. Constitutively activating mutation in WASP causes X-linked severe congenital neutropenia. Nat Genet 2001; 27:313-7. [PMID: 11242115 DOI: 10.1038/85886] [Citation(s) in RCA: 289] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Wiskott-Aldrich syndrome protein (WASP; encoded by the gene WAS) and its homologs are important regulators of the actin cytoskeleton, mediating communication between Rho-family GTPases and the actin nucleation/crosslinking factor, the Arp2/3 complex. Many WAS mutations impair cytoskeletal control in hematopoietic tissues, resulting in functional and developmental defects that define the X-linked Wiskott-Aldrich syndrome (WAS) and the related X-linked thrombocytopenia (XLT). These diseases seem to result from reduced WASP signaling, often through decreased transcription or translation of the gene. Here we describe a new disease, X-linked severe congenital neutropenia (XLN), caused by a novel L270P mutation in the region of WAS encoding the conserved GTPase binding domain (GBD). In vitro, the mutant protein is constitutively activated through disruption of an autoinhibitory domain in the wild-type protein, indicating that loss of WASP autoinhibition is a key event in XLN. Our findings highlight the importance of precise regulation of WASP in hematopoietic development and function, as impairment versus enhancement of its activity give rise to distinct spectra of cellular defects and clinical phenotypes.
Collapse
Affiliation(s)
- K Devriendt
- Centre for Human Genetics, University Hospital Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
492
|
Suga K, Katagiri K, Kinashi T, Harazaki M, Iizuka T, Hattori M, Minato N. CD98 induces LFA-1-mediated cell adhesion in lymphoid cells via activation of Rap1. FEBS Lett 2001; 489:249-53. [PMID: 11165259 DOI: 10.1016/s0014-5793(00)02222-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CD98 is a multifunctional heterodimeric membrane protein involved in the regulation of cell adhesion as well as amino acid transport. We show that CD98 cross-linking persistently activates Rap1 GTPase in a LFA-1-dependent manner and induces LFA-1/ICAM-1-mediated cell adhesion in lymphocytes. Specific phosphatidylinositol-3-kinase (PI3K) inhibitors suppressed both LFA-1 activation and Rap1GTP generation, and abrogation of Rap1GTP by retroviral over-expression of a specific Rap1 GTPase activating protein, SPA-1, totally inhibited the LFA-1/ICAM-1-mediated cell adhesion. These results suggest that CD98 cross-linking activates LFA-1 via the PI3K signaling pathway and induces accumulation of Rap1GTP in a LFA-1-dependent manner, which in turn mediates the cytoskeleton-dependent cell adhesion process.
Collapse
Affiliation(s)
- K Suga
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Japan
| | | | | | | | | | | | | |
Collapse
|
493
|
|
494
|
Al-Alwan MM, Rowden G, Lee TD, West KA. The dendritic cell cytoskeleton is critical for the formation of the immunological synapse. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1452-6. [PMID: 11160183 DOI: 10.4049/jimmunol.166.3.1452] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The binding of a T cell to an APC results in T cell actin cytoskeletal rearrangement leading to the formation of an immunological synapse. The APC cytoskeleton has been thought to play a passive role in this process. In this study, we demonstrate that dendritic cells (DC), unlike other APC, actively polarize their actin cytoskeleton during interaction with T cells. DC cytoskeletal rearrangement was critical for both the clustering and the activation of resting T cells. This study provides compelling evidence that the APC cytoskeleton plays an active role in the immunological synapse and may explain the unique ability of DC to activate resting T cells.
Collapse
Affiliation(s)
- M M Al-Alwan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | | | | |
Collapse
|
495
|
Tsoukas CD, Grasis JA, Ching KA, Kawakami Y, Kawakami T. Itk/Emt: a link between T cell antigen receptor-mediated Ca2+ events and cytoskeletal reorganization. Trends Immunol 2001; 22:17-20. [PMID: 11286686 DOI: 10.1016/s1471-4906(00)01795-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Itk/Emt, a tec family tyrosine kinase, is important for T-cell development and activation through the antigen receptor. Here, we review data suggesting that Itk/Emt is involved in the generation of critical second messengers (Ca(2+), PKC) whose duration it modulates by regulation of cytoskeletal reorganization. We propose that Itk/Emt constitutes an important link between these critical signaling events.
