bluuebunny/crossref_metadata_2025 huggingface dataset:
Restoration of postburn impaired lymphocyte responsiveness by nonsteroidal anti-inflammatory drugs is independent of prostaglandin E2 inhibition
Authors: Mathieu Jacques , Masson Isabelle , Chancerelle Yves , Chanaud Brigitte , Strazlko Suzanne , De Sousa Martine , Kergonou Jean-François , Giroud Jean-Paul , Florentin Irene
Published: January 2018

Prostaglandin E2 (PGE2) has been implicated in postburn immunosuppression, which is responsible for septic complications. In the present work, seven nonsteroidal anti-inflammatory drugs (NSAIDs), differing by their capacity to inhibit the cyclooxygenase pathway, were compared for their ability to restore T lymphocyte proliferative responses evaluated 4 days after thermal injury in rats. Salicylic acid, 5-aminosalicylic acid, and niflumic acid, given daily, fully restored spleen cell responses to concanavalin A (Con A) and phytohemagglutinin. These drugs were active only at doses that were below the anti-inflammatory doses and did not modify normal spleen cell responses. In these conditions, indomethacin slightly restored lymphocyte reactivity, whereas acetylsalicylic acid, ketoprofene, and piroxicam were ineffective. PGE2 production by Con A-stimulated spleen cells from untreated burned rats and after treatment with niflumic acid or 5-aminosalicylic acid did not correlate with the intensity of the proliferative response. Indomethacin, niflumic acid, and 5-aminosalicylic acid were added in vitro to spleen cells from normal and burned rats, at concentrations from 10-7 to 10-4 M. PGE2 production was strongly depressed by indomethacin and niflumic acid and not modified by 5-aminosalicylic acid. The proliferative response of normal spleen cells was depressed in a concentration-dependent manner by niflumic acid and slightly inhibited at the highest concentrations of indomethacin. In contrast, indomethacin concentration dependently restored the burn-impaired proliferative response, whereas niflumic acid further depressed it and 5-aminosalicylic acid had no effect. These results demonstrate that only some NSAIDs are able to restore T lymphocyte reactivity impaired after thermal injury and that this property is not related to inhibition of PGE2 production. J. Leukoc. Biol. 55: 64–72; 1994.
Functional characterization of interstitial macrophages and subpopulations of alveolar macrophages from rat lung
Authors: Prokhorova Svetlana , Lavnikova Natasha , Laskin Debra L
Published: January 2018

The specific function of interstitial macrophages (IM) in the lung is poorly understood because of difficulties in isolating these cells in high purity or large number. In the present studies, a pure population of en-zymatically isolated IM and lung macrophages obtained mechanically from the lung were compared functionally with alveolar macrophages recovered by lavage (AM). Macrophages isolated mechanically from the tissue and AM displayed similarly high levels of Fc-receptor mediated phagocytosis. In contrast, IM phagocytized significantly fewer opsonized sheep red blood cells per macrophage than AM. In addition, although some variations in the amounts of nitric oxide and superoxide anion produced by AM and macrophages obtained by mechanical tissue disruption were observed, these subpopulations released significantly more of these mediators than IM. These data support the concept that macrophages isolated by mechanical disruption of the tissue represent a subpopulation of AM. We also found that, in contrast to AM, IM did not respond synergistically to combinations of IFN-γ and lipopolysaccharide (LPS) or tumor necrosis factor α in terms of nitric oxide production. Furthermore, regulation of superoxide anion release in AM and IM by LPS and/or IFN-γ was distinct. Taken together, these studies demonstrate that IM are functionally different from other macrophage subpopulations which might reflect their unique location within the lung. J. Leukoc. Biol. 55: 141–146; 1994.
Effects of spaceflight on the number of rat peripheral blood leukocytes and lymphocyte subsets
Authors: Allebban Zuhair , Ichiki Albert T , Gibson Linda A , Jones Jimmy B , Congdon Charles C , Lange Robert D
Published: January 2018

Experiments were carried out on peripheral blood leukocytes and spleen lymphocytes from 29 male rats that were flown during the Spacelab Life Sciences 1 (SLS-1) nine-day mission on the shuttle Columbia in June 1991 and on appropriate ground controls. On the day of landing, there was a significant decrease in the total white blood cell counts (P < 0.0001) of flight animals in comparison to controls. There was also a significant decrease in the absolute number of lymphocytes (P < 0.0001) and monocytes (P < 0.0001) in the flight animals. A slight decrease in the absolute number of eostinophils and a slight increase in the number of neutrophils were observed at landing, compared with preflight values. Immunophenotyping of the peripheral blood and spleen lymphocytes of flight and control animals indicated that, on the day of landing, there was a decrease in the absolute number of CD4 and CD8 positive cells and B lymphocytes. However, relative percentages of peripheral blood CD4 +, CD8 +, and B cells were lot found to be depressed. No differences were discerned in the percent reactivity of spleen lymphocytes of flight animals compared with controls. The observed decrease in the number of leukocytes and lymphocytes at the immediate postflight period was transient and all values returned to the control levels by nine days postflight. J. Leukoc. Biol. 55: 209–213; 1994.
Partial characterization of the proliferative activity for fetal lung epithelial cells produced by silica-exposed alveolar macrophages
Authors: Melloni Boris , Lesur Olivier , Bouhadiba Tayeb , Cantin André , Bégin Raymond
Published: January 2018

