Characterization of C3a receptor-proteins on guinea pig platelets and human polymorphonuclear leukocytes

1989 ◽  
Vol 19 (6) ◽  
pp. 1095-1102 ◽  
Author(s):  
Rita Gerardy-Schahn ◽  
Dorothee Ambrosius ◽  
Derek Saunders ◽  
Monica Casaretto ◽  
Christa Mittler ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Polymorphonuclear Leukocytes ◽  
Receptor Proteins ◽  
Human Polymorphonuclear Leukocytes

scholarly journals Release of a Potent Polymorphonuclear Leukocyte Chemoattractant Is Regulated by White-Opaque Switching in Candida albicans

2004 ◽  
Vol 72 (2) ◽  
pp. 667-677 ◽  
Author(s):  
Jeremy Geiger ◽  
Deborah Wessels ◽  
Shawn R. Lockhart ◽  
David R. Soll
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Mating Type ◽  
Related Species ◽  
Polymorphonuclear Leukocytes ◽  
White Phase ◽  
Bona Fide ◽  
Human Polymorphonuclear Leukocytes ◽  
Cell Chemotaxis

ABSTRACT Previous studies employing transmembrane assays suggested that Candida albicans and related species, as well as Saccharomyces cerevisiae, release chemoattractants for human polymorphonuclear leukocytes (PMNs). Because transmembrane assays do not definitively distinguish between chemokinesis and chemotaxis, single-cell chemotaxis assays were used to confirm these findings and test whether mating-type or white-opaque switching affects the release of attractant. Our results demonstrate that C. albicans, C. dubliniensis, C. tropicalis, C. parapsilosis, and C. glabrata release bona fide chemoattractants for PMNs. S. cerevisiae, however, releases a chemokinetic factor but not a chemoattractant. Characterization of the C. albicans chemoattractant revealed that it is a peptide of approximately 1 kDa. Whereas the mating type of C. albicans did not affect the release of chemoattractant, switching did. White-phase cells released chemoattractant, but opaque-phase cells did not. Since the opaque phase of C. albicans represents the mating-competent phenotype, it may be that opaque-phase cells selectively suppress the release of chemoattractant to facilitate mating.

scholarly journals Prevention of degradation of human polymorphonuclear leukocyte proteins by diisopropylfluorophosphate

Blood ◽  
1980 ◽  
Vol 56 (3) ◽  
pp. 442-447 ◽  
Author(s):  
PC Amrein ◽  
TP Stossel
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Actin Binding ◽  
Intact Cells ◽  
Homogenization Treatment ◽  
Human Polymorphonuclear Leukocyte ◽  
Correlating Functions ◽  
Alpha 1 Antitrypsin ◽  
Human Polymorphonuclear Leukocytes ◽  
Neutral Proteases

Abstract Proteases can complicate the characterization of proteins from cells, especially human polymorphonuclear leukocytes (PMN), which contain abundant neutral proteases. We tested the ability of agents to inhibit proteolysis, with special reference to the subunit polypeptides of the contractile proteins actin, myosin, and actin-binding protein (ABP). Phenylmethylsulfonyl fluoride (PMSF), O-phenanthroline, EGTA, EDTA, N- ethylmaleimide, alone or in combinations, failed to prevent extensive proteolysis of the PMN proteins during solubilization of cells with dodecyl sulfate. These inhibitors and also alpha-1-antitrypsin and soybean trypsin inhibitor similarly could not prevent proteolysis during homogenization of cells in cold isosomolar sucrose. Treatment of PMN with greater than or equal to mM diisopropylfluorophosphate (DFP) prior to solubilization or homogenization markedly inhibited proteolysis. PMSF and DFP were equally effective in inhibiting proteolysis in PMN extracts, suggesting that the efficacy of DFP may result from its permeation of intact cells and granules before barriers are disrupted by detergents or homogenization. Treatment of PMN with DFP under conditions inhibiting proteolysis did not affect their rate of phagocytosis. We recommend the use of DFP in future studies correlating functions and protein structure of PMN.

scholarly journals Characterization of an oligopeptide chemoattractant receptor on human blood monocytes using a new radioligand

Blood ◽  
1984 ◽  
Vol 63 (3) ◽  
pp. 588-592 ◽  
Author(s):  
MC Benyunes ◽  
R Snyderman
Keyword(s):  
Human Blood ◽  
Polymorphonuclear Leukocytes ◽  
Specific Radioactivity ◽  
Blood Monocytes ◽  
Chemotactic Peptide ◽  
Peripheral Blood Monocytes ◽  
Peptide Receptor ◽  
Human Polymorphonuclear Leukocytes ◽  
Dissociation Constant Kd

