CC-122 Repairs T Cell Activation in Chronic Lymphocytic Leukemia That Results in a Concomitant Increase in PD-1:PD-L1 and CTLA-4 Immune Checkpoint Expression at the Immunological Synapse

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1738-1738
Author(s):  
Benedetta Apollonio ◽  
Mariam Fanous ◽  
Mohamed-Reda Benmebarek ◽  
Stephen Devereux ◽  
Patrick Hagner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Lymphocytic Leukemia ◽  
Immune Synapse ◽  
Cell Synapse

Abstract Immunomodulatory drugs (IMiDs®) such as lenalidomide and immune checkpoint blockade (ICB) antibodies can enhance autologous anti-tumor T cell immunity and have the potential to elicit durable control of disease in B cell malignancies. These immunotherapies are likely to be most effective when employed in treatment combinations. Thus, the goal of pre-clinical research should be to reveal mechanisms of action (MOA) in the tumor microenvironment (TME) and identify biomarkers to guide development of combination therapy for patients. CC-122 is a novel first-in-class pleiotropic pathway modifier (PPM®) that has potent anti-proliferative, anti-angiogenic and immunomodulatory activities and is currently in Phase I clinical trials for lymphoma and chronic lymphocytic leukemia (CLL). Here, we have utilized the immunological synapse bioassay to examine T cell interactions with CLL tumor cells (modeling anti-tumor T cell responses in the TME) following CC-122 treatment and measure the expression of co-signaling complexes at the synapse. Conjugation assays and confocal imaging were used to visualize intercellular conjugate interactions and F-actin polymerization at the immune synapse between CD4+ and CD8+ T cells and autologous CLL tumor cells pulsed with superantigen (acting as antigen-presenting cells, APCs). Peripheral blood was obtained from treatment naive CLL patients (n=40) representative of disease heterogeneity. Treatment of both purified CLL cells and CD4+ or CD8+ T cells with CC-122 (0.01 - 1 μM for 24h) dramatically enhanced the number of T cells recognizing tumor cells (% conjugation) and increased the formation of F-actin immune synapses (area, μm2) compared to vehicle treated cells (P<.01). Notably, CC-122 treatment induced T cells to engage in multiple tumor cell synapse interactions that were more pronounced in restored CD8+ T cell lytic synapses. This immunomodulatory activity was detected across all CLL patient samples and drug concentrations tested. In addition, synapse strength as measured by total fluorescence intensity of F-actin per T cell:APC conjugate increased significantly with CC-122 (P<.01). A critical MOA of lenalidomide is activation of T cell immune synapse signaling. Here, our comparative studies revealed that CC-122 (0.1 - 1 μM) significantly enhanced autologous T cell synapse activity in CLL by 4 - 5 fold versus vehicle (P<.01), whereas lenalidomide (1 μM) enhanced activity by 3 fold vs vehicle. Moreover, CC-122 treatment resulted in increased expression and polarization of tyrosine-phosphorylated proteins at T cell synapses compared to lenalidomide and vehicle treatment (P<.01). This data provides evidence that CC-122 induces functional T cell synapses that control the assembly of signaling complexes between the T cell receptor (TCR) and the F-actin cytoskeletal layer. Following T cell recognition of APCs, co-signaling receptors co-localize at the immune synapse where they synergize with TCR signaling to promote (co-stimulatory receptors) or inhibit (co-inhibitory/'immune checkpoint' receptors) T cell activation. Quantitative image analysis studies revealed that restoration of T cell synapse activity with CC-122 was accompanied by an increased recruitment of inducible co-stimulator (ICOS) to the synapse that was dose-dependent (P<.01). CC-122 treatment also increased polarized expression of CTLA-4 and PD-1 immune checkpoint proteins at the synapse with PD-L1+ tumor cells. The observed up-regulation of co-inhibitory receptors led to combining CC-122 with anti-PD-L1, anti-PD-1 or anti-CTLA-4 blocking antibodies. Results show that these treatment combinations increased T cell synapse activity compared to using these immunotherapies alone (P<.01). In conclusion, our results demonstrate for the first time that CC-122 can activate T cell immune synapse signaling against autologous CLL tumor cells and this immunomodulatory capability is more potent than lenalidomide. We further show that CC-122 activation of T cells is associated with enhanced expression of the co-stimulatory receptor ICOS and co-inhibitory checkpoints CTLA-4 and PD-1 at the synapse site. Importantly, our pre-clinical data demonstrates that this regulatory feedback inhibition can be exploited by the addition of anti-PD-L1, anti-PD-1 or anti-CTLA-4 ICB to CC-122 to more optimally stimulate T cell activity against immunosuppressive tumor cells. Disclosures Hagner: Celgene: Employment, Equity Ownership. Pourdehnad:Celgene: Employment. Gandhi:Celgene: Employment, Equity Ownership. Ramsay:MedImmune: Research Funding; Celgene: Research Funding.

