bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concanavalin A and mistletoe lectin I differentially activate cation entry and exocytosis in human neutrophils: lectins may activate multiple subtypes of cation channels
Authors: Wenzel-Seifert Katharina , Krautwurst Dietmar , Lentzen Hans , Seifert Roland 
Published: January 2018

Abstract
The mannose-specific lectin, concanavalin A (ConA), activates Ca2+ entry in human neutrophils by an as yet poorly defined mechanism. The question of whether the sugar specificity of lectins influences signal transduction is unresolved too. Therefore, we studied the effects of ConA in comparison to those of the β-galactoside-specific lectin, mistletoe lectin I (MLI), on cation entry and exocytosis in human neutrophils. ConA- and MLI-activated influx of Ca2+, Mn2+, Ba2+, Sr2+, and Na+. Lectin-induced cation influxes were inhibited by 1-{β-[3-(4-methoxyphenyl) propoxy]-4-methoxyphenethyl} -1H-imidazole hydrochloride (SK&F 96365) and Gd3+. There were differences in the effectiveness of lectins to activate cation entry and of SK&F 96365, Gd3+, and modulators of protein phosphorylation to block entry. MLI but not ConA inhibited thapsigargin-induced Ca2+ entry. Under whole-cell voltage-clamp conditions, MLI activated an inward current that was substantially reduced by removal of extracellular Na+. ConA and MLI synergistically activated Ca2+ entry and lysozyme release. SK&F 96365 and removal of extracellular Ca2+ and Na+ partially inhibited exocytosis. Our data show the following: (1) ConA and MLI activate monovalent and divalent cation entry in human neutrophils by a SK&F 96365- and Gd3+-sensitive pathway, presumably nonselective cation channels. (2) Ca2+ and Na+ entry are involved in the activation of exocytosis by lectins. (3) The differential and/or synergistic effects of ConA and MLI on cation entry and exocytosis may be attributable to mannose- and β-galactoside-specific activation of signal transduction pathways, i.e., activation of multiple and differentially regulated subtypes of nonselective cation channels.
Fcγ receptor I (CD64)-negative human monocytes are potent accessory cells in viral antigen-induced T cell activation and exhibit high IFN-α-producing capacity
Authors: Grage-Griebenow Evelin , Flad Hans-Dieter , Ernst Martin 
Published: January 2018

Abstract
Blood monocytes represent a heterogeneous cell population with respect to phenotype and function. We have previously described that a minor subset of Fcγ receptor I-negative (CD64−) monocytes, comprising &lt; 10% of all monocytes, exhibits a significantly higher accessory capacity in allogeneic or purified protein derivative (PPD) of tuberculin-induced T cell activation than the majority of CD64-expressing (CD64+) monocytes. CD64− monocytes were also found to represent the major source of Newcastle disease virus (NDV)-induced interferon (IFN)-α within human monocytes. In the present study we demonstrate that CD64− monocytes are also the main producers of IFN-α in response to Herpes simplex virus type 1 (HSV-1) or influenza (type A) antigens. The virus-induced IFN-α release by monocytes, but mainly that by CD64− monocytes, can be further increased by co-culture with autologous T cells, which alone do not produce significant amounts of IFN-α in response to virus. In addition, CD64− and CD64+ monocytes also differ in their accessory capacity in virus-induced T cell responses. CD64− monocytes exposed to influenza antigens induced higher IFN-γ release and proliferation by the responding autologous T cells than virus-exposed CD64+ monocytes. In virus-stimulated monocyte/T cell co-cultures, CD64− monoyctes also induced larger size cell clusters than CD64+ monocytes, indicating direct cell-to-cell interaction with a higher number of T cells, which represent the main component of these clusters.
Osteopontin inhibits nitric oxide production and cytotoxicity by activated RAW264.7 macrophages
Authors: Rollo Ellen E , Laskin Debra L , Denhardt David T 
Published: January 2018

