bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guinea Pig Lung Eosinophil: Purification and Prostaglandin Production
Authors: Hirata K , Pelé J P , Robidoux C , Sirois P 
Published: January 2018

Abstract
Guinea pig lung eosinophils have been purified from bronchoalveolar lavage (BAL) fluid, and the production of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto-PGF1α was measured after stimulation with phorbol myrlstate acetate (PMA), platelet-activating factor (PAF), and formyl-methionyl-leucyl-phenylalanine (fMLP). A combination of plating and discontinuous Percoll gradient centrifugation was used to purify eosinophils. The purity of eosinophils in fraction E (interface between Percoll density 1.057-1.068) was around 96%, and the viability was 99%, with a mean yield of 2.7 × 106 cells per guinea pig. Similarly, in fraction D (interface between Percoll density 1.047-1.057), the mean purity of eosinophils was 76% and the viability of cells was 99%, with a mean yield of 1.1 × 106 cells per guinea pig. Purified eosinophils produced TXB2 predominantly after stimulation with PMA, fMLP, and PAF. The 6-keto-PGF1α was slightly increased in cell supematants after stimulation with PMA and fMLP, but PGE2 was not elevated with any stimulus. The highly purified eosinophils of fraction E generated amounts of TXB2 and 6-keto-PGF1α similar to the amount generated by eosinophils contaminated with some macrophages (fraction D). These results suggest a role for eosinophils in the production of TXA2 by guinea pig lung.
Downregulation of Tumor Necrosis Factor Expression in the Human Mono-Mac-6 Cell Line by Lipopolysaccharide
Authors: Haas Jürgen G , Thiel Corinna , Blömer Kathi , Weiss Elisabeth H , Riethmüller Gert , Löms Ziegler-Heitbrock H W 
Published: January 2018

Abstract
Mono-Mac-6 cells, but not U937 cells, can be induced to rapidly express tumor necrosis factor (TNF) mRNA and protein when triggered with lipopolysaccharide (LPS) at 1 μg/ml. Preincubation of the cells for 3 d with low amounts of LPS (10 ng/ml) results in nearly complete suppression of TNF secretion. This downregulation appears to occur at the pretranslational level since specific mRNA is virtually undetectable under these conditions. By contrast, the same preincubation with 10 ng/ml LPS results in enhanced phagocytosis (28.6-67.2% for Staphylococcus aureus), demonstrating that not all monocyte functions are suppressed. While these results show that only stringent exclusion of LPS from culture media allows for induction of TNF in the Mono-Mac-6 cell line, the pronounced effect of LPS preincubation may also provide a suitable model with which to study the mechanisms of LPS-induced desensitization.
Human Sera and Culture Supernatants From Human Tumors and Diploid Fetal Fibroblasts Suppress Tumor Necrosis Factor Secretion In Vitro
Authors: Scuderi Philip , Rippe Richard A , Raitano Arthur B , Rybski James 
Published: January 2018

Abstract
Human sera and culture supernatants from human tumors and diploid fetal fibroblasts suppressed peripheral blood leukocyte secretion of tumor necrosis factor (TNF). The suppressive activities of all three fluids had similar characteristics: each was heat and acid stable, removed by adsorption on immobilized lectins, and abrogated the stimulatory effect of interferon-γ. Inhibition of leukocyte TNF secretion was observed only when either serum or conditioned medium was added to leukocytes at the initiation of culture; delaying the addition by 2 h failed to suppress cytokine secretion. Suppression by all fluids was also found to be reversible by washing cells free of suppressive activity. Although serum, tumor, and fibroblast culture supernatants inhibited cytokine secretion, they failed to alter the cytotoxic activity of recombinant human TNF on murine L929 cells. This study suggests that factors which can inhibit TNF secretion are present in human blood and are secreted by both fibroblasts and tumor cells. These suppressive factors may play an important role in the regulation of TNF secretion and cytokine homeostasis.
Effect of Granulocyte-Macrophage Colony-Stimulating Factor on Superoxide Production in Cytoplasts and Intact Human Neutrophils: Role of Protein Kinase and G-Proteins
Authors: Mege Jean-Louis , Gomez-Cambronero Julian , Molski Thaddeus F P , Becker Elmer L , Sha'afi Ramadan I 
Published: January 2018

