bluuebunny/crossref_metadata_2025 huggingface dataset:
The heavy metal lead modulates the expression of both TNF-α and TNF-α receptors in lipopolysaccharide-activated human peripheral blood mononuclear cells
Authors: Guo Tai Liang , Mudzinski Stanley P , Lawrence David A
Published: January 2018

It has been shown that lead (Pb) potentiates lipopolysaccharide (LPS) lethality in animals by increasing the secretion and uptake or reactivity of tumor necrosis factor-α (TNF-α). Herein we report that PbCl2 increased TNF-α secretion from LPS-treated human peripheral blood mononuclear cells (PBMC) in a concentration- and time-dependent manner. PbCl2 also increased total cellular TNF-α levels but had no effect on the steady-state levels of TNF-α mRNA. PbCl2 decreased membrane-associated TNF-α (mTNF-α) on LPS-treated monocytes, whereas PbCl2 increased TNF-α receptor (TNF-R) p55 surface expression, and had no effect on TNF-R p75 surface expression by LPS-treated monocytes. Overall, the results suggest that PbCl2 increases TNF-α expression by posttranscriptional mechanisms in human PBMC, and enhances the reactivity and uptake of TNF-α by increasing the surface expression of TNF-R p55.
The role of early growth response gene 1 (egr-1) in regulation of the immune response
Authors: McMahon Steven B , Monroe John G
Published: January 2018

The induction of immediate early genes in cells of the immune system is critical to determining the ultimate outcome of exposure to antigen. The importance of many of these genes relates to the role their transcription factor products play in dictating patterns of expression of downstream, function-related genes. Evidence from several systems indicates that the immediate early gene, egr-1 may be of particular importance in the immune system. Recently, the egr-1 promoter has been shown to be highly responsive to the diverse biochemical signals generated by antigen and cytokines in cells of the immune system. Furthermore, an important role for egr-1 in determining the differentiation pathway of myeloid cell precursors has been recently elaborated. Finally, potential targets of regulation by the zinc-finger transcription factor encoded by egr-1 include the interleukin-2, CD44, ICAM-1, and tumor necrosis factor genes. The role of egr-1 in regulation of the immune response will be discussed in the context of these recent studies.
Anti-CD69 antibodies enhance phorbol-dependent glucose metabolism and Ca2+ levels in human thymocytes. Antagonist effect of cyclosporin A
Authors: Conde M , Montaño R , Moreno-Aurioles V R , Ramirez R , Sanchez-Mateos P , Sanchez-Madrid F , Sobrino F
Published: January 2018

The human activation antigen CD69 is an early inducible surface glycoprotein acquired by T cells in the thymus at the stage of positive selection and during activation of mature lymphoid cells both in vivo and in vitro. We have studied the regulatory influence of CD69 activation pathway on the glycolytic process and transduction signals of thymocytes. Treatment of human thymocytes with different anti-CD69 monoclonal antibodies (mAbs), in the presence of submitogenic doses of phorbol ester, produced an enhanced release of lactate without significant alterations in Fru 2,6-P2 levels or phosphofructokinase-2 (PFK-2) and pyruvate kinase activities. A small increase in phosphofructokinase-1 (PFK-1) activity was also detected. Furthemore, anti-CD69 mAb increased the glucose detritiation from [2-3H] and [3-3H]glucose, thus indicating an enhanced flux through hexokinase and PFK-1 steps. In addition, de novo synthesis of diacylglycerol and intracellular Ca2+ levels increased after anti-CD69 mAb treatment. The stimulatory effects of anti-CD69 mAb on both glycolysis and Ca2+ levels were inhibited by cyclosporin A. Because CD69 molecules are present in certain subset populations of immature thymocytes, the ability of anti-CD69 mAb to stimulate the glycolysis, the synthesis of diacylglycerol and the intracellular Ca2+ levels suggest that the activation signals delivered through CD69 molecules could play a role in the thymus cells maturation.
Glycated serum albumin induces chemokine gene expression in human retinal pigment epithelial cells
Authors: Bian Zong-Mei , Elner Susan G , Strieter Robert M , Glass Mary B , Lukacs Nicholas W , Kunkel Steven L , Elner Victor M
Published: January 2018

Chronic hyperglycemia is thought to be important in the development of diabetic neovascularization but the mechanisms involved remain poorly understood. Interleukin-8 (IL-8) is a leukocyte chemokine and activating agent with angiogenic properties that is present in diabetic vitreous and may play a role in diabetic vasculopathy. We studied IL-8 and monocyte chemotactic protein-1 (MCP-1) production by human retinal pigment epithelial (hRPE) cells exposed to glycated human serum albumin (GHSA). Enzyme-linked immunoassay GHSA (500 μg/mL)-treated hRPE cells secreted levels of IL-8 and MCP-1 detectable within 4 h and reached 26.0 ± 1.3 and 42.2 ± 0.4 ng/106 cells/mL after 24 h, respectively. Induction of IL-8 and MCP-1 by GHSA at concentrations ranging from 62.5 to 3,000 μg/mL exhibited dose-dependent kinetics. The GHSA-induced chemokine secretion by hRPE was almost completely inhibited by actinomycin D and cycloheximide, suggesting that de novo mRNA and protein synthesis are necessary for the GHSA-induced IL-8 and MCP-1 production. Northern blot analysis of GHSA-induced hRPE IL-8 and MCP-1 mRNA expression corresponded to the time- and dose-dependent increases measured by enzyme-linked immunosorbent assay. High concentrations of glucose (20 mM; 360 mg/dl) increased GHSA-induced hRPE IL-8 and MCP-1 secretion, whereas added insulin (0.5 ng/mL) inhibited IL-8 but not MCP-1 protein secretion and mRNA expression. GHSA also induced hRPE to secrete GRO-α, RAN-TES, and NAP-2 chemokines. GHSA induction of hRPE chemokines further suggests a role for the hRPE in leukocyte infiltration, vascular injury, and neovascularization.
Expression of the activated (Y501-F501) hck tyrosine kinase in 32Dcl3 myeloid cells prolongs survival in the absence of IL-3 and blocks granulocytic differentiation in response to G-CSF
Authors: English B Keith
Published: January 2018

