Platelet-activating factor synergizes with phorbol myristate acetate in activating phospholipase D in the human promonocytic cell line U937. Evidence for different mechanisms of activation.

Balsinde, Jesús; Mollinedo, Faustino

doi:10.1016/s0021-9258(18)55123-1

Cited by 35 publications

(6 citation statements)

References 51 publications

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“…On the other hand, Kp43-induced phospholipase D activation occurs in the absence of polyphosphoinositide turnover and does not depend on external Ca 2+ . Altogether, these results give further support to the notion that different pathways exist for activation of phospholipase D (14,20,22,37). Moreover, this study has documented for the first time the existence of two distinct receptor-modulated pathways for phospholipase D activation within the same cell type.…”

Section: Discussionsupporting

confidence: 86%

“…1). PMA has been previously shown to optimally activate phospholipase D in human leukocytes (14,(21)(22)(23). Thin-layer chromatography analyses of lipid extracts derived from PMAstimulated NK cells exposed to ethanol revealed the presence of a unique spot (Fig.…”

Section: Resultsmentioning

confidence: 92%

“…For 32p labeling, cells were incubated overnight with 20/~Ci/ml H3132p]o4. Appropriately labded cells were resuspended in HG buffer (150 mM NaC1, 1.2 mM MgC12, 1.3 mM CaC12, 5.5 mM n-glucose, 10 mM Hepes, pH 7.5) to a concentration of 107 cells/mE The reactions were initiated by adding either vehicle or the corresponding stimulus, in the presence or absence of 0.5% ethanol Reactions were stopped by adding an equal volume of chloroform/methanol/hydrochloric acid (100:200:1) and lipids were extracted as described (14).…”

Section: Methodsmentioning

confidence: 99%

“…Ca 2+ has been proposed to be a key regulator ofphospholipase D activity in human HL60 granulocytes (21,24), human U937 promonocytes (14), and human erythroleukemia cells and platelets (25,26). Therefore, we examined the involvement of Ca ~+ in IL-2-treated NK cell phospholipase D activation.…”

Section: Role Of Ca 2+ In Receptor Stimulation Of Phospholipase D In Il2-treated Nk Cellsmentioning

confidence: 99%

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Phospholipase D activation in human natural killer cells through the Kp43 and CD16 surface antigens takes place by different mechanisms. Involvement of the phospholipase D pathway in tumor necrosis factor alpha synthesis.

Balboa

Balsinde

Aramburu

et al. 1992

The Journal of Experimental Medicine

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SummaryWe have recently described a novel glycoprotein, Kp43, expressed on the surface of human natural killer (NK) cells that appears to regulate their functional activity. In this report, signaling mechanisms through the Kp43 surface antigen have been studied. Incubation of interleukin 2 (IL-2)-treated NK cells with anti-Kp43 monoclonal antibody F(ab')2 fragments resulted in the time-and dosedependent stimulation of NK cell phospholipase D. Phospholipase D activation through the Kp43 surface antigen was found to take place in the absence of polyphosphoinositide turnover and appeared not to depend on the presence of Ca 2 + in the extracellular medium. On the other hand, signaling mechanisms through the CD16 receptor (FcR-III) on NK cells were comparatively studied. Stimulation of IL-2-treated NK cells with anti-CD16 monoclonal antibody F(ab')2 fragment also resulted in time-and dose-dependent activation of phospholipase D. However, CD16-triggered phospholipase D activation took place concomitant to phospholipase C-mediated polyphosphoinositide breakdown and showed a strong dependence on extracellular Ca 2+ . These results provide, to our knowledge, the first evidence for the presence of activatable phospholipase D in NK cells, as well as the first indication that distinct receptor-modulated pathways exist for activation of phospholipase D within the same cell type. On the other hand, phosphatidic acid, the physiologic product of phospholipase D action on phospholipids, was found to mimic the effect of anti-Kp43 monoclonal antibody regarding tumor necrosis factor o~ (TNF-ol) biosynthesis and secretion by NK cells. Addition of phosphatidic acid vesicles to Ib2-treated NK cell cultures stimulated a TNF-ol production that was abolished when the cells were previously treated with actinomycin D. Other phospholipids, including lysophosphatidic acid, were ineffective. However, phosphatidic acid-induced TNF-c~ production was strongly inhibited by the presence of propranolol, an inhibitor of phosphatidic acid phosphohydrolase. Moreover, in cells responding to phorbol myristate acetate, a compound that triggers activation of phospholipase D, TNF-c~ synthesis was also inhibited by propranolol. Thus, these data suggest a second messenger role for phosphatidic acid-derived diradylglycerol in the induction of TNF-c~ gene expression.

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Section: Discussionsupporting

confidence: 86%

Section: Resultsmentioning

confidence: 92%

Section: Methodsmentioning

confidence: 99%

Section: Role Of Ca 2+ In Receptor Stimulation Of Phospholipase D In Il2-treated Nk Cellsmentioning

confidence: 99%

See 2 more Smart Citations

Phospholipase D activation in human natural killer cells through the Kp43 and CD16 surface antigens takes place by different mechanisms. Involvement of the phospholipase D pathway in tumor necrosis factor alpha synthesis.

