scholarly journals Agonist-induced inhibition of phosphatidylserine synthesis is secondary to the emptying of intracellular Ca2+ stores in Jurkat T-cells

1992 ◽  
Vol 288 (3) ◽  
pp. 785-789 ◽  
Author(s):  
C Pelassy ◽  
J P Breittmayer ◽  
C Aussel
Keyword(s):  
T Cells ◽  
Exchange System ◽  
Jurkat T Cells ◽  
Experimental Conditions ◽  
Intact Cells ◽  
Base Exchange ◽  
Permeabilized Cells ◽  
Atpase Inhibitors ◽  
Storage Organelle ◽  
Intracellular Compartments

The biosynthesis of phosphatidylserine (PtdSer) by the serine base-exchange enzyme system, in Jurkat T-lymphocytes, was inhibited in intact cells maintained in low-Ca(2+)-containing buffer (< 10 microM-Ca2+) by using Ca2+ ionophores (A23187 or ionomycin). The rise in cytosolic Ca2+ concentration under these experimental conditions was only due to the release of Ca2+ from intracellular compartments, suggesting that the inhibition of PtdSer synthesis was correlated with the emptying of intracellular Ca2+ pools. This was further studied in saponin-permeabilized cells, in which PtdSer synthesis was found to be inhibited by EGTA, Ca2+ ionophores (A23187 or ionomycin) and Ca(2+)-ATPase inhibitors [thapsigargin or 2,5-di-(t-butyl)-benzohydroquinone]. Since Ca(2+)-ATPase inhibitors impaired refilling of the Ca2+ stores with Ca2+, and since in CD3-activated Jurkat T-cells the Ca2+ stores remained empty after 1 h of treatment with anti-CD3 monoclonal antibodies, we suggest that PtdSer synthesis is mainly regulated by the level of Ca2+ in the intracellular compartments and that the Ca(2+)-dependent serine base-exchange system responsible for PtdSer synthesis is probably located within or close to a Ca(2+)-storage organelle.

scholarly journals Two essential regulatory elements in the human interferon gamma promoter confer activation specific expression in T cells.

1993 ◽  
Vol 178 (5) ◽  
pp. 1483-1496 ◽  
Author(s):  
L Penix ◽  
W M Weaver ◽  
Y Pang ◽  
H A Young ◽  
C B Wilson
Keyword(s):  
T Cells ◽  
Interferon Gamma ◽  
Regulatory Elements ◽  
T Cell Subsets ◽  
Jurkat T Cells ◽  
Intact Cells ◽  
Ifn Gamma ◽  
Promoter Function ◽  
Gm Csf ◽  
Nuclear Extracts

Like interleukin 2 (IL-2), interferon gamma (IFN-gamma) is an early response gene in T cells and both are prototypical T helper cell type 1 (Th-1) lymphokines. Yet IL-2 and IFN-gamma production are independently regulated, as demonstrated by their differential expression in certain T cell subsets, suggesting that the regulatory elements in these two genes must differ. To explore this possibility, the 5' flank of the human IFN-gamma gene was analyzed. Expression of IFN-gamma promoter-driven beta-galactosidase reporter constructs containing 538 bp of 5' flank was similar to that by constructs driven by the IL-2 promoter in activated Jurkat T cells; expression nearly as great was observed with the construct containing only 108 bp of IFN-gamma 5' flank. These IFN-gamma promoter constructs faithfully mirrored expression of the endogenous gene, in that expression required activation both with ionomycin and PMA, was inhibited by cyclosporin A, and was not observed in U937 or THP-1 cells. The region between -108 and -40 bp in the IFN-gamma promoter was required for promoter function and contained two elements that are conserved across species. Deletion of 10 bp within either element reduced promoter function by 70%, whereas deletions in nonconserved portions of this region had little effect on promoter function. The distal conserved element (-96 to -80 bp) contained a consensus GATA motif and a potential regulatory motif found in the promoter regions of the GM-CSF and macrophage inflammatory protein (MIP) genes. Factors binding to this element, including GATA-3, were found in Jurkat nuclear extracts by electromobility shift assays and two of the three complexes observed were altered in response to activation. One or both of these motifs are present in the 5' flank of multiple, other lymphokine genes, including IL-3, IL-4, IL-5, and GM-CSF, but neither is present in the promoter of the IL-2 gene. The proximal conserved element (-73 to -48 bp) shares homology with the NFIL-2A element in the IL-2 promoter; these elements compete for binding of factors in Jurkat nuclear extracts, although the NFIL-2A element but not the IFN-gamma element binds Oct-1. Factors binding to this element in the IFN-gamma gene were present in extracts from resting and activated Jurkat T cells. However, by in vivo footprinting of intact cells, this element was protected from methylation only with activation.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Ca2+ release and Ca2+ entry induced by rapid cytosolic alkalinization in Jurkat T-lymphocytes

