bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunolocalization of Endosomal Cathepsin D in Rabbit Alveolar Macrophages
Authors: Rodman Jane Somsel , Levy Marilyn Aach , Diment Stephanie , Stahl Philip D 
Published: January 2018

Abstract
Intravacuolar proteolysis appears to be an important component of antigen presentation, the activation of peptide hormones, and the conversion of biologically important mediators from inactive precursors. Cathepsin D has been identified in the endosomes of rabbit alveolar macrophages by biochemical analyses [Diment and Stahl, J. Biol. Chem. 260, 15311, 1985; Diment et al., J. Biol. Chem. 263,6901, 1988]. Using affinity-purified goat antirabbit cathepsin D IgG, we have localized cathepsin D to the endosomes of rabbit alveolar macrophages. Immunofluorescent staining of frozen sections showed labeling in lysosomes and small vesicles in the periphery of the cell. Label was not seen on the plasma membrane. With immunoperoxidase labeling at the electron microscopic level on cells containing endocytosed mannose-BSA gold, we saw labeling in endosomes and classical lysosomes. When the results were quantrtated using immunogold labeling of thin cryosections, we found that the majority of cathepsin D (62.2%) was present in lysosomes, 4.0% in large clear vacuoles, a surprisingly high percentage (29.3%) in small vesicles, 4.9% in endosomes, and none on the plasma membrane. We conclude from this study that, in addition to being present in lysosomes, cathepsin D is present in endosomes and in small peripheral vesicles.
Uncoupling of Oxidative and Non-Oxidative Mechanisms in Human Granulocyte-Mediated Cytotoxicity: Use of Cytoplasts and Cells From Chronic Granulomatous Disease Patient
Authors: van Kessel Kok P M , van Strijp Jos A G , van Kats-Renaud Henny J , Miltenburg Lia A M , Fluit Ad C , Verhoef Jan 
Published: January 2018

Abstract
Human polymorphonuclear leukocytes (PMN) and granule-free cytoplasts were compared for their cytotoxic capacities against red blood cells (RBC) and K562 tumor cells. Phorbol myristate acetate (PMA) stimulated PMN to efficient lysis of RBC targets, while cytotoxicity against the tumor cell line K562 was moderate. Activated cytoplasts also lysed RBC targets but were not able to kill K562 tumor cells, even at high cell numbers. Suppression of the glutathione redox cycle of the K562 tumor targets markedly increased their susceptibility to lysis by PMA-activated PMN. Despite the enhanced susceptibility of antioxidant-depleted K562 tumor cells to oxygen radical-induced damage, PMA-stimulated cytoplasts did not kill these targets. Addition of exogenous myeloperoxidase or lactoferrin to cytoplasts devoid of granule did not improve the lysis of RBC and K562 tumor cells. Coating K562 targets with specific antibodies induced efficient PMN-mediated killing in comparison to PMA-stimulated lysis of non-coated targets. Cytoplasts, however, did not kill antibody-coated K562 tumor cells; this was not improved by glutathione depletion but showed some lysis of antibody-coated RBC. PMN from a patient with chronic granulomatous disease (CGD) showed normal antibody-dependent cell-mediated cytotoxicity (ADCC) against K562 tumor cells but were not able to lyse these targets after PMA stimulation. The analysis of target cell killing by cytoplasts and PMN from a CGD patient indicated that granular constituents are important mediators in the killing of nucleated target cells and that PMN-mediated ADCC does not require the release of reactive oxygen species. Differences in the susceptibility of target cells to oxygen-mediated lysis indicates that target cell antioxidant mechanisms play an important role in the outcome of the cytotoxic response.
Prostaglandin-Dependent Desensitization of Human Monocyte cAMP Responses
Authors: Coffey Ronald G , Alberts Vicki A , Weakland Laura L 
Published: January 2018

Abstract
Histamine stimulated large increases of cyclic adenosine monophosphate (cAMP) in freshly isolated human blood monocytes in the presence of RO2-1724, a specific cAMP phosphodiesterase inhibitor. This was mediated by H2 receptors, since it was inhibited by cimetidine but not chlorpheniramine. Stimulation was attenuated in cells aged in culture 1–2 days. Indomethacin prevented the desensitization, suggesting that a cyclooxygenase product was responsible. Desensitization was heterologous, since the adenylate cyclase responses to 5′-(N-ethylcarboxamido)adenosine (A2 receptor agonist), isoproterenol (β-adrenoceptor agonist), and prostaglandin E2 (PGE2) also declined during culture. The loss of sensitivity to histamine was restored by incubating monocytes with PGE2 in the presence of indomethacin. The results indicate that, while PGE2 inhibits monocyte functions via cAMP, its accumulation paradoxically permits cells to escape this regulation through a heterologous desensitization of the cAMP response to itself and other agonists.
Differentiation of Rat Bone Marrow Cells Into Macrophages Under the Influence of Mouse L929 Cell Supernatant
Authors: Naum Chris C , Kaplan Sandra S , Basford R E 
Published: January 2018

