bluuebunny/crossref_metadata_2025 huggingface dataset:
Profile of human macrophage transcripts: insights into macrophage biology and identification of novel chemokines
Authors: Chantry David , DeMaggio Anthony J , Brammer Heather , Raport Carol J , Wood Christi L , Schweickart Vicki L , Epp Angela , Smith Aaron , Stine Johnny T , Walton Kim , Tjoelker Larry , Godiska Ronald , Gray Patrick W
Published: January 2018

High throughput partial sequencing of randomly selected cDNA clones has proven to be a powerful tool for examining the relative abundance of mRNAs and for the identification of novel gene products. Because of the important role played by macrophages in immune and inflammatory responses, we sequenced over 3000 randomly selected cDNA clones from a human macrophage library. These sequences represent a molecular inventory of mRNAs from macrophages and provide a catalog of highly expressed transcripts. Two of the most abundant clones encode recently identified CC chemokines. Macrophage-derived chemokine (MDC) plays a complex role in immunoregulation and is a potent chemoattractant for dendritic cells, T cells, and natural killer cells. The chemokine receptor CCR4 binds MDC with high affinity and also responds by calcium flux and chemotaxis. CCR4 has been shown to be expressed by Th2 type T cells. Recent studies also implicate MDC as a major component of the host defense against human immunodeficiency virus. J. Leukoc. Biol. 64: 49–54; 1998.
Ex vivo expansion of hematopoietic cells from umbilical cord blood for clinical transplantation
Authors: Conrad Patricia D , Emerson Stephen G
Published: January 2018

Stem cell transplantation (SCT) has achieved significant therapeutic success over the last 10 years, providing a viable treatment option for many previously incurable diseases. However, several inherent limitations of the procedure have restricted its widespread use. These include: lack of sufficient donors for all recipients, a period of bone marrow (BM) aplasia leading to severe, prolonged neutropenia and thrombocytopenia, and the potential for tumor contamination in autologous SCT. Umbilical cord blood (UCB) provides a unique, and potentially more successful, approach to alleviating these limitations. Ex vivo manipulation of hematopoietic stem (HSCs) and progenitor cells (HPCs) derived from UCB using a liquid culture system has revealed that the primitive HSCs from UCB are not identical to their BM counterparts. In fact, these cells may derive from a more primitive stem cell compartment. Ultimately, successful engraftment of UCB HSCs manipulated in an ex vivo environment may lead to a larger number of these life-saving procedures being performed and the full potential of SCT realized. J. Leukoc. Biol. 64: 147–155; 1998.
Gangliosides of monocyte-derived macrophages of adults with advanced HIV infection show reduced surface accessibility
Authors: Berenson Charles S , Gallery Melissa A , Katari Manpreet S , Foster Edward W , Pattoli Mark A
Published: January 2018

Gangliosides of macrophages are potent immunoregulatory molecules. A monoclonal antibody directed at human macrophage gangliosides (25F4) inhibits macrophage migration with relative specificity. Recent reports suggested that greater expression of Gm1 in mononuclear cells accompanies advanced HIV infection, although others failed to demonstrate any differences in vitro. We purified gangliosides from blood monocyte-derived macrophages obtained from HIV-infected adults. Densitometric analysis of chromatograms demonstrated no differences in relative quantities of any macrophage gangliosides among all HIV-positive and -negative donors. Antibody 25F4 showed equivalent ELISA reactivity with purified macrophage gangliosides of HIV-positive and -negative donors. However, intact macrophages of HIV donors with CD4+ cell counts <200/mm3 showed impaired immunofluorescent surface expression of the 25F4 epitope and concomitant loss of migration inhibitory responsiveness. Thus, although relative content is unchanged, macrophage gangliosides become surface-inaccessible in adults with advanced HIV infection. Our data provide further evidence that dysregulation of glycosphingolipid metabolism in HIV-1 infection contributes to immune dysfunction. J. Leukoc. Biol. 64: 311–321; 1998.
Fas ligand (gld)- and Fas (lpr)-deficient mice do not show alterations in the extravasation or apoptosis of inflammatory neutrophils
Authors: Fecho Karamarie , Cohen Philip L
Published: January 2018

Apoptosis of neutrophils plays a critical role in the resolution of acute inflammation. Neutrophils from human peripheral blood express Fas (CD95) and are sensitive to Fas ligand (FasL)/Fas-mediated apoptosis. Mice carrying spontaneous mutations in the genes for fas ligand (B6/gld) or fas (B6/lpr) were used to assess the role of FasL/Fas in the kinetics and magnitude of neutrophil extravasation to the thioglycolate (TG)-inflamed peritoneum and in the spontaneous apoptosis of TG-elicited neutrophils. The results showed that TG-elicited neutrophils (defined by flow cytometry as GR-1/Ly-6Ghi cells) from normal (B6) and B6/gld mice, but not from the Fas-deficient B6/lpr mice, express high levels of Fas. The TG-elicited neutrophil response began at 2 h, peaked at 4 h, and subsided by 24–48 h after TG administration in all three strains. However, the response was more prolonged in B6 mice, such that B6/gld and B6/lpr mice had fewer neutrophils at 6 h after TG administration than did B6 mice. Further studies showed that 4 h TG-elicited neutrophils from B6, B6/gld and B6/lpr mice undergo apoptosis in vitro at similar rates (as assessed through flow cytometry by the decrease in forward angle light-scatter and externalization of phosphatidylserine (PS; as detected by Annexin V-FITC) that occur as neutrophils undergo apoptosis). Fas expression was down-regulated on apoptotic neutrophils in conjunction with maximal PS externalization and decreased forward angle light-scatter. Collectively, these findings suggest that FasL/Fas-mediated apoptosis is not essential in regulating the lifespan of neutrophils during an acute inflammatory response. The abbreviated inflammatory response observed in FasL/Fas-deficient mice is likely to be a secondary effect of the gld/lpr autoimmune/lymphoproliferative syndrome, and not a direct effect of FasL/Fas on the ability of inflammatory neutrophils to undergo apoptosis. J. Leukoc. Biol. 64: 373–383; 1998.
Nitric oxide enhances the growth of U937 human leukemic cells through a cyclooxygenase-mediated pathway
Authors: Jea Jing-Chi , Liu Tsuei-Chu , Wang Sheng-Yuan , Sung Yen-Jen
Published: January 2018