The hematopoietic cell kinase (hck), a member of the src family of intracellular, membrane-associated protein tyrosine kinases, is primarily expressed in mature granulocytes and monocyte/macrophages.
The use of chimeric human Fcε receptor I to redirect cytotoxic T lymphocytes to tumors
Authors: Kershaw Michael H , Darcy Phillip K , Trapani Joseph A , Smyth Mark J
Published: January 2018

Chimeric receptors that redirect effector cell function to tumor cells or virus-infected cells have received much attention. Given the high affinity of FcRI for immunoglobulin E (IgE) and low serum IgE levels, redirection of effector cells using Fc receptor may provide a novel, versatile, and effective anti-tumor strategy. We have used a mouse perforin 5'-promoter to express a single-chain human Fc receptor in the mouse cytotoxic T lymphocyte cell line, CTLL-R8. Upon ligation of the chimeric Fc receptors by IgE, a signal for effector function is transmitted via the intracellular domain of CD3. Selection in G418-contaming medium produced CTLL-R8 transfectant clones that: (1) expressed chimeric Fc receptor as determined by flow cytometry; (2) bound human IgE antibodies with high affinity as determined by Scatchard analysis; (3) specifically rosetted IgE-coated SRBC; (4) lysed target cells in IgE-mediated ADCC and reverse ADCC assays; and (5) retarded tumor growth in a Winn assay. Therefore these chimeric Fc receptors can effectively redirect cytotoxicity to tumor cells. Future efforts will assess the versatility and efficacy of these IgE-binding chimeric receptors to redirect killer cell function in animal tumor models.
Dynamic imaging of neutrophil migration in three dimensions: mechanical interactions between cells and matrix
Authors: Mandeville John T H , Lawson Moira A , Maxfield Frederick R
Published: January 2018

Fluorescence confocal microscopy was used to obtain three-dimensional (3-D) images of human neutrophils migrating through a 3-D matrix of amniotic membrane with a temporal resolution of 30–60 s and a spatial resolution of 2 μm in the z-dimension. Neutrophils migrating in response to a chemoattractant gradient within a 3-D matrix were apparently able to generate traction by use of lateral pseudopods inserted into footholds in the matrix as evidenced by matrix distortion. Similar anchored pseudopods were seen in cells migrating across polycarbonate membranes with 0.8-μm pores; the presence of these pores increased cell polarization and migration compared with cells on membranes without pores. Expansion of pseudopods distal to narrow constrictions in the matrix and porous filters was observed and appeared to be used to pull cells through the openings. Neutrophils deformed parts of the elastic amnion matrix during migration without permanently altering the substrate. Contact guidance of neutrophils crawling along matrix fibrils was also observed. These observations show that neutrophils migrating in 3-D are able to utilize mechanical structures in the matrix, not present on 2-D surfaces, to generate traction for locomotion.
Identification of the mouse calcium-binding proteins, MRP 8 and MRP 14, in Schistosoma mansoni-induced granulomas: biochemical and functional characterization
Authors: Yang Tzung-Horng , Tzeng Sinfu , Cheng I , Burnett Mark G , Yoshizawa Yusuke , Fukuyama Kimie , Lee Sheng-Chung , Epstein William L
Published: January 2018

Granuloma Initiation factor (GIF), which elicits a granulomatous reaction in naive murine skin, contains low-molecular-weight proteins partially purified from organized granulomas developed in livers of mice with schistosomiasis. In this study, we found that 10- and 14-kDa proteins in the GIF are highly homologous to mouse migration inhibitory factor-related protein (MRP) 8 and MRP 14. Compared with the N-terminal amino acid sequence deduced from each corresponding cDNA, the 10-kDa protein from the granuloma lacks the first methionine, whereas the 14 kDa misses methionine, alanine, and asparagine. Immunohistochemically, cells expressing MRP 8 and MRP 14 considerably increased in different murine tissues after Schistosoma mansoni infection and concentrated in liver around the dilated bloodvessels and at the edge of granulomas. The staining of differentiated macrophages and epithelioid cells located in the center of the granulomas was negative. Immunoreactivity of peritoneal exudate cells also was found to gradually disappear with time in cell culture. Furthermore, in vivo effects of the recombinant proteins in murine skin were described histologically. Both MRPs caused severe infiltration of neutrophils and monocytes during 7–14 days. The reaction resulting from individual MRP implantation became minimal after 50 days but inoculation of the Ca2+-dependent heterodimers showed an extensive eosinophil accumulation.
Signaling mechanisms and the activation of leukocyte integrins
Authors: Newton Rebecca A , Thiel Martin , Hogg Nancy
Published: January 2018

