bluuebunny/crossref_metadata_2025 huggingface dataset:
Unaggregated serum IgA binds to neutrophil FcαR at physiological concentrations and is endocytosed but cross-linking is necessary to elicit a respiratory burst
Authors: Stewart Wilson W , Mazengera Ronald L , Shen Li , Kerr Michael A
Published: January 2018

My43 is a monoclonal antibody directed against FcαRs on monocytes that also recognizes neutrophil (PMN) FcαRs and is able to elicit a respiratory burst in purified cells. It appears to be directed against the immunoglobulin A (IgA) binding site of FcαRs or an epitope in close proximity, since IgA and My43 compete for binding to PMNs. My43 immunoblotted FcαR that had been affinity purified from PMN membranes and immunoprecipitated a 50–70 kDa protein from radiolabeled PMN membranes, apparently identical to that purified on IgA-Sepharose. These results suggest the presence of a single class of FcαR on PMNs. Binding of unaggregated monomeric or dimeric serum IgA to FcαRs on PMNs occurs at physiological concentrations, suggesting that in vivo FcαRs are saturated with ligand. This binding does not elicit a respiratory burst. Purified PMNs do not express surface IgA, since receptor-bound IgA is lost from the cell surface by endocytosis at room temperature although not at 4°. Rapid endocytosis of receptor-bound IgA has been demonstrated by flow cytometry and confocal microscopy. Unoccupied receptor that is able to bind IgA or My43 is subsequently reexpressed. Cross-linking of surface-bound IgA using F(ab’)2 anti-α chain antibodies triggers an oxidative burst. After internalization of the surface IgA the same F(ab’)2 anti-α chain antibodies do not trigger the burst. J. Leukoc. Biol. 56: 481–487; 1994.
Jacalin, a lectin that inhibits in vitro HIV-1 infection, induces intracellular calcium increase via CD4 in cells lacking the CD3/TcR complex
Authors: Lafont Virginie , Dornand Jacques , d’Angeac Arnaud Dupuy , Monier Serge , Alcover Andrès , Favero Jean
Published: January 2018

The lectin jacalin interacts with the CD4 cell surface antigen; this lectin inhibits in vitro infection by human immunodeficiency virus type 1 without preventing virus binding on the host cell. The infection process is known to involve cellular events triggered by the binding of the viral external glycoprotein gp120 to CD4. Herein we demonstrate that jacalin induces cell signaling directly through the CD4 antigen and that independently of the CD3/TcR complex. The capacity of jacalin to trigger cell signals through the CD4 molecule is discussed in relation to its ability to inhibit HIV infection. J. Leukoc. Biol. 56: 521–524; 1994.
The role of diacylglycerol and ceramide in tumor necrosis factor and interleukin-1 signal transduction
Authors: Schütze Stefan , Machleidt Thomas , Krönke Martin
Published: January 2018

Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are cytokines with pleiotropic biological activities, exerting a broad range of overlapping biological functions. The redundancy of TNF and IL-1 activities may be based on the utilization of shared key components of intracellular signaling pathways. Two lipid second messengers have been found to transmit TNF and IL-1 intracellular signals: 1,2-diacylglycerol (DAG), generated by a phosphatidylcholine-specific phospholipase C, and ceramide, generated by sphingomyelinase (SMase). DAG is a well established activator of the important signaling system protein kinase C (PKC), which appears to mediate various cellular responses to TNF or IL-1. In addition, it is obvious that DAG also activates other enzyme systems like acidic sphingomyelinase. SMases have been implicated in a number of TNF responses, including stimulation of cell growth and differentiation, as well as triggering cytotoxicity and apoptosis. The metabolic active cleavage product of SMase, ceramide, is a novel multifunctional lipid second messenger capable of inducing various signaling systems. Both cytokines, TNF and IL-1, stimulate a neutral, plasma membrane-associated SMase that leads to stimulation of a protein kinase and eventually to activation of the mitogen-activated protein (MAP) kinase cascade and phospholipase A2. Ceramide is also capable of stimulating a cytosolic protein phosphatase. PKC plays a role in activation of the nuclear transcription factor AP-1, and the DAG-regulated acidic SMase is involved in transducing TNF signals to the cell nucleus via activation of the nuclear transcription factor NF-xB. J. Leukoc. Biol. 56: 533–541; 1994.
Multiple functions of nitric oxide in pathophysiology and microbiology: analysis by a new nitric oxide scavenger
Authors: Maeda Hiroshi , Akaike Takaaki , Yoshida Masaki , Suga Moritaka
Published: January 2018

A wide range of biological functions of nitric oxide (NO) was analyzed using a newly discovered nitric oxide scavenger, 2-phenyl-4,4,5,5-tetramethylimidazolineoxyl-l-oxyl-3-oxide (PTIO) or its water-soluble derivative carboxy-PTIO. The chemistry is very simple in that NO was oxidized by PTIO, yielding one mole each of NO2 and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl. Based on the potent NO-scavenging activity of PTIO derivatives, the diverse functions of NO under physiological states as well as various pathological conditions such as endotoxin shock and viral diseases are now explicated. It was found that PTIO and carboxy-PTIO showed significant inhibitory activity against a series of biological actions of NO: (1) endothelium-dependent vascular relaxation in an ex vivo system, (2) pathogenicity of NO produced excessively in endotoxin shock in rats and in influenza virus pneumonitis in mice, and (3) enhanced vascular permeability in solid tumors mediated by NO. PTIO directly extinguishes NO generated by NO synthase (NOS) without affecting NOS activity, which is a clear contrast to NOS inhibitors. Therefore, characterization of this unique mode of action of PTIO appears to be helpful not only in understanding of the pathophysiological role of NO but also in the treatment of various diseases caused by excessive production of NO. J. Leukoc. Biol. 56: 588–592; 1994.
Summary of the 5TH International Congress on TNF and related cytokines: scientific advances and their medical applications1
Authors: Beutler Bruce
Published: January 2018

