201
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Chen HY, Fermin A, Vardhana S, Weng IC, Lo KFR, Chang EY, Maverakis E, Yang RY, Hsu DK, Dustin ML, Liu FT. Galectin-3 negatively regulates TCR-mediated CD4+ T-cell activation at the immunological synapse. Proc Natl Acad Sci U S A 2009; 106:14496-501. [PMID: 19706535 PMCID: PMC2732795 DOI: 10.1073/pnas.0903497106] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Indexed: 12/16/2022] Open
Abstract
We have investigated the function of endogenous galectin-3 in T cells. Galectin-3-deficient (gal3(-/-)) CD4(+) T cells secreted more IFN-gamma and IL-4 than gal3(+/+)CD4(+) T cells after T-cell receptor (TCR) engagement. Galectin-3 was recruited to the cytoplasmic side of the immunological synapse (IS) in activated T cells. In T cells stimulated on supported lipid bilayers, galectin-3 was primarily located at the peripheral supramolecular activation cluster (pSMAC). Gal3(+/+) T cells formed central SMAC on lipid bilayers less effectively and adhered to antigen-presenting cells less firmly than gal3(-/-) T cells, suggesting that galectin-3 destabilizes the IS. Galectin-3 expression was associated with lower levels of early signaling events and phosphotyrosine signals at the pSMAC. Additional data suggest that galectin-3 potentiates down-regulation of TCR in T cells. By yeast two-hybrid screening, we identified as a galectin-3-binding partner, Alix, which is known to be involved in protein transport and regulation of cell surface expression of certain receptors. Co-immunoprecipitation confirmed galectin-3-Alix association and immunofluorescence analysis demonstrated the translocation of Alix to the IS in activated T cells. We conclude that galectin-3 is an inhibitory regulator of T-cell activation and functions intracellularly by promoting TCR down-regulation, possibly through modulating Alix's function at the IS.
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Affiliation(s)
- Huan-Yuan Chen
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - Agnes Fermin
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - Santosh Vardhana
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016
| | - I-Chun Weng
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - Kin Fong Robin Lo
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - En-Yuh Chang
- La Jolla Institute for Allergy and Immunology, San Diego, CA 92037; and
| | - Emanual Maverakis
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
- Veterans Affairs Northern California Health Care System, Sacramento, CA 95655
| | - Ri-Yao Yang
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - Daniel K Hsu
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
| | - Michael L. Dustin
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016
| | - Fu-Tong Liu
- Department of Dermatology, School of Medicine, University of California at Davis, Sacramento, CA 95817
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202
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Hartman NC, Nye JA, Groves JT. Cluster size regulates protein sorting in the immunological synapse. Proc Natl Acad Sci U S A 2009; 106:12729-34. [PMID: 19622735 PMCID: PMC2722343 DOI: 10.1073/pnas.0902621106] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Indexed: 11/18/2022] Open
Abstract
During antigen recognition by T cells, signaling molecules on the T cell engage ligands on the antigen-presenting cell and organize into spatially distinctive patterns. These are collectively known as the immunological synapse (IS). Causal relationships between large-scale spatial organization and signal transduction have previously been established. Although it is known that receptor transport during IS formation is driven by actin polymerization, the mechanisms by which different proteins become spatially sorted remain unclear. These sorting processes contribute a facet of signal regulation; thus their elucidation is important for ultimately understanding signal transduction through the T cell receptor. Here we investigate protein cluster size as a sorting mechanism using the hybrid live T cell-supported membrane system. The clustering state of the co-stimulatory molecule lymphocyte function-associated antigen-1 (LFA-1) is modulated, either by direct antibody crosslinking or by crosslinking its intercellular adhesion molecule-1 ligand on the supported bilayer. In a mature IS, native LFA-1 generally localizes into a peripheral ring surrounding a central T cell receptor cluster. Higher degrees of LFA-1 clustering, induced by either method, result in progressively more central localization, with the most clustered species fully relocated to the central zone. These results demonstrate that cluster size directly influences protein spatial positioning in the T cell IS. We discuss a sorting mechanism, based on frictional coupling to the actin cytoskeleton, that is consistent with these observations and is, in principle, extendable to all cell surface proteins in the synapse.
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Affiliation(s)
| | | | - Jay T. Groves
- Departments of Chemistry and
- Howard Hughes Medical Institute, and
- Physical Biosciences and Materials Sciences Divisions, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720
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203
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Davis DM. Mechanisms and functions for the duration of intercellular contacts made by lymphocytes. Nat Rev Immunol 2009; 9:543-55. [PMID: 19609264 DOI: 10.1038/nri2602] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Communication across intercellular contacts is central to establishing appropriate innate and adaptive immune responses. Recent imaging of lymphocyte interactions suggests that a complex orchestration of cell-cell contact times is a key correlate to establishing appropriate immune responses. Here I review the molecular and cellular processes that influence the duration of intercellular contacts, including integrin activation and dynamic changes in membrane morphology. I discuss how these processes can be regulated, for example, by the balance of activating and inhibitory receptor signals, and how they can establish the appropriate outcome for individual cell-cell interactions.
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Affiliation(s)
- Daniel M Davis
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, South Kensington, London, SW7 2AZ, UK.
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204
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Bouma G, Burns SO, Thrasher AJ. Wiskott-Aldrich Syndrome: Immunodeficiency resulting from defective cell migration and impaired immunostimulatory activation. Immunobiology 2009; 214:778-90. [PMID: 19628299 PMCID: PMC2738782 DOI: 10.1016/j.imbio.2009.06.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Regulation of the actin cytoskeleton is crucial for many aspects of correct and cooperative functioning of immune cells, such as migration, antigen uptake and cell activation. The Wiskott-Aldrich Syndrome protein (WASp) is an important regulator of actin cytoskeletal rearrangements and lack of this protein results in impaired immune function. This review discusses recent new insights of the role of WASp at molecular and cellular level and evaluates how WASp deficiency affects important immunological features and how defective immune cell function contributes to compromised host defence.
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Affiliation(s)
- Gerben Bouma
- Centre for Immunodeficiency, UCL Institute of Child Health, London, UK.
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205
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Yokosuka T, Saito T. Dynamic regulation of T-cell costimulation through TCR-CD28 microclusters. Immunol Rev 2009; 229:27-40. [PMID: 19426213 DOI: 10.1111/j.1600-065x.2009.00779.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SUMMARY T-cell activation requires contact between T cells and antigen-presenting cells (APCs) to bring T-cell receptors (TCRs) and major histocompatibility complex peptide (MHCp) together to the same complex. These complexes rearrange to form a concentric circular structure, the immunological synapse (IS). After the discovery of the IS, dynamic imaging technologies have revealed the details of the IS and provided important insights for T-cell activation. We have redefined a minimal unit of T-cell activation, the 'TCR microcluster', which recognizes MHCp, triggers an assembly of assorted molecules downstream of the TCR, and induces effective signaling from TCRs. The relationship between TCR signaling and costimulatory signaling was analyzed in terms of the TCR microcluster. CD28, the most valuable costimulatory receptor, forms TCR-CD28 microclusters in cooperation with TCRs, associates with protein kinase C theta, and effectively induces initial T-cell activation. After mature IS formation, CD28 microclusters accumulate at a particular subregion of the IS, where they continuously assemble with the kinases and not TCRs, and generate sustained T-cell signaling. We propose here a 'TCR-CD28 microcluster' model in which TCR and costimulatory microclusters are spatiotemporally formed at the IS and exhibit fine-tuning of T-cell responses by assembling with specific players downstream of the TCR and CD28.
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Affiliation(s)
- Tadashi Yokosuka
- Laboratory for Cell Signaling, RIKEN Research Center for Allergy, Immunology, Yokohama, Japan
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206
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Immunological synapse formation inhibits, via NF-kappaB and FOXO1, the apoptosis of dendritic cells. Nat Immunol 2009; 10:753-60. [PMID: 19503105 DOI: 10.1038/ni.1750] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Accepted: 05/12/2009] [Indexed: 12/30/2022]
Abstract
The immunological synapse (IS) is a cell-cell junction formed between CD4(+) T cells and dendritic cells (DCs). Here we show in vitro and in vivo that IS formation inhibits apoptosis of DCs. Consistent with these results, IS formation induced antiapoptotic signaling events, including activation of the kinase Akt1 and localization of the prosurvival transcription factor NF-kappaB and the proapoptotic transcription factor FOXO1 to the nucleus and cytoplasm, respectively. Inhibition of phosphatidylinositol 3-OH kinase and Akt1 partially prevented the antiapoptotic effects of IS formation. Direct stimulation of the IS component CD40 on DCs leads to the activation of Akt1, suggesting the involvement of this receptor in the antiapoptotic effects observed upon IS formation.