The proliferation of lung epithelial cells is a prominent feature of lung tissue response following silica-induced lung injury and alveolar macrophages are recognized as a major contributing cell to the lung inflammatory processes. In previous studies, a growth-promoting activity for fetal rat lung epithelial cells was observed in silicotic alveolar fluids and in supernatants from in vitro and in vivo silica-exposed alveolar macrophages. In the present work, the biological and physicochemical properties of the macrophage-derived growth-promoting activity for fetal lung epithelial cells were explored. Four peaks of growth-promoting activity for lung epithelial cells ranging from 32 to 7 kDa were found in both in vitro and in vivo silica-exposed macrophage supernatants. The investigations were coupled with biochemical treatments of the mitogenic peaks and blocking antibodies or antisera were used to specify further the nature of the proliferative activities. Among the established growth factors, alveolar macrophage–derived growth fractions had characteristics consistent with platelet-derived growth factor–, insulin-like growth factor 1–, and fibroblast growth factor–like molecules. The cytokine production following in vitro exposure, which reflects very early events in the pathogenesis of silicosis, was more strongly related to the high-molecular-weight PDGF-like molecules, whereas the cytokine production following in vivo exposure, which reflects later events in the pathogenesis of silicosis, was more influenced by intermediate-molecular-weight FGF- and IGF-like molecules. J. Leukoc. Biol. 55: 574–580; 1994.
Endotoxin and GM-CSF-mediated down-regulation of macrophage apo E secretion is inhibited by a TNF-specific monoclonal antibody
Authors: Zuckerman Steven H , O’Neal Laura
Published: January 2018

Macrophage activation is associated with increased secretion of monokines, proteases, arachidonic acid metabolites, reactive oxygen, and nitrogen intermediates and yet decreased secretion of apolipoprotein E (apo E). Although the kinetics of apo E down-regulation have been investigated, the mechanism(s) involved remains unknown. In the present study, the question of whether macrophage-activating factors such as lipopolysaccharide (LPS) and granulocyte-macrophage colony-stimulating factor (GM-CSF) directly result in apo E down-regulation or indirectly by inducing the secretion of other inflammatory mediators has been investigated. LPS-stimulated macrophages demonstrated a dose-dependent reduction in apo E secretion with a 70% decrease occurring following a 48-h incubation with 20 ng/ml LPS. Coculture of these cells with a neutralizing concentration of a hamster monoclonal antibody against murine tumor necrosis factor (TNF) inhibited the LPS-mediated reduction in apo E secretion. This inhibitory effect resulting from TNF neutralization was not observed using pooled hamster immunoglobulin G, or hamster monodonals against murine interleukin-lα (IL-lα), IL-1β, or interferon-7. Similar results were observed when GM-CSF was used to induce apo E down-regulation. The inhibitory effects of TNF neutralization on endotoxin-induced apo E down-regulation were dependent on LPS concentration and were no longer apparent at concentrations greater than 200 ng/ml. These results suggest that an autocrine, TNF-dependent mechanism may play a role in the down-regulation of apo E secretion during macrophage activation. J. Leukoc. Biol. 55: 743–748; 1994.
Surface proteins involved in T cell costimulation
Authors: Mondino Anna , Jenkins Marc K
Published: January 2018

The activation and eventual clonal expansion of individual antigen-specific CD4+ T cell clones are dependent on the production of autocrine growth factors such as interleukin-2 (IL-2). The specificity of CD4+ T cell activation is imparted by T cell antigen receptor (TCR) recognition of peptide antigens bound to class II major histocompatibility complex (MHC)-encoded molecules on the surface of antigen-presenting cells (APCs), for example B cells, macrophages, and dendritic cells. To induce maximal IL-2 production by T cells, however, APCs must also provide non-antigen-specific costimulatory signals. Recent work indicates that APC-derived costimulatory signals play a critical role in determining whether lymphokine production, apoptotic cell death, or functional anergy is induced by TCR engagement. This information has allowed immunologists to manipulate costimulatory molecules to prevent allograft rejection and enhance tumor immunity. Here we review current information on the biologic effects of, and signal transduction pathways engaged by, several known receptor-ligand pairs that transduce costimulatory signals in T cells. Special emphasis will be placed on the interaction of CD28 on the T cell with its ligands, B7-1, B7-2, and B7-3 on the APC. J. Leukoc. Biol. 55: 805–815; 1994.
The CD14 differentiation antigen mediates the development of endotoxin responsiveness during differentiation of mononuclear phagocytes
Authors: Martin Thomas R , Mongovin Stephen M , Tobias Peter S , Mathison John C , Moriarty Ann M , Leturcq Didier J , Ulevitch Richard J
Published: January 2018

The CD14 antigen was originally described as a differentiation antigen on mononuclear cells. The purpose of this study was to investigate the relationship between the appearance of surface CD14 and the acquisition of lipopolysaccharide (LPS) responsiveness during maturation of mononuclear phagocytes. Immature THP-1 cells responded poorly to LPS in the absence or presence of serum. Treatment with the maturational agent calcitriol caused a dose- and time-dependent increase in CD14 mRNA and surface CD14 and enhanced the responsiveness of THP-1 cells to smooth and rough form LPS, complexes of LPS and lipopolysaccharide-binding protein (LBP), and LPS in low concentrations of serum. Monoclonal antibodies to CD14 blocked the responses of THP-1 to LPS, LPS-LBP complexes and LPS in serum. Immunodepletion of LBP from serum also inhibited the effect of LPS in serum. The data show that maturation of the response of THP-1 cells to LPS and LPS-LBP complexes depends on the appearance of CD14 on the cell surface. Maturation of the response to LPS in serum depends in large part on the appearance of CD14 on the cell surface and the presence of LBP in serum. J. Leukoc. Biol. 56: 1–9; 1994.
In vivo endotoxin exposure increases neutrophil counts without maintenance of primed superoxide anion release in short-term cultures of sheep bone marrow
Authors: Carey Lisa A , Albertine Kurt H , Gee Marlys H
Published: January 2018

