Adenosine cyclic 3',5'-monophosphate response to concanavalin A in human lymphocytes. Evidence that the response involves specific carbohydrate receptors on the cell surface

Biochemistry ◽  
1974 ◽  
Vol 13 (26) ◽  
pp. 5415-5420 ◽  
Author(s):  
Leon R. Lyle ◽  
Charles W. Parker
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Human Lymphocytes

scholarly journals TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Is Upregulated in Lymphocytes Stimulated with Concanavalin A

2021 ◽  
Vol 22 (14) ◽  
pp. 7436
Author(s):  
Helga Simon-Molas ◽  
Xavier Vallvé-Martínez ◽  
Irene Caldera-Quevedo ◽  
Pere Fontova ◽  
Claudia Arnedo-Pac ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Carbon Flux ◽  
Human Lymphocytes ◽  
Tumor Development ◽  
Pentose Phosphate ◽  
Akt Signaling Pathway ◽  
G6pdh Activity ◽  
Physiological Conditions ◽  
Glucose 6 Phosphate Dehydrogenase

The glycolytic modulator TP53-Inducible Glycolysis and Apoptosis Regulator (TIGAR) is overexpressed in several types of cancer and has a role in metabolic rewiring during tumor development. However, little is known about the role of this enzyme in proliferative tissues under physiological conditions. In the current work, we analysed the role of TIGAR in primary human lymphocytes stimulated with the mitotic agent Concanavalin A (ConA). We found that TIGAR expression was induced in stimulated lymphocytes through the PI3K/AKT pathway, since Akti-1/2 and LY294002 inhibitors prevented the upregulation of TIGAR in response to ConA. In addition, suppression of TIGAR expression by siRNA decreased the levels of the proliferative marker PCNA and increased cellular ROS levels. In this model, TIGAR was found to support the activity of glucose 6-phosphate dehydrogenase (G6PDH), the first enzyme of the pentose phosphate pathway (PPP), since the inhibition of TIGAR reduced G6PDH activity and increased autophagy. In conclusion, we demonstrate here that TIGAR is upregulated in stimulated human lymphocytes through the PI3K/AKT signaling pathway, which contributes to the redirection of the carbon flux to the PPP.

Perfluorocarbon attenuates response of concanavalin A-stimulated mononuclear blood cells without altering ligand-receptor interaction

2004 ◽  
Vol 287 (1) ◽  
pp. L210-L216 ◽  
Author(s):  
Dirk Haufe ◽  
Thomas Luther ◽  
Matthias Kotzsch ◽  
Lilla Knels ◽  
Thea Koch
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Blood Cells ◽  
Cell Activation ◽  
Receptor Interaction ◽  
Surface Binding ◽  
Cellular Activation ◽  
Flow Cytofluorometry ◽  
Anti Inflammatory ◽  
Mononuclear Blood Cells

Intrapulmonary application of perfluorocarbons (PFC) in acute lung injury is associated with anti-inflammatory effects. A direct impact on leukocytic function may be involved. To further elucidate PFC effects on cellular activation, we compared in an in vitro model the response of concanavalin A (ConA)-stimulated lymphocytes and monocytes exposed to perfluorohexane. We hypothesized that perfluorohexane attenuates the action of the lectin ConA by altering stimulant-receptor interaction on the cell surface. Mononuclear blood cells were stimulated by incubation with ConA in the presence of different amounts of perfluorohexane. The response of lymphocytes and monocytes was determined by means of IL-2 secretion and tissue factor (TF) expression, respectively. The influence of perfluorohexane on cell-surface binding of fluorescence-labeled ConA was studied using flow cytofluorometry and fluorescence microscopy. Perfluorohexane itself did not induce a cellular activation but significantly inhibited both monocytic TF expression and, to a far greater extent, IL-2 secretion of ConA-stimulated mononuclear blood cells. The effect of perfluorohexane was due neither to an alteration of cell viability nor to a binding of the stimulant. The amount of cell surface-bound ConA was not altered by perfluorohexane, and the overall pattern of ConA receptor rearrangement did not differ between controls and treated cells. In the present study, we provide further evidence for an anti-inflammatory effect of PFC that might be beneficial in states of pulmonary hyperinflammation. A PFC-induced alteration of stimulant-receptor interaction on the surface membrane does not seem to be the cause of attenuated cell activation.