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207
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Yuseff MI, Lankar D, Lennon-Duménil AM. Dynamics of membrane trafficking downstream of B and T cell receptor engagement: impact on immune synapses. Traffic 2009; 10:629-36. [PMID: 19416472 PMCID: PMC2723867 DOI: 10.1111/j.1600-0854.2009.00913.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Accepted: 03/12/2009] [Indexed: 12/01/2022]
Abstract
The onset of an adaptive immune response requires the activation of T and B lymphocytes by antigen-presenting cells, through a specialized form of intercellular communication, known as the immunological synapse (IS). In B lymphocytes the IS promotes efficient recognition and acquisition of membrane-bound Ags, while in T cells, it modulates the T cell response upon exposure to peptide-major histocompatibility complexes. In this review, we highlight the similarities that determine B and T cell activation, focusing on immune receptor downstream signaling events that lead to synapse formation. We stress the notion that polarization of T and B lymphocytes characterized by global changes in cytoskeleton and membrane trafficking modulates synapse structure and function, thus determining lymphocyte effector functions and fate.
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Affiliation(s)
| | - Danielle Lankar
- INSERM U932, Institut Curie12 rue Lhomond, 75005, Paris, France
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208
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Praveen K, Zheng Y, Rivas F, Gajewski TF. Protein kinase Ctheta focusing at the cSMAC is a consequence rather than cause of TCR signaling and is dependent on the MEK/ERK pathway. THE JOURNAL OF IMMUNOLOGY 2009; 182:6022-30. [PMID: 19414753 DOI: 10.4049/jimmunol.0800897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Correlation between protein kinase Ctheta focusing within the central supramolecular activation cluster (cSMAC) of the immunological synapse and optimal TCR/costimulatory receptor ligation was interpreted to imply that PKCtheta focusing is required for productive signaling. However, this notion has been called into question and competing data suggest that the cSMAC contributes to receptor down-modulation. The observation that PKCtheta focusing at the cSMAC is promoted by CD28 coligation, and also that it occurs late after proximal tyrosine phosphorylation events have been initiated, has led us to investigate an alternative possibility that PKCtheta focusing might be a consequence rather than a cause of productive integrated signaling. Indeed, we found that inhibition of the downstream signaling molecules MEK and PI3K (but not of calcineurin, NF-kappaB, JNK, or p38 MAPK) significantly prevented the focusing of PKCtheta at the cSMAC. It recently has been suggested that the cSMAC may be associated with TCR degradation and signal termination. Using MEK inhibition as a tool, we observed that absence of detectable PKCtheta focusing had no significant effect on TCR down-modulation or duration of CD3zeta phosphorylation. Our results suggest that PKCtheta focusing at the cSMAC occurs as a consequence of productive integrated downstream signaling at least at the level of MEK. If PKCtheta focusing accurately reflects the cSMAC as a whole, then our data also argue against the cSMAC as being required for proximal TCR signal termination.
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Affiliation(s)
- Kesavannair Praveen
- Department of Pathology, Committees on Immunology and Cancer Biology, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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209
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Kaizuka Y, Douglass AD, Vardhana S, Dustin ML, Vale RD. The coreceptor CD2 uses plasma membrane microdomains to transduce signals in T cells. J Cell Biol 2009; 185:521-34. [PMID: 19398758 PMCID: PMC2700390 DOI: 10.1083/jcb.200809136] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 04/08/2009] [Indexed: 01/09/2023] Open
Abstract
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-zeta 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.
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Affiliation(s)
- Yoshihisa Kaizuka
- The Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143
| | - Adam D. Douglass
- The Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143
| | - Santosh Vardhana
- Program in Molecular Pathogenesis, Helen and Martin Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Pathology, New York University School of Medicine, New York, NY 10016
| | - Michael L. Dustin
- Program in Molecular Pathogenesis, Helen and Martin Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Pathology, New York University School of Medicine, New York, NY 10016
| | - Ronald D. Vale
- The Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143
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210
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Bour-Jordan H, Bluestone JA. Regulating the regulators: costimulatory signals control the homeostasis and function of regulatory T cells. Immunol Rev 2009; 229:41-66. [PMID: 19426214 PMCID: PMC2714548 DOI: 10.1111/j.1600-065x.2009.00775.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SUMMARY Costimulation is a concept that goes back to the early 1980s when Lafferty and others hypothesized that cell surface and soluble molecules must exist that are essential for initiating immune responses subsequent to antigen exposure. The explosion in this field of research ensued as over a dozen molecules have been identified to function as second signals following T-cell receptor engagement. By 1994, it seemed clear that the most prominent costimulatory pathway CD28 and functionally related costimulatory molecules, such as CD154, were the major drivers of a positive immune response. Then the immunology world turned upside down. CD28 knockout mice, which were, in most cases, immunodeficient, led to increased autoimmunity when bred into the non-obese diabetic background. Another CD28 family member, cytotoxic T-lymphocyte-associated protein 4, which was presumed to be a costimulatory molecule on activated T cells, turned out to be critical in downregulating immunity. These results, coupled with the vast suppressor cell literature which had been largely rebuked, suggested that the immune system was not poised for response but controlled in such a way that regulation was dominant. Over the last decade, we have learned that these costimulatory molecules play a key role in the now classical CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) that provide critical control of unwanted autoimmune responses. In this review, we discuss the connections between costimulation and Tregs that have changed the costimulation paradigm.
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Affiliation(s)
- Hélène Bour-Jordan
- UCSF Diabetes Center, University of California at San Francisco, San Francisco, CA USA
| | - Jeffrey A. Bluestone
- UCSF Diabetes Center, University of California at San Francisco, San Francisco, CA USA
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211
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Ilani T, Vasiliver-Shamis G, Vardhana S, Bretscher A, Dustin ML. T cell antigen receptor signaling and immunological synapse stability require myosin IIA. Nat Immunol 2009; 10:531-9. [PMID: 19349987 PMCID: PMC2719775 DOI: 10.1038/ni.1723] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Accepted: 03/05/2009] [Indexed: 11/09/2022]
Abstract
Immunological synapses are initiated by signaling in discrete T cell antigen receptor microclusters and are important for the differentiation and effector functions of T cells. Synapse formation involves the orchestrated movement of microclusters toward the center of the contact area with the antigen-presenting cell. Microcluster movement is associated with centripetal actin flow, but the function of motor proteins is unknown. Here we show that myosin IIA was necessary for complete assembly and movement of T cell antigen receptor microclusters. In the absence of myosin IIA or its ATPase activity, T cell signaling was interrupted 'downstream' of the kinase Lck and the synapse was destabilized. Thus, T cell antigen receptor signaling and the subsequent formation of immunological synapses are active processes dependent on myosin IIA.
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Affiliation(s)
- Tal Ilani
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
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212
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Kiesel JR, Buchwald ZS, Aurora R. Cross-Presentation by Osteoclasts Induces FoxP3 in CD8+T Cells. THE JOURNAL OF IMMUNOLOGY 2009; 182:5477-87. [DOI: 10.4049/jimmunol.0803897] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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213
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Abstract
Classical alphabeta T cells protect the host by monitoring intracellular and extracellular proteins in a two-step process. The first step is protein degradation and combination with a major histocompatibility complex (MHC) molecule, leading to surface expression of this amalgam (antigen processing). The second step is the interaction of the T cell receptor with the MHC-peptide complex, leading to signaling in the T cells (antigen recognition). The context for this interaction is a T cell-antigen presenting cell junction, known as an immunological synapse if symmetric and stable and as a kinapse if asymmetric and mobile. The physiological recognition of a ligand takes place most efficiently in the F-actin-rich lamellipodium and is F-actin dependent in stages of formation and triggering and myosin II dependent for signal amplification. This review discusses how these concepts emerged from early studies on adhesion, signaling, and cell biology of T cells.
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Affiliation(s)
- Michael L Dustin
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
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214
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Stone JD, Chervin AS, Kranz DM. T-cell receptor binding affinities and kinetics: impact on T-cell activity and specificity. Immunology 2009; 126:165-76. [PMID: 19125887 DOI: 10.1111/j.1365-2567.2008.03015.x] [Citation(s) in RCA: 279] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The interaction between the T-cell receptor (TCR) and its peptide-major histocompatibility complex (pepMHC) ligand plays a critical role in determining the activity and specificity of the T cell. The binding properties associated with these interactions have now been studied in many systems, providing a framework for a mechanistic understanding of the initial events that govern T-cell function. There have been various other reviews that have described the structural and biochemical features of TCR : pepMHC interactions. Here we provide an overview of four areas that directly impact our understanding of T-cell function, as viewed from the perspective of the TCR : pepMHC interaction: (1) relationships between T-cell activity and TCR : pepMHC binding parameters, (2) TCR affinity, avidity and clustering, (3) influence of coreceptors on pepMHC binding by TCRs and T-cell activity, and (4) impact of TCR binding affinity on antigenic peptide specificity.
