scholarly journals Selective release of lysosomal hydrolases from phagocytic cells by cytochalasin B

1973 ◽  
Vol 134 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Philip Davies ◽  
Anthony C. Allison ◽  
A. David Haswell
Keyword(s):  
Lactate Dehydrogenase ◽  
Cytochalasin B ◽  
Polymorphonuclear Leucocyte ◽  
Polymorphonuclear Leucocytes ◽  
Enzyme Release ◽  
Acid Hydrolases ◽  
Phagocytic Cells ◽  
Lysosomal Hydrolases ◽  
Secondary Lysosomes ◽  
Dose Dependent

1. Cytochalasin B (10μg/ml) enhances the release of rabbit polymorphonuclear leucocyte lysosomal acid hydrolases induced by retinol (vitamin A alcohol). 2. This effect is seen at doses of the vitamin that cause selective release of acid hydrolases and those causing more general enzyme release indicated by the loss of lactate dehydrogenase. 3. Cytochalasin B (2–50μg/ml) has no effect on the release of sedimentable acid hydrolases of intact granules obtained from disrupted polymorphonuclear leucocytes. 4. Cytochalasin B (2–10μg/ml) causes a time- and dose-dependent release of mouse peritoneal macrophage acid hydrolases. 5. This effect is selective at all doses of cytochalasin B used, since no release of lactate dehydrogenase, malate dehydrogenase and leucine 2-naphthylamidase was detected. 6. Treatment with cytochalasin B at doses of up to 10μg/ml for as long as 72h did not significantly change the total activities of any of the enzymes measured. 7. The lack of toxicity of cytochalasin B was shown by dye-exclusion tests and its failure to release radioactive colloidal gold stored in secondary lysosomes.

FMLP-induced enzyme release from neutrophils: a role for intracellular calcium

1983 ◽  
Vol 245 (3) ◽  
pp. C196-C202 ◽  
Author(s):  
D. Chandler ◽  
G. Meusel ◽  
E. Schumaker ◽  
C. Stapleton
Keyword(s):  
Intracellular Calcium ◽  
Cytochalasin B ◽  
Calcium Ionophore ◽  
Cell Ultrastructure ◽  
Calcium Ionophore A23187 ◽  
Extracellular Calcium ◽  
Ionophore A23187 ◽  
Enzyme Release ◽  
Calcium Depletion ◽  
Dose Dependent

The ability of the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (FMLP) to stimulate beta-glucuronidase release and 45Ca2+ release from rabbit neutrophils was studied. FMLP stimulated enzyme release from cytochalasin B-treated cells either in the presence or the absence of extracellular calcium. Depletion of cell calcium, by exposure to either ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid or the calcium ionophore A23187, blocked the ability of FMLP to stimulate enzyme release and 45Ca2+ release in the absence of extracellular calcium. The ability of A23187 to lower the 45Ca2+ content of neutrophils, to block FMLP-stimulated 45Ca2+ release, and to inhibit FMLP-stimulated enzyme release in the absence of calcium was dose dependent over the same concentration range (10(-8) to 10(-6) M A23187) for all three actions. In contrast, FMLP stimulated enzyme release from A23187-treated cells, provided that extracellular calcium was present. This secretory response was normal as judged by cell ultrastructure and FMLP dose-response relationships. It is concluded that A23187 depletes a pool of intracellular calcium usually released by FMLP and that release of calcium from this pool is necessary for initiation of enzyme secretion in the absence of extracellular calcium.

MECHANISMS OF LYSOSOMAL ENZYME RELEASE FROM LEUKOCYTES EXPOSED TO IMMUNE COMPLEXES AND OTHER PARTICLES

1971 ◽  
Vol 134 (3) ◽  
pp. 149-165 ◽  
Author(s):  
Gerald Weissmann ◽  
Robert B. Zurier ◽  
Paul J. Spieler ◽  
Ira M. Goldstein
Keyword(s):  
Immune Complexes ◽  
Lysosomal Enzymes ◽  
Tris Buffer ◽  
Selective Absorption ◽  
Enzyme Release ◽  
Acid Hydrolases ◽  
Lysosomal Hydrolases ◽  
Fresh Serum ◽  
Inert Particles ◽  
Oxidation Of Glucose