Abstract
Granulocyte-macrophage colony-stimulating factor, GM-CSF, potentiates superoxide generation produced by human neutrophils stimulated with fMet-Leu-Phe and platelet-activating factor, PAF, but not by phorbol 12-myristate 13-acetate (PMA) or opsonized zymosan. The potentiation is greatest in fMet-Leu-Phe-stimulated cells. This indicates that the actions of only certain receptors are potentiated by GM-CSF. Incubation of the cells with the protein kinase inhibitor H-7 or with the protein synthesis inhibitor cyclohexamide before the addition of GM-CSF does not affect the observed potentiation. The rationales behind these studies are to examine the roles of protein kinase C and protein synthesis in the action of GM-CSF. The data suggest that neither protein kinase C nor protein synthesis is necessary for GM-CSF action. On the other hand, no potentiation can be seen in the presence of cytochalasin B. Unlike intact cells, GM-CSF does not enhance superoxide production by cytoplasts stimulated with fMet-Leu-Phe. The rationale behind the use of cytoplasts is to examine the role of granules and/or nucleus in GM-CSF action, and the data indicate that one or more of these two components is necessary for the priming effect of GM-CSF. The amount of actin associated with the cytoskeleton under control or fMet-Leu-Phe-stimulated condition is the same in normal and GM-CSF-treated human neutrophils. Botulinum D toxin ADP-ribosylates a protein with a moleuclar weight of 22 kDa This ribosylation is reduced in homogenates obtained from cells pretreated with botulinum D toxin or GM-CSF. Botulinum D toxin does not affect the basal or the fMet-Leu-Phe-induced rise in the intracellular concentration of free calcium in human neutrophils. GM-CSF also increases the rise in intracellular concentration of free calcium in human neutrophils stimulated with PAF or fMet-Leu-Phe. The increases are inhibited by petussis toxin, Several important conclusion can be drawn from these data. 1) GM-CSF potentiates the rise in Ca2+, produced by PAF and fMet-Leu-Phe, and these potentiations are inhibited in pertussis-toxin-treated cells. 2) GM-CSF does not prime cytoplasts to stimulation by fMet-Leu-Phe. This suggests that the granules and/or nucleus are necessary for the priming action. 3) The priming by GM-CSF is not mediated by the H-7-sensitive protein kinase C, botulinum D-sensitive G-protein, or protein synthesis.
Monoclonal Antibodies (G1.4, D7.5) Induce Secretion of Lytic Factors From Natural Killer and T Lymphocytes
Authors: Stein-Streilein Joan , Guffee Judy 
Published: January 2018

Abstract
Monoclonal antibodies were made by standard procedures using mononuclear cells isolated from hamster lung tissue to immunize the mice. The Moabs (G1.4, D7.5), secreted by the selected hybridomas, were isotyped as IgG2a Kappa and were lytic in the presence of complement for 20% lymphocytes from lymph nodes or lung tissue; 40-50% of lymphocytes from spleen or bone marrow; and 70-80% of thymocytes or nylon wool nonadherent lung or lymph node lymphocytes. Functional studies showed that prior incubation of either Moab with enriched natural killer (NK) and T lymphocyte subpopulations did not interfere with effector: target conjugate formation but did block the ability of the effector cells to lyse NK-sensitive targets. We conclude that the Moabs bind to a molecule(s) on NK and T lymphocytes. Further, the preincubation medium acquired the capacity to lyse preferentially NK-sensitive targets but not NK-lnsensitive targets. Interestingly, the Moabs were able to induce secretion of lytic factors from thymocytes and to induce resting peripheral T lymphocytes to acquire NK activity and release lytic factors. The ability of the Moab to signal release of lytic factors was retained even when monovalent Fab fragments were used; therefore, the Moabs initiate secretion by mechanisms that do not apparently involve crosslinking or Fc receptor interaction. G1.4 and D7.5 Moabs were functionally and antigenically crossreactive with human, rat, and hamster lymphocytes but not with mouse lymphocytes. Biochemical and immunochemical analysis showed that the G1.4 and D7.5 antigen on thymus cells and lung mononuclear cells has an apparent molecular weight of 27 kD. Although it is unlikely that there is an universal mechanism for secretion used by cells in general, it is interesting that Moab treatment of three different subpopulation of lymphocytes induced secretion of lytic factors and suggests that under physiologic conditions a common molecule might participate in induction of the secretion pathway. These studies lead to the hypotheses that 1) NK and T lymphocytes share a cell surface molecule that participates in signals that initiate secretion and that 2) the expression of the G1.4, D7.5 antigens precedes thymic differentiation.
Dexamethasone Modulation of In Vivo Effects of Endotoxin, Tumor Necrosis Factor, and Interleukin-1 on Liver Cytochrome P-450, Plasma Fibrinogen, and Serum Iron
Authors: Bertini Riccardo , Bianchi Marina , Erroi Annalaura , Villa Pia , Ghezzi Pietro 
Published: January 2018

