bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exposure of cultured murine peritoneal macrophages to low concentrations of beryllium induces increases in intracellular calcium concentrations and stimulates DNA synthesis
Authors: Misra Uma K , Gawdi G , Pizzo Salvatore V , Lewis James G 
Published: January 2018

Abstract
Exposure of humans to beryllium dusts can induce a specific form of chronic pneumonitis that consists mainly of noncaseating granulomas in the lungs. Multiple studies have documented both genetic and immune components of chronic berylliosis. Much work has focused on T cells and their reactivity in berylliosis, but less work has focused on the end effector cells in granulomatous inflammation, macrophages. Because macrophages must become activated to form granulomas, and they become activated by responding to numerous immunomodulatory signals, we investigated the effects of beryllium (BeCl2) on a central signal transduction pathway in macrophages, increases in intracellular calcium ([Ca2+]i). Exposure of cultured murine peritoneal macrophages to low, non-toxic concentrations induced successive spikes or oscillations in [Ca2+]i. Concentrations as low as 5 nM induced significant increases in [Ca2+]i. The source of the increased [Ca2+]i was exclusively extracellular in that increases in [Ca2+]i could be completely blocked by chelating extracellular Ca2+, were inhibited by the Ca2+ channel blocker verapamil, and exposure of macrophages to BeCl2 had no effect on IP3 concentrations. DNA synthesis, a Ca2+-sensitive function, was enhanced in dividing 1LN cells and induced de novo in quiescent macrophages. Furthermore, BeCl2 enhanced DNA synthesis in the absence of coexposure to the protein kinase C activator phorbol myristate acetate. These data support the hypothesis that beryllium toxicity is in part the result of altered Ca2+ metabolism in mononuclear phagocytes consequent to reversible opening of plasma membrane channels. J. Leukoc. Biol. 65: 786–791; 1999.
Aspirin-induced increases in soluble IL-1 receptor type II concentrations in vitro and in vivo
Authors: Daun Jane M , Ball Richard W , Burger Heather R , Cannon Joseph G 
Published: January 2018

Abstract
This study examined the influence of low-dose aspirin on interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), and soluble receptor type II (sIL-1RII) secretion in vivo and in vitro. Blood mononuclear cells were isolated from healthy young men who ingested 81 mg of aspirin on alternate days for 2 weeks and from unmedicated controls. Aspirin had minor effects on ex vivo secretion of IL-1β and no influence on IL-1ra. In contrast, unstimulated ex vivo secretion of sIL-1RII was over twice as high by cells from aspirin-treated subjects (1115 ± 123 vs. 460 ± 77 pg/mL, P = 0.02). Lipopolysaccharide-stimulated sIL-1RII secretion was influenced similarly. Plasma sIL-1RII concentrations were 23% higher in aspirin-treated subjects (10.2 ± 0.6 vs. 8.4 ± 0.3 ng/mL, P = 0.03). In addition, cells from unmedicated subjects cultured in vitro with aspirin (10 μg/mL) secreted significantly greater amounts of sIL-1RII. Thus, low-dose aspirin therapy may prevent inflammation by increasing soluble receptor secretion, thereby preventing IL-1 from binding target cells. J. Leukoc. Biol. 65: 863–866; 1999.
Inhibitors of PI 3-kinase and MEK kinase differentially affect mediator secretion from immunologically activated human basophils
Authors: Gibbs Bernhard F , Grabbe Jurgen 
Published: January 2018

