Release of serine/threonine-phosphorylated adaptors from signaling microclusters down-regulates T cell activation

Lasserre, Rémi; Cuche, Céline; Blecher‐Gonen, Ronnie; Libman, Evgeny; Biquand, Élise; Danckært, Anne; Yablonski, Deborah; Alcover, Andrés; Bartolo, Vincenzo Di

doi:10.1084/jem20813oia36

Cited by 15 publications

(24 citation statements)

References 25 publications

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“…Confocal microscopy of adherent cells showed that both molecules were enriched at the lamellipodium where HPK1 also colocalized with actin. Similar to HPK1 [45][46][47] and negatively regulates T-cell adhesion and spreading on immobilized ICAM-1/Fc under static conditions. 25 Similar effects were reported when HPK1 was knocked down in WEHI 231 cells.…”

Section: Discussionmentioning

confidence: 96%

Hematopoietic progenitor kinase 1 (HPK1) is required for LFA-1–mediated neutrophil recruitment during the acute inflammatory response

Jakob

Pick

Brechtefeld

et al. 2013

Blood

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Key Points• Hematopoietic progenitor kinase 1 (HPK1) regulates LFA-1 affinity and thereby controls adhesion and postadhesion functions of neutrophils.• Hematopoietic progenitor kinase 1 (HPK1) is critically involved in neutrophil trafficking during acute inflammation.Recruitment of polymorphonuclear neutrophils (PMNs) to sites of acute inflammation critically depends on b 2 integrins (CD11/CD18). Recently, the mammalian actin-binding protein 1 (mAbp1) was identified as an important adaptor protein regulating PMN trafficking downstream of b 2 integrins. Here, we show that mAbp1 constitutively co-immunoprecipitated with hematopoietic progenitor kinase 1 (HPK1) in neutrophillike differentiated HL-60 (dHL-60) cells. HPK1 was enriched at the lamellipodium of polarized dHL-60 cells, where it colocalized with mAbp1 and actin. Functional analysis of PMNs from HPK1-deficient mice showed that HPK1 was critical for CXCL1-induced lymphocyte function-associated antigen 1 (LFA-1)-mediated PMN adhesion to ICAM-1 under flow conditions. Accordingly, CXCL1-mediated induction of high-affinity LFA-1 required HPK1, but macrophage antigen 1 (Mac-1) affinity regulation was independent of HPK1. Intravital microscopy of the mouse cremaster muscle confirmed the defect of CXCL1-induced leukocyte adhesion in HPK1-deficient mice. Furthermore, b 2 integrin-mediated post-adhesion processes-adhesion strengthening, spreading, and directed mechanotactic crawling of PMNs under flow conditions-involved HPK1 in vitro and in vivo. Upon intrascrotal administration of tumor necrosis factor a (TNF-a), PMN adhesion and extravasation were severely compromised in HPK1-deficient mice. In summary, our results indicate that HPK1 is critically involved in LFA-1-mediated PMN trafficking during acute inflammation. (Blood. 2013;121(20):4184-4194)

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Section: Discussionmentioning

confidence: 96%

Hematopoietic progenitor kinase 1 (HPK1) is required for LFA-1–mediated neutrophil recruitment during the acute inflammatory response

Jakob

Pick

Brechtefeld

et al. 2013

Blood

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“…Upon association, it was shown that HPK1 phosphorylates SLP-76, leading to a reduction of SLP-76 microclusters (49). Occupancy of the SLP-76 SH2 domain by ADAP would block interactions with HPK1 and prevent microcluster disassembly.…”

Section: Discussionmentioning

confidence: 99%

Multipoint Binding of the SLP-76 SH2 Domain to ADAP Is Critical for Oligomerization of SLP-76 Signaling Complexes in Stimulated T Cells

Coussens

Hayashi

Brown

et al. 2013

Molecular and Cellular Biology

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The adapter molecules SLP-76 and LAT play central roles in T cell activation by recruiting enzymes and other adapters into multiprotein complexes that coordinate highly regulated signal transduction pathways. While many of the associated proteins have been characterized, less is known concerning the mechanisms of assembly for these dynamic and potentially heterogeneous signaling complexes. Engagement of a T cell antigen receptor (TCR) by a cognate peptide-major histocompatibility complex (MHC) on an antigen-presenting cell triggers complex molecular cascades that control signaling pathways crucial for gene transcription, cytokine production, cell adhesion, mobility, proliferation, and differentiation (1). Appropriate T cell responses depend on the formation of multiprotein complexes at the plasma membrane that regulate efficient signal transduction via multiple pathways. TCR stimulation facilitates phosphorylation of the TCR chains by the Src family kinase Lck, which allows for the recruitment and activation of the protein tyrosine kinase Zap-70. Phosphorylation of the essential adapter proteins LAT and SLP-76 by Zap-70 creates docking sites for SH2 domain-containing adapter and effector proteins. The adapter, Grb2, binds LAT and recruits the guanine exchange factor, Sos, while the Grb2-related adapter, Gads, recruits the adapter SLP-76 (1). LAT and SLP-76 recruit other signaling proteins, thereby inducing the assembly of multiprotein complexes. Molecular associations within the multiprotein complexes are dynamic and highly cooperative, which might allow tight regulation of signal transduction pathways in T cells (2-5, 9, 32).In confocal imaging studies of T cell lines and peripheral blood lymphocytes stimulated on anti-CD3-coated glass coverslips, within seconds of TCR engagement LAT and SLP-76 are visualized in microclusters, which contain many protein complexes (6, 7). Numerous reports indicate that effective TCR signaling depends on the assembly and persistence of the microclusters that contain . Microclusters containing LAT are abolished by tyrosine-to-phenylalanine (Y-F) changes of critical Gads and Grb2 binding sites on LAT (8,9,14). Microclusters containing SLP-76 are abolished by a mutation to the Gads binding motif of SLP-76, which prevents recruitment to LAT. In both cases, losses of microclusters are associated with defective signaling. A mutation of the C-terminal SH2 domain of SLP-76 also resulted in a similar loss of SLP-76 microclusters along with severely reduced CD69 upregulation and NFAT activity (8). This result was completely unanticipated, because the mutation is not expected to prevent recruitment to LAT. Instead, the result indicated that the SH2 domain plays a central and essential role in the stabilization of SLP-76 microclusters and signal transduction in T cells.The adapter protein, ADAP, binds the SLP-76 SH2 domain, and the interaction appears to affect TCR signaling (15, 16). SLP-76-deficient J14 cells transfected with SLP-76 containing an SH2 mutation (SLP-76-SH2*) showed reduced ...