The mechanisms of exogenous nitric oxide (NO)-enhanced growth of the U937 human myeloid leukemic cells were examined using sodium nitroprusside (SNP) as a NO donor. Treatment with 0.1 mM SNP for 72 h caused a 45 ± 2% increase in U937 cell growth with significantly increased S/G2 + M-phase and decreased G0/G1-phase of the cell cycle. The growth-enhancing effect of SNP was blocked by indomethacin, a cyclooxygenase inhibitor, but not by H7, a broad spectrum kinase inhibitor, or PD98059, a mitogen-activated protein kinase inhibitor. SNP treatment resulted in a dose-dependent increase in prostaglandin E2 (PGE2) production. Furthermore, the addition of exogenous PGE2 not only enhanced U937 cell growth but restored the indomethacin-inhibited mitogenic effect of SNP. We suggest that NO can enhance cell growth through activating the cyclooxygenase pathway and that PGE2 may be an effector molecule for NO-regulated cell proliferation. Our data provide a mechanistic insight into the regulatory role of NO in myelopoiesis. J. Leukoc. Biol. 64: 451–458; 1998.
Strong expression of CD134 (OX40), a member of the TNF receptor family, in a T helper 2-type cytokine environment
Authors: Roos Anja , Schilder-Tol Esther J M , Weening Jan J , Aten Jan
Published: January 2018

CD134 (OX40) is involved in T cell costimulation and T cell-dependent antibody production. We show strongly increased T cell expression of CD134 in a model of T helper 2-mediated systemic autoimmunity, induced by HgCl2. Regulation of CD134 expression on CD4+ T cells was further studied in vitro, identifying CD134 as an early marker of T cell activation. CD134 expression could be induced by interleukin-4, but not by interferon-γ or tumor necrosis factor-α. Effects of interleukin-4 and of phorbol 12-myristate 13-acetate on CD134 expression could be blocked by the protein kinase inhibitor staurosporin. Combination of these stimuli with ionomycin resulted in a strongly synergistic increase of CD134 expression, which was blocked by the calcineurin-inhibitor cyclosporin A. The results demonstrate the involvement of two synergistically acting pathways in induction of CD134 expression. Furthermore, they suggest a role for interleukin-4 in induction of CD134 expression in vivo. J. Leukoc. Biol. 64: 503–510; 1998.
Pathways for eosinophil lipid body induction: differing signal transduction in cells from normal and hypereosinophilic subjects
Authors: Bozza Patricia T , Yu Wengui , Cassara Jessica , Weller Peter F
Published: January 2018

Although lipid bodies, inducible cytoplasmic inclusions active in arachidonic acid metabolism, are abundant in activated leukocytes, including eosinophils, mechanisms for eosinophil lipid body formation are not certain. Eosinophils from hypereosinophilic syndrome (HES) donors contained about twice (~18/cell) as many lipid bodies as eosinophils from normal donors (~10/cell). By immunocytochemistry both 5- and 15-lipoxygenases were localized at lipid bodies in HES eosinophils. Platelet-activating factor (PAF) induced rapid, receptor-mediated increases in lipid bodies in normal and HES eosinophils. Protein kinase C (PKC) inhibitors, chelerythrine and calphostin C, inhibited PAF-induced lipid body formation partially in normal and HES eosinophils. In HES, but not normal, eosinophils, PAF-induced lipid body formation was completely blocked by two tyrosine kinase inhibitors, herbimycin A and genistein, which were not acting on 5-lipoxygenase because they also blocked 5-HETE-induced lipid body formation in HES, and not normal, eosinophils. After 24 h culture with eosinophil growth factor cytokines [interleukin (IL)-3, IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF) or GM-CSF alone but not IL-5 or IL-3 alone], normal eosinophils were induced to exhibit an HES-like phenotype, including increased lipid body numbers and tyrosine kinase-dependent signaling for PAF-induced lipid body formation. Thus, signal transduction mechanisms involved in PAF-induced lipid body formation in eosinophils can be differentially recruited. Tyrosine kinase-dependent signaling is not involved in normal eosinophils, but is active in HES eosinophils and in normal eosinophils cultured with GM-CSF. PKC- and tyrosine kinase-dependent pathways are involved in the formation of eosinophil lipid bodies, which may facilitate enhanced synthesis of lipoxygenase-derived eicosanoids. J. Leukoc. Biol. 64: 563–569; 1998.
Regulation of macrophage phagocytosis of apoptotic neutrophils by adhesion to fibronectin.
Authors: McCutcheon Judith C , Hart Simon P , Canning Mary , Ross Katherine , Humphries Martin J , Dransfield Ian
Published: January 2018