Abstract
Effects of inhibitors of PI 3-kinase and MEK kinases were investigated on histamine, leukotriene C4 (LTC4), and cytokine release from human basophils stimulated with anti-IgE. The PI 3-kinase antagonists wortmannin (&gt; 10 nM) and LY 294002 (&gt; 1 μM) strongly inhibited anti-IgE-induced release of all mediators by 40–100%. This was contrasted by the effects of the MEK kinase inhibitor PD 098059, which weakly inhibited histamine, interleukin (IL)-4, and IL-13 release but was substantially more efficacious at blocking LTC4 production (&gt; 70% at 10 μM). Previous studies have shown that arachidonic acid synthesis is controlled by MEK kinases. We observed that wortmannin, LY 294002, and PD 098059 reduce basophil ERK-1,2 activation, thus implying that, with regard to arachidonic acid metabolism, MEK kinases are a downstream target for PI-3-kinase. Our results demonstrate a universal regulatory role played by PI 3-kinases in basophil mediator production and release, whereas MEK kinase signaling is largely limited to controlling arachidonic acid metabolism. J. Leukoc. Biol. 65: 883–890; 1999.
Neutrophil migration during endotoxemia
Authors: Wagner James G , Roth Robert A 
Published: January 2018

Abstract
Endotoxemia is marked by a global activation of inflammatory responses, which can lead to shock, multiple organ failure, and the suppression of immune and wound healing processes. Neutrophils (PMNs) play a central role in some of these responses by accumulating in tissues and releasing reactive oxygen species and proteases that injure host structures. This review focuses on altered PMN migratory responses that occur during endotoxemia and their consequences in the development of pulmonary infection. The inflammatory mediators that might be responsible for these altered responses are discussed. The oxidant potential of PMNs is increased after exposure to endotoxin both in vitro and during clinical and experimental endotoxemia. However, other functions such as chemotaxis and phagocytosis are often depressed in these same cells. Endotoxin exposure renders PMNs hyperadhesive to endothelium. The sum of these effects produces activated inflammatory cells that are incapable of leaving the vasculature. As such, the endotoxic PMN is more likely to promote tissue injury from within microvascular beds than to clear pathogens from extravascular sites. Moreover, the functional characteristics of endotoxic PMNs are similar to those observed during trauma, burn injury, sepsis, surgery, and other inflammatory conditions. Accordingly, several clinical conditions might have a common effector in the activated, yet migratorially dysfunctional, PMN. Direct effects of endotoxin on PMNs as well as effects of endogenous mediators released during endotoxemia are discussed. Understanding PMN behavior during endotoxemia may provide basic and critical insights that can be applied to a number of inflammatory scenarios. J. Leukoc. Biol. 66: 10–24; 1999.
Induction of DAP12 phosphorylation, calcium mobilization, and cytokine secretion by Ly49H
Authors: Gosselin Pierre , Mason Llewellyn H , Willette-Brown Jami , Ortaldo John R , McVicar Daniel W , Anderson Stephen K 
Published: January 2018

Abstract
The ability of several Ly49 family members to inhibit natural killer (NK) cell functions through recruitment of SHP-1 phosphatase has been reported. In contrast, the mechanisms underlying the activating signal generated by Ly49D are poorly understood. A homodimeric phosphoprotein (pp16) that physically and functionally associates with Ly49D has been described. In this study, a rabbit anti-mouse pp16 antiserum was generated and used to demonstrate that pp16 corresponds to the recently described DAP12 molecule. In addition, we show that a second Ly49 family member that lacks an immunoreceptor tyrosine-based inhibitory motif and contains a charged residue in the transmembrane domain, Ly49H, also associates with DAP12. Furthermore, we show that engagement of the Ly49H/DAP12 complex results in phosphorylation of DAP12, intracellular calcium mobilization, and tumor necrosis factor secretion in transfected cells. These results thus provide evidence that Ly49H is an activating receptor that associates with DAP12, previously described as a pp16 component of the Ly49D receptor complex. J. Leukoc. Biol. 66: 165–171; 1999.
Hepatic dendritic cells: immunobiology and role in liver transplantation
Authors: Thomson A W , Drakes M L , Zahorchak A F , O'Connell P J , Steptoe R J , Qian S , Lu L 
Published: January 2018