Ten years ago, a new field emerged with the isolation and cloning of tumor necrosis factor (TNF), an exceptionally pleiotropic cytokine that seemed to promise an effective treatment for cancer. The field drew a heavy following from the existing disciplines of immunology, oncology, endocrinology, hematology, and infectious disease research as it was recognized that the actions of TNF were relevant to each. The first International Congress on TNF and Related Cytokines was held in Heidelberg in 1986, and subsequent congresses were held in Napa, Chiba, and Veldhoven. This, the 5th Congress, was held at the Asilomar Conference Center in Monterey.
Lymphocyte-mediated nitric oxide production by rat endothelial cells
Authors: Shuler Randy L , Laskin Debra L , Gardner Carol R , Feder Lisa S , Laskin Jeffrey D
Published: January 2018

Lymphocyte migration from the blood to sites of tissue injury is mediated, in part, through the interaction of these cells with endothelial cells lining the vessel walls. The ability of endothelial cells to produce nitric oxide may be important in this process. We found that the addition of the nonspecific lymphocyte activators lipopolysaccharide (LPS) or concanavalin A (Con A) to rat hepatic endothelial cell cultures from control or endotoxemic rats markedly enhanced the ability of these cells to produce nitric oxide. In contrast, wheat germ agglutinin (WGA) and phytohemagglutinin (PHA) had no effect on nitric oxide release. Coculture of endothelial cells with lymphocyte-rich preparations of rat thymocytes or splenocytes stimulated endothelial cell nitric oxide production. This response was enhanced by LPS or Con A and to a lesser extent by WGA or PHA. In contrast to endothelial cells, thymocytes and splenocytes did not produce nitric oxide either in the presence or absence of lymphocyte mitogens. Increased production of nitric oxide by endothelial cells in response to lymphocytes and lymphocyte mitogens was due, at least in part, to increased expression of protein for an inducible form of nitric oxide synthase, as measured by Western blotting. Stimulation of endothelial cell nitric oxide production by thymocytes and splenocytes was inheritable by the specific nitric oxide synthase inhibitor NG-monomethyl-L-arginine and dependent on cell-cell contact. Thus, nitric oxide production by endothelial cells was reduced when the lymphocytes were physically separated from the endothelial cells using cell culture inserts. We hypothesize that nitric oxide released by endothelial cells increases vascular permeability, thereby allowing the extravasation of lymphocytes into the surrounding tissue, a process that may be important in inflammation, tissue injury, and/or wound healing. J. Leukoc. Biol. 57: 116–121; 1995.
Immunohistochemical expression of inducible nitric oxide synthase (iNOS) in reversible endotoxic shock studied by a novel monoclonal antibody against rat iNOS
Authors: Sato Kiminori , Miyakawa Kazuhisa , Takeya Motohiro , Hattori Ryuichi , Yui Yoshiki , Sunamoto Mie , Ichimori Yuzo , Ushio Yukitaka , Takahashi Kiyoshi
Published: January 2018

An antirat monoclonal antibody (mAb) against inducible nitric oxide synthase (iNOS), ANOS11, was used for immunohistochemistry to examine the expression of iNOS in various organs and tissues of adult rats in experimental endotoxic shock induced by lipopolysaccharide (LPS) injection. The phenotype of iNOS-expressed cells was also examined immunohistochemically using various mAbs. In control rats, very few cells were positive for ANOS11 except in the thymus. After intravenous injection of LPS, the number of iNOS-positive cells increased rapidly in almost all organs, except the thymus and brain, peaked 6 h after the injection, and decreased slowly. Of the numerous inflammatory cells that infiltrated the lungs, liver, and spleen after LPS injection, many were positive for ANOS11. Besides inflammatory cells, hepatocytes and endothelial cells of the aorta were also positive for ANOS11 but only around 6 h after injection. The cellular composition of iNOS-positive infiltrated cells changed along with the progression of endotoxic shock. At 4 to 6 h after injection, most iNOS-positive cells were considered polymorphonuclear leukocytes judging by their positive reactivity to 0X42 and their nuclear morphology. The population of iNOS-positive macrophages positive for EDI or ED2 increased with time. After 24 h, many iNOS-positive macrophages were found around the focal necrosis in the liver and spleen. These results indicate that the expression of iNOS in neutrophils, endothelial cells, and hepatocytes precedes that of macrophages in experimental endotoxic shock. The expression of iNOS in various cells and organs is closely associated with the progress and pathological changes of endotoxic shock. J. Leukoc. Biol. 57: 36–44; 1995.
Heterodimers of the calcium-binding proteins MRP8 and MRP14 are expressed on the surface of human monocytes upon adherence to fibronectin and collagen. Relation to TNF-α, IL-6, and superoxide production
Authors: Mahnke Karsten , Bhardwaj Ranjit , Sorg Clemens
Published: January 2018

