Rituximab Directly Decreases T Cell Activation, Both In Vivo and In Vitro

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3935-3935 ◽  
Author(s):  
Tamar Katz ◽  
Dina Stroopinsky ◽  
Jacob M. Rowe ◽  
Irit Avivi
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Inflammatory Cytokine ◽  
Cell Activation ◽  
Cell Function ◽  
Activation Profile

Abstract Abstract 3935 Rituximab, a chimeric anti-C20 monoclonal antibody, has been extensively used over the last decade for the therapy of B cell malignancies. Recent clinical data suggest that rituximab may affect T cell function, increasing the risk of T cell dependent infections in heavily-treated patients. The current study was designed to investigate the effect of rituximab on T cell activation and assess T cell function following the addition of rituximab to purified T cells. The T cell activation profile, dependent on rituximab administration, was evaluated in vivo and in vitro. Peripheral blood mononuclear cells (PBMCs) generated from B-cell non-Hodgkin lymphoma (NHL) patients prior and immediately after the administration of 375 mg/m2 rituximab, were examined for the expression of inflammatory cytokines. The in vitro studies were performed by using CD25 depleted PBMCs or B cell depleted T cells (CD3+CD25-CD19-). The obtained cells were stimulated with allogeneic dendritic cells (DCs), in the absence or presence or 2 mg/ml rituximab. T cell activation was evaluated using immunophenotypic markers, cytokine profile and T cell proliferation assay. Eight NHL patients participated in the study. The level of T cells expressing inflammatory cytokines was significantly decreased following the administration of a single dose of rituximab. T cells expressing IL-2 declined from a mean level of 26.5% to 11.5% and the level of IFN- γ decreased from 22% to 4.2%. Further administration of rituximab, up to 4 weekly doses, resulted in an additional decline in the amount of inflammatory cytokine producing T cells to a level of 1.4% for IL-2 and 3.5% for IFN-g. However, repeated evaluation, performed at 4 months after completing rituximab, showed restoration of the inflammatory population. In accord with this inhibitory effect, in vitro stimulation of T cells with allogeneic DCs, in the presence of rituximab, resulted in a significant decrease in activation markers (CD25, GITR and CTLA-4) (Table 1). These changes were accompanied by a marked reduction in inflammatory cytokine production and proliferative capacity. Of interest, these inhibitory effects were also obtained whilst using B cell depleted T cells (CD3+CD25-CD19-). In conclusion, rituximab administration results in a transient T cell inactivation, demonstrated through the reduction in inflammatory cytokine production and T cell proliferation capacity. This effect appears to be non-B cell dependent, being obtained in the absence of B cell in the culture, and may account for clinical observations in ameliorating T-cell dependent disorders, such as graft-versus-host disease. Table 1. Activation profile depending on rituximab (in vitro) Without rituximab With rituximab *Activation marker (%) CD25 27 9 GITR 15.6 4.7 CTLA4 17.7 7 *Cytokines expression (%) IL-2 22 2 IL12 16 4 IFN-gamma 21 1.8 T cells proliferation (O.D.) DC stimulation 1.528 0.580 CMV stimulation 1.563 0.570 anti CD3/CD28 stimulation 0.705 0.407 * Gated out of lymphocytes Disclosures: No relevant conflicts of interest to declare.

scholarly journals TRPM2 Is Not Required for T-Cell Activation and Differentiation

2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

scholarly journals A Novel Fully Human Bispecific CD19 x CD3 Antibody That Kills Lymphoma Cells with Minimal Cytokine Secretion

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1671-1671
Author(s):  
Harbani Malik ◽  
Ben Buelow ◽  
Brian Avanzino ◽  
Aarti Balasubramani ◽  
Andrew Boudreau ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Secretion ◽  
Lymphoma Cells ◽  
Nog Mice