Abstract
Platelets are currently thought to play a role in tissue injury and inflammatory states both directly and indirectly through their action on neutrophils (PMNs). Both stimulation and inhibition of PMN superoxide anion (O2-) production by platelets has been reported. To clarify these discrepant observations, we investigated the effects of wide ranges of platelet to PMN ratios as well as concentrations of ATP and ADP on human PMN O2- production. Platelets, at low platelet-to-PMN ratios (1:1 and 5:1), primed PMNs which were stimulated with either FMLP or PMA. However, at higher platelet-to-PMN ratios (25:1, 50:1, and 100:1), inhibition of O2- production was seen. ATP also had a biphasic effect on O2- production: low concentrations of ATP (1 x 10-6 to 3.2 x 10-4 M) increased O2 production and high concentrations of ATP (6.4 x 10-4 M and above) inhibited O2 production. ADP, when added to stimulatory concentrations of ATP, also caused inhibition of O2- production. The incubation time for platelet-neutrophil interactions in vitro was also crucial. Short incubation periods lead to priming, whereas longer periods (&gt; 5 min) lead to inhibition. We believe that these studies help to resolve the controversy over the effects of platelets upon the production of O2- by human PMNs and lend further support to the notion that platelets may modulate injury resulting from neutrophil activation.
High-Affinity Receptor for Interferon-Gamma (IFN-γ), a Ubiquitous Protein Occurring in Different Molecular Forms on Human Cells: Blood Monocytes and Eleven Different Cell Lines Have the Same IFN-γ Receptor Protein
Authors: van Loon Adolphus P G M , Ozmen Laurence , Fountoulakis Michael , Kania Malgosia , Haiker Monika , Garotta Gianni 
Published: January 2018

Abstract
High-affinity receptors for human IFN-γ were analyzed using 13 different cells, including blood monocytes. Scatchard analysis showed one high-affinity binding site for each cell. One cross-linked complex between IFN-γ and the receptor was detected, although their apparent molecular masses were variable in different cells, as also confirmed in immunoblots of membrane extracts. Variations in molecular masses were abolished if N-linked glycosylation was absent. Stable tryptic fragments contained the intact binding site for IFN-γ and antibody epitopes characteristic of the extracellular domain of the IFN-γ receptor of Raji cells and were of different sizes only if glycosylated. In addition, Northern analysis showed the same mRNA encoding the high-affinity IFN-γ receptor in each cell analyzed. Thus, all cells including blood monocytes express the same high-affinity IFN-γ receptor protein. N-linked sugars may give structural stability to the IFN-γ receptor and are unlikely to be directly involved in IFN-γ binding.
Isolation and Flow Cytometric Characterization of Newborn Mouse Brain-Derived Microglia Maintained In Vitro
Authors: Hassan Nassef F , Rifat Salahaldin , Campbell Donald E , McCawley Lisa J , Douglas Steven D 
Published: January 2018

Abstract
Microglia have been identified in the white matter of developing and adult mouse brain using different murine macrophage markers. While several techniques for the isolation of murine microglia have been described, the small cell yields and partial purification have limited the progress of these studies. We now describe the isolation of murine microglia using a modification of McCarthy and de Vellis method. Brain tissues from 1–2 day old newborn mice were mechanically and chemically dissociated and maintained in in vitro culture for 3 weeks. In primary dissociated brain cultures, microglia are observed after 10 days migrating from small colonies. After 16–20 days, brain-derived microglia were isolated with high cell yields by continuous shaking of the cultures for 16 hr. In contrast to resident murine peritoneal macrophages, microglia express less Class II (la) antigen and a small percentage express L3T4 (CD4) antigen by flow cytometry.
Poly I:C-Induced Anti-Herpes Simplex Virus Type 1 Activity in Inflammatory Macrophages Is Mediated by Induction of Interferon-β
Authors: Pyo S , Gangemi J D , Ghaffar A , Mayer E P 
Published: January 2018

