scholarly journals LFA-1 and Kindlin-3 enable the collaborative transport of SLP-76 microclusters by myosin and dynein motors

2021 ◽  
Author(s):  
Keith P. Eidell ◽  
Alenka Lovy ◽  
Nicholas R. Sylvain ◽  
Frank A. Scangarello ◽  
Hayley I. Muendlein ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Ligand Density ◽  
Immune Synapse ◽  
Dynein Motor ◽  
Myosin Filaments ◽  
Actomyosin Contraction ◽  
Centripetal Movement

Integrin engagement within the immune synapse enhances T cell activation, but our understanding of this process is incomplete. In response to T cell receptor (TCR) ligation, SLP-76 (LCP2), ADAP (FYB), and SKAP-55 (SKAP1) are recruited into microclusters and activate integrins via the effectors Talin-1 and Kindlin-3. We postulated that integrins influence the centripetal transport and signaling of SLP-76 microclusters via these linkages. We show that contractile myosin filaments surround and are co-transported with SLP-76 microclusters, and that TCR ligand density governs the centripetal movement of both structures. Centripetal transport requires formin activity, actomyosin contraction, microtubule integrity, and dynein motor function. Although immobilized VLA-4 (a4b1) and LFA-1 (aLb2) ligands arrest the centripetal movement of SLP-76 microclusters and myosin filaments, VLA-4 acts distally, while LFA-1 acts in the lamellum. Integrin b2, Kindlin-3, and Zyxin are required for complete centripetal transport, while integrin b1 and Talin-1 are not. CD69 upregulation is similarly dependent on integrin b2, Kindlin-3, and Zyxin, but not Talin-1. These findings highlight the integration of cytoskeletal systems within the immune synapse and reveal extracellular ligand-independent roles for LFA-1 and Kindlin-3.

scholarly journals Ca2+/Calmodulin-Dependent Protein Kinase II Is a Modulator of CARMA1-Mediated NF-κB Activation

2006 ◽  
Vol 26 (14) ◽  
pp. 5497-5508 ◽  
Author(s):  
Kazuhiro Ishiguro ◽  
Todd Green ◽  
Joseph Rapley ◽  
Heather Wachtel ◽  
Cosmas Giallourakis ◽  
...  
Keyword(s):  
T Cell ◽  
Protein Kinase ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
Dependent Protein Kinase ◽  
Immune Synapse ◽  
Protein Kinase Ii ◽  
Dependent Protein

ABSTRACT CARMA1 is a central regulator of NF-κB activation in lymphocytes. CARMA1 and Bcl10 functionally interact and control NF-κB signaling downstream of the T-cell receptor (TCR). Computational analysis of expression neighborhoods of CARMA1-Bcl10MALT 1 for enrichment in kinases identified calmodulin-dependent protein kinase II (CaMKII) as an important component of this pathway. Here we report that Ca2+/CaMKII is redistributed to the immune synapse following T-cell activation and that CaMKII is critical for NF-κB activation induced by TCR stimulation. Furthermore, CaMKII enhances CARMA1-induced NF-κB activation. Moreover, we have shown that CaMKII phosphorylates CARMA1 on Ser109 and that the phosphorylation facilitates the interaction between CARMA1 and Bcl10. These results provide a novel function for CaMKII in TCR signaling and CARMA1-induced NF-κB activation.

The costimulatory activity of Tim-3 requires Akt and MAPK signaling and its recruitment to the immune synapse

2021 ◽  
Vol 14 (687) ◽  
pp. eaba0717
Author(s):  
Shunsuke Kataoka ◽  
Priyanka Manandhar ◽  
Judong Lee ◽  
Creg J. Workman ◽  
Hridesh Banerjee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transmembrane Domain ◽  
Transmembrane Protein ◽  
Cell Receptor ◽  
Mapk Signaling ◽  
Inhibitory Protein ◽  
Immune Synapse