Abstract
Osteopontin (OPN), a secreted acidic phosphoglyeoprotein found in many tissues and body fluids, is produced in increased amounts in response to certain infections and after malignant transformation. In this study we examined the action of OPN on macrophage cytotoxicity and nitric oxide (NO) synthesis. A human OPN cDNA was cloned into the bacteriophage T7-based vector, pET8C, and the encoded protein purified from an induced culture of Escherichia coli carrying the plasmid. Recombinant OPN inhibited NO production by macrophage-like RAW264.7 cells stimulated with lipopolysaccharide plus interferon-γ. OPN also inhibited the cytolytic activity of the activated macrophages toward NO-sensitive P815 mastocytoma cells, an action that was blocked by the NO synthase inhibitor, NG-monomethyl-l-arginine. Inhibition of NO production correlated with an OPN-dependent decrease in the abundance of inducible NO synthase mRNA. The shape of the dose-response curve, with a maximal effect over a narrow range of OPN concentrations, suggested a complex interaction of OPN with cell surface receptors. Our data support the hypothesis that tumor-cell-derived OPN functions to protect the tumor cells from macrophage-mediated destruction.
Prenylation of an interferon-γ-induced GTP-binding protein: the human guanylate binding protein, huGBP1
Authors: Nantais David E , Schwemmle Martin , Stickney John T , Vestal Deborah J , Buss Janice E 
Published: January 2018

Abstract
Interferons (IFN) and lipopolysaccharide (LPS) cause multiple changes in isoprenoid-modified proteins in murine macrophages, the most dramatic being the expression of a prenyl protein of 65 kDa. The guanylate binding proteins (GBPs) are IFN-inducible GTP-binding proteins of ~65 kDa that possess a CaaX motif at their C-terminus, indicating that they might be substrates for prenyltransferases. The human GBP1 protein, when expressed in transfected COS-1 cells, incorporates radioactivity from the isoprenoid precursor [3H]mevalonate. In addition, huGBPs expressed from the endogenous genes in IFN-γ-treated human fibroblasts or monocytic cells were also found to be isoprenoid modified. IFN-γ-induced huGBPs in HL-60 cells were not labeled by the specific C20 isoprenoid, [3H]geranylgeraniol, but did show decreased isoprenoid incorporation in cells treated with the farnesyl transferase inhibitor BZA5B, indicating that huGBPs in HL-60 cells are probably modified by a C15 farnesyl rather than the more common C20lipid. Differentiated HL-60 cells treated with IFN-γ/LPS showed no change in the profile of constitutive isoprenylated proteins and the IFN-γ/LPS-induced huGBPs remained prenylated. Despite being prenylated, huGBP1 in COS cells and endogenous huGBPs in HL-60 cells were primarily (~85%) cytosolic. Human GBPs are thus among the select group of prenyl proteins whose synthesis is tightly regulated by a cytokine. HuGBP1 is an abundant protein whose prenylation may be vulnerable to farnesyl transferase inhibitors that are designed to prevent farnesylation of Ras proteins.
Eosinophil viability during immunoglobulin-induced degranulation
Authors: Weiler Catherine R , Kita Hirohito , Hukee Margaret , Gleich Gerald J 
Published: January 2018

Abstract
Eosinophil adhesion and degranulation appear to be associated with cell death. Eosinophils bound avidly and degranulated with secretory immunoglobulin A (slgA)- and IgG-coupled Sepharose 4B beads but bound poorly and did not degranulate with ovalbumin beads. Through the use of dye staining, we found that about 50% of the bound eosinophils were dead by 4 h, regardless of the protein coating. Colchicine and reduced calcium concentration inhibited binding to beads and eosinophil degranulation in a concentration-dependent manner but did not decrease the percentages of dead bound eosinophils. Electron microscopy showed that eosinophils bound to and spread over bead surfaces. Typical granule exocytosis with release of membrane-free granules occurred in about 20% of bound eosinophils. Eosinophil degeneration and lysis with release of membrane-coated granules occurred in about 50% of bound eosinophils; often only membrane-bound granules were present. Therefore, bound eosinophils degranulate both by classical exocytosis and by release after cytolytic degeneration. By increasing the numbers of bound cells, both IgG and sIgA increase the numbers of dying cells.
Relative role of chloramines, hypochlorous acid, and proteases in the activation of human polymorphonuclear leukocyte collagenase
Authors: Claesson Rolf , Karlsson Magnus , Zhang You Yi , Carlsson Jan 
Published: January 2018

