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

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.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1513601113 ◽

2015 ◽

Vol 113 (2) ◽

pp. 386-391 ◽

Cited By ~ 29

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.

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Disc Large Homolog 1 Is Critical for Early T Cell Receptor Micro Cluster Formation and Activation in Human T Cells

Vaccines ◽

10.3390/vaccines9121446 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1446

Author(s):

June Guha ◽

Raj Chari

Keyword(s):

T Cells ◽

T Cell ◽

Cell Signaling ◽

T Cell Receptor ◽

T Cell Activation ◽

Cell Activation ◽

Synapse Formation ◽

Immunological Synapse ◽

Cell Receptor ◽

T Cell Signaling

T cell activation by antigen involves multiple sequential steps, including T cell receptor-microcluster TCR-(MC) formation, immunological synapse formation, and phosphorylation of mediators downstream of the TCR. The adaptor protein, Disc Large Homolog 1 (DLG1), is known to regulate proximal TCR signaling and, in turn, T cell activation, acting as a molecular chaperone that organizes specific kinases downstream of antigen recognition. In this study, we used knockdown and knockout technologies in human primary T cells and a human T cell line to demonstrate the role of DLG1 in proximal T cell signaling. High-end confocal microscopy was used for pictorial representation of T cell micro-clusters and colocalization studies. From all these studies, we could demonstrate that DLG1 functions even earlier than immunological synapse formation, to regulate T cell activation by promoting TCR-MC formation. Moreover, we found that DLG1 can act as a bridge between the TCR-ζ chain and ZAP70 while inhibiting binding of the phosphatase SHP1 to TCR-ζ. Together, these effects drive dysregulation of T cell activation in DLG1-deficient T cells. Overall, the activation and survival status of T cell is a critical determinant of effective vaccine response, and DLG1-mediated T cell signaling events can be a driving factor for improving vaccine-designing strategies.

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Faculty Opinions recommendation of Expansion of the antigenic repertoire of a single T cell receptor upon T cell activation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1000329.5451 ◽

2001 ◽

Author(s):

David Serreze

Keyword(s):

T Cell ◽

T Cell Receptor ◽

T Cell Activation ◽

Cell Activation ◽

Cell Receptor

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Faculty Opinions recommendation of Rab6-dependent retrograde traffic of LAT controls immune synapse formation and T cell activation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732665185.793544400 ◽

2018 ◽

Author(s):

Cosima Tatiana Baldari

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Synapse Formation ◽

Immune Synapse ◽

Retrograde Traffic

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

Molecular and Cellular Biology ◽

10.1128/mcb.02469-05 ◽

2006 ◽

Vol 26 (14) ◽

pp. 5497-5508 ◽

Cited By ~ 72

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.

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

Journal of Experimental Medicine ◽

10.1084/jem.178.6.2107 ◽

1993 ◽

Vol 178 (6) ◽

pp. 2107-2113 ◽

Cited By ~ 46

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

Science Signaling ◽

10.1126/scisignal.aba0717 ◽

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.

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Retrograde And Anterograde Transport Of LAT-Vesicles During The Immunological Synapse Formation: Defining The Finely-Tuned Mechanism

10.1101/2020.12.17.423267 ◽

2020 ◽

Author(s):

Juan José Saez ◽

Stéphanie Dogniaux ◽

Massiullah Shafaq-Zadah ◽

Ludger Johannes ◽

Claire Hivroz ◽

...

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Synapse Formation ◽

Immunological Synapse ◽

Retrograde Transport ◽

Anterograde Transport ◽

Immune Synapse ◽

Cellular Context ◽

Intracellular Compartments

ABSTRACTLAT is an important player of the signaling cascade induced by TCR activation. This adapter molecule is present at the plasma membrane of T lymphocytes and more abundantly in intracellular compartments. Upon T-cell activation the intracellular pool of LAT is recruited to the immune synapse (IS). We previously described two pathways controlling LAT trafficking: retrograde transport from endosomes to the TGN, and anterograde traffic from the Golgi to the IS. We address the specific role of 4 proteins, the GTPase Rab6, the t-SNARE syntaxin-16, the v-SNARE VAMP7 and the golgin GMAP210, in each pathway. Using different methods (endocytosis and Golgi trap assays, confocal and TIRF microscopy, TCR-signalosome pull down) we show that syntaxin-16 is regulating the retrograde transport of LAT whereas VAMP7 is regulating the anterograde transport. Moreover, GMAP210 and Rab6, known to contribute in both pathways, are in our cellular context specifically and respectively involved in anterograde and retrograde transport of LAT. Altogether, our data describe how retrograde and anterograde pathways coordinate LAT enrichment at the IS and point the Golgi as a central hub for the polarized recruitment of LAT to the IS. The role that this finely-tuned transport of signaling molecules plays in T-cell activation is discussed.

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A homodimeric aptamer variant generated from ligand-guided selection activates T-cell receptor cluster of differentiation three complex

10.1101/2020.05.18.102145 ◽

2020 ◽

Author(s):

Lina Freage ◽

Deana Jamal ◽

Nicole Williams ◽

Prabodhika R. Mallikaratchy

Keyword(s):

T Cell ◽

Nucleic Acid ◽

T Cell Receptor ◽

T Cell Activation ◽

Cell Activation ◽

Cell Receptor ◽

Receptor Cluster ◽

Pharmacokinetic Properties ◽

Activation Potential ◽

Cluster Of Differentiation

AbstractRecently, immunotherapeutic modalities with engineered cells and monoclonal antibodies have been effective in treating several malignancies. However, growing evidence suggests that immune-related adverse events (irAE) lead to severe and long-term side effects. Most iRAEs involve prolonged circulation of antibodies. To address this problem, nucleic acid aptamers can serve as alternative molecules to design immunotherapeutics with high functional diversity and predictable circulation times. Here, we report the first synthetic prototype consisting of DNA aptamers, which can activate T-cell receptor cluster of differentiation 3 (TCR-CD3) complex in cultured T-cells. We show that activation potential is similar to that of a monoclonal antibody (mAb) against TCR-CD3, suggesting the potential of aptamers in developing efficacious synthetic immunomodulators. The synthetic prototype of anti-TCR-CD3ε, as described herein, was designed using aptamer ZUCH-1 against TCR-CD3ε, generated by Ligand Guided Selection (LIGS). Aptamer ZUCH-1 was truncated and modified with nuclease-resistant RNA analogs to enhance stability. Several dimeric analogs with truncated and modified variants were designed with variable linker lengths to investigate the activation potential of each construct. Among them, dimeric aptamer with approximate dimensions similar to those of an antibody showed the highest T-cell-activation, suggesting the importance of optimizing linker lengths in engineering functional aptamers. The observed activation potential of dimeric aptamers shows the vast potential of aptamers in designing synthetically versatile immunomodulators with tunable pharmacokinetic properties, expanding immunotherapeutic designs with the use of nucleic acid-based ligands such as aptamers.

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