scholarly journals Regulation of T Cell-Mediated Hepatic Inflammation by Adiponectin and Leptin

Endocrinology ◽  
2005 ◽  
Vol 146 (5) ◽  
pp. 2157-2164 ◽  
Author(s):  
Joseph A. Sennello ◽  
Raja Fayad ◽  
Alison M. Morris ◽  
Robert H. Eckel ◽  
Esra Asilmaz ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Contrast Administration ◽  
Cytokine Levels ◽  
Hepatotoxic Effect ◽  
Killer T Cells

Abstract Concanavalin A-induced hepatotoxicity was compared in lipodystrophic aP2-nSREBP-1c transgenic mice (LD mice) lacking adipose tissue, obese leptin-deficient ob/ob mice, and lean wild-type (WT) mice. Serum leptin and adiponectin were low in LD mice, whereas ob/ob mice had undetectable leptin, but high adiponectin. Protection from hepatotoxicity was observed in ob/ob, but not in LD mice, despite low cytokine levels and reduced T cell activation and hepatic natural killer T cells in both groups. Administration of adiponectin protected LD mice from hepatotoxicity without altering cytokine levels. In contrast, administration of leptin heightened disease susceptibility by restoring cytokine production. Neutralization of TNFα protected LD mice from liver damage. Increased in vivo susceptibility to the hepatotoxic effect of TNFα was observed in LD mice. In vitro, adiponectin protected primary hepatocytes from TNFα-induced death, whereas leptin had no protective effect. In conclusion, although leptin increases susceptibility to hepatotoxicity by regulating cytokine production and T cell activation, adiponectin protects hepatocytes from TNFα-induced death.

613 HER2-XPAT, a novel protease-activatable prodrug T cell engager (TCE), with potent T-cell activation and efficacy in solid tumors and large predicted safety margins in non-human primate (NHP)

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A649-A649
Author(s):  
Fiore Cattaruzza ◽  
Ayesha Nazeer ◽  
Zachary Lange ◽  
Caitlin Koski ◽  
Mikhail Hammond ◽  
...  
Keyword(s):  
T Cell ◽  
Solid Tumors ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Antigenic Specificity ◽  
The Core ◽  
Protease Cleavage ◽  
Safety Margins

BackgroundTCEs are effective in leukemias but have been challenging in solid tumors due to on-target, off-tumor toxicity. Attempts to circumvent CRS include step-up dosing and/or complex designs but are unsuccessful due to toxicity and/or enhanced immunogenicity. HER2-XPAT, or XTENylated Protease-Activated bispecific T-Cell Engager, is a prodrug TCE that exploits the protease activity present in tumors vs. healthy tissue to expand the therapeutic index (TI). The core of the HER2-XPAT (PAT) consists of 2 tandem scFvs targeting CD3 and HER2. Attached to the core, two unstructured polypeptide masks (XTEN) sterically reduce target engagement and extend T1/2. Protease cleavage sites at the base of the XTEN masks enable proteolytic activation of XPATs in the tumor microenvironment, unleashing a potent TCE with short T1/2, further improving the TI. HER2-XPAT, a tumor protease-activatable prodrug with wide safety margins, can co-opt T-cells regardless of antigenic specificity to induce T-cell killing of HER2+ tumors.MethodsPreclinical studies were conducted to characterize the activity of HER2-XPAT, HER2-PAT (cleaved XPAT), and HER2-NonClv (a non-cleavable XPAT) for cytotoxicity in vitro, for anti-tumor efficacy in xenograft models, and for safety in NHPs.ResultsHER2-PAT demonstrated potent in vitro T-cell cytotoxicity (EC50 1-2pM) and target-dependent T-cell activation and cytokine production by hPBMCs. HER2-XPAT provided up to 14,000-fold protection against killing of HER2 tumor cells and no cytotoxicity against cardiomyocytes up to 1uM. In vivo, HER2-XPAT induced complete tumor regressions in BT-474 tumors with equimolar dosing to HER2-PAT, whereas HER2-NonClv had no efficacy, supporting requirement of protease cleavage for T-cell activity. In NHP, HER2-XPAT has been dose-escalated safely up to 42mg/kg (MTD). HER2-XPAT demonstrated early T-cell margination at 2 mg/kg but largely spared CRS, cytokine production, and tissue toxicity up to 42 mg/kg. PK profiles of HER2-XPAT and HER2-NonClv were comparable, consistent with ex vivo stability for cleavage when incubated in cancer pts plasma for 7 days at 37°C. HER2-PAT by continuous infusion induced lethal CRS and cytokine spikes at 0.3 mg/kg/d but was tolerated at 0.25 mg/kg/d, providing HER2-XPAT with >1300-fold protection in tolerability vs. HER2-PAT, >4 logs over cytotoxicity EC50s for HER2 cell lines, and a 20-fold safety margin over the dose required for pharmacodynamic activity.ConclusionsHER2-XPAT is a potent prodrug TCE with no CRS and a wide TI based on NHPs. With XTEN’s clinical data demonstrating low immunogenicity, the XPATs are a promising solution. IND studies are ongoing. Additional PK/PD, cytokines, safety, and efficacy data will be presented.