Myeloid cells and lymphocytes primarily circulate in the vascular system but move into the tissues in response to inflammatory signals. Such a mobile lifestyle necessitates the continual making and breaking of cell and cell matrix contacts; the receptors known as the integrins are well suited as mediators of this transient adhesiveness. In general, leukocyte integrins are not constitutively active but become adhesive in response to signaling through other membrane receptors. Candidate receptors for receiving the activating signals are the seven membrane-spanning receptors that are found on all leukocytes. The identity of the signals, however, that are responsible for triggering integrin adhesion in vivo and for promoting directed leukocyte movement into tissues remains incompletely resolved.
Rapid induction of neutrophil apoptosis by sulfasalazine: implications of reactive oxygen species in the apoptotic process
Authors: Akahoshi Tohru , Namai Rie , Sekiyama Naho , Tanaka Sumiaki , Hosaka Shigeru , Kondo Hirobumi
Published: January 2018

Accumulating evidence indicates that neutrophils are crucially involved in the pathogenesis of inflammatory bowel diseases and rheumatoid arthritis. We therefore investigated the effect of sulfasalazine (SSZ), which is widely used in the treatment of these diseases, on neutrophil apoptosis in vitro. The apoptosis of neutrophils was determined by morphology, a DNA histogram of propidium iodide-stained nuclei, and DNA fragmentation. SSZ rapidly accelerated the rate of spontaneous neutrophil apoptosis within clinically relevant concentrations. This effect is unique to neutrophils because other types of leukocytes and a number of leukocyte cell lines are resistant to SSZ. Neutrophil apoptosis caused by SSZ was abrogated by a tyrosine kinase inhibitor, a protein kinase A inhibitor, and antioxidants. The subsequent results provided pharmacological evidence that the phosphorylation of tyrosine kinase and protein kinase A and generation of reactive oxygen species are involved in SSZ-mediated neutrophil apoptosis. These data suggest that SSZ-induced neutrophil apoptosis may account, in part, for the clinical benefits of SSZ on inflammatory bowel diseases and rheumatoid arthritis.
Anti-inflammatory action of dapsone: inhibition of neutrophil adherence is associated with inhibition of chemoattractant-induced signal transduction
Authors: Debol Steven M , Herron Michael J , Nelson Robert D
Published: January 2018

Dapsone has clinical utility as an anti-inflammatory agent but the mechanism of this action remains unknown. We have previously reported that dapsone inhibits β2 integrin (CD11b/CD18) -mediated adherence of human neutrophils in vitro and now describe studies designed to discover how dapsone-mediated inhibition of this neutrophil function occurs. Results indicate that dapsone interferes with the activation or function of the G-protein (Gi type) that initiates the signal transduction cascade common to chemotactic stimuli. They also show that dapsone-mediated suppression of this pathway inhibits the generation of second messengers essential to the activation of β2 integrin molecules, as well as respiratory and secretory functions of neutrophils exposed to chemoattractants. We propose that the inhibition of chemoattractant-induced signal transduction by dapsone suppresses neutrophil recruitment and local production of toxic respiratory and secretory products in the affected skin of dermatitis herpetiformis and other neutrophilic dermatoses.
Transcriptional regulation in the immune system: all roads lead to AP-1
Authors: Foletta Victoria C , Segal David H , Cohen Donna R
Published: January 2018

The mechanisms regulating the development and function of the immune system are diverse and complicated. The signaling pathways and target genes that become activated upon cell-surface stimulation are currently being defined, and transcription factor activator protein 1 (AP-1) is proving to be an important regulator of nuclear gene expression in leukocytes. In vitro and in vivo studies have demonstrated that AP-1 expression is induced after a diverse range of stimuli and that AP-1 contributes to the regulation of a large number of genes. In this review we will examine the role of AP-1 during leukocyte activation and differentiation in the immune system.
Gallium arsenide differentially affects processing of phagolysosomal targeted antigen by macrophages
Authors: Lewis Timothy A , Hartmann Constance B , McCoy Kathleen L
Published: January 2018

Gallium arsenide, a semiconductor utilized in the electronics industry, causes immunosuppression in animals. The chemical's effect on macrophages to process antigen for activating pigeon cytochrome-specific helper T cell hybridoma was investigated. Mice were administered 200 mg/kg gallium arsenide or vehicle intraperitoneally. Five-day exposure suppressed processing by splenic macrophages but augmented processing by thioglycollate-elicited and resident peritoneal macrophages. Cytochrome coupled to latex beads was targeted to phagolysosomes to examine processing in lysosomes. Cytochrome beads required phagocytosis for processing and were located in phagolysosomes. Gallium arsenide did not alter the phagocytic ability of macrophages. Peritoneal macrophages normally processed the targeted antigen, indicating that gallium arsenide influenced compartment(s) preceding lysosomes. However, the processing efficiency of exposed splenic macrophages depended on the size of particulate cytochrome, suggesting that processing varied in phagolysosomes of different sizes. Gallium arsenide impacted different intracellular compartments in these macrophages, perhaps contributing to systemic immunotoxicity and local inflammation caused by exposure.
Nonspecific and immune-specific up-regulation of cytokines in rabbit dermal tuberculous (BCG) lesions
Authors: Sugisaki Katsunori , Dannenberg Arthur M , Abe Yasuharu , Tsuruta Junji , Su Wei-Juin , Said Waheeda , Feng Lili , Yoshimura Teizo , Converse Paul J , Mounts Phoebe
Published: January 2018