scholarly journals Periodic Membrane Potential and Ca2+ Oscillations in T Cells Forming an Immune Synapse

2020 ◽  
Vol 21 (5) ◽  
pp. 1568 ◽  
Author(s):  
Ferenc Papp ◽  
Peter Hajdu ◽  
Gabor Tajti ◽  
Agnes Toth ◽  
Eva Nagy ◽  
...  
Keyword(s):  
T Cells ◽  
Membrane Potential ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Calcium Release ◽  
Immunological Synapse ◽  
Level Control ◽  
Potential Oscillations ◽  
Immune Synapse

The immunological synapse (IS) is a specialized contact area formed between a T cell and an antigen presenting cell (APC). Besides molecules directly involved in antigen recognition such as the TCR/CD3 complex, ion channels important in the membrane potential and intracellular free Ca2+ concentration control of T cells are also recruited into the IS. These are the voltage-gated Kv1.3 and Ca2+-activated KCa3.1 K+ channels and the calcium release-activated Ca2+ channel (CRAC). However, the consequence of this recruitment on membrane potential and Ca2+ level control is not known. Here we demonstrate that the membrane potential (MP) of murine T cells conjugated with APCs in an IS shows characteristic oscillations. We found that depolarization of the membrane by current injection or by increased extracellular K+ concentration produced membrane potential oscillations (MPO) significantly more frequently in conjugated T cells than in lone T cells. Furthermore, oscillation of the free intracellular Ca2+ concentration could also be observed more frequently in cells forming an IS than in lone cells. We suggest that in the IS the special arrangement of channels and the constrained space between the interacting cells creates a favorable environment for these oscillations, which may enhance the signaling process leading to T cell activation.

Functional Screening Studies Identify Combinational Activity of PD-L1 and CD200 In Mediating Dysfunctional T Cell Immunological Synapse Formation In Chronic Lymphocytic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 696-696
Author(s):  
Alan G. Ramsay ◽  
Andrew James Clear ◽  
Alexander Davenport ◽  
Rewas Fatah ◽  
John G. Gribben
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Immune Suppression ◽  
Neutralizing Antibodies ◽  
Synapse Formation ◽  
Ex Vivo ◽  
Lymphocytic Leukemia ◽  
Immune Synapse ◽  
Cell Synapse

