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  1. Article ; Online: Regulation of T-cell receptor signaling by the actin cytoskeleton and poroelastic cytoplasm.

    Beemiller, Peter / Krummel, Matthew F

    Immunological reviews

    2013  Volume 256, Issue 1, Page(s) 148–159

    Abstract: The actin cytoskeleton plays essential roles in modulating T-cell activation. Most models of T-cell receptor (TCR) triggering signalosome assembly and immune synapse formation invoke actin-dependent mechanisms. As T cells are constitutively motile cells, ...

    Abstract The actin cytoskeleton plays essential roles in modulating T-cell activation. Most models of T-cell receptor (TCR) triggering signalosome assembly and immune synapse formation invoke actin-dependent mechanisms. As T cells are constitutively motile cells, TCR triggering and signaling occur against a cytoskeletal backdrop that is constantly remodeling. While the interplay between actin dynamics and TCR signaling have been the focus of research for many years, much of the work in T cells has considered actin largely for its 'scaffolding' function. We examine the roles of the actin cytoskeleton in TCR signaling and immune synapse formation with an emphasis on how poroelasticity, an ensemble feature of actin dynamics with the cytosol, relates to how T cells respond to stimulation.
    MeSH term(s) Actin Cytoskeleton/metabolism ; Animals ; Cytoplasm/metabolism ; Humans ; Immunological Synapses/metabolism ; Receptors, Antigen, T-Cell/metabolism ; Signal Transduction ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism
    Chemical Substances Receptors, Antigen, T-Cell
    Language English
    Publishing date 2013-10-09
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 391796-4
    ISSN 1600-065X ; 0105-2896
    ISSN (online) 1600-065X
    ISSN 0105-2896
    DOI 10.1111/imr.12120
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Mediation of T-cell activation by actin meshworks.

    Beemiller, Peter / Krummel, Matthew F

    Cold Spring Harbor perspectives in biology

    2010  Volume 2, Issue 9, Page(s) a002444

    Abstract: Although the actin cytoskeleton and T-cell receptor (TCR) signaling complexes are seemingly distinct molecular structures, they are tightly integrated in T cells. The signaling pathways initiated by TCRs binding to peptide MHC complexes are extensively ... ...

    Abstract Although the actin cytoskeleton and T-cell receptor (TCR) signaling complexes are seemingly distinct molecular structures, they are tightly integrated in T cells. The signaling pathways initiated by TCRs binding to peptide MHC complexes are extensively influenced by the actin cytoskeletal activities of the motile phase before TCR signaling, the signalosome scaffolding function of the cytoskeleton, and the translocation of signaling clusters that precedes the termination of signaling at these complexes. As these three successive phases constitute essentially all the steps consequent to immune synapse formation, it has become clear that the substantial physical forces and signaling interactions generated by the actin cytoskeleton dominate the signaling life cycle of TCR signalosomes. We discuss the contributions of the actin cytoskeleton to TCR signaling phases and model some remaining questions about how specific cytoskeletal factors regulate TCR signaling outcomes.
    MeSH term(s) Actins/immunology ; Cell Movement/immunology ; Cytoskeleton/immunology ; Histocompatibility Antigens/immunology ; Humans ; Lymphocyte Activation ; Receptors, Antigen, T-Cell/immunology ; Signal Transduction ; T-Lymphocytes/immunology
    Chemical Substances Actins ; Histocompatibility Antigens ; Receptors, Antigen, T-Cell
    Language English
    Publishing date 2010-08-11
    Publishing country United States
    Document type Journal Article ; Review
    ISSN 1943-0264
    ISSN (online) 1943-0264
    DOI 10.1101/cshperspect.a002444
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Distinct functions for HS1 in chemosensory versus adhesive signaling.