Human PMN release lysosomal enzymes (ß-glucuronidase, acid phosphatase) when exposed to immune complexes, but do not release cytoplasmic LDH. The cells remain viable, and failure of LDH to appear in supernatants is not due to selective absorption or inactivation. Release of enzymes is not due to platelet contamination and is only partially enhanced by fresh serum. The selective release of lysosomal enzymes after uptake of complexes resembles that induced by inert particles of zymosan, and can be distinguished from the concurrent release of all enzymes after cell death induced by membrane-lytic crystals of MSU. Uptake of complexes, zymosan, or MSU particles is accompanied by concomitant increases in C-1 oxidation of glucose. Although MSU-induced damage can be retarded by the presence of Tris buffer, immune complexes and zymosan selectively release lysosomal hydrolases in the presence or absence of Tris buffer. Agents which elevate the level, within cells, of cAMP (PGE1, theophylline, 2-CA) and cAMP itself inhibit the selective extrusion of acid hydrolases from leukocytes without affecting the viability of cells. Leukocytes may respond to immune particles by regurgitating a portion of their lysosomal hydrolases during phagocytosis.

scholarly journals The role of polyphosphoinositides and their breakdown products in A23187-induced release of arachidonic acid from rabbit polymorphonuclear leucocytes

1986 ◽  
Vol 238 (2) ◽  
pp. 425-436 ◽  
Author(s):  
C J Meade ◽  
G A Turner ◽  
P E Bateman
Keyword(s):  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Phospholipase A2 ◽  
Phospholipase C ◽  
Cytochalasin B ◽  
Polymorphonuclear Leucocyte ◽  
Limiting Factor ◽  
Polymorphonuclear Leucocytes ◽  
Hydrolysis Of

Stimulation of rabbit polymorphonuclear leucocytes with A23187 causes phospholipase C mediated breakdown of polyphosphoinositides, as evidenced by accumulation of [3H]inositol-labelled inositol bisphosphate and inositol trisphosphate. At the same time the polyphosphoinositides and the products of their breakdown, diacylglycerol and phosphatidic acid, label rapidly with radioactive arachidonic acid. Enhancement of polyphosphoinositide labelling is not as great as enhancement of diacylglycerol or phosphatidic acid labelling, suggesting additional early activation of a second independent synthetic pathway to the last named lipids. Experiments using double (3H/14C) labelling, to distinguish pools with different rates of turnover, suggest the major pool of arachidonic acid used for synthesis of lipoxygenase metabolites turns over more slowly than arachidonic acid in diacylglycerol, but at about the same rate as arachidonic acid esterified in phosphatidylcholine or phosphatidylinositol. Further, when cells are prelabelled with [14C]arachidonic acid, then stimulated for 5 min, it is only from phosphatidylcholine, and to a lesser extent phosphatidylinositol, that radiolabel is lost. Release of arachidonic acid is probably via phospholipase A2, since it is blocked by the phospholipase A2 inhibitor manoalide. The absence of accumulated lysophosphatides can be explained by reacylation and, in the case of lysophosphatidylinositol, deacylation. The importance of phospholipase A2 in phosphatidylinositol breakdown contrasts with the major role of phospholipase C in polyphosphoinositide hydrolysis. Measurements of absolute free fatty acid levels, as well as studies showing a correlation between production of radiolabelled hydroxyeicosatetraenoic acids and release of radiolabel from the phospholipid pool, both suggest that hydrolysis of arachidonic acid esterified into phospholipids is the limiting factor regulating formation of lipoxygenase metabolites. By contrast with A23187, fMet-Leu-Phe (a widely used polymorphonuclear leucocyte activator) is a poor stimulant for arachidonic acid release unless a ‘second signal’ (e.g. cytochalasin B, or a product of A23187-stimulated cells) is also present. In the presence of cytochalasin B, fMet-Leu-Phe, like A23187, stimulates release of radiolabelled arachidonic acid principally from phosphatidylcholine.

scholarly journals THE FATE OF BACTERIA WITHIN PHAGOCYTIC CELLS

1963 ◽  
Vol 117 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Zanvil A. Cohn
Keyword(s):  
Inorganic Phosphate ◽  
Degradation Products ◽  
Cell Types ◽  
Polymorphonuclear Leucocyte ◽  
Polymorphonuclear Leucocytes ◽  
Phagocytic Cells ◽  
Small Molecular Weight ◽  
Bacterial Rna ◽  
Extensive Degradation ◽  
Bacterial Constituents