Abstract
We examined the mechanism by which Polyriboinosinic:Polyribocytidylic acid (Poly l:C) augments resistance of thioglycolate-elicited inflammatory macrophages to infection with herpes simplex virus type 1 (HSV-1). We show that Poly l:C-induced antiviral activity is completely abrogated by antibodies to interferon-β (IFN-β) whereas antibodies to other interferons or to other cytokines have no effect. Furthermore, treatment of inflammatory macrophages with exogenous IFN renders them resistant to HSV-1, whereas treatment with other cytokines does not. In addition, we demonstrate that supernatants from macrophages treated with Poly l:C contain IFN-β but not IFN-α. Taken together these data indicate that the antiviral effects of Poly l:C in inflammatory macrophages are mediated solely by IFN-β, which acts in an autocrine manner to induce resistance to HSV-1.
Selective Secretion of Azurophil Granule Contents Induced by Monovalent Cation Ionophores in Human Neutrophils: Evidence for Direct Ionophore Effects on the Granule Membrane
Authors: Fittschen Claus , Henson Peter M 
Published: January 2018

Abstract
The study of factors contributing to secretion of neutrophil azurophil granules has previously been complicated by the inability to induce their release without concomitant exocytosis of specific granules. This publication describes the action of the first two agents, the Na-ionophore monensin and the K-ionophore nigericin which elicited only secretion of azurophil granules. Secretion depended on H+/alkali ion antiport by the ionophores since it was abolished in Na+- and K+-poor choline buffer. The secretagogue effects of both ionophores did not correlate with changes either in cytoplasmic pH or in transmembrane potential and were not associated with Ca-transients, but were closely associated with azurophil granule alkalinization suggesting that the secretory event resulted from alkali ion/H+ antiport at the granule membrane. Addition of zinc inhibited azurophil (but not specific) granule secretion in response to monensin, CB/FMLP, and zymosan, indicating that secretion induced by these agents shares a common step(s).
Induction of Tumor Necrosis Factor and Macrophage-Mediated Cytotoxicity by Horseradish Peroxidase and Other Glycosylated Proteins: The Role of Enzymatic Activity and LPS
Authors: Lefkowitz Doris L , Mills Kevin , Castro Aaron , Lefkowitz Stanley S 
Published: January 2018

Abstract
Recent studies by these investigators have shown that horseradish peroxidase (HRP) can cause murine thioglycollate-induced peritoneal macrophages (Mø) to produce both tumor necrosis factor (TNF) and enhance macrophage-mediated cytotoxicity (MMC) to 3T12 target cells. The present study identifies the roles of both enzymatic activity and contaminating lipopolysacharides (LPS) (≤1 ng) on these activities. The addition of 100 ng/ml of polymyxin B (PB) to enzymatically active HRP significantly reduced TNF production but did not affect MMC. Enzymatically inactive HRP (DHRP) was more effective than HRP in both TNF production and MMC but was not affected by PB. The inability of PB to modify DHRP-induced TNF suggests that LPS was not required. The induction of TNF and MMC in the absence of LPS was also corroborated by similar studies using Mø from endotoxin-resistant C3H/HeJ mice. Glycosylated proteins such as HRP, DHRP, and mannosylated bovine serum albumin (M-BSA) are known to bind to mannose receptors (mannosyl-fucosyl receptor [MFR]) on the surface of Mø. In the present studies, M-BSA behaved similarly to DHRP in that it induced both TNF secretion and MMC. These results suggest that binding to the MFR may be sufficient to induce TNF secretion and MMC. In addition, the data suggest that neither enzymatic activity nor LPS was required for DHRP-induced TNF.
Cryopreserved Cytoplasts From Human Neutrophils Migrate Across Monolayers of Human Endothelial Cells in Response to a Chemoattractant Gradient
Authors: Huang Ada J , Silverstein Samuel C , Malawista Stephen E 
Published: January 2018

Abstract
We have measured the capacity of two types of granule-poor anucleate cytoplasmic fragments (cytoplasts) from human polymorphonuclear leukocytes (PMN) to migrate across the barrier imposed by monolayers of human umbilical vein endothelial cells (EC) with and without chemotactic stimulation by fMLP. Cytoplasts were made by brief heating of PMN attached to surfaces (CKP) or by discontinuous gradient centrifugation (U-CYT). In the absence of chemoattractant, both types of cytoplast adhered poorly to endothelial cell monolayers, as did unstimulated intact PMN from which the cytoplasts were derived. In the presence of a transendothelial chemoattractant gradient both types of cytoplast exhibited a marked increase in adherence to, and migration across, endothelial monolayers; CKP did so to the same extent as chemoattractant-stimulated intact PMN. Since these motile cytoplasts are markedly deficient in most cytoplasmic organelles they may serve as useful tools for the dissection of cellular mechanisms that mediate PMN migration across endothelia.
Evidence for the involvement of tyrosine kinases in the locomotory responses of human neutrophils
Authors: Gaudry Murielle , Caon Adriana C , Gilbert Caroline , Lille Simonne , Naccache Paul H 
Published: January 2018

