bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and Identification of Feline Peritoneal Macrophages for In Vitro Studies of Coronavirus-Macrophage Interactions
Authors: Stoddart Cheryl A , Scott Fredric W 
Published: January 2018

Abstract
Feline peritoneal cells were collected by lavage with Isotonic saline without the use of irritants or need for euthanasia of the cats. Macrophages were purified by centrifugation on Percoll followed by selective adherence. Although few macrophages could be obtained from an initial lavage, a second lavage performed on the same cat 9-11 days later yielded six times as many macrophages as the first lavage, providing sufficient numbers of cells for characterization and infection experiments. Macrophages from these subsequent lavages were not more functionally activated in phagocytosis assays than the resident macrophages from the initial lavage, and they were equally susceptible to infection with feline infectious peritonitis virus (FIPV). Infected cultures produced peak titers of 105.0 TCID50 per ml, and FIPV antigen was detected in a small subset (0.1-1.0%) of cells by indirect immunofluorescence. The FlPV-infected cells were identified as macrophages by their characteristic morphology and ability to phagocytize rhodamine-labeled latex beads. The successful isolation of large numbers of unactivated feline macrophages will permit in vitro studies of feline coronavirus-macrophage interactions that otherwise would not have been possible. Such studies will undoubtedly provide valuable insights Into the pathogenesis of feline infectious peritonitis, an invariably fatal disease of domestic and exotic cats.
Prostaglandin E2 and Thromboxane B2 Release From Human Monocytes Treated With Bacterial Lipopolysaccharide
Authors: Nichols Frank C , Garrison Scott W , Davis Harold W 
Published: January 2018

Abstract
We investigated the capacity of counterflow-isolated human monocytes to independently synthesize thromboxane B2 (TxB2) and prostaglandin E2 (PGE2) when stimulated with bacterial lipopolysaccharide (LPS). Independent metabolism was confirmed by establishing different specific activities (dpm/ng) of TxB2 and PGE2 released from LPS-treated cells. For metabolites released during the initial 2-hr treatment period, the specific activity of PGE2 was approximately threefold higher than that of TxB2 regardless of labeling with [3H] arachidonic acid (AA) or [14C]AA. Cells that were pulse-labeled for 2 hr with [3H]AA demonstrated a decreasing PGE2 specific activity over 24 hr, whereas the TxB2 specific activity remained unchanged. In contrast, cells continuously exposed to [14C]AA demonstrated an increasing TxB2 specific activity that approached the level of PGE2 by 24 hr. These results suggest the presence of at least 2 cyclooxygenase metabolic compartments in counterflow-isolated monocytes. Although freshly isolated monocytes have been reported to contain variable numbers of adherent platelets, additional experiments demonstrated that counterflow-isolated platelets are not capable of releasing elevated levels of TxB2 or PGE2 when treated with LPS. It is proposed from these findings that at least two subsets of monocytes exist in peripheral blood that can be distinguished on the basis of independent conversion of AA to TxB2 and PGE2.
Differentiation, Maturation, and Proliferation of Macrophages in the Mouse Yolk Sac: A Light-Microscopic, Enzyme-Cytochemical, Immunohistochemical, and Ultrastructural Study
Authors: Takahashi Kiyoshi , Yamamura Fumie , Naito Makoto 
Published: January 2018

Abstract
Primitive macrophages first appear in the blood islands of the mouse yolk sac on the ninth day of gestation. After the tenth day of fetal life, these cells differentiate into fetal macrophages and become mature, with the development of intracellular organelles. They appear in the mesenchymal layer and further immigrate into the extraembryonic coelom. The fetal macrophages do not show any cytochemical peroxidase or 5′-nucleotidase activity, and they possess a marked proliferative capacity. Promonocytes or monocytes that have an incomplete ultrastructure emerge in the blood islands of the yolk sac a day after the occurrence of the fetal macrophages. These events suggest that fetal macrophages differentiate from primitive macrophages before the development of promonocytes or monocytes in the mouse yolk sac; they actively proliferate and are colonized into the embryonic tissues. These results also indicate that the ontogeny of the monocyte/macrophage is different in the early embryo compared with its later developmental stages.
Lead-Induced Alterations of In Vitro Bone Marrow Cell Responses to Colony Stimulating Factor-1
Authors: Kowolenko Michael , Tracy Leigh , Lawrence David A 
Published: January 2018