A short-term bone marrow culture was established to determine the functional and proliferative responses of neutrophils sampled from sheep exposed to endotoxin in vivo. Iliac crest bone marrow was drawn from surgical control animals and from sheep given a 12-h infusion of endotoxin. In these bone marrow aspirates, neutrophils from endotoxin-treated sheep showed primed superoxide anion release compared with controls when stimulated with phorbol myristate acetate. Priming was no longer present in neutrophils tested after 2 days in culture. The neutrophil cell count, however, was higher after 2 days in culture than in controls. Increased neutrophil production/viability was reproduced in naive bone marrow cultures by replacing part of the normal serum medium with plasma taken from sheep several hours after endotoxin infusion. These data suggest that a dissociation exists between priming and increased neutrophil production/viability in response to endotoxin. J. Leukoc. Biol. 56: 145–150; 1994.
Dysregulation of cytokine expression in monocytes from HIV-positive individuals
Authors: Lathey Janet L , Kanangat Siva , Rouse Barry T , Agosti Jan M , Spector Stephen A
Published: January 2018

Because HIV may alter the production of inflammatory factors produced by monocytes, the expression of tumor necrosis factor α (TNF-α), tissue factor (TF), interleukin (IL)-1β, and IL-6 was evaluated in 47 HIV-seropositive persons and seronegative control subjects. RNA was extracted from freshly isolated lipopolysaccharide (LPS)-stimulated or unstimulated monocytes. Cytokine and TF expression was quantitated by dot blot hybridization or a reverse transcription polymerase chain reaction (RT-PCR). A significant depression of TF mRNA was observed in LPS-stimulated monocytes (66% less in AIDS, 20% less in AIDS-related complex (ARC), and 0% less in asymptomatic patients), whereas normal responses were observed for TNF-α, IL-1β, and IL-6. When constitutive expression was measured in unstimulated monocytes by RT-PCR, a differential pattern was also observed. TNF-α and IL-1β were positive in 85% of asymptomatic persons, compared with only 27% of ARC and 42% of AIDS patients. Expression of IL-6 was observed in lower proportions, 27-30%, with no significant differences among disease states. All samples were negative for TF. Thus, the regulation of inflammatory molecules is differentially altered in individuals with HIV infection. TF is preferentially down-regulated, compared with TNF-α, IL-1β, and IL-6, in LPS-stimulated monocytes as patients progress to AIDS. TNF-α and IL-1β are preferentially up-regulated, compared with IL-6 and TF, in unstimulated monocytes in asymptomatic persons, with a loss of up-regulation as patients progress to AIDS. J. Leukoc. Biol. 56: 347–352; 1994.
Inhibition of T cell adhesion to extracellular matrix glycoproteins by histamine: a role for mast cell degranulation products
Authors: Hershkoviz Rami , Lider Ofer , Baram Dana , Reshef Tamar , Miron Shmuel , Mekori Yoseph A
Published: January 2018

Mast cells, which are capable of releasing a multitude of preformed and newly generated biological mediators and cytokines, are involved in various inflammatory processes. We studied whether histamine, a mast cell degranulation product, influences the adhesive interactions of T cells with extracellular matrix (ECM) glycoproteins, an event that occurs at sites of inflammation and is mediated primarily by virtue of cell-surface receptors of the β1-integrin subfamily. A prerequisite of lymphocyte-ECM interactions is activation of the cells, which modulates the affinity of the otherwise inactive integrins. Isolated rat CD4+ T cells were preincubated with histamine and activated with phorbol myristate acetate (PMA), and their ability to adhere to immobilized ECM components (fibronectin and laminin) was determined. Preincubation with histamine resulted in a 40–50% decrease in the adhesion of the CD4+ cells to both fibronectin or laminin. The notion that inhibition of T cell adhesion to ECM proteins by histamine-induced increase of the cells’ intracellular levels of cAMP, thus interfering with calcium influx-associated events that occur during T cell activation, is supported by the finding that T cell adhesion was also abrogated by pharmacological inducers of cAMP. When the T cells were preincubated with supernatants of immunologically activated mast cells and then activated with PMA, a 40–50% inhibition of their adhesion to fibronectin or laminin was also observed. The inhibitory moiety present in the mast cell degranulation supernatants was resistant to heat (80°). Histamine exerted its suppressive effect on adhesion of T cells via their H2 receptors, as pretreatment with H2 antagonists abrogated the inhibitory effect. Thus, both purified histamine and mast cell-secreted histamine appear to be capable of affecting T cell interactions with ECM. J. Leukoc. Biol. 56: 495–501; 1994.
Induction of superoxide anion production from monocytes and neutrophils by activated platelets through the P-selectin–sialyl Lewis X interaction
Authors: Tsuji Tsutomu , Nagata Kisaburo , Koike Junzo , Todoroki Naoko , Irimura Tatsuro
Published: January 2018

