scholarly journals Increased intracellular Ca2+ induces Ca2+ influx in human T lymphocytes.

1993 ◽  
Vol 4 (2) ◽  
pp. 173-184 ◽  
Author(s):  
D M Haverstick ◽  
L S Gray
Keyword(s):  
Intracellular Concentration ◽  
Jurkat Cells ◽  
Tumor Promoter ◽  
Excitable Cells ◽  
Entry Pathway ◽  
Internal Storage ◽  
Human T Lymphocyte ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line ◽  
Stimulation Of

One current hypothesis for the initiation of Ca2+ entry into nonelectrically excitable cells proposes that Ca2+ entry is linked to the state of filling of intracellular Ca2+ stores. In the human T lymphocyte cell line Jurkat, stimulation of the antigen receptor leads to release of Ca2+ from internal stores and influx of extracellular Ca2+. Similarly, treatment of Jurkat cells with the tumor promoter thapsigargin induced release of Ca2+ from internal stores and also resulted in influx of extracellular Ca2+. Initiation of Ca2+ entry by thapsigargin was blocked by chelation of Ca2+ released from the internal storage pool. The Ca2+ entry pathway also could be initiated by an increase in the intracellular concentration of Ca2+ after photolysis of the Ca(2+)-cage, nitr-5. Thus, three separate treatments that caused an increase in the intracellular concentration of Ca2+ initiated Ca2+ influx in Jurkat cells. In all cases, Ca(2+)-initiated Ca2+ influx was blocked by treatment with any of three phenothiazines or W-7, suggesting that it is mediated by calmodulin. These data suggest that release of Ca2+ from internal stores is not linked capacitatively to Ca2+ entry but that initiation is linked instead by Ca2+ itself, perhaps via calmodulin.

Apoptosis in human Jurkat T cells after culture with live Taenia crassiceps cysticerci in vitro

Parasitology ◽  
2000 ◽  
Vol 120 (6) ◽  
pp. 649-655 ◽  
Author(s):  
K. M. O'CONNELL ◽  
M. T. ROGAN
Keyword(s):  
Jurkat Cells ◽  
Apoptotic Bodies ◽  
Taenia Crassiceps ◽  
Single Cell Gel Electrophoresis ◽  
Human T Lymphocyte ◽  
Veterinary Importance ◽  
Induced Apoptosis ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line

This study examines the effects of Taenia crassiceps cysticerci on the viability of a human T lymphocyte cell line (Jurkat). Both budding and non-budding T. crassiceps metacestodes were cultured over 24 and 48 h in the presence of Jurkat cells. Cell viability decreased with increasing numbers of cysticerci, particularly budding cysticerci. Single cell gel electrophoresis (comet) analysis, which grades DNA damage, showed a significant increase in apoptosis at 24 and 48 h. The morphology of treated cells was determined using acridine orange with the classical morphology of apoptotic bodies seen to increase with increasing cysticerci numbers over time. These results indicate that parasite-induced apoptosis occurs during murine cysticercosis. Such a mechanism may be important in survival of other metacestode infections of medical or veterinary importance.

scholarly journals Calmidazolium and arachidonate activate a calcium entry pathway that is distinct from store-operated calcium influx in HeLa cells

2004 ◽  
Vol 381 (3) ◽  
pp. 929-939 ◽  
Author(s):  
Claire M. PEPPIATT ◽  
Anthony M. HOLMES ◽  
Jeong T. SEO ◽  
Martin D. BOOTMAN ◽  
Tony J. COLLINS ◽  
...  
Keyword(s):  
Hela Cells ◽  
Calcium Influx ◽  
Differential Sensitivity ◽  
Excitable Cells ◽  
Hormonal Stimulation ◽  
Calmodulin Antagonist ◽  
Alternative Pathways ◽  
Entry Pathway ◽  
Store Depletion ◽  
Stimulation Of