The 27E10 antigen is a heterodimer of MRP8 and MRP14, two Ca2+-binding proteins related to the S-100 protein family. Previous studies have shown that 27E10 epitope–bearing monocyte subsets are prevalent in early acute but absent in chronic inflammatory conditions. These observations further provide an impetus for identifying the cellular mechanisms responsible for the appearance of different monocyte subpopulations during inflammation. Therefore this in vitro study was carried out to investigate the influence of adhesion in inducing 27E10-positive subsets. In adhesion assays the role of 27E10 antigen in spontaneous adherence was obvious, as a monoclonal antibody directed against the 27E10 antigen significantly inhibited the adherence of monocytes to collagen and fibronectin. In contrast, these extracellular matrix (ECM) proteins induce the cell surface expression and association of 27E10 antigen with cytoskeleton (CSK), detected by flow cytometry and confocal laser scan microscopy, respectively. Similar results were obtained on cross-linking with specific antibodies, thus showing involvement of the integrin molecules VLA-2 and VLA-4. In addition, the association with CSK could be confirmed by differential detergent extraction. The observed redistribution of 27E10 antigen guided by collagen compared with fibronectin was also paralleled by an augmented release of inflammatory cytokines interleukin-6, tumor necrosis factor α, and superoxide anions. Thus, this study demonstrates that under inflammatory conditions the interactions of extravasating monocytes with the ECM may induce an activated phenotype of monocytes marked by 27E10. J. Leukoc. Biol. 57: 63–71; 1995.
The endoperoxides/TxA2 analogue, U46619, inhibits human polymorphonuclear leukocyte function
Authors: Rotondo Serenella , Celardo Antonio , Evangelista Virgilio , Cerletti Chiara
Published: January 2018

The effects of the stable analogue of TxA2, U46619, on polymorphonuclear leukocyte (PMN) function were investigated. U46619, at micromolar concentrations, inhibited fMLP-stimulated aggregation, β-glucuronidase release, and superoxide production. fMLP-induced LTB4 synthesis was also inhibited. U46619 did not modify intracellular Ca2+ increase induced by fMLP in Fura-2-loaded PMN, suggesting that early events of cell activation were not involved. In fact, U46619 also inhibited aggregation, β-glucuronidase release, superoxide anion and LTB4 production induced by the calcium ionophore A23187. By comparison with the specific 5-lipoxygenase inhibitor, L-663,536, which prevented LTB4 synthesis without affecting degranulation, we excluded the impairment of PMN function by U46619 as a consequence of the reduction of this endogenous agonist. TLC separation of lipid extracts from [3H]-AA-loaded PMN, stimulated by A23187, showed significant reduction of the radioactivity associated with authentic free AA, suggesting that U46619 could interfere with mechanisms regulating AA release from membrane phospholipids. This suggestion is also supported by the observation that manoalide, a standard inhibitor of phospholipase A2, similarly to U46619, inhibits β-glucuronidase release from stimulated PMN. Prostaglandin endoperoxides, produced by cells participating in inflammatory reactions, might therefore play a role in modulating PMN activities. J. Leukoc. Biol. 57: 72–79; 1995.
Delayed-type hypersensitivity to a recombinant mycobacterial antigen, MPB64, in guinea pigs sensitized to Mycobacterium tuberculosis or Mycobacterium bovis BCG
Authors: Haga Shinji , Yamaguchi Ryuji , Nagai Sadamu , Matsuo Kazuhiro , Yamazaki Akihiro , Nakamura Reiko M
Published: January 2018

Recombinant MPB64 (rMPB64), a mycobacterial antigen, was obtained from an Escherichia coli clone transformed with a recombinant expression vector, pMAL64c. The rMPB64 was examined for the activity to elicit delayed-type hypersensitivity (DTH) in guinea pigs injected with live Mycobacterium tuberculosis H37Rv or live M. bovis BCG Tokyo. It was found that rMPB64 has the same reactivity as native MPB64 (nMPB64) or MPT64 (nMPT64) and the potency to elicit DTH was 13.4 times higher than that of PPD. Because MPB64 is secreted only by living M. tuberculosis and some strains of BCG, it is possible to use this antigen for the diagnosis of tuberculosis. J. Leukoc. Biol. 57: 221–225; 1995.
Modulation of rat neutrophil functions by administration of granulocyte colony-stimulating factor
Authors: Murata Kotaro , Watanabe Tadashi , Yamashita Takao , Gon Songi , Sendo Fujiro
Published: January 2018

Neutrophil function was examined in rats treated with recombinant human granulocyte colony-stimulating factor (G-CSF) using peripheral blood neutrophils (PBNs) and peritoneal exudate neutrophils (PENs) as sources of cells examined in vitro. Adherence to plastic plates containing fetal calf serum of nonstimulated or N-formylmethionyl-leucyl-phenylalanine (fMLP)- or tumor necrosis factor-α-stimulated PBNs obtained from G-CSF-injected rats was lower than that of control rats. In contrast, this adherence was higher in G-CSF-treated rats than in the control group when PENs were used. Neutrophil adherence of G-CSF-injected and noninjected groups was identical when phorbol myristate acetate was used to stimulate neutrophils. Superoxide production of PBNs stimulated with fMLP in vitro was lower in G-CSF-treated rats than in control rats but higher than in the controls when PENs were used. Furthermore, in vitro tumor cell growth inhibition by PBNs was lower in G-CSF-treated rats than in control rats, but when PENs were used inhibition was higher than in the controls. J. Leukoc. Biol. 57: 250–256; 1995.
An inhibitor of polyamine biosynthesis impairs human polymorphonuclear leukocyte priming by tumor necrosis factor α
Authors: Walters John D , Cario Anthony C , Leblebicioglu Binnaz , Fernandez Marilyn C , Marucha Phillip T
Published: January 2018

TNF primes polymorphonuclear leukocytes (PMNs) for enhanced oxidative and secretory activity and directly induces adhesion and IL-1β expression. Previous reports suggest that polyamine biosynthesis by ornithine decarboxylase (ODC) has an essential role in macrophage activation by TNF. In the current study, TNF induced rapid increases in the putrescine and spermine content of PMNs. Difluoromethylornithine (DFMO), a selective inhibitor of ODG, inhibited these increases and blunted the enhancement of superoxide generation and secondary granule release associated with priming by TNF. DFMO did not affect the expression of TNF receptors or block receptor-independent activation of the respiratory burst by phorbol esters. Moreover, DFMO did not antagonize induction of adhesion or IL-1β mRNA expression by TNF. Thus, polyamine biosynthesis plays an important role in priming by TNF, but is not involved in all PMN responses to this cytokine. This suggests that ODC is a potential target for selective chemotherapeutic modulation of the inflammatory response. J. Leukoc. Biol. 57: 282–286; 1995.
Expression of cytokine mRNA in murine splenic dendritic cells and better induction of T cell-derived cytokines by dendritic cells than by macrophages during in vitro costimulation assay using specific antigens
Authors: Kanangat Sivadasan , Nair Smita , Babu John Sam , Rouse Barry T
Published: January 2018

