The molecular machinery for cAMP-dependent immunomodulation in T-cells

2006 ◽  
Vol 34 (4) ◽  
pp. 476-479 ◽  
Author(s):  
K. Taskén ◽  
A.J. Stokka
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Lipid Rafts ◽  
T Cell Activation ◽  
Negative Feedback ◽  
Cell Activation ◽  
Cell Receptor ◽  
Membrane Microdomains ◽  
Type I ◽  
Anchoring Protein

cAMP inhibits Src-family kinase signalling by PKA (protein kinase A)-mediated phosphorylation and activation of Csk (C-terminal Src kinase). The PKA type I–Csk pathway is assembled and localized in membrane microdomains (lipid rafts) and regulates immune responses activated through the TCR (T-cell receptor). PKA type I is targeted to the TCR–CD3 complex during T-cell activation via an AKAP (A-kinase-anchoring protein) that serves as a scaffold for the cAMP–PKA/Csk pathway in lipid rafts of the plasma membrane during T-cell activation. Displacement of PKA by anchoring disruption peptides prevents cAMP/PKA type I-mediated inhibition of T-cell activation. These findings provide functional evidence that PKA type I regulation of T-cell responses is dependent on AKAP anchoring. Furthermore, we show that upon TCR/CD28 co-ligation, β-arrestin in complex with PDE4 (phosphodiesterase 4) is recruited to lipid rafts. The CD28-mediated recruitment of PDE4 to lipid rafts potentiates T-cell immune responses and counteracts the local, TCR-induced production of cAMP that produces negative feedback in the absence of a co-receptor stimulus. The specific recruitment of PDE4 thus serves to abrogate the negative feedback by cAMP which is elicited in the absence of a co-receptor stimulus.

Association of CD26 with CD45RA outside lipid rafts attenuates cord blood T-cell activation

Blood ◽  
2004 ◽  
Vol 103 (3) ◽  
pp. 1002-1010 ◽  
Author(s):  
Seiji Kobayashi ◽  
Kei Ohnuma ◽  
Masahiko Uchiyama ◽  
Kouichi Iino ◽  
Satoshi Iwata ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cord Blood ◽  
Lipid Rafts ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Cell Protein ◽  
Membrane Microdomains

AbstractCD26 is a T-cell activation antigen that contains dipeptidyl peptidase IV activity and binds adenosine deaminase. Recent work showed that specialized membrane microdomains, also known as lipid rafts, play a key role in T-cell signaling. In this study, we investigate the role of CD26 in cord blood T-cell activation and signal transduction. We demonstrated that different expression levels of CD26 were observed between cord blood T cells (CBTCs) and peripheral blood T cells (PBTCs) and that CD26+CD45RA+ CBTCs were different compared with CD26+CD45RA+ PBTCs. Moreover, the comitogenic effect of CD26 was not as pronounced in CBTCs as in PBTCs. We also showed that CD26 cross-linking induced less phosphorylation of T-cell receptor-signaling molecules, lymphoid T-cell protein tyrosine kinase (Lck), zeta-associated protein 70 (ZAP-70), T-cell receptor ζ (TCRζ), and linker for activator of T cells (LAT) in CBTCs than in PBTCs. Furthermore, CD26 molecules associated with CD45RA molecules outside lipid rafts in CBTCs. Our results suggest that strong physical linkage of CD26 with CD45RA outside lipid rafts may be responsible for the attenuation of T-cell activation signaling through CD26, which may be responsible for immature immune response and the low incidence of severe graft-versus-host disease in cord blood transplantation. (Blood. 2004;103:1002-1010)

scholarly journals Inhibition of T Cell Activation by Cyclic Adenosine 5′-Monophosphate Requires Lipid Raft Targeting of Protein Kinase A Type I by the A-Kinase Anchoring Protein Ezrin

2007 ◽  
Vol 179 (8) ◽  
pp. 5159-5168 ◽  
Author(s):  
Anja Ruppelt ◽  
Randi Mosenden ◽  
Mikaela Grönholm ◽  
Einar M. Aandahl ◽  
Derek Tobin ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
T Cell Activation ◽  
Lipid Raft ◽  
Cell Activation ◽  
Type I ◽  
Anchoring Protein ◽  
Kinase A

scholarly journals The coreceptor CD2 uses plasma membrane microdomains to transduce signals in T cells