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“…Early upon TCR activation, the centrosome localizes to the IS and rapidly polymerizes α/β tubulin dimers in microtubules [18], which organize a profuse network of microtubules at the T cell-APC contact area [18,20]. This dynamic network, regulated by microtubuleassociated proteins (MAPs) and tubulin post-translational modifications (PTMs; Box 1), provides a platform for intracellular transport and integration of the actin and tubulin cytoskeletons [19].…”

Section: The Centrosome Marks the Waymentioning

confidence: 99%

“…Centrosome or microtubule-organizing centre (MTOC; Glossary) localization determines this initial polarity during development, establishing the site of Golgi localization and the trafficking of vesicles and mitochondria [16]. These events are paralleled in T cells as early analysis of T cell activation established the direct involvement of the centrosome in the localization of the Golgi apparatus (GA) at the IS (Figure 1) [5,7,8,[17][18][19].Early upon TCR activation, the centrosome localizes to the IS and rapidly polymerizes α/β tubulin dimers in microtubules [18], which organize a profuse network of microtubules at the T cell-APC contact area [18,20]. This dynamic network, regulated by microtubuleassociated proteins (MAPs) and tubulin post-translational modifications (PTMs; Box 1), provides a platform for intracellular transport and integration of the actin and tubulin cytoskeletons [19].…”

mentioning

confidence: 94%

Immune synapse: conductor of orchestrated organelle movement

Martín-Cófreces¹,

Baixauli²,

Sánchez-Madrid³

2014

Trends in Cell Biology

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SummaryTo ensure proper cell function, intracellular organelles are not randomly distributed within the cell, but polarized and highly constrained by the cytoskeleton and associated adaptor proteins. This relationship between distribution and function was originally found in neurons and epithelial cells; however, recent evidence suggests that it is a more general phenomenon that occurs in many highly specialized cells including the immune T cells. Recent studies reveal that the orchestrated redistribution of organelles is dependent on antigen specific activation and immune-synapse formation of T cells. This review highlights the functional implications of organelle polarization in early T cell activation and examines recent findings on how the immune synapse sets the rhythm of organelle motion and the spread of the activation signal to the nucleus. KeywordsImmune synapse; microcluster; signalosome; mitochondria; vesicle; microtubule Overview of the immune synapseT cell activation starts with an initial wave of signalling that depends on the activation of surface receptors, but subsequent propagation of the signal appears to depend on intracellular compartments, in a sequence driven by the actin and tubulin cytoskeletons [1]. The study of neural synapses highlighted the importance of cell polarity and the specific localization of organelles and clusters of receptors at the pre-and post-synaptic terminals. Despite its transient nature, recent evidence shows that the immune synapse (IS) shares these same neuronal features.The IS is the interface between a T lymphocyte and an antigen presenting cell (APC). During the formation and stabilization of the IS, membrane microdomains and the cytoskeleton reorganize and promote the segregation of membrane and intracellular signaling proteins within the T cell, such as the T cell receptor (TCR), integrins, tyrosine Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts kinases and scaffold proteins such as Linker for activation of T cells (LAT) (Figure 1 and Glossary). The TCR and associated molecules (TCR signalosomes) form microclusters that move to congregate in the central area (central supramolecular activation cluster; cSMAC) of the IS, whereas adhesion receptors such as integrins reorganize in a surrounding external ring called the peripheral or pSMAC ( Figure 2) [2]. In addition, phosphorylation and dephosphorylation, protein-protein interactions and degradation of important molecules such as the TCR-accompanying CD3 complex, tyrosine kinases, phosphatases and adaptor molecules also control receptor activation [3,4]. The polarization of several organelles occurs during T cell stimulation with important roles, such as the centrosome, Golgi apparatus, mitochondria, endoplasmic reticulum and the multivesicular bodies (MVB) [5][6][7][8][9][10]. These rearrangements at the IS promote the activation of signaling pathways that propagate to the nucleus. Signals activating nuclear transcription factors in combination with polarity proteins, such as partit...

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Release of serine/threonine-phosphorylated adaptors from signaling microclusters down-regulates T cell activation

Cited by 15 publications

References 25 publications

Hematopoietic progenitor kinase 1 (HPK1) is required for LFA-1–mediated neutrophil recruitment during the acute inflammatory response

Hematopoietic progenitor kinase 1 (HPK1) is required for LFA-1–mediated neutrophil recruitment during the acute inflammatory response

Multipoint Binding of the SLP-76 SH2 Domain to ADAP Is Critical for Oligomerization of SLP-76 Signaling Complexes in Stimulated T Cells

Immune synapse: conductor of orchestrated organelle movement

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