Abstract
Traditional investigations of hepatic dendritic cells (DC) have focused on immunohistochemical studies of these cells within normal and pathological liver tissue. The recent availability of reagents for the improved characterization of DC, together with cytokine-based methods for the expansion of liver DC both in vivo and in vitro have begun to provide new insight into the immunobiology of these important antigen-presenting cells. Hepatic DC probably play a key role in the host response to blood-borne pathogens, and in the pathogenesis of infectious and autoimmune liver diseases. They appear to be important in determining the balance between liver transplant tolerance and rejection. Their possible role in oral and portal venous tolerance remains to be defined. In this article, we focus on emerging aspects of hepatic DC immunobiology, with particular reference to liver transplantation. J. Leukoc. Biol. 66: 322–330; 1999.
Regulation of the production of soluble IL-4 receptors in murine cutaneous leishmaniasis. The roles of IL-12 and IL-4
Authors: Fernandez-Botran Rafael , Chilton Paula M , Hondowicz Brian D , Vetvickova Jana , Yan Jun , Jones Walter , Scott Phillip 
Published: January 2018

Abstract
These studies were undertaken with the purpose of elucidating the key signals involved in the regulation of the production of soluble interleukin-4 receptors (sIL-4R) in mice during Th1 and Th2 responses to infection with the parasite Leishmania major. Our results showed that the production of sIL-4R was consistently higher in lymph node cell cultures from animals mounting a predominant Th2 response (BALB/c mice), and that sIL-4R production paralleled that of IL-4 in both mouse strains, even in the presence of a dominant Th1 response (C3H/FeJ mice). Consistently, administration of anti-IL-12 antibodies to infected C3H/FeJ mice induced a switch from a Th1- to a Th2-type response and resulted in enhanced production of sIL-4R. Addition of rIL-12 to splenic cell cultures, however, was found not to have a direct effect on sIL-4R production induced by IL-4 or T cell mitogens. Moreover, the production of sIL-4R appears to be little influenced by Th1-produced cytokines, inasmuch as recombinant interferon-γ or supernatants derived from antigen-stimulated Th1 clones did not affect the production of sIL-4R by activated splenic cultures. Despite its correlation with Th2 responses, the presence of IL-4 was not an absolute requirement for the up-regulation of the expression of sIL-4R because increased levels could be induced on cells obtained from IL-4−/− mice. These results indicate that, although enhanced sIL-4R production is a feature related to the activation and/or generation of Th2 responses, it is not absolutely dependent on IL-4 or directly inhibited by IL-12 or Th1 cytokines. J. Leukoc. Biol. 66: 481–488; 1999.
Inhibition of fMLP-triggered respiratory burst of human monocytes by adenosine: involvement of A3 adenosine receptor
Authors: Broussas Matthieu , Cornillet-Lefèbvre Pascale , Potron Gérard , Nguyen Philippe 
Published: January 2018

Abstract
Adenosine (Ado) is a potent anti-inflammatory agent acting on a variety of cell functions. However, its effects on human monocytes have been less well characterized. We investigated the effect of Ado and its receptor-specific analogs on NADPH oxidase activity with the use of luminol-enhanced chemiluminescence (CL). Adenosine inhibited fMLP-triggered NADPH oxidase activity with a maximal inhibition of 55 ± 5%. IB-MECA, a selective A3 Ado receptor agonist reduced fMLP triggered NADPH oxidase activity more potently than the A2 receptor agonist CGS 2180 HCl (CGS) and the A1 Ado receptor agonist N-2-phenylethyladenosine (R-PIA). The inhibitory effect of Ado was reversed by neither the A1 Ado receptor antagonist 1,3-dipropyl-8(2-amino-4chlorophenyl)-xanthine (PACPX) nor the A2 Ado receptor antagonist 3,7-dimethyl-1-(2-propynyl)xanthine (DMPX). It was significantly reversed by the A1/A3 Ado receptor antagonist xanthine amine congener (XAC). Pretreatment of monocytes by cytochalasin B reversed the effect of Ado but not of dibutyryl cAMP (dBcAMP) on fMLP-CL response. KT 5720, a specific cAMP-dependent protein kinase inhibitor completely counteracted the inhibition of NADPH oxidase activity by dBcAMP but not by Ado. Using flow cytometry, we observed that Ado did not inhibit intracellular oxidative metabolism, whereas dBcAMP did. Furthermore, the inhibition of NADPH oxidase activity by Ado was not mediated by changes in cytosolic calcium. These results demonstrated that Ado inhibited NADPH oxidase activity via A3 Ado receptor independently of cAMP elevation or changes in calcium mobilization. J. Leukoc. Biol. 66: 495–501; 1999.
Polarized expression of immunoglobulin, spectrin, and protein kinase C beta II occurs in B cells from normal BALB/c, autoimmune lpr, and anti-ssDNA transgenic, tolerant mice
Authors: Masso-Welch Patricia A , Black Jennifer D , Erikson Jan , Repasky Elizabeth A 
Published: January 2018