Agonists that deplete intracellular Ca2+ stores also activate Ca2+ entry, although the mechanism by which store release and Ca2+ influx are linked is unclear. A potential mechanism involves ‘store-operated channels’ that respond to depletion of the intracellular Ca2+ pool. Although SOCE (store-operated Ca2+ entry) has been considered to be the principal route for Ca2+ entry during hormonal stimulation of non-electrically excitable cells, recent evidence has suggested that alternative pathways activated by metabolites such as arachidonic acid are responsible for physiological Ca2+ influx. It is not clear whether such messenger-activated pathways exist in all cells, whether they are truly distinct from SOCE and which metabolites are involved. In the present study, we demonstrate that HeLa cells express two pharmacologically and mechanistically distinct Ca2+ entry pathways. One is the ubiquitous SOCE route and the other is an arachidonate-sensitive non-SOCE. We show that both these Ca2+ entry pathways can provide long-lasting Ca2+ elevations, but that the channels are not the same, based on their differential sensitivity to 2-aminoethoxydiphenyl borate, LOE-908 {(R,S)-(3,4-dihydro-6,7-dimethoxy-isochinolin-1-yl)-2-phenyl-N,N-di[2-(2,3,4-trimethoxyphenyl)ethyl]acetamid mesylate} and gadolinium. In addition, non-SOCE and not SOCE was permeable to strontium. Furthermore, unlike SOCE, the non-SOCE pathway did not require store depletion and was not sensitive to displacement of the endoplasmic reticulum from the plasma membrane using jasplakinolide or ionomycin pretreatment. These pathways did not conduct Ca2+ simultaneously due to the dominant effect of arachidonate, which rapidly curtails SOCE and promotes Ca2+ influx via non-SOCE. Although non-SOCE could be activated by exogenous application of arachidonate, the most robust method for stimulation of this pathway was application of the widely used calmodulin antagonist calmidazolium, due to its ability to activate phospholipase A2.

scholarly journals 1 alpha,25-Dihydroxy-20-epi-vitamin D3: an extraordinarily potent inhibitor of leukemic cell growth in vitro

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1960-1967
Author(s):  
E Elstner ◽  
YY Lee ◽  
M Hashiya ◽  
S Pakkala ◽  
L Binderup ◽  
...  
Keyword(s):  
Reporter Gene ◽  
T Lymphocyte ◽  
Vitamin D3 ◽  
Clonal Growth ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Colony Forming Unit ◽  
Human T Lymphocyte ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line

We have evaluated seven recently synthesized vitamin D3 analogs for their abilities to inhibit clonal growth of leukemic cells, to induce leukemic cell differentiation, to stimulate clonal growth of normal myeloid committed stem cells, and to transactivate a reporter gene having a 1,25(OH)2D3 response element (VDRE). The 1,25(OH)2–20-epi-D3 showed extraordinary activity; at 10(-11) mol/L it inhibited clonal growth of 87% of HL-60 myeloblast cells, 60% of S-LB1 cells (human T- cell lymphotropic virus type 1 [HTLV-1]-immortalized human T-lymphocyte cell line) and 50% of leukemic clonogenic cells (colony-forming unit- leukemia) obtained from patients with acute myelogenous leukemia. No effect of either 1,25(OH)2D3 or 1,25(OH)2–20-epi-D3 was observed on the clonal proliferation of an HTLV-1-immortalized human T-lymphocyte cell line (Ab-VDR) having nonfunctional 1,25 (OH)2D3 cellular receptors (VDR). The abilities of 1,25(OH)2–20-epi-D3 to induce differentiation of HL-60 cells, as measured by generation of superoxide and nonspecific esterase production, was less than its antiproliferative activities. This analog stimulated colony-forming unit-granulocyte-macrophage growth from normal human bone marrow. To gain insights into the remarkable antileukemic activities of 1,25(OH)2–20-epi-D3, we examined its ability to enter HL-60 cells, bind to the VDR, and interact with a transfected VDRE attached upstream of a TK promoter-driven reporter gene (chloramphenicol acetyl transferase [CAT]). The 1,25(OH)2–20-epi- D3 potently increased CAT activity (> 16-fold, as compared with cells transfected with control receptor having no VDRE); paradoxically, 1,25(OH)2–20-epi-D3 was of equal potency to 1,25(OH)2D3 in transactivating the VDRE-containing reporter gene, even though the analog had a 1,000-fold greater antileukemic effect as compared with 1,25(OH)2D3. In summary, we have identified an extremely potent 1,25(OH)2D3 analog with antiproliferative and differentiating effects on leukemic cells and that may be clinically useful. This analog appears to generate biologic responses via the classical VDR pathway, but further studies are required to elucidate the mechanism by which this analog produces its prominent activities.

scholarly journals Human T lymphocyte cell line producing colony-stimulating activity

Blood ◽  
1978 ◽  
Vol 52 (5) ◽  
pp. 1068-1072 ◽  
Author(s):  
DW Golde ◽  
SG Quan ◽  
MJ Cline
Keyword(s):  
Bone Marrow ◽  
Cell Line ◽  
T Lymphocyte ◽  
Maximal Activity ◽  
Blood Leukocytes ◽  
Murine Bone Marrow ◽  
Colony Stimulating Activity ◽  
Human T Lymphocyte ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line