The intraleucocytic fate of a variety of P32- and C14-labeled bacteria has been studied in both polymorphonuclear leucocytes and macrophages. Both cell types brought about extensive degradation of bacterial lipids, nucleic acids, and proteins. Intracellular breakdown was primarily dependant upon the composition of the ingested particle rather than on the type or source of the phagocyte. Evidence is presented for the reincorporation of bacterial constituents into leucocyte lipid. More than 50 per cent of the acid-soluble degradation products of P32-labeled bacteria appear as inorganic phosphate. Bacterial RNA is degraded more readily than DNA. Following phagocytosis, labeled bacteria lose their pool of small molecular weight intermediates. This is followed by the degradation of acid-insoluble constituents. The majority of bacterial breakdown products are then excreted by the leucocyte and appear in the medium. Heat-killed bacteria were more readily broken down than viable organisms. Only small amounts of C14-labeled bacteria were completely oxidized by leucocytic enzymes to C14O2. Acid extracts of polymorphonuclear leucocyte granules, which were highly bactericidal, liberated the acid-soluble constituents of labeled bacteria but did not significantly degrade bacterial macromolecules.

scholarly journals The effect of feeding structured triacylglycerols enriched in eicosapentaenoic or docosahexaenoic acids on murine splenocyte fatty acid composition and leucocyte phagocytosis

2003 ◽  
Vol 90 (6) ◽  
pp. 1071-1080 ◽  
Author(s):  
Samantha Kew ◽  
Edward S. Gibbons ◽  
Frank Thies ◽  
Gerald P. McNeill ◽  
Paul T. Quinlan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Linolenic Acid ◽  
Control Diet ◽  
Phagocytic Cells ◽  
Dose Dependent Fashion ◽  
Total Fatty Acids ◽  
Structured Triacylglycerols ◽  
Dose Dependent ◽  
Effect Of Feeding ◽  
Docosahexaenoic Acids

The effects of altering the type of n-3 polyunsaturated fatty acid (PUFA) in the mouse diet on the ability of monocytes and neutrophils to perform phagocytosis were investigated. Male weanling mice were fed for 7 d on one of nine diets which contained 178 g lipid/kg and which differed in the type of n-3 PUFA and in the position of these in dietary triacylglycerol (TAG). The control diet contained 4·4 g α-linolenic acid/100 g total fatty acids. In the other diets, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) replaced a proportion (50 or 100 %) of the α-linolenic acid, and were in the sn-2 or the sn-1(3) position of dietary TAG. There were significant increases in the content of n-3 PUFA in spleen-cell phospholipids when EPA or DHA was fed. These increases were largely independent of the position of EPA or DHA in dietary TAG except when EPA was fed at the highest level, when the incorporation was greater when it was fed in the sn-2 than in the sn-1(3) position. There was no significant effect of dietary DHA on monocyte or neutrophil phagocytic activity. Dietary EPA dose-dependently decreased the number of monocytes and neutrophils performing phagocytosis. However, when EPA was fed in the sn-2 position, the ability of active monocytes or neutrophils to engulf bacteria was increased in a dose-dependent fashion. This did not occur when EPA was fed in the sn-1(3) position. Thus, there appears to be an influence of the position of EPA, but not of DHA, in dietary TAG on its incorporation into cell phospholipids and on the activity of phagocytic cells.

scholarly journals Thrombospondin receptor expression in human neutrophils coincides with the release of a subpopulation of specific granules

1992 ◽  
Vol 284 (2) ◽  
pp. 513-520 ◽  
Author(s):  
S J Suchard ◽  
M J Burton ◽  
S J Stoehr
Keyword(s):  
Cytochalasin B ◽  
Anion Channel ◽  
Polymorphonuclear Leucocyte ◽  
Receptor Expression ◽  
Human Neutrophils ◽  
Ionophore A23187 ◽  
Surface Receptors ◽  
Specific Granules ◽  
Azurophil Granule ◽  
Disulphonic Acid