Among antigen-presenting cells dendritic cells (DC) have the unique ability to generate primary T cell response. The reasons for the superior inductive property of DC still remain obscure. The explanations offered include higher expression of CD80, MHCII, and ICAMI on DC surface which allows effective cluster formation with T cells. It is also possible that additional cellular characteristics of DC, i.e., their ability to release critical mediators involved in the induction of effective immune response, are important. We examined the ability of DC to express IL-1, IL-6, and IL-12 using the highly sensitive reverse transcription-quantitative polymerase chain reaction. Our data show that highly purified (97–99% pure) murine splenic DC were capable of expressing IL-1, IL-6 and IL-12 mRNA upon stimulation with lipopolysaccharide. We also compared the ability of DC and macrophages to induce T cell-derived cytokines IL-2 and IFN-γ in an in vitro antigen-specific costimulation assay. In naive T cells stimulated with antigen presented via DC or macrophages, the levels of mRNA for IL-2 and IFN-γ were 2- to 4-fold higher when cells were stimulated with DC. Overall, our data add additional support to the description of DC as superior antigen-presenting cells for the activation of naive T cells. J. Leukoc. Biol. 57: 310–316; 1995.
Neutrophil activation by anti-β2 glycoprotein I monoclonal antibodies via Fcγ receptor II
Authors: Arvieux Josiane , Jacob Marie-Christine , Roussel Bernard , Bensa Jean-Claude , Colomb Maurice G
Published: January 2018

Murine monoclonal antibodies (mAbs) to human β  2-glycoprotein I (β  2GPI), a plasma protein required for the binding of some antiphospholipid antibodies, have been shown to possess lupus anticoagulant properties and to activate platelets via Fcγ receptor (FcγR) crosslinking. Here we investigated their ability to induce polymorphonuclear leukocyte (PMN) functional responses. The six mAbs (IgGl isotype) tested in combination with β  2GPI led to a concentration-dependent activation of human PMNs as appreciated by granule release, H2O2 production, and cytosolic Ca2+ increase. This activation process was accompanied by the enhancement of PMN-mediated heparan sulfate loss from the endothelial cell line EA.hy 926 without evidence for cell lysis or detachment. F(ab’)2 fragments of one of the mAbs bound to PMNs in a β  2GPI-dependent manner but were devoid of activating effects. Carbamylated β  2GPI was unable to mediate PMN-antibody binding and subsequent activation. In addition, cationization of β  2GPI or removal of its sialic acid groups led to higher efficiency in binding to the PMN surface and triggering activation in comparison with the untreated protein. Thus, the process of PMN activation depends on mAb binding to these cells through both Fab (via β  2GPI) and Fc domains, as confirmed by the suppression of all responses upon treatment with an anti-FcγRII, but not anti-FcγRIII, antibody. Our data suggest a model of cellular activation by β  2GPI-dependent antiphospholipid antibodies. J. Leukoc. Biol. 57: 387–394; 1995.
Retinoic acid inhibits basal and interferon-γ-induced expression of intercellular adhesion molecule 1 in monocytic cells
Authors: Weber Christian , Calzada-Wack Julia C , Goretzki Michael , Pietsch Angelika , Johnson Judith P , Ziegler-Heitbrock H W Löms
Published: January 2018

Retinoic acid (RA) and 1,25-(OH)2-vitamin D3 (1,25-D3) induced U937 cell maturation into distinct monocytic phenotypes, as demonstrated by up-regulation of CD23 by RA and CD14 by 1,25-D3. Differentiation by RA but not by 1,25-D3 was associated with reduction of basal and complete suppression of interferon-γ (IFN-γ)–stimulated intercellular adhesion molecule 1 (ICAM-1) expression. Induction of cyclooxygenase activity by RA and attenuation of basal ICAM-1 expression exhibited similar kinetics. Treatment with indomethacin prevented and prostaglandin E2 (PGE2), dibutyryl-cAMP, or forskolin mimicked reduction of basal ICAM-1 expression by RA, indicating that this effect of RA is mediated by PGE2 synthesis and subsequent cAMP elevation. In contrast, suppression of IFN-γ-induced ICAM-1 expression by RA was only partly reversible by indomethacin, suggesting that inhibition of IFN-γ stimulation was not completely due to cyclooxygenase induction. RA did not always counteract IFN-γ, as it cooperated with IFN-γ in down-regulating very late activation antigen 4. Specific polymerase chain reaction and Northern blotting of ICAM-1 mRNA revealed that RA suppressed ICAM-1 induction by IFN-γ at the transcriptional level. RA also blocked ICAM-1 induction by IFN-γ in isolated human blood monocytes. In conclusion, inhibition of basal and stimulated ICAM-1 expression in monocytic cells may provide a mechanism for beneficial anti-inflammatory effects of retinoids. J. Leukoc. Biol. 57: 401–406; 1995.
T cells and HIV-induced T cell syncytia exhibit the same motility cycle
Authors: Sylwester Andrew , Shutt Damon , Wessels Deborah , Stapleton Jack T , Stites Jan , Kennedy Ronald C , Soil David R
Published: January 2018