Surface morphology and agglutination of lectin-treated human lymphocytes and lymphoblasts

1976 ◽  
Vol 21 (3) ◽  
pp. 563-578
Author(s):  
J.H. Temmink ◽  
J.G. Collard ◽  
J. Roosien ◽  
J.F. Van den Bosch
Keyword(s):  
Cell Surface ◽  
Surface Morphology ◽  
Human Lymphocytes ◽  
Cell Type ◽  
A Cell ◽  
Human Peripheral Lymphocytes ◽  
Normal Human ◽  
Altered Cell ◽  
Induced Changes ◽  
Cell Surface Morphology

Two human lymphoblasts (Raji and EB3) and normal human peripheral lymphocytes were exposed to different concentrations of Concanavalin A and wheat germ agglutinin. The lectin-induced agglutination was determined and correlated with lectin-induced changes in the surface morphology of these cells as studied in a scanning electron microscope. Whenever the lectin induced high agglutinability in a cell type, it also invariably had a smoothing effect on the cell surface. In contrast, when cells did not agglutinate well with a certain lectin, their cell surface remained essentially rough (villous) after addition of the lectin. The correlation found between increased agglutinability and altered cell surface morphology upon treatment with certain lectins suggests that both phenomena result from one and the same process. Additional evidence for this postulate is presented.

Changes in lectin-mediated agglutinability during primary embryonic induction in the amphibian embryo

Development ◽  
1980 ◽  
Vol 57 (1) ◽  
pp. 95-106
Author(s):  
Francisco D. Barbieri ◽  
Sara S. Sánchez ◽  
Enrique J. Del Pino
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Cytochalasin B ◽  
The Other ◽  
Embryonic Induction ◽  
Potassium Oxalate ◽  
Amphibian Embryo ◽  
Structural Alterations ◽  
Significant Difference ◽  
Primary Embryonic Induction

The present study was undertaken to investigate structural alterations at the surfaceof presumptive neural cells after primary embryonic induction. For this purpose, plant lectinmediated agglutinability of dissociated cells from the epiblast of Bufo arenarum gastrulae was tested. Two fragments of epiblast were excised from the same mid-gastrula: one from the dorsal side of the egg, making contact with the invaginating chordamesoblast and assumed to be composed of determined cells and the other from the ventral region of the egg, facing the blastocoele cavity and assumed to be composed of undetermined cells. Cells of the pooled fragments were dissociated in calcium-free Holtfreter's solution with potassium oxalate and incubated in the presence of different concentrations of phytohemagglutinin and concanavalin A. Epiblast cells overlying the archenteron roof are less agglutinated with both lectins than undetermined cells. On the other hand, when egg fragments were removed from the dorsal and ventral regions of early gastrulae before the archenteron was formed, no significant difference in lectin-mediated agglutinability was observed, even after having been cultured in vitro in absence of inducing tissue. These results suggest that the target of the inducing signal generated in the mesoblast is likely to be located on the surface of epiblast cells. Additional experiments showed that cells pretreated with colchicine, cytochalasin B or colchicine and cytochalasin B simultaneously exhibit no significant variation in agglutinability, suggesting that the cytoskeleton was not be involved in the cell surface alteration here described. Treatment of whole embryos or sandwich explants with concanavalin A or phytohemagglutinin has no effect on neural tube formation, suggesting that the carbohydratecontaining binding sites for these lectins are not involved in primary embryonic induction. Changes in cell agglutinability described in this paper are to be interpreted thus as a secondary expression of structural alterations in the cell surface concomitant with neural determination.