Activated platelets expressing P-selectin on their surface are known to adhere to monocytes and neutrophils. We examined the possibility that the leukocytes were activated by their adhesion to activated platelets and demonstrated that P-selectin–dependent platelet adhesion to neutrophils and monocytes induced production of extracellular superoxide anion (O2-) by these leukocytes. Leukocyte membrane glycoproteins containing Ser/Thr-linked carbohydrate chains were responsible for the signal reception leading to the leukocyte activation. Cytokines were shown to influence these processes. For example, treatments of neutrophils with interleukin-8 (IL-8) or granulocyte colony-stimulating factor (G-CSF) potentiated the P-selectin-induced O2- production. Furthermore, interleukin-1 (IL-1) and interferon-γ (IFN-γ) induced surface expression of P-selectin on platelets in the presence of a low concentration of thrombin and consequently enhanced their adhesion capacity to leukocytes. These results indicated that the adhesion of activated platelets to the leukocytes through the interaction between P-selectin and its carbohydrate ligand, sialyl Lewis X (Lex), was a crucial step for the activation of leukocyte function and supported the notion that activated platelets were actively involved in the inflammatory processes. J. Lcukoc. Biol. 56: 583–587; 1994.
In vitro and in vivo effects of pentoxifylline on macrophages and lymphocytes derived from autoimmune MRL-lpr/lpr mice
Authors: Hecht Matthias , Müller Meike , Lohmann-Matthes Marie-Luise , Emmendörffer Andreas
Published: January 2018

MRL-lpr/lpr mice develop an autoimmune disease similar to human systemic lupus erythematosus (SLE). The main characteristics of this disease are increasing autoantibody formation, elevated plasma levels of immune complexes, a massive lymphoproliferation, a rising proteinuria, and arthritic symptoms. Finally, the mice die at an age of about 6 months due to a fatal immune complex glomerulonephritis. Macrophages are involved in the development of SLE due to their functions as antigen-presenting as well as cytokine-producing cells. T and B cells are involved in the disease by secreting cytokines and producing antibodies. Pentoxifylline (PTX), a xanthine derivative, is known to exert different effects on functions of leukocytes and erythrocytes and has been used in clinical studies, e.g., in septic shock syndrome. In our studies we first investigated the in vitro effect of PTX on macrophages and lymphocytes derived from MRL-lpr mice. Our investigations concerning production of superoxide anion and TNF-α by LPS and/or IFN-γ activated bone marrow and peritoneal macrophages, MHC class II expression on these cells, and the proliferative capacity and Il-2 production of mitogen activated lymphocytes, revealed that PTX reduces the activation and the inflammatory response of these cells. Based on these results, we further investigated the effect of in vivo treatment with PTX. MRL-lpr mice treated with PTX showed diminished proteinuria, reduced titer of dsDNA-autoantibodies in the plasma and an increased survival rate. Our data clearly demonstrate that PTX is able to diminish the severity of the disease and to prolong the life of MRL-lpr/lpr mice. J. Leukoc. Biol. 57: 242–249; 1995.
Free-form neutrophil elastase is an independent marker predicting recurrence in primary breast cancer
Authors: Yamashita Jun-ichi , Ogawa Michio , Shirakusa Takayuki
Published: January 2018

We have measured the immunoreactive neutrophil elastase (ir-NE) concentration in tumor extracts of 313 primary human breast cancers using an enzyme-linked immunosorbent assay recently developed and have evaluated its association with disease-free survival. This is a sensitive assay that enables rapid measurement of both free-form and α1-proteinase inhibitor (α1-PI)–complexed form of ir-NE. Breast cancer patients with high ir-NE concentrations had a significantly shorter disease-free survival (P = .013) than those with a low ir-NE concentration at the cutoff point of 9.0 μg/100 mg protein, which was determined in another group of 49 patients. In multivariate analysis, the ir-NE level was found to be an independent prognostic factor (relative risk = 2.2, P = .025) for disease recurrence in human breast cancer. Furthermore, when multivariate analysis was repeated with inclusion of each level of free-form and α1-PI-complexed form, the former level was an independent predictor of recurrence (relative risk = 2.5, P = .015), whereas the latter was not independently predictive (P = .43). These results support the hypothesis that this enzyme may play an active role in the tumor progression that leads to metastasis in human breast cancer. J. Leukoc. Biol. 57: 375–378; 1995.
C1q triggers neutrophil superoxide production by a unique CD18-dependent mechanism
Authors: Goodman Elaine B , Anderson Donald C , Tenner Andrea J
Published: January 2018

Complement protein C1q induces the production of superoxide (O2-) by neutrophils via an as yet unidentified receptor or receptor complex. Several strategies were therefore used to identify cell surface molecules involved in the response of neutrophils to C1q and its collagen-like domain (C1q-CLR). Treatment of neutrophils with phosphatidylinositol-specific phospholipase C effectively removed the phosphatidylinositol-linked surface molecules CD14 and CD16, yet did not reduce Of production in response to C1q. Next, 17 monoclonal antibodies (mAbs) recognizing various neutrophil surface antigens were tested for their ability to inhibit C1q-CLR-mediated O2- production. Only two of the mAbs, 44a and IB4, which recognize CD11b/CD18 (complement receptor 3 or Mac-1), were inhibitory. In addition, neutrophils from a patient with leukocyte adhesion deficiency, which are CD18 deficient, did not produce Of in response to C1q or C1q-CLR. Because CD11b/CD18 is recognized to play a role in cell adhesion, the role of adherence in C1q-mediated O2- production was explored. Adherence of neutrophils to C1q-CLR-coated surfaces occurred with kinetics, which usually paralleled those of O2- production, and was invariably abolished by the anti-CD11b mAb 44a. However, this mAb often only partially inhibited O2- production, indicating that an avid attachment of neutrophils to the C1q-CLR-coated surface is not required for O2- production. J. Leukoc. Biol. 58: 168–176; 1995.
Alveolar macrophages as a cell source of cytokine hyperproduction in HIV-related interstitial lung disease
Authors: Agostini Carlo , Sancetta Rosaria , Cerutti Andrea , Semenzato Gianpietro
Published: January 2018

