scholarly journals Phosphoproteomics of CD2 signaling reveals an AMPK-dependent regulation of lytic granule polarization in cytotoxic T cells

2019 ◽  
Author(s):  
Vanessa Zurli ◽  
Tommaso Montecchi ◽  
Raphael Heilig ◽  
Isabel Poschke ◽  
Michael Volkmar ◽  
...  
Keyword(s):  
T Cells ◽  
Cytotoxic T Cells ◽  
Critical Role ◽  
Cell Receptor ◽  
Microtubule Organizing Center ◽  
Lytic Granules ◽  
Cytoskeleton Organization ◽  
Depth Analysis ◽  
Organizing Center ◽  
Insight Into

SummaryThe in-depth analysis of costimulatory signaling enhancing the activity of cytotoxic T cells (CTLs) represents a major approach towards immunotherapy development. Here we report that CD2 costimulation plays a critical role in killing by freshly isolated human CTLs, which represent a challenging but valuable study model to gain insight into CTL biology. We show that CD2 triggering critically aids signaling by the T cell receptor in the formation of functional immune synapses by promoting the polarization of lytic granules towards the microtubule-organizing center (MTOC). To gain insight into the underlying elusive mechanism, we explored the CD2 signaling network by phosphoproteomics, which revealed 616 CD2-regulated phosphorylation events in 373 proteins implicated in the regulation of vesicular trafficking, cytoskeleton organization, autophagy and metabolism. Strikingly, signaling by the master metabolic regulator AMP-activated protein kinase (AMPK) represents a functionally critical node of the CD2 network which regulates granule polarization towards the MTOC in CTLs. Granule trafficking is driven by active AMPK enriched on adjacent lysosomes, illustrating a novel signaling cross-talk between vesicular compartments in CTLs. Our results thus establish CD2 signaling as key for regulating cytotoxic killing and granule polarization in freshly isolated CTLs and strengthens the rationale to choose CD2 and AMPK as therapeutic targets to boost CTL activity.

scholarly journals Phosphoproteomics of CD2 signaling reveals AMPK-dependent regulation of lytic granule polarization in cytotoxic T cells

2020 ◽  
Vol 13 (631) ◽  
pp. eaaz1965 ◽  
Author(s):  
Vanessa Zurli ◽  
Tommaso Montecchi ◽  
Raphael Heilig ◽  
Isabel Poschke ◽  
Michael Volkmar ◽  
...  
Keyword(s):  
T Cells ◽  
Cytotoxic T Cells ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Cell Receptor ◽  
Microtubule Organizing Center ◽  
Lytic Granules ◽  
Organizing Center ◽  
Lytic Granule ◽  
Insight Into

Understanding the costimulatory signaling that enhances the activity of cytotoxic T cells (CTLs) could identify potential targets for immunotherapy. Here, we report that CD2 costimulation plays a critical role in target cell killing by freshly isolated human CD8+ T cells, which represent a challenging but valuable model to gain insight into CTL biology. We found that CD2 stimulation critically enhanced signaling by the T cell receptor in the formation of functional immune synapses by promoting the polarization of lytic granules toward the microtubule-organizing center (MTOC). To gain insight into the underlying mechanism, we explored the CD2 signaling network by phosphoproteomics, which revealed 616 CD2-regulated phosphorylation events in 373 proteins implicated in the regulation of vesicular trafficking, cytoskeletal organization, autophagy, and metabolism. Signaling by the master metabolic regulator AMP-activated protein kinase (AMPK) was a critical node in the CD2 network, which promoted granule polarization toward the MTOC in CD8+ T cells. Granule trafficking was driven by active AMPK enriched on adjacent lysosomes, revealing previously uncharacterized signaling cross-talk between vesicular compartments in CD8+ T cells. Our results thus establish CD2 signaling as key for mediating cytotoxic killing and granule polarization in freshly isolated CD8+ T cells and strengthen the rationale to choose CD2 and AMPK as therapeutic targets to enhance CTL activity.

scholarly journals Engineering CD4+ T Cells to Enhance Cancer Immunity

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1721 ◽  
Author(s):  
Francesca Sillito ◽  
Angelika Holler ◽  
Hans J. Stauss
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
Cd4 T Cells ◽  
Cytotoxic T Cells ◽  
Critical Role ◽  
Cell Receptor ◽  
Convincing Evidence ◽  
Indirect Pathway ◽  
Tumour Immunity

This review presents key advances in combining T cell receptor (TCR) gene transfer to redirect T-cell specificity with gene engineering in order to enhance cancer-protective immune function. We discuss how emerging insights might be applied to CD4+ T cells. Although much attention has been paid to the role of CD8+ cytotoxic T cells in tumour protection, we provide convincing evidence that CD4+ helper T cells play a critical role in cancer immune responses in animal models and also in patients. We demonstrate that genetic engineering technologies provide exciting opportunities to extend the specificity range of CD4+ T cells from MHC class-II-presented epitopes to include peptides presented by MHC class I molecules. Functional enhancement of tumour immunity can improve the sensitivity of T cells to cancer antigens, promote survival in a hostile tumour microenvironment, boost cancer-protective effector mechanisms and enable the formation of T-cell memory. Engineered cancer-specific CD4+ T cells may contribute to protective immunity by a direct pathway involving cancer cell killing, and by an indirect pathway that boosts the function, persistence and memory formation of CD8+ T cells.