Ameboid cells ranging in complexity from Dictyostelsum amebas to human polymorphonuclear leu kocytes (PMNs) translocate in a cyclical fashion. Using computer-assisted motion analysis, we have analyzed the motility of human lymphocytes of the immortal SupTl cell line and of a peripheral blood mononuclear cell popu lation highly enriched for CD4-positive cells (CD4-enriched PBMCs) on four substrates—plastic, dehydrated rat tail collagen, hydrated rat tail collagen, and bovine aortic en dothelium. In addition, we have analyzed the motility on these substrates of syncytia induced by human immuno deficiency virus (HIV) in cultures of both cell types. It is demonstrated that both SupTl cells and CD4-enriched PBMCs exhibit a motility cycle with a period of 1.6 min that is independent of substrate, independent of average cell velocity, and similar to the periods of translocating Dictyostelium amebas and PMNs. More surprisingly, it is demonstrated that HIV-induced SupTl and PBMG syn cytia with volumes 10 to 100 times those of single cells ex hibit the same motility cycle as their single-cell progeni tors. These observations support the generality of the motility cycle in animal cells and, for the first time, demonstrate that the cycic is independent of cell size. J. Lcukoc. BioL 57; 643–650; 1995.
CD30 and type 2 T helper (Th2) responses
Authors: Romagnani Sergio , Del Prete Gianfranco , Maggi Enrico , Chilosi Marco , Caligaris-Cappio Federico , Pizzolo Giovanni
Published: January 2018

CD30 is one of the members of the tumor necrosis factor receptor superfamily, originally described as a marker of Reed-Sternberg and Hodgkin’s cells in Hodgkin’s lymphoma. CD30 appears to be preferentially expressed on, and its soluble form (sCD30) released by, CD4+ and CD8+ T cell clones capable of producing T helper 2 (Th2)-type cytokines. In nonneoplastic conditions, CD30+ T cells are barely detectable in vivo; however, a few allergen-specific CD4+CD30+ T cells inducible to the production of Th2-type cytokines could be sorted out from the circulation of allergic subjects after allergen exposure. Moreover, high numbers of CD30+ T cells were found in the lymph node of a patient suffering from Omenn’s syndrome, a rare congenital Th2-mediated immunodeficiency disorder. More importantly, high serum levels of sCD30 were observed in some conditions in which a pathogenetic role for Th2 cells has been suggested, such as Omenn’s syndrome, atopy, systemic lupus erythematosus, and after infection with measles virus or human immunodeficiency virus. Thus, detection of CD30+ T cells and/or of increased levels of sCD30 may reflect the presence of immune responses or immune alterations characterized by the prevalent activation of Th2-like cells. J. Leukoc. Biol. 57: 726-730; 1995.
Matrix metalloproteinases and processing of pro-TNF-α
Authors: Gearing A J H , Beckett P , Christodoulou M , Churchill M , Clements J M , Crimmin M , Davidson A H , Drummond A H , Gallowav W A , Gilbert R , Gordon J L , Leber T M , Mangan M , Miller K , Nayee P , Owen K , Patel S , Thomas W , Wells G , Wood L M , Woolley K
Published: January 2018

Tumor necrosis factor-α (TNF-α) is released from a cell membrane-anchored precursor by proteolytic cleavage. We have shown that broad spectrum synthetic inhibitors of matrix metalloproteinases (MMPs) prevent the processing of the TNF precursor but do not inhibit the release of other cytokines. Purified MMPs, stromelysin, matrilysin, collagenase, and the gelatinases can all cleave a recombinant pro-TNF substrate to yield mature TNF. MMP inhibitors prevent the rise in blood levels of TNF after endotoxin administration in rats and are effective in animal models of inflammatory disease such as adjuvant arthritis. Drugs that inhibit MMP action and TNF release show great promise for the treatment of autoimmune inflammatory diseases. J. Leukoc. Biol. 57: 774–777; 1995.
Bicarbonate and phosphate ions protect transferrin from myeloperoxidase-mediated damage
Authors: Edeker Brian L , Rasmussen George T , Britigan Bradley E
Published: January 2018

Exposure to hypochlorous acid (HOC1), the main product of the reaction of neutrophil myeloperoxidase (MPO), H2O2, and Cl-, reportedly decreases apotransferrin’s iron binding capacity. Optimal transferrin iron binding requires the coexistent binding of anions such as bicarbonate (HCO3-) near the protein’s two iron binding sites. Recently, we found that if HCO3- was also present during HOC1 exposure, apotransferrin retained its ability to inhibit iron-catalyzed hydroxyl radical generation. Therefore, we examined apotransferrin iron binding capacity after exposure to the MPO/H2O2/I- system in the presence and absence of several anions (HCO3-, H2PO4-, SO42-, and ClO4-) known to bind to apotransferrin. Although the MPO system decreased apotransferrin iron uptake to only 46% of the untreated apotransferrin control, apotransferrin treated in the presence of 1 mM HCO3- or H2PO4- retained 84 and 74%, respectively, of its iron binding capacity. Similar results were seen when apotransferrin was treated with NaOCl. These results could not be explained on the basis of a loss of MPO activity or scavenging of HOCl. In contrast, SO42- and ClO4- were unable to prevent the MPO-mediated loss of apotransferrin iron binding capacity. NaOCl had no effect on the ability of transferrin to bind any of these anions, as assessed by the anion-induced change in apotransferrin absorbance spectrum. HCO3- but not H2PO4-, SO42-, or ClO4- decreased MPO-mediated oxidation (iodination) of apotransferrin. Under some conditions H2PO4- actually increased apotransferrin iodination. HCO3- and H2PO4- may protect apotransferrin from MPO-mediated oxidative damage by preventing selective oxidation of one or both iron binding sites. This process may allow transferrin to retain its iron binding function during MPO exposure in vivo. J. Leukoc. Biol. 58: 59–64; 1995.
CD4+ contrasuppressor T cells improve the resistance of thermally injured mice infected with HSV
Authors: Kobayashi Makiko , Hemdon David N , Pollard Richard B , Suzuki Fujio
Published: January 2018