Abstract
Erbstatin, a recently described inhibitor of tyrosine kinases, has been used to examine the potential role of tyrosine phosphorylation in human neutrophil locomotion. Preincubation of human neutrophils with erbstatin inhibited both spontaneous and directed migration induced by chemotactic factors such as formyl-methionylleucylphenylalanine (fMet-Leu-Phe) and leukotriene B4. The decreased migratory responses were correlated with an inhibition of adherence of neutrophils to serum-coated surfaces. Erbstatin did not, however, affect the adherence of human neutrophils to uncoated surfaces. These results indicated that the inhibitory effects of erbstatin were specific and not due to a generalized alteration of the surface of human neutrophils. To elucidate the mechanism of the inhibitory effect of erbstatin on adherence properties, the expression of the leukocyte integrin Mo1 was studied. Erbstatin induced a small but significant increase in the expression of Mo1, but decreased the stimulation of the expression of Mo1 elicited by fMet-Leu-Phe. These results suggest that mechanisms in addition to alteration of the number of surface integrins are involved in the inhibition of neutrophil adherence and locomotion by erbstatin. J. Leukoc. Biol. 51: 103–108; 1992.
Effects of in vivo T lymphocyte subset depletion on mycobacterial infections in mice
Authors: Flory Craig M , Hubbard Randall D , Collins Frank M 
Published: January 2018

Abstract
The relative importance of CD4+ and CD8+ T cell subsets in the expression of acquired resistance to systemic infection by Mycobacterium kansasii was determined. T cell subsets were depleted in thymectomized C57BL/6 mice by the intravenous administration of monoclonal antibodies directed against the relevant T cell determinants. Depletion of the CD4+ subset exacerbated the severity of the infection in intravenously challenged mice. This effect was apparent in the first 2 weeks of the infection and persisted throughout the 12 weeks of the study. On the other hand, depletion of the CD8+ cells had no apparent effect on the growth curves. Infections by Mycobacterium tuberculosis Erdman or bacille Calmette-Guérin (BCG) Pasteur were also substantially enhanced by CD4 depletion, but not by the depletion of CD8+ cells. The effect of subset depletion on infections by M. tuberculosis and BCG was examined in both innately susceptible C57BL/6 mice and innately resistant B6D2 mice.
The timing of exposure of mononuclear phagocytes to recombinant interferon γ and recombinant tumor necrosis factor α alters interactions with Nocardia asteroides
Authors: Beaman LoVelle , Beaman Blaine 
Published: January 2018

Abstract
Nocardia asteroides modulates phagocyte function and grows within macrophages. Because interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) have been shown to activate macrophages to kill a variety of microorganisms, the effects of IFN-γ and TNF-α on the activation of murine macrophages and human monocytes to kill nocardiae were studied. It was found that macrophages or monocytes treated with either IFN-γ, TNF-α, or lipopolysaccharide as a secondary signal did not demonstrate increased microbicidal activity against N. asteroides even though these phagocytes were effective at killing the fungus Coccidioides immitis and the protozoan Toxoplasma gondii. Preincubation of phagocytes for 24 h with these compounds resulted in an enhancement of nocardial growth. In contrast, coincubation of these factors with the nocardiae and mononuclear cells during phagocytosis resulted in inhibition of nocardial growth even though this bacterium was not killed. Therefore, the specific timing of the exposure of the phagocyte in vitro to IFN-γ or TNF-α has a significant effect on its ability to alter nocardial growth.
Mouse macrophages contain a truncated CD4 transcript
Authors: Moore Steven C , Anderson Stephen J , Walker William S 
Published: January 2018

Abstract
Mouse macrophages do not express CD4 on their surfaces. We used the polymerase chain reaction to investigate CD4 gene transcription in individual clones of primary mouse splenic macrophages and cell lines of spleen and bone marrow macrophages. The results show only the presence of CD4 mRNA transcripts that are truncated in the 3′ coding sequence, thus explaining the lack of expression of a mature CD4 gene product by these cells.
Interleukin-6 in mouse hypersensitivity pneumonitis: changes in lung free cells following depletion of endogenous IL-6 or direct administration of IL-6
Authors: Denis Michel 
Published: January 2018