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Affiliation(s)
- Jennifer D Stone
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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215
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Singleton KL, Roybal KT, Sun Y, Fu G, Gascoigne NRJ, van Oers NSC, Wülfing C. Spatiotemporal patterning during T cell activation is highly diverse. Sci Signal 2009; 2:ra15. [PMID: 19351954 PMCID: PMC2694444 DOI: 10.1126/scisignal.2000199] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Temporal and spatial variations in the concentrations of signaling intermediates in a living cell are important for signaling in complex networks because they modulate the probabilities that signaling intermediates will interact with each other. We have studied 30 signaling sensors, ranging from receptors to transcription factors, in the physiological activation of murine ex vivo T cells by antigen-presenting cells. Spatiotemporal patterning of these molecules was highly diverse and varied with specific T cell receptors and T cell activation conditions. The diversity and variability observed suggest that spatiotemporal patterning controls signaling interactions during T cell activation in a physiologically important and discriminating manner. In support of this, the effective clustering of a group of ligand-engaged receptors and signaling intermediates in a joint pattern consistently correlated with efficient T cell activation at the level of the whole cell.
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Affiliation(s)
- Kentner L. Singleton
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kole T. Roybal
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yi Sun
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Guo Fu
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nicholas R. J. Gascoigne
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nicolai S. C. van Oers
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Christoph Wülfing
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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216
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Abstract
CD28 is recognized as the primary costimulatory molecule involved in the activation of naïve T cells. However, the biochemical signaling pathways that are activated by CD28 and how these pathways are integrated with TCR signaling are still not understood. We have recently shown that there are at least two independent activation pathways induced by CD28 costimulation. One is integrated with TCR signaling in the context of the immunological synapse and is mediated through transcriptional enhancement and the second is mediated through the induction of mRNA stability. Here, we review the immunological consequences and biochemical mechanisms associated with CD28 costimulation and discuss the major questions that need to be resolved to understand the molecular mechanisms that transduce CD28 costimulation.
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217
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Markiewicz MA, Wise EL, Buchwald ZS, Cheney EE, Hansen TH, Suri A, Cemerski S, Allen PM, Shaw AS. IL-12 enhances CTL synapse formation and induces self-reactivity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:1351-61. [PMID: 19155481 PMCID: PMC2630174 DOI: 10.4049/jimmunol.182.3.1351] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Immunological synapse formation between T cells and target cells can affect the functional outcome of TCR ligation by a given MHC-peptide complex. Although synapse formation is usually induced by TCR signaling, it is not clear whether other factors can affect the efficiency of synapse formation. Here, we tested whether cytokines could influence synapse formation between murine CTLs and target cells. We found that IL-12 enhanced synapse formation, whereas TGFbeta decreased synapse formation. The enhanced synapse formation induced by IL-12 appeared to be functional, given that IL-12-treated cells could respond to weak peptides, including self-peptides, to which the T cells were normally unresponsive. These responses correlated with expression of functionally higher avidity LFA-1 on IL-12-treated CTLs. These findings have implications for the function of IL-12 in T cell-mediated autoimmunity.
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Affiliation(s)
- Mary A. Markiewicz
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Erica L. Wise
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zachary S. Buchwald
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth E. Cheney
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ted H. Hansen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Anish Suri
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Saso Cemerski
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Paul M. Allen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrey S. Shaw
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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218
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van de Loosdrecht AA, van den Ancker W, Houtenbos I, Ossenkoppele GJ, Westers TM. Dendritic cell-based immunotherapy in myeloid leukaemia: translating fundamental mechanisms into clinical applications. Handb Exp Pharmacol 2009:319-348. [PMID: 19031033 DOI: 10.1007/978-3-540-71029-5_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Immunotherapy for leukaemia patients, aiming at the generation of anti-leukaemic T cell responses, could provide a new therapeutic approach to eliminate minimal residual disease (MRD) cells in acute myeloid leukaemia (AML). Leukaemic blasts harbour several ways to escape the immune system including deficient MHC class II expression, low levels of co-stimulatory molecules and suppressive cytokines. Therapeutic vaccination with dendritic cells (DC) is now recognized as an important investigational therapy. Due to their unique antigen presenting capacity, immunosuppressive features of the leukaemic blasts can be circumvented. DC can be successfully cultured from leukaemic blasts in 60-70% of patients and show functional potential in vivo. Alternatively, monocyte derived DC obtained at time of complete remission loaded with leukaemia-specific antigens can be used as vaccine. Several sources of leukaemia-associated antigen and different methods of loading antigen onto DC have been used in an attempt to optimize antitumour responses including apoptotic cells, necrotic cell lysates and tumour-associated pep-tides. Currently, the AML-derived cell line MUTZ-3, an immortalized equivalent of CD34(+) DC precursor cells, is under investigation for vaccination purposes. For effective DC vaccination the intrinsic tolerant state of the patient must be overcome. Therefore, the development of efficient and safe adjuvants in antigen specific immunotherapeutic programs should be encouraged.
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Affiliation(s)
- A A van de Loosdrecht
- Department of Haematology, VU-Institute of Cancer and Immunology, VU University Medical Center, Amsterdam, De Boelelaan 1117, 1081 HV, The Netherlands.
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219
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Bonefeld CM, Haks M, Nielsen B, von Essen M, Boding L, Hansen AK, Larsen JM, Odum N, Krimpenfort P, Kruisbeek A, Christensen JP, Thomsen AR, Geisler C. TCR down-regulation controls virus-specific CD8+ T cell responses. THE JOURNAL OF IMMUNOLOGY 2008; 181:7786-99. [PMID: 19017968 DOI: 10.4049/jimmunol.181.11.7786] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the antiapoptotic molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus-specific CD8(+) T cell responses.
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Affiliation(s)
- Charlotte Menné Bonefeld
- Department of International Health, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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220
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Gutiérrez M, Ruiz Carrascosa JC. [The lymphocyte: protagonism in the new era of the biological therapies]. ACTAS DERMO-SIFILIOGRAFICAS 2008; 99 Suppl 1:2-8. [PMID: 18341848 DOI: 10.1016/s0001-7310(08)76193-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Psoriasis is a systemic type T cell mediated immune system chronic inflammatory skin disease. These cells play an important role in the immune system and in the inflammatory response that determines the development and maintenance of the psoriasis lesions. However, greater understanding of the pathophysiology of this disease has led to the development of specific and selective biological treatments. Efalizumab is a humanized IgG1 monoclonal antibody that binds to the Leukocyte-Function-Associated Antigen 1 (LFA-1). When it binds to the CD11a--alpha subunit of LFA1--it inhibits the binding of this ligand to the intercellular adhesion molecule 1. This inhibits several processes related with the T cells that are fundamental in the pathogenesis of psoriasis: activation of the T cells in the lymph nodes, the migration of the T cells towards the dermis and epidermis and finally the reactivation of these in the inflammatory focus. The clinical studies have demonstrated that efalizumab, administered subcutaneously only once a week, provides a clinical benefit as well as improvement in the quality of life in patients with psoriasis with chronic, moderate or severe plaques. Long-term treatment studies suggest that continuous therapy with efalizumab is more beneficial in the maintenance of the improvement of the response and demonstrate that efalizumab may be administered safely for prolonged periods. Given its efficacy, rapid onset action, safety profile due to its selective action mechanism and convenience in its subcutaneous self-administration weekly, efalizumab offers a new therapeutic option, especially of interest for the treatment of psoriasis.
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Affiliation(s)
- M Gutiérrez
- Servicio de Dermatología, Hospital Universitario San Cecilio, Granada, España
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221
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Dustin ML. Visualization of cell-cell interaction contacts-synapses and kinapses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 640:164-82. [PMID: 19065791 DOI: 10.1007/978-0-387-09789-3_13] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
T-cell activation requires interactions of T-cell antigen receptors (TCR) and peptides presented by major histocompatibility complex molecules (MHCp) in an adhesive junction between the T-cell and antigen-presenting cell (APC). Stable junctions with bull's eye supramolecular activation clusters (SMACs) have been defined as immunological synapses. The term synapse works in this case because it joins roots for "same" and "fasten", which could be translated as "fasten in the same place". These structures maintain T-cell-APC interaction and allow directed secretion. We have proposed that SMACs are not really clusters, but are analogous to higher order membrane-cytoskeleton zones involved in amoeboid locomotion including a substrate testing lamellipodium, an adhesive lamella and anti-adhesive uropod. Since T-cells can also integrate signaling during locomotion over antigen presenting cells, it is important to consider adhesive junctions maintained as cells move past each other. This combination of movement (kine-) and fastening (-apse) can be described as a kinapse or moving junction. Synapses and kinapses operate in different stages of T-cell priming. Optimal effector functions may also depend upon cyclical use of synapses and kinapses. Visualization of these structures in vitro and in vivo presents many distinct challenges that will be discussed in this chapter.