Modulation of burn-associated CD8+ CD11b+ T cell receptorγ/δ+ suppressor T cells (BA2T cells) and improved resistance to herpesvirus infections was studied in thermally injured mice. The susceptibility of thermally injured mice to infection by herpes simplex virus (HSV) was approximately 100 times greater than it was in normal mice. The increased susceptibility of thermally injured mice to HSV infection was transferred to normal mice by BA2T cells, which appeared in spleens of mice 2–9 days after thermal injury. The suppressor cell activity of BA2T cells was effectively counteracted by CD4+ CD28+ T cell receptorα/β+  Vicia villosa lectin adherent antisuppressor cells (designated as bum-induced contrasuppressor T cells; BCS cells), which were generated naturally in spleens of mice after the appearance of BA2T cells. The adoptive transfer of BCS cells to mice just after the injury improved the resistance of thermally injured mice to HSV infection to levels observed in normal mice. These results suggest that the increased susceptibility of thermally injured mice to HSV infection may be affected by BA2T suppressor cells and BCS cells may improve the resistance of thermally injured mice to HSV infection through the inhibition of BA2T suppressor cell activities. J. Leukoc. Biol. 58: 159–167; 1995.
Migration of distinct subsets of CD8+ blood T cells through endothelial cell monolayers in vitro
Authors: Berman Jeffrey S , Mahoney Kathleen , Saukkonen Jussi J , Masuyama Junichi
Published: January 2018

The immune response in many infections and to allografts is dependent on CD8+ cytotoxic T lymphocytes (CTL). Influx of CD8+ CTL from the blood has been documented during antigen challenge. We have previously found that a subset of CD8+ T cells from normal blood can migrate through endothelial cell monolayers in vitro. To further characterize migration-prone CD8+ T cells from normal blood, we examined the expression of CD28 and a restricted epitope of CD18/CD11a (S6F1), a CTL marker. Although normal blood CD8bright+ T cells were heterogeneous in their expression of CD28, three populations could be identified (CD28low, CD28moderate, and CD28high). CD8+ cells migrating across endothelial cell monolayers were enriched for CD8bright+ CD28high cells and a subset of CD8dim+ cells, which were CD28high. Both adherent and migrating CD8+ cells were exclusively (>95%) S6F1high. There was also preferential adhesion and migration of CD8+ cells expressing the low-molecular-weight form of the leukocyte common antigen, CD45RO. Cytokine activation of the endothelium did not significantly alter preferential migration of these subsets. These data suggest that certain subsets of CD8+ memory T cells in normal human blood are prone to, adhere to, and migrate through allogeneic endothelial cells and would thus be likely to be recruited to sites of antigen challenge.
Desensitization of the actin polymerization response in human neutrophils at low cell density
Authors: Model Michael A , Omann Geneva M
Published: January 2018

Many chemoattractant-activated responses in neutrophils show transient kinetics, suggesting that rapid desensitization occurs during the time course of the response. We found that desensitization of the actin polymerization response to N-formyl peptides is, in a large part, due to inhibition by adenosine released from cells to the medium and depletion or a chemical inactivation of the agonist. To reduce the influence of these factors, we stimulated neutrophils in a very diluted suspension, sometimes with continuous replacement of the medium. The actin polymerization response to a high agonist concentration was greatly enhanced and prolonged under these conditions, often without any tendency to subside within 10 min at 25°C. It has previously been shown that the N-formyl peptide receptor converts from a rapidly dissociating to a slowly dissociating and presumably inactive form during activation. Under the conditions of low cell concentration, the conversion to a slowly dissociating receptor still occurred. Thus the prolonged response was not due to prolonged presence of rapidly dissociating receptors. We conclude either that a low number of rapidly dissociating receptors, which we failed to see, is sufficient to maintain actin polymerization or that slowly dissociating receptors can support the actin response. In contrast to responses stimulated by high agonist concentrations, the responses to low concentrations of the agonists were transient. The results of other authors indicate that low concentrations of N-formyl peptides do not desensitize the receptors. Other mechanisms, which are specific for the actin polymerization response, must be involved in response termination to low concentrations of N-formyl peptides. Activation at low cell density will be a useful approach for studying other processes (Ca2+ elevation, oxidant production, etc.) and chemoattractants (leukotriene B4, interleukin 8, etc.) for which an understanding of the kinetics due to desensitization of the components of the receptor-mediated activation pathway is desired.
Inhibition of superantigen-induced T cell proliferation and monocyte IL-1β, TNF-α, and IL-6 production by acute ethanol treatment
Authors: Szabo Gyongyi , Mandrekar Pranoti , Catalano Donna
Published: January 2018

Alcohol use has been shown to decrease monocyte antigen presentation capacity and inflammatory cytokine production, thereby increasing susceptibility to infections. Here, we demonstrate that in vitro acute treatment of normal monocytes with pharmacological doses of ethanol can decrease superantigen [Staphylococcus enterotoxins B (SEB) and A (SEA)]-induced T cell proliferation. Furthermore, ethanol treatment (25–100 mM) significantly inhibited SEA- or SEB-induced production of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 in monocytes. Ethanol-induced down-regulation of monocyte TNF-α, IL-1β, and IL-6 occurred at both the protein and mRNA levels. Additional data suggest that ethanol can decrease IL-1β mRNA stability. Furthermore, experiments using cycloheximide indicate that de novo protein synthesis is required for the inhibitory effect of ethanol on SEB-induced IL-1β mRNA production. Finally, ethanol treatment decreased HLA-DR expression in monocytes, suggesting that ethanol treatment can compromise monocyte stimulation by down-regulating the SEB-binding capacity of monocytes. These results suggest that acute ethanol treatment can interfere with monocyte activation by SEB at multiple steps. Consequently, decreased superantigen-induced polyclonal T cell activation and inflammatory monokine production would contribute to an impaired immune response to bacterial challenge with superantigens after acute alcohol intake.
Monomeric human IgE evokes a transient calcium rise in individual human neutrophils
Authors: Collison Kate S , Kvvaasi Aaron A A , Parhar Ranjit S , Al-Sedairy Sultan T , Al-Mohanna Futwan A A
Published: January 2018