Abstract
The activation of collagenase released by polymorphonuclear leukocytes (PMNs) has been extensively studied in vitro, but the activation of the enzyme in vivo is not fully understood. For further evaluation of the relative role of oxidative and proteolytic mechanisms in the activation of collagenase, PMNs were stimulated by serum-opsonized zymosan under both aerobic and anaerobic conditions. The results showed that similar amounts of collagenase were released by the PMNs under aerobic and anaerobic conditions, but the activity of the released collagenase was twice as high under aerobic conditions as under anaerobic conditions. Under aerobic conditions the enzyme was rapidly activated by hypochlorous acid and chloramines, which are products of the myeloperoxidase-H2O2-chloride system of the PMNs. There was also a slow proteolytic activation of the enzyme, which could be ascribed to cathepsin G and possibly to some other serine proteases of PMNs. When extrapolating these findings to in vivo conditions, it seems probable that the oxidative activation of collagenase will proceed mainly by chloramines, which are more long-lived in the tissue than hypochlorous acid. In poorly oxygenated tissues, collagenase may be mainly activated by proteolytic mechanisms.
Interleukin-4 rapidly down-modulates the macrophage colony-stimulating factor receptor in murine macrophages
Authors: Sbarba Persio Dello , Rovida Elisabetta , Caciagli Barbara , Nencioni Lucia , Labardi Danilo , Paccagnini Alessandro , Savini Luca , Cipolleschi Maria Grazia 
Published: January 2018

Abstract
The activation of macrophages interferes with their response to macrophage colony-stimulating factor (M-CSF), the main growth and differentiation factor for mononuclear phagocytes. We tested the rapid effects of interleukin-4 (IL-4), the alternative macrophage activator produced by Th2 helper lymphocytes, on the receptor for M-CSF (M-CSFR) expressed on the cell surface of murine macrophages. IL-4 rapidly down-modulated M-CSFR in a dose-dependent fashion. This effect was unique to IL-4 among a number of Th2-produced cytokines, none of which, with the exception of IL-4 itself, is able to activate macrophages. The down-modulation of M-CSFR by IL-4 was partially prevented by the inhibition of the activity of phospholipase C or protein kinase C. The data are consistent with the hypothesis that the down-modulation of M-CSFR is a property common to, and exclusive of, macrophage activators, and is driven by different activators via a common mechanism.
Transforming growth factor-β1 stimulates degranulation and oxidant release by adherent human neutrophils
Authors: Balazovich Kenneth J , Fernandez Rosemarie , Hinkovska-Galcheva Vania , Suchard Suzanne J , Boxer Laurence A 
Published: January 2018

Abstract
The signal transduction pathways that are activated by cytokines and growth factors binding to their receptors on human neutrophils (PMN) are poorly understood. When PMN in suspension encounter many of these agonists they are not activated, but rather are primed for subsequent activation. We and others reported that when PMN are plated onto fibrinogen and stimulated with cytokines or with the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) they respond by releasing hydrogen peroxide (H2O2) and the specific granule component lactoferrin. Transforming growth factor-β1 (TGF-β1) is released by many cells including PMN. It has been reported that TGF-β1 stimulates chemotaxis but not exocytosis or superoxide production by cells in suspension. We hypothesized that TGF-β1 would activate PMN to release H2O2 when they were adherent to fibrinogen, a response mediated by β2 integrin receptors. In this study, we determined whether TGF-β1 stimulated H2O2 and lactoferrin release by PMN adherent to fibrinogen. TGF-β1 stimulated H2O2 and lactoferrin release from adherent PMN in a concentration-dependent manner, with effects seen in the range of 0.1 to 100 pg/mL. Both H2O2 and lactoferrin release were detected by 60 min and continued for at least 180 min. Adhesion and spreading of PMN paralleled H2O2 and lactoferrin release. Ethanol (200 mM) blocked both H2O2 and lactoferrin release, suggesting the involvement of the phospholipase D pathway. In PMN labeled with lyso[3H]phoephatidylcholine, we observed that TGF-β1 treatment caused an increase in [3H]phoephatidate. Propranolol (150 μM), an inhibitor of phosphatidate phosphohydrolase, blocked both H2O2 and lactoferrin release, suggesting that the conversion of phosphatidic acid to diradylglycerol is an important step in PMN activation by TGF-β1. Overall, these results are similar to those reported for fMLP activation of adherent PMN and suggest that a common pathway is involved in both chemoattractant and cytokine activation.
Monocyte chemoattractant protein-1: receptor interactions and calcium signaling mechanisms
Authors: Needham M , Sturgess N , Cerillo G , Green I , Warburton H , Wilson R , Martin L , Barratt D , Anderson M , Reilly C , Hollis M 
Published: January 2018