The potential for leukocyte-mediated host tissue damage during resolution of inflammatory responses is influenced by the rate at which extravasated apoptotic leukocytes are cleared from inflammatory sites. Regulation of macrophage capacity for clearance of apoptotic granulocytes is likely to be an important factor determining whether inflammation ultimately resolves or progresses to a chronic state. In this study we have investigated the molecular basis for rapid augmentation of macrophage phagocytosis of apoptotic neutrophils, which was observed following macrophage adhesion to fibronectin. We used a combination of monoclonal antibodies, blocking peptides, and recombinant fibronectin fragments to investigate the role of β1 integrins in mediating the fibronectin effects. Blockade of α5β1 or α4β1 alone did not attenuate fibronectin-augmentation of phagocytosis. In addition, adhesion of macrophages to recombinant fibronectins lacking α4β1 recognition motifs failed to promote phagocytosis of apoptotic neutrophils. Our results would be consistent with a model in which multiple fibronectin receptors, including β1 integrins, act cooperatively to augment macrophage phagocytic responses. Together, these data suggest that the extracellular matrix environment of macrophages may provide regulatory signals that act indirectly to rapidly alter the potential for removal of apoptotic cells and influence the process of resolution of inflammation. J. Leukoc. Biol. 64: 600–607; 1998.
Membrane depolarization and depletion of intracellular calcium stores are associated with delay of apoptosis in human neutrophils
Authors: Chacon-Cruz Enrique , Oelberg David G , Davis Paris , Buescher E Stephen
Published: January 2018

Apoptosis occurs rapidly in human polymorphonuclear leukocytes (PMN) after exposure to 1 mM cycloheximide (CHX). We examined whether this form of stimulated apoptosis altered either resting cytosolic free Ca2+ concentrations ([free Ca]) or membrane potential (Ψ) in PMN and found no significant effects. However, manipulation of either PMN intracellular Ca2+ stores or Ψ was found to delay CHX-induced apoptosis. Depletion of PMN intracellular Ca2+ stores with thapsigargin caused membrane depolarization and significantly delayed CHX-induced apoptosis based on both morphological and annexin-V-fluorescein isothiocyanate binding criteria. Short-term suspension (4 h) of PMN in Ca2+-free buffer depleted internal Ca2+ stores, induced membrane depolarization at 2.5 h, and delayed spontaneous (24 h) apoptosis but had no effect on CHX-induced apoptosis. Rapid membrane depolarization with 150 mM KCl buffer significantly delayed CHX-induced apoptosis, suggesting that depolarization rather than Ca2+ stores depletion was the crucial event. Timing experiments revealed that depolarization within 12 min of CHX exposure significantly delayed apoptosis. Collectively, these observations suggest an early Ψ-sensitive step in the apoptosis pathway initiated by CHX. CHX exposure alone does not alter either resting PMN [free Ca] or Ψ; accompanying depolarization of plasma membrane (either electrochemically or via depletion of internal Ca2+ stores) delays CHX-induced apoptosis in a time-dependent manner. J. Leukoc. Biol. 64: 759–766; 1998.
Integrin signal transduction in myeloid leukocytes
Authors: Lowell Clifford A , Berton Giorgio
Published: January 2018

Integrin-mediated adhesion serves as a powerful costimulus for neutrophil activation. Clustering of integrins at the leukocyte membrane by interaction with surface-bound ligands (extracellular matrix proteins or endothelial cell counter-receptors) leads to a number of signaling events that culminate in actin cytoskeletal rearrangement and neutrophil functional responses such as migration, degranulation, and respiratory burst. Although the signaling reactions elicited by integrin ligation are complex and the relative contribution of each pathway to neutrophil function is unclear, a large body of evidence suggests that activation of tyrosine kinases is a very proximal event in these signaling cascades. This review summarizes the role of adhesion in activating neutrophil functional properties and the contribution of leukocyte tyrosine kinases to regulation of integrin signaling in myeloid cells. Significant advances in our understanding of leukocyte integrin signaling have been afforded by studies using knockout mice lacking members of the Src-family of tyrosine kinases normally expressed in myeloid cells. These studies have demonstrated that these kinases (Hck, Fgr, and Lyn) are not required for myeloid cell development or for many of the functional properties of myeloid cells but are critical in controlling integrin-mediated signaling events. Absence of these kinases results in impaired adhesion-dependent neutrophil activation both in vivo and in vitro. These studies suggest that leukocyte-specific tyrosine kinases may be good therapeutic targets for controlling myeloid cell-dependent inflammatory disease. J. Leukoc. Biol. 65: 313–320; 1999.
The SIV-infected rhesus monkey model for HIV-associated dementia and implications for neurological diseases
Authors: Rausch Dianne M , Murray Elisabeth A , Eiden Lee E
Published: January 2018

The neuropathogenesis of human immunodeficiency virus (HIV)-associated dementia has remained elusive, despite identification of HIV as the causal agent. Although a number of contributing factors have been identified, the series of events that culminate in motor and cognitive impairments after HIV infection of the central nervous system (CNS) are still not known. Rhesus monkeys infected with simian immunodeficiency virus (SIV) manifest immunosuppression and CNS disease that is pathologically [L. R. Sharer et al. (1991) J. Med. Primatol. 20, 211–217] and behaviorally [E. A. Murray et al. (1992) Science 255, 1246–1249] similar to humans. The SIV model of HIV-associated dementia (HAD) is widely recognized as a highly relevant model in which to investigate neuropathogenesis. With better understanding of neuropathogenesis comes the opportunity to interrupt progression and to design better treatments for HAD. This becomes increasingly important as patients live longer yet still harbor HIV-infected cells in the CNS. The use of the SIV model has allowed the identification of neurochemical markers of neuropathogenesis important not only for HAD, but also for other inflammatory neurological diseases. J. Leukoc. Biol. 65: 466–474; 1999.
Intracellular oxidant production and cytokine responses in lung macrophages: evaluation of fluorescent probes
Authors: Imrich Amy , Ning YaoYu , Kobzik Lester
Published: January 2018