Abstract
The rapid redistribution of B cell surface immunoglobulin to a cap upon cross-linking treatment is a well-described phenomenon, the physiological significance of which is unknown. We describe the observation that splenic B cells from unimmunized normal, autoimmune, and tolerant mice express naturally occurring capped immunoglobulin in the absence of exogenous stimulation. The percentage of capped B cells increases to 20% of B cells by age 16 weeks in the progressive autoimmune lpr mouse. Transgenic, tolerant mice expressing lpr-derived genes for ssDNA-binding antibody also demonstrate a large percentage (35–75%) of immunoglobulin-capped splenic B cells. In these capped B cells, protein kinase C beta II, the cytoskeletal proteins spectrin and ankyrin, and the lipophilic probe diI are enriched beneath the site of the immunoglobulin cap. These data suggest that polarization of surface receptors, signaling molecules, anionic phospholipid domains, and cytoskeletal proteins may be an important part of the B cell immune response in vivo. J. Leukoc. Biol. 66: 617–624; 1999.
The transcription factor PU.1 does not regulate lineage commitment but has lineage-specific effects
Authors: McKercher Scott R , Henkel Gregory W , Maki Richard A 
Published: January 2018

Abstract
PU.1 is a transcription factor shown to regulate the expression of many important genes in myeloid and B cells. At birth, mice homozygous for the disruption of the PU.1 gene have erythrocytes, megakaryocytes, and T cells, but no mature myeloid or B cells. Cells with an inability to develop to maturity were found in this mouse for B cells, neutrophils, eosinophils, mast cells, and monocytes. Rescue of early monocytic cells by transfection with the PU.1 gene results in renewed development to macrophages. These results demonstrate that PU.1 is an important regulator in the development of cells in the hematopoietic system. J. Leukoc. Biol. 66: 727–732; 1999.
Macrophage apoptosis in mycobacterial infections
Authors: Fratazzi Candida , Arbeit Robert D , Carini Claudio , Balcewicz-Sablinska M Kasia , Keane Joe , Kornfeld Hardy , Remold Heinz G 
Published: January 2018

Abstract
Mycobacterial diseases are a major public health concern. In the case of tuberculosis, the problem has been acerbated due to the emergence of drug-resistant strains of Mycobacterium tuberculosis, and Mycobacterium avium is the major opportunistic pathogen in HIV-1 infection in the United States. M. tuberculosis and M. avium replicate in human macrophages and induce apoptosis. Incubation of freshly added uninfected autologous macrophages with apoptotic M. avium-infected macrophages results in 90% inhibition of bacterial growth. Apoptosis also prevents the release of intracellular components and the spread of mycobacterial infection by sequestering the pathogens within apoptotic bodies. Consistent with the model that host cell apoptosis is a defense mechanism against mycobacteria is the finding that the virulent M. tuberculosis strain H37Rv induces substantially less macrophage apoptosis than the attenuated strain H37Ra. Evasion of apoptosis by this pathogen is achieved by enhanced release of sTNFR2 by H37Rv-infected macrophages and subsequent formation of inactive TNF-α-TNFR2 complexes. These observations contribute to the hypothesis that apoptosis of the host macrophage is an important defense mechanism in mycobacterial infections, which prevents the spread of the infection. J. Leukoc. Biol. 66: 763–764; 1999.
CpG-oligodeoxynucleotide-resistant variant of WEHI 231 cells
Authors: Manzel Lori , Macfarlane Donald E 
Published: January 2018