Abstract
Bone marrow cell responsiveness to hemapoietic growth factors is an integral part of immune responsiveness. Since host resistance is often dependent on bone marrow cell responsiveness and Pb alters host resistance, the influence of Pb on bone marrow cell responsiveness to the hemapoietic growth factor CSF-1 was evaluated. Cell number, soft agar colony formation, cell cycle analysis, as well as 3H-thymidine incorporation were utilized to determine if CSF-1 driven bone marrow-derived macrophage (BMDM) proliferation in vitro is altered in the presence of PbCI2. Data obtained indicate that Pb potentiates the ability of CSF-1 to stimulate thymidine incorporation by BMDM; however, colony formation is inhibited reversibly, and the absolute number of cells in culture is adversely affected by Pb. Propagation of BMDM appears to be more sensitive to Pb (100 nM) than other immune parameters. The decrease in bone marrow cell responsiveness to CSF-1 in the presence of Pb observed in this system may contribute to the decrease in host resistance observed in Pb-exposed animals.
Selenium and the Immune Response: 1. Modulation of Alloreactive Human Lymphocyte Functions In Vitro
Authors: Petrie Howard T , Klassen Lynell W , Kay H David 
Published: January 2018

Abstract
A role for the dietary trace mineral element selenium in the reduction of cancer incidence has been documented in numerous epidemiological and experimental studies. The precise mechanism of this antitumor effect is not well understood, but published data suggest that both inhibition of tumor cell growth and enhancement of host immunity are likely to be involved. In this study we report that selenium at physiologic concentrations can inhibit human lymphocyte proliferation in response to irradiated tumor cells in mixed lymphocyte/tumor cell cultures (MLTC). In addition, we demonstrate that the various lymphocyte functional activities generated in these cultures exhibit different levels of sensitivity to the effects of selenium. The generation of suppressor-cell activity in MLTC was strongly inhibited by the presence of physiologic levels of selenium, while the development of cytotoxic T-lymphocyte activity in identical cultures was not affected by selenium. Production of interleukin-2 in these cultures showed an intermediate sensitivity to the effects of selenium. Thus, selenium appears to be capable of selectively regulating the generation of functional lymphocyte subsets in vitro. Such selective regulation could explain the published effects of selenium on immunity and would be consistent with a role for immunity in the observed reduction of cancer incidence associated with elevated selenium intake.
Selenium and the Immune Response: 2. Enhancement of Murine Cytotoxic T-Lymphocyte and Natural Killer Cell Cytotoxicity In Vivo
Authors: Petrie Howard T , Klassen Lynell W , Klassen Preston S , O’Dell James R , Kay H David 
Published: January 2018

Abstract
An inverse correlation between cancer incidence and dietary intake of the trace mineral element selenium has been well established in epidemiological and experimental studies. The mechanisms for this chemoprotective effect are unresolved. Much attention has been focused on the antiproliferative effects of selenium on various normal and neoplastic cell types. However, dietary selenium supplementation can also enhance the expression of various humoral and cellular immune responses. In examining the effects of dietary selenium on cell-mediated immunity in mice, we observed that selenium supplementation caused the enhanced expression of spontaneous natural killer (NK) cytotoxicity in spleen cells and of specific cytotoxic T-lymphocyte (CTL) cytotoxicity in peritoneal exudate cells (PEC). NK activity of spleen-cell suspensions from selenium-supplemented mice increased an average of 70% over that of the control group (basal diet). Cytotoxic activity of PEC from mice injected with tumors intraperitoneally peaked earlier in selenium-supplemented animals, and the appearance of cells staining positively for Thy 1.2 surface antigen in selenium-supplemented animals also preceded the values observed in control animals. We propose here that enhancement of in vivo cytotoxic mechanisms, is likely to act synergistically with tumor growth inhibition in the reduction of tumor incidence associated with selenium intake.
Influence of a Cytomegalovirus Infection on Functions and Arachidonic Acid Metabolism of Rat Peritoneal Macrophages
Authors: Engels Wim , Grauls Gert , Lemmens Paul J , Mullers Wil J , Bruggeman Cathrien A 
Published: January 2018