    Beemiller, Peter / Krummel, Matthew F

    Nature immunology

    2008  Volume 9, Issue 8, Page(s) 833–834

    MeSH term(s) Blood Proteins/metabolism ; Phosphorylation ; Protein-Tyrosine Kinases/metabolism ; Signal Transduction/immunology ; Signal Transduction/physiology
    Chemical Substances Blood Proteins ; HCLS1 protein, human ; Protein-Tyrosine Kinases (EC 2.7.10.1)
    Language English
    Publishing date 2008-08
    Publishing country United States
    Document type Comment ; News
    ZDB-ID 2016987-5
    ISSN 1529-2916 ; 1529-2908
    ISSN (online) 1529-2916
    ISSN 1529-2908
    DOI 10.1038/ni0808-833
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Integration of the movement of signaling microclusters with cellular motility in immunological synapses.

    Beemiller, Peter / Jacobelli, Jordan / Krummel, Matthew F

    Nature immunology

    2012  Volume 13, Issue 8, Page(s) 787–795

    Abstract: Immune synapses form between T cells and antigen-presenting cells (APCs). Increasing evidence suggests synapses must form flexibly to accommodate ongoing motility and displacement of the synapse. Here, time-lapse total internal reflection fluorescence ( ... ...

    Abstract Immune synapses form between T cells and antigen-presenting cells (APCs). Increasing evidence suggests synapses must form flexibly to accommodate ongoing motility and displacement of the synapse. Here, time-lapse total internal reflection fluorescence (TIRF) microscopy showed that signaling via the T cell antigen receptor (TCR) occurred during synapse translation. TCR microclusters in motile synapses did not flow directly into supramolecular activating complexes (SMACs) but were directed, independently of myosin II contractility, toward an F-actin-poor 'sink' region. Inward microcluster flow often followed collapse of the leading edge, which suggested that actin depolymerization regulated microcluster flow and the formation of SMACs. The coordination of TCR movement with the translocation of this 'sink' shows how T cells coordinate TCR signaling and microcluster flow in dynamic physiological synapses.
    MeSH term(s) Actins/metabolism ; Animals ; Antigen-Presenting Cells/immunology ; Antigen-Presenting Cells/metabolism ; Cell Communication ; Cell Membrane/immunology ; Cell Movement/immunology ; Cells, Cultured ; Immunological Synapses/immunology ; Lipid Bilayers/metabolism ; Lymphocyte Activation ; Mice ; Mice, Transgenic ; Microscopy, Fluorescence ; Myosin Type II/metabolism ; Receptors, Antigen, T-Cell/biosynthesis ; Receptors, Antigen, T-Cell/immunology ; Receptors, Antigen, T-Cell/metabolism ; Signal Transduction ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism
    Chemical Substances Actins ; Lipid Bilayers ; Receptors, Antigen, T-Cell ; Myosin Type II (EC 3.6.1.-)
    Language English
    Publishing date 2012-07-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2016987-5
    ISSN 1529-2916 ; 1529-2908
    ISSN (online) 1529-2916
    ISSN 1529-2908
    DOI 10.1038/ni.2364
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Assessing and benchmarking multiphoton microscopes for biologists.

    Corbin, Kaitlin / Pinkard, Henry / Peck, Sebastian / Beemiller, Peter / Krummel, Matthew F

    Methods in cell biology

    2014  Volume 123, Page(s) 135–151

    Abstract: Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors ... ...

    Abstract Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors and electronics, contribute to the overall ability of these microscopes to excite and detect fluorescence deep within tissues. However, we have found that there are few standard ways already described in the literature to distinguish between microscopes or to benchmark existing microscopes to measure the overall quality and efficiency of these instruments. Here, we discuss some simple parameters and methods that can either be used within a multiphoton facility or by a prospective purchaser to benchmark performance. This can both assist in identifying decay in microscope performance and in choosing features of a scope that are suited to experimental needs.
    MeSH term(s) Benchmarking ; Cells, Cultured ; Green Fluorescent Proteins/biosynthesis ; Green Fluorescent Proteins/chemistry ; Humans ; Microscopy, Fluorescence, Multiphoton/instrumentation ; Microscopy, Fluorescence, Multiphoton/standards ; Signal-To-Noise Ratio ; Single-Cell Analysis/instrumentation ; Single-Cell Analysis/standards
    Chemical Substances Green Fluorescent Proteins (147336-22-9)
    Language English
    Publishing date 2014-06-25
    Publishing country United States
    Document type Journal Article
    ISSN 0091-679X
    ISSN 0091-679X
    DOI 10.1016/B978-0-12-420138-5.00008-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Evolving immune circuits are generated by flexible, motile, and sequential immunological synapses.