Abstract
Treatment of mice with endotoxin (lipopolysaccharide, LPS) and the two LPS-induced monokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1), caused a depression of liver cytochrome P-450 and related drug-metabolizing enzymes, as well as other acute-phase changes including increase in plasma fibrinogen levels and hypoferremia. However, only IL-1, not TNF or LPS, depressed cytochrome P-450 in cultured hepatocytes, suggesting that the effect of TNF in vivo might be mediated by a second mediator. TNF-or LPS-stimulated monocytes released a factor capable of depressing cytochrome P-450 in cultured hepatocytes. This factor was inhibited by anti-IL-1 antiserum, and its synthesis, like that of IL-1, was inhibited by dexamethasone (DEX). Pretreatment of mice with DEX protected against the depression of liver cytochrome P-450 by LPS or TNF but not by IL-1, suggesting that IL-1 directly depresses cytochrome P-450 and that DEX acts by inhibiting IL-1 synthesis in vivo induced by LPS or TNF. However, DEX did not inhibit two other effects of LPS and TNF in vivo: increase of plasma fibrinogen levels and decrease of plasma iron, suggesting that these might not be mediated by IL-1. Therefore, the effect of DEX in vivo, although supporting the hypothesis that depression of liver cytochrome P-450 by LPS and TNF is mediated by IL-1, indicates the existence of IL-1-independent pathways in the acute-phase response.
Phagocytosis and Killing of Cryptococcus neoformans by Rat Alveolar Macrophages in the Absence of Serum
Authors: Bolaños Benjamin , Mitchell Thomas G 
Published: January 2018

Abstract
The in vitro interaction between yeast cells of Cryptococcus neoformans and Lewis rat alveolar macrophages (AMÕ) was studied in the absence of serum. AMÕ were harvested by lung lavage, and monolayers of adherent cells were established in wells of microtiter plates. Radiolabeled yeast cells were added to fresh AMÕ monolayers, the plates were incubated at 37°C under 5% CO2, nonadherent yeasts were removed, and phagocytosis (i.e., attachment or ingestion) was determined by measuring adherent radioactivity. AMÕ were able to bind or ingest, and kill, encapsulated strains of C. neoformans in the absence of serum. Serum-free phagocytosis was suboptimal by comparison with phagocytosis in the presence of serum. The mechanism of serum-free phagocytosis Involves a receptor on the AMÕ with affinity for mannose-rich determinants present on the yeast cell walls and unrelated to the capsular polysaccharide. Opsonin-independent phagocytosis was only detected with nonencapsulated, small, and medium encapsulated strains of C. neoformans. Large encapsulated strains were not taken up without serum. Serum-free phagocytosis could be of critical importance in the alveolar spaces, where only marginal concentrations of serum opsonins are initially present.
Characterization of the Interaction Between Recombinant Human lnterferon-γ and Its Receptor on Human Polymorphonuclear Leukocytes
Authors: Hansen Brian D , Finbloom David S 
Published: January 2018

Abstract
The interaction of human recombinant interferon-γ (rlFN-γ) with human polymorphonuclear cells (PMN) was investigated. Bolton-Hunter radioiodinated rlFN-γ bound to PMN in a specific and saturable manner. Eleven hundred binding sites were observed with a Ka of 0.56 x 1010 M-1. Binding to PMN was rapid with a K1 of 9 x 105 M-1 sec-1 at 4°C. At 37°C binding was complete within 6 min. About 50% of bound ligand was internalized within 30 min at 37°C. The receptor demonstrated moderate lability at 37°C in culture. After 1 h at 37°C, PMN lost 80% of their 125l-rlFN-γ binding sites. This loss was reversed in part by the presence of interleukin-1 in the culture, but not tumor necrosis factor. These studies provide a framework for further investigation into the signalling process of rlFN-γ on PMN.
Specific Binding of Haptoglobin to Human Neutrophils and Its Functional Consequences
Authors: Oh S-K , Pavlotsky N , Tauber A I 
Published: January 2018