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Affiliation(s)
- Michael L Dustin
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine and Department of Pathology, New York University School of Medicine, 540 1st Ave, New York, NY 10016, USA.
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223
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Kao H, Lin J, Littman DR, Shaw AS, Allen PM. Regulated movement of CD4 in and out of the immunological synapse. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:8248-57. [PMID: 19050241 PMCID: PMC2857686 DOI: 10.4049/jimmunol.181.12.8248] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The mechanism underlying the transient accumulation of CD4 at the immunological synapse (IS) and its significance for T cell activation are not understood. To investigate these issues, we mutated a serine phosphorylation site (S408) in the cytoplasmic tail of murine CD4. Preventing phosphorylation of S408 did not block CD4 recruitment to the IS; rather, it blocked the ability of CD4 to leave the IS. Surprisingly, enhanced and prolonged CD4 accumulation at the supramolecular activation cluster in the contact area had no functional consequence for T cell activation, cytokine production, or proliferation. Protein kinase C theta (PKCtheta)-deficient T cells also displayed enhanced and prolonged accumulation of wild-type CD4 at the IS, indicating that theta is the critical PKC isoform involved in CD4 movement. These findings suggest a model wherein recruitment of CD4 to the IS allows its phosphorylation by PKCtheta and subsequent removal from the IS. Thus, an important role for PKCtheta in T cell activation involves its recruitment to the IS, where it phosphorylates specific substrates that help to maintain the dynamism of protein turnover at the IS.
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Affiliation(s)
- Henry Kao
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
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224
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Dushek O, Mueller S, Soubies S, Depoil D, Caramalho I, Coombs D, Valitutti S. Effects of intracellular calcium and actin cytoskeleton on TCR mobility measured by fluorescence recovery. PLoS One 2008; 3:e3913. [PMID: 19079546 PMCID: PMC2593776 DOI: 10.1371/journal.pone.0003913] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Accepted: 11/17/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The activation of T lymphocytes by specific antigen is accompanied by the formation of a specialized signaling region termed the immunological synapse, characterized by the clustering and segregation of surface molecules and, in particular, by T cell receptor (TCR) clustering. METHODOLOGY/PRINCIPAL FINDINGS To better understand TCR motion during cellular activation, we used confocal microscopy and photo-bleaching recovery techniques to investigate the lateral mobility of TCR on the surface of human T lymphocytes under various pharmacological treatments. Using drugs that cause an increase in intracellular calcium, we observed a decrease in TCR mobility that was dependent on a functional actin cytoskeleton. In parallel experiments measurement of filamentous actin by FACS analysis showed that raising intracellular calcium also causes increased polymerization of the actin cytoskeleton. These in vitro results were analyzed using a mathematical model that revealed effective binding parameters between TCR and the actin cytoskeleton. CONCLUSION/SIGNIFICANCE We propose, based on our results, that increase in intracellular calcium levels leads to actin polymerization and increases TCR/cytoskeleton interactions that reduce the overall mobility of the TCR. In a physiological setting, this may contribute to TCR re-positioning at the immunological synapse.
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Affiliation(s)
- Omer Dushek
- Department of Mathematics and Institute of Applied Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sabina Mueller
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, France
| | - Sebastien Soubies
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, France
| | - David Depoil
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, France
| | - Iris Caramalho
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, France
| | - Daniel Coombs
- Department of Mathematics and Institute of Applied Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Salvatore Valitutti
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, France
- * E-mail:
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225
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Sanchez-Lockhart M, Graf B, Miller J. Signals and sequences that control CD28 localization to the central region of the immunological synapse. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:7639-48. [PMID: 19017952 PMCID: PMC3993010 DOI: 10.4049/jimmunol.181.11.7639] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During T cell interaction with APC, CD28 is recruited to the central region (cSMAC) of the immunological synapse. CD28-mediated signaling through PI3K results in the recruitment of protein kinase C-theta (PKCtheta) to the cSMAC, activation of NF-kappaB, and up-regulation of IL-2 transcription. However, the mechanism that mediates CD28 localization to the cSMAC and the functional consequences of CD28 localization to the cSMAC are not understood. In this report, we show that CD28 recruitment and persistence at the immunological synapse requires TCR signals and CD80 engagement. Addition of mAb to either MHC class II or CD80 results in the rapid displacement of CD28 from the immunological synapse. Ligand binding is not sufficient for CD28 localization to the immunological synapse, as truncation of the cytosolic tail of CD28 disrupts synapse localization without effecting the ability of CD28 to bind CD80. Furthermore, a single point mutation in the CD28 cytosolic tail (tyrosine 188) interferes with the ability of CD28 to preferentially accumulate at the cSMAC. PKCtheta distribution at the immunological synapse mirrors the distribution of tyrosine 188-mutated CD28, indicating that CD28 drives the localization of PKCtheta even when CD28 is not localized to the cSMAC. Mutation of tyrosine 188 also results in diminished activation of NF-kappaB, suggesting that CD28-mediated localization of PKCtheta to the cSMAC is important for efficient signal transduction. These data reinforce the importance of the interplay of signals between TCR and CD28 and suggest that CD28 signaling through PCKtheta may be mediated through localization to the cSMAC region of the immunological synapse.
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MESH Headings
- Amino Acid Substitution
- Animals
- B7-1 Antigen/genetics
- B7-1 Antigen/immunology
- CD28 Antigens/genetics
- CD28 Antigens/immunology
- CD28 Antigens/metabolism
- Cell Line
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/immunology
- Histocompatibility Antigens Class II/metabolism
- Immunological Synapses/enzymology
- Immunological Synapses/genetics
- Immunological Synapses/immunology
- Interleukin-2/biosynthesis
- Interleukin-2/genetics
- Interleukin-2/immunology
- Isoenzymes/genetics
- Isoenzymes/immunology
- Isoenzymes/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic
- Mutation, Missense
- NF-kappa B/genetics
- NF-kappa B/immunology
- NF-kappa B/metabolism
- Phosphatidylinositol 3-Kinases/genetics
- Phosphatidylinositol 3-Kinases/immunology
- Phosphatidylinositol 3-Kinases/metabolism
- Protein Kinase C/genetics
- Protein Kinase C/immunology
- Protein Kinase C/metabolism
- Protein Kinase C-theta
- Protein Structure, Tertiary/genetics
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocytes/enzymology
- T-Lymphocytes/immunology
- Transcription, Genetic/genetics
- Transcription, Genetic/immunology
- Up-Regulation/genetics
- Up-Regulation/immunology
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Affiliation(s)
| | - Beth Graf
- The David H. Smith Center for Vaccine Biology and Immunology and the
| | - Jim Miller
- The David H. Smith Center for Vaccine Biology and Immunology and the
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642
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226
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Oddos S, Dunsby C, Purbhoo MA, Chauveau A, Owen DM, Neil MAA, Davis DM, French PMW. High-speed high-resolution imaging of intercellular immune synapses using optical tweezers. Biophys J 2008; 95:L66-8. [PMID: 18723590 PMCID: PMC2576363 DOI: 10.1529/biophysj.108.143198] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 08/19/2008] [Indexed: 01/23/2023] Open
Abstract
Imaging in any plane other than horizontal in a microscope typically requires a reconstruction from multiple optical slices that significantly decreases the spatial and temporal resolution that can be achieved. This can limit the precision with which molecular events can be detected, for example, at intercellular contacts. This has been a major issue for the imaging of immune synapses between live cells, which has generally required the reconstruction of en face intercellular synapses, yielding spatial resolution significantly above the diffraction limit and updating at only a few frames per minute. Strategies to address this issue have usually involved using artificial activating substrates such as antibody-coated slides or supported planar lipid bilayers, but synapses with these surrogate stimuli may not wholly resemble immune synapses between two cells. Here, we combine optical tweezers and confocal microscopy to realize generally applicable, high-speed, high-resolution imaging of almost any arbitrary plane of interest. Applied to imaging immune synapses in live-cell conjugates, this has enabled the characterization of complex behavior of highly dynamic clusters of T cell receptors at the T cell/antigen-presenting cell intercellular immune synapse and revealed the presence of numerous, highly dynamic long receptor-rich filopodial structures within inhibitory Natural Killer cell immune synapses.