Abstract Introduction Along with CD20 and CD22, the restricted expression of CD19 to the B-cell lineage makes it an attractive target for the therapeutic treatment of B-cell malignancies. Many monoclonal antibodies and antibody drug conjugates specific to CD19 have been described, including bispecific T-cell redirecting antibodies (T-BsAbs). In addition, anti-CD19 chimeric antigen receptor T-cells (CAR-Ts) have been approved to treat leukemia. To date, toxicity from over-activation of T-cells and large-scale production of CAR-Ts still hinder this approach. Bispecific T-cell engaging antibodies redirecting T cells to CD19 circumvent the latter problem but to date have shown similar T-cell over-activation, as well as significant neurotoxicity. Utilizing TeneoSeek, a next generation sequencing (NGS)-based discovery pipeline that uses in silico analysis of heavy chain only/fixed light chain antibody (HCA/Flic, respectively) sequences to enrich for antigen specific antibodies, we made a high affinity αCD19 HCA and a library of αCD3 Flic antibodies that showed a >2 log range of EC50s for T cell activation in vitro. Of note, the library contained a selectively-activating αCD3 that induced potent T-cell dependent lysis of lymphoma cells (when paired with an αCD19 HCA) with minimal cytokine secretion. To characterize the relative efficacy and potential therapeutic window of this unique molecule, we compared the low-activating (and Fc-containing) CD19 x CD3 to two pan T-cell activating bispecific CD19 x CD3 antibodies (blinatumomab and another developed in-house) in vitro and in vivo for T-cell activation, efficacy in killing lymphoma cells, and toxicity. Methods T-cell activation was measured via flow cytometry (CD69 and CD25 expression) and cytokine ELISA (IL-2, IL-6, IL-10, INF-ɣ, and TNFα) in vitro. Lysis of B-cell tumor cell lines (Raji, Ramos, and Nalm6) was measured via calcein release in vitro. In vivo, NOG mice were engrafted with human peripheral blood mononuclear cells (huPBMC) and human lymphoma cell lines, and the mice treated with weekly injections of T-BsAbs. Tumor burden was evaluated via caliper measurement. Pharmacokinetic (PK) studies were performed in NOG mice using ELISA. Results EC50s for cytotoxicity were in the single-digit nanomolar range for the selective T cell activating T-BsAb and sub-nanomolar for the pan T-cell activating controls. The selective T cell activator showed markedly reduced cytokine release for all cytokines tested compared to the pan T-cell controls even at saturating concentrations. In vivo, established CD19 positive B-cell tumors were cleared in NOG mice in the presence of huPBMC. PK profiles of both molecules generated in-house (selective and pan T-cell activators) were consistent with those of an IgG in mice. No activation of T-cells was observed in vitro or in vivo in the absence of CD19 expressing target cells. Conclusions Both the selectively-activating and the pan T-cell activating control bispecific antibodies killed lymphoma cells in vitro and in vivo in a CD19-dependent manner. While the pan T-cell activating controls showed T-cell activation comparable to other CD3-engaging bispecifics, the selective activator induced significantly reduced cytokine secretion by T-cells and demonstrated a half-life consistent with other IgG antibodies. In summary, our selectively activating CD19 x CD3 T-BsAb shows promise as a lymphoma therapeutic differentiated from current T-cell targeted therapies currently in the clinic and in clinical trials. Disclosures Malik: Teneobio, Inc.: Employment. Buelow:Teneobio Inc.: Employment. Avanzino:Teneobio, Inc.: Employment. Balasubramani:Teneobio, Inc.: Employment. Boudreau:Teneobio, Inc.: Employment. Clarke:Teneobio, Inc.: Employment. Dang:Teneobio, Inc.: Employment. Davison:Teneobio, Inc.: Employment. Force Aldred:Teneobio Inc.: Employment. Harris:Teneobio, Inc.: Employment. Jorgensen:Teneobio, Inc.: Employment. Li:Teneobio, Inc.: Employment. Medlari:Teneobio, Inc.: Employment. Narayan:Teneobio, Inc.: Employment. Ogana:Teneobio, Inc.: Employment. Pham:Teneobio Inc.: Employment. Prabhakar:Teneobio, Inc.: Employment. Rangaswamy:Teneobio, Inc.: Employment. Sankaran:Teneobio, Inc.: Employment. Schellenberger:Teneobio, Inc.: Employment. Ugamraj:Teneobio, Inc.: Employment. Trinklein:Teneobio, Inc.: Employment. Van Schooten:Teneobio, Inc.: Employment.