Abstract Abstract 696 The ability of cancer cells to modulate the immune microenvironment is now recognized as an important hallmark of disease pathophysiology. Identifying the molecular mechanisms of cancer immune suppression in the laboratory is key to the design of more effective immunotherapeutic treatment strategies. We previously demonstrated that chronic lymphocytic leukemia (CLL) cells induce alterations in global gene expression profiles in patient CD4 and CD8 T cells, and a profound T cell immunological synapse formation defect that can be reversed with lenalidomide (J Clin Invest. 2005;115(7):1797-1805, and 2008;118(7):2427-2437). Here we used small interfering RNA (siRNA) with a 2-part functional screen to identify key CLL cell molecules inducing T cell immune suppression. siRNA treated tumor cells were cocultured in direct contact with healthy allogeneic T cells for 24 hours, T cells purified from coculture and used in cell conjugation immune synapse assays with superantigen-pulsed third party B cells as antigen-presenting cells (APCs). Confocal microscopy and image analysis software was used to quantify the mean area of T cell F-actin immune synapse formation events from each experimental cell population. Treatment of the CLL cell line MEC-1 with either TNFα, TGFβ, IL-10, or IL-6 siRNA identified no gain in subsequent CD3 T cell immune synapse function compared to control non-targeting siRNA or untreated CLL cells. However, CD200 or programmed death 1 (PD1) ligand 1 (PD-L1, CD274) siRNA treatment significantly enhanced (P < .01) subsequent T cell synapse formation events with APCs (comparable to positive control experiments blocking tumor cell:T cell direct contact with ICAM-1 siRNA, or primary coculture of T cells with allogeneic healthy donor B cells). Primary CLL patient cells (n=10) were treated with individual or pooled neutralizing antibodies, or siRNA, targeting PD-L1, CD200, or cytokines. This analysis revealed that counteracting the combined activity of PD-L1, CD200 and TGFβ exhibited the most pronounced repair of subsequent T cell synapse function compared to control treated tumor cells (P < .01). These data suggest that CLL-released cytokines such as TGFβ contribute to, but are not essential for the T cell synapse defect. We also identified that blocking the T cell receptors PD-1, CD200-R and TGFβ-R1 with neutralizing antibodies prevents CLL inhibitory signaling (P < .01) compared to isotype control IgG treated T cells in contact with tumor cells. We further show that knock-down of PD-L1, CD200 and TGFβ on ex vivo CLL cells prevents inhibitory CD4 and CD8 T cell synapse function compared to control siRNA (P < .01) using the Eμ-TCL1 mouse model of CLL. The addition of lenalidomide (1μM) in ex vivo CLL cell:T cell coculture assays significantly increased (P < .01) subsequent T cell synapse function compared to untreated vehicle control experiments. Flow cytometric analysis identified that lenalidomide down-regulates both CLL expressed PD-L1 and CD200 ligands, and T cell cognate receptor PD1 and CD200R expression during intercellular contact interactions. Moreover, subsequent effector T cell killing function was significantly enhanced (P < .05) following antibody blockade of CLL cell PD-L1 and CD200 with or without lenalidomide treatment during primary coculture with CD8 T cells. We are currently investigating the expression and activity of PD-L1, CD200, and other co-inhibitory molecules in CLL and other haematological and solid malignancies, using patient tissue microarray analysis and confocal co-localization analysis. This work is identifying common inhibitory ligands utilized by tumor cells to suppress T cell synapse function. These results provide important mechanistic insight into immune suppression in CLL and the action of lenalidomide, and identify co-inhibitory ligands as potential immunotherapeutic targets to repair T cell function. Disclosures: Gribben: Roche: Consultancy; Celgene: Consultancy; GSK: Honoraria; Napp: Honoraria.

A Mouse Model for Immunotherapeutic Reversal of Leukemia-Induced T Cell Dysfunction

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 30-30
Author(s):  
Alan G. Ramsay ◽  
Gullu Gorgun ◽  
Tobias A.W. Holderried ◽  
David Zahrieh ◽  
Fenglong Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Immune Synapse ◽  
Immunological Recognition

Abstract Understanding the elusive mechanisms of tumor-driven immune evasion will aid the refinement of existing cancer immunotherapy strategies and identify novel treatments. To date, pre-clinical animal models that closely model human cancer, including the immune suppressive mechanisms utilized by cancer cells, have been under-characterized. The identification and use of such models should allow better predictions of successful human responses to immunotherapy. As a model for changes induced in non-malignant cells by cancer, we examined T cell function in Eμ-TCL1 transgenic mice as they developed leukemia from 12-months of age. Transgenic expression of TCL1 in B cells had no demonstrable effect on T cells, however, mice with leukemia had decreased in vivo antigen specific T cell activation, suppressed T cell mitogenic proliferation and impaired induction of idiotype specific CD8 T cells capable of killing CLL cells compared to control WT mice (age-matched throughout study) or Eμ-TCL1 transgenic mice without CLL. Leukemic mice also had dysfunctional T cell lymphokine production (Th2-preponderant). To understand the molecular basis for the observed functional defects and to compare changes seen in mice and patients with CLL we performed gene expression profiling. Analysis of highly purified CD4 and CD8 T cells in CLL mice demonstrated altered gene expression profiles compared to WT mice or to young Eμ-TCL1 mice without disease. Of note, infusion of CLL cells into young Eμ-TCL1 mice induced gene expression changes comparable to those seen in mice with developed leukemia, demonstrating a causal relationship between leukemia and the T cell defects. Analysis of gene expression changes in T cells in CLL mice compared with those in patients was performed using RESOURCERER, a database for annotating and linking microarray resources within and across species and identified 50 overlapping genes in CD4 T cells and 45 overlapping genes in CD8 T cells. The majority of differentially expressed genes in CD4 T cells from both mice and patients with CLL were involved in cell proliferation and activation pathways with increase in Lck. Multiple defects within the actin cytoskeletal formation pathways were identified in both CD4 and CD8 T cells including Cdc42. Integrity of the T cell cytoskeleton is essential to regulate the dynamic signaling required for T cell activation and effector function in response to immunological recognition of antigen-presenting cells (APCs). T cell conjugates from mice with leukemia had suppressed antigen-dependent F-actin accumulation and early T cell signaling at the immune synapse with CLL cells (APCs) compared to WT mice conjugates. Moreover, we have demonstrated that infusion of CLL cells into young mice induces this T cell defect, demonstrating an in vivo immunomodulating mechanism utilized by tumor cells. Treatment of both CLL cells and autologous T cells from leukemic mice with lenalidomide (0.5 μM for 24 h) enhanced the formation of the F-actin immune synapse and recruitment of tyrosine-phosphorylated proteins irrespective of the presence of exogenous antigen. Of note, the capacity to repair immunological recognition with this agent was associated with increased recruitment of the cytoskeletal signaling molecules Lck and Cdc42 to the immunological synapse, regardless of whether the gene was increased or decreased on gene expression profiling. These results demonstrate that leukemia cells induce changes in multiple T cell pathways regulating antigen recognition and effector function. The similarities with human CLL including reversible immunological synapse dysfunction with an immunomodulating drug validates the use of Eμ-TCL1 mice as a model for further analyses of ways to prevent and reverse cancer-induced immune dysfunction. The use of this model to understand and reverse the molecular changes in T cells induced by leukemia will likely have broad applications to maximize immune responses in patients.