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Affiliation(s)
- Stephane Oddos
- Chemical Biology Centre, Imperial College London, United Kingdom
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227
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Naumov YN, Naumova EN, Yassai MB, Kota K, Welsh RM, Selin LK. Multiple glycines in TCR alpha-chains determine clonally diverse nature of human T cell memory to influenza A virus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:7407-19. [PMID: 18981164 PMCID: PMC2646260 DOI: 10.4049/jimmunol.181.10.7407] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Detailed assessment of how the structural properties of T cell receptors affect clonal repertoires of Ag-specific cells is a prerequisite for a better understanding of human antiviral immunity. Herein we examine the alpha TCR repertoires of CD8 T cells reactive against the influenza A viral epitope M1(58-66), restricted by HLA-A2.1. Using molecular cloning, we systematically studied the impact of alpha-chain usage in the formation of T cell memory and revealed that M1(58-66)-specific, clonally diverse VB19 T cells express alpha-chains encoded by multiple AV genes with different CDR3 sizes. A unique feature of these alpha TCRs was the presence of CDR3 fitting to an AGA(G(n))GG-like amino acid motif. This pattern was consistent over time and among different individuals. Further molecular assessment of human CD4(+)CD8(-) and CD4(-)CD8(+) thymocytes led to the conclusion that the poly-Gly/Ala runs in CDR3alpha were a property of immune, but not naive, repertoires and could be attributed to influenza exposure. Repertoires of T cell memory are discussed in the context of clonal diversity, where poly-Gly/Ala runs in the CDR3 of alpha- and beta-chains might provide high levels of TCR flexibility during Ag recognition while gene-encoded CDR1 and CDR2 contribute to the fine specificity of the TCR-peptide MHC interaction.
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MESH Headings
- Adult
- Amino Acid Motifs/immunology
- CD8-Positive T-Lymphocytes/immunology
- Clone Cells
- Flow Cytometry
- Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor
- Genes, T-Cell Receptor alpha
- Glycine/immunology
- HLA-A2 Antigen/immunology
- Humans
- Immunologic Memory
- Infant
- Influenza A virus/immunology
- Middle Aged
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- Viral Matrix Proteins/immunology
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Affiliation(s)
- Yuri N Naumov
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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228
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Kabouridis PS, Jury EC. Lipid rafts and T-lymphocyte function: implications for autoimmunity. FEBS Lett 2008; 582:3711-8. [PMID: 18930053 PMCID: PMC2596348 DOI: 10.1016/j.febslet.2008.10.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/06/2008] [Accepted: 10/07/2008] [Indexed: 12/11/2022]
Abstract
Experimental evidence indicates that the mammalian cell membrane is compartmentalized. A structural feature that supports membrane segmentation implicates assemblies of selected lipids broadly referred to as lipid rafts. In T-lymphocytes, lipid rafts are implicated in signalling from the T-cell antigen receptor (TCR) and in localization and function of proteins residing proximal to the receptor. This review summarizes the current literature that deals with lipid raft involvement in T-cell activation and places particular emphasis in recent studies investigating lipid rafts in autoimmunity. The potential of lipid rafts as targets for the development of a new class of immune-modulating compounds is discussed.
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Affiliation(s)
- Panagiotis S. Kabouridis
- William Harvey Research Institute, Queen Mary’s School of Medicine & Dentistry, University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
| | - Elizabeth C. Jury
- Centre for Rheumatology, Royal Free & University College Medical School, University College London, London W1P 4JF, United Kingdom
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229
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Min CK, Bang SY, Cho BA, Choi YH, Yang JS, Lee SH, Seong SY, Kim KW, Kim S, Jung JU, Choi MS, Kim IS, Cho NH. Role of amphipathic helix of a herpesviral protein in membrane deformation and T cell receptor downregulation. PLoS Pathog 2008; 4:e1000209. [PMID: 19023411 PMCID: PMC2581436 DOI: 10.1371/journal.ppat.1000209] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 10/16/2008] [Indexed: 11/18/2022] Open
Abstract
Lipid rafts are membrane microdomains that function as platforms for signal transduction and membrane trafficking. Tyrosine kinase interacting protein (Tip) of T lymphotropic Herpesvirus saimiri (HVS) is targeted to lipid rafts in T cells and downregulates TCR and CD4 surface expression. Here, we report that the membrane-proximal amphipathic helix preceding Tip's transmembrane (TM) domain mediates lipid raft localization and membrane deformation. In turn, this motif directs Tip's lysosomal trafficking and selective TCR downregulation. The amphipathic helix binds to the negatively charged lipids and induces liposome tubulation, the TM domain mediates oligomerization, and cooperation of the membrane-proximal helix with the TM domain is sufficient for localization to lipid rafts and lysosomal compartments, especially the mutivesicular bodies. These findings suggest that the membrane-proximal amphipathic helix and TM domain provide HVS Tip with the unique ability to deform the cellular membranes in lipid rafts and to downregulate TCRs potentially through MVB formation.
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Affiliation(s)
- Chan-Ki Min
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Sun-Young Bang
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Bon-A Cho
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Yun-Hui Choi
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Jae-Seong Yang
- Department of Life Science and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Kyungbuk, Korea
| | - Sun-Hwa Lee
- Seoul National University Hospital, Innovative Research Institute for Cell Therapy, Chongno-Gu, Seoul, Korea
| | - Seung-Yong Seong
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
- Seoul National University Hospital, Innovative Research Institute for Cell Therapy, Chongno-Gu, Seoul, Korea
| | - Ki Woo Kim
- National Instrumentation Center for Environmental Management, Seoul National University, Gwanak-Gu, Seoul, Korea
| | - Sanguk Kim
- Department of Life Science and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Kyungbuk, Korea
| | - Jae Ung Jung
- Department of Molecular Microbiology and Immunology, University of Southern California School of Medicine, Los Angeles, California, United States of America
| | - Myung-Sik Choi
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Ik-Sang Kim
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
| | - Nam-Hyuk Cho
- Department of Microbiology and Immunology, College of Medicine and Institute of Endemic Diseases, Seoul National University Medical Research Center and Bundang Hospital, Seoul, Korea
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230
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Kim W, Fan YY, Barhoumi R, Smith R, McMurray DN, Chapkin RS. n-3 polyunsaturated fatty acids suppress the localization and activation of signaling proteins at the immunological synapse in murine CD4+ T cells by affecting lipid raft formation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:6236-43. [PMID: 18941214 PMCID: PMC2597670 DOI: 10.4049/jimmunol.181.9.6236] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The molecular properties of immunosuppressive n-3 polyunsaturated fatty acids (PUFA) have not been fully elucidated. Using CD4(+) T cells from wild-type control and fat-1 transgenic mice (enriched in n-3 PUFA), we show that membrane raft accumulation assessed by Laurdan (6-dodecanoyl-2-dimethyl aminonaphthalene) labeling was enhanced in fat-1 cells following immunological synapse (IS) formation by CD3-specific Ab expressing hybridoma cells. However, the localization of protein kinase Ctheta, phospholipase Cgamma-1, and F-actin into the IS was suppressed. In addition, both the phosphorylation status of phospholipase Cgamma-1 at the IS and cell proliferation as assessed by CFSE labeling and [(3)H]thymidine incorporation were suppressed in fat-1 cells. These data imply that lipid rafts may be targets for the development of dietary agents for the treatment of autoimmune and chronic inflammatory diseases.
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Affiliation(s)
- Wooki Kim
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843, USA
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231
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Abstract
The functional role of molecular clustering in the center of the immunological synapse is controversial. In this issue of Immunity, Cemerski et al. (2008) report that the synapse center can serve as a major site of sustained signal transduction.
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Affiliation(s)
- Salvatore Valitutti
- INSERM, U563, Centre de Physiopathologie de Toulouse Purpan, Section Dynamique moléculaire des interactions lymphocytaires, Toulouse, F-31300 France
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232
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Martín-Cófreces NB, Robles-Valero J, Cabrero JR, Mittelbrunn M, Gordón-Alonso M, Sung CH, Alarcón B, Vázquez J, Sánchez-Madrid F. MTOC translocation modulates IS formation and controls sustained T cell signaling. ACTA ACUST UNITED AC 2008; 182:951-62. [PMID: 18779373 PMCID: PMC2528574 DOI: 10.1083/jcb.200801014] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The translocation of the microtubule-organizing center (MTOC) toward the nascent immune synapse (IS) is an early step in lymphocyte activation initiated by T cell receptor (TCR) signaling. The molecular mechanisms that control the physical movement of the lymphocyte MTOC remain largely unknown. We have studied the role of the dynein–dynactin complex, a microtubule-based molecular motor, in the process of T cell activation during T cell antigen–presenting cell cognate immune interactions. Impairment of dynein–dynactin complex activity, either by overexpressing the p50-dynamitin component of dynactin to disrupt the complex or by knocking down dynein heavy chain expression to prevent its formation, inhibited MTOC translocation after TCR antigen priming. This resulted in a strong reduction in the phosphorylation of molecules such as ζ chain–associated protein kinase 70 (ZAP70), linker of activated T cells (LAT), and Vav1; prevented the supply of molecules to the IS from intracellular pools, resulting in a disorganized and dysfunctional IS architecture; and impaired interleukin-2 production. Together, these data reveal MTOC translocation as an important mechanism underlying IS formation and sustained T cell signaling.