A T Cell-Engaging CD3 Recruit-Tandab Potently Kills CD19+ Tumor B Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3721-3721
Author(s):  
Eugene Zhukovsky ◽  
Uwe Reusch ◽  
Carmen Burkhardt ◽  
Stefan Knackmuss ◽  
Ivica Fucek ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Cells ◽  
Cytotoxicity Assays

Abstract Abstract 3721 Background: CD19 is expressed from early B cell development through differentiation into plasma cells, and is an attractive alternative to CD20 as a target for the development of therapeutic antibodies to treat B cell malignancies. T cells are potent tumor-killing effector cells that cannot be recruited by native antibodies. The CD3 RECRUIT-TandAb AFM11, a humanized bispecific tetravalent antibody with two binding sites for both CD3 and CD19, is a novel therapeutic for the treatment of NHL that harnesses the cytotoxic nature of T cells. Methods: We engineered a bispecific anti-CD19/anti-CD3e tetravalent TandAb with humanized and affinity-matured variable domains. The TandAb's binding properties, T cell-mediated cytotoxic activity, and target-mediated T cell activation were characterized in a panel of in vitro assays. In vivo efficacy was evaluated in a murine NOD/scid xenograft model reconstituted with human PBMC. Results: AFM11 mediates highly potent CD19+ tumor cell lysis in cytotoxicity assays performed on a panel of cell lines (JOK-1, Raji, Nalm-6, MEC-1, VAL, Daudi) and primary B-CLL tumors: EC50 values are in the low- to sub-picomolar range and do not correlate with the expression density of CD19 on the target cell lines. The cytotoxic activity of tetravalent AFM11 is superior to that of alternative bivalent antibody formats possessing only a single binding site for both CD19 and CD3. High affinity binding of AFM11 to CD19 and to CD3 is essential for efficacious T cell recruitment. Both CD8+ and CD4+ T cells mediate cytotoxicity however the former exhibit much faster killing. We observe that AFM11 displays similar cytotoxic efficacy at different effector to target ratios (from 5:1 to 1:5) in cytotoxicity assays; this suggests that T cells are engaged in the serial killing of CD19+ target cells. In the absence of CD19+ target cells in vitro, AFM11 does not elicit T cell activation as manifested by cytokine release (from a panel of ten cytokines associated with T cell activation), their proliferation, or their expression of activation markers. AFM11 activates T cells exclusively in the presence of its targets and mediates lysis of CD19+ cells while sparing antigen-negative bystanders. In the absence of CD19+ target cells, AFM11 concentrations in excess of 500-fold over EC50 induce down-modulation of the CD3/TCR complex. Yet, AFM11-treated T cells can be re-engaged for target cell lysis. All of these features of AFM11-induced T cell activation may contribute additional safety without compromising its efficacy. In vivo AFM11 demonstrates a robust dose-dependent inhibition of subcutaneous Raji tumors in mice. At 5 mg/kg AFM11 demonstrates a complete suppression of tumor growth, and even at 5 ug/kg tumor growth is reduced by 60%. Moreover, we observe that a single administration of AFM11 produces inhibition of tumor growth similar to that of 5 consecutive administrations. Conclusions: In summary, our in vitro and in vivo experiments with AFM11 demonstrate the high potency and efficacy of its anti-tumor cytotoxicity. Thus, AFM11 is a novel highly efficacious drug candidate for the treatment of B cell malignancies with an advantageous safety profile. Disclosures: Zhukovsky: Affimed Therapeutics AG: Employment, Equity Ownership. Reusch:Affimed Therapeutics AG: Employment. Burkhardt:Affimed Therapeutics AG: Employment. Knackmuss:Affimed Therapeutics AG: Employment. Fucek:Affimed Therapeutics AG: Employment. Eser:Affimed Therapeutics AG: Employment. McAleese:Affimed Therapeutics AG: Employment. Ellwanger:Affimed Therapeutics AG: Employment.

