Search results for "Jurkat"
showing 10 items of 90 documents
Immunotoxicological in vitro effects of BEA and ENN B on Jurkat cell line
2016
CD38 expression enhances sensitivity of lymphoma T and B cell lines to biochemical and receptor-mediated apoptosis
2006
CD38 has been widely characterised both as an ectoenzyme and as a receptor. In the present paper, we investigated the role of CD38 as possible modulator of apoptosis. CD38-positive (CD38(+)) and negative (CD38(-)) fractions, obtained by sorting CD38(+) cells from lymphoma T (Jurkat) and lymphoma B (Raji) and by transfecting lymphoma LG14 and myeloid leukemia K562 cell lines, were used. Cellular subpopulations were exposed to different triggers (H(2)O(2), UV-B, alpha-TOS and hrTRAIL) and the extent of apoptosis was determined by Annexin V-FITC/PI assay. Our data showed that, in lymphoma cells, propensity to apoptosis was significantly linked to CD38 expression and that, remarkably, such resp…
Diacylglycerol-containing oleic acid induces increases in [Ca(2+)](i) via TRPC3/6 channels in human T-cells.
2011
Though most of the studies have focused on the effects of free fatty acids on T-cell activation, fatty acids incorporated into plasma membrane phospholipids may also affect cell signaling via diacylglycerol (DAG), generally produced by phospholipid hydrolysis. In the present study, we have synthesized a DAG-containing oleic acid and studied its implication in the modulation of calcium signaling in human Jurkat T-cells. 1-palmitoyl-2-oleoyl-sn-glycerol (POG) induced a dose-dependent increase in [Ca(2+)](i). This effect was due to the presence of oleic acid at the sn-2 position as no differences were observed between POG and 1-stearoly-2-oleoyl-sn-glycerol (SOG). However, the substitution of …
APOBEC4 Enhances the Replication of HIV-1
2016
APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral L…
2004
T-cell receptor transfer into human T cells with ecotropic retroviral vectors
2014
Adoptive T-cell transfer for cancer immunotherapy requires genetic modification of T cells with recombinant T-cell receptors (TCRs). Amphotropic retroviral vectors (RVs) used for TCR transduction for this purpose are considered safe in principle. Despite this, TCR-coding and packaging vectors could theoretically recombine to produce replication competent vectors (RCVs), and transduced T-cell preparations must be proven free of RCV. To eliminate the need for RCV testing, we transduced human T cells with ecotropic RVs so potential RCV would be non-infectious for human cells. We show that transfection of synthetic messenger RNA encoding murine cationic amino-acid transporter 1 (mCAT-1), the re…
Leaf and Root Extracts from Campomanesia adamantium (Myrtaceae) Promote Apoptotic Death of Leukemic Cells via Activation of Intracellular Calcium and…
2017
Phytochemical studies are seeking new alternatives to prevent or treat cancer, including different types of leukemias. Campomanesia adamantium, commonly known as guavira or guabiroba, exhibits pharmacological properties including antioxidant, antimicrobial, and antiproliferative activities. Considering the anticancer potential of this plant species, the aim of this study was to evaluate the antileukemic activity and the chemical composition of aqueous extracts from the leaves (AECL) and roots (AECR) of C. adamantium and their possible mechanisms of action. The extracts were analyzed by LC-DAD-MS, and their constituents were identified based on the UV, MS, and MS/MS data. The AECL and AECR s…
Beauvericin and enniatin B effects on a human lymphoblastoid Jurkat T-cell model
2018
Abstract Several mycotoxins exert their effect on the immunological system; some are classified as immunotoxic. Jurkat T-cells were used to study toxic effects of beauvericin (BEA) and enniatin B (ENN B). Both are not legislated mycotoxins with increasing presence in feed and food. Concentrations studied were from 1 to 15 μM at 24, 48 and 72 h. Cell death by increasing the percentage of apoptotic/necrotic cells was: BEA > ENN B. IC50 values ranged from 3 to 7.5 μM for BEA. ENN B 15 μM decreased viability (21-29%). The percentage of apoptotic/necrotic cells was BEA > ENN B at 24 h but not at 48 h. Caspase-3&7 activation profile varied, although both mycotoxins increased this activation. No d…
Modulation of intracellular calcium concentrations and T cell activation by prickly pear polyphenols.
2004
Opuntia ficus indica (prickly pear) polyphenolic compounds (OFPC) triggered an increase in [Ca2+]i in human Jurkat T-cell lines. Furthermore, OFPC-induced rise in [Ca2+]i was significantly curtailed in calcium-free buffer (0% Ca2+) as compared to that in 100% Ca2+ medium. Preincubation of cells with tyrphostin A9, an inhibitor of Ca2+ release-activated Ca2+ (CRAC) channels, significantly diminished the OFPC-induced sustained response on the increases in [Ca2+]i. Lanthanum and nifedipine, the respective inhibitors of voltage-dependent and L-type calcium channels, failed to curtail significantly the OFPC-induced calcium response. As OFPC still stimulated increases in [Ca2+]i in 0% Ca2+ medium…
Pyrrolo[3,2-h]quinazolines as Photochemotherapeutic Agents
2011
Heteroanalogues of angelicin, pyrrolo[3,2-h]quinazolines, were synthesized with the aim of obtaining new potent photochemotherapeutic agents. Many derivatives caused a significant decrease in cell proliferation in several human tumor cell lines after irradiation with UVA light (GI(50) =15.2-0.2 μM). Their phototoxicity effected apoptosis in Jurkat cells with the involvement of mitochondria (as determined by the loss of mitochondrial membrane potential and production of reactive oxygen species) and lysosomes. The phototoxicity of these compounds could be explained by lipid peroxidation.