scholarly journals Effects of glutathione-oxidizing agents on microtubule assembly and microtubule-dependent surface properties of human neutrophils.

1976 ◽  
Vol 71 (3) ◽  
pp. 921-932 ◽  
Author(s):  
J M Oliver ◽  
D F Albertini ◽  
R D Berlin
Keyword(s):  
Concanavalin A ◽  
Peripheral Blood ◽  
Polymorphonuclear Leukocytes ◽  
Human Peripheral Blood ◽  
Microtubule Assembly ◽  
Human Neutrophils ◽  
Hexose Monophosphate ◽  
Con A ◽  
Oxidizing Agents ◽  
The Face

In human peripheral blood polymorphonuclear leukocytes and lymphocytes, GSH-oxidizing agents promote the movement of surface-bound concanavalin A (Con A) into caps and inhibit the assembly of microtubules (MT) that is normally induced by Con A binding. Con A capping and inhibition of MT assembly occur when GSH levels in cell suspensions are decreased by 30-70%, and return to GSH to control levels is accompanied by the appearance of cytoplasmic MT and by inhibition of the capping response with Con A. Oxidation of GSH markedly stimulates the hexose monophosphate shunt, and regeneration of GSH occurs rapidly. The data indicate that MT cannot be assembled or maintained in the face of decreased GSH levels. Thus, GSH homeostasis becomes critical during physiological events such as phagocytosis which simultaneously induce the assembly of MT and the production of agents like H2O2 that can oxidize GSH.

scholarly journals Concanavalin A induces microtubule assembly and specific granule discharge in human polymorphonuclear leukocytes.

1976 ◽  
Vol 68 (3) ◽  
pp. 781-787 ◽  
Author(s):  
S Hoffstein ◽  
R Soberman ◽  
I Goldstein ◽  
G Weissmann
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Microtubule Assembly ◽  
Human Neutrophils ◽  
Con A ◽  
Specific Granules ◽  
Specific Granule ◽  
Human Polymorphonuclear Leukocytes

Human neutrophils stimulated by concanavalin A (Con A, 100 microng/ml) contained markedly enhanced numbers of microtubules and discharged peroxidase-negative (specific) but not peroxidase-position (azurophile) granules. Release of lysozyme from specific granules was dose and time dependent, could be inhibitied by alpha-methyl-D-mannoside, and enhanced by cytochalasin B. Many microtubules were associated with internalized plasma membrane bearing Con A binding sites.

scholarly journals RNA and protein synthesis in human peripheral blood polymorphonuclear leukocytes.

1979 ◽  
Vol 149 (1) ◽  
pp. 284-289 ◽  
Author(s):  
A Granelli-Piperno ◽  
J D Vassalli ◽  
E Reich
Keyword(s):  
Protein Synthesis ◽  
Peripheral Blood ◽  
Gel Electrophoresis ◽  
Polymorphonuclear Leukocytes ◽  
Cultured Cells ◽  
Human Peripheral Blood ◽  
Polyacrylamide Gel Electrophoresis ◽  
Con A ◽  
Rna And Protein Synthesis ◽  
Polypeptide Chains

Polymorphonuclear leukocytes purified from human peripheral blood synthesized RNA and proteins when placed in cell culture. Autoradiography of the cultured cells revealed that a majority of mature PMNs were engaged in macromolecule synthesis, and an analysis of newly synthesized proteins by SDS-polyacrylamide gel electrophoresis showed that many different polypeptide chains were synthesized by these cells. The rate of [3H]uridine incorporation and the pattern of newly synthesized proteins were modulated by Con A and glucocorticoids. These results suggest that in spite of their short lifetime and a large performed enzymatic apparatus, mature PMNs retain a substantial capacity for RNA and protein synthesis; and, further, that modulation of macromolecule synthesis forms part of the mechanism by which PMNs respond to inflammatory and anti-flammatory stimuli.