The fluorescent probes dichlorofluorescin (DCFH), dihydrorhodamine (DHR), and hydro- ethidine (HE) allow convenient assay of alveolar macrophage (AM) oxidant responses to environmental particulates and pathogens. We sought to more precisely define the relationship of these measures of oxidant stress to production of pro-inflammatory cytokines. Normal AMs were challenged in vitro with a panel of soluble or particulate stimuli in the presence of DCFH, HE, or DHR. Flow cytometry measured cell-associated fluorescence and relative particle uptake. Tumor necrosis factor α and macrophage inflammatory protein 2 expression were quantitated in the same experiments. We observed variable and complex correlations between intracellular oxidant production as reported by these probes and subsequent cytokine response, including examples of striking discordance (e.g., lipopolysaccharide induced large cytokine responses with minimal probe oxidation, whereas fly ash particles caused marked oxidation of DCFH but trivial TNF release; TiO2 caused oxidation of DHR and HE, but not DCFH, and also did not increase cytokine production). Although fluorescent probes offer many advantages in analysis of intracellular oxidant responses, the data indicate that they cannot be used reliably as quantitative predictors of AM cytokine responses to environmental particulates or other stimuli. J. Leukoc. Biol. 65: 499–507; 1999.
Chemokine immunobiology in HIV-1 pathogenesis
Authors: Leen Benhur , Montaner Luis J
Published: January 2018

The discovery of HIV-1-suppressive chemokines and the subsequent discovery of their cognate receptors as coreceptors for HIV-1 entry herald a paradigmatic shift in the study of HIV-1 pathogenesis. The presence of polymorphisms in chemokine receptor and chemokine genes associated with altered progression and susceptibility to the HIV-1 disease further underscores the potential importance that chemokines and their cognate receptors play in HIV-1 pathogenesis. It has become increasingly apparent that the immune system maintains a delicate balance between the positive and negative regulators that govern the chemokine and cytokine networks. Here we review the most recent developments in chemokine biology and relate how research into their structure, regulation, and the mechanism of their actions can shed light on the immunopathogenesis of HIV-1 disease. J. Leukoc. Biol. 65: 552–565; 1999.
Dramatic decrease of circulating levels of monocyte chemoattractant protein-1 in Kawasaki disease after gamma globulin treatment
Authors: Terai Masaru , Jibiki Toshiaki , Harada Akihisa , Terashima Yuya , Yasukawa Kumi , Tateno Shigeru , Hamada Hiromichi , Oana Shinji , Niimi Hiroo , Matsushima Kouji
Published: January 2018

Kawasaki disease (KD) is a systemic vasculitis preferentially affecting coronary arteries. Extensive monocytes/macrophages infiltrate in the vascular lesions, implying the involvement of a chemotactic cytokine in their recruitment. We investigated the role of monocyte chemoattractant protein-1 (MCP-1, also termed monocyte chemotactic and activating factor) in KD. In the immunohistochemical studies using the cardiac tissues of patients with fatal KD, MCP-1 but not interleukin (IL) -8 or macrophage inflammatory protein-1α was localized at the extracellular matrix associated with mononuclear cellular infiltration. The sites of MCP-1 expression correlated with the distribution of the acute inflammation, including early coronary vasculitis. In prospectively studied patients with KD, circulating levels of MCP-1, IL-8, tumor necrosis factor a (TNF-α), and IL-1α were elevated in 73, 77, 57, and 0% of samples before gamma globulin (GG) treatment (400 mg/kg × 5 days = total 2 g/kg), respectively, compared with respective control values. GG treatment correlated with a rapid decrease in the circulating levels of MCP-1 (P = 0.001) but not IL-8 (P = 0.19) or TNF-α (P = 0.33). In the sensitive Western blotting, MCP-1 bound to GG. Furthermore, GG inhibited the MCP-1-induced Ca2+ influx in a human monocytic cell line in vitro. These findings suggest a role of MCP-1 in KD, and indicate that GG treatment may block MCP-1 activity, thus alleviating KD vasculitis. J. Leukoc. Biol. 65: 566–572; 1999.
Demonstration of iNOS-mRNA and iNOS in human monocytes stimulated with cancer cells in vitro
Authors: Siedlar Maciej , Mytar Bozenna , Krzeszowiak Agnieszka , Baran Jaroslaw , Hyszko Mariola , Ruggiero Irena , Wieckiewicz Jerzy , Stachura Jerzy , Zembala Marek
Published: January 2018

Synthesis and localization of inducible nitric oxide synthase mRNA (iNOS-mRNA) and iNOS protein in the cultures of human monocytes (Mφ) and colon carcinoma cell line (DeTa) that resulted in nitric oxide (NO) synthesis has been studied. The iNOS-mRNA was observed around the sixth hour of culture and peaked at the twelfth hour. The iNOS-mRNA, as determined by the in situ hybridization and iNOS protein, as detected by staining with specific anti-iNOS monoclonal antibodies, were observed preferentially in the cytoplasm of some Mφ, but not in cancer cells. Mφ cultured alone did not show detectable iNOS-mRNA expression and iNOS protein. Mφ sorted out from tumor cells after 8hof co-culture expressed iNOS protein and iNOS-mRNA, which were not detected in Mφ without previous contact with cancer cells. Prevention of NO synthesis by (L-N5-1-iminoethyl)-ornithine (L-NIO) partly inhibited Mφ cytotoxic activity against DeTa (NO-inducing cancer cell line) but not against the human pancreatic cancer (HPC-4) cell line that does not induce NO production in Mφ. This suggests that Mφ cytotoxic activity, at least in some cases, may be NO dependent. These observations provide further evidence that Mφ can be directly stimulated by cancer cells for de novo production of NO and suggest that iNOS occurring in the tumor-infiltrating macrophages may arise as a result of their interactions with tumor cells. However, because only some tumor cells are able to induce NO production in a small proportion of Mφ, its role in the anti-tumor response of the host is probably limited. J. Leukoc. Biol. 65: 597–604; 1999.
Interaction with vesicular stomatitis virus-infected BALB/c3T3 cells inhibits the synthesis of nitric oxide in activated murine bone marrow culture-derived macrophages
Authors: Crowder Chun W , Murphy William J , Russell Stephen W , LeBlanc Paul A
Published: January 2018