2009 ◽  
Vol 185 (3) ◽  
pp. 521-534 ◽  
Author(s):  
Yoshihisa Kaizuka ◽  
Adam D. Douglass ◽  
Santosh Vardhana ◽  
Michael L. Dustin ◽  
Ronald D. Vale
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Adaptor Protein ◽  
Cell Receptor ◽  
Signaling Molecules ◽  
Membrane Microdomains ◽  
Receptor Interaction

The interaction between a T cell and an antigen-presenting cell (APC) can trigger a signaling response that leads to T cell activation. Prior studies have shown that ligation of the T cell receptor (TCR) triggers a signaling cascade that proceeds through the coalescence of TCR and various signaling molecules (e.g., the kinase Lck and adaptor protein LAT [linker for T cell activation]) into microdomains on the plasma membrane. In this study, we investigated another ligand–receptor interaction (CD58–CD2) that facilities T cell activation using a model system consisting of Jurkat T cells interacting with a planar lipid bilayer that mimics an APC. We show that the binding of CD58 to CD2, in the absence of TCR activation, also induces signaling through the actin-dependent coalescence of signaling molecules (including TCR-ζ chain, Lck, and LAT) into microdomains. When simultaneously activated, TCR and CD2 initially colocalize in small microdomains but then partition into separate zones; this spatial segregation may enable the two receptors to enhance signaling synergistically. Our results show that two structurally distinct receptors both induce a rapid spatial reorganization of molecules in the plasma membrane, suggesting a model for how local increases in the concentration of signaling molecules can trigger T cell signaling.

Metabolic labelling of membrane microdomains/rafts in Jurkat cells indicates the presence of glycerophospholipids implicated in signal transduction by the CD3 T-cell receptor

2002 ◽  
Vol 363 (3) ◽  
pp. 645-655 ◽  
Author(s):  
Alexandre K. ROUQUETTE-JAZDANIAN ◽  
Claudette PELASSY ◽  
Jean-Philippe BREITTMAYER ◽  
Jean-Louis COUSIN ◽  
Claude AUSSEL
Keyword(s):  
Fatty Acids ◽  
T Cells ◽  
T Cell ◽  
Protein Kinase ◽  
Lipid Rafts ◽  
T Cell Activation ◽  
Cell Activation ◽  
Saturated Fatty Acids ◽  
Membrane Microdomains ◽  
Metabolic Labelling

Cell membranes contain sphingolipids and cholesterol, which cluster together in distinct domains called rafts. The outer-membrane leaflet of these peculiar membrane domains contains glycosylphosphatidylinositol-anchored proteins, while the inner leaflet contains proteins implicated in signalling, such as the acylated protein kinase p56lck and the palmitoylated adaptator LAT (linker for activation of T-cells). We present here an approach to study the lipid composition of rafts and its change upon T-cell activation. Our method is based on metabolic labelling of Jurkat T-cells with different precursors of glycerophospholipid synthesis, including glycerol and fatty acids with different lengths and degrees of saturation as well as phospholipid polar head groups. The results obtained indicate that lipid rafts isolated by the use of sucrose density-gradient centrifugation after Triton X-100 extraction in the cold, besides sphingolipids and cholesterol, contain unambiguously all classes of glycerophospholipids: phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine and phosphatidylcholine. Fatty acid labelling shows that lipid rafts are labelled preferentially with saturated fatty acids while the rest of the plasma membrane incorporates mostly long-chained polyunsaturated fatty acids. To see whether the raft composition as measured by metabolic labelling of phospholipids is involved in T-cell activation, we investigated the production of sn-1,2-diacylglycerol (DAG) in CD3-activated cells. DAG production occurs within rafts, confirming previous demonstration of protein kinase C translocation into membrane microdomains. Our data demonstrate that raft disorganization by methyl-β-cyclodextrin impairs both CD3-induced DAG production and changes in cytosolic Ca2+ concentration. These lines of evidence support the conclusion that the major events in T-cell activation occur within or due to lipid rafts.

scholarly journals General Strategy for Decoration of Enveloped Viruses with Functionally Active Lipid-Modified Cytokines

2007 ◽  
Vol 81 (16) ◽  
pp. 8666-8676 ◽  
Author(s):  
Hans J. Kueng ◽  
Victoria M. Leb ◽  
Daniela Haiderer ◽  
Graça Raposo ◽  
Clotilde Thery ◽  
...  
Keyword(s):  
T Cell ◽  
Lipid Rafts ◽  
T Cell Activation ◽  
Cell Activation ◽  
Specific Activity ◽  
Interleukin 2 ◽  
Cell Types ◽  
General Strategy ◽  
Type I ◽  
Enveloped Viruses