To our knowledge, this is the first sequential study of cytokines in tissue sections of developing and healing tuberculous (BCG) lesions. In situ hybridization, immunohistochemical, and RT-PCR techniques were used. Cytokine mRNAs showed a biphasic pattern. The percentage of mononuclear cells (MN) containing IL-1β, TNF-α, MCP-1, and IL-8 mRNAs was highest in 1- to 3-day lesions, apparently because of the nonspecific inflammatory response caused by the tubercle bacilli in the BCG vaccine. At 5 days, this percentage was significantly reduced. With IFN-γ, the peak and trough were delayed by 2 days. By 9 days, the percentage of MN containing the mRNAs of all five cytokines had again increased and the rabbits had become tuberculin-positive. In general, MCP-1 and TNF-α proteins and the vascular adhesion molecules, ICAM, VCAM, and perhaps ELAM, peaked at about 3 days. Many mononuclear cells surrounding the central areas of solid and liquefied caseous necrosis contained chemokine IL-8 mRNA. IL-8 is known to attract PMN, and PMN were present nearby. In contrast, MN containing chemokine MCP-1 mRNA were present more peripherally in areas rich in macrophages and lymphocytes. The early nonspecific cytokine response seems to be an adjuvant effect of the mycobacteria in BCG vaccine in that it causes a rapid entry of macrophages, lymphocytes, granulocytes, and probably dendritic cells into local sites of antigen deposition. This effect should be considered in developing improved vaccines for the prevention of tuberculosis, because BCG vaccines producing a strong early cytokine response should be more immunogenic than BCG vaccines with similar antigens producing a weak response.
Signal transduction pathways activated by the IL-1 receptor family: ancient signaling machinery in mammals, insects, and plants
Authors: O'Neill Luke A J , Greene Catherine
Published: January 2018

Interleukin-1 (IL-1) is a central regulator of the immune and inflammatory responses. Recently, significant advances have been made in the area of IL-1 receptors and IL-1 signal transduction. A family of proteins has been described that share significant homology in their signaling domains with the Type I IL-1 receptor (IL-1RI). These include the IL-1 receptor accessory protein (IL-1AcP), which does not bind IL-1 but is essential for IL-1 signaling; a Drosophila protein Toll; a number of human Toll-like receptors (hTLRs); the putative IL-18/IL-1-γ receptor IL-1Rrp (IL-1 receptor-related protein); and a number of plant proteins. All appear to be involved in host responses to injury and infection. These homologies also extend to novel signaling proteins implicated in IL-1 action. Two IL-1 receptor-associated kinases, IRAK-1 and IRAK-2, which have homologs in Drosophila (Pelle) and plants (Pto), have been implicated in the activation of the transcription factor, nuclear factor κB (NF-κB). IRAK-1 has also been implicated in AP1 induction, Jun amino-terminal kinase (JNK) activation, and IL-2 induction. It recruits the adapter protein TRAF6 to the IL-1 receptor complex via an interaction with IL-1AcP. TRAF6 then relays the signal via NF-κB-inducing kinase (NIK) to two I-κB kinases (IKK-1 and -2), leading to NF-κB activation. Progress has also been made on other IL-1-responsive kinases, including JNK and p38 MAP kinase, with the latter having a role in multiple responses to IL-1. The remarkable conservation between diverse species indicates that the IL-1 system represents an ancient signaling machine critical for responses to environmental stresses and attack by pathogens.
The SOCS proteins: a new family of negative regulators of signal transduction
Authors: Nicholson Sandra E , Hilton Douglas J
Published: January 2018

The negative regulation of cytokine signaling, with the exception of the tyrosine phosphatases, is not widely understood. We recently identified a new family of negative regulators by retroviral expression of hematopoietic cDNA library in the monocytic leukemic cell line, M1. This was coupled with selection for cells that were no longer able to differentiate in response to interleukin-6. From this screen, SOCS-1 was cloned and was shown to arrest cytokine signaling by binding to and inhibiting the intrinsic enzymatic activity of the JAK family of protein tyrosine kinases. SOCS-1 expression is induced in response to a range of cytokines and as such is thought to form part of a classic negative feedback loop. The SOCS family of proteins is linked by the presence of a conserved carboxy-terminal domain termed the SOCS box and now encompasses five distinct protein groups on the basis of the structural elements found amino-terminal to the SOCS box: (1) those that contain SH2 domains, (2) those that contain WD-40 repeats, (3) ankyrin repeats, (4) SPRY domains, and (5) GTPase domains. As yet the function of the SOCS box remains unknown, but given the level of conservation within such diverse proteins, it is likely to have a broadly similar role in each.
γδ T cells present antigen to CD4+ αβ T cells
Authors: Collins Robert A , Werling Dirk , Duggan Sara E , Bland A Patricia , Parsons Keith R , Howard Christopher J
Published: January 2018

γδ and αβ TCR+ T cells share many properties and their interactions are likely to be coordinated and regulated. We provide evidence that cattle γδ T cells are able to present antigen to CD4+ T cells. To help elucidate their function γδ T cell lines were propagated for extensive characterization. Cells expressed high levels of MHC class II and production of costimulatory molecules as evidenced by the binding of a CTLA-4 fusion protein and synthesis of CD80 transcripts. These properties and the presence of a well-developed endosomal compartment indicated the cells might function as antigen-presenting cells. Resting CD4+ T cells from calves immunized with ovalbumin or respiratory syncytial virus-antigen proliferated in response to γδ T cells pulsed with antigen that appeared to be endocytosed via clathrin-coated pits or specific receptors.
Cloning and sequencing of the bovine flavocytochrome b subunit proteins, gp91-phox and p22-phox: comparison with other known flavocytochrome b sequences
Authors: Davis Angela R , Mascolo Patrice L , Bunger Peggy L , Sipes Karen M , Quinn Mark T
Published: January 2018