Bone marrow-culture-derived macrophages activated with interferon-γ and lipopolysaccharide produced less nitric oxide (NO) when cultured with vesicular stomatitis virus (VSV)-infected BALB/c3T3 (3T3-VSV) than macrophages activated in an identical manner and cultured alone, with uninfected BALB/c3T3 (3T3), or with P815. However, all four groups of macrophages produced nearly the same amount of interleukin-6 (IL-6). Addition of VSV to activated macrophages did not change the amount of NO produced. The amount of NO generated by two non-macrophage sources of NO was not affected by the presence of either P815 or 3T3-VSV. Reverse transcriptase-polymerase chain reaction showed a decrease in the amount of inducible nitric oxide synthase (iNOS) but not IL-6 mRNA from macrophages cocultured with 3T3-VSV compared with macrophages cocultured with P815. The reduction in iNOS mRNA was confirmed by ribonuclease protection assay. When RAW 264.7 transfected with an iNOS regulatory construct were activated and incubated with 3T3-VSV there was a decrease in the expression of the reporter luciferase gene and NO production but not IL-6 production compared with cells incubated with either medium alone or with P815. J. Leukoc. Biol. 65: 605–613; 1999.
Hyperglycemia in vitro attenuates insulin-stimulated chemokinesis in normal human neutrophils. Role of protein kinase C activation
Authors: Oldenborg Per-Arne , Sehlin Janove
Published: January 2018

This study was performed to test whether the inhibitory effect of elevated D-glucose concentrations on insulin-stimulated chemokinesis in normal human neutrophils is mediated by increase in protein kinase C (PKC) activity. Activation of PKC with phorbol 12-myristate 13-acetate (PMA) at 0–100 nM dose-dependently inhibited neutrophil random locomotion in the absence of insulin. Suboptimal concentrations of PMA (0.1–0.5 nM) inhibited the chemokinetic effect of 160 μU/mL insulin in a dose-dependent way. The specific PKC inhibitor bisindolylmaleimide (GF 109203x) did not affect the insulin-stimulated chemokinesis at 5 mM glucose but restored the chemokinetic effect of insulin at 15 mM glucose. These results therefore suggest that glucose-induced PKC activation may mediate the inhibitory effects of high glucose levels on insulin-stimulated chemokinesis in normal human neutrophils. J. Leukoc. Biol. 65: 635–640; 1999.
Enhancement of leukocyte response to lipopolysaccharide by secretory group IIA phospholipase A2
Authors: Cai Tian-Quan , Thieblemont Nathalie , Wong Birming , Thieringer Rolf , Kennedy Brian P , Wright Samuel D
Published: January 2018

Secretory nonpancreatic group IIA Phospholipase A2 (sPLA2), a lipolytic enzyme found in plasma, is thought to play an important role in inflammation. In patients with sepsis, a strong positive correlation is observed between the plasma level of sPLA2 and poor clinical outcome in sepsis. We have thus asked whether sPLA2 could play a role in enabling responses of cells to bacterial lipopolysaccharide (LPS), a key contributor to sepsis. In the presence of sPLA2, cellular responses to LPS were significantly increased. This was demonstrated in assays of LPS-stimulated interleukin-6 (IL-6) production in whole blood and binding of freshly isolated human polymorphonuclear neutrophils (PMN) to fibrinogen-coated surfaces. We further found that sPLA2 enhanced binding of labeled LPS to PMN, and that the sPLA2-mediated cell responses to LPS were all blocked by monoclonal antibodies directed against membrane CD14. Two properties of sPLA2 may contribute to its activity to mediate responses to LPS. sPLA2 appears to bind LPS because pre-exposure of sPLA2 to LPS led to a dose-dependent increase in its ability to hydrolyze phospholid substrate, and incubation of sPLA2 with BODIPY-LPS micelles resulted in enhanced fluorescence, presumably from the disaggregation of the LPS aggregates. Additional studies demonstrated that the esterolytic function of sPLA2 is also needed both for the disaggregation of LPS and CD14-dependent cell stimulation. The precise mechanisms by which LPS-binding and esterolytic activity contribute to sPLA2 activity are not clear but our data strongly suggest that these activities result in interaction of LPS with CD14 and subsequent cell activation. J. Leukoc. Biol. 65: 750–756; 1999.
An autologous self-antigen differentially regulates expression of I-A glycoproteins and B7 costimulatory molecules on CD4− CD8− T helper cells
Authors: Walker Mindi R , White Gregory A , Nardella John P , Mannie Mark D
Published: January 2018

During inflammation, T helper cells transiently express class II major histocompatibility complex (MHC) glycoproteins and present antigens to other T cells. To assess involvement of self-antigens in the generation of T cell antigen-presenting cell (T-APC) activity, rat (R) myelin basic protein (MBP) was used to stimulate a rat CD4−CD8− T cell clone. RMBP induced T cell surface expression of class II MHC glycoproteins and T-APC activity, although RMBP did not elicit interleukin (IL-2) production or proliferation. When added to culture with the strong agonist guinea pig (GP) MBP, RMBP acted as a partial antagonist and inhibited responses of IL-2 production, proliferation, and T cell expression of B7.1. RMBP did not, however, efficiently antagonize GPMBP-induced I-A expression on T cells. These findings indicate that the self-antigen RMBP specifically induces accumulation of I-A/peptide complexes at signaling thresholds that inhibit pathogenic autoimmune responses. Overall, this study suggests a role for self-antigens in the generation of B7-deficient T-APC activity as a mechanism of tolerance in experimental autoimmune encephalomyelitis. J. Leukoc. Biol. 66: 120–126; 1999.
Modulation of CXCR4 expression and SDF-1α functional activity during differentiation of human monocytes and macrophages
Authors: Gupta Shalley K , Pillarisetti Kodandaram , Lysko Paul G
Published: January 2018