Abstract
Bacterial DNA and synthetic single-stranded oligonucleotides having unmethylated CpG motifs (CpG-ODN) powerfully stimulate cellular immune responses by an unknown mechanism. There is evidence that internalization of the nucleotide is required for activity. Both CpG-ODN and engagement of CD40 protects WEHI-231 murine B lymphoma cells from apoptosis induced by antibody to surface IgM, and both agents induce interleukin-6 (IL-6) production by these cells. We now report the isolation of CpG-ODN-resistant subclones (designated CR) from WEHI 231 cells, as well as subclones that are sensitive to CpG-ODN (designated CS). CR clones completely fail to respond to CpG-ODN but they retain the capacity to respond normally to engagement of CD40. CR cells incorporate CpG-ODN into small, acidified perinuclear vesicles in the same way as do the parent WEHI 231 cells. The CR, CS, and WEHI 231 cells all had identical cytogenetics. The described CR clones have a stable and specific defect in the mechanism responsible for the intracellular recognition and response to CpG-ODN, suggesting that they harbor a mutation that disables the CpG-ODN detection mechanism. These clones may be useful to determine at a molecular level which proteins and cell components are required for immune cells to detect and respond to CpG-ODN. J. Leukoc. Biol. 66: 817–821; 1999.
Ethanol-induced neutrophil apoptosis is mediated through nitric oxide
Authors: Singhal Pravin C , Patel Puja , Nàhàr Nilay , Franki Nicholas , Kapasi Aditi , Reddy Krishna , Shah Neena , Nwakoby Izuchukwu E , Mehrotra Bhoomi 
Published: January 2018

Abstract
Clinical reports indicate that acute ethanol intoxication in chronic ethanol abusers is associated with neutropenia. We hypothesize that ethanol accelerates the apoptosis of neutrophils thus decreasing the peripheral blood count of neutrophils. We studied the effect of ethanol on neutrophil apoptosis in vivo as well as in vitro. Human neutrophils harvested from healthy subjects after an alcohol drinking binge showed enhanced apoptosis (before, 0.5 ± 0.25 vs. after, 26.1 ± 2.6% apoptotic neutrophils/field). Peritoneal neutrophils isolated from ethanol-treated rats also showed increased (P &lt; 0.0001) apoptosis when compared with neutrophils isolated from control rats (control, 0.8 ± 0.2% vs. ethanol, 11.8 ± 0.7% apoptotic neutrophils/field). In in vitro studies, ethanol in concentrations of 50 mM and higher accelerated the apoptosis of human and rat neutrophils. This effect of ethanol on human neutrophils was time dependent. DNA isolated from ethanol-treated human neutrophils displayed integer multiples of 180 base pairs (ladder pattern), further confirming the effect of ethanol on neutrophil apoptosis. NG-monomethyl-l-arginine monoac-etate and NG-nitro-L-arginine methyl ester, inhibitors of nitric oxide (NO) synthase, attenuated the ethanol-induced neutrophil apoptosis. Sodium nitroprusside, a NO donor, also promoted neutrophil apoptosis. Moreover, ethanol enhanced neutrophil expression of inducible NO synthase. In addition, ethanol stimulated neutrophil NO generation. These results suggest that ethanol accelerates neutrophil apoptosis. This effect of ethanol on neutrophil apoptosis seems to be mediated through the generation of NO. J. Leukoc. Biol. 66: 930–936; 1999.
Surface interleukin-10 inhibits listericidal activity by primary macrophages
Authors: Fleming Sherry D , Leenen Pieter J M , Freed John H , Campbell Priscilla A 
Published: January 2018