scholarly journals The Msd1–Wdr8–Pkl1 complex anchors microtubule minus ends to fission yeast spindle pole bodies

2015 ◽  
Vol 209 (4) ◽  
pp. 549-562 ◽  
Author(s):  
Masashi Yukawa ◽  
Chiho Ikebe ◽  
Takashi Toda
Keyword(s):  
Fission Yeast ◽  
Critical Role ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Microtubule Organizing Center ◽  
Spatiotemporal Regulation ◽  
Spindle Pole Bodies ◽  
Organizing Center ◽  
Spindle Microtubules ◽  
Insight Into

The minus ends of spindle microtubules are anchored to a microtubule-organizing center. The conserved Msd1/SSX2IP proteins are localized to the spindle pole body (SPB) and the centrosome in fission yeast and humans, respectively, and play a critical role in microtubule anchoring. In this paper, we show that fission yeast Msd1 forms a ternary complex with another conserved protein, Wdr8, and the minus end–directed Pkl1/kinesin-14. Individual deletion mutants displayed the identical spindle-protrusion phenotypes. Msd1 and Wdr8 were delivered by Pkl1 to mitotic SPBs, where Pkl1 was tethered through Msd1–Wdr8. The spindle-anchoring defect imposed by msd1/wdr8/pkl1 deletions was suppressed by a mutation of the plus end–directed Cut7/kinesin-5, which was shown to be mutual. Intriguingly, Pkl1 motor activity was not required for its anchoring role once targeted to the SPB. Therefore, spindle anchoring through Msd1–Wdr8–Pkl1 is crucial for balancing the Cut7/kinesin-5–mediated outward force at the SPB. Our analysis provides mechanistic insight into the spatiotemporal regulation of two opposing kinesins to ensure mitotic spindle bipolarity.

scholarly journals CD28-B7 interactions allow the induction of CD8+ cytotoxic T lymphocytes in the absence of exogenous help.

1993 ◽  
Vol 177 (6) ◽  
pp. 1791-1796 ◽  
Author(s):  
F A Harding ◽  
J P Allison
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytotoxic T Cells ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Histocompatibility Complex ◽  
Necessary And Sufficient ◽  
Additional Antigen

The activation requirements for the generation of CD8+ cytotoxic T cells (CTL) are poorly understood. Here we demonstrate that in the absence of exogenous help, a CD28-B7 interaction is necessary and sufficient for generation of class I major histocompatibility complex-specific CTL. Costimulation is required only during the inductive phase of the response, and not during the effector phase. Transfection of the CD28 counter receptor, B7, into nonstimulatory P815 cells confers the ability to elicit P815-specific CTL, and this response can be inhibited by anti-CD28 Fab or by the chimeric B7-binding protein CTLA4Ig. Anti-CD28 monoclonal antibody (mAb) can provide a costimulatory signal to CD8+ T cells when the costimulatory capacity of splenic stimulators is destroyed by chemical fixation. CD28-mediated signaling provokes the release of interleukin 2 (IL-2) from the CD8+ CTL precursors, as anti-CD28 mAb could be substituted for by the addition of IL-2, and an anti-IL-2 mAb can block the generation of anti-CD28-induced CTL. CD4+ cells are not involved in the costimulatory response in the systems examined. We conclude that CD8+ T cell activation requires two signals: an antigen-specific signal mediated by the T cell receptor, and an additional antigen nonspecific signal provided via a CD28-B7 interaction.

scholarly journals Potentiating CD8+ T cell antitumor activity by inhibiting PCSK9 to promote LDLR-mediated TCR recycling and signaling

2021 ◽  
Author(s):  
Juanjuan Yuan ◽  
Ting Cai ◽  
Xiaojun Zheng ◽  
Yangzi Ren ◽  
Jingwen Qi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antitumor Activity ◽  
Metabolic Regulation ◽  
Cholesterol Metabolism ◽  
Critical Role ◽  
Density Lipoprotein ◽  
Cell Receptor ◽  
Suppressive Effect ◽  
Effector Function