Abstract
Haptoglobin, an acute phase reactant protein, has been shown to modulate various facets of immune responses. In this paper we examined the effect of haptoglobin on human neutrophils at the molecular level. First, we found that native haptoglobin binds at two distinct sites on neutrophils. We then examined the effects of this binding at normal and pathophysiological concentrations of haptoglobin found in human serum. Of the various functional parameters assessed, neutrophil respiratory burst activity, as assessed by superoxide (O2-) production, was inhibited by native haptoglobin when the cells were stimulated with formylmethlonyl-leucylphenylalanine (FMLP), arachidonic acid (AA), and opsonized zymosan. The rise in intracellular calcium induced by FMLP stimulation was also inhibited by native haptoglobin. Since the generation of O2- was unaffected by native haptoglobin in phorbol myristate acetate (PMA)-stimulated neutrophils, the likely site of haptoglobin inhibition on neutrophil function is at a point of receptor-ligand interaction in the activation cascade. The role of haptoglobin as a modifier of the immune response has here been extended to altered neutrophil function stimulated by diverse agonists.
Priming Effect of Muramyl Peptides for Induction by Lipopolysaccharide of Tumor Necrosis Factor Production in Mice
Authors: Parant Monique , Parant Francine , Vinit Marie-Antoinette , Jupin Claude , Noso Yoshihiro , Chedid Louis 
Published: January 2018

Abstract
Lipopolysaccharide-induced necrosis of grafted tumors was potentiated by several hydrophilic and lipophilic muramyl dipeptide (MDP) derivatives administered a few hours prior to small amounts of lipopolysaccharide (LPS) in spite of low titers of induced circulating tumor necrosis factor (TNF). However, pretreatment with MDP derivatives did increase the level of TNF in the blood of mice challenged by a greater dose of LPS. The TNF amount in 2 h postendotoxin mouse serum reached a peak when the glycopeptide had been given 6 h before the challenge, being approximately 100-fold above that obtained in unprimed mice. The cytotoxic activity in mouse serum was inhibited by rabbit antibodies raised against recombinant mouse TNF. Although there exists a toxic synergism between BCG or MDP and endotoxin, the effect of certain MDP derivatives was not related to an increased susceptibility to the toxicity of LPS.
Hepatocyte Modulation of Kupffer Cell Prostaglandin E2 Production In Vitro
Authors: Billiar T R , Lysz T W , Curran R D , Bentz B G , Machiedo G W , Simmons R L 
Published: January 2018

Abstract
It is likely that dynamic interactions between hepatocytes and Kupffer cells contribute to the responses of these cell types both under normal conditions and during sepsis. In this study, we examined the influences of hepatocytes on the concentration of the inflammatory mediator PGE2 in Kupffer cell cultures. Evidence to suggest that cultured rat hepatocytes both metabolize PGE2 and produce a substance that promotes LPS-stimulated Kupffer cell PGE2 biosynthesis include the following: 1) PGE2 levels in Kupffer cell: hepatocyte coculture were lower than the levels in Kupffer cell cultures early after LPS stimulation; 2) 36 h after LPS, coculture PGE2 levels exceeded the levels in Kupffer cell cultures despite the demonstrated capacity for hepatocytes to metabolize PGE2; 3) a transferable, non-dialyzable, and heat-unstable factor in hepatocyte supernatant promoted PGE2 production when added to Kupffer cells with LPS or after LPS; 4) there was no increased PGE2 synthesis when the hepatocyte supernatant was added without LPS or if hepatocyte supernatant was preincubated with the Kupffer cells for 6 or 18 h before LPS administration; 5) there was an inability of the hepatocyte factor to promote PGE2 production in response to other macrophage-activating agents, including calcium ionophore A23187 or phorphol myristate acetate; and 6) there was no increased cell replication or protein synthesis in the Kupffer cell cultures following hepatocyte supernatant incubation. The increased Kupffer cell PGE2 production by the hepatocyte supernatant was not due to contamination of the hepatocyte supernatant by endotoxin or PGE2. These in vitro results raise the possibility that hepatocytes have the capacity to modulate local PGE2 levels by two distinct mechanisms. Hepatocytes can metabolize PGE2 as well as release factor(s) which promote LPS-induced PGE2 production by Kupffer cells.
Influenza A Virus Alters Structural and Biochemical Functions of the Neutrophil Cytoskeleton
Authors: Wheeler J Gary , Winkler Lisa S , Seeds Michael , Bass David , Abramson Jon S 
Published: January 2018