Intermediate Filament (IF) Protein Vimentin Regulates T Cell Mediated Immune Response in Gvhd

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3073-3073 ◽  
Author(s):  
Dan Li ◽  
Patenia Rebecca ◽  
Miguel A. Cruz ◽  
Jeffrey J. Molldrem ◽  
Richard E. Champlin ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Synapse Formation ◽  
Immunological Synapse ◽  
Immune Synapse ◽  
T Cell Adhesion

Abstract Graft-versus-host-disease (GVHD) is an alloimmune response complicating allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although donor T lymphocytes and recipient antigen presenting cells (APCs) are the primarily mediators of GVHD, the molecular and cellular basis are not well understood. Recent published studies investigated T cell migration and homing in GVHD, especially effects of adhesion molecules including chemokines and integrins. Intermediate filaments (IFs) are cytoskeletal polymers encoded by a large family of differentially expressed genes that provide crucial structural support. As the most abundant IF protein and the only known IF protein in leukocytes, vimentin plays an important role in stabilizing intracellular architecture, maintaining cellular integrity and providing resistance against stress. Vimentin-deficient (Vim-/-) mice are viable with impaired wound healing, and defects in PMN and lymphocyte adhesion to endothelial cells. In addition, Vimentin has been reported to be involved in colitis, Crohn's disease and allograft rejection. Herein, we report that vimentin regulates the organization of proteins in cell adhesion, migration and signaling, all of which are important for T cell activation in GVHD. Using homotypic aggregation assay, we found there was significantly reduced aggregation of primary T cells isolated from Vim-/- mice compared to WT control. However, the expression of both LFA-1 and ICAM-1 are similar between WT and Vim-/- T cells, thus the reduced T cell adhesion is not attributed to LFA-1 expression. We further investigated whether vimentin regulates mouse primary T cell proliferation upon activation in mixed lymphocyte reactions (MLR), and demonstrated there was a significant reduction of both CD4+ and CD8+ T cell proliferation in the absence of vimentin (Vim-/-) compared to WT control. Moreover, the frequency of IFN-γ (Th1) and IL-17 (Th17) producing CD4+ cells was significantly reduced in T cells isolated from Vim-/- mice compared to WT control. To investigate the role of vimentin in regulating TCR-induced activation, we examined the immune synapse formation in mouse CD8+ T cells, and found vimentin was enriched proximal to the membrane and associated with the prominent CD3/LFA-1 cluster upon TCR stimulation. In the control without any TCR stimulation, the predominant pattern was different with vimentin evenly distributed beneath the cell membrane. In the absence of vimentin (Vim-/-), immune synapse failed to form in mouse CD8+ T cells upon TCR stimulation. The data demonstrate that vimentin can regulate immunological synapse function and signal transduction in T cell activation and proliferation. To determine whether vimentin expression in T cells plays a role in GVHD, the MHC class I and II disparate model, C57BL/6 (H-2b) to BALB/c (H-2d) transplantation, was used to establish GVHD. T cells from WT or Vim-/- (C57BL/6 background) mice were used as donors and Balb/c mice as recipients. Irradiated BALB/c mice received 5x106 T cell-depleted bone marrow cells (WT) and 10×106 T cells (WT or Vim-/-). In comparison to WT control, mice received Vim-/- T cells showed a lower mortality rate. Within 8 weeks post-transplantation, about 65% of mice received Vim-/- T cells survived, compared with only less than 10% of control mice received WT T cells (P=0.036; n=15 in each group). Control recipients had severe GVHD in the skin, intestine and liver. Mice received Vim-/- T cells exhibited only mild changes in these organs, reflected in their significantly lower GVHD scores. There were significantly reduced donor-derived CD4+ and CD8+ T cells in secondary lymphoid organs. Thus, the reduced homing and proliferation of Vim-/- T cells in vivo led to the reduced mortality and morbidity associated with GVHD. In summary, we have shown that there are significantly reduced T cell adhesion, proliferation and Th1/17 polarization in Vim-/- T cells, and vimentin participates in TCR clustering and immunological synapse formation in CD8+ T cells. Furthermore, vimentin plays an important role in GVHD through regulating donor T cell adhesion, proliferation and activation. Our data will not only significantly advance our knowledge of GVHD, but also define a new function of vimentin and IF proteins in health and diseases, and thus provide a rationale for using vimentin inhibitors as potential novel therapeutic interventions for GVHD. Disclosures No relevant conflicts of interest to declare.