The extracellular matrix (ECM) protein thrombospondin (TSP) binds specifically to polymorphonuclear leucocyte (PMN) surface receptors and promotes cell adhesion and motility. TSP receptor expression increases 30-fold after activation with the synthetic chemotactic peptide, N-formylmethionyl-leucylphenylalanine (FMLP) or the Ca2+ ionophore A23187, in combination with cytochalasin B. The expression of TSP receptors was correlated with the exocytosis of both specific and azurophil granules. Newly expressed TSP receptors are not derived from easily mobilized specific granules since agents that trigger some specific granule release [phorbol myristate acetate (PMA), FMLP or ionophore A23187 alone] do not increase TSP receptor expression. In this study we used the anion-channel blocker, 4,4′-di-isothiocyanatostilbene-2,2′-disulphonic acid (DIDS) to investigate the source of these newly expressed receptors. When PMNs were exposed to cytochalasin B and FMLP or to cytochalasin B and ionophore A23187 in the presence of 30-100 microM-DIDS, TSP receptor expression increased coincidently with vitamin B12-binding protein release from specific granules. Under these same conditions, the release of the azurophil granule component, myeloperoxidase, was significantly inhibited. Using agonists that cause release of specific granules, or both specific granules and azurophil granules, we determined that DIDS blocked the release of PMA-mobilized specific granules and cytochalasin B plus FMLP- or cytochalasin B plus ionophore A23187-mobilized myeloperoxidase-containing azurophil granules but not specific granules mobilized by cytochalasin B plus FMLP or cytochalasin B plus ionophore A23187. These results suggested that PMNs contain at least two subpopulations of specific granules: one that is easily mobilized, lacks TSP receptors and is inhibitable by DIDS, and one that is difficult to mobilize, contains a large pool of TSP receptors and the release of which is enhanced in the presence of DIDS.

Release of intestinal diamine oxidase by histamine in rats

1983 ◽  
Vol 61 (4) ◽  
pp. 349-355 ◽  
Author(s):  
Armin Wollin ◽  
Henri Navert
Keyword(s):  
Intestinal Mucosa ◽  
Oxidase Activity ◽  
Diamine Oxidase ◽  
Fold Increase ◽  
Lymph Flow ◽  
Intestinal Lumen ◽  
Enzyme Release ◽  
Storage Site ◽  
Diamine Oxidase Activity ◽  
Dose Dependent

Diamine oxidase activity was measured in the intestinal mucosa, lymph, and in the serum of rats, to determine whether histamine, a substrate of diamine oxidase, liberates this enzyme from its mucosal storage site(s). Histamine induced a sharp rise in intestinal lymph flow, lymph protein, and lymph diamine oxidase, lasting less than 1 h after the histamine injection. The rise in lymph diamine oxidase activity was dose dependent over a narrow concentration range (0.05–0.2 mmol/kg, i.v. and 0.15–0.6 mmol/kg i.d.). It did not correlate with the dose dependent increase in lymph flow or lymph protein. A single maximal intraduodenal dose of histamine caused a 41.6-fold increase in the lymph diamine oxidase activity and a 2.4-fold increase in the serum enzyme level temporarily. A second injection of histamine, 2 h after the first, resulted in a comparatively smaller increase in the lymph enzyme. The extent of the reduction was dependent on the magnitude of the first injection. The results suggest that histamine causes a limited liberation of diamine oxidase from the intestinal mucosa. The function of this enzyme release may be a protective response by the mucosa to reduce toxic levels of free histamine, either liberated by the mucosal tissue or absorbed from the intestinal lumen.

scholarly journals Enhanced Killing of Candida krusei by Polymorphonuclear Leucocytes in the Presence of Subinhibitory Concentrations of Melaleuca alternifolia and “Mentha of Pancalieri” Essential Oils

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3824
Author(s):  
Vivian Tullio ◽  
Janira Roana ◽  
Daniela Scalas ◽  
Narcisa Mandras
Keyword(s):  
Essential Oils ◽  
Direct Action ◽  
Candida Krusei ◽  
Polymorphonuclear Leucocytes ◽  
Intracellular Killing ◽  
Phagocytic Cells ◽  
Positive Interaction ◽  
Reference Drug ◽  
Tea Tree ◽  
Diphenyltetrazolium Bromide