Abstract
Influenza A virus (IAV) has previously been shown to alter chemotactic, oxidative, and secretory functions of polymorphonuclear leukocytes (PMNL). Because of the role of cytoskeletal proteins in these processes, studies were carried out to determine if IAV altered the PMNL cytoskeleton. PMNL were incubated with buffer or IAV, stimulated with f-met-leu-phe (FMLP), fixed and stained with NBD-phallacidin (NBD-Ph) and studied by flow cytometry. Mean F-actin fluorescence was increased 18% in virus treated cells pre-FMLP stimulation and 13% 5 and 10 min post-FMLP (P &lt;.03); no significant difference in F-actin fluorescence was noted in virus treated PMNL 15–30 s post-FMLP compared to control cells. PMNL exposed to the same conditions were solubilized and actin content was determined following SDS-PAGE of triton insoluble precipitates. Increased actin was recovered from virus treated compared to buffer treated cells before and after FMLP stimulation in the 8,000g precipitates (P &lt;.001). Immunofluorescent microscopy studies of F-actin distribution were done in PMNL stained with NBD-Ph following FMLP stimulation for 10 min. These studies showed an increased lamellipod F-actin/uropod F-actin ratio in PMNL pre-incubated with IAV compared to controls (4.6 vs. 1.0; P &lt;.025). Phosphorylation of specific cytoskeletal proteins was examined after immunoprecipitation. IAV alone altered phosphorylation of both vlmentin and vinculin, and in stimulated PMNL virus led to decreased phosphorylation of vimentin and vinculin. These data show distributional and biochemical effects of IAV on PMNL cytoskeletal proteins, indicating additional targets for IAV interference in the PMNL signal-transduction-function process.
Tumor Necrosis Factor–Alpha Gene Expression in Human Whole Blood
Authors: Strieter Robert M , Remick Daniel G , Ham John M , Colletti Lisa M , Lynch Joseph P , Kunkel Steven L 
Published: January 2018

Abstract
Tumor necrosis factor-alpha (TNF) is recognized as a principal mediator of a variety of pathophysiologic and immunologic events. Lipopolysaccharide (LPS) challenge, either in vitro or in vivo, results in significant TNF production. In this study we present data demonstrating LPS-induced TNF mRNA expression and bioactivity using an in vitro tissue system of whole blood (WB). The kinetics of LPS-induced TNF production by WB was significantly accelerated as compared to isolated cultured peripheral blood monocytes (PBM). At post-LPS challenge, plasma from WB demonstrated a rapid rise in TNF bioactivity, peaking by 4 hr (1,021 units/ml/106 cells), plateauing between 4 and 8 hr, and then decreasing over the next 16 hr. In contrast, the highest measured TNF bioactivity from PBM did not occur until the 24-hr time-point (175 units/ml/106 cells). Whole blood buffy-coat TNF mRNA was assessed by Northern blot analysis, and demonstrated significant TNF mRNA accumulation at 1 hr and a peak 2 hr post-LPS challenge. By 8 hr TNF mRNA was undetectable. Concomitant administration of LPS with either prostaglandin E2 (10-6M) or Dexamethasone (10-6M) resulted in significant suppression of LPS-induced TNF production. This data supports WB as a useful in vitro medium for the molecular and cellular analyis of TNF. As specialized connective tissue, WB may provide an important environment to study the pharmacologic manipulation of TNF mRNA and bioactivity.
Quantitative Comparison of Myeloid Antigens on Five Lineages of Mature Peripheral Blood Cells
Authors: Terstappen L W M M , Hollander Z , Meiners H , Loken M R 
Published: January 2018

Abstract
Five-dimensional flow cytometry was used to identify the 5 lineages of peripheral blood leukocytes simultaneously in a single cell preparation. This technique was then used to compare quantitatively the distribution of cell surface antigens on each of these lineages of cells. Neutrophils, eosinophils, basophils, lymphocytes, and monocytes were uniquely identified by correlating their forward and orthogonal light scattering signals with the amount of cell surface-bound IgE. These three cellular characteristics were combined with two additional immunofluorescence labels to create a 5-dimensional space in which each leukocyte population occupied a unique position. The relative quantities of antigens on each cell type were determined for the monoclonal antibodies CD11b, CD13, CD14, CD15, CD16, CD33, CD38, CD45, CD45R, anti-HLA-DR, and anti-Leu-8 labeled with either fluorescein or phycoerythrin. The amount of antigen was described by the mean fluorescence intensity in comparison with the background fluorescence of each cell type. The distribution of the different cell surface antigens on the 5 major leukocyte populations as well as their interdonor variation were then correlated for 10 normal donors. Since none of the antigens studied was lineage specific, it was shown that the different lineages of blood cells could clearly be identified by quantitative comparison of the antigens. This study provides the basis for discrimination between mature cells and immature stages of differentiation of leukocytes and for distinction between normal and leukemic cells.