1994 ◽  
Vol 301 (1) ◽  
pp. 83-88 ◽  
Author(s):  
A H Guse ◽  
E Roth ◽  
F Emmrich
Keyword(s):  
T Cells ◽  
Intracellular Ph ◽  
Cell Receptor ◽  
K Channel ◽  
Cytosolic Ph ◽  
Intact Cells ◽  
Inositol Polyphosphates ◽  
Simultaneous Formation ◽  
Permeabilized Cells ◽  
Release System

4-Aminopyridine (4-AP), a compound usually known as a K(+)-channel inhibitor, induced rapid cytosolic alkalinization from pH 7.15 to pH 7.4, and subsequently Ca2+ mobilization in the T-lymphocyte cell line Jurkat. Other weak bases, such as NH4Cl or triethanolamine, induced a smaller and/or slower increase in cytosolic pH, resulting in a lower or no detectable Ca2+ signal. In the presence of extracellular Ca2+, 4-AP mediated a rapid and sustained increase in the free cytosolic Ca2+ concentration similar to that obtained by T-cell receptor-mediated stimulation. In the absence of extracellular Ca2+, 4-AP transiently released Ca2+ from an intracellular store that is most likely identical with the agonist- and Ins(1,4,5)P3-sensitive Ca2+ pool of Jurkat T-cells. As possible mechanisms for Ca2+ release from this particular pool as induced by 4-AP we examined (i) formation of Ins(1,4,5)P3 and (ii) sensitization of the Ins(1,4,5)P3-receptor/Ca(2+)release system by increasing intracellular pH. Although 4-AP did not induce formation of inositol polyphosphates, as demonstrated by h.p.l.c. analysis, in permeabilized cells the dose-response curve for Ins(1,4,5)P3 was shifted to the left by changing the intracellular pH from 7.2 to 7.4. This indicated that sensitization of the Ins(1,4,5)P3-receptor/Ca(2+)-release system was responsible for the effects of 4-AP seen in intact cells. In conclusion, 4-AP appears a novel tool for depletion of the agonist-sensitive Ca2+ pool of T-cells without simultaneous formation of Ins(1,4,5)P3, thereby inducing capacitative Ca2+ entry in these cells.

The protein tyrosine kinase p56lck regulates the serine-base exchange activity in Jurkat T cells

FEBS Letters ◽  
1997 ◽  
Vol 405 (2) ◽  
pp. 163-166 ◽  
Author(s):  
Rachid Marhaba ◽  
Marie-Jeanne Dumaurier ◽  
Claudette Pelassy ◽  
Michelle Batoz ◽  
Jean Francois Peyron ◽  
...  
Keyword(s):  
T Cells ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Jurkat T Cells ◽  
Base Exchange ◽  
Protein Tyrosine ◽  
Exchange Activity

The role of cbl family of ubiquitin ligases in gastric cancer exosome-induced apoptosis of Jurkat T cells