scholarly journals Mouse CD19-Targeted Chimeric Antigen Receptors That Include a 41BB Co-Stimulatory Domain Induce NFkB Signaling to Enhance T Cell Proliferation, Viability, and Leukemia Killing

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 843-843
Author(s):  
Gongbo Li ◽  
Nolan Beatty ◽  
Paresh Vishwasrao ◽  
Justin C. Boucher ◽  
Bin Yu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Car T Cells ◽  
Apoptosis Protein ◽  
Car T

Abstract CD19 targeted 2nd generation chimeric antigen receptor T (CAR T) cells have been successful against relapsed and/or refractory B cell malignancies. The pending FDA-approval of 2 separate CD19 targeted CAR T products highlight the need to understand the biology behind this novel therapy. CAR design includes a single-chain variable fragment, which encodes antigen-binding, fused to a transmembrane domain, co-stimulatory domain, and CD3ζ activation domain. The two CARs likely to be approved as standard of care include a 41BB or CD28 co-stimulatory domain. CD28 is a critical co-stimulatory receptor required for full T cell activation and persistence, while 4-1BB is a member of the tumor necrosis factor receptor family and also a critical T cell co-stimulatory factor. Early evaluation of the co-stimulatory domains role in CAR design confirmed that they are required to enhance T cell function, but lacked insight regarding their mechanism for this enhancement. Furthermore, clinical outcomes suggest that the co-stimulatory domains in CARs support different T cell functions in patients. For example, while overall outcomes are similar between 41BB (19BBz) and CD28-containing CARs (1928z), 19BBz CAR T cells can persist for years in patients, but functional 1928z CAR T cells rarely persist longer than a month. Recent studies are providing insight to these differences and have demonstrated that 4-1BB-containing CARs reduce T cell exhaustion, enhance persistence, and increase central memory differentiation and mitochondrial biogenesis, while CD28-containing CARs support robust T cell activation and exhaustion, and are associated with effector-like differentiation. However, these studies have been performed mostly in vitro or in immune deficient mice, which limits their ability to model complex immune biology. Therefore, we evaluated murine CD19-targeting CARs with a 4-1BB (m19BBz) or CD28- (m1928z) co-stimulatory domain in relevant animal models of immunity. We directly compared m19BBz and m1928z CAR T cell immune phenotype, cytotoxicity, cytokine production, gene expression, intracellular signaling, and in vivo persistence, expansion, and B cell acute lymphoblastic leukemia (B-ALL) eradication. In vitro assays revealed that m1928z CAR T cells had enhanced cytotoxicity and cytokine production compared to m19BBz CAR T cells. Also, evaluation of m1928z and m19BBz CAR T cells displayed similar immune phenotypes, but markedly different gene expression with m1928z CAR T cells upregulating genes related to effector function and exhaustion, while m19BBz CAR upregulated genes critical for NFkB regulation, T cell quiescence and memory. In vivo, both m1928z and m19BBz CAR T cells supported equivalent protection against B-ALL. Similar to patients, in our mouse models there are functional differences between the mouse CD19-targeted CAR T cells. At 1 week post-infusion m19BBz CAR T cells are present in the blood of mice at significantly greater levels than m1928z CAR T cells. Furthermore, m19BBz CAR T cells enhance proliferation and/or anti-apoptosis protein expression to enhance B cell killing, which is evidenced by our observation that irradiation significantly weakens the in vivo efficacy of m19BBz but not m1928z CAR T cells. Our results suggest that B cell killing by m1928z CAR T cells is not impacted by irradiation because of their efficacious cytotoxicity of B cells. In contrast, m19BBz CAR T cells have enhanced viability and anti-apoptosis protein expression, which allows them to compensate for reduced effector function. We investigated potential mechanisms for the enhanced viability and anti-apoptosis of m19BBz CAR T cells and determined that NFkB signaling is upregulated much greater by m19BBz than m1928z. We have observed this difference in both a reporter cell line and primary mouse T cells. We are now dissecting what cellular components mediate increased NFkB signaling by the m19BBz CAR. Our animal models recapitulate equivalent anti-leukemia efficacy of CD19-targeted CAR T cells regardless of co-stimulatory domain, but underscore that anti-leukemia killing is mediated by different methods depending on the co-stimulatory domain. Our work sheds light on how 4-1BB mechanistically regulates and impacts CAR T function and has implications for future CAR design and evaluation. Disclosures No relevant conflicts of interest to declare.

