Engagement of specific T-cell surface molecules regulates cytoskeletal polarization in HTLV-1–infected lymphocytes

Blood ◽  
2005 ◽  
Vol 106 (3) ◽  
pp. 988-995 ◽  
Author(s):  
Amanda L. Barnard ◽  
Tadahiko Igakura ◽  
Yuetsu Tanaka ◽  
Graham P. Taylor ◽  
Charles R.M. Bangham
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
Contact Region ◽  
Intercellular Adhesion Molecule ◽  
Cell Junction ◽  
Cell Contact ◽  
Intercellular Adhesion Molecule 1 ◽  
Microtubule Organizing Center ◽  
Infected Cells ◽  
Cell Cell

Abstract Cell-cell contact is required for efficient transmission of human T-lymphotropic virus type 1 (HTLV-1). An HTLV-1–infected cell polarizes its microtubule-organizing center (MTOC) toward the cell-cell junction; HTLV-1 core (Gag) complexes and the HTLV-1 genome accumulate at the point of contact and are then transferred to the uninfected cell. However, the mechanisms involved in this cytoskeletal polarization and transport of HTLV-1 complexes are unknown. Here, we tested the hypothesis that engagement of a specific T-cell surface ligand is synergistic with HTLV-1 infection in causing polarization of the MTOC to the cell contact region. We show that antibodies to intercellular adhesion molecule-1 (ICAM-1; CD54) caused MTOC polarization at a higher frequency in HTLV-1–infected cells. ICAM-1 is upregulated on HTLV-1–infected cells, and, in turn, ICAM-1 on the cell surface upregulates HTLV-1 gene expression. We propose that a positive feedback loop involving ICAM-1 and HTLV-1 Tax protein facilitates the formation of the virologic synapse and contributes to the T-cell tropism of HTLV-1. In contrast, MTOC polarization induced in T cells by antibodies to CD3 or CD28 was significantly inhibited by HTLV-1 infection.

HTLV-1–Tax and ICAM-1 act on T-cell signal pathways to polarize the microtubule-organizing center at the virological synapse

Blood ◽  
2009 ◽  
Vol 114 (5) ◽  
pp. 1016-1025 ◽  
Author(s):  
Mohamed Nejmeddine ◽  
Veera S. Negi ◽  
Sohini Mukherjee ◽  
Yuetsu Tanaka ◽  
Kim Orth ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Contact Region ◽  
Intercellular Adhesion Molecule ◽  
Virological Synapse ◽  
Cell Contact ◽  
Signal Pathways ◽  
Microtubule Organizing Center ◽  
Organizing Center ◽  
Stimulation Of

Human T-lymphotropic virus type 1 (HTLV-1) spreads directly between lymphocytes and other cells via a specialized cell-cell contact, termed the virological synapse. The formation of the virological synapse is accompanied by the orientation of the microtubule-organizing center (MTOC) in the infected T cell toward the cell contact region with the noninfected target cell. We previously demonstrated that the combination of intracellular Tax protein expression and the stimulation of the intercellular adhesion molecule-1 (ICAM-1) on the cell surface is sufficient to trigger MTOC polarization in the HTLV-1–infected T cell. However, the mechanism by which Tax and ICAM-1 cause the MTOC polarization is not fully understood. Here we show that the presence of Tax at the MTOC region and its ability to stimulate cyclic AMP-binding protein–dependent pathways are both required for MTOC polarization in the HTLV-1–infected T cell at the virological synapse. Furthermore, we show that the MTOC polarization induced by ICAM-1 engagement depends on activation of the Ras-MEK-ERK signaling pathway. Our findings indicate that efficient MTOC polarization at the virological synapse requires Tax-mediated stimulation of T-cell activation pathways in synergy with ICAM-1 cross-linking. The results also reveal differences in the signaling pathways used to trigger MTOC polarization between the immunologic synapse and the virological synapse.

scholarly journals Actin and agonist MHC–peptide complex–dependent T cell receptor microclusters as scaffolds for signaling

2005 ◽  
Vol 202 (8) ◽  
pp. 1031-1036 ◽  
Author(s):  
Gabriele Campi ◽  
Rajat Varma ◽  
Michael L. Dustin
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Actin Polymerization ◽  
Kinase Inhibitor ◽  
Cell Receptor ◽  
Intercellular Adhesion Molecule ◽  
Cell Contact ◽  
Intercellular Adhesion Molecule 1 ◽  
Planar Bilayers ◽  
Latrunculin A