Pulmonary macrophages play an important role in the pathogenesis of the acquired immunodeficiency syndrome (AIDS). They are known to be discrete target cells for human immunodeficiency virus (HIV), and compelling evidence is accumulating that alveolar macrophages (AMs) from HIV-infected patients behave as versatile secretory cells that, acting as antigen-presenting cells, release a great variety of cytokines. The secretory products of AMs, pivotal to their immune effects, may contribute to localized immune dysregulation as well as to primary lung damage and clinical disease. Pulmonary macrophages are also thought to facilitate retroviral spread by their direct infection, by presenting HIV antigens to uninfected T cells, and by secreting cytokines that trans-activate HIV expression. This review briefly considers the events underlying the role of AMs in the pulmonary defense mechanisms against HIV and AIDS-related opportunistic infections. Following a brief overview of immune mechanisms taking place in the lungs of HIV-infected subjects, we describe the specific role of AMs in the immune mechanisms devoted to recognizing and removing HIV-infected cells and controlling the local growth of opportunists. The pathogenetic role envisaged for macrophages in lung damage are also reviewed in the context of the known biology of these cells. Finally, this review examines the relevance of the retroviral infection of AMs in terms of pathogenesis of the HIV-related interstitial lung disease.
Temporal sequence of pulmonary cytokine gene expression in response to endotoxin in C3H/HeN endotoxin-sensitive and C3H/HeJ endotoxin-resistant mice
Authors: Nill Michael R , Oberyszyn Tatiana M , Ross Mary S , Oberyszyn Andrew S , Robertson Fredika M
Published: January 2018

Although previous studies suggested that tumor necrosis factor alpha (TNF-α) was a critical cytokine responsible for the inflammation observed after exposure to endotoxin, other mediators may also play an important role in the regulation of systemic inflammatory responses independent of TNF-α. The present study compared the temporal sequence of endotoxin-induced TNF-α, interleukin-1α (IL-1α), and interleukin-10 (IL-10) gene expression and cellular localization of cytokine proteins in pulmonary tissue of two strains of mice that have a genetically based differential sensitivity to endotoxin. Lung tissue and plasma were harvested from endotoxin-sensitive C3H/HeN and endotoxin-resistant C3H/HeJ micé at 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after intraperitoneal (i.p.) injection of 5 mg/kg endotoxin (Escherichia coli–derived lipopolysaccharide, serotype 0111:B4). There were significant elevations in both TNF-α gene and IL-2α expression immediately (15 min) after endotoxin injection in C3H/HeN mice. Although levels of TNF-α mRNA in the two mouse strains were similar at 1-2 h, the IL-1α gene expression in pulmonary tissue isolated from endotoxin-resistant mice was not comparable to the levels detected in C3H/HeN endotoxin-sensitive mice at the same times. The most dramatic difference in endotoxin-induced cytokine gene expression between the two strains of mice was in IL-10 mRNA levels in pulmonary tissue isolated from endotoxin-sensitive mice, compared to the lack of detectable increase in IL-10 gene expression in C3H/HeJ endotoxin-resistant mice above baseline at any time point examined. Quantitation of neutrophil infiltration into pulmonary tissue using immunochemical detection of CR-1, a myeloid differentiation-specific antibody, demonstrated that there was a significantly decreased inflammatory infiltrate in pulmonary tissue isolated from C3H/HeJ mice following endotoxin administration, which correlated with decreased levels of proinflammatory cytokine immunoreactive protein within pulmonary cells. Pulmonary cytokine synthesis and immunoreactive protein production did not directly correlate with either the magnitude or the temporal sequence of increases in plasma cytokine levels, suggesting that systemic levels of cytokines may not accurately reflect the cytokine response within the local tissue milieu. The present observations demonstrate that the differential synthesis and production of immunosuppressive cytokines as well as proinflammatory cytokines may be important variables in the determination of the extent of infiltration of inflammatory cells into the local pulmonary site in response to endotoxin and may significantly contribute to the determination of sensitivity or resistance to endotoxin in this murine model.
Macrophage apoptosis in the absence of active interleukin-1β-converting enzyme
Authors: Nett-Fiordalisi Michelle , Tomaselli Kevin , Russell John H , Chaplin David D
Published: January 2018

The interleukin-1β converting enzyme (ICE) is the cysteine proteinase responsible for cleaving the 31-kDa interleukin-1β (IL-1β) precursor to its active 17-kDa form. In lipopolysaccharide-stimulated cultured macrophages, induction of apoptosis but not necrosis effectively induces conversion of the IL-1β precursor to its mature form and results in the concomitant release of the mature cytokine from the cell. To determine whether ICE activity is required for macrophage apoptosis, we have exposed macrophages either to 5 mM ATP or to alloreactive cytolytic T lymphocytes (CTL) in the absence and presence of the ICE inhibitor peptide YVAD-chloromethylketone (YVAD-cmk). Activated cells treated with YVAD-cmk and ATP or CTL showed no mature IL-1β in either the cell lysates or the culture supernatants, indicating effective inhibition of ICE activity; however, the YVAD-treated macrophages showed no detectable change in 51Cr release or nuclear fragmentation, indicating failure to inhibit apoptotic cell death. Thus, in these cells, YVAD-cmk uncouples IL-1β processing and apoptosis.
Activation and regulation of chemokines in allergic airway inflammation
Authors: Lukacs N W , Strieter R M , Chensue S W , Kunkel S L
Published: January 2018