2009 ◽  
pp. 1-8
Author(s):  
Jing-Lei Qu ◽  
Xiu-Juan Qu ◽  
Ming-Fang Zhao ◽  
Yue-E Teng ◽  
Ye Zhang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
T Cells ◽  
Ubiquitin Ligases ◽  
Jurkat T Cells ◽  
Induced Apoptosis

scholarly journals Amorphous–Crystalline Calcium Phosphate Coating Promotes In Vitro Growth of Tumor-Derived Jurkat T Cells Activated by Anti-CD2/CD3/CD28 Antibodies

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3693
Author(s):  
Yurii P. Sharkeev ◽  
Ekaterina G. Komarova ◽  
Valentina V. Chebodaeva ◽  
Mariya B. Sedelnikova ◽  
Aleksandr M. Zakharenko ◽  
...  
Keyword(s):  
T Cells ◽  
Calcium Phosphate ◽  
Biological Effects ◽  
Electrical Potential ◽  
Biological Properties ◽  
Modern Trend ◽  
Calcium Phosphate Coating ◽  
Jurkat T Cells ◽  
Micro Arc Oxidation

A modern trend in traumatology, orthopedics, and implantology is the development of materials and coatings with an amorphous–crystalline structure that exhibits excellent biocopatibility. The structure and physico–chemical and biological properties of calcium phosphate (CaP) coatings deposited on Ti plates using the micro-arc oxidation (MAO) method under different voltages (200, 250, and 300 V) were studied. Amorphous, nanocrystalline, and microcrystalline statesof CaHPO4 and β-Ca2P2O7were observed in the coatings using TEM and XRD. The increase in MAO voltage resulted in augmentation of the surface roughness Ra from 2.5 to 6.5 µm, mass from 10 to 25 mg, thickness from 50 to 105 µm, and Ca/P ratio from 0.3 to 0.6. The electrical potential (EP) of the CaP coatings changed from −456 to −535 mV, while the zeta potential (ZP) decreased from −53 to −40 mV following an increase in the values of the MAO voltage. Numerous correlations of physical and chemical indices of CaP coatings were estimated. A decrease in the ZP magnitudes of CaP coatings deposited at 200–250 V was strongly associated with elevated hTERT expression in tumor-derived Jurkat T cells preliminarily activated with anti-CD2/CD3/CD28 antibodies and then contacted in vitro with CaP-coated samples for 14 days. In turn, in vitro survival of CD4+ subsets was enhanced, with proinflammatory cytokine secretion of activated Jurkat T cells. Thus, the applied MAO voltage allowed the regulation of the physicochemical properties of amorphous–crystalline CaP-coatings on Ti substrates to a certain extent. This method may be used as a technological mechanism to trigger the behavior of cells through contact with micro-arc CaP coatings. The possible role of negative ZP and Ca2+ as effectors of the biological effects of amorphous–crystalline CaP coatings is discussed. Micro-arc CaP coatings should be carefully tested to determine their suitability for use in patients with chronic lymphoid malignancies.

scholarly journals Semi-purified extracts of Commelina benghalensis (Commelinaceae) induce apoptosis and cell cycle arrest in Jurkat-T cells

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Kgomotso Welheminah Lebogo ◽  
Matlou Phineas Mokgotho ◽  
Victor Patrick Bagla ◽  
Thabe Moses Matsebatlela ◽  
Vusi Mbazima ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
Cell Cycle Arrest ◽  
Jurkat T Cells ◽  
Commelina Benghalensis ◽  
Cycle Arrest

Glycogen synthase kinase-3β is critical for Interferon-α-induced serotonin uptake in human Jurkat T cells

2012 ◽  
Vol 227 (6) ◽  
pp. 2556-2566 ◽  
Author(s):  
Chiung-Wen Tsao ◽  
Chiou-Feng Lin ◽  
Hung-Tsung Wu ◽  
Ching-Ting Ma ◽  
Wei-Ching Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Glycogen Synthase ◽  
Serotonin Uptake ◽  
Glycogen Synthase Kinase ◽  
Interferon Α ◽  
Glycogen Synthase Kinase 3Β ◽  
Jurkat T Cells
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