Neutrophils play an essential role in the cellular defense of the bovine mammary gland and compromised leukocyte function has been linked to the development of bovine mastitis. During mastitis, large numbers of leukocytes migrate into the mammary tissues where they become activated, resulting in the assembly of neutrophil membrane and cytosolic proteins to form a superoxide aniongenerating complex known as the NADPH oxidase. The key membrane-associated component of the NADPH oxidase is flavocytochrome b, which is a heterodimer of p22-phox and gp91-phox. Currently, only the human, porcine, murine, and rattus p22-phox and the human, porcine, and murine gp91-phox gene sequences are known. Because of the important role neutrophils play in bovine host defense, we carried out studies to clone, sequence, and analyze expression of bovine flavocytochrome b. Using polymerase chain reaction cloning techniques and a bovine spleen cDNA library we have cloned both of the bovine flavocytochrome b subunits, p22-phox and gp91-phox. Comparison of the bovine sequences with those of other species also revealed important information regarding key structural features of gp91-phox and p22-phox, including location of putative glycosylation sites. This study greatly contributes to our understanding of the potential functional sites of the flavocytochrome b subunits as well as providing information that can be used to study the role of neutrophils in bovine inflammatory diseases such as mastitis. J. Leukoc. Biol. 64: 114–123; 1998.
Characterization of a rat alveolar macrophage cell line that expresses a functional mannose receptor
Authors: Lane Kirk B , Egan Brian , Vick Sherell , Abdolrasulnia Rasul , Shepherd Virginia L
Published: January 2018

The mannose receptor is a single polypeptide transmembrane glycoprotein expressed on the surface of macrophages that binds and internalizes soluble and particulate ligands. Physiological ligands for this receptor are pathogens, such as mycobacteria, and extracellular acid hydrolases and peroxidases. Expression of the mannose receptor is tightly linked to the functional state of the macrophage: the receptor appears during differentiation, is increased by macrophage deactivating agents, and is reduced in the presence of macrophage activating agents. Studies of the mechanisms underlying these regulatory processes have been hampered by the lack of a stable cell line that expresses a functional and appropriately regulated mannose receptor. In this study we describe expression and modulation of the mannose receptor by the rat alveolar cell line NR8383. Similar amounts of the mannose receptor ligand horseradish peroxidase were internalized by both NR8383 cells and alveolar macrophages. In addition, NR8383 cells expressed immunoreactive mannose receptor protein and mannose receptor mRNA as detected by Northern analysis. Regulation studies showed that mannose receptor expression was regulated at the levels of activity, protein, and mRNA in NR8383 cells similarly to regulation in primary rat macrophages. In addition, NR8383 cells could be successfully transfected with a luciferase reporter gene, providing the transfectable, mannose receptor-positive macrophage cell line. These results support the hypothesis that NR8383 cells potentially represent the best current macrophage cell line for studying various aspects of macrophage function, and are particularly critical in studies of regulation of the mannose receptor, a key receptor in host defense and immune regulation. J. Leukoc. Biol. 64:345–350; 1998.
Granulocyte colony-stimulating factor activates a 72-kDa isoform of STAT3 in human neutrophils
Authors: Chakraborty Arup , Tweardy David J
Published: January 2018

Granulocyte colony-stimulating factor (G-CSF) signaling involves activation of STATs, proteins that serve the dual function of signal transduction and activation of transcription. We previously demonstrated that G-CSF activated a distinct Stat3-like protein in immature and mature normal myeloid cells, StatG. StatG in normal immature human myeloid cells, i.e. adult CD34+ bone marrow cells, was composed of Stat3β. This investigation was undertaken to determine the composition of StatG in mature normal human myeloid cells, i.e. polymorphonuclear neutrophilic granulocytes (PMN). These studies revealed that the major protein in extracts of PMN activated by G-CSF to bind the high-affinity serum-inducible element (hSIE) is a 72-kDa protein that cross-reacts with Stat3 monoclonal antibody, which we have designated Stat3γ. Stat3γ is derived from Stat3α by limited proteolysis and lacks the carboxyl-terminal portion of Stat3α. Because this region of Stat3α is involved in transcriptional activation, our findings suggest the possibility that Stat3γ may be transcriptionally inactive and may compete with Stat3α for Stat3 binding sites in these terminally differentiated myeloid cells. J. Leukoc. Biol. 64: 675–680; 1998.
Chemokines: signal lamps for trafficking of T and B cells for development and effector function
Authors: Kim Chang H , Broxmeyer Hal E
Published: January 2018

Chemokines can act as signal lamps for trafficking of lymphocytes at the important crossing points of lymphoid tissues. Lymphoid progenitors at different differentiation stages are differentially localized in primary lymphoid tissues and have differential responsiveness to thymic or bone marrow chemokines: SDF-1, CKβ-11/MIP-3β/ELC, SLC/6Ckine/Exodus2, MIP-1β, and TECK. Naive T cells and B cells circulate to secondary lymphoid tissues for possible activation. Chemokines, SDF-1, SLC/6Ckine/Exodus2, CKβ-11/MIP-3β/ELC, BLC/BCA-1, and DC-CK1/PARC, are expressed in the specialized microenvironments of secondary lymphoid tissues and regulate the migration of naive lymphocytes. Effector lymphocytes express a different set of chemokine receptors from naive lymphocytes. T helper (Th) 0 and 1 cells predominantly express CXCR3 and CCR5, whereas Th2 cells express CCR3, CCR4, and CCR8, which, with other factors such as expression patterns of adhesion molecules, likely determine the tissue- specific infiltration of effector lymphocytes. J. Leukoc. Biol. 65: 6–15; 1999.
Granulocyte-macrophage colony-stimulating factor modulates tapasin expression in human neutrophils
Authors: Ouakfaoui Souad El , Heitz Dominique , Paquin Robert , Beaulieu André D
Published: January 2018