Allergic airway inflammation is characterized by peribronchial eosinophil accumulation within the submucosa surrounding the airway. The initial induction of immunoglobulin E (IgE)-mediated mast cell degranulation, up-regulation of adhesion molecules, and the production of inflammatory and chemotactic cytokines, leading to the infiltration of specific leukocyte subsets, is orchestrated in a sequential manner. The activation and degranulation of local mast cell populations is an immediate airway response mediated both by antigen-specific, surface bound IgE and by cytokine-induced activational pathways. Subsequently the infiltration and activation of effector leukocytes (neutrophils and eosinophils) mediated by the persistant activation of allergen-specific T cells leads to pathological manifestations within the lung and airway. The development of appropriate animal models to dissect the critical mechanisms involved in antigen-induced airway pathology is crucial for the development of efficacious therapies. We have utilized a model of allergic airway inflammation induced by intratracheal challenge with parasite (Schistosoma mansoni) egg antigen in presensitized mice. This model has proven useful in the assessment of eosinophil recruitment and has identified key cytokines involved in leukocyte elicitation. These cytokines include interleukin-4 and tumor necrosis factor, which appear to act as early response mediators, as well as C-C chemokines, macrophage inflammatory protein-1a, and RANTES, which act directly on eosinophil recruitment. In addition, we have found that both C-X-C and C-C chemokines are expressed in pulmonary-derived mast cells, suggesting an important contribution to leukocyte responses in the allergic airway.
Human CD14+ leukocytes acquire the phenotype and function of antigen-presenting dendritic cells when cultured in GM-CSF and IL-4
Authors: Kiertscher Sylvia M , Roth Michael D
Published: January 2018

The combination of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) induces the growth of antigen-presenting cells (APC) from adherent peripheral blood leukocytes. These cells have been characterized as dendritic cells (DC), yet many questions exist regarding their relationship to other DC populations and the nature of their progenitors. To address these issues, we utilized a combination of immunomagnetic depletion, cell sorting, and cell culture to isolate four distinct APC populations; macrophages expressing high levels of CD14 (CD14bright macrophages), DC produced by culturing adherent cells in GM-CSF and IL-4 (cultured DC), and two different subsets of fresh DC that express low levels of CD14 (CD14dim DC). Each population exhibited a unique morphology and a unique profile of cell surface markers. In contrast to macrophages, all three DC populations expressed the DC marker CD83, as well as high levels of MHC molecules and the costimulatory molecules B7-1 (CD80) and B7-2 (CD86). In addition, all three DC populations presented soluble tetanus toxin antigen and stimulated T cell proliferation to levels far superior to that of macrophages. Blocking studies demonstrated a costimulatory role for B7-1, B7-2, and CD40 in antigen presentation, although B7-2 expression was the single most important factor. To identify the progenitors of cultured DC, we sorted the adherent fraction of PBMC into discrete subpopulations prior to exposure to GM-CSF and IL-4. DC activity derived entirely from CD14+ precursors and was equally demonstrable using either the CD14dim or CD14bright subsets. Although these DC precursors lost expression of CD14 in culture, they maintained most of their other myeloid features. We conclude that human CD14+ leukocytes acquire the phenotype and function of DC when cultured in GM-CSF and IL-4.
Accounting for the peripartum loss of granulated metrial gland cells, a natural killer cell population, from the pregnant mouse uterus
Authors: Delgado Silvia R , McBey Betty-Anne , Yamashiro Shigeto , Fujita Jun , Kiso Yasuo , Croy B Anne
Published: January 2018

Natural killer (NK) cells become a prominent cell population in the rodent uterus during pregnancy. The mature, heavily granulated form of these cells is rare in virgin or postpartum uteri. Death, migration, or dedifferentiation could account for the disappearance of these cells from late gestation uteri. We asked whether uterine NK cells, also known as granulated metrial gland (GMG) cells, die in situ and if expression of Fas antigen is essential for their death. Late in gestation, fragmentation of nuclear DNA was detected histologically by OH-end labeling, as were ultrastructural changes suggesting cell death. NK cells developed in and were lost from the uteri of pregnant Fas antigen-deficient lpr/lpr mice. Postpartum samples of retained placentas contained some residual NK cells that had moved from regions of uterine musculature toward the uterine lumen and were being expelled with the placenta. Thus, both cell death and placental separation remove NK cells from the peripartum uterus.
Activation of alveolar macrophage TNF and MCP-1 expression in vivo by a synthetic peptide of C-reactive protein
Authors: Barna Barbara P , Thomassen Mary Jane , Zhou Ping , Pettay James , Singh-Burgess Sugatha , Deodhar Sharad D
Published: January 2018

Administration of multilamellar vesicles (MLV) encapsulating a synthetic peptide (RS-83277) derived from human C-reactive protein (CRP) augments anti-tumor activity of murine alveolar macrophages and reduces established pulmonary metastases of experimental tumors. To explore mechanisms involved in these phenomena, we investigated cytokine and integrin (CD11b) expression of bronchoalveolar lavage (BAL)-derived alveolar macrophages in control (blank MLV) and RS-83277-MLV-treated C57B1 mice. Alveolar macrophage production of tumor necrosis factor α (TNF-α) and monocyte chemoattractant bioactivity increased at 48 h after treatment with RS-83277-MLV but not control MLV. Chemoattractant activity was neutralized by antibody to monocyte chemoattractant protein-1 (MCP-1), but not irrelevant immunoglobulin G (IgG). Changes were reflected by augmented TNF-α and MCP-1 mRNA levels in pulmonary tissue and enhanced CD11b expression on mononuclear leukocytes derived from total lung tissue, but not on BAL-derived alveolar macrophages. Results suggest that RS-83277-MLV treatment is associated with activation of alveolar macrophage TNF-α and MCP-1 production and up-regulation of adhesion molecules on pulmonary mononuclear leukocytes but not on alveolar macrophages.
Regulation of cytokine gene expression by reactive oxygen and reactive nitrogen intermediates
Authors: Remick Daniel G , Villarete Lorelie
Published: January 2018