scholarly journals A population of CD4+ T cells with a naïve phenotype stably polarized to the TH1 lineage

2020 ◽  
Author(s):  
Jonathan W. Lo ◽  
Maria Vila de Mucha ◽  
Luke B. Roberts ◽  
Natividad Garrido-Mesa ◽  
Arnulf Hertweck ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
T Cell Subsets ◽  
T Helper

AbstractT-bet is the lineage-specifying transcription factor for CD4+ T helper type 1 (TH1) cells. T-bet has also been found in other CD4+ T cell subsets, including TH17 cells and TREG, where it modulates their functional characteristics. However, we lack information on when and where T-bet is expressed during T cell differentiation and how this impacts T cell function. To address this, we traced the ontogeny of T-bet-expressing cells using a fluorescent fate-mapping mouse line. We demonstrate that T-bet is expressed in a subset of CD4+ T cells with naïve cell surface markers and that this novel cell population is phenotypically and functionally distinct from conventional naïve CD4+ T cells. These cells are also distinct from previously described populations of memory phenotype and stem cell-like T cells. Naïve-like T-bet-experienced cells are polarised to the TH1 lineage, predisposed to produce IFNγ upon cell activation, and resist repolarisation to other lineages in vitro and in vivo. These results demonstrate that lineage-specifying factors can function to polarise T cells in the absence of canonical markers of T cell activation and that this has an impact on the subsequent T helper response.

scholarly journals Combinatorial Control of Signal-Induced Exon Repression by hnRNP L and PSF

2007 ◽  
Vol 27 (19) ◽  
pp. 6972-6984 ◽  
Author(s):  
Alexis A. Melton ◽  
Jason Jackson ◽  
Jiarong Wang ◽  
Kristen W. Lynch
Keyword(s):  
T Cells ◽  
Alternative Splicing ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Exon Skipping ◽  
Dependent Manner

ABSTRACT Cells can regulate their protein repertoire in response to extracellular stimuli via alternative splicing; however, the mechanisms controlling this process are poorly understood. The CD45 gene undergoes alternative splicing in response to T-cell activation to regulate T-cell function. The ESS1 splicing silencer in CD45 exon 4 confers basal exon skipping in resting T cells through the activity of hnRNP L and confers activation-induced exon skipping in T cells via previously unknown mechanisms. Here we have developed an in vitro splicing assay that recapitulates the signal-induced alternative splicing of CD45 and demonstrate that cellular stimulation leads to two changes to the ESS1-bound splicing regulatory complex. Activation-induced posttranslational modification of hnRNP L correlates with a modest increase in the protein's repressive activity. More importantly, the splicing factor PSF is recruited to the ESS1 complex in an activation-dependent manner and accounts for the majority of the signal-regulated ESS1 activity. The associations of hnRNP L and PSF with the ESS1 complex are largely independent of each other, but together these proteins account for the total signal-regulated change in CD45 splicing observed in vitro and in vivo. Such a combinatorial effect on splicing allows for precise regulation of signal-induced alternative splicing.

107 Effects of IL-2 and IL-15 on the proliferative and antitumor capacities of allogeneic CD20 CAR-engineered γδ T cells in a 3D B cell lymphoma spheroid assay

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Γδ T Cells ◽  
Γδ T Cell ◽  
Car T

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.

scholarly journals Modulating p56Lck in T-Cells by a Chimeric Peptide Comprising Two Functionally Different Motifs of Tip fromHerpesvirus saimiri

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
Jean-Paul Vernot ◽  
Ana María Perdomo-Arciniegas ◽  
Luis Alberto Pérez-Quintero ◽  
Diego Fernando Martínez
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lipid Rafts ◽  
T Cell Activation ◽  
Cell Activation ◽  
Jurkat Cells ◽  
Chimeric Peptide ◽  
Vector Targeting