Digital fluorescence calcium imaging was used to investigate and identify the primary biological responses of human neutrophils to monomeric immunoglobulin E (IgE). Treatment of neutrophils with IgE caused a transient rise in the level of intracellular calcium that was inhibited by pertussis toxin. The calcium rise was due mainly to release from an intracellular membrane-enclosed store that is also sensitive to the chemotactic peptide formyl-Met-Leu-Phe. The IgE-induced calcium transient was independent of Fcγ receptors and of Fc receptor ligation. Our data suggest that the mere binding of IgE to neutrophils is sufficient to evoke a biological response without the need for IgE/receptor cross-linking.
Regulation of N-formyl-methionyl-leucyl-phenylalanine receptor recycling by surface membrane neutral endopeptidase–-mediated degradation of ligand
Authors: Painter Richard G , Aiken Martha L
Published: January 2018

Neutrophil responses to α-N-formyl-L-Met- L-Leu-L-Phe (fMLF) are modulated by inhibitors of surface membrane neutral endopeptidase (NEP), such as phosphoramidon (PPAD). Because receptor recycling is presumably required for a sustained cellular response, the effect of PPAD on receptor reexpression was examined. After down-regulation of surface fMLF receptors by fMLF, PPAD blocked the normal reexpression of surface receptors in a manner that was related to the time of prior exposure to fMLF. Internalized fML[3H]F was hydrolyzed by NEP at a rate comparable to the rate of receptor reexpression at the cell surface, suggesting that ligand hydrolysis is rate limiting. To test this hypothesis, cells were incubated with fluorescein-labeled formyl-Met-Leu-Phe-Nle-Tyr-Lys at 15°C. After binding was complete, but before internalization of receptor-ligand complexes, high-affinity antifluorescein antibody F(ab’)2 fragments were added and the cells incubated at 37°C for 60 min in the presence of PPAD. Under these conditions, the inhibitory effects of PPAD were largely reversed and nonimmune F(ab’)2 fragments were without effect.
A role for a 70-kDa amino-terminal fibronectin fragment in supporting soluble gelatin interactions with rat peritoneal macrophages
Authors: Penc S F , Blumenstock F A , Kaplan J E
Published: January 2018

Seventy-kilodalton amino-terminal and 180-kDa cell-binding fibronectin fragments were used to determine which fibronectin domains support soluble gelatin interactions with macrophages. At each time measured, intact and 180-kDa fibronectin supported significantly larger quantities of cell-associated gelatin than control levels (P < 0.05). Throughout the time course fibronectin supported more binding than 180 kDa. Seventy kilodalton did not augment gelatin binding until 2 h, but by 6 h 70 kDa supported more binding than intact fibronectin (P < 0.01). This appeared to result from a cellular response initiated by 70-kDa-gelatin interactions with the macrophages. Within 4 h the majority of gelatin associated with cells under control conditions, and in the presence of fibronectin or 180 kDa, was internalized. Seventy-kilodalton-mediated binding remained localized primarily to the cell surfaces at all times. The macrophages partially degraded the internalized and external gelatin fractions. These results demonstrate that intact fibronectin and specific fibronectin fragments support soluble gelatin interactions with macrophages.
The amyloidogenic peptide human amylin augments the inflammatory activities of eosinophils
Authors: Horn Joanne T , Estridge Tom , Pechous Penni , Hyslop Paul A
Published: January 2018

The amyloidogenic peptides, amyloid-β (Aβ) and human amylin, are the major constituents of amyloid deposits found in patients with the chronic degenerative disorders Alzheimer’s disease (AD) and type 2 diabetes, respectively. Recent studies have shown that a variety of inflammatory proteins such as cytokines are associated with the amyloid deposits of AD brain tissues. Therefore, in the present study, we sought to determine whether Aβ and/or human amylin could modulate the various inflammatory activities of eosinophils. We observed that human amylin but not Aβ peptides inhibited the in vitro interleukin-5 (IL-5)–mediated survival of cord blood–derived eosinophils (CBEs) in a concentration-dependent manner. By contrast, rat amylin, a nonamyloidogenic peptide that is highly homologous to human amylin, failed to affect the IL-5–mediated survival of CBEs. Similar inhibitory effects of human amylin were observed for peripheral blood eosinophils. Human amylin also enhanced the release of the cytokine granulocyte-macrophage colony-stimulating factor by CBEs that were stimulated with the calcium ionophore A23187 but was incapable of directly stimulating CBEs to release cytokines. In addition, the A23187-induced release of the inflammatory lipid mediator leukotriene C4 by CBEs was augmented by human amylin. These results suggest that the amyloidogenic peptide human amylin is capable of amplifying the various inflammatory activities of eosinophils.
Induction of a prenylated 65-kd protein in macrophages by interferon or lipopolysaccharide
Authors: Vestal Deborah J , Maki Richard A , Buss Janice E
Published: January 2018