T cell receptor (TCR) microclusters form within seconds of T cell contact with supported planar bilayers containing intercellular adhesion molecule-1 and agonist major histocompatibility complex (MHC)–peptide complexes, and elevation of cytoplasmic Ca2+ is observed within seconds of the first detectable microclusters. At 0–30 s after contact, TCR microclusters are colocalized with activated forms of Lck, ZAP-70, and the linker for activation of T cells. By 2 min, activated kinases are reduced in the older central microclusters, but are abundant in younger peripheral microclusters. By 5 min, TCR in the central supramolecular activation cluster have reduced activated kinases, whereas faint peripheral TCR microclusters efficiently generated activated Lck and ZAP-70. TCR microcluster formation is resistant to inhibition by Src family kinase inhibitor PP2, but is abrogated by actin polymerization inhibitor latrunculin A. We propose that Src kinase–independent formation of TCR microclusters in response to agonist MHC–peptide provides an actin-dependent scaffold for signal amplification.

scholarly journals Patterns for RANTES Secretion and Intercellular Adhesion Molecule 1 Expression Mediate Transepithelial T Cell Traffic Based on Analyses In Vitro and In Vivo

1998 ◽  
Vol 187 (12) ◽  
pp. 1927-1940 ◽  
Author(s):  
Masahiko Taguchi ◽  
Deepak Sampath ◽  
Takeharu Koga ◽  
Mario Castro ◽  
Dwight C. Look ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
Cell Surface ◽  
Immune Cell ◽  
Intercellular Adhesion Molecule ◽  
Airway Epithelial ◽  
Intercellular Adhesion Molecule 1 ◽  
Ifn Γ

Immune cell migration into and through mucosal barrier sites in general and airway sites in particular is a critical feature of immune and inflammatory responses, but the determinants of transepithelial (unlike transendothelial) immune cell traffic are poorly defined. Accordingly, we used primary culture airway epithelial cells and peripheral blood mononuclear cells to develop a cell monolayer system that allows for apical-to-basal and basal-to-apical T cell transmigration that can be monitored with quantitative immunofluorescence flow cytometry. In this system, T cell adhesion and subsequent transmigration were blocked in both directions by monoclonal antibodies (mAbs) against lymphocyte function-associated antigen 1 (LFA-1) or intercellular adhesion molecule 1 (ICAM-1) (induced by interferon γ [IFN-γ] treatment of epithelial cells). The total number of adherent plus transmigrated T cells was also similar in both directions, and this pattern fit with uniform presentation of ICAM-1 along the apical and basolateral cell surfaces. However, the relative number of transmigrated to adherent T cells (i.e., the efficiency of transmigration) was increased in the basal-to-apical relative to the apical-to-basal direction, so an additional mechanism was needed to mediate directional movement towards the apical surface. Screening for epithelial-derived β-chemokines indicated that IFN-γ treatment caused selective expression of RANTES (regulated upon activation, normal T cell expressed and secreted), and the functional significance of this finding was demonstrated by inhibition of epithelial–T cell adhesion and transepithelial migration by anti-RANTES mAbs. In addition, we found that epithelial (but not endothelial) cells preferentially secreted RANTES through the apical cell surface thereby establishing a chemical gradient for chemotaxis across the epithelium to a site where they may be retained by high levels of RANTES and apical ICAM-1. These patterns for epithelial presentation of ICAM-1 and secretion of RANTES appear preserved in airway epithelial tissue studied either ex vivo with expression induced by IFN-γ treatment or in vivo with endogenous expression induced by inflammatory disease (i.e., asthma). Taken together, the results define how the patterns for uniform presentation of ICAM-1 along the cell surface and specific apical sorting of RANTES may serve to mediate the level and directionality of T cell traffic through epithelium (distinct from endothelium) and provide a basis for how this process is precisely coordinated to route immune cells to the mucosal surface and maintain them there under normal and stimulated conditions.

scholarly journals Interplay Between SNX27 and DAG Metabolism in the Control of Trafficking and Signaling at the IS