    Gérard, Audrey / Beemiller, Peter / Friedman, Rachel S / Jacobelli, Jordan / Krummel, Matthew F

    Immunological reviews

    2012  Volume 251, Issue 1, Page(s) 80–96

    Abstract: The immune system is made up of a diverse collection of cells, each of which has distinct sets of triggers that elicit unique and overlapping responses. It is correctly described as a 'system' because its overall properties (e.g. 'tolerance', 'allergy') ... ...

    Abstract The immune system is made up of a diverse collection of cells, each of which has distinct sets of triggers that elicit unique and overlapping responses. It is correctly described as a 'system' because its overall properties (e.g. 'tolerance', 'allergy') emerge from multiple interactions of its components cells. To mobilize a response where needed, the majority of the cells of the system are obligatorily highly motile and so must communicate with one another over both time and space. Here, we discuss the flexibility of the primary immunological synapse (IS) with respect to motility. We then consider the primary IS as an initiating module that licenses 'immunological circuits': the latter consisting of two or more cell-cell synaptic interactions. We discuss how two or three component immunological circuits interact might with one another in sequence and how the timing, stoichiometry, milieu, and duration of assembly of immunological circuits are likely to be key determinants in the emergent outcome and thus the system-wide immune response. An evolving consideration of immunological circuits, with an emphasis on the cell-cell modules that complement T-antigen-presenting cell interaction, provides a fundamental starting point for systems analysis of the immune response.
    MeSH term(s) Animals ; Cell Communication/immunology ; Cell Movement/immunology ; Cellular Microenvironment/immunology ; Cytokinesis/immunology ; Humans ; Immune System ; Immunity, Cellular ; Immunological Synapses/immunology ; Receptor Cross-Talk ; Signal Transduction
    Language English
    Publishing date 2012-12-06
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 391796-4
    ISSN 1600-065X ; 0105-2896
    ISSN (online) 1600-065X
    ISSN 0105-2896
    DOI 10.1111/imr.12021
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: A phosphatidylinositol-3-kinase-dependent signal transition regulates ARF1 and ARF6 during Fcgamma receptor-mediated phagocytosis.

    Beemiller, Peter / Hoppe, Adam D / Swanson, Joel A

    PLoS biology

    2006  Volume 4, Issue 6, Page(s) e162

    Abstract: Fcgamma receptor (FcgammaR)-mediated phagocytosis of IgG-coated particles is regulated by 3'-phosphoinositides (3'PIs) and several classes of small GTPases, including ARF6 from the ADP Ribosylation Factor subfamily. The insensitivity of phagocytosis to ... ...