ABSTRACT Viral particles preferentially incorporate extra- and intracellular constituents of host cell lipid rafts, a phenomenon central to pseudotyping. Based on this mechanism, we have developed a system for the predictable decoration of enveloped viruses with functionally active cytokines that circumvents the need to modify viral proteins themselves. Human interleukin-2 (hIL-2), hIL-4, human granulocyte-macrophage colony-stimulating factor (hGM-CSF), and murine IL-2 (mIL-2) were used as model cytokines and fused at their C terminus to the glycosylphosphatidylinositol (GPI) acceptor sequence of human Fcγ receptor III (CD16b). We show here that genetically modified cytokines are all well expressed on 293 producer cells. However, only molecules equipped with GPI anchors but not those linked to transmembrane/intracellular regions of type I membrane proteins are efficiently targeted to lipid rafts and consequently to virus-like particles (VLP) induced by Moloney murine leukemia virus Gag-Pol. hIL-4::GPI and hGM-CSF::GPI coexpressed on VLP were found to differentiate monocytes towards dendritic cells. Apart from myeloid-committed cell types, VLP-bound cytokines also act efficiently on lymphocytes. hIL-2::GPI strongly costimulated T-cell receptor (TCR)/CD3 dependent T-cell activation in vitro and mIL-2::GPI-coactivated antigen-specific T cells in vivo. On a molar basis, the functional activity of VLP-bound hIL-2::GPI was found to be comparable to that of soluble hIL-2. VLP decorated with hIL-2::GPI and coexpressing a TCR/CD3 ligand have an IL-2-specific activity of 5 × 104 units/mg protein. Virus particles decorated with lipid-modified cytokines might help to improve viral strains for vaccination purposes, the propagation of factor-dependent cell types, as well as gene transfer by viral systems in the future.

scholarly journals T-Cell Receptor Microclusters Critical for T-Cell Activation Are Formed Independently of Lipid Raft Clustering

2010 ◽  
Vol 30 (14) ◽  
pp. 3421-3429 ◽  
Author(s):  
Akiko Hashimoto-Tane ◽  
Tadashi Yokosuka ◽  
Chitose Ishihara ◽  
Machie Sakuma ◽  
Wakana Kobayashi ◽  
...  
Keyword(s):  
T Cell ◽  
Lipid Rafts ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Lipid Raft ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Resonance Energy ◽  
Careful Analysis ◽  
Cell Receptor

ABSTRACT We studied the function of lipid rafts in generation and signaling of T-cell receptor microclusters (TCR-MCs) and central supramolecular activation clusters (cSMACs) at immunological synapse (IS). It has been suggested that lipid raft accumulation creates a platform for recruitment of signaling molecules upon T-cell activation. However, several lipid raft probes did not accumulate at TCR-MCs or cSMACs even with costimulation and the fluorescence resonance energy transfer (FRET) between TCR or LAT and lipid raft probes was not induced at TCR-MCs under the condition of positive induction of FRET between CD3ζ and ZAP-70. The analysis of LAT mutants revealed that raft association is essential for the membrane localization but dispensable for TCR-MC formation. Careful analysis of the accumulation of raft probes in the cell interface revealed that their accumulation occurred after cSMAC formation, probably due to membrane ruffling and/or endocytosis. These results suggest that lipid rafts control protein translocation to the membrane but are not involved in the clustering of raft-associated molecules and therefore that the lipid rafts do not serve as a platform for T-cell activation.

scholarly journals Recruitment of Slp-76 to the Membrane and Glycolipid-Enriched Membrane Microdomains Replaces the Requirement for Linker for Activation of T Cells in T Cell Receptor Signaling

2000 ◽  
Vol 192 (7) ◽  
pp. 1047-1058 ◽  
Author(s):  
Nancy J. Boerth ◽  
Jeffrey J. Sadler ◽  
Daniel E. Bauer ◽  
James L. Clements ◽  
Shereen M. Gheith ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Promoter Activity ◽  
Cell Activation ◽  
Cell Receptor ◽  
Membrane Microdomains ◽  
Tcr Signaling