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Affiliation(s)
- Noa B Martín-Cófreces
- Servicio de Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid, 28006 Madrid, Spain
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233
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Raychaudhuri S, Willgohs E, Nguyen TN, Khan EM, Goldkorn T. Monte Carlo simulation of cell death signaling predicts large cell-to-cell stochastic fluctuations through the type 2 pathway of apoptosis. Biophys J 2008; 95:3559-62. [PMID: 18641073 PMCID: PMC2553141 DOI: 10.1529/biophysj.108.135483] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Apoptosis, or genetically programmed cell death, is a crucial cellular process that maintains the balance between life and death in cells. The precise molecular mechanism of apoptosis signaling and the manner in which type 1 and type 2 pathways of the apoptosis signaling network are differentially activated under distinct apoptotic stimuli is poorly understood. Based on Monte Carlo stochastic simulations, we show that the type 1 pathway becomes activated under strong apoptotic stimuli, whereas the type 2 mitochondrial pathway dominates apoptotic signaling in response to a weak death signal. Our results also show signaling in the type 2 pathway is stochastic; the population average over many cells does not capture the cell-to-cell fluctuations in the time course (approximately 1-10 h) of downstream caspase-3 activation. On the contrary, the probability distribution of caspase-3 activation for the mitochondrial pathway shows a distinct bimodal behavior that can be used to characterize the stochastic signaling in type 2 apoptosis and other similar complex signaling processes. Interestingly, such stochastic fluctuations in apoptosis signaling occur even in the presence of large numbers of signaling molecules.
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Affiliation(s)
- Subhadip Raychaudhuri
- Department of Biomedical Engineering, University of California, Davis, California, USA.
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234
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MacNeil AJ, Pohajdak B. Getting aGRASPon CASP: properties and role of the cytohesin‐associated scaffolding protein in immunity. Immunol Cell Biol 2008; 87:72-80. [DOI: 10.1038/icb.2008.71] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Adam J MacNeil
- Department of Biology, Dalhousie University Nova Scotia Halifax Canada
| | - Bill Pohajdak
- Department of Biology, Dalhousie University Nova Scotia Halifax Canada
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235
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Cemerski S, Das J, Giurisato E, Markiewicz MA, Allen PM, Chakraborty AK, Shaw AS. The balance between T cell receptor signaling and degradation at the center of the immunological synapse is determined by antigen quality. Immunity 2008; 29:414-22. [PMID: 18760640 PMCID: PMC3962836 DOI: 10.1016/j.immuni.2008.06.014] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 05/26/2008] [Accepted: 06/27/2008] [Indexed: 12/31/2022]
Abstract
The role of the center of the immunological synapse (the central supramolecular activation cluster or cSMAC) is controversial. One model suggests that the role of the cSMAC depends on antigen quality and can both enhance signaling and receptor downregulation, whereas a second model proposes that the sole function of the cSMAC is to downregulate signaling. An important distinction between the models is whether signaling occurs in the cSMAC. Here, we demonstrate that at early time points, signaling occurs outside the cSMAC, but occurs in the cSMAC at later time points. Additionally, we show that cSMAC formation enhances the stimulatory potency of weak agonists for the TCR. Combined with previous studies showing that cSMAC formation decreases the signaling by strong agonists, our data support a model proposing that signaling and receptor degradation both occur in the cSMAC and that the balance between signaling and degradation in the synapse is determined by antigen quality.
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Affiliation(s)
- Saso Cemerski
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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236
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He HT, Marguet D. T-cell antigen receptor triggering and lipid rafts: a matter of space and time scales. Talking Point on the involvement of lipid rafts in T-cell activation. EMBO Rep 2008; 9:525-30. [PMID: 18516087 DOI: 10.1038/embor.2008.78] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 04/21/2008] [Indexed: 11/09/2022] Open
Abstract
T-cell antigen receptor triggering mechanisms and lipid rafts are of broad interest, but are also controversial topics. Here, we review some recent progress in these two research fields, which has been accomplished mostly in live cells and with the use of advanced technologies. We then discuss the potential relationship between membrane-domain organization and T-cell antigen receptor-triggering mechanisms. On the basis of the relevant experimental observations, we argue that the key to achieving a better understanding of both processes is the ability to monitor the molecular dynamics and interactions taking place in the membrane of T cells at a spatial scale of tens to hundreds of nanometres, with a subsecond-to-second temporal resolution.
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Affiliation(s)
- Hai-Tao He
- Centre d'Immunologie de Marseille-Luminy, Case 906, F13288 Marseille Cedex 09, France.
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237
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Abstract
The natural killer (NK)-cell immunological synapse is the dynamic interface formed between an NK cell and its target cell. Formation of the NK-cell immunological synapse involves several distinct stages, from the initiation of contact with a target cell to the directed delivery of lytic-granule contents for target-cell lysis. Progression through the individual stages is regulated, and this tight regulation underlies the precision with which NK cells select and kill susceptible target cells (including virally infected cells and cancerous cells) that they encounter during their routine surveillance of the body.
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Affiliation(s)
- Jordan S Orange
- University of Pennsylvania School of Medicine, Joseph Stokes Jr Research Institute of The Children's Hospital of Philadelphia, 3615 Civic Center Boulevard, ARC 1016H, Philadelphia, Pennsylvania 19104, USA.
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238
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Wernimont SA, Cortesio CL, Simonson WT, Huttenlocher A. Adhesions ring: a structural comparison between podosomes and the immune synapse. Eur J Cell Biol 2008; 87:507-15. [PMID: 18343530 PMCID: PMC2570187 DOI: 10.1016/j.ejcb.2008.01.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Revised: 01/16/2008] [Accepted: 01/16/2008] [Indexed: 11/30/2022] Open
Abstract
Podosomes and the immune synapse are integrin-mediated adhesive structures that share a common ring-like morphology. Both podosomes and immune synapses have a central core surrounded by a peripheral ring containing talin, vinculin and paxillin. Recent progress suggests significant parallels between the regulatory mechanisms that contribute to the formation of these adhesive structures. In this review, we compare the structures, functions and regulation of podosomes and the immune synapse.
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Affiliation(s)
- Sarah A. Wernimont
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - Christa L. Cortesio
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - William T.N. Simonson
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
| | - Anna Huttenlocher
- Medical Microbiology and Immunology and Pediatrics, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI 53706, USA
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239
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Barcia C, Sanderson NSR, Barrett RJ, Wawrowsky K, Kroeger KM, Puntel M, Liu C, Castro MG, Lowenstein PR. T cells' immunological synapses induce polarization of brain astrocytes in vivo and in vitro: a novel astrocyte response mechanism to cellular injury. PLoS One 2008; 3:e2977. [PMID: 18714338 PMCID: PMC2496894 DOI: 10.1371/journal.pone.0002977] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Accepted: 07/17/2008] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Astrocytes usually respond to trauma, stroke, or neurodegeneration by undergoing cellular hypertrophy, yet, their response to a specific immune attack by T cells is poorly understood. Effector T cells establish specific contacts with target cells, known as immunological synapses, during clearance of virally infected cells from the brain. Immunological synapses mediate intercellular communication between T cells and target cells, both in vitro and in vivo. How target virally infected astrocytes respond to the formation of immunological synapses established by effector T cells is unknown. FINDINGS Herein we demonstrate that, as a consequence of T cell attack, infected astrocytes undergo dramatic morphological changes. From normally multipolar cells, they become unipolar, extending a major protrusion towards the immunological synapse formed by the effector T cells, and withdrawing most of their finer processes. Thus, target astrocytes become polarized towards the contacting T cells. The MTOC, the organizer of cell polarity, is localized to the base of the protrusion, and Golgi stacks are distributed throughout the protrusion, reaching distally towards the immunological synapse. Thus, rather than causing astrocyte hypertrophy, antiviral T cells cause a major structural reorganization of target virally infected astrocytes. CONCLUSIONS Astrocyte polarization, as opposed to hypertrophy, in response to T cell attack may be due to T cells providing a very focused attack, and thus, astrocytes responding in a polarized manner. A similar polarization of Golgi stacks towards contacting T cells was also detected using an in vitro allogeneic model. Thus, different T cells are able to induce polarization of target astrocytes. Polarization of target astrocytes in response to immunological synapses may play an important role in regulating the outcome of the response of astrocytes to attacking effector T cells, whether during antiviral (e.g. infected during HIV, HTLV-1, HSV-1 or LCMV infection), anti-transplant, autoimmune, or anti-tumor immune responses in vivo and in vitro.