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 Programmed cell death 1 forms negative costimulatory microclusters that directly inhibit T cell receptor signaling by recruiting phosphatase SHP2

2012 ◽  
Vol 209 (6) ◽  
pp. 1201-1217 ◽  
Author(s):  
Tadashi Yokosuka ◽  
Masako Takamatsu ◽  
Wakana Kobayashi-Imanishi ◽  
Akiko Hashimoto-Tane ◽  
Miyuki Azuma ◽  
...  
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
T Cell Activation ◽  
Cell Activation ◽  
Tyrosine Phosphatase ◽  
Cell Receptor ◽  
Programmed Cell Death 1

Programmed cell death 1 (PD-1) is a negative costimulatory receptor critical for the suppression of T cell activation in vitro and in vivo. Single cell imaging elucidated a molecular mechanism of PD-1–mediated suppression. PD-1 becomes clustered with T cell receptors (TCRs) upon binding to its ligand PD-L1 and is transiently associated with the phosphatase SHP2 (Src homology 2 domain–containing tyrosine phosphatase 2). These negative costimulatory microclusters induce the dephosphorylation of the proximal TCR signaling molecules. This results in the suppression of T cell activation and blockade of the TCR-induced stop signal. In addition to PD-1 clustering, PD-1–TCR colocalization within microclusters is required for efficient PD-1–mediated suppression. This inhibitory mechanism also functions in PD-1hi T cells generated in vivo and can be overridden by a neutralizing anti–PD-L1 antibody. Therefore, PD-1 microcluster formation is important for regulation of T cell activation.

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.

Bispecific anti-PD-1/PD-L1 antibody CTX-8371 to promote cellular clustering and PD-1 shedding, antitumor activity and tolerability.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15056-e15056
Author(s):  
Diana I. Albu ◽  
Yan Qin ◽  
Xianzhe Wang ◽  
Vivian Li ◽  
Taeg Kim ◽  
...  
Keyword(s):  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mouse Tumor ◽  
Tumor Models ◽  
Cynomolgus Monkeys ◽  
Range Finding