Abstract The study of chemoattractant receptors on human monocytes had been limited by the lack of a radioligand suitable for use with the small numbers of cells routinely available from human donors. A new synthetic oligopeptide radioligand f[35S]met-leu-phe, with a higher specific radioactivity than was available with the tritiated compound, was used to characterize a chemoattractant receptor on freshly isolated human blood monocytes. These cells bind f[35S]met-leu-phe with a dissociation constant (KD) of 30.2 +/- 5.6 nM and contain 84,000 +/- 11,300 receptors per cell. f[35S]met-leu-phe does not bind specifically to blood lymphocytes. The specificity of the oligopeptide receptor on monocytes is indistinguishable from the oligopeptide chemoattractant receptor on human polymorphonuclear leukocytes. Using f[35S]met-leu- phe, it will now be feasible to study the chemotactic peptide receptor on small numbers of partially purified peripheral blood monocytes from patients with defects of immune function.

Characterization of lithium-induced enzyme release from human polymorphonuclear leukocytes

1986 ◽  
Vol 64 (9) ◽  
pp. 880-885 ◽  
Author(s):  
David A. Hart ◽  
Yolanda Groenewoud ◽  
Suzanne Chamberland
Keyword(s):  
Pertussis Toxin ◽  
Polymorphonuclear Leukocytes ◽  
Enzyme Release ◽  
Two Agents ◽  
The Media ◽  
Camp Metabolism ◽  
Human Polymorphonuclear Leukocytes ◽  
Dose Dependent ◽  
Stimulation Of

Lysozyme release from purified human polymorphonuclear leukocytes was found to be uniquely enhanced by 2.5–20 mM LiCl. This effect was dose dependent and was not detected when the media was supplemented with NaCl, KCl, MgCl2, or CaCl2. The purified isotopes of Li+, 6Li, and 7Li were equally effective in enhancing lysozyme release from the cells at 10 and 20 mM, but 6Li was more effective than 7Li at 5 mM. The enhancement of enzyme release in the presence of Li+ was comparable to the enhancement observed in the presence of N-formylmethionylleucylphenylalanine (fMLP). Addition of LiCl plus fMLP did not result in lysozyme release in excess of each stimulant alone, except when the cells were incubated with 20 mM6Li + 10−5 M fMLP. In addition, enzyme release induced by these two agents could be further enhanced to the same degree by addition of cytochasin D to the incubation mixtures. While similarities between enzyme release induced by LiCl and fMLP were detected, optimal stimulation of enzyme release by Li+ was much more sensitive to inhibition by pertussis toxin than was maximal fMLP stimulation. Therefore, the intracellular events altered by Li+ and the peptide may share some metabolic steps, but they differ in their sensitivity to alterations in cAMP metabolism.

scholarly journals The type II "receptor" as a decoy target for interleukin 1 in polymorphonuclear leukocytes: characterization of induction by dexamethasone and ligand binding properties of the released decoy receptor.

1994 ◽  
Vol 179 (2) ◽  
pp. 739-743 ◽  
Author(s):  
F Re ◽  
M Muzio ◽  
M De Rossi ◽  
N Polentarutti ◽  
J G Giri ◽  
...  
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Interleukin 1 ◽  
Soluble Form ◽  
Type I ◽  
Type Ii ◽  
Membrane Expression ◽  
Binding Properties ◽  
Signaling Function ◽  
Human Polymorphonuclear Leukocytes

Whereas the signaling function of the interleukin 1 (IL-1) receptor type I (IL-1R I) has been well documented, the type II "receptor" has been suggested to act as a decoy target for this cytokine. Since IL-1 may represent a key target of the immunomodulatory and antiinflammatory properties of glucocorticoids (GC), the aim of this study was to investigate the effects of dexamethasone (Dex) on IL-1R expression in human polymorphonuclear leukocytes (PMN), which express predominantly the type II molecule (IL-1R II). We found that Dex augments the levels of steady state transcripts encoding the IL-1R I and, most prominently, those of IL-1R II. Dex induced both transcripts via transcription-dependent mechanisms and by prolongation of the mRNAs half-lives. Inhibition of protein synthesis superinduced basal and Dex-augmented IL-1R II mRNA, whereas it completely inhibited the induction by Dex of IL-1R I transcripts. Induction of IL-1R II mRNA by Dex was associated with augmented membrane expression and release of the type II IL-1 binding molecule. This effect was mediated by the GC receptor. Other steroids (17 beta-estradiol, progesterone, and testosterone) were ineffective. The concentrations of IL-1 alpha and IL-1 receptor antagonist required to displace the binding of IL-1 beta to the soluble form of the decoy molecule induced by Dex from PMN were, respectively, 100 and 2 times higher compared with IL-1 beta. The induction by Dex of the type II receptor, a decoy molecule for IL-1, may contribute to the immunosuppressive and antiinflammatory activities of Dex.

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