Differential display-polymerase chain reaction (DD-PCR) was used to evaluate changes in mRNA expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) treated human neutrophils to better understand how this cytokine affects the functions of neutrophils at the molecular level. Although a variety of cDNA fragments were identified as modulated by GM-CSF with the use of DD-PCR, one fragment in particular, NGS-17 (neutrophil GM-CSF-stimulated fragment #17), was characterized. The NGS-17 fragment hybridized to a 3.8-kb mRNA that encodes for a protein of a predicted molecular mass of 47.6 kDa. After cloning and sequencing, this gene was found to code for the recently sequenced tapasin or TAP-A protein. Immunoprecipitation and immunoblotting studies using anti-tapasin antibodies showed that tapasin is expressed in neutrophils and is associated with the MHC class I-TAP complex. Moreover, tapasin expression was found to be induced by dimethyl sulfoxide and by retinoic acid in HL-60 cells. This is the first report on the expression of tapasin in human neutrophils. It provides novel information, at the molecular level, on how GM-CSF enhances the functions of these cells. J. Leukoc. Biol. 65: 205–210; 1999.
Flt3 signaling involves tyrosyl-phosphorylation of SHP-2 and SHIP and their association with Grb2 and Shc in Baf3/Flt3 cells
Authors: Zhang Shuli , Mantel Charlie , Broxmeyer Hal E
Published: January 2018

Flt3 ligand (FL) is an early-acting potent co-stimulatory cytokine that regulates proliferation and differentiation of a number of blood cell lineages. Its receptor Flt3/Flk2 belongs to class III receptor tyrosine kinases that also include the receptors for colony-stimulating factor 1, Steel factor, and platelet-derived growth factor. Using CSF-1 receptor/Flt3 chimeras, two groups have characterized some of the post-receptor signaling events and substrate specificity of murine Flt3 receptor. However, there are few studies on the signaling pathway through human Flt3. We examined human Flt3 signaling pathways in a murine IL-3-dependent hematopoietic cell line Baf3, which stably expresses full-length human Flt3 receptor. This subline proliferates in response to human FL. Like the chimeric murine Flt3, human Flt3 undergoes autophosphorylation, associates with Grb2, and leads to tyrosine phosphorylation of Shc on ligand binding. We found that SHP-2, but not SHP-1, is tyrosine-phosphorylated by FL stimulation. SHP-2 does not associate with Flt3, but binds directly to Grb2. SHIP is also tyrosine-phosphorylated and associates with Shc after FL simulation. We further examined the downstream signaling pathway. FL transiently activates MAP kinase. This activation could be blocked by PD98059, a specific MEK inhibitor. PD98059 also blocked cell proliferation in response to FL. These results demonstrate that SHP-2 and SHIP are important components in the human Flt3 signaling pathway and suggest that SHP-2 and SHIP, by forming complexes with adapter proteins Grb2 and Shc, may modulate MAP kinase activation, which may be necessary for the mitogenic signaling of Flt3. J. Leukoc. Biol. 65: 372–380; 1999.
Modulation of cellular annexin I in human leukocytes infiltrating DTH skin reactions
Authors: Perretti Mauro , Wheller Samantha K , Flower Roderick J , Wahid Smaira , Pitzalis Costantino
Published: January 2018

Based on our previous studies showing endogenous annexin I being depleted from migrated neutrophils (PMN) in vitro, we have tested whether the levels of this glucocorticoid-regulated protein in PMN and mononuclear cells (PBMC) were modified after adhesion to endothelial monolayers in vitro and extravasation into skin blisters in vivo. In vitro, annexin I levels were depleted more significantly (–70%) in post-adherent PMNs than in monocytes (–25%) and lymphocytes (–50%, only in the positive fraction). In vivo, a significant time-dependent increase (approximately threefold, P < 0.05) in cell-associated annexin I was measured in PBMCs recovered from the blisters, whereas no significant changes were detected in extravasated PMNs. This was associated with annexin I release in the blister fluids (∼35 ng/mL), whereas no detectable protein was found in matched-paired plasmas. In conclusion, we report for the first time an activation of the annexin I pathway during an ongoing experimental inflammatory response in humans, which is differently regulated between PMNs and PBMCs. J. Leukoc. Biol. 65: 583–589; 1999.
Assessment of chemokine receptor expression by human Th1 and Th2 cells in vitro and in vivo
Authors: Annunziato Francesco , Cosmi Lorenzo , Galli Grazia , Beltrame Chiara , Romagnani Paola , Manetti Roberto , Romagnani Sergio , Maggi Enrico
Published: January 2018