Expression of the transmembrane protein Tim-3 is increased on dysregulated T cells undergoing chronic activation, including during chronic infection and in solid tumors. Thus, Tim-3 is generally thought of as an inhibitory protein. We and others previously reported that under some circumstances, Tim-3 exerts paradoxical costimulatory activity in T cells (and other cells), including enhancement of the phosphorylation of ribosomal S6 protein. Here, we examined the upstream signaling pathways that control Tim-3–mediated increases in phosphorylated S6 in T cells. We also defined the localization of Tim-3 relative to the T cell immune synapse and its effects on downstream signaling. Recruitment of Tim-3 to the immune synapse was mediated exclusively by the transmembrane domain, replacement of which impaired the ability of Tim-3 to costimulate T cell receptor (TCR)–dependent S6 phosphorylation. Furthermore, enforced localization of the Tim-3 cytoplasmic domain to the immune synapse in a chimeric antigen receptor still enabled T cell activation. Together, our findings are consistent with a model whereby Tim-3 enhances TCR-proximal signaling under acute conditions.

scholarly journals The Swing of Lipids at Peroxisomes and Endolysosomes in T Cell Activation

2020 ◽  
Vol 21 (8) ◽  
pp. 2859
Author(s):  
Sara G. Dosil ◽  
Amelia Rojas-Gomez ◽  
Francisco Sánchez-Madrid ◽  
Noa B. Martín-Cófreces
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Synapse Formation ◽  
Cell Receptor ◽  
Metabolic Reprogramming ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Immune Synapse ◽  
Antigen Presenting

The immune synapse (IS) is a well-known intercellular communication platform, organized at the interphase between the antigen presenting cell (APC) and the T cell. After T cell receptor (TCR) stimulation, signaling from plasma membrane proteins and lipids is amplified by molecules and downstream pathways for full synapse formation and maintenance. This secondary signaling event relies on intracellular reorganization at the IS, involving the cytoskeleton and components of the secretory/recycling machinery, such as the Golgi apparatus and the endolysosomal system (ELS). T cell activation triggers a metabolic reprogramming that involves the synthesis of lipids, which act as signaling mediators, and an increase of mitochondrial activity. Then, this mitochondrial activity results in elevated reactive oxygen species (ROS) production that may lead to cytotoxicity. The regulation of ROS levels requires the concerted action of mitochondria and peroxisomes. In this review, we analyze this reprogramming and the signaling implications of endolysosomal, mitochondrial, peroxisomal, and lipidic systems in T cell activation.

scholarly journals IFT20 controls LAT recruitment to the immune synapse and T-cell activation in vivo

2015 ◽  
Vol 113 (2) ◽  
pp. 386-391 ◽  
Author(s):  
Omar I. Vivar ◽  
Giulia Masi ◽  
Jean-Marie Carpier ◽  
Joao G. Magalhaes ◽  
Donatella Galgano ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Intraflagellar Transport ◽  
Cell Receptor ◽  
Immune Synapse ◽  
Cell Responses

Biogenesis of the immune synapse at the interface between antigen-presenting cells and T cells assembles and organizes a large number of membrane proteins required for effective signaling through the T-cell receptor. We showed previously that the intraflagellar transport protein 20 (IFT20), a component of the intraflagellar transport system, controls polarized traffic during immune synapse assembly. To investigate the role of IFT20 in primary CD4+ T cells in vitro and in vivo, we generated mice bearing a conditional defect of IFT20 expression in T cells. We show that in the absence of IFT20, although cell spreading and the polarization of the centrosome were unaffected, T-cell receptor (TCR)-mediated signaling and recruitment of the signaling adaptor LAT (linker for activation of T cells) at the immune synapse were reduced. As a consequence, CD4+ T-cell activation and proliferation were also defective. In vivo, conditional IFT20-deficient mice failed to mount effective antigen-specific T-cell responses, and their T cells failed to induce colitis after adoptive transfer to Rag−/− mice. IFT20 is therefore required for the delivery of the intracellular pool of LAT to the immune synapse in naive primary T lymphocytes and for effective T-cell responses in vivo.

scholarly journals Dynein-Driven Transport of T Cell Receptor Microclusters Regulates Immune Synapse Formation and T Cell Activation

