bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction of Serum Interleukin-1-Like Activity After Treatment With Dexamethasone
Authors: Staruch Mary Jo , Wood David D 
Published: January 2018

Abstract
The ability of steroids to modulate the appearance of interleukin-1(IL-1) in vivo was evaluated in a model of endotoxin shock. High levels of IL-1 were found in serum from A/J mice which were sensitized with P. acnes and challenged with bacterial lipopolysaccharide (LPS). The factor appeared in the serum 2–4 hours after LPS challenge and was dependent on the period of P. acnes sensitization and the dose of LPS. Treating the mice with dexamethasone prior to LPS challenge resulted in significantly lower thymocyte proliferative activity in the serum. Three experiments demonstrated that this reduced activity reflects a decrease in IL-1. 1) The reduced activity was not due to the presence of proliferation inhibitors since mixing the serum from dexamethasone-treated mice with purified IL-1 or adding the equivalent amount of steroid directly to thymocyte cultures did not reduce the degree of proliferation. 2) When the serum was fractionated by gel filtration, the proliferative activity for both control and steroid treated sera eluted at 10–16 kilodaltons; however, the activity was nearly 50% less in the sample from steroid-treated mice. 3) In addition to thymocyte proliferative activity, IL-1 induces an increase in the serum titer of the acute phase protein known as serum amyloid A. Both serum- and gel- purified samples were able to induce the SAA, but again the samples from steroid-treated mice were much less active. We conclude that the factor produced in vivo has the properties of IL-1 and that the serum titre of the factor is reduced by dexamethasone treatment.
Macrophage Activation by Cross-Linked Dextran
Authors: Blanckmeister Carolyn A , Sussdorf Dieter H 
Published: January 2018

Abstract
Cross-linked dextran (Sephadex) has been reported as an effective inducer of peritoneal exudates resulting in a large yield of macrophages after injection into mice, and macrophages obtained in this manner have been used for a variety of studies. We examined the possibility that cross-linked dextran not only induces peritoneal exudate but functions also as a macrophage activator. Following confirmation of a markedly increased yield of macrophages in Balb/ c mice injected with preswollen Sephadex G-25 beads, glass adherence and migration in agarose of these macrophages were compared with the activities of cells isolated following the injection of saline, thioglycollate, or complete Freund's adjuvant (CFA). Dextran administration resulted in a significant increase in these activities in relation to saline and thioglycollate injections, and resembled CFA in the magnitude of its effect. Dextran-induced macrophages were then examined for activation as defined by nonspecific antitumor activity. Cells of a transplantable fibrosarcoma line and a urethane-induced primary lung adenoma served as targets. As compared with macrophages isolated from saline-injected mice, cells induced by Sephadex showed an approximately fivefold and twofold increase in activity against adenoma and fibrosarcoma targets, respectively. To examine the ability of Sephadex to induce macrophage antitumor activity in vitro, peritoneal macrophages were cultured in the presence of the dextran for 24 hours and tested against adenoma targets. The tumoricidal/static activity of such macrophages was significantly increased relative to controls and was nearly identical to the activity of macrophages induced by Sephadex in vivo. It is clear that cross- linked dextran in the form of Sephadex G-25 can function both as an inducer of peritoneal exudate and as an effective macrophage activator with regard to the activation criteria studied.
Uptake of Extracellular Calcium by Neonatal Neutrophils
Authors: Strauss Ronald G , Snyder Esther L 
Published: January 2018

Abstract
Neutrophils from human neonates exhibit abnormalities of plasma membrane and cytoskeletal dependent functions such as chemotaxis, deformability, and lectin capping. The uptake of extracellular calcium by neutrophils is a key early event in neutrophil activation and in the optimal performance of these functions. We found that neonatal and control neutrophils acquire extracellular radioactive calcium comparably under most experimental conditions. No differences (P &gt; 0.05) were seen between neonatal and control neutrophils following stimulation with soluble sodium fluoride, N-formyl-methionyl-L-leucyl-L- phenylalanine, dimethylsulfoxide, and opsonized zymosan particles. However, the uptake of calcium by resting (unstimulated) neutrophils was significantly less (P &lt; 0.0001) by neonatal cells. The kinetics of calcium uptake by neonatal and control neutrophils were similar both at rest and following stimulation for 15 min with sodium fluoride. Although additional studies will be necessary to completely define the ionic events involved in the chemotaxis of neonatal neutrophils, it seems unlikely that the abnormal mobility of these cells is due simply to an inability of neonatal neutrophils to acquire extracellular calcium in response to cellular stimulation.
Analysis of Human Monocyte Chemoattractant Binding by Flow Cytometry
Authors: Leonard Edward J , Noer Kathleen , Skeel Alison 
Published: January 2018