Chemoattraction of monocytes by the CXC chemokine stromal cell-derived factor-1α (SDF-1α) and its receptor CXCR4 may be involved in vascular diseases like atherosclerosis. We studied the regulation of CXCR4 transcription and SDF-1-induced functional responses in human monocytes during their differentiation in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), oxidized low-density lipoprotein (Ox-LDL), and unmodified LDL. Our results reveal that the rapid decline of SDF-1-mediated [Ca2+]i influx after monocyte isolation is followed by a gradual functional restoration and a concomitant re-expression of CXCR4 mRNA over time. A further three- to fourfold induction of CXCR4 mRNA occurred in macrophage-derived foam cells on treatment with Ox-LDL. HL-60 cells induced with phorbol myristate acetate (PMA) showed a rapid fourfold stimulation of CXCR4 mRNA within 1 h, declining to barely detectable levels at 3 h, with eventual restoration over time, mirroring the expression pattern in monocytes. Surface expression of CXCR4 is maintained in HL-60 cells during PMA-induced differentiation, as demonstrated by flow cytometry. GM-CSF had no effect on CXCR4 mRNA in HL-60 cells and does not cause its down-regulation in human macrophages. J. Leukoc. Biol. 66: 135–143; 1999.
The initiation of the neutrophil chemotactic response in filters
Authors: Ebrahimzadeh P R , Braide M
Published: January 2018

The fluid gradient chamber was used to study the migration of human neutrophils in preformed gradients of N-formyl-methionyl-leucyl-phenylalanine. After 60 min, the chemotactic gradient was replaced by a new one of identical steepness but opposite direction. In a control group of experiments, the first gradient was retained. Migration was assessed from cell distributions in filter sandwiches after 30, 60, and 90 min. Filters obtained after 5, 15, and 30 min of migration were stained with fluorescent phalloidin for microscopic evaluations of cell polarity. At 30 min most cells had polarized in vertical directions and invaded the filters. The distance of chemotactic migration was similar during the second and the third 30-min periods (although the direction of migration was reversed in the new gradient) and significantly greater than during the first 30 min. In conclusion, the initial slow response to the chemotactic gradient represents an adaptation of the cells that later respond promptly to changes in gradient direction. J. Leukoc. Biol. 66: 90–94; 1999.
Infusion of donor leukocytes to induce tolerance in organ allograft recipients
Authors: Salgar S K , Shapiro R , Dodson F , Corry R , McCurry K , Zeevi A , Pham S , Abu-Elmagd K , Reyes J , Jordan M , Keenan R , Griffith B , Sesky T , Ostrowski L , Starzl T E , Fung J J , Rao A S
Published: January 2018

To further enhance chimerism, 229 primary allograft recipients have received perioperative intravenous infusion of a single dose of 3 to 6 × 108 unmodified donor bone marrow (BM) cells/kg body weight. In addition, 42 patients have been accrued in a concurrent protocol involving multiple (up to three) sequential perioperative infusions of 2 × 108 BM cells/kg/day from day 0–2 posttransplantation (PTx). Organ recipients (n = 133) for whom BM was not available were monitored as controls. The infusion of BM was safe and except for 50 (18%), all study patients have optimal graft function. Of the control patients, allografts in 30 (23%) have been lost during the course of follow-up. The cumulative risk of acute cellular rejection (ACR) was statistically lower in the study patients compared with that of controls. It is interesting that, 62% of BM-augmented heart recipients were free of ACR (Grade ≥ 3A) in the first 6 months PTx compared to controls. The incidence of obliterative bronchiolitis was also statistically lower in study lung recipients (3.8%) compared with the contemporaneously acquired controls (31%). The levels of donor cell chimerism were at least a log higher in the peripheral blood of majority of the study patients compared with that of controls. The incidence of donor-specific hyporeactivity, as determined by one-way mixed leukocyte reaction, was also higher in those BM-augmented liver, kidney, and lung recipients that could be evaluated compared to controls. J. Leukoc. Biol. 66: 310–314; 1999.
Ubiquicidin, a novel murine microbicidal protein present in the cytosolic fraction of macrophages
Authors: Hiemstra Pieter S , van den Barselaar Maria T , Roest Mark , Nibbering Peter H , van Furth Ralph
Published: January 2018

Previously we have identified and characterized three murine microbicidal proteins purified from the granule fraction of cells from the murine macrophage cell line RAW264.7. During these studies evidence was obtained for the presence of an additional antimicrobial protein in the cytosolic fraction of RAW264.7 cells that had been activated with interferon-γ (IFN-γ). In this study we have purified this protein, designated ubiquicidin, to apparent homogeneity and demonstrated that it is a cationic, small (Mr 6654) protein. Ubiquicidin displayed marked antimicrobial activity against Listeria monocytogenes and Salmonella typhimurium. Using a gel overlay procedure evidence was obtained that the protein also displays activity against Escherichia coli, Staphylococcus aureus, and an avirulent strain of Yersinia enterocolitica. Amino-terminal amino acid sequencing and mass spectrometry analysis of purified ubiquicidin indicated that it is most likely identical to the ribosomal protein S30. This protein is produced by posttranslational processing of the Fau protein, a 133-amino-acid fusion protein consisting of S30 linked to an unusual peptide with significant homology to ubiquitin. The fau gene has been reported to be expressed in a variety of tissues in humans and various animal species. The presence of ubiquicidin in the cytosol of macrophages may serve to restrict the intracellular growth of microorganisms. In addition, because macrophage disintegration will likely lead to release of ubiquicidin into the extracellular environment, it may contribute to host defense after macrophage death. J. Leukoc. Biol. 66: 423–428; 1999.
The generation of human dendritic and NK cells from hemopoietic progenitors induced by interleukin-15
Authors: Bykovskaia Svetlana N , Buffo Mary , Zhang Haifan , Bunker Mark , Levitt Mark L , Agha Mounzer , Marks Stanley , Evans Carol , Ellis Peter , Shurin Michael R , Shogan Jeffrey
Published: January 2018