Collapse
Affiliation(s)
- C D Tsoukas
- Department of Biology and the Molecular Biology Institute, San Diego State University, CA 92182, USA.
| | | | | | | | | |
Collapse
|
496
|
Abstract
The germinal center reaction is one critical outcome of helper T-cell-dependent antigen-specific B-cell responses. Germinal center reactions are the culmination of an orchestrated series of intercellular information exchanges discussed here as the serial synapsis model of adaptive immunity. The main purpose of the germinal center reaction is the development of B-cell memory through iterative cycles of somatic antigen receptor diversification and the selection of B cells with receptors of best fit. Recent studies provide insight into the regulation of these complex processes in vivo with new information on the cellular organization of the memory B-cell compartment.
Collapse
Affiliation(s)
- L J McHeyzer-Williams
- Duke University Medical Center, Department of Immunology, Durham, North Carolina 27710, USA.
| | | | | |
Collapse
|
497
|
Abstract
T-cell recognition and activation occurs within a specialized area of contact known as the immunologic synapse, localized to areas of glycolipid-enriched membrane microdomains. Within this area, T-cell activation is dependent not only upon specific recognition of peptide antigen embedded within molecules of the major histocompatibility complex, but also on a variety of costimulatory receptors and interactions. Engagement of T-cell receptor (TCR) with antigen alone will induce T-cell unresponsiveness; ligation of the coreceptor CD28 will prevent the induction of unresponsiveness. Novel costimulatory molecules belonging to both the CD28 and TNF/TNFR superfamilies have recently been identified. These receptors appear to act at different stages of T-cell differentiation and activation, have been shown to play a role in promoting different T-cell effector functions, and are important for B-cell differentiation and function.
Collapse
Affiliation(s)
- L I Salazar-Fontana
- Laboratory of Lymphocyte Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | |
Collapse
|
498
|
Abstract
Antigen-specific activation of T lymphocytes requires the interaction of their clonally distributed T-cell receptors with plasma membrane ligands composed of foreign peptide antigens bound to major histocompatibility complex molecules. For proliferation and differentiation to ensue, a variety of other adhesive and accessory proteins must also interact with their counter-receptors on the antigen-presenting cell to facilitate and complement the T-cell receptor-antigen recognition event. Recent studies have revealed that these various proteins show an unexpected degree of spatial organization in the zone of cell-cell contact. This region of membrane approximation is now referred to as the "immunological synapse" because of its functional analogy to the site of intercellular information transfer between neurons. Here, we review the evidence for signaling-dependent control of the dynamic changes in protein distribution that gives rise to the synapse and try to relate the emerging spatio-temporal information on synapse formation to T-cell biology.
Collapse
Affiliation(s)
- J Delon
- Lymphocyte Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | |
Collapse
|
499
|
Kruisbeek AM, Haks MC, Carleton M, Michie AM, Zúñiga-Pflücker JC, Wiest DL. Branching out to gain control: how the pre-TCR is linked to multiple functions. IMMUNOLOGY TODAY 2000; 21:637-44. [PMID: 11114425 DOI: 10.1016/s0167-5699(00)01744-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
How is signaling specificity achieved by the pre-TCR during selection of T-cell fate? Like the TCR, this receptor controls many functions, and recent studies define which pathways couple the pre-TCR to the molecular events controlling survival, proliferation, allelic exclusion at the TCRbeta locus, and further differentiation.
Collapse
Affiliation(s)
- A M Kruisbeek
- Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
500
|
Affiliation(s)
- M L Dustin
- Center for Immunology and Department of Pathology and Immunology, Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
| | | |
Collapse
|