Abstract
The chemotactic peptide fMet-Leu-Phe-Lys is a potent chemoattractant for human blood monocytes. However, only one-third of the monocytes respond. To determine whether or not lack of response reflected absence of attractant receptors, we equilibrated peripheral blood mononuclear cells with fMet-Leu-Phe-Lys-FITC and analyzed binding by flow cytometry. The fluoresceinated peptide bound rapidly at 0°, and the amount bound approached saturation with increasing concentration. The percentage of blood monocytes that bound the peptide was 60 ± 8 (SEM for seven experiments). In contrast, only 36 ± 3% (SEM for 16 experiments) of monocytes responded to the attractant by directed migration. It follows that, among the 64 nonmigrating monocytes per 100 total monocytes, approximately 40, or two-thirds of them, fail to bind attractant; the remaining one-third bind attractant but do not respond with directed movement.
The Chemotactic Response of Granulocytes to the Low Molecular Weight Chemoattractants f-MLP, C5f, and LTB4 Is Dependent on Chemokinetic Factors
Authors: Håkansson Lena , Venge Per 
Published: January 2018

Abstract
The dependence of the low molecular weight chemoattractants (LMCs) formyl-methionyl-leucylphenylalanin (f-MLP), C5f, and leukotriene B4 (LTB4) on albumin to express their chemotactic activity towards granulocytes (PMNs) was investigated in order to study the required qualities of albumin and if albumin could be replaced by any other proteins. The results demonstrated that the supporting effect of isolated albumin was dependent on the method of purification. Only isolated albumin exposed to ethanol precipitation during the purification procedure supported the chemotactic effect of LMCs. The albumin preparation that supported the effect of LMCs also mediated a chemokinetic effect on PMN migration. Albumin isolated by methods other than ethanol precipitation neither exerted a chemokinetic effect nor supported the chemotactic effect of LMCs. Heated, normal serum and isolated α1-antitrypsin supported the chemotactic activity of LMCs and also mediated a chemokinetic effect on PMN migration.
The present investigation suggests an important role for the chemokinetic factors, since it is indicated that their presence is necessary for the chemotactic response of PMNs to the low molecular weight chemoattractants C5f, LTB4, and f-MLP.
The Interaction of Murine Cytomegalovirus With Murine Neutrophils: Effect on Migratory and Phagocytic Activities
Authors: Bale James F , O'Neil Marsha E , Greiner Timothy 
Published: January 2018

Abstract
To investigate the interaction of cytomegalovirus (CMV) with neutrophils, we studied the effects of in vitro incubation of murine neutrophils with murine CMV (MCMV). Neutrophils incubated with MCMV for 4 h had depressed chemotactic activity, mean chemotactic index of 1.34 ± 1.43 for MCMV-treated neutrophils vs 3.22 ± 2.11 for controls. Engulfment of latex spheres by MCMV-treated neutrophils was also reduced. These differences were not attributable to loss of cell viability. UV-inactivation of MCMV pools abolished the inhibitory effects of MCMV, indicating that these effects were related to infectivity of the virus. Electron microscopic studies at 4 h demonstrated virus particles within the phagosomes of occasional neutrophils. These studies demonstrate that neutrophil functions can be altered by an in vitro interaction with infectious CMV and suggest that a direct effect of CMV on neutrophils could account for the abnormal neutrophil functions observed during animal CMV infections.
Red Blood Cell Homeostasis: Recognition of Distinct Types of Damaged Homologous Red Blood Cells by a Mouse Macrophage Cell Line
Authors: Singer Judith A , Morrison Martin , Walker William S 
Published: January 2018

Abstract
The mouse macrophage (MΦ) cell line IC-21 preferentially ingests a subpopulation of homologous red blood cells (MRBC) from normal mice. This subpopulation presumably bears the so-called transfusion lesion, a consequence of damage acquired during the drawing and processing of blood. To determine if all damaged MRBC were recognized by a common receptor site on IC-21 MΦ, we prepared suspensions of MRBC damaged in vitro by treatment with tannic acid and compared the phagocytic uptake of these cells with those bearing the transfusion lesion. Trypsin treatment of IC-21 MΦ rendered them unable to recognize MRBC bearing the transfusion lesion; but it had no effect on the uptake of tannic acid-damaged MRBC, showing that IC-21 MΦ have separate recognition sites for these two populations of damaged MRBC.
Dynorphin and Related Opioid Peptides Enhance Tumoricidal Activity Mediated by Murine Peritoneal Macrophages
Authors: Foster James S , Moore Robert N 
Published: January 2018

