Search results for "Jurkat"
showing 10 items of 90 documents
Myeloid-Derived Suppressor Cells Specifically Suppress IFN-γ Production and Antitumor Cytotoxic Activity of Vδ2 T Cells.
2018
γδ T cells represent less than 5% of circulating T cells; they exert a potent cytotoxic function against tumor or infected cells and secrete cytokines like conventional αβ T cells. As αβ T cells γδ T cells reside in the typical T cell compartments (the lymph nodes and spleen), but are more widely distributed in tissues throughout the body. For these reasons, some investigators are exploring the possibility of immunotherapies aimed to expand and activate Vδ2 T cells, or using them as Chimeric Antigen Receptor carriers. However, the role of immunosuppressive microenvironment on Vδ2 T cells during infections and cancers has not been completely elucidated. In particular, the effects of myeloid-…
Thapsigargin-stimulated MAP kinase phosphorylation via CRAC channels and PLD activation: inhibitory action of docosahexaenoic acid.
2004
AbstractThis study was conducted on human Jurkat T-cells to investigate the role of depletion of intracellular Ca2+ stores in the phosphorylation of two mitogen-activated protein kinases (MAPKs), i.e. extracellular signal-regulated kinase (ERK) 1 and ERK2, and their modulation by a polyunsaturated fatty acid, docosahexaenoic acid (DHA). We observed that thapsigargin (TG) stimulated MAPK activation by store-operated calcium (SOC) influx via opening of calcium release-activated calcium (CRAC) channels as tyrphostin-A9, a CRAC channel blocker, and two SOC influx inhibitors, econazole and SKF-96365, diminished the action of the former. TG-stimulated ERK1/ERK2 phosphorylation was also diminished…
Isolactarane and Sterpurane Sesquiterpenoids from the Basidiomycete Phlebia uda
2012
Three new sesquiterpenoids, named udasterpurenol A, udalactarane A, and udalactarane B, as well as the known compounds hyphodontal and sterpuric acid have been isolated from the basidiomycete Phlebia uda. These compounds represent the first natural products described from this species. The structures were elucidated by NMR spectroscopy and mass spectrometry. Udalactaranes A and B were isolated as mixtures with their respective epimeric acetals. These mixtures inhibited the spore germination of the plant pathogenic fungus Fusarium graminearum at 10 and 5 μg/mL, respectively, and were active against Jurkat cells with IC(50) values of 101 and 42 μM, respectively.
N-(2-methyl-indol-1H-5-yl)-1-naphthalenesulfonamide : a novel reversible antimitotic agent inhibiting cancer cell motility
2016
Este es el post-print que se ha publicado de forma definitiva en: https://www.sciencedirect.com/science/article/abs/pii/S0006295216301423 A series of compounds containing the sulfonamide scaffold were synthesized and screened for their in vitro anticancer activity against a representative panel of human cancer cell lines, leading to the identification of N-(2-methyl-1H-indol-5-yl)-1-naphthalenesulfonamide (8e) as a compound showing a remarkable activity across the panel, with IC50 values in the nanomolar-to-low micromolar range. Cell cycle distribution analysis revealed that 8e promoted a severe G2/M arrest, which was followed by cellular senescence as indicated by the detection of senescen…
Constitutive and inducible protein/DNA interactions of the interferon-γ promoter inin vivo CD45RA and CD45RO T helper subsets
1997
Interferon-gamma (IFN-gamma) is a key cytokine of T lymphocytes with major regulatory functions in the immune system. To determine and compare protein/DNA interactions at the native IFN-gamma locus in T cells, we analyzed the human IFN-gamma promoter by ligation-mediated polymerase chain reaction (LM-PCR) techniques. Accordingly, Jurkat T cells and primary CD45RA and CD45R0 CD4+ T cell subsets isolated from peripheral blood using immunomagnetic beads were cultured and analyzed by LM-PCR. Constitutive and inducible protein/DNA interactions of the IFN-gamma promoter in vivo were detected in all T cells tested. Interestingly, an inducible footprint between -183 and -196 was consistently observ…
The Extracellular δ-Domain is Essential for the Formation of CD81 Tetraspanin Webs
2014
AbstractCD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes. Surprisingly, we find that large CD81 platforms assemble via the short extracellular δ-domain, independent from a strong primary partner binding and from weak interactions mediated by palmitoylation. The δ-domain is also essential for the platforms to function during viral entry. We propose that, ins…
A role for TASK2 channels in the human immunological synapse.
2020
The immunological synapse is a transient junction that occurs when the plasma membrane of a T cell comes in close contact with an APC after recognizing a peptide from the antigen-MHC. The interaction starts when CRAC channels embedded in the T cell membrane open, flowing calcium ions into the cell. To counterbalance the ion influx and subsequent depolarization, Kv 1.3 and KCa3.1 channels are recruited to the immunological synapse, increasing the extracellular K+ concentration. These processes are crucial as they initiate gene expression that drives T cell activation and proliferation. The T cell-specific function of the K2P channel family member TASK2 channels and their role in autoimmune p…
Interferon-α Abrogates the Suppressive Effect of Apoptotic Cells on Dendritic Cells in anIn VitroModel of Systemic Lupus Erythematosus Pathogenesis
2013
Objective.An increased incidence of apoptotic cells and an increased activation of dendritic cells (DC) may be involved in the pathogenesis of systemic lupus erythematosus (SLE). We investigated the characteristics of apoptotic neutrophils and monocyte-derived DC of patients with SLE, their interaction, and the influence of autoantibodies and inflammatory cytokines on this interaction.Methods.Kinetics of neutrophil apoptosis and DC activation were studied by flow cytometry. To analyze the interaction of apoptotic cells with phagocytes, crossover coculture experiments were performed with DC from patients with SLE and apoptotic Jurkat T cells as well as with apoptotic neutrophils from patient…
New Acylated Triterpene Saponins from Silene fortunei that Modulate Lymphocyte Proliferation
2002
Three new acylated triterpene saponins 1-3, with a quillaic acid as aglycon, were isolated from the roots of Silene fortunei together with a known phytoecdysteroid (20-hydroxyecdysone). The compounds were characterized mainly by a combination of 2D NMR techniques, mass spectrometry, and chemical methods. Saponins 1-3, jenisseensosides C and D (4, 5), and 6 (deacylated form of 2/3 and 4/5) were found to stimulate the proliferation of the Jurkat tumor cell lines at low concentration. At high concentration, 2/3 and 4/5 inhibited the proliferation of the cells and suggested the induction of apoptosis.
The actin remodeling protein cofilin is crucial for thymic αβ but not γδ T-cell development
2018
Cofilin is an essential actin remodeling protein promoting depolymerization and severing of actin filaments. To address the relevance of cofilin for the development and function of T cells in vivo, we generated knock-in mice in which T-cell–specific nonfunctional (nf) cofilin was expressed instead of wild-type (WT) cofilin. Nf cofilin mice lacked peripheral αβ T cells and showed a severe thymus atrophy. This was caused by an early developmental arrest of thymocytes at the double negative (DN) stage. Importantly, even though DN thymocytes expressed the TCRβ chain intracellularly, they completely lacked TCRβ surface expression. In contrast, nf cofilin mice possessed normal numbers of γδ T cel…