    Abstract Fcgamma receptor (FcgammaR)-mediated phagocytosis of IgG-coated particles is regulated by 3'-phosphoinositides (3'PIs) and several classes of small GTPases, including ARF6 from the ADP Ribosylation Factor subfamily. The insensitivity of phagocytosis to brefeldin A (BFA), an inhibitor of certain ARF guanine nucleotide exchange factors (GEFs), previously indicated that ARF1 did not participate in phagocytosis. In this study, we show that ARF1 was activated during FcgammaR-mediated phagocytosis and that blocking normal ARF1 cycling inhibited phagosome closure. We examined the distributions and activation patterns of ARF6 and ARF1 during FcgammaR-mediated phagocytosis using fluorescence resonance energy transfer (FRET) stoichiometric microscopy of macrophages expressing CFP- or YFP-chimeras of ARF1, ARF6, and a GTP-ARF-binding protein domain. Both GTPases were activated by BFA-insensitive factors at sites of phagocytosis. ARF6 activation was restricted to the leading edge of the phagocytic cup, while ARF1 activation was delayed and delocalized over the phagosome. Phagocytic cups formed after inhibition of PI 3-kinase (PI-3K) contained persistently activated ARF6 and minimally activated ARF1. This indicates that a PI-3K-dependent signal transition defines the sequence of ARF GTPase activation during phagocytosis and that ARF6 and ARF1 coordinate different functions at the forming phagosome.
    MeSH term(s) ADP-Ribosylation Factor 1/analysis ; ADP-Ribosylation Factor 1/metabolism ; ADP-Ribosylation Factor 6 ; ADP-Ribosylation Factors/analysis ; ADP-Ribosylation Factors/metabolism ; Brefeldin A/pharmacology ; Cells, Cultured ; Enzyme Activation ; Fluorescence Resonance Energy Transfer ; Humans ; Macrophages/metabolism ; Mutation ; Phagocytosis/physiology ; Phosphatidylinositol 3-Kinases/metabolism ; Phosphatidylinositol 3-Kinases/physiology ; Phosphoinositide-3 Kinase Inhibitors ; Receptors, IgG/physiology ; Recombinant Fusion Proteins/metabolism ; Signal Transduction
    Chemical Substances ADP-Ribosylation Factor 6 ; Phosphoinositide-3 Kinase Inhibitors ; Receptors, IgG ; Recombinant Fusion Proteins ; Brefeldin A (20350-15-6) ; ADP-Ribosylation Factor 1 (EC 3.6.5.2) ; ADP-Ribosylation Factors (EC 3.6.5.2) ; ARF6 protein, human (EC 3.6.5.2)
    Language English
    Publishing date 2006-05-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2126776-5
    ISSN 1545-7885 ; 1544-9173
    ISSN (online) 1545-7885
    ISSN 1544-9173
    DOI 10.1371/journal.pbio.0040162
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  8. Article ; Online: Visualizing dynamic microvillar search and stabilization during ligand detection by T cells.

    Cai, En / Marchuk, Kyle / Beemiller, Peter / Beppler, Casey / Rubashkin, Matthew G / Weaver, Valerie M / Gérard, Audrey / Liu, Tsung-Li / Chen, Bi-Chang / Betzig, Eric / Bartumeus, Frederic / Krummel, Matthew F

    Science (New York, N.Y.)

    2017  Volume 356, Issue 6338

    Abstract: During immune surveillance, T cells survey the surface of antigen-presenting cells. In searching for peptide-loaded major histocompatibility complexes (pMHCs), they must solve a classic trade-off between speed and sensitivity. It has long been supposed ... ...

    Abstract During immune surveillance, T cells survey the surface of antigen-presenting cells. In searching for peptide-loaded major histocompatibility complexes (pMHCs), they must solve a classic trade-off between speed and sensitivity. It has long been supposed that microvilli on T cells act as sensory organs to enable search, but their strategy has been unknown. We used lattice light-sheet and quantum dot-enabled synaptic contact mapping microscopy to show that anomalous diffusion and fractal organization of microvilli survey the majority of opposing surfaces within 1 minute. Individual dwell times were long enough to discriminate pMHC half-lives and T cell receptor (TCR) accumulation selectively stabilized microvilli. Stabilization was independent of tyrosine kinase signaling and the actin cytoskeleton, suggesting selection for avid TCR microclusters. This work defines the efficient cellular search process against which ligand detection takes place.
    MeSH term(s) Actin Cytoskeleton/metabolism ; Animals ; Antigens/immunology ; Fractals ; Ligands ; Mice ; Microscopy/methods ; Microvilli/chemistry ; Microvilli/metabolism ; Quantum Dots ; Receptors, Antigen, T-Cell/metabolism ; T-Lymphocytes/cytology ; T-Lymphocytes/immunology ; T-Lymphocytes/metabolism
    Chemical Substances Antigens ; Ligands ; Receptors, Antigen, T-Cell
    Language English
    Publishing date 2017-05-11
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.aal3118
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Real-time analysis of T cell receptors in naive cells in vitro and in vivo reveals flexibility in synapse and signaling dynamics.