Rapid qualitative changes in mRNA populations in cultured human lymphocytes: comparison of the effects of cycloheximide and concanavalin A

1984 ◽  
Vol 62 (9) ◽  
pp. 859-864 ◽  
Author(s):  
Donald R. Forsdyke
Keyword(s):  
Concanavalin A ◽  
Human Lymphocytes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Lymphocyte Activation ◽  
Relative Mass ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Mrna Species ◽  
Reticulocyte Lysate ◽  
Qualitative Changes

To examine the hypothesis that the stimulation of cultured lymphocytes by lectins involves the inactivation of a protein repressor of putative "activation genes," the effects of a protein synthesis inhibitor (cycloheximide) and a lectin (concanavalin A) were compared. Qualitative changes in mRNA populations were assessed by translating RNA prepared from cycloheximide- or lectin-treated cultures in a rabbit reticulocyte lysate. [35S]Methionine-labelled translation products were analysed by two-dimensional polyacrylamide gel electrophoresis. Cycloheximide increased the radioactive labelling of cultured lymphocytes with the RNA precursor [3H]uridine, as previously reported. This was observed during the first 3 h of culture; thereafter, cycloheximide was inhibitory. The period of increased labelling with [3H]uridine coincided with a period of great increase in mRNA corresponding to an acidic protein of a relative mass of approximately 55 000. This mRNA was not detected in RNA prepared from control cultures, but was one of the most abundant mRNA species detected in RNA prepared from cycloheximide-treated cultures. Increases in certain less abundant mRNA species were also noted. However, the mRNAs were not observed in RNA prepared from lectin-treated cultures. If an increase in these mRNAs is important for lymphocyte activation, then the increase must be to an extent not detected by our current methods.

scholarly journals Cell surface-mediated activation of progelatinase A: demonstration of the involvement of the C-terminal domain of progelatinase A in cell surface binding and activation of progelatinase A by primary fibroblasts

1994 ◽  
Vol 304 (1) ◽  
pp. 263-269 ◽  
Author(s):  
R V Ward ◽  
S J Atkinson ◽  
J J Reynolds ◽  
G Murphy
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Plasma Membranes ◽  
Scatchard Analysis ◽  
Gelatinase A ◽  
Surface Binding ◽  
Binding Studies ◽  
Cell Surface Binding ◽  
Terminal Domain ◽  
Primary Fibroblasts

We report that the isolated C-terminal domain of progelatinase A is inhibitory to the activation of this proenzyme by primary skin fibroblast plasma membranes but is unable to inhibit organomercurial-induced self-cleavage and activation. Ligand binding studies demonstrate that fibroblasts stimulated with concanavalin A to activate progelatinase A have a significantly enhanced level of cell surface-associated progelatinase A. Tissue inhibitor of metalloproteinases-2 (TIMP-2), an effective inhibitor of membrane-mediated progelatinase A activation, is able to abolish the enhanced level of cell surface-associated progelatinase A that occurs following stimulation. TIMP-1, a poor inhibitor of membrane activation, is unable to inhibit the cell surface binding of progelatinase A. The enhancement in the binding of 125I-progelatinase A to fibroblasts following concanavalin A stimulation can be blocked by the inclusion of excess C-terminal gelatinase A but not by a truncated form of gelatinase A lacking the C-terminal domain. Scatchard analysis of the binding of 125I-progelatinase A to concanavalin A-stimulated fibroblasts has identified 950,000 gelatinase binding sites per cell with a Kd of 1.3 x 10(-8) M. Analysis of non-stimulated fibroblasts has identified 500,000 sites per cell with a Kd of 2.6 x 10(-8) M. We propose that membrane-mediated activation of progelatinase A involves binding of the proenzyme through its C-terminal domain to the cell surface and that TIMP-2 can inhibit activation by interaction with progelatinase A through the C-terminal domain, thus preventing binding of the proenzyme.

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