AbstractMetabolic regulation has been proven to play a critical role in T cell antitumor immunity. However, cholesterol metabolism as a key component of this regulation remains largely unexplored. Herein, we found that the low-density lipoprotein receptor (LDLR), which has been previously identified as a transporter for cholesterol, plays a pivotal role in regulating CD8+ T cell antitumor activity. Besides the involvement of cholesterol uptake which is mediated by LDLR in T cell priming and clonal expansion, we also found a non-canonical function of LDLR in CD8+ T cells: LDLR interacts with the T-cell receptor (TCR) complex and regulates TCR recycling and signaling, thus facilitating the effector function of cytotoxic T-lymphocytes (CTLs). Furthermore, we found that the tumor microenvironment (TME) downregulates CD8+ T cell LDLR level and TCR signaling via tumor cell-derived proprotein convertase subtilisin/kexin type 9 (PCSK9) which binds to LDLR and prevents the recycling of LDLR and TCR to the plasma membrane thus inhibits the effector function of CTLs. Moreover, genetic deletion or pharmacological inhibition of PCSK9 in tumor cells can enhance the antitumor activity of CD8+ T cells by alleviating the suppressive effect on CD8+ T cells and consequently inhibit tumor progression. While previously established as a hypercholesterolemia target, this study highlights PCSK9/LDLR as a potential target for cancer immunotherapy as well.

scholarly journals Cdc42-interacting protein–4 functionally links actin and microtubule networks at the cytolytic NK cell immunological synapse

2007 ◽  
Vol 204 (10) ◽  
pp. 2305-2320 ◽  
Author(s):  
Pinaki P. Banerjee ◽  
Rahul Pandey ◽  
Rena Zheng ◽  
Megan M. Suhoski ◽  
Linda Monaco-Shawver ◽  
...  
Keyword(s):  
Actin Filament ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Nk Cell ◽  
Filamentous Actin ◽  
Microtubule Organizing Center ◽  
Interacting Protein ◽  
Lytic Granules ◽  
Organizing Center ◽  
Microtubule Networks

An essential function of the immunological synapse (IS) is directed secretion. NK cells are especially adept at this activity, as they direct lytic granules to the synapse for secretion, which enables cytotoxicity and facilitates host defense. This initially requires rearrangement of the actin cytoskeleton and, subsequently, microtubule-dependent trafficking of the lytic granules. As these two steps are sequential, specific linkages between them are likely to serve as critical regulators of cytotoxicity. We studied Cdc42-interacting protein–4 (CIP4), which constitutively interacts with tubulin and microtubules but focuses to the microtubule organizing center (MTOC) after NK cell activation, when it is able to associate with Wiskott-Aldrich syndrome protein (WASp) and the actin filament–rich IS. WASp deficiency, overexpression of CIP4, or parts of CIP4 interfere with this union and block normal CIP4 localization, MTOC polarization to the IS, and cytotoxicity. Reduction of endogenous CIP4 expression using small interfering RNA similarly inhibits MTOC polarization and cytotoxic activity but does not impair actin filament accumulation at the IS, or Cdc42 activation. Thus, CIP4 is an important cytoskeletal adaptor that functions after filamentous actin accumulation and Cdc42 activation to enable MTOC polarization and NK cell cytotoxicity.

scholarly journals A Critical Role for Natural Killer T Cells in Immunosurveillance of Methylcholanthrene-induced Sarcomas

2002 ◽  
Vol 196 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Nadine Y. Crowe ◽  
Mark J. Smyth ◽  
Dale I. Godfrey
Keyword(s):  
T Cells ◽  
T Cell ◽  
Natural Killer ◽  
Critical Role ◽  
Physiological Role ◽  
Cell Receptor ◽  
Interferon Γ ◽  
Tumor Rejection ◽  
Nk T Cells ◽  
Nk T Cell

Natural killer (NK) T cells initiate potent antitumor responses when stimulated by exogenous factors such as interleukin (IL)-12 or α-galactosylceramide (α-GalCer), however, it is not clear whether this reflects a physiological role for these cells in tumor immunity. Through adoptive transfer of NK T cells from wild-type to NK T cell–deficient (T cell receptor [TCR] Jα281−/−) mice, we demonstrate a critical role for NK T cells in immunosurveillance of methylcholanthrene (MCA)-induced fibrosarcomas, in the absence of exogenous stimulatory factors. Using the same approach with gene-targeted and/or antibody-depleted donor or recipient mice, we have shown that this effect depends on CD1d recognition and requires the additional involvement of both NK and CD8+ T cells. Interferon-γ production by both NK T cells and downstream, non-NK T cells, is essential for protection, and perforin production by effector cells, but not NK T cells, is also critical. The protective mechanisms in this more physiologically relevant system are distinct from those associated with α-GalCer–induced, NK T cell–mediated, tumor rejection. This study demonstrates that, in addition to their importance in tumor immunotherapy induced by IL-12 or α-GalCer, NK T cells can play a critical role in tumor immunosurveillance, at least against MCA-induced sarcomas, in the absence of exogenous stimulation.

Expression of T Cell Receptor γ-Chain in Murine Cytotoxic T Cells: Analysis of a Highly Transcribed Nonrearranged Gene Cluster

Pathobiology ◽  
1988 ◽  
Vol 56 (4) ◽  
pp. 181-189
Author(s):  
Manfred Schulz ◽  
Gabi Lienhard ◽  
Fabio Rupp ◽  
Rolf M. Zinkernagel ◽  
Hans Hengartner
Keyword(s):  
T Cells ◽  
T Cell ◽  
Gene Cluster ◽  
T Cell Receptor ◽  
Cytotoxic T Cells ◽  
Cell Receptor
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