Interleukin-15 (IL-15) is a pleiotropic cytokine that induces the generation and differentiation of lymphoid cells and shares many biological activities with IL-2. We have shown here the development of dendritic cells (DC) from human CD34+ hemopoietic precursor cells cultured for 2–4 weeks with IL-15 alone. DC generated with IL-15 have typical morphological, immunocytochemical, phenotypic, and functional characteristics of mature DC. Dual flow cytometry analysis performed weekly demonstrated increasing co-expression of CD1a or CD83 with HLA-DR, CD80, CD86, IL-2R α, β, and γ. Two populations of cells were distinguished among CD34+ progeny. Small and medium-size cells were mainly natural killer (NK) cells (72.6–85.2% CD56+) and low numbers of DC (9.1–21.3% CD1a+). Large cells were mostly DC (75.4–95.4% CD1a+). Isolated CD34+ cells did not express IL-2R subunits but after 2–3 days in culture with IL-15, they were found to express IL-2Rγ. Induced expression of IL-2Rγ on CD34+ cells may explain the primary mechanism of IL-15-regulated differentiation of hemopoietic precursor cells. Thus, our data suggest that IL-15 stimulates CD34+ cells to differentiate into NK and DC and may represent a new growth and survival factor for lymphoid DC. J. Leukoc. Biol. 66: 659–666; 1999.
Macrophages: important accessory cells for reproductive function
Authors: Cohen Paula E , Nishimura Kayoko , Zhu Liyin , Pollard Jeffrey W
Published: January 2018

Macrophages are found throughout reproductive tissues. To determine their role(s), we have studied mice homozygous for a null mutation (Csfmop) in the gene encoding the major macrophage growth factor, colony-stimulating factor-1 (CSF-1). Both male and female Csfmop/Csfmop mice have fertility defects. Males have low sperm number and libido as a consequence of dramatically reduced circulating testosterone. Females have extended estrous cycles and poor ovulation rates. CSF-1 is the principal growth factor regulating macrophage populations in the testis, male accessory glands, ovary, and uterus. However, analyses of CSF-1 nullizygous mice suggest that the primary reproductive defect is in the development of feedback regulation of the hypothalamic-pituitary axis. Although not correlating with deficiencies of microglia populations, electrophysiological investigations indicate an impairment of neuronal responses. This suggests that microglia, under the influence of CSF-1, act to organize neuronal connectivity during development and that the absence of this function results in a perturbation of the hypothalamicpituitary-gonadal axis. Macrophages also appear to have functions in the differentiated tissues of the reproductive system, including having a positive influence on steroidogenic cells. These data suggest that macrophages, through their trophic functions, can be considered as essential accessory cells for normal reproductive functioning. J. Leukoc. Biol. 66:765–772; 1999.
Inflammatory agents regulate in vivo expression of fractalkine in endothelial cells of the rat heart
Authors: Harrison Jeffrey K , Jiang Yan , Wees Elizabeth A , Salafranca Mina N , Liang Hui-Xiu , Feng Lili , Belardinelli Luiz
Published: January 2018

Fractalkine is distinguished structurally from other chemokines in that it contains a mucinlike stalk that tethers a CX3C chemokine module to a transmembrane-spanning region; its expression in cultured endothelial cells has been shown to be up-regulated by tumor necrosis factor α (TNF-α) and interleukin-1 (IL-1). The purpose of this study was to determine whether fractalkine is expressed, in a proinflammatory agent-regulated manner, by cardiac endothelial cells in vivo. Steady state levels of fractalkine mRNA were increased in rat cardiac tissues after in vivo treatment with lipopolysaccharide (LPS), IL-1, or TNF-α. In situ hybridization and immunohistochemical analysis revealed that endothelial cells of the coronary vasculature and endocardium were the principal source of proinflammatory agent-inducible fractalkine, although some fractalkine immunoreactivity was also found on the myocytes. These data are the first demonstration of in vivo cardiac endothelial cell fractalkine expression and regulation by proinflammatory agents such as LPS, IL-1, or TNF-α. Cardiac endothelial cell-expressed fractalkine may contribute to the influx of leukocytes into the heart during inflammation. J. Leukoc. Biol. 66: 937–944; 1999.
Role of endothelins on lymphocyte accumulation in allergic pleurisy
Authors: Sampaio André L F , Rae Giles A , das Graças Maria , Henriques M O
Published: January 2018