Abstract
In this study, we examined the role of interleukin-6 (IL-6) in the development of chronic lung inflammatory conditions, using a mouse model of hypersensitivity pneumonitis established by intranasal instillation of the thermophilic actinomycete Faeni rectivirgula. Challenged mice developed an early neutrophilic response at 24 h, followed by a macrophage/lymphocyte recruitment. The impact of IL-6 on the development of the inflammatory response was assessed by giving infusions of a monoclonal antibody against IL-6 so as to deplete endogenous levels of this cytokine or by giving exogenous IL-6 to challenged mice. Mice challenged in-tranasally with the actinomycete and given the anti–IL-6 antibody developed a strong, sustained neutrophilic response, with a significantly higher lung free cell number than control mice. Assessment of fibrosis by measuring lung hydroxyproline levels showed that challenged mice given anti–IL-6 developed more significant fibrosis than control mice. Conversely, infusions with IL-6 diminished F. rectivirgula–induccd cell recruitments and the fibrotic response in the lungs. Moreover, alveolar macrophages from mice given 2 weeks of F. rectivirgula treatment released high levels of tumor necrosis factor a (TNF-α) bioactivity upon in vitro lipopolysaccharide challenge, compared to mice instilled with saline only. This TNF-α activity produced by macrophages was decreased by in vivo IL-6 treatment and enhanced by in vivo neutralization with anti-IL-6. These observations suggest that IL-6 may play a role in regulating the cellular recruitment in the lungs during an inflammatory response, with dramatic consequences for the cellular profile in the bronchoalveolar lavage and the subsequent fibrosis.
Heterogeneity of rat liver and spleen macrophages in gadolinium chloride–induced elimination and repopulation
Authors: Hardonk MJ , Dijkhuis FWJ , Hulstaert CE , Koudstaal J 
Published: January 2018

Abstract
Blockade of phagocytosis and selective elimination of macrophages (mφs) are generally accepted procedures for gaining knowledge about the function of mφs in vivo. This study demonstrates that intravenous injection of gadolinium chloride (GdCl3) not only blocks phagocytosis by rat liver mφs (Kupffer cells) but also selectively eliminates the large mφs situated in the periportal zone of the liver acinus. Repopulation of mφs starts at 4 days after injection. During repopulation, mφs are less vulnerable to GdCl3. When repopulation is complete, the new mφs show the same vulnerability as the original ones. Splenic mφs are less vulnerable to GdCl3 because only some of the red pulp mφs transiently disappear. The white pulp mφs are not affected. Repopulation occurs sooner than in liver. These results indicate that administration of GdCl3 is a suitable approach to studying the in vivo function of large Kupffer cells.
Activation of tumoricidal properties in macrophages by lipopolysaccharide requires protein-tyrosine kinase activity
Authors: Dong Zhongyun , O’Brian Catherine A , Fidler Isaiah J 
Published: January 2018

Abstract
The purpose of these studies was to determine whether triggering murine peritoneal macrophages to a tumoricidal state by lipopolysaccharide (LPS) requires protein-tyrosine phosphorylation. The LPS-triggered activation of mouse macrophages to lyse syngeneic B16 melanoma cells was significantly inhibited in a dose- dependent manner by the protein-tyrosine kinase (PTK) inhibitors genistein, herbimycin A, and tyrphostin. Genistein was effective only when added to macrophages prior to or simultaneously with LPS. Genistein potently inhibited the productive interaction of macrophages with LPS but had only a minor effect on the action of interferon- γ. The effects of genistein on LPS-triggered macrophage activation were not due to nonspecific changes in macrophage metabolism or toxicity because genistein did not prevent lysis of tumor cells by activated macrophages, nor did it reduce the capacity of macrophages to phagocytose antibody-opsonized sheep erythrocytes. Western blot analysis with antiphosphotyrosine monoclonal antibody revealed that incubation of macrophages with LPS produced a rapid increase in tyrosine phosphorylation of several proteins and that the induced phosphorylation could be inhibited by effective concentrations of genistein, herbimycin A, or tyrphostin. Taken together, these data indicate that protein-tyrosine phosphorylation plays an important role in LPS-induced tumoricidal activation of macrophages. J. Leukoc. Biol. 53: 53–60; 1993.