Abstract We derived a permanent human T lymphocyte cell line that elaborates a potent colony-stimulating activity (CSA). The line was established with spleen cells from a patient with a T lymphocyte variant of hairy-cell leukemia. These cells form rosettes with sheep erythrocytes, show a proliferative response to phytohemagglutinin, and are lysed by antithymocyte globulin. They do not synthesize immunoglobulin, nor do they contain Epstein-Barr virus. CSA is regularly detected in the supernatant medium after 3 days culture. In the presence of PHA there is augmented elaboration of CSA; maximal activity is reached by 2 days and is 20% greater than that produced by a feeder layer of 1 X 10(6) peripheral blood leukocytes. One microliter of the supernatant material stimulated colony formation from the light-density nonadherent fraction of human bone marrow; there was maximal activity between 10 and 50 microliter/ml. Conditioned medium from these cells has little effect in stimulating CFU-C from murine bone marrow. The availability of a human T lymphocyte line producing CSA will provide a source for large quantities of the lymphocyte-derived hormone and permit a definition of factors modulating the interaction of T lymphocytes with granulocyte and monocyte stem cells.

scholarly journals 1 alpha,25-Dihydroxy-20-epi-vitamin D3: an extraordinarily potent inhibitor of leukemic cell growth in vitro

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1960-1967 ◽  
Author(s):  
E Elstner ◽  
YY Lee ◽  
M Hashiya ◽  
S Pakkala ◽  
L Binderup ◽  
...  
Keyword(s):  
Reporter Gene ◽  
T Lymphocyte ◽  
Vitamin D3 ◽  
Clonal Growth ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Colony Forming Unit ◽  
Human T Lymphocyte ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line

Abstract We have evaluated seven recently synthesized vitamin D3 analogs for their abilities to inhibit clonal growth of leukemic cells, to induce leukemic cell differentiation, to stimulate clonal growth of normal myeloid committed stem cells, and to transactivate a reporter gene having a 1,25(OH)2D3 response element (VDRE). The 1,25(OH)2–20-epi-D3 showed extraordinary activity; at 10(-11) mol/L it inhibited clonal growth of 87% of HL-60 myeloblast cells, 60% of S-LB1 cells (human T- cell lymphotropic virus type 1 [HTLV-1]-immortalized human T-lymphocyte cell line) and 50% of leukemic clonogenic cells (colony-forming unit- leukemia) obtained from patients with acute myelogenous leukemia. No effect of either 1,25(OH)2D3 or 1,25(OH)2–20-epi-D3 was observed on the clonal proliferation of an HTLV-1-immortalized human T-lymphocyte cell line (Ab-VDR) having nonfunctional 1,25 (OH)2D3 cellular receptors (VDR). The abilities of 1,25(OH)2–20-epi-D3 to induce differentiation of HL-60 cells, as measured by generation of superoxide and nonspecific esterase production, was less than its antiproliferative activities. This analog stimulated colony-forming unit-granulocyte-macrophage growth from normal human bone marrow. To gain insights into the remarkable antileukemic activities of 1,25(OH)2–20-epi-D3, we examined its ability to enter HL-60 cells, bind to the VDR, and interact with a transfected VDRE attached upstream of a TK promoter-driven reporter gene (chloramphenicol acetyl transferase [CAT]). The 1,25(OH)2–20-epi- D3 potently increased CAT activity (> 16-fold, as compared with cells transfected with control receptor having no VDRE); paradoxically, 1,25(OH)2–20-epi-D3 was of equal potency to 1,25(OH)2D3 in transactivating the VDRE-containing reporter gene, even though the analog had a 1,000-fold greater antileukemic effect as compared with 1,25(OH)2D3. In summary, we have identified an extremely potent 1,25(OH)2D3 analog with antiproliferative and differentiating effects on leukemic cells and that may be clinically useful. This analog appears to generate biologic responses via the classical VDR pathway, but further studies are required to elucidate the mechanism by which this analog produces its prominent activities.

Immunomodulating effects of water-soluble extracts of traditional French Alps cheeses on a human T-lymphocyte cell line

2006 ◽  
Vol 16 (12) ◽  
pp. 1505-1514 ◽  
Author(s):  
Christèle Durrieu ◽  
Pascal Degraeve ◽  
Stéphane Chappaz ◽  
Adèle Martial-Gros
Keyword(s):  
Cell Line ◽  
T Lymphocyte ◽  
Water Soluble ◽  
French Alps ◽  
Human T Lymphocyte ◽  
Lymphocyte Cell ◽  
Lymphocyte Cell Line
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