Endothelins participate in different aspects of inflammatory reactions, including edema formation and eosinophil accumulation in allergic reaction. In this study, we demonstrated a role for endogenous endothelins in eosinophil and T lymphocyte recruitment and cytokine secretion in a murine model of allergic inflammation. Intrathoracic stimulation with endothelin-1 triggered a neutrophil accumulation at 4 h, concomitant with an increase of CD4+ and CD8+ T lymphocyte populations. Antigen challenge in sensitized animals leads to an increase in eosinophil and mononuclear cell numbers at 24 h. Treatment with ETA receptor antagonist (BQ123) inhibited antigen-induced eosinophil and mononuclear cell migration, whereas the selective ETB receptor antagonist BQ-788 was ineffective. The latter effect of BQ-123 was due to inhibition of CD4+ and CD8+ T lymphocytes. Treatment with BQ-123 also inhibited interleukin-5 levels in the exudate and plasma as well as intracellular staining of interleukin-4, interleu-kin-5, and interferon-γ in CD4+ lymphocytes. These findings suggest that endogenous endothelins contribute to allergic inflammation by modulating lymphocyte recruitment and cytokine production. J. Leukoc. Biol. 67: 189–195; 2000.
Activation of macrophages by food antigens: enhancing effect of gluten on nitric oxide and cytokine production
Authors: Tuçková Ludmila , Flegelová Zuzana , Tlaskalová-Hogenová Helena , Zídek Zdenek
Published: January 2018

Macrophages play an important role in effector mechanisms of various chronic inflammatory diseases. We studied the effect of gluten, the agent inducing celiac disease, and other food antigens on the activation of macrophages. Nitric oxide (NO) and cytokine production were followed as markers of activation, using cultured murine peritoneal macrophages. None of the food antigens tested caused direct inducible nitric oxide synthase (iNOS) activation in macrophages. Unlike other food antigens gluten, gliadin, and their proteolytic fragments significantly enhanced NO production when applied together with interferon-γ (IFN-γ), the most efficient being fragments originating from 25-to 45-min peptic digestion. The activation pathway was mediated via direct stimulation of tumor necrosis factor α (TNF-α) secretion. The NO-enhancing effect was confirmed at the level of iNOS mRNA transcription. In case of sustained local inflammatory reaction connected with increase of IFN-γ, gluten and its proteolytic fragments may thus elevate NO production. Increased NO level could consequently participate in the development of mucosal lesions in the gut of celiac patients. J. Leukoc. Biol. 67: 312–318; 2000.
A beneficial aspect of a CB1 cannabinoid receptor antagonist: SR141716A is a potent inhibitor of macrophage infection by the intracellular pathogen Brucella suis
Authors: Gross Antoine , Terraza Annie , Marchant Jean , Bouaboula Monsif , Ouahrani-Bettache Safia , Liautard Jean-Pierre , Casellas Pierre , Dornand Jacques
Published: January 2018

The psychoactive component of marijuana, δ-tetrahydrocannabinol (THC) suppresses different functions of immunocytes, including the antimicrobicidal activity of macrophages. The triggering of cannabinoid receptors of CB1 and CB2 subtypes present on leukocytes may account for these effects. We investigated the influence of specific CB1 or CB2 receptor antagonists (SR141716A and SR144528, respectively) and nonselective CB1/CB2 cannabinoid receptor agonists (CP55,940 or WIN 55212-2) on macrophage infection by Brucella suis, an intracellular gram-negative bacteria. None of the compounds tested affected bacterial phagocytosis. By contrast, the intracellular multiplication of Brucella was dosedependently inhibited in cells treated with 10–500 nM SR141716A and 1 μM SR141716A-induced cells exerted a potent microbicidal effect against the bacteria. SR144528, CP55,940, or WIN 55212-2 did not affect (or slightly potentiated) the growth of phagocytized bacteria. However, CP55,940 or WIN 55212-2 reversed the SR141716A-mediated effect, which strongly suggested an involvement of macrophage CB1 receptors in the phenomenon. SR141716A was able to pre-activate macrophages and to trigger an activation signal that inhibited Brucella development. The participation of endogenous cannabinoid ligand(s) in Brucella infection was discussed. Finally, our data show that SR141716A up-regulates the antimicrobial properties of macrophages in vitro and might be a pharmaceutical compound useful for counteracting the development of intramacrophagic gram-negative bacteria. J. Leukoc. Biol. 67: 335–344; 2000.
Isolation of MYADM, a novel hematopoietic-associated marker gene expressed in multipotent progenitor cells and up-regulated during myeloid differentiation
Authors: Pettersson Monica , Dannaeus Karin , Nilsson Kenneth , Jönsson Jan-Ingvar
Published: January 2018

A large number of hematopoietic cytokines and their receptors as well as transcription factors have been shown to be involved in maturation of blood cells. However, many of the genes important for the differentiation of multipotent stem cells to specific cellular lineages are still unknown. To identify novel genes involved in lineage selection of myeloid cells, we have applied differential display analysis during commitment toward granulocytes and macrophages of an IL-3-dependent multipotent progenitor cell line, FDCP-mix. One regulated cDNA represented a novel gene with restricted expression pattern within the hematopoietic system and was strongly up-regulated when FDCP-mix cells differentiated in GM-CSF, G-CSF, and M-CSF. The expression appears to be differentiation stage-specific in myeloid cells and is absent in B and T lymphocytes. Thus we found expression in normal mouse bone marrow enriched for stem cells and multipotent progenitors (c-kit+Sca-1+Lin− cells). When these cells were induced to differentiate toward myeloid cells, MYADM was up-regulated. In contrast, during conditions known to favor the development of B cell progenitors, the gene was down-regulated. The gene, termed MYADM for myeloid-associated differentiation marker gene, shows 100% identity to expressed sequence tags from early mouse embryonic development as well as from the mouse lung and from activated mouse macrophages. The predicted 32-kDa MYADM protein contains multiple hydrophobic putative transmembrane segments and has several potential consensus sites for phosphorylation. In view of its expression pattern, MYADM could serve as a new marker gene for hematopoietic differentiation. Although the function is unknown, antisense oligonucleotides were able to inhibit colony formation of c-kit+ Lin− bone marrow cells, suggesting an important role for MYADM in myeloid differentiation. J. Leukoc. Biol. 67: 423–431; 2000.