The preferential association of some chemokine receptors with human Th1 or Th2 cells has recently been reported. In this study, the expression of CCR3, CCR5, CXCR3, and CXCR4 were analyzed by flow cytometry in three distinct in vitro models of Th1/Th2 polarization, activated naive and memory T cells, and T-cell clones, in which the intracellular synthesis of interferon-γ (IFN-γ) and interleukin-4 (IL-4) and the surface expression of CD30 and LAG-3 were also assessed. Moreover, by using immunohistochemistry the in vivo expression of CCR3, CCR5, CXCR3, and CXCR4 was examined in the gut of patients suffering from Crohn's disease, a Th1-dominated disorder, and in the skin of patients suffering from systemic sclerosis, a Th2-dominated disorder. CCR5 and LAG-3 exhibited the same pathway of Th1 association, whereas CXCR3 did not discriminate between Th1- and Th2-dominated responses. On the other hand, CCR3 was found only occasionally in a small proportion of allergen-specific memory T cells with Th2/Th0 profile of cytokine production in vitro. However, it was neither seen in Th2-polarized activated naive T cells nor in established Th2 clones and could be detected in vivo only on non-T cells. Finally, whereas CXCR4 expression was not limited to Th2 cells in vivo, it was markedly up-regulated by IL-4 and down-regulated by IFN-γ in vitro. Thus, the results of this study confirm the existence of flexible programs of chemokine receptor expression during the development of Th1 and Th2 cells. However, caution is advised in interpreting these receptors as surrogate markers of a given type of effector response. J. Leukoc. Biol. 65: 691–699; 1999.
Regulation of neutrophil FcγRIIIb (CD16) surface expression following delayed apoptosis in response to GM-CSF and sodium butyrate
Authors: Moulding Dale A , Hart C Anthony , Edwards Steven W
Published: January 2018

When neutrophils undergo apoptosis, they lose expression of the surface receptor CD16 (FcγRIIIb). Thus levels of surface CD16 are good indicators of apoptotic or non-apoptotic neutrophils. Shedding of CD16 occurs via the activity of a metalloproteinase that cleaves the receptor from the plasma membrane. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and sodium butyrate both stimulate neutrophil gene expression, protect these cells from apoptosis, and maintain expression of surface CD16. In this report we have investigated whether these agents maintain surface expression of CD16 via (1) decreased shedding (2) increased mobilization of the internal pool of pre-formed CD16, or (3) via de novo biosynthesis of new receptor molecules. Although GM-CSF and sodium butyrate both preserved surface expression of CD16, GM-CSF actually accelerated the rate of shedding of this receptor. Maintenance of surface levels was achieved by substantial mobilization of the internal pool of CD16. Sodium butyrate, on the other hand, maintained surface expression without extensive store depletion via a mechanism that appeared to involve a decreased rate of shedding. In these experiments we could find no evidence for de novo biosynthesis of CD16 stimulated by either GM-CSF or sodium butyrate. These experiments indicate that multiple mechanisms exist for the maintenance of surface CD16 during rescue of neutrophils from apoptosis by different agents. J. Leukoc. Biol. 65: 875–882; 1999.
Functional studies on dendritic cells in the respiratory tract and related mucosal tissues
Authors: Holt P G , Stumbles P A , McWilliam A S
Published: January 2018

Recent reports indicate that mucosal tissues contain dendritic cell (DC) populations that exhibit phenotypic features distinct from those at more studied sites such as skin. In particular, mucosal DC populations display very rapid baseline turnover rates, which increase in response to local inflammatory stimuli. This property is likely to be central to the role of mucosal DC in surveillance of these front-line tissues for incoming microbial pathogens. As we discuss, it may also indirectly account for the “Th2 default,” which is the recognized hallmark of mucosal immune system in the steady state. J. Leukoc. Biol. 66: 272–275; 1999.
Differential responsiveness to constitutive vs. inducible chemokines of immature and mature mouse dendritic cells
Authors: Vecchi Annunciata , Massimiliano Lucia , Ramponi Simona , Luini Walter , Bernasconi Sergio , Bonecchi Raffaella , Allavena Paola , Parmentier Marc , Mantovani Alberto , Sozzani Silvano
Published: January 2018

Upon exposure to immune or inflammatory stimuli, dendritic cells (DC) migrate from peripheral tissues to lymphoid organs, where they present antigen. The molecular basis for the peculiar trafficking properties of DC is largely unknown. In this study, mouse DC were generated from CD34+ bone marrow precursors and cultured with granulocyte-macrophage-CSF and Flt3 ligand for 9 days. Chemokines active on immature DC include MIP1α, RANTES, MIP1β, MCP-1, MCP-3, and the constitutively expressed SDF1, MDC, and ELC. TNF-α-induced DC maturation caused reduction of migration to inducible chemokines (MIPIα, RANTES, MIP1β, MCP-1, and MCP-3) and increased migration to SDF1, MDC, and ELC. Similar results were obtained by CD40 ligation or culture in the presence of bacterial lipopolysaccharide. TNF-α down-regulated CC chemokine receptor (CCR)1, CCR2, and CCR5 and up-regulated CCR7 mRNA levels, in agreement with functional data. This study shows that selective responsiveness of mature and immature DC to inducible vs. constitutively produced chemokines can contribute to the regulated trafficking of DC. J. Leukoc. Biol. 66: 489–494; 1999.
Differential responses of human monocytes and macrophages to IL-4 and IL-13
Authors: Hart Prue H , Bonder Claudine S , Balogh Julianna , Dickensheets Harold L , Donnelly Raymond P , Finlay-Jones John J
Published: January 2018