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Affiliation(s)
- Carlos Barcia
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Nicholas S. R. Sanderson
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Robert J. Barrett
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Kolja Wawrowsky
- Department of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Kurt M. Kroeger
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Mariana Puntel
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Chunyan Liu
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Maria G. Castro
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Pedro R. Lowenstein
- Board of Governors' Gene Therapeutics Research Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Department of Medicine, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Molecular and Medical Pharmacology, The Brain Research Institute, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
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240
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Kirchhof MG, Chau LA, Lemke CD, Vardhana S, Darlington PJ, Márquez ME, Taylor R, Rizkalla K, Blanca I, Dustin ML, Madrenas J. Modulation of T cell activation by stomatin-like protein 2. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:1927-36. [PMID: 18641330 PMCID: PMC2913160 DOI: 10.4049/jimmunol.181.3.1927] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
T cell activation through the Ag receptor (TCR) requires sustained signaling from signalosomes within lipid raft microdomains in the plasma membrane. In a proteomic analysis of lipid rafts from human T cells, we identified stomatin-like protein (SLP)-2 as a candidate molecule involved in T cell activation through the Ag receptor. In this study, we show that SLP-2 expression in human primary lymphocytes is up-regulated following in vivo and ex vivo activation. In activated T cells, SLP-2 interacts with components of TCR signalosomes and with polymerized actin. More importantly, up-regulation of SLP-2 expression in human T cell lines and primary peripheral blood T cells increases effector responses, whereas down-regulation of SLP-2 expression correlates with loss of sustained TCR signaling and decreased T cell activation. Our data suggest that SLP-2 is an important player in T cell activation by ensuring sustained TCR signaling, which is required for full effector T cell differentiation, and point to SLP-2 as a potential target for immunomodulation.
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Affiliation(s)
- Mark G Kirchhof
- The FOCIS Centre for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, the University of Western Ontario, London ON, Canada N6A 5K8
| | - Luan A. Chau
- The FOCIS Centre for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, the University of Western Ontario, London ON, Canada N6A 5K8
| | - Caitlin D. Lemke
- The FOCIS Centre for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, the University of Western Ontario, London ON, Canada N6A 5K8
| | - Santosh Vardhana
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, NY 10021, USA
| | - Peter J. Darlington
- The FOCIS Centre for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, the University of Western Ontario, London ON, Canada N6A 5K8
| | - Maria E. Márquez
- Instituto de Inmunologia, Universidad Central de Venezuela, Caracas, Venezuela
| | - Roy Taylor
- Department of Pathology, London Health Sciences Centre, London, ON, Canada N6A 5K8
| | - Kamilia Rizkalla
- Department of Pathology, London Health Sciences Centre, London, ON, Canada N6A 5K8
| | - Isaac Blanca
- Instituto de Inmunologia, Universidad Central de Venezuela, Caracas, Venezuela
| | - Michael L. Dustin
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, NY 10021, USA
| | - Joaquín Madrenas
- The FOCIS Centre for Clinical Immunology and Immunotherapeutics, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, the University of Western Ontario, London ON, Canada N6A 5K8
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241
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Nguyen K, Sylvain NR, Bunnell SC. T cell costimulation via the integrin VLA-4 inhibits the actin-dependent centralization of signaling microclusters containing the adaptor SLP-76. Immunity 2008; 28:810-21. [PMID: 18549800 DOI: 10.1016/j.immuni.2008.04.019] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 12/07/2007] [Accepted: 04/08/2008] [Indexed: 01/29/2023]
Abstract
Antigen-dependent T cell activation drives the formation of signaling microclusters containing the adaptor SLP-76. Costimulatory integrins regulate SLP-76 phosphorylation and could influence SLP-76 microclusters in the integrin-rich periphery of the immune synapse. We report that costimulation by the integrin VLA-4 (alpha4beta1) required SLP-76 domains implicated in microcluster assembly. Pro-adhesive ligands enlarged the contact and increased the number of SLP-76 microclusters regardless of their costimulatory potential. Costimulatory VLA-4 ligands also prevented the centralization of SLP-76, promoted microcluster persistence, prolonged lateral interactions between SLP-76 and its upstream kinase, ZAP-70, and retained SLP-76 in tyrosine-phosphorylated peripheral structures. SLP-76 centralization was driven by dynamic actin polymerization and was correlated with inward actin flows. VLA-4 ligation retarded these flows, even in the absence of SLP-76. These data suggest a widely applicable model of costimulation, in which integrins promote sustained signaling by attenuating cytoskeletal movements that drive the centralization and inactivation of SLP-76 microclusters.
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Affiliation(s)
- Ken Nguyen
- Program in Immunology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
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242
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Abstract
Integrin engagement costimulates T cell receptor signaling, but the underlying mechanisms are poorly understood. In this issue of Immunity, Nguyen et al. (2008) show that engagement of VLA-4 promotes sustained signaling by altering the dynamics of actin filaments and signaling molecules at the immunological synapse.
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Affiliation(s)
- Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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243
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Thauland TJ, Koguchi Y, Wetzel SA, Dustin ML, Parker DC. Th1 and Th2 cells form morphologically distinct immunological synapses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:393-9. [PMID: 18566405 PMCID: PMC2441916 DOI: 10.4049/jimmunol.181.1.393] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The arrangement of molecules at the interface between T cells and APCs is known as the immunological synapse (IS). We conducted experiments with supported planar bilayers and transfected fibroblast APC to examine the IS formed by polarized Th1 and Th2 cells. Th1 cells formed typical "bull's-eye" IS with a ring of adhesion molecules surrounding MHC/TCR interactions at all Ag concentrations tested, while Th2 cells formed multifocal IS at high concentrations of Ag. At low Ag concentrations, the majority of Th2 cells formed IS with a compact, central accumulation of MHC/TCR, but ICAM-1 was not excluded from the center of the IS. Additionally, CD45 was excluded from the center of the interface between Th1 cells and APC, while CD45 was found at the center of the multifocal IS formed by Th2 cells. Finally, phosphorylated signaling molecules colocalized with MHC/TCR to a greater extent in Th2 IS. Together, our results indicate that the IS formed by Th1 and Th2 cells are distinct in structure, with Th2 cells failing to form bull's-eye IS.
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Affiliation(s)
- Timothy J. Thauland
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239
| | - Yoshinobu Koguchi
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239
| | - Scott A. Wetzel
- Division of Biological Sciences and Center for Environmental Health Sciences, University of Montana, Missoula, MT 59812
| | - Michael L. Dustin
- Department of Pathology and the Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, NY 10016
| | - David C. Parker
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239
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244
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Abstract
T cell cytoarchitecture differs dramatically depending on whether the cell is circulating within the bloodstream, migrating through tissues, or interacting with antigen-presenting cells. The transition between these states requires important signaling-dependent changes in actin cytoskeletal dynamics. Recently, analysis of actin-regulatory proteins associated with T cell activation has provided new insights into how T cells control actin dynamics in response to external stimuli and how actin facilitates downstream signaling events and effector functions. Among the actin-regulatory proteins that have been identified are nucleation-promoting factors such as WASp, WAVE2, and HS1; severing proteins such as cofilin; motor proteins such as myosin II; and linker proteins such as ezrin and moesin. We review the current literature on how signaling pathways leading from diverse cell surface receptors regulate the coordinated activity of these and other actin-regulatory proteins and how these proteins control T cell function.
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Affiliation(s)
- Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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245
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Abstract
The transition from rolling to firm adhesion is a key step in the adhesion cascade that permits a neutrophil to exit the bloodstream and make its way to a site of inflammation. In this work, we construct an integrated model of neutrophil activation and arrest that combines a biomechanical model of neutrophil adhesion and adhesive dynamics, with fully stochastic signal transduction modeling, in the form of kinetic Monte Carlo simulation within the microvilli. We employ molecular binding parameters gleaned from the literature and from simulation of cell-free rolling mediated by selectin molecules. We create a simplified model of lymphocyte function-associated antigen-1 activation that links P-selectin glycoprotein ligand-1 ligation to integrin activation. The model utilizes an energy profile of various integrin activation states drawn from literature data and permits manipulation of signal diffusivity within the microvillus. Our integrated model recreates neutrophil arrest within physiological timescales, and we demonstrate that increasing signal diffusivity within a microvillus accelerates arrest. If the energy barrier between free unactivated and free activated lymphocyte function-associated antigen-1 increases, the period of rolling before arrest increases. We further demonstrate that, within our model, modification of endothelial ligand surface densities can control arrest. In addition, the relative concentrations of signaling molecules control the fractional activation of the overall signaling pathway and the rolling time to arrest. This work presents the first, to our knowledge, fully stochastic model of neutrophil activation, which, though simplified, can recapitulate significant physiological details of neutrophil arrest yet retains the capacity to incorporate additional information regarding mechanisms of neutrophil signal transduction as they are elucidated.