Abstract
The influence of dynorphin A (DYN) and related opioid peptides on the tumoricidal function of activated murine peritoneal exudate macrophages (PEM) was investigated. Addition of DYN to macrophage cultures previously activated with mixed α + β-inter-feron (IFN-α/β) and bacterial lipopolysaccharide (LPS) significantly enhanced their ability to lyse P815 murine mastocytoma cells in a 16 hr chromium-release assay. The effects of DYN were dependent on prior macrophage activation. Peptide subfragments of DYN were effective in a manner similar to that of the 17-amino-acid parent molecule, indicating that peptide interaction with either κ or δ-opioid receptors on the effector cell is effective in potentiating lytic function. The involvement of opiate receptors was confirmed by inhibition of the effects of DYN and leucine enkephalin by the opioid receptor antagonist naloxone. Finally, in addition to IFN-α/β-primed macrophages, DYN also augmented tumoricidal function in PEM primed for cytotoxicity by either γ-interferon (IFN-γ) or the calcium ionophore A23187, Indicating that DYN potentiates function in activated macrophages independent of the specific mode of activation.
Regulation of Large Granular Lymphocytes and Human T Cell Growth and Function by Recombinant Interleukin 2. II. Acquisition of Potent Cytotoxic Capabilities
Authors: Yamada Sachihiro , Ortaldo John R 
Published: January 2018

Abstract
Human large granular lymphocytes (LGL) and T cells were separated from peripheral blood on discontinuous density gradients of Percoll. On a per cell basis, cultured LGL demonstrated higher levels of cytotoxicity against K562 cells than fresh LGL. Cultured T cells acquired cytotoxicity against K562 cells, although they were less cytotoxic than fresh or cultured LGL. During culture, these LGL retained the 3G8, NKH1, OKM1, and OKT10 antigens. Cultured T cells retained the T101 antigen and acquired the OKM1 and OKT10 antigens, but remained negative for the 3G8 or NKH1 antigens. A series of pharmacologic agents known to inhibit cytotoxicity of fresh LGL were also tested for their effects on cultured LGL and T cells. Ethylenediaminetetraacetic acid, known to inhibit the binding of effectors to target cells, inhibited the cytotoxicity of cultured LGL and T cells to the same degree that it inhibited the cytotoxicity of fresh LGL. In contrast, agents which primarily effect post-binding events in cytotoxicity (trypsin, D-mannose 6-P, dexamethasone, prostaglandin E2, anti-LGL granule antibody, and 9.1C3 monoclonal antibody) inhibited the cytotoxicity of cultured LGL and T cells to a much lesser extent than fresh LGL. In addition, on the basis of Michaelis-Menten’s kinetic analysis, cultured LGL and T cells developed a higher binding affinity to K562 cells than fresh LGL.
Pertussis Toxin Blocks the Inhibitory Effects of Calcitonin on Cyclic AMP Accumulation in Stimulated Cultured Human Monocytes
Authors: Stock John L , Coderre James A 
Published: January 2018

Abstract
Surface stimulation of fresh or cultured human mononuclear cells by latex particles causes an increase in the accumulation of cyclic AMP that is inhibited by preincubation with calcitonin (CT). Preincubation of cultured monocytes with 500 ng/ml pertussis toxin totally blocks the inhibitory effects of CT at low concentrations of this hormone. The effects of pertussis toxin are dose-related and eliminated by boiling the toxin. Similar preincubations with cholera toxin have no significant effects on subsequent inhibition of surface-stimulated cyclic AMP by CT. Membranes prepared from cultured human monocytes contain a 41,000-dalton protein that is ADP-ribosylated by pertussis toxin and may be the inhibitory guanine nucleotide regulatory protein (N) mediating this inhibition.
Concentrations of Immunoreactive Human Tumor Necrosis Factor Alpha Produced by Human Mononuclear Cells In Vitro
Authors: van der Meer Jos W M , Endres Stefan , Lonnemann Gerhard , Cannon Joseph G , Ikejima Takashi , Okusawa Seijiro , Gelfand Jeffrey A , Dinarello Charles A 
Published: January 2018