Abstract
Monocyte chemoattractant protein-1 (MCP-1) is a member of the Cys-Cys chemokine family. Two related MCP-1 receptors have been identified (CC-CKR2A and CC-CKR2B), although the precise kinetics of ligand binding and calcium signaling of these receptors has yet to be investigated, To examine this more closely, the human MCP-1 receptors were cloned and expressed in Chinese hamster ovary (CHO) cells. Membranes prepared from cells expressing CC-CKR2B bind MCP-1 selectively and with high affinity (Kd = 120 pM). MCP-1 stimulation of recombinant CHO cells expressing CC-CKR2B induces a rapid increase in intracellular Ca2+ through both receptor-operated Ca2+ channels and mobilization of Ca2+ from intracellular stores, and leads to a rapid temperature-dependent internalization of the ligand/receptor complexes. In contrast, recombinant CHO cells expressing CC-CKR2A, and membranes prepared from these cells, fail to bind detectable levels of MCP-1. However, MCP-1 stimulation of cells expressing CC-CKR2A induces a small but significant increase in intracellular Ca2+. Repeated stimulation of these cells with MCP-1 leads to a potentiation of the response to a level comparable to that seen in cells expressing CC-CKR2B. These observations suggest that the levels of cell surface CC-CKR2A are controlled by novel mechanisms.
Characterization of the processing and granular targeting of human proteinase 3 after transfection to the rat RBL or the murine 32D leukemic cell lines
Authors: Garwicz Daniel , Lindmark Anders , Hellmark Thomas , Gladh Mathias , Jögi Jonas , Gullberg Urban 
Published: January 2018

Abstract
Proteinase 3 (PR3) is a neutrophil serine protease stored in the azurophil granules of the promyelocyte and its successors. The protease has been identified as an autoantigen for anti-neutrophil cytoplasmic autoantibodies (ANCA) occurring in patients with Wegener's granulomatosis. To characterize the biosynthesis and processing of human PR3 in a transgenic cellular model, cDNA encoding human pre-proproteinase 3 cloned from U-937 cells was transfected to the rat basophilic/mast cell line RBL-1 and the murine myeloblast-like cell line 32D cl3. The stable expression of transgenic proteinase 3 was characterized by biosynthetic labeling, followed by immunoprecipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography. After pulse labeling for 30 min two proforms of PR3 (32 and 35 kDa), differing in carbohydrate content but with protein cores of identical size, were demonstrated. Chase of the label resulted in a processed 32-kDa form clearly visible in RBL, but only faintly in 32D cells, probably indicating delayed intracellular transfer in the latter cell line. Partial digestion with N-glycosidase F showed that both potential N-glycosylation sites on PR3 were occupied and conversion of the oligosaccharide side chains into complex forms was demonstrated by acquisition of resistance to endoglycosidase H. Translocation of PR3 to granules was shown by subcellular fractionation and immunocytochemistry. Enzymatic activation of PR3 was suggested by affinity to diisopropylfluorophosphate and removal of an amino-terminal propeptide. Cells transfected with PR3 showed positive immunofluorescence for ANCA-containing sera from patients with Wegener's granulomatosis. Our results show that human PR3 transfected to RBL or 32D cells is synthesized as a 29-kDa protein core glycosylated on two distinct sites. Oligosaccharide trimming and proteolytic processing occur and the protein is targeted for granular storage in a form antigenic for ANCA.
Alteration of deacylated lipopolysaccharide antagonistic properties by interaction with plasma factors
Authors: Mey Anne , Hmama Zakaria , Normier Gérard , Revillard Jean-Pierre 
Published: January 2018