scholarly journals Immunomodulatory effects of different intravenous immunoglobulin preparations in chronic lymphocytic leukemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Colado ◽  
Esteban Enrique Elías ◽  
Valeria Judith Sarapura Martínez ◽  
Gregorio Cordini ◽  
Pablo Morande ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocytic Leukemia ◽  
Immunomodulatory Effects ◽  
Immunoglobulin Preparations

AbstractHypogammaglobulinemia is the most frequently observed immune defect in chronic lymphocytic leukemia (CLL). Although CLL patients usually have low serum levels of all isotypes (IgG, IgM and IgA), standard immunoglobulin (Ig) preparations for replacement therapy administrated to these patients contain more than 95% of IgG. Pentaglobin is an Ig preparation of intravenous application (IVIg) enriched with IgM and IgA (IVIgGMA), with the potential benefit to restore the Ig levels of all isotypes. Because IVIg preparations at high doses have well-documented anti-inflammatory and immunomodulatory effects, we aimed to evaluate the capacity of Pentaglobin and a standard IVIg preparation to affect leukemic and T cells from CLL patients. In contrast to standard IVIg, we found that IVIgGMA did not modify T cell activation and had a lower inhibitory effect on T cell proliferation. Regarding the activation of leukemic B cells through BCR, it was similarly reduced by both IVIgGMA and IVIgG. None of these IVIg preparations modified spontaneous apoptosis of T or leukemic B cells. However, the addition of IVIgGMA on in vitro cultures decreased the apoptosis of T cells induced by the BCL-2 inhibitor, venetoclax. Importantly, IVIgGMA did not impair venetoclax-induced apoptosis of leukemic B cells. Overall, our results add new data on the effects of different preparations of IVIg in CLL, and show that the IgM/IgA enriched preparation not only affects relevant mechanisms involved in CLL pathogenesis but also has a particular profile of immunomodulatory effects on T cells that deserves further investigation.

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

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.

EP.WE.805From bench to bedside; A rationale for Immunotherapy in the adjuvant setting for Oesophageal cancer

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Noel Donlon ◽  
Maria Davern ◽  
Andrew Sheppard ◽  
John Reynolds ◽  
Joanne Lysaght
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Cell Activation ◽  
Single Agent ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Post Surgery ◽  
Post Operative Period

Abstract Background Immunotherapy is being intensively investigated for its utilisation in the curative setting as a single agent and in the multimodal setting, however, the most appropriate time to incorporate ICIs remains unknown. Our study profiles systemic anti-tumour immunity perioperatively to provide a rationale for adjuvant immunotherapy. Methods Systemic immunity was immunophenotyped pre and post-oesophagectomy on days 0, 1, 3, 7 and week 6 by flow cytometry (n = 14). The frequency of circulating lymphocytes, T cells, cytotoxic and helper T lymphocytes was profiled longitudinally including the proportion of T cell subsets in circulation. This study also profiled immune checkpoint expression on circulating T cells including: PD-1, CTLA-4, TIGIT, TIM-3, LAG-3, PD-L1 and PD-L2. Markers of immunogenicity (calreticulin, HMGB1 and MIC-A/B) were also assessed. Results The frequency of circulating CD27 + T cells increases sequentially in the immediate post-operative period peaking on day 7 in OAC patients. (p &lt; 0.01) There is a sequential decrease in the percentage of effector memory and central memory T cells in circulation and an increase in the percentage of naïve T cells in peripheral circulation of OAC patients in the immediate post-operative period. The expression of CTLA-4 on the surface of circulating CD4 + T cells decreases 6 weeks post-operatively in OAC patients. Conclusions We observed increased T cell activation and immune checkpoints immediately post-surgery with returns to baseline by week 6. These results suggest that immune checkpoint inhibitors such as anti-PD-1 may be beneficial immediately post-surgery to maintain T cell activation and prevent exhaustion of this increased population of activated T cells observed immediately post-surgery.