The aim of this study was to evaluate the influence of tea tree oil (TTO) and “Mentha of Pancalieri” essential oil (MPP) on intracellular killing of Candida krusei, often resistant to conventional drugs, by polymorphonuclear leucocytes (PMNs). Intracellular killing was investigated by incubating yeasts and PMNs with essential oils (EOs) at 1/4 and 1/8 × MIC (Minimal Inhibitory Concentration), in comparison with anidulafungin, used as a reference drug. Killing values were expressed as Survival Index (SI) values. The cytotoxicity of EOs was evaluated by 3-[4,-5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Both EOs were more efficaceous at 1/8 × MIC than 1/4 × MIC, with killing values higher than observed in EO-free systems and in presence of anidulafungin, indicating that the decreasing concentrations did not cause lower candidacidal activity. This better activity at 1/8 × MIC is probably due to the EOs’ toxicity at 1/4 × MIC, suggesting that at higher concentrations EOs might interfere with PMNs functionality. TTO and MPP at 1/8 × MIC significantly increased intracellular killing by PMNs through their direct action on the yeasts (both EOs) or on phagocytic cells (MPP), suggesting a positive interaction between EOs and PMNs to eradicate intracellular C. krusei. These data showed a promising potential application of TTO and “Mentha of Pancalieri” EO as natural adjuvants in C. krusei infection management.

scholarly journals THE EFFECT OF POLY-L-LYSINE ON THE UPTAKE OF REOVIRUS DOUBLE-STRANDED RNA IN MACROPHAGES IN VITRO

1973 ◽  
Vol 57 (2) ◽  
pp. 484-498 ◽  
Author(s):  
Rolf Seljelid ◽  
Samuel C. Silverstein ◽  
Zanvil A. Cohn
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Nucleic Acids ◽  
Acid Hydrolases ◽  
Cell Compartment ◽  
Double Stranded Rna ◽  
Secondary Lysosomes ◽  
Toxic Concentrations ◽  
Vacuolar System

The effect of polycations on cultured mouse peitoneal macrophages has been examined. Polycations, at concentrations greater than 5 µg/ml, are toxic for macrophages) as measured by failure of the cells to exclude vital dyes. At toxic concentrations polycations bind in large amounts to nuclei and endoplasmic reticulum, while at nontoxic levels polycations bind selectively to the cell surface. Nontoxic concentrations of polycations stimulate binding of reovirus double-stranded (ds) RNA to the macrophages by forming polycation-dsRNA complexes either in the medium or at the cell surface. These complexes enter the cell in endocytic vacuoles and are concentrated in secondary lysosomes. Despite exposure to the acid hydrolases within this cell compartment, the dsRNA and the polycation (poly-L-lysine) are conserved in a macromolecular form within the vacuolar system. The mechanism(s) by which the uptake of infectious nucleic acids and the induction of interferon by dsRNA are stimulated by polycations are discussed.

scholarly journals Antioxidants the Powerful New Weapons in the Fight Against Periodontal Diseases

2013 ◽  
Vol 01 (02) ◽  
pp. 085-090 ◽  
Author(s):  
Baljeet Singh ◽  
Shivani Bhickta ◽  
Rajesh Gupta ◽  
Sachin Goyal ◽  
Ram Gupta
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Connective Tissue ◽  
Chronic Inflammation ◽  
Inflammatory Cell ◽  
Periodontal Diseases ◽  
Polymorphonuclear Leucocyte ◽  
Oxygen Species ◽  
Phagocytic Cells ◽  
Extracellular Release

AbstractThe human inflammatory periodontal diseases are amongst the most common of chronic diseases. The predominant inflammatory cell (96%) within the healthy connective tissue and epithelium of the gingiva is polymorphonuclear leucocyte (PMNL). Periodontopathic bacteria in the gingivomucosal tissue may functionally activate PMNLs leading to an increased production of reactive oxygen species (ROS). Chronic inflammation subjects the nearby cells to elevated levels of free radicals (ROS) due to extracellular release from phagocytic cells. Antioxidants block the process of oxidation by neutralizing free radicals. In doing so, the antioxidant themselves become oxidized. Because of this, there is a constant need to replenish our antioxidant resources.

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