Abstract
The acyl poly(l,3)galactoside (APG) from Klebsiella pneumoniae is a bis-acylated lipopolysaccharide (LPS) devoid of ester-linked fatty acids. APG interacts with CD14 and CD11b/CD18 on monocytes. This study addressed the role of serum proteins in the binding and functional properties of APG as a candidate LPS antagonist. In the absence of serum, APG did not induce tumor necrosis factor α (TNF-α) synthesis by human mononuclear cells and dose-dependently inhibited their activation induced by different LPS. Conversely, in the presence of 5% autologous plasma, APG activated cells and did not antagonize LPS. Serum decreased APG but not LPS binding to monocytes. Binding competition experiments indicated that APG and LPS competed for the same receptors in serum-free conditions but bound to different receptors in the presence of plasma. The data indicate that serum-dependent LPS receptors do contribute to LPS activation of monocytes but do not recognize deacylated LPS analogues.
Elevated levels of NO in both unchallenged and LPS-challenged C. parvum-primed mice are attributable to the activity of a cytokine-inducible isoform of iNOS
Authors: Smith Sidney R , Manfra Denise , Davies Liza , Terminelli Carol , Denhardt Georgette , Donkin Jennifer 
Published: January 2018

Abstract
Elevated levels of nitric oxide (NO2-/NO3-) were detected in the serum of mice 3–7 days after priming with Corynebacterium parvum (Propiombacterium acnes). The serum NO2-/NO3- response was completely inhibited when C. parvum-primed (C. parvum) mice were treated with NG-monomethyl-l-arginine (l-NMMA) or aminoguanidine (AG) on days 6 and 7 post priming. The response was also inhibited when the mice were treated with interleukin-10 (IL-10) and the cytokine was most effective when given in multiple doses beginning on the day of priming. In contrast to l-NMMA and AG, IL-10 had no effect on the serum NO2-/NO3- response when administered to the mice on days 6 and 7 post priming. The inducible isoform of NOS (iNOS) appeared to be responsible for the elevated NO2-/NO3- response in C. parvum mice because iNOS transcripts were readily detected in their livers. Moreover, these transcripts as well as the circulating levels of NO2-/NO3- were dramatically reduced when the mice were treated with anti-tumor necrosis factor α (anti-TNF-α) or antiinterferon-γ (anti-IFN-γ) monoclonal antibodies (mAbs) during the priming interval. There was a modest increase (less than twofold) in the serum NO2-/NO3-response following a lipopolysaccharide (LPS) challenge to C. parvum mice (C. parvum/LPS mice). LPS had a more dramatic stimulatory effect if the levels of NO2-/NO3- preexisting in C. parvum/LPS mice were reduced by treatment with l-NMMA, AG, or IL-10 before the challenge. Thus the levels of NO2-/NO3-that preexisted in C. parvum/LPS mice appeared to influence their ability to mount a NO2-/NO3- response subsequent to the LPS challenge. The NO2-/ NO3- response did not contribute to lethality in C. parvum/LPS mice because anti-TNF-α and anti-IFN-γ mAbs were protective but had no effect on serum NO2-/NO3- levels when administered to mice 24 h before the LPS challenge.
Growth-inhibitory and apoptosis-inducing activities of calprotectin derived from inflammatory exudate cells on normal fibroblasts: regulation by metal ions
Authors: Yui Satoru , Mikami Masaaki , Tsurumaki Kazusa , Yamazaki Masatoshi 
Published: January 2018

Abstract
We have shown previously that a calcium-binding protein complex, calprotectin, derived from polymorphonuclear leukocytes exerts a cytostatic and cytolytic effect against a very broad range of tumor cell lines. We also described that calprotectin is an apoptosis-inducing factor for certain tumor cells and that zinc ion attenuates the calprotectin activities. The titers of the factor in body fluids are known to increase greatly in various types of inflammation. In this study, to learn the role of calprotectin in inflammation, the growth-inhibitory and the apoptosis-inducing activities of the factor against normal fibroblasts were examined because fibroblasts are a cell type constituting a local inflammatory site. Bat calprotectin inhibited the growth of murine embryonic as well as human dermal fibroblasts. Although calprotectin induced apoptotic morphology in both fibroblasts, the reaction was slower and less efficient than cases using tumor cells as targets. The activities were significantly abrogated by 10–50 μM Zn2+, Cu2+, Mn2+, or Fe2+, respectively, whereas the trivalent cations Al3+ and Fe3+ had no effect. The dose-response curves of the calprotectin effects were shifted to about 10-fold lower concentration ranges in the divalent metal ion-depleted medium. These results suggest that calprotectin extracellularly affects the inflammatory processes by modulating the growth and survival states of normal fibroblasts, and that the effects are physiologically controlled by several metal ions.