The Lck interacting protein Tip ofHerpesvirus saimiriis responsible for T-cell transformation bothin vitroandin vivo. Here we designed the chimeric peptide hTip-CSKH, comprising the Lck specific interacting motif CSKH of Tip and its hydrophobic transmembrane sequence (hTip), the latter as a vector targeting lipid rafts. We found that hTip-CSKH can induce a fivefold increase in proliferation of human andAotussp. T-cells. Costimulation with PMA did not enhance this proliferation rate, suggesting that hTip-CSKH is sufficient and independent of further PKC stimulation. We also found that human Lck phosphorylation was increased earlier after stimulation when T-cells were incubated previously with hTip-CSKH, supporting a strong signalling and proliferative effect of the chimeric peptide. Additionally, Lck downstream signalling was evident with hTip-CSKH but not with control peptides. Importantly, hTip-CSKH could be identified in heavy lipid rafts membrane fractions, a compartment where important T-cell signalling molecules (LAT, Ras, and Lck) are present during T-cell activation. Interestingly, hTip-CSKH was inhibitory to Jurkat cells, in total agreement with the different signalling pathways and activation requirements of this leukemic cell line. These results provide the basis for the development of new compounds capable of modulating therapeutic targets present in lipid rafts.

T cell-T cell activation in multiple sclerosis

1997 ◽  
Vol 3 (4) ◽  
pp. 238-242 ◽  
Author(s):  
JW Lindsey ◽  
RH Kerman ◽  
JS Wolinsky
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Viral Infections ◽  
Activated T Cells ◽  
In Vitro Proliferation

Activated T cells are able to stimulate proliferation in resting T cells through an antigen non-specific mechanism. The in vivo usefulness of this T cell-T cell activation is unclear, but it may serve to amplify immune responses. T cell-T cell activation could be involved in the well-documented occurrence of multiple sclerosis (MS) exacerbations following viral infections. Excessive activation via this pathway could also be a factor in the etiology of MS. We tested the hypothesis that excessive T cell-T cell activation occurs in MS patients using in vitro proliferation assays comparing T cells from MS patients to T cells from controls. When tested as responder cells, T cells from MS patients proliferated slightly less after stimulation with previously activated cells than T cells from controls. When tested as stimulator cells, activated cells from MS patients stimulated slightly more non-specific proliferation than activated cells from controls. Neither of these differences were statistically significant We conclude that T cell proliferation in response to activated T cells is similar in MS and controls.

scholarly journals Signaling function of PRC2 is essential for TCR-driven T cell responses

2018 ◽  
Vol 215 (4) ◽  
pp. 1101-1113 ◽  
Author(s):  
Marc-Werner Dobenecker ◽  
Joon Seok Park ◽  
Jonas Marcello ◽  
Michael T. McCabe ◽  
Richard Gregory ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Therapeutic Potential ◽  
Cell Types ◽  
Polycomb Repressive Complex 2 ◽  
Histone Lysine Methyltransferases

Differentiation and activation of T cells require the activity of numerous histone lysine methyltransferases (HMT) that control the transcriptional T cell output. One of the most potent regulators of T cell differentiation is the HMT Ezh2. Ezh2 is a key enzymatic component of polycomb repressive complex 2 (PRC2), which silences gene expression by histone H3 di/tri-methylation at lysine 27. Surprisingly, in many cell types, including T cells, Ezh2 is localized in both the nucleus and the cytosol. Here we show the presence of a nuclear-like PRC2 complex in T cell cytosol and demonstrate a role of cytosolic PRC2 in T cell antigen receptor (TCR)–mediated signaling. We show that short-term suppression of PRC2 precludes TCR-driven T cell activation in vitro. We also demonstrate that pharmacological inhibition of PRC2 in vivo greatly attenuates the severe T cell–driven autoimmunity caused by regulatory T cell depletion. Our data reveal cytoplasmic PRC2 is one of the most potent regulators of T cell activation and point toward the therapeutic potential of PRC2 inhibitors for the treatment of T cell–driven autoimmune diseases.

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