    Friedman, Rachel S / Beemiller, Peter / Sorensen, Caitlin M / Jacobelli, Jordan / Krummel, Matthew F

    The Journal of experimental medicine

    2010  Volume 207, Issue 12, Page(s) 2733–2749

    Abstract: The real-time dynamics of the T cell receptor (TCR) reflect antigen detection and T cell signaling, providing valuable insight into the evolving events of the immune response. Despite considerable advances in studying TCR dynamics in simplified systems ... ...

    Abstract The real-time dynamics of the T cell receptor (TCR) reflect antigen detection and T cell signaling, providing valuable insight into the evolving events of the immune response. Despite considerable advances in studying TCR dynamics in simplified systems in vitro, live imaging of subcellular signaling complexes expressed at physiological densities in intact tissues has been challenging. In this study, we generated a transgenic mouse with a TCR fused to green fluorescent protein to provide insight into the early signaling events of the immune response. To enable imaging of TCR dynamics in naive T cells in the lymph node, we enhanced signal detection of the fluorescent TCR fusion protein and used volumetric masking with a second fluorophore to mark the T cells expressing the fluorescent TCR. These in vivo analyses and parallel experiments in vitro show minimal and transient incorporation of TCRs into a stable central supramolecular activating cluster (cSMAC) structure but strong evidence for rapid, antigen-dependent TCR internalization that was not contingent on T cell motility arrest or cSMAC formation. Short-lived antigen-independent TCR clustering was also occasionally observed. These in vivo observations demonstrate that varied TCR trafficking and cell arrest dynamics occur during early T cell activation.
    MeSH term(s) Animals ; Dendritic Cells/physiology ; Fluorescence ; Immunological Synapses/physiology ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; Receptors, Antigen, T-Cell/physiology ; Signal Transduction/physiology
    Chemical Substances Receptors, Antigen, T-Cell
    Language English
    Publishing date 2010-11-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 218343-2
    ISSN 1540-9538 ; 0022-1007
    ISSN (online) 1540-9538
    ISSN 0022-1007
    DOI 10.1084/jem.20091201
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  10. Article ; Online: Secondary T cell-T cell synaptic interactions drive the differentiation of protective CD8+ T cells.

    Gérard, Audrey / Khan, Omar / Beemiller, Peter / Oswald, Erin / Hu, Joyce / Matloubian, Mehrdad / Krummel, Matthew F

    Nature immunology

    2013  Volume 14, Issue 4, Page(s) 356–363

    Abstract: Immunization results in the differentiation of CD8+ T cells, such that they acquire effector abilities and convert into a memory pool. Priming of T cells takes place via an immunological synapse formed with an antigen-presenting cell (APC). By disrupting ...

    Abstract Immunization results in the differentiation of CD8+ T cells, such that they acquire effector abilities and convert into a memory pool. Priming of T cells takes place via an immunological synapse formed with an antigen-presenting cell (APC). By disrupting synaptic stability at different times, we found that the differentiation of CD8+ T cells required cell interactions beyond those made with APCs. We identified a critical differentiation period that required interactions between primed T cells. We found that T cell-T cell synapses had a major role in the generation of protective CD8+ T cell memory. T cell-T cell synapses allowed T cells to polarize critical secretion of interferon-γ (IFN-γ) toward each other. Collective activation and homotypic clustering drove cytokine sharing and acted as regulatory stimuli for T cell differentiation.
    MeSH term(s) Animals ; Antigen-Presenting Cells/immunology ; Antigen-Presenting Cells/metabolism ; CD8-Positive T-Lymphocytes/cytology ; CD8-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/metabolism ; Cell Communication/immunology ; Cell Differentiation/immunology ; Cytokines/immunology ; Cytokines/metabolism ; Immunologic Memory ; Immunological Synapses ; Mice ; Mice, Knockout ; T-Lymphocyte Subsets/cytology ; T-Lymphocyte Subsets/immunology ; T-Lymphocyte Subsets/metabolism
    Chemical Substances Cytokines
    Language English
    Publishing date 2013-03-10
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2016987-5
    ISSN 1529-2916 ; 1529-2908
    ISSN (online) 1529-2916
    ISSN 1529-2908
    DOI 10.1038/ni.2547
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