Abstract
The concentrations of tumor necrosis factor (TNF) produced by human peripheral blood mononuclear cells (MNC) were measured using a radioimmunoassay (RIA) for human TNF. This was developed using a rabbit antiserum against human recombinant TNF (Hu rTNF), and Hu rTNF labeled with Na1251 by a modification of the chloramine T method. This RIA does not detect human lymphotoxin, interieukin-1 alpha or beta, interleukin 2, interleukin 6, interferon alpha or gamma, granulocyte-macrophage-colony stimulating factor, and C5a des arg. A good correlation (r = 0.89) was found between the RIA and the cytolytic bioassay for TNF. The sensitivity of the RIA is between 3 and 78 pg/ml (median 11 pg/ml).
The mean concentration of TNF in 24-h culture supernatants of human MNC exposed to different concentrations of lipopolysaccharide (LPS) was found to increase in dose-dependent fashion and then level off between 50 and 100 ng/ml. The concentrations of IL-1 beta and alpha detected by specific RIAs in these supernatants were between 0.2 and 19 ng/ml and 0.04 and 1 ng/ml, respectively. The amount ot TNF produced by human MNC in vitro was determined in a cohort of 50 normal volunteers. Without exogenous stimuli, TNF concentrations were almost always below the detection limit; with 0.5 ng/ml LPS, the median concentration of TNF was 2 ng/ml, and with PHA the median was 3.8 ng/ml. In cultures performed in the presence of indomethacin significantly (p&lt; 0.005) more TNF was produced.
Using this RIA, we could detect TNF in the circulation of mice injected with Hu rTNF. When plasma samples of patients with febrile illnesses were added directly to the RIA, TNF was not detectable, with the exception of patients with malaria.
These studies demonstrate the range and sensitivity of LPS-induced and mitogen-induced production of immunoreactive TNF by human MNC in vitro without interference of similar cytokines in bioassays.
Measurement of Intracellular Fluorescence of Human Monocytes Relative to Oxidative Metabolism
Authors: Robinson J Paul , Bruner Leon H , Bassoe Carl-F , Hudson Jerry L , Ward Peter A , Phan Sem H 
Published: January 2018

Abstract
Human monocytes (MN) produce O2- and H2O2 when stimulated by agonists. Dichlorofluorescin diacetate (DCFH-DA) has been used as a substrate for measuring intracellular oxidant production in neutrophils. DCFH-DA is hydrolyzed by esterases to dichlorofluorescin (DCFH), which is trapped within the cell. This nonfluorescent molecule is then oxidized to fluorescent dichlorofluorescin (DCF) by action of cellular oxidants. DCFH-DA can not be appreciably oxidized to a fluorescent state without prior hydrolysis. We have examined the utility of DCFH-DA for the assessment of monocyte oxidative responses. The levels of intracellular fluorescence measured by flow cytometry were considerably less than expected from reported levels of O2--production or chemiluminescence assays. Compared with neutrophils, monocytes produced minimal increases in DCF fluorescence after stimulation with phorbol myristate acetate as measured by flow cytometry, but both cell types showed increases in fluorescence when bulk cell suspensions were measured by spectrofluorometry. To determine the intracellular location of the DCFH, bulk fluorescence measurements were made on both whole and sonicated cell preparations. When intact mononuclear cells were preloaded with DCFH-DA, then sonicated and oxidized with added excess H2O2, the increase in fluorescence was only 30% of the fluorescence of mononuclear cell sonicates to which DCFH-DA was added and oxidized in a similar manner. These results suggest that a portion of the DCFH-DA incorporated by intact cells, is not susceptible to oxidation by the added H2O2. Addition of NaOH to induce hydrolysis of any residual DCFH-DA in the sonicates of DCFH-DA-loaded intact mononuclear cells resulted in a further increase in fluorescence upon addition of H2O2, suggesting that a significant portion of the DCFH-DA was not hydrolyzed despite ample uptake of this dye by these cells. In contrast, no further increase in fluorescence was observed in sonicates of DCFH-DA-loaded intact neutrophils, suggesting complete hydrolysis of all incorporated DCFH-DA to DCFH. When monocytes were allowed to phagocytose DCFH-DA-loaded Staphylococcus aureus, intracellular fluorescence was measurable by flow cytometry, indicating intracellular oxidation of the fluorochromes. We therefore propose that in monocytes the mechanism of intracellular processing of these fluorochromes differs from that in neutrophils owing to differences in intracellular localization of fluorochromes, site of oxidant production, and/or accessibility of the DCFH-DA to esterolysis.
Incorporation of LPS in Liposomes Diminishes Its Ability to Induce Tumoricidal Activity and Tumor Necrosis Factor Secretion in Murine Macrophages
Authors: Dijkstra Jan , Larrick James W , Ryan John L , Szoka Francis C 
Published: January 2018