scholarly journals A novel form of immune signaling revealed by transmission of the inflammatory mediator serotonin between dendritic cells and T cells

Blood ◽  
2006 ◽  
Vol 107 (3) ◽  
pp. 1010-1017 ◽  
Author(s):  
Peta J. O'Connell ◽  
Xiangbin Wang ◽  
Matilde Leon-Ponte ◽  
Corrie Griffiths ◽  
Sandeep C. Pingle ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Activated T Cells ◽  
Immune Synapse ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
5 Ht Uptake

AbstractAdaptive immunity is triggered at the immune synapse, where peptide-major histocompatibility complexes and costimulatory molecules expressed by dendritic cells (DCs) are physically presented to T cells. Here we describe transmission of the inflammatory monoamine serotonin (5-hydroxytryptamine [5-HT]) between these cells. DCs take up 5-HT from the microenvironment and from activated T cells (that synthesize 5-HT) and this uptake is inhibited by the antidepressant, fluoxetine. Expression of 5-HT transporters (SERTs) is regulated by DC maturation, exposure to microbial stimuli, and physical interactions with T cells. Significantly, 5-HT sequestered by DCs is stored within LAMP-1+ vesicles and subsequently released via Ca2+-dependent exocytosis, which was confirmed by amperometric recordings. In turn, extracellular 5-HT can reduce T-cell levels of cAMP, a modulator of T-cell activation. Thus, through the uptake of 5-HT at sites of inflammation, and from activated T cells, DCs may shuttle 5-HT to naive T cells and thereby modulate T-cell proliferation and differentiation. These data constitute the first direct measurement of triggered exocytosis by DCs and reveal a new and rapid type of signaling that may be optimized by the intimate synaptic environment between DCs and T cells. Moreover, these results highlight an important role for 5-HT signaling in immune function and the potential consequences of commonly used drugs that target 5-HT uptake and release.

Molecular transfer of CD40 and OX40 ligands to leukemic human B cells induces expansion of autologous tumor–reactive cytotoxic T lymphocytes

Blood ◽  
2005 ◽  
Vol 105 (6) ◽  
pp. 2436-2442 ◽  
Author(s):  
Ettore Biagi ◽  
Gianpietro Dotti ◽  
Eric Yvon ◽  
Edward Lee ◽  
Martin Pule ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Antibody Therapy ◽  
Interferon Γ ◽  
Lymphocytic Leukemia ◽  
Cytotoxic T Cell ◽  
Autologous Tumor ◽  
Molecular Transfer

AbstractClinical benefits from monoclonal antibody therapy for B-chronic lymphocytic leukemia (B-CLL) have increased interest in developing additional immunotherapies for the disease. CD40 ligand is an accessory signal for T-cell activation and can overcome T-cell anergy. The OX40-OX40 ligand pathway is involved in the subsequent expansion of memory antigen-specific T cells. We expressed both CD40L and OX40L on B-CLL cells by exploiting the phenomenon of molecular transfer from fibroblasts overexpressing these ligands. We analyzed the effects of the modified B-CLL cells on the number, phenotype, and cytotoxic function of autologous T cells in 7 B-CLL patients. Transfer of CD40L and OX40L was observed in all and was followed by the up-regulation of B7-1 and B7-2. The culture of CD40L/OX40L-expressing B-CLL cells with autologous T cells generated CD4+/CD8+ cytotoxic T-cell lines, which secreted interferon-γ (IFN-γ) and granzyme-B/perforin in response to autologous, but not to allogeneic, B-CLL cells or to autologous T-cell blasts. CD40L or OX40L alone was insufficient to expand tumor-reactive T cells. The combination of CD40L and OX40L on B-CLL cells may allow the generation of therapeutic immune responses to B-CLL, either by active immunization with modified tumor cells or by adoptive immunotherapy with tumor-reactive autologous T cells.

Sign in / Sign up

Export Citation Format

Share Document