2020 ◽  
Vol 21 (12) ◽  
pp. 4254
Author(s):  
Natalia González-Mancha ◽  
Isabel Mérida
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Communication ◽  
Negative Regulator ◽  
Cell Junction ◽  
Microtubule Organizing Center ◽  
Immune Synapse ◽  
Organizing Center ◽  
Cell Cell

Recognition of antigens displayed on the surface of an antigen-presenting cell (APC) by T-cell receptors (TCR) of a T lymphocyte leads to the formation of a specialized contact between both cells named the immune synapse (IS). This highly organized structure ensures cell–cell communication and sustained T-cell activation. An essential lipid regulating T-cell activation is diacylglycerol (DAG), which accumulates at the cell–cell interface and mediates recruitment and activation of proteins involved in signaling and polarization. Formation of the IS requires rearrangement of the cytoskeleton, translocation of the microtubule-organizing center (MTOC) and vesicular compartments, and reorganization of signaling and adhesion molecules within the cell–cell junction. Among the multiple players involved in this polarized intracellular trafficking, we find sorting nexin 27 (SNX27). This protein translocates to the T cell–APC interface upon TCR activation, and it is suggested to facilitate the transport of cargoes toward this structure. Furthermore, its interaction with diacylglycerol kinase ζ (DGKζ), a negative regulator of DAG, sustains the precise modulation of this lipid and, thus, facilitates IS organization and signaling. Here, we review the role of SNX27, DAG metabolism, and their interplay in the control of T-cell activation and establishment of the IS.

Use of conjugates made between a cytolytic T cell clone and target cells to study the redistribution of membrane molecules in cell contact areas

1990 ◽  
Vol 97 (2) ◽  
pp. 335-347
Author(s):  
P. Andre ◽  
A.M. Benoliel ◽  
C. Capo ◽  
C. Foa ◽  
M. Buferne ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
Cell Interaction ◽  
Cell Contact ◽  
Computer Assisted ◽  
Target Cells ◽  
Contact Areas ◽  
Surface Molecules ◽  
T Cell Clone ◽  
Cell Cell

In many models of cell-cell adhesion, it was reported that some cell membrane molecules might be redistributed into contact areas. However, this phenomenon was not subjected to precise quantification. In the present work, fluorescence microscopy, immunolabelling and digital image processing were combined to analyse quantitatively the spatial organization of specific or nonspecific conjugates made with a cytolytic T (CTL) lymphocyte clone (BM3.3) and target cells (EL4 or RDM4). Binding was achieved under calcium-free conditions to study the earliest steps of cell interaction, preceding CTL activation. Fluorescent antibodies were used to label class I histocompatibility molecules on both killer and target cells, and T cell receptor, CD3, CD8 and LFA-1 (CD18/CD11a) on the killer cells. Membrane bilayers were stained with a fluorescent phospholipid, glycoconjugates were labelled with periodic oxidation and Lucifer Yellow uptake, and polymerized actin was revealed with a fluorescent phallacidin derivative. Also, the fine geometry of killer-target interaction area was studied with electron microscopy and computer-assisted contour analysis. It is concluded that: (1) qualitative examination of fluorescence photomicrographs cannot permit accurate comparison between different fluorescence densities. (2) The cell-cell contact area was about fourfold higher in specific conjugates than in non-specific ones. (3) The surface density of adhesion molecules exhibited similar increases (between 30 and 80%) in the contact areas of both specific and nonspecific conjugates. (4) However, the amount of redistributed surface molecules was higher when cell-cell interaction was enhanced either by specific immunological recognition (in specific conjugates) or periodate oxidation. (5) Since redistribution did not require extracellular calcium and it was detected on nonspecific conjugates, this did not require full lymphocyte activation. Spatial reorganization of cell surface molecules may thus be a general consequence of adhesion, cell surface mobility and intermolecular forces.

scholarly journals LFA-1 Engagement Triggers T Cell Polarization at the HIV-1 Virological Synapse

2016 ◽  
Vol 90 (21) ◽  
pp. 9841-9854 ◽  
Author(s):  
Shimona Starling ◽  
Clare Jolly
Keyword(s):  
T Cell ◽  
Cell Polarization ◽  
Cell Contact ◽  
Cell Remodeling ◽  
T Cell Polarization ◽  
Infected Cells ◽  
Virological Synapses ◽  
Cell Spread ◽  
Hiv 1 ◽  
Cell Cell