Abstract
An intraperitoneal (rat) cytomegalovirus (RCMV) infection in the rat caused an influx of mononuclear cells, which have been altered in functions and arachidonic acid (AA) metabolism. Phagocytosis has been increased considerably 3 days postinfection (p.l.), whereas the release of prostacyclin, thromboxane A2, 12-hydroxyheptadecatrienoic acid (HHT), 5-hydroxyeicosatetraenoic acid (5-HETE), and leukotriene B4 (LTB4) was inhibited for more than 80%. The release of superoxide anions and the chemiluminescence response (CL) upon opsonized zymosan stimulation did not differ from those observed in resident peritoneal macrophages. Additionally, the levels of cyclic nucleotides (cAMP and cGMP) were low in both resident and influx macrophages (day 3 p.i.). In contrast, peritoneal macrophages harvested on day 10 p.i. still showed a high level of phagocytosis. However, the intracellular level of cyclic AMP had decreased fivefold, whereas CL response and superoxide anion release were inhibited significantly. Moreover, the production of prostacyclin, LTB4, and 5-HETE was still suppressed in contrast to thromboxane synthesis, which has selectively been restored in these macrophages. A direct regulatory role of AA metabolites in changes in macrophage functions that were due to a RCMV infection could not be demonstrated.
Increased Production of Cytotoxic Macrophage Progenitors by Lactobacillus casei in Mice
Authors: Nanno Masanobu , Shimizu-Takeda Takako , Mike Akito , Ohwaki Makoto , Togashi Yuji , Suzuki Ryuji , Kumagai Katsuo , Mutai Masahiko 
Published: January 2018

Abstract
Heat-killed Lactobacillus casei YIT9018 (LC9018). when administered intravenously to normal mice, induced increase in Mac-1+ cells and Mac-2+ cells but not in Mac-3+ cells in spleen. The number of both populations changed in the same time course and was maximal 14 d after the administration. To know the effect of LC9018 on hematopoietic progenitor level, we examined the number of macrophage colony-forming cells (M-CFC), granulocyte-macrophage CFC (GM-CFC), and colony-forming units in spleen (CFU-S) in bone marrow 3 d after the administration. LC9018 stimulated the proliferation of M-CFC but not that of GM-CFC and CFU-S. LC9018-induced M-CFC were similar to normal M-CFC in dependence on macrophage colony-stimulating factor (M-CSF) and buoyant density. M-CFC-derived macrophages cultured in the presence of M-CSF expressed Mac-1 and Mac-2 but not Mac-3. They showed cytotoxic activity against syngenic tumor cells, Meth A, via direct contact, when assayed by using an in vitro colony inhibition assay or an in vivo Winn test. These results indicate that LC9018 stimulates the proliferation of cytotoxic macrophage progenitors in bone marrow and induces their differentiation in spleen. These effects may be one of the ways in which LC9018 suppresses tumor growth.
Role for Arachidonic Acid Metabolism and Protein Synthesis in Recombinant Bovine lnterferon-γ–lnduced Activation of Bovine Neutrophils
Authors: Steinbeck Maria J , Webb Deborah S A , Roth James A 
Published: January 2018

Abstract
Bovine neutrophils were preincubated with recombinant bovine interferon-γ (rbolFN-γ), and the molecular events leading to enhanced antibody-dependent (ADCC) and antibody-independent (AINC) neutrophil-mediated cytotoxicity and reduced random migration under agarose were investigated. Addition of α-amanitin, puromycin, or cycloheximide (RNA and protein synthesis inhibitors) during preincubation and assaying prevented the rbolFN-γ–induced AINC enhancement and migration inhibition, but did not influence the enhancement of ADCC. Treatment of neutrophils with rbolFN-γ consistently increased the synthesis of a 60 and a 94–95 kilodalton protein and of leukotriene B4 and 5-HETE. Neutrophils isolated from dexamethasone-treated cattle showed similar protein synthetic activity after rbolFN-γ treatment, but these cells failed to show enhanced AINC. Neutrophils from dexamethasone-treated cattle have been shown to have depressed arachidonic acid metabolism. Addition of lipoxygenase inhibitors (NDGA and BW755c) to neutrophils from nondexamethasone-treated cattle following preincubation with rbolFN-γ (i.e., after protein synthesis had occurred) eliminated the enhancement of AINC. Thus it was concluded that the metabolic events required for neutrophil activation by rbolFN-γ are different for the three functions measured. The enhanced AINC response required both arachidonic acid metabolism and protein synthesis, inhibition of random migration required only protein synthesis, and enhancement of ADCC required neither.
Initial Characterization of a Cytokine Which Induces Differentiation and Cytolytic Activity in HL-60 Promyelocytic Leukemia Cells: Evidence That the Cytokine Is Distinct From Other Known Differentiation-Active Cytokines
Authors: Leftwich Julie A , Hall Robert E 
Published: January 2018