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246
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Valenzuela-Fernández A, Cabrero JR, Serrador JM, Sánchez-Madrid F. HDAC6: a key regulator of cytoskeleton, cell migration and cell-cell interactions. Trends Cell Biol 2008; 18:291-7. [PMID: 18472263 DOI: 10.1016/j.tcb.2008.04.003] [Citation(s) in RCA: 396] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 04/02/2008] [Accepted: 04/03/2008] [Indexed: 11/26/2022]
Abstract
Histone deacetylase 6 (HDAC6) is a cytoplasmic enzyme that regulates many important biological processes, including cell migration, immune synapse formation, viral infection, and the degradation of misfolded proteins. HDAC6 deacetylates tubulin, Hsp90 and cortactin, and forms complexes with other partner proteins. Although HDAC6 enzymatic activity seems to be required for the regulation of cell morphology, the role of HDAC6 in lymphocyte chemotaxis is independent of its tubulin deacetylase activity. The diverse functions of HDAC6 suggest that it is a potential therapeutic target for the treatment of a range of diseases. This review examines the biological actions of HDAC6, focusing on its deacetylase activity and its potential scaffold functions in the regulation of cell migration and other key biological processes in which the cytoskeleton plays an important role.
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Affiliation(s)
- Agustín Valenzuela-Fernández
- Departamento de Medicina Física y Farmacología, Facultad de Medicina and Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
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247
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Monte Carlo study of single molecule diffusion can elucidate the mechanism of B cell synapse formation. Biophys J 2008; 95:1118-25. [PMID: 18456833 DOI: 10.1529/biophysj.107.122564] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
B cell receptors have been shown to cluster at the intercellular junction between a B cell and an antigen-presenting cell in the form of a segregated pattern of B cell receptor/antigen complexes known as an immunological synapse. We use random walk-based theoretical arguments and Monte Carlo simulations to study the effect of diffusion of surface-bound molecules on B cell synapse formation. Our results show that B cell synapse formation is optimal for a limited range of receptor-ligand complex diffusion coefficient values, typically one-to-two orders of magnitude lower than the diffusion coefficient of free receptors. Such lower mobility of receptor-ligand complexes can significantly affect the diffusion of a tagged receptor or ligand in an affinity dependent manner, as the binding/unbinding of such receptor or ligand molecules crucially depends on affinity. Our work shows how single molecule tracking experiments can be used to estimate the order of magnitude of the diffusion coefficient of receptor-ligand complexes, which is difficult to measure directly in experiments due to the finite lifetime of receptor-ligand bonds. We also show how such antigen movement data at the single molecule level can provide insight into the B cell synapse formation mechanism. Thus, our results can guide further single molecule tracking experiments to elucidate the synapse formation mechanism in B cells, and potentially in other immune cells.
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Perl A, Nagy G, Koncz A, Gergely P, Fernandez D, Doherty E, Telarico T, Bonilla E, Phillips PE. Molecular mimicry and immunomodulation by the HRES-1 endogenous retrovirus in SLE. Autoimmunity 2008; 41:287-97. [PMID: 18432409 PMCID: PMC5294745 DOI: 10.1080/08916930802024764] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Genetic and environmental factors are believed to influence development of systemic lupus erythematosus (SLE). Endogenous retroviruses (ERV) correspond to the integrated proviral form of infectious retroviruses, which are trapped within the genome due to mutations. ERV represent a key molecular link between the host genome and infectious viral particles. ERV-encoded proteins are recognized by antiviral immune responses and become targets of autoreactivity. Alternatively, ERV protein may influence cellular processes and the life cycle of infectious viruses. As examples, the HRES-1 human ERV encodes a 28-kDa nuclear autoantigen and a 24-kDa small GTP-ase, termed HRES-1/Rab4. HRES-1/p28 is a nuclear autoantigen recognized by cross-reactive antiviral antibodies, while HRES-1/Rab4 regulates surface expression of CD4 and the transferrin receptor (TFR) through endosome recycling. Expression of HRES-1/Rab4 is induced by the tat gene of HIV-1, which in turn down-regulates expression of CD4 and susceptibility to re-infection by HIV-1. CD4 and the TFR play essential roles in formation of the immunological synapse (IS) during normal T-cell activation by a cognate MHC class II peptide complex. The key intracellular transducer of T-cell activation, Lck, is brought to the IS via binding to CD4. T-cell receptorzeta (TCRzeta) chain binds to the TFR. Abnormal T-cell responses in SLE have been associated with reduced lck and TCRzeta chain levels. HRES-1 is centrally located on chromosome 1 at q42 relative to lupus-linked microsatellite markers and polymorphic HRES-1 alleles have been linked to the development of SLE. 1q42 is one of the three most common fragile sites in the human genome, and is inducible by DNA demethylation, a known mechanism of retroviral gene activation. Molecular mimicry and immunomodulation by a ERV, such as HRES-1, may contribute to self-reactivity and abnormal T and B-cell functions in SLE.
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Affiliation(s)
- Andras Perl
- Division of Rheumatology, Department of Medicine, State University of New York Upstate Medical University, Syracuse, NY 13210, USA.
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Malherbe L, Mark L, Fazilleau N, McHeyzer-Williams LJ, McHeyzer-Williams MG. Vaccine adjuvants alter TCR-based selection thresholds. Immunity 2008; 28:698-709. [PMID: 18450485 PMCID: PMC2695494 DOI: 10.1016/j.immuni.2008.03.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 02/29/2008] [Accepted: 03/06/2008] [Indexed: 12/26/2022]
Abstract
How T cell receptor (TCR) specificity evolves in vivo after protein vaccination is central to the development of helper T (Th) cell function. Most models of clonal selection in the Th cell compartment favor TCR affinity-based thresholds. Here, we demonstrated that depot-forming vaccine adjuvants did not require Toll-like receptor (TLR) agonists to induce clonal dominance in antigen-specific Th cell responses. However, readily dispersible adjuvants using TLR-9 and TLR-4 agonists skewed TCR repertoire usage by increasing TCR selection thresholds and enhancing antigen-specific clonal expansion. In this manner, vaccine adjuvants control the local accumulation of Th cells expressing TCR with the highest peptide MHC class II binding. Clonal composition was altered by mechanisms that blocked the local propagation of clonotypes independently of antigen dose and not as a consequence of interclonal competition. This capacity of adjuvants to modify antigen-specific Th cell clonal composition has fundamental implications for the design of future protein subunit vaccines.
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MESH Headings
- Adjuvants, Immunologic
- Animals
- Cytochromes c/immunology
- Cytochromes c/metabolism
- Lymphocyte Activation
- Mice
- Mice, Congenic
- Mice, Transgenic
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- T-Lymphocytes, Helper-Inducer/immunology
- T-Lymphocytes, Helper-Inducer/metabolism
- Toll-Like Receptors/agonists
- Toll-Like Receptors/immunology
- Toll-Like Receptors/metabolism
- Vaccines/immunology
- Vaccines, Subunit/immunology
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Affiliation(s)
- Laurent Malherbe
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Abstract
T-cell activation requires 'contact' with antigen-presenting cells (APCs) to bring the T-cell receptor (TCR) and antigenic major histocompatibility complex (MHC)-peptide complex together. Contact is defined by the size of the TCR and MHC-peptide complex, which at approximately 13 nm requires extensive interdigitation of the glycocalyx of the T cell and APC. T cells may be activated through formation of a stable T cell-APC junction, referred to as an immunological synapse. It has also been shown in vitro that T cells can integrate signals from APCs without a stable interaction. In vivo imaging studies supported the importance of both motile and stable T cell-APC interactions in T-cell priming. We have found that stability depends not upon turning off motile machinery but by symmetrization of force-generating structures to balance forces and hold the cell in place. Motility is induced by breaking this symmetry, which may be necessary to maintain the differentiation potential of the T cell. Recently, we also discovered a mode of T-cell signaling leading to tolerance in vivo based purely on motile interactions. Because this entire process takes place in a state of continuous T-cell kinesis, I propose the term 'kinapse' for motile T cell-APC contacts leading to signaling. Synapses and kinapses are inter-convertible by symmetrization/symmetry breaking processes, and both modes appear to be involved in normal T-cell priming. Imbalance of synapse/kinapse states may lead to immunopathology.
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Affiliation(s)
- Michael L Dustin
- Helen and Martin Kimmel Center for Biology and Medicine of the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
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