Two hematopoietic-specific adapters, src homology 2 domain–containing leukocyte phosphoprotein of 76 kD (SLP-76) and linker for activation of T cells (LAT), are critical for T cell development and T cell receptor (TCR) signaling. Several studies have suggested that SLP-76 and LAT function coordinately to promote downstream signaling. In support of this hypothesis, we find that a fraction of SLP-76 localizes to glycolipid-enriched membrane microdomains (GEMs) after TCR stimulation. This recruitment of SLP-76 requires amino acids 224–244. The functional consequences of targeting SLP-76 to GEMs for TCR signaling are demonstrated using a LAT/SLP-76 chimeric protein. Expression of this construct reconstitutes TCR-inducted phospholipase Cγ1 phosphorylation, extracellular signal–regulated kinase activation, and nuclear factor of activated T cells (NFAT) promoter activity in LAT-deficient Jurkat T cells (J.CaM2). Mutation of the chimeric construct precluding its recruitment to GEMs diminishes but does not eliminate its ability to support TCR signaling. Expression of a chimera that lacks SLP-76 amino acids 224–244 restores NFAT promoter activity, suggesting that if localized, SLP-76 does not require an association with Gads to promote T cell activation. In contrast, mutation of the protein tyrosine kinase phosphorylation sites of SLP-76 in the context of the LAT/SLP-76 chimera abolishes reconstitution of TCR function. Collectively, these experiments show that optimal TCR signaling relies on the compartmentalization of SLP-76 and that one critical function of LAT is to bring SLP-76 and its associated proteins to the membrane.

scholarly journals Dynamic changes in the mobility of LAT in aggregated lipid rafts upon T cell activation

2003 ◽  
Vol 160 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Natsuko Tanimura ◽  
Masakazu Nagafuku ◽  
Yasuko Minaki ◽  
Yukio Umeda ◽  
Fumie Hayashi ◽  
...  
Keyword(s):  
T Cell ◽  
Lipid Rafts ◽  
T Cell Activation ◽  
Binding Sites ◽  
Cell Activation ◽  
Cell Receptor ◽  
Live Cells ◽  
Receptor Stimulation ◽  
Dynamic Changes ◽  
Phospholipase Cγ1

Lipid rafts are known to aggregate in response to various stimuli. By way of raft aggregation after stimulation, signaling molecules in rafts accumulate and interact so that the signal received at a given membrane receptor is amplified efficiently from the site of aggregation. To elucidate the process of lipid raft aggregation during T cell activation, we analyzed the dynamic changes of a raft-associated protein, linker for activation of T cells (LAT), on T cell receptor stimulation using LAT fused to GFP (LAT-GFP). When transfectants expressing LAT-GFP were stimulated with anti-CD3–coated beads, LAT-GFP aggregated and formed patches at the area of bead contact. Photobleaching experiments using live cells revealed that LAT-GFP in patches was markedly less mobile than that in nonpatched regions. The decreased mobility in patches was dependent on raft organization supported by membrane cholesterol and signaling molecule binding sites, especially the phospholipase Cγ1 binding site in the cytoplasmic domain of LAT. Thus, although LAT normally moves rapidly at the plasma membrane, it loses its mobility and becomes stably associated with aggregated rafts to ensure organized and sustained signal transduction required for T cell activation.

scholarly journals USP18 inhibits NF-κB and NFAT activation during Th17 differentiation by deubiquitinating the TAK1–TAB1 complex

2013 ◽  
Vol 210 (8) ◽  
pp. 1575-1590 ◽  
Author(s):  
Xikui Liu ◽  
Hongxiu Li ◽  
Bo Zhong ◽  
Marzenna Blonska ◽  
Sara Gorjestani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Type I ◽  
T Helper 17 ◽  
Th17 Cell Differentiation ◽  
Nfat Activation ◽  
Th17 Differentiation

Reversible ubiquitin modification of cell signaling molecules has emerged as a critical mechanism by which cells respond to extracellular stimuli. Although ubiquitination of TGF-β–activated kinase 1 (TAK1) is critical for NF-κB activation in T cells, the regulation of its deubiquitination is unclear. We show that USP18, which was previously reported to be important in regulating type I interferon signaling in innate immunity, regulates T cell activation and T helper 17 (Th17) cell differentiation by deubiquitinating the TAK1–TAB1 complex. USP18-deficient T cells are defective in Th17 differentiation and Usp18−/− mice are resistant to experimental autoimmune encephalomyelitis (EAE). In response to T cell receptor engagement, USP18-deficient T cells exhibit hyperactivation of NF-κB and NFAT and produce increased levels of IL-2 compared with the wild-type controls. Importantly, USP18 is associated with and deubiquitinates the TAK1–TAB1 complex, thereby restricting expression of IL-2. Our findings thus demonstrate a previously uncharacterized negative regulation of TAK1 activity during Th17 differentiation, suggesting that USP18 may be targeted to treat autoimmune diseases.

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