Treatment of murine bone marrow-derived macrophages with interferon-γ (IFN-γ) and/or lipopolysaccharide (LPS) resulted in changes in the abundance of a number of prenylated proteins. The most significant change involved a protein of 65 kd (p65) that became one of the most abundant prenylated proteins following treatment. The 65-kd protein was induced by agents that stimulate macrophage activation (IFNs or LPS) but not by cytokines that promote macrophage proliferation, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), M-CSF, or interleukin-3. The majority of p65 was localized to subcellular fractions containing internal and plasma membranes but was not detected in nuclear membranes. The farnesyltransferase inhibitor BZA-5B caused a dramatic decrease in p65 prenylation, suggesting that this protein may be modified by the C15 isoprenoid farnesyl. These observations provide the first direct evidence that interferons and LPS cause changes in the abundance of specific isoprenoid-modified proteins in macrophages.
Diverse immunological and hematological effects of interleukin 7: implications for clinical application
Authors: Komschlies Kristin L , Grzegorzewski Krzysztof J , Wiltrout Robert H
Published: January 2018

Interleukin-7 (IL-7) was originally discovered to be a pre-B cell growth factor. Soon thereafter, a broader role for IL-7 in leukocyte development and function began to be identified. IL-7 now has been shown to be a critical cytokine for normal T and B lymphopoiesis and a mobilizer of pluripotent stem cells and myeloid progenitors. IL-7 has been demonstrated to enhance T cell function and induce cytokine expression in monocytes. Preclinical studies have already found that IL-7 could accelerate murine lymphocyte regeneration following chemotherapy and bone marrow transplantation, induce anti-tumor effects in mice, and expand anti-HIV-specific human T cells. Thus it is essential that further preclinical and clinical research be performed to evaluate IL-7 as a potential therapy for leukopenia, bone marrow/stem cell transplantation, cancer, and HIV/AIDS.
An analogue of lipid A and LPS from Rhodobacter sphaeroides inhibits neutrophil responses to LPS by blocking receptor recognition of LPS and by depleting LPS-binding protein in plasma
Authors: Aida Yoshitomi , Kusumoto Keisuke , Nakatomi Kensuke , Takada Haruhiko , Pabst Michael J , Maeda Katsumasa
Published: January 2018

When incubated with lipopolysaccharide (LPS) in the presence of plasma, neutrophils become primed for enhanced release of superoxide in response to triggering by formyl-Met-Leu-Phe (fMLP). The effect of LPS on phagocytes is inhibited by a synthetic lipid A precursor, LA-14-PP (lipid IVa) or by LPS from Rhodobacter sphaeroides (Rs). We studied the mechanisms by which LA-14-PP or Rs-LPS inhibited LPS-induced responses. When neutrophils were exposed to LA-14-PP or Rs-LPS for 3 min and then to Escherichia coli-LPS, the antagonists inhibited priming for superoxide release, and also blocked up-regulation of CD11b and adherence. This inhibition was dependent on plasma, was not overcome by higher amounts of E. coli-LPS or plasma, and was not observed at 0°C, suggesting that E. coli-LPS was not able to interact with its receptor or other cellular recognition molecule in neutrophils that had been exposed to the antagonists. The alternative possibility that LA-14-PP or Rs-LPS depleted a plasma cofactor, resulting in inhibition of priming, was investigated by using LPS from Porphyromonas gingivalis (Pg) and Bordetella pertussis (Bp). These LPS primed neutrophils in a plasma-dependent and CD14-dependent manner, but were not blocked by LA-14-PP or Rs-LPS. When sub-optimal concentrations of plasma were exposed to LA-14-PP or Rs-LPS, and then mixed with Pg-IPS or Bp-LPS, followed by incubation with neutrophils, priming and up-regulation of GD11b were inhibited, and this inhibition was overcome by increasing the concentration of plasma. Binding of LPS-binding protein (LBP) in plasma to immobilized E. coli-LPS was inhibited by pre-incubation of plasma with LA-14-PP or Rs-LPS. Together with the result that treatment of plasma with anti-LBP antibody abolished the cofactor activity of plasma, these results indicated that LA-14-PP and Rs-LPS depleted LBP from plasma, resulting in inability of LPS to act on neutrophils. Thus LA-14-PP and Rs-LPS inhibited the action of LPS on neutrophils by at least two mechanisms, blocking of LPS receptor recognition and depletion of the cofactor LBP.
Expression and regulation of chemokines in bacterial pneumonia
Authors: Standiford Theodore J , Kunkel Steven L , Greenberger Marc J , Laichalk Lauri L , Strieter Robert M
Published: January 2018

Effective host defense against bacterial invasion is characterized by the vigorous recruitment and activation of inflammatory cells, which is dependent on the coordinated expression of both pro-and anti-inflammatory cytokines. In this review, we present evidence indicating that both C-X-C and C-C chemokines are integral components of antibacterial host defense. Specifically, in vitro studies indicate that C-X-C chemokines [interleukin-8 (IL-8) and macrophage inflammatory protein 2 (MIP-2)] and the C-C chemokine macrophage inflammatory protein 1 alpha (MIP-1α) augment the ability of polymorphonuclear leukocytes (PMNs) and alveolar macrophages, respectively, to phagocytose and kill Escherichia coli. In addition, the intratracheal instillation of Klebsiella pneumoniae in CD-I mice results in time-dependent production of MIP-2 and MIP-1α, and the inhibition of MIP-2 bioactivity in vivo results in decreases in lung PMN influx, impaired bacterial clearance, and early mortality. Finally, the anti-inflammatory cytokine interleukin-10 (IL-10) is also expressed within the lung during the evolution of Klebsiella pneumonia, and neutralization of IL-10 in vivo results in enhanced proinflammatory cytokine production, bacterial clearance, and increases in both short- and long-term survival. In conclusion, our studies indicate that specific chemokines are important mediators of leukocyte recruitment and/or activation in bacterial pneumonia and that the expression of these chemokines is regulated by endogenously produced IL-10.