Balboa

Balsinde

Aramburu

et al. 1992

The Journal of Experimental Medicine

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“…This suggested that GTP[S] promoted the membrane localization of a PLD activity which was independent of added cytosol. The elevated PLD activity of membranes isolated from cells pretreated with GTP[S] persisted following repeated washings and storage at 4 °C for 48 h. Vanadate and PMA potently activate PLD in U937 cells and other phagocytic leucocytes [10,26,27,[36][37][38][39][40]. However, in contrast with the effects of GTP[S], treatment of permeabilized U937 cells with vanadate or of intact cells with PMA did not result in a cytosol-independent PLD activity in subsequently isolated membranes (results not shown).…”

Section: Gtp[s] Treatment Of Permeabilized U937 Cells Resultsmentioning

confidence: 97%

Guanosine 5′-[γ-thio]triphosphate induces membrane localization of cytosol-independent phospholipase D activity in a cell-free system from U937 promonocytic leucocytes

Kusner

Dubyak

1994

Biochemical Journal

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Activation of phospholipase D (PLD) in phagocytic leucocytes requires protein components present in both the plasma membrane and the cytosol, but the catalytic and regulatory factors are not fully defined. We have characterized the effect of guanosine 5'-[gamma-thio]triphosphate (GTP[S]) on the subcellular requirements for reconstitution of PLD activity, using a cell-free system from U937 human promonocytic leucocytes. Incubation of permeabilized cells with 100 microM GTP[S] resulted in a membrane-localized PLD activity which was independent of added cytosol. The PLD activity of membranes from GTP[S]-treated cells was 7-fold greater than the basal activity of control membranes, and could be further augmented by the addition of ATP. This was the first demonstration of a stable agonist-regulated PLD activity in membranes from phagocytic leucocytes which was quantitatively comparable with that seen in a fully reconstituted system. Cytosol from GTP[S]-treated cells had a decreased capacity to support PLD activation, consistent with GTP[S]-induced depletion of a factor essential for reconstitution of PLD activity. Incubation of isolated membrane and cytosol with GTP[S] also resulted in a cytosol-independent PLD activity in the re-isolated membranes. The effect of GTP[S] could be mimicked by guanosine 5'-[beta gamma-imido]triphosphate, but not by aluminium fluoride, consistent with the involvement of a low-molecular-mass GTP-binding protein(s). Incubation of isolated subcellular fractions with GTP[S], followed by removal of unbound nucleotide, suggested that at least one of the GTP-binding proteins involved in the membrane localization of PLD activity was itself present in the membrane fraction. These data were consistent with a model in which activation of GTP-binding protein(s) resulted in the stable assembly of an active PLD signalling complex at the membrane surface.

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Wortmannin, an inhibitor of phospholipase D activation, selectively blocks major histocompatibility complex class II‐restricted antigen presentation

1994

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Wortmannin, a fungal metabolite, is a specific inhibitor of phospholipase D (PLD) activation. Presentation of defined exogenous soluble proteins to specific T cell hybridomas was studied by using different antigen-presenting cells (APC): IA-positive peritoneal macrophages (M phi), B lymphoma cells (B) or dendritic cells (DC). Major histocompatibility complex class II-restricted antigen presentation by M phi was blocked when cells were pretreated with wortmannin. However, when cells constitutively expressing IA molecules (B, DC) were used as APC, no inhibition was observed. Additionally, MHC class I antigen presentation was not impaired by wortmannin. Moreover, wortmannin does not block either peptide presentation or presentation to autoreactive T cells. This effect was time and dose dependent and occurred at the level of intracellular handling of the antigen. Mainly because it was not a toxic inhibition, it was reversible with time and neither antigen uptake and catabolism, nor IA synthesis were affected. Because M phi, but not B or DC, express PLD activity and only the former were blocked by wortmannin in antigen presentation, our results strongly suggest that a differential antigen-processing pathway exists in these disparate APC, which could be based essentially on a wortmannin-sensitive, PLD-dependent step present in M phi but absent and/or unnecessary in both B lymphoma cells and DC.

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Platelet-activating factor synergizes with phorbol myristate acetate in activating phospholipase D in the human promonocytic cell line U937. Evidence for different mechanisms of activation.

Cited by 35 publications

References 51 publications

Phospholipase D activation in human natural killer cells through the Kp43 and CD16 surface antigens takes place by different mechanisms. Involvement of the phospholipase D pathway in tumor necrosis factor alpha synthesis.

Phospholipase D activation in human natural killer cells through the Kp43 and CD16 surface antigens takes place by different mechanisms. Involvement of the phospholipase D pathway in tumor necrosis factor alpha synthesis.

Guanosine 5′-[γ-thio]triphosphate induces membrane localization of cytosol-independent phospholipase D activity in a cell-free system from U937 promonocytic leucocytes

Wortmannin, an inhibitor of phospholipase D activation, selectively blocks major histocompatibility complex class II‐restricted antigen presentation

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