e15056 Background: Checkpoint blockade therapies targeting PD-1 and PD-L1 have shown great success for the treatment of various malignancies. However, a substantial fraction of patients with PD-L1-positive tumors remain unresponsive to these therapies. Novel therapy with significantly greater activity than the leading PD-1/PD-L1 inhibitors is expected to bring additional clinical benefit to patients. Here we describe the preclinical evaluation of CTX-8371, which combines anti-PD-1 and anti-PD-L1 monoclonal antibodies in one bispecific tetravalent molecule. Methods: The immune-enhancing activity of CTX-8371 was tested in vitro in T cell activation assays and tumor cell killing assay. CTX-8371 anti-tumor efficacy in vivo was assessed using mouse tumor cells expressing human PD-L1 implanted in transgenic mice humanized at the PD-1 and PD-L1 loci. CTX-8371 anti-tumor activity was also tested in xenograft tumor models. The mechanism of action of CTX-8371 was investigated in vitro using Jurkat cells expressing PD-1 or PD-L1, human PBMCs, and in vivo in tumor-bearing, chimeric PD-1/PD-L1 transgenic mice. CTX-8371 PK was determined in mice using an MSD ELISA-based assay and in cynomolgus monkeys using a qualified ELISA method. Dose range finding and toxicokinetic studies were performed in cynomolgus monkeys. Results: CTX-8371 potently enhanced T cell activation and function in vitro and showed curative efficacy as monotherapy in multiple solid tumor models, isografts or xenografts. Furthermore, CTX-8371 demonstrated superior anti-tumor efficacy compared to Keytruda or atezolizumab in checkpoint inhibitors-sensitive and resistant syngeneic mouse tumor models. Mechanistically, in addition to blocking PD-1 interaction with PD-L1, CTX-8371 bispecific antibody facilitated cell to cell bridging between cells expressing PD-1 and cells expressing PD-L1. Furthermore, we show that simultaneous binding of CTX-8371 to both PD-1 and PD-L1 resulted in long term PD-1 shedding. This suggests that CTX-8371 may prevent or overcome T cell exhaustion within the tumor microenvironment, thus providing additional advantage over existing therapies. Lastly, excellent tolerability was observed in non-human primates given 2 weekly drug infusions at up to 50 mg/kg dose. Conclusions: CTX-8371 displays multiple mechanisms of action over monoclonal PD1/PD-L1 blockade. These unique pharmacological properties of CTX-8371 could explain the enhanced T cell responses to tumor antigens and superior efficacy over current monoclonal antibody therapies. With favorable PK/PD and toxicology profiles in mice and cynomolgus monkeys, CTX-8371 warrants further advancement to clinical testing.

Experimental silicosis: a shift to a preferential IFN-γ-based Th1 response in thoracic lymph nodes

2000 ◽  
Vol 278 (6) ◽  
pp. L1221-L1230 ◽  
Author(s):  
Holger Garn ◽  
Anke Friedetzky ◽  
Andrea Kirchner ◽  
Ruth Jäger ◽  
Diethard Gemsa
Keyword(s):  
T Cell ◽  
Lymph Nodes ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytotoxic T Cell ◽  
Mrna Levels ◽  
Ifn Γ

In chronic silicosis, mechanisms leading to lymphocyte activation are still poorly understood, although it is well known that not only the lung but also the draining lymph nodes are affected. In the present study, we investigated T-cell activation by analysis of cytokine expression in the enlarged thoracic lymph nodes of rats 2 mo after an 8-day silica aerosol exposure. In the case of helper T cell (Th) type 1 cytokines, we found a significant increase in interferon (IFN)-γ mRNA expression, whereas interleukin (IL)-2 expression remained unchanged. In contrast, gene transcription for the Th2-type cytokines IL-4 and IL-10 was diminished. In addition, with use of an in vitro lymphocyte-macrophage coculture system, an enhanced IFN-γ and a reduced IL-10 release were shown with cells from silicotic animals. With regard to IFN-γ-inducing cytokines, we observed enhanced IL-12 mRNA levels in vivo, whereas IL-18 gene expression was slightly decreased. These data indicate that a persistent shift toward an IFN-γ-dominated type 1 (Th1/cytotoxic T cell type 1) T-cell reaction pattern occurred within the thoracic lymph nodes of silicotic animals. Thus a mutual activation of lymphocytes and macrophages may maintain the chronic inflammatory changes that characterize silicosis.

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.

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