ABSTRACTHIV-1 efficiently disseminates by cell-cell spread at intercellular contacts called virological synapses (VS), where the virus preferentially assembles and buds. Cell-cell contact triggers active polarization of organelles and viral proteins within infected cells to the contact site to support efficient VS formation and HIV-1 spread; critically, however, which cell surface protein triggers contact-induced polarization at the VS remains unclear. Additionally, the mechanism by which the HIV-1 envelope glycoprotein (Env) is recruited to the VS remains ill defined. Here, we use a reductionist bead-coupled antibody assay as a model of the VS and show that cross-linking the integrin LFA-1 alone is sufficient to induce active T cell polarization and recruitment of the microtubule organizing center (MTOC) in HIV-1-infected cells. Mutant cell lines coupled with inhibitors demonstrated that LFA-1-induced polarization was dependent on the T cell kinase ZAP70. Notably, immunofluorescent staining of viral proteins revealed an accumulation of surface Env at sites of LFA-1 engagement, with intracellular Env localized to a Golgi compartment proximal to the polarized MTOC. Furthermore, blocking LFA-1-induced MTOC polarization through ZAP70 inhibition prevented intracellular Env polarization. Taken together, these data reveal that LFA-1 is a key determinant in inducing dynamic T cell remodeling to the VS and suggest a model in which LFA-1 engagement triggers active polarization of the MTOC and the associated Env-containing secretory apparatus to sites of cell-cell contact to support polarized viral assembly and egress for efficient cell-cell spread.IMPORTANCEHIV-1 causes AIDS by spreading within immune cells and depletion of CD4 T lymphocytes. Rapid spread between these cells occurs by highly efficient cell-cell transmission that takes place at virological synapses (VS). VS are characterized by striking T cell remodeling that is spatially associated with polarized virus assembly and budding at sites of cell contact. Here, we show that the integrin LFA-1 triggers organelle polarization and viral protein recruitment, facilitating formation of the VS, and that this requires the T cell kinase ZAP70. Taken together, these data suggest a mechanism by which HIV-1-infected T cells sense and respond to cell contact to polarize viral egress and promote cell-cell spread. Understanding how cell-cell spread is regulated may help reveal therapeutic targets to specifically block this mode of HIV-1 dissemination.

sPAR-3, a splicing variant of PAR-3, shows cellular localization and an expression pattern different from that of PAR-3 during enterocyte polarization

2005 ◽  
Vol 288 (3) ◽  
pp. G564-G570 ◽  
Author(s):  
Takako Yoshii ◽  
Keiko Mizuno ◽  
Tomonori Hirose ◽  
Atsushi Nakajima ◽  
Hisahiko Sekihara ◽  
...  
Keyword(s):  
Tight Junctions ◽  
Cellular Localization ◽  
Biochemical Characterization ◽  
Contact Region ◽  
Cell Junctions ◽  
Cell Junction ◽  
Cell Contact ◽  
Atypical Pkc ◽  
Polarized Cells ◽  
Cell Cell

PAR-3 (partitioning-defective) is a scaffold-like PDZ (postsynaptic density-95/discs large/zonula occludens-1) domain-containing protein that forms a complex with PAR-6 and atypical PKC, localizes to tight junctions, and contributes to the formation of functional tight junctions. There are several alternatively spliced isoforms of PAR-3, although their physiological significance remains unknown. In this study, we show that one of the major isoforms of PAR-3, sPAR-3, is predominantly expressed in the Caco-2 cells derived from colon carcinoma and is used as a model to investigate the events involved in the epithelial cell differentiation and cell polarity development. During the polarization of Caco-2 cells, the expression of PAR-3 increases as do those of other cell-cell junction proteins, whereas the expression of sPAR-3 decreases. Biochemical characterization revealed that sPAR-3 associates with atypical PKC, as does PAR-3. On the other hand, immunofluorescence microscopy revealed that sPAR-3 does not concentrate at the cell-cell contact region in fully polarized cells, whereas it concentrates at premature cell-cell junctions. This makes a contrast to PAR-3, which concentrates at tight junctions in fully polarized cells. These results provide evidence suggesting the difference in the role between sPAR-3 and PAR-3 in epithelial cells.

Sign in / Sign up

Export Citation Format

Share Document