Abstract
In this paper we report that, like dimethyl sulfoxide (DMSO), retinoic acid (RA), and conditioned medium (CM) from lectin-stimulated mononuclear leukocytes, CM from a human null cell leukemia line (Reh) induces HL-60 promyelocytic leukemia cells to respond in an enhanced manner to phorbol diester (PDE). Furthermore, Reh-CM induces PDE-resistant HL-60-1E3 cells to respond to PDE and lyse target cells. Additionally, both HL-60 and HL-60-1E3 cells exposed to Reh-CM for 3 days produce superoxide anion and express cell surface antigens present on mature mononuclear phagocytes. No colony-stimulating factor (CSF) or interferon (IFN) activity was detected in Reh-CM, and differentiation activity (DA) was not removed from Reh-CM by insolubilized anti-IFNγ. While Reh-CM is antiproliferative against a panel of cell lines, its spectrum of activity is different than tumor necrosis factor (TNF)α, and neither TNFα nor TNFβ inhibit proliferation of HL-60-1E3 or induce these cells to respond to PDE. The differentiation factor (DF) material has been partially purified by ammonium sulfate precipitation and is non-dialyzable; unstable to heat, acid, or alkali treatment; and the activity is not blocked by anti-IL-6 or anti-IFNα. The data presented in this paper suggest the presence of a differentiation-inducing factor which is distinct from CSF, IFNα or -γ, TNFα or -β, or IL-6, which may play a role in the differentiation of malignant (leukemic) and normal cells of the myelomonocytic lineage.
Difference in Changes of Membrane Fluidity of Polymorphonuclear Leukocytes Stimulated With Phorbol Myristate Acetate and Formyl-Methionyl-Leucyl-Phenylalanine: Role of Excited Oxygen Species
Authors: Masuda Midori , Komiyama Yutaka , Murakami Takashi , Murata Kenjiro , Hasui Masafumi , Hirabayashi Yoichi , Kobayashi Yohnosuke 
Published: January 2018

Abstract
Polymorphonuclear leukocytes (PMN) were stimulated with phorbol myristate acetate (PMA) and N-formyl-methionyl-leucyl phenylalanine (FMLP) to clarify the role of excited oxygen species in inducing changes of membrane fluidity. Membrane fluidity was assessed by the excimer-forming lipid technique using pyrenedecanoic acid and flow cytometry. Membrane fluidity of PMN decreased following stimulation with PMA, and the extent of decrease was both time- and dose-dependent. FMLP at 10-5 M induced a decrease, while FMLP at 10-7 M induced a rapid increase. On stimulation with 10-7 M FMLP as well as in a resting condition, the change of membrane fluidity of PMN from patients with chronic granulomatous disease (CGD) was similar to that of normal PMN. However, on stimulation with PMA or 10-5 M FMLP, CGD PMN did not show a significant decrease. In addition, normal PMN incubated with catalase inhibited the decrease. These findings suggest that the generation of excited oxygen species, particularly of H2O2, is important in inducing a decrease of PMN membrane fluidity.
Interleukin-4 Downregulates Interleukin-6 Production in Human Peripheral Blood Mononuclear Cells
Authors: Lee Jeffrey D , Swisher Stephen G , Minehart Elaine H , McBride William H , Economou James S 
Published: January 2018

Abstract
We report that recombinant human interleukin-4 (IL-4) downregulates interleukin-6 (IL-6) production by human peripheral blood mononuclear cells (PBMC). PBMC were preincubated for up to 24 hr in the presence of IL-4 (100 U/ml) and then activated with li-popolysaccharide B Escherichia coli 026:B6 (LPS, 10 μg/ml), recombinant human tumor necrosis factor-α (TNF-α, 200 U/ml), or Concanavalin A (Con A, 10 fig/ml). Although all these signals induced IL-6 production, IL-4-treated cells produced significantly reduced levels of IL-6 protein. This effect was dose and time dependent. We conclude that IL-4 is a potent downregulatory modulator of IL-6 expression in human PBMC.
Taurine and Hypotaurine Content of Human Leukocytes
Authors: Learn Douglas B , Fried Victor A , Thomas Edwin L 
Published: January 2018