Reactive oxygen intermediates (ROI), reactive nitrogen intermediates (RNI), and cytokines are frequent companions at sites of acute inflammation. Previous work has established a clear link between the production of cytokines and the subsequent generation of ROI and RNI. However, more recent data indicates that ROI and RNI not only serve as end-stage effector molecules of pathogen destruction and tissue injury, but also as initiators of acute inflammation. Specifically, ROI and RNI will up-regulate cytokine gene expression since antioxidants inhibit interleukin 8 (IL-8) production and do not decrease production of other cytokines. Treatment with hydroxyl radical scavengers such as dimethyl sulfoxide (DMSO) will decrease the production of IL-8 in stimulated human whole blood, fibroblasts, type II epithelial cells, and hepatoma cells, but not other cytokines. Addition of exogenous ROI will increase IL-8 production in these same cells. Inhibition of nitric oxide synthase will decrease production of IL-8, whereas addition of nitric oxide (NO)-generating compounds will increase production of IL-8. The hydroxyl radical appears to be the final common pathway of cell activation for IL-8 synthesis, since DMSO will inhibit the NO-driven production of IL-8. Our data indicate that ROI and RNI can serve as intracellular second messengers to induce IL-8 gene expression.
Transcriptional basis for hyporesponsiveness of the human inducible nitric oxide synthase gene to lipopolysaccharide/interferon-γ
Authors: Zhang Xiaoke , Laubach Victor E , Alley Evan W , Edwards Kevin A , Sherman Paula A , Russell Stephen W , Murphy William J
Published: January 2018

The work reported here resolves, at the level of gene regulation, the controversy as to whether or not human monocytes/macrophages can produce nitric oxide (NO) when stimulated with lipopolysaccharide (LPS), with or without co-stimulation by interferon-γ(IFN-γ). Studies included structural comparison of the promoters for human and mouse inducible NO synthase (iNOS) genes, transfection and assay of human and mouse iNOS promoter regions in response to LPS ± IFN-γ, and electrophoretic mobility shift assays of KB response elements. Two explanations for hyporesponsiveness of the human iNOS promoter to LPS ± IFN-γ were found: (1) multiple inactivating nucleotide substitutions in the human counterpart of the enhancer element that has been shown to regulate LPS/IFN-γ-induced expression of the mouse iNOS gene; and (2) an absence of one or more nuclear factors in human macrophages (e.g., an LPS-inducible nuclear factor-κB/Rel complex), that is (are) required for maximal expression of the gene. The importance of resolution of this controversy is that future research in this area should be directed toward the understanding of alternative mechanisms that can result in the successful production of NO.
Bradykinin stimulates phosphoinositide turnover and phospholipase C but not phospholipase D and NADPH oxidase in human neutrophils
Authors: Catz Sergio D , Sterín-Speziale Norma B
Published: January 2018

In response to formyl-Met-Leu-Phe (fMLP), human neutrophils (PMN) generate superoxide anion (O2-) by the enzyme complex NADPH oxidase. The modulation of phosphoinositide (PPI) turnover and the activation of phospholipases C (PLC) and D (PLD) have been shown to be early steps in the oxidative response of fMLP-stimulated PMN. Although the physiological nonapeptide bradykinin (BK) is involved in inflammation, its participation in PMN activation has not been properly studied. In this work, activation of signal transduction pathways that mediate the oxidative response, and the modulation of the NADPH oxidase activity by BK, are analyzed. A direct comparison between the signal transduction pathway induced by BK and fMLP is also made. BK was not able to elicit O2- production by PMN. Nevertheless, several signal transduction pathways associated with PMN activation were triggered by BK. The nonapeptide induced the phosphorylation of prelabeled membrane PPI. This phenomenon was imitated by PMA and inhibited by H7 and staurosporine, thus suggesting the participation of protein kinase c (PKC). A loss of labeled [32P]PPI was triggered by fMLP. The fact that both PMA and fMLP stimulated O2- production but modulated PPI turnover in different ways, indicates that PPI labeling does not correlate with the oxidative response. Because PKC activation seemed to be a prerequisite for BK-induced modulation of PPI turnover, PLC activation could act as an intermediate step in this mechanism. Our results show that BK activated a PIP2-PLC measured as the release of [3H]IP3. On the contrary, a PC-PLD was highly stimulated by fMLP but not by BK. The fact that BK induced PLC activity but neither that of PLD nor NADPH oxidase, whereas fMLP triggered the activation of both phospholipases and evoked the PMN respiratory burst, suggests that diacylglycerol (DAG) from PIP2 as well as PA or PA-derived DAG, synergize to trigger the PMN oxidative response. Finally, BK inhibited O2-production by fMLP-activated PMN in a time-dependent manner. Since BK did not induce NO production by PMN, the inhibitory effect on the oxidative function was not due to ONOO- formation. These data show that BK plays an important role in inflammation by modulating the PMN function.
IL-13 restores an in vitro specific cytolytic response of spleen cells from tumor-bearing rats
Authors: Reisser Danièle , Pinard Dominique , Jeannin Jean-François
Published: January 2018