Immunity ◽  
2011 ◽  
Vol 34 (6) ◽  
pp. 919-931 ◽  
Author(s):  
Akiko Hashimoto-Tane ◽  
Tadashi Yokosuka ◽  
Kumiko Sakata-Sogawa ◽  
Machie Sakuma ◽  
Chitose Ishihara ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Synapse Formation ◽  
Cell Receptor ◽  
Immune Synapse

scholarly journals PD-1 suppresses TCR-CD8 cooperativity during T-cell antigen recognition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kaitao Li ◽  
Zhou Yuan ◽  
Jintian Lyu ◽  
Eunseon Ahn ◽  
Simon J. Davis ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Clinical Success ◽  
Clinical Intervention ◽  
Cell Receptor ◽  
Cell Interaction ◽  
Antigen Recognition ◽  
Inhibitory Function ◽  
Src Homology

AbstractDespite the clinical success of blocking its interactions, how PD-1 inhibits T-cell activation is incompletely understood, as exemplified by its potency far exceeding what might be predicted from its affinity for PD-1 ligand-1 (PD-L1). This may be partially attributed to PD-1’s targeting the proximal signaling of the T-cell receptor (TCR) and co-stimulatory receptor CD28 via activating Src homology region 2 domain-containing phosphatases (SHPs). Here, we report PD-1 signaling regulates the initial TCR antigen recognition manifested in a smaller spreading area, fewer molecular bonds formed, and shorter bond lifetime of T cell interaction with peptide-major histocompatibility complex (pMHC) in the presence than absence of PD-L1 in a manner dependent on SHPs and Leukocyte C-terminal Src kinase. Our results identify a PD-1 inhibitory mechanism that disrupts the cooperative TCR–pMHC–CD8 trimolecular interaction, which prevents CD8 from augmenting antigen recognition, explaining PD-1’s potent inhibitory function and its value as a target for clinical intervention.

scholarly journals A new HLA-linked T cell membrane molecule, related to the beta chain of the clonotypic receptor, is associated with T3.

1986 ◽  
Vol 164 (2) ◽  
pp. 458-473 ◽  
Author(s):  
Y Bushkin ◽  
D N Posnett ◽  
B Pernis ◽  
C Y Wang
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Functional Role ◽  
Cell Activation ◽  
Cell Receptor ◽  
Leukemia Cells ◽  
Alpha Beta ◽  
Beta 2 Microglobulin ◽  
T Cell Membrane ◽  
Membrane Molecule

The 38 kD molecule is noncovalently associated with beta 2 microglobulin (beta 2m)-free HLA heavy chain-like molecule, and thus forms a second heterodimer distinct from the clonotypic alpha/beta T cell receptor expressed by the same clone of leukemia cells. This second heterodimer (38 kD/HLA) is variably expressed and appears to be associated with the T3 molecule. We suggest, therefore, that it has a functional role in T cell activation.

scholarly journals T cell receptor zeta/CD3-p59fyn(T)-associated p120/130 binds to the SH2 domain of p59fyn(T).

1993 ◽  
Vol 178 (6) ◽  
pp. 2107-2113 ◽  
Author(s):  
A J da Silva ◽  
O Janssen ◽  
C E Rudd
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Intracellular Signaling ◽  
Cell Activation ◽  
Cell Receptor ◽  
Sh2 Domain ◽  
T Complex

Intracellular signaling from the T cell receptor (TCR)zeta/CD3 complex is likely to be mediated by associated protein tyrosine kinases such as p59fyn(T), ZAP-70, and the CD4:p56lck and CD8:p56lck coreceptors. The nature of the signaling cascade initiated by these kinases, their specificities, and downstream targets remain to be elucidated. The TCR-zeta/CD3:p59fyn(T) complex has previously been noted to coprecipitate a 120/130-kD doublet (p120/130). This intracellular protein of unknown identity associates directly with p59fyn(T) within the receptor complex. In this study, we have shown that this interaction with p120/130 is specifically mediated by the SH2 domain (not the fyn-SH3 domain) of p59fyn(T). Further, based on the results of in vitro kinase assays, p120/130 appears to be preferentially associated with p59fyn(T) in T cells, and not with p56lck. Antibody reprecipitation studies identified p120/130 as a previously described 130-kD substrate of pp60v-src whose function and structure is unknown. TCR-zeta/CD3 induced activation of T cells augmented the tyrosine phosphorylation of p120/130 in vivo as detected by antibody and GST:fyn-SH2 fusion proteins. p120/130 represents the first identified p59fyn(T):SH2 binding substrate in T cells, and as such is likely to play a key role in the early events of T cell activation.

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