Effect of concanavalin A dose, unbound concanavalin A, temperature, Ca2+ and Mg2+, and vinblastine on capping of concanavalin A receptors of human peripheral blood lymphocytes

1979 ◽  
Vol 36 (1) ◽  
pp. 31-44
Author(s):  
D.K. Bhalla ◽  
C.V. Hunt ◽  
S.P. Kapur ◽  
W.A. Anderson
Keyword(s):  
Horseradish Peroxidase ◽  
Concanavalin A ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Cell Periphery ◽  
Con A ◽  
Morphological Effect ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes

The capping of Concanavalin A (Con A) receptors induced by Con A was studied using human peripheral blood lymphocytes. The effects of Con A dose (5–100 micrograms/ml), pretreatment at 4 degrees C, unbound Con A, extracellular Ca2+ and Mg2+ and vinblastine were evaluated using Con A-horseradish peroxidase and electron microscopy. Lymphocytes incubated with Con A at 4 degrees C and fixed with glutaraldehyde exhibited Con A-horseradish peroxidase around the entire cell periphery. After raising the temperature to 37 degrees C, the Con A-horseradish peroxidase moved to form a cap at one pole of the cell and subsequently underwent endocytosis. Capping of Con A receptors induced by Con A at 37 degrees C was observed only at low Con A concentrations in the presence of unbound Con A and extracellular Ca2+ and Mg2+. Increased capping was found after pretreatment of cells with Con A at 4 degrees C, removing unbound Con A and/or removing extracellular Ca2+ and Mg2+, and by treatment with vinblastine. Following removal of both unbound Con A and extracellular Ca2+ and Mg2+, the percentage of capped cells at 37 degrees C was the same as on pretreatment at 4 degrees C under the same conditions. While pretreatment at 4 degrees C caused the breakdown of microtubules, removal of unbound Con A and/or extracellular Ca2+ and Mg2+ had no morphological effect on microtubules or microfilaments. Following exposure of lymphocytes to vinblastine and removal of unbound Con A, capping of Con A receptors by Con A was observed in over 90% of cells at all Con A dosages. However, when cells were exposed to vinblastine in the presence of unbound Con A the formation of Con A caps was either partially or completely inhibited.

Concanavalin-A displays leishmanicidal activity by inducing ROS production in human peripheral blood mononuclear cells

2018 ◽  
Vol 40 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Ana Paula Fortes dos Santos Thomazelli ◽  
Fernanda Tomiotto-Pellissier ◽  
Milena Menegazzo Miranda-Sapla ◽  
Suelen Santos da Silva ◽  
Daniele Sapede Alvarenga ◽  
...  
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Concanavalin A ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Ros Production ◽  
Peripheral Blood Mononuclear ◽  
Leishmanicidal Activity ◽  
Blood Mononuclear Cells

scholarly journals Human Granulocytic Ehrlichiosis Agent Inhibits Superoxide Anion Generation by Human Neutrophils

2000 ◽  
Vol 68 (12) ◽  
pp. 6697-6703 ◽  
Author(s):  
Jason Mott ◽  
Yasuko Rikihisa
Keyword(s):  
Peripheral Blood ◽  
Superoxide Anion ◽  
Structural Integrity ◽  
Human Peripheral Blood ◽  
Surface Protein ◽  
Host Cells ◽  
Human Neutrophils ◽  
Blood Monocytes ◽  
Granulocytic Ehrlichiosis ◽  
Human Granulocytic Ehrlichiosis

ABSTRACT The human granulocytic ehrlichiosis (HGE) agent, which replicates in neutrophils, was found not to induce superoxide anion (O2 −) generation or extracellular release by human peripheral blood neutrophils, as measured by a luminol-dependent chemiluminescence assay or a cytochrome c reduction assay, respectively. Furthermore, the HGE agent completely prevented O2 − release by neutrophils upon stimulation with phorbol myristate acetate (PMA), formylmethionyl-leucyl-phenylalanine, or Escherichia coli. The inhibition was HGE agent dose dependent, required ehrlichial contact with the host cells, and was reversible upon removal of the extracellular HGE agent bound to the host cells prior to PMA stimulation. Structural integrity of or new protein synthesis by the HGE agent was not required for the inhibition; carbohydrate but not surface protein of the HGE agent was required. The HGE agent did not prevent O2 − generation in human peripheral blood monocytes derived from the same individual. This neutrophil-specific prevention of O2 −generation by the HGE agent would be critical in survival of the HGE agent. This is the first demonstration of the rapid inhibition of preexisting NADPH oxidase in human neutrophils by the HGE agent.

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