In a model of colon cancer, spleen cells from tumor-bearing rats are neither cytotoxic nor proliferative in vitro in the presence of tumor cells. Interleukin-13 (IL-13) induced an in vitro cytolytic activity of spleen cells from tumor-bearing rats in response to the tumor they bore, but had no effect on spleen cells from normal rats. This cytotoxic response was dependent on both adherent and nonadherent cells, involving both an antigen-presenting activity that was enhanced by IL-13 and a cytolytic activity of lymphocytes. So, IL-13 reversed the tumor-induced immunosuppression.
Inhibition of neutrophil-endothelial cell adhesion by a neutrophil product, cathepsin G
Authors: Renesto Patricia , Halbwachs-Mecarelli Lise , Bessou Gilles , Balloy V , Chignard Michel
Published: January 2018

In the present study we investigated the modulation of the polymorphonuclear neutrophil (PMN)-endothelial cell adhesion process by the two main proteinases released from activated PMN during their adhesion to endothelium. Our results showed that, in contrast with elastase, cathepsin G was a powerful inhibitor of PMN adhesion to interleukin-1 (IL-1)-treated human umbilical vein endothelial cells. This inhibitory effect was linked to the enzymatic activity of the proteinase and was selectively directed against PMN. Because the viability and the reactivity of PMN were not modified by cathepsin G, we looked for a possible effect on adhesion molecules. L-selectin was not cleaved by cathepsin G, whereas it was by chymotrypsin, a closely related proteinase. Cathepsin G blocked PMN adhesion to activated endothelial cells, but also to serum- or fibrinogen-coated plates, three adhesion processes mediated by GD11b/CD18. However, by FACScan analysis or by immunoprecipitation, we failed to find evidence of modifications of CD11b/CD18 expression. Although the precise molecular target(s) of cathepsin G remain(s) to be defined, these data indicate that this proteinase, which is known as an inflammatory mediator, can also be considered as a potential down-regulator of adhesion reactions involved in the inflammatory process.
Induction of homotypic lymphocyte aggregation: evidence for a novel activation state of the β1 integrin
Authors: Neelamegham Sriram , Simon Scott I , McIntyre Bradley W , Zygourakis Kyriacos
Published: January 2018

Intercellular adhesion of Jurkat lymphocytic cells was investigated by use of monoclonal antibodies 33B6 and 18D3, which bind to the β1 integrin receptor. 33B6 induced homotypic aggregation of Jurkat cells, whereas 18D3 inhibited this aggregation. Jurkat cells could be induced to aggregate at low 33B6 concentrations corresponding to 5% β1 integrin site occupancy, and the rate of aggregation was maximum at 30% occupancy. Simultaneous addition of mAb 18D3 and 33B6 demonstrated that the two antibodies mediate changes in the β1 integrin activation state that are competitive in nature. Aggregation through β1 integrin induced by 33B6 was reversed by subsequent addition of 18D3. To further examine the mechanism by which 33B6 and 18D3 affect cell adhesion function, we explored the binding of monoclonal antibody (mAb) 15/7. This mAb recognizes an activation epitope of the β1 integrin and has been shown to sustain cell adhesion to vascular cell adhesion molecule 1 (VCAM-1) and fibronectin. Activation of Jurkat cells with Mn2+ caused a 2.5-fold increase in 15/7 binding but did not increase binding of 33B6. 33B6 partially blocked 15/7 binding to β1 integrin on unstimulated and Mn2+-activated Jurkat cells. 18D3 did not affect mAb 15/7 binding. These results indicate that 33B6 and 18D3 modulated homotypic aggregation by inducing a novel activation state of the very late activation integrin distinct from the state recognized by 15/7, which supports cell binding to VCAM-1 and fibronectin.
Altered monocyte chemotactic and activating factor gene expression in human glioblastoma cell lines increased their susceptibility to cytotoxicity
Authors: Asano Takeshi , An Taeha , Jia Shu-Fang , Kleinerman Eugenie S
Published: January 2018

A cDNA encoding for human monocyte chemotactic and activating factor (MCAF) was ligated into the retroviral vector pLXSN. These pMCAF-LXSN and antisense p-antiMCAF-LXSN vectors were transfected into HBT20 and HBT28 human brain tumor cells. HBT28 cells constitutively express high amounts of MCAF, whereas HBT20 cells express much less MCAF. HBT20 cells transfected with pMCAF-LXSN (HBT20-MCAF) showed significantly higher MCAF mRNA expression and MCAF protein production than the HBT20-parent or HBT20 cells transfected with control vector (HBT20-LXSN). In contrast, supernatant from HBT28 cells transfected with p-antiMCAF-LXSN (HBT28-antiMCAF) contained less MCAF than HBT28-parent, HBT28-LXSN, and HBT28-MCAF cells. Activated human monocytes killed HBT20-MCAF cells more efficiently compared with HBT20-parent, HBT20-LXSN, and HBT20-antiMCAF cells (P< 0.02), whereas HBT28-antiMCAF cells were killed more efficiently by activated monocytes compared with HBT28-parent, HBT28-LXSN, and HBT28-MCAF cells (P< 0.05). Cultured supernatants from activated monocytes plus HBT20-MCAF cells or from activated monocytes plus HBT28-antiMCAF cells inhibited the growth of HBT20 and HBT28 cells, respectively. Altered MCAF expression can therefore enhance the ability of activated monocytes to kill brain tumor cells. This increased cytotoxicity is partially dependent upon the basal state of MCAF in the individual tumor cells.