Abstract
Interleukin-10 (IL-10) down-regulates multiple functions of monocytes and macrophages, including the ability of macrophages to kill many intracellular microorganisms. The experiments presented here test the hypothesis that IL-10 expressed on the cell surface inhibits the ability of primary mouse macrophages to kill the facultative, intracellular bacterium Listeria monocytogenes. We show that, in contrast to macrophages from normal mice, both bone marrow-derived macrophages (BMDM) and thioglycollate-elicited macrophages obtained from IL-10−/− mice can kill L. monocytogenes. Treatment with anti-IL-10 monoclonal antibody (mAb) enables BMDM from normal mice and thioglycollate-elicited macrophages from RAG-2−/− mice (which lack T or B cell-derived IL-10) to kill L. monocytogenes, and concurrently down-regulates the expression of surface IL-10. Surface IL-10 on paraformaldehyde-fixed cells can inhibit nitric oxide (NO) production by interferon-γ (IFN-γ)-stimulated macrophages from IL-10−/− mice, thus directly showing functional activity of surface IL-10. Taken together, these studies indicate that macrophage surface IL-10 is biologically active and down-regulates macrophage bactericidal activity. J. Leukoc. Biol. 66: 961–967; 1999.
The murine chemokine receptor CXCR4 is tightly regulated during T cell development and activation
Authors: Schabath Richard , Müller Gerd , Schubel Andreas , Kremmer Elisabeth , Lipp Martin , Förster Reinhold 
Published: January 2018

Abstract
We have characterized the murine homolog of the HIV-co-receptor CXCR4 during T cell development and activation. Our data demonstrate that this chemokine receptor, although highly conserved between human and mouse, is differently expressed and regulated in both species. Mitogenic activation resulted in an increase of surface CXCR4 on murine T cells within 2 days, whereas the receptor was strongly down-regulated on human T cells during this period. Furthermore, intraperitoneal immunization of mice resulted in a strong increase of splenic and mesenteric cytotoxic T cells co-expressing CXCR4. It is interesting that, on thymocytes, expression of CXCR4 is restricted to CD4+CD8+ cells. Stromal cell-derived factor-1α, a natural ligand of CXCR4, induced chemotaxis of thymocytes and was found to counteract dexamethasone-induced apoptosis to a certain extent in these cells. Thus, our data show that expression of CXCR4 is tightly controlled on murine T cells and indicate that this highly conserved chemokine receptor might serve different functions in humans and mice. J. Leukoc. Biol. 66: 996–1004; 1999.
Interaction of various intracellular signaling mechanisms involved in mononuclear phagocyte toxicity toward neuronal cells
Authors: Klegeris Andis , McGeer Patrick L 
Published: January 2018

Abstract
Microglia become activated in a wide range of neurodegenerative disorders, including Alzheimer's disease. Such activation may lead to autodestruction of neurons. It is demonstrated here that activation of both human microglia and monocytic THP-1 cells by a combination of lipopolysaccharide and interferon-γ results in secretion of neurotoxins that kill human neuronal SH-SY5Y cells. This neurotoxicity can be partially blocked by inhibitors of cytosolic phospholipase A2, cGMP-selective phosphodiesterases, or protein kinase C. When combinations of these inhibitors, or combinations of an inhibitor plus nordihydroguaiaretic acid, or the nonsteroidal anti-inflammatory drug diclofenac were tried, additive reductions in neurotoxicity were observed. It is concluded that the stimulants activated multiple intracellular pathways, and that combination therapies inhibiting these pathways might be beneficial for treating neurodegenerative disorders. J. Leukoc. Biol. 67:127–133; 2000.