Abstract
Taurine (T) was reported to be at high concentrations in human leukocytes. It was proposed that T is a scavenger for chlorinated oxidants produced by the myeloperoxidase system of monocytes and neutrophils. Hypotaurine (HT) would be a more effective scavenger, and HT could also detoxify products of bromide or iodide oxidation produced by the eosinophil peroxidase system. Methods previously used to measure T in leukocytes might oxidize HT to T or fail to separate T and HT. Therefore, we examined T and HT content, uptake, and biosynthesis in isolated blood cells and cultured tumor cells derived from hematopoietic/lymphoid cells. Platelets and all leukocytes including monocytes, lymphocytes, neutrophils, and eosinophils had high T levels (10–20 mM), and all except eosinophils had substantial HT levels (0.3–1 mM). Intracellular levels were 500-times higher than in plasma. Erythrocytes were the only blood cells with low levels of both T and HT. Tumor cells from lymphoid (CCRF-CEM) and myeloid (HL-60, K-562, RWLeu4, HEL) lineages took up and concentrated T and HT from the bovine calf serum in the culture medium, and intracellular levels were similar to those in leukocytes. When cells were cultured in HT-supplemented media, HT almost completely replaced T, and HT was not converted to T. Levels of T were not raised by culturing cells with possible precursors, but HT levels were raised when cysteine sulfinic acid was present. Washed tumor cells took up T and HT by way of a β-amino acid transport system, but uptake by leukocytes was very low. Therefore, leukocytes may acquire T and HT by active uptake rather than biosynthesis, and uptake may be completed during differentiation in the bone marrow. Though HT is low relative to T, HT levels may be sufficient to protect leukocytes from toxic oxidants.
Interferon-γ Induced Resistance to Legionella pneumophila in Susceptible A/J Mouse Macrophages
Authors: Klein Thomas W , Yamamoto Yoshimasa , Brown H Keith , Friedman Herman 
Published: January 2018

Abstract
Legionella pneumophila (Lp) grow in cultures of human, guinea pig, and mouse macrophages from A/J strain mice. Because exudate macrophages from this strain of mice have been reported deficient in responsiveness to lymphokines, we thought it of interest to document the extent of responsiveness to interferon-γ in the context of growth restriction of Lp. Peritoneal exudate macrophages were obtained from A/J mice and cultured in either the presence or absence of recombinant lnterferon-γ. These cultures were then infected with Lp and the extent of bacterial growth estimated 48 hr later by means of a colony-forming unit (CFU) assay and electron microscopy, lnterferon-γ treatment significantly restricted the number of CFUs in the culture at concentrations as low as 20 U/ml, but did not affect the uptake of bacteria by macrophages. Furthermore, treatment with interferon induced morphological changes consistent with activated macrophages. The involvement of oxygen-dependent mechanisms in phagocyte killing and growth restriction was examined by the use of inhibitors such as superoxide dismutase (SOD) and catalase. Neither one of these inhibitors of toxic oxygen metabolites affected the interferon-γ-induced suppression of Lp growth. These results suggest that although thioglycolate-induced exudate macrophages from A/J mice support the growth of Lp, these cells readily respond to the activating influence of lnterferon-γ. Furthermore, lymphokine treatment does not inhibit Lp uptake by macrophages and apparently restricts the growth of bacteria by mechanisms independent of the activity of toxic oxygen metabolites.
Tumor-Derived Products Induce Il-1 a, Il-1 b, Tnf a, and Il-6 Gene Expression in Murine Macrophages: Distinctions Between Tumor- and Bacterial Endotoxin-Induced Gene Expression
Authors: Evans Robert , Kamdar Sonya J , Duffy Theodore M 
Published: January 2018

Abstract
The ability of progressing tumors to regulate host physiology is an important consideration in our understanding of tumor-host relationships. Previous data indicated that several lines of murine sarcoma cells produced one or more activities that were able to regulate both Il-1 a and Il-1 b gene transcription in macrophages (Mø). We now describe an indepth analysis using Northern analysis and bioassays and show that two of these tumors produce one or more activities that when incubated with peritoneal Mø result in the transcription of the Il-a, Il-1 b, Tnf a, and Il-6 genes. Concordant with the Northern analyses was the finding that interleukin-1 (IL-1) and tumor necrosis factor (TNF) biological activities were detected in lysates of induced Mø, fixed Mø, and supernates of Mø cultures. Induction of gene expression was shown to be distinct from that induced by bacterial endotoxin or lipopolysaccharide by a number of criteria. The data suggest that tumor cell products may play an important role in regulating several host physiological processes, particularly those involving Il-1 a, Il-1 b, Tnf a, and Il-6 gene expression.