Abstract
We investigated the effect of lipopolysaccharide (LPS) incorporated into phospholipid vesicles (liposomes) on the induction of macrophage-mediated tumor cytotoxicity and tumor necrosis factor (TNF) secretion. The incorporation of Salmonella minnesota rough (Re)-LPS into multilamellar or small unilamellar vesicles (liposomes) resulted in an 100-to 1,000-fold reduction in its potency to activate both the macrophage cell line RAW 264.7 and murine thioglycolate elicited peritoneal macrophages to become cytotoxic for L929 and P815 tumor cells. Liposomal LPS was also a 100- to 1,000-fold less potent inducer of TNF secretion from RAW 264.7 cells. Cytokines secreted by the activated macrophages contributed to the cytotoxic effect on the L929 cells but not the P815 cell line. Human recombinant TNF was not cytotoxic for either cell line but was cytostatic for the L929 cell line. Morphological examination of the cells after uptake of fluorescent, free, and liposomal LPS revealed that both forms were internalized by the endocytic pathway. This, together with the considerably reduced potency of liposomal LPS to induce tumor cytotoxicity and TNF secretion, suggests that the interaction of the hydrophobic part of the lipid A moiety of LPS with the macrophage plasma membrane is needed to optimally activate these cells. Incorporation of LPS into liposomes effectively abrogates this interaction.
Flow Cytometric Analysis of I-J Expression on Murine Bone Marrow-Derived Macrophages
Authors: Malley A , Stewart C C , Stewart S J , Waldbeser L , Bradley L M , Shiigi S M 
Published: January 2018

Abstract
Attempts to analyze bone marrow-derived macrophages (BMDM) by flow cytometry have been prohibited because of their high autofluorescence. Using an autofluorescence reduction method of Steinkamp and Stewart to reduce the autofluorescence of BMDM, we were able to examine several macrophage populations for their expression of I-A, I-J, and Mac-1 cell surface determinants. Bone marrow cells examined immediately after removal from the femur contain 50–60% Mac 1-positive cells (mainly granulocytes). During the next few days granulocytes and nonmacrophage precursor cells die, and the number of Mac 1-positive cells decrease. Once the bone marrow cells have been maintained in L cell conditioned medium (LCM) for 2 to 3 days, the number of cells expressing Mac 1 increases rapidly from 20% to 98% during the next 3 to 4 days. Bone marrow cells grown in LCM do not express I-J until these cells have been in culture 3 to 4 days, and the number of cells expressing I-J (up to 90% positive) parallels the increase in macrophages. Bone marrow cells maintained in LCM did not express detectable I-A during the 14 days these cells were examined. Two other macrophage populations often used in a variety of immunological studies were analyzed by flow cytometry. We found that the majority (up to 80%) of peritoneal cells expressed I-A, and only 20% of peritoneal cells had I-J cell surface determinants. On the other hand, peritoneal exudate cells collected 4 days after thioglycolate medium treatment were predominantly I-J positive (up to 70%), and only about 30% of these cells expressed I-A cell surface antigens.
The binding of anti-I-J IgM antibody to BMDM was not to Fc receptors because pretreating these cells with up to 25 μg of an IgG2a myeloma protein did not block anti-I-J antibody binding. The addition of 25-200 μg of monoclonal anti-Fc receptor antibody was also ineffective in blocking the binding of a monoclonal anti-I-Jk antibody to BMDM. Pretreatment of BMDM with the IgM fraction of several control IgM antibody preparations did not block the specific binding of fluoresceinated anti-I-J IgM antibody.
BMDM provide a pure population of macrophages that express a significant level of cell surface I-J antigens. Bone marrow cells grown in LCM are essentially devoid of other contaminating cells, and the increase in the number of I-J-positive cells parallels the increase in macrophages in these cultures. Thus, the further study of BMDM may permit resolution of questions raised by molecular biologists and immunologists regarding the nature of the I-J protein, the location of I-J genes, and the role of I-J in regulating immune responses.