The primary interleukin-4 (IL-4) receptor complex on monocytes (type I IL-4 receptor) includes the 140-kDa α chain (IL-4Rα) and the IL-2 receptor γ chain, γc, which heterodimerize for intracellular signaling, resulting in suppression of lipopolysaccharide (LPS)-inducible inflammatory mediator production. The activity of IL-13 on human monocytes is very similar to that of IL-4 because the predominant signaling chain (IL-4Rα) is common to both receptors. In fact, IL-4Rα with IL-13Rα1 is designated both as an IL-13 receptor and the type II IL-4 receptor. When the anti-inflammatory activities of IL-4 and IL-13 were investigated on synovial fluid macrophages and compared with the responses by monocytes isolated from the patients at the same time as joint drainage, the response profiles differed with some responses similar in the two cell populations, others reduced on the inflammatory cells. Similar differences were recorded in the response profiles to IL-4 and IL-13 by monocytes and monocytes cultured for 7 days in macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage CSF (GM-CSF) (monocyte-derived macrophages, MDMac). MDMac have reduced γc mRNA levels and reduced expression of the functional 64-kDa γc. There was a similar loss of IL-13Rα1 mRNA on monocyte differentiation. In turn, there was a significant reduction in the ability of IL-4 and IL-13 to activate STAT6. These findings suggest that different functional responses to IL-4 and IL-13 by human monocytes and macrophages may result from reduced expression of γc and IL-13Rα1. J. Leukoc. Biol. 66: 575–578; 1999.
Coexpression of binding sites for A(B) histo-blood group trisaccharides with galectin-3 and Lag antigen in human Langerhans cells
Authors: Smetana Karel , Holíková Zuzana , Klubal Radek , Bovin Nicolai V , Dvořánková Barbora , Bartůňková Jiřina , Liu Fu-Tong , Gabius Hans-Joachim
Published: January 2018

Galectin-3 is an immunomodulatory protein with binding capacity for various glycoconjugates including IgE. It has been shown to be produced by epidermal keratinocytes and is present on the surfaces of skin Langerhans cells (LC). Therefore, it may have a role in the pathogenesis of various skin diseases, such as atopic dermatitis. To study the expression of galectin-3 in LC, we used, in addition to specific antibodies, a panel of synthetic, carrier-immobilized, specific oligosaccharides of the A- and B-histo-blood group, which are recognized by this lectin. In the mean time, Birbeck granules were visualized with an anti-Lag antibody. The double labeling experiments showed a remarkable colocalization of signals for Lag antigen (Birbeck granules) and galectin-3, as well as the binding sites for A- and B-histo-blood group trisaccharides. The specificity of the oligosaccharide binding was demonstrated by the lack of binding by Lec, Led (H blood group antigen), and sLex, which are not recognized by galectin-3. These results suggest that galectin-3 is present in Birbeck granules, where it retains reactivity for its glycoligands. J. Leukoc. Biol. 66: 644–649; 1999.
Surface expression and rapid internalization of macrosialin (mouse CD68) on elicited mouse peritoneal macrophages
Authors: Kurushima H , Ramprasad M , Kondratenko N , Foster D M , Quehenberger O , Steinberg D
Published: January 2018

Macrosialin, the mouse homolog of human CD68, is a heavily glycosylated transmembrane protein found almost exclusively in macrophages. Its function remains uncertain. It has a high affinity for oxidized low-density lipoprotein (LDL) in ligand blots and antibodies against the human homolog, CD68, inhibit the binding of oxidized LDL to a human monocyte-derived cell line (THP-1). However, there is still controversy as to whether macrosialin, found predominantly in late endo-somes, is expressed at all on the plasma membrane. The present studies, done in thioglycollate-elicited peritoneal macrophages, confirm that macrosialin is predominantly intracellular but show clearly that 10–15% of it is expressed on the cell surface. Exchange with intracellular pools occurs at an extremely high rate. The results are compatible with a surface function, including internalization of bound ligands or adhesion to surfaces. J. Leukoc. Biol. 67: 104–108; 2000.
Extracellular matrix moieties, cytokines, and enzymes: dynamic effects on immune cell behavior and inflammation
Authors: Vaday Gayle G , Lider Ofer
Published: January 2018

Tissue injury caused by infection or physical damage evokes inflammatory reactions and events that are necessary for regaining homeostasis. Central to these events is the translocation of leukocytes, including monocytes, neutrophils, and T lymphocytes, from the vascular system, through endothelium, and into the extracellular matrix (ECM) surrounding the injured tissue. This transition from the vasculature into the site of inflammation elicits remarkable changes in leukocyte behavior as cells adhere to and migrate across ECM before carrying out their effector functions. Growing evidence suggests that, through its interactions with cytokines and degradative enzymes, the ECM microenvironment has a specialized role in providing intrinsic signals for coordinating leukocyte actions. Recent advances also reveal that enzymatic modifications to ECM moieties and cytokines induce distinctive cellular responses, and are likely part of the mechanism regulating the perpetuation or arrest of inflammation. This article reviews the findings that have elucidated the dynamic relationships among these factors and how they communicate with immune cells during inflammation. J. Leukoc. Biol. 67: 149–159; 2000.
Reduced brain edema after traumatic brain injury in mice deficient in P-selectin and intercellular adhesion molecule-1
Authors: Whalen Michael J , Carlos Timothy M , Dixon C Edward , Robichaud Paul , Clark Robert S B , Marion Donald W , Kochanek Patrick M
Published: January 2018

Platelet (P-) selectin and intercellular adhesion molecule-1 (ICAM-1) mediate accumulation of neutrophils in brain. However, the mechanisms regulating neutrophil accumulation and damage after traumatic brain injury (TBI) are poorly defined. We hypothesized that mice deficient in both P-selectin and ICAM-1 (-/–) would have decreased brain neutrophil accumulation and edema, and improved functional and histopathological outcome after TBI compared with wild-type (+/+). In Protocol I, neutrophils and brain water content were quantified at 24 h after TBI. No difference in brain neutrophil accumulation was observed between groups; however, brain edema was decreased in dual P-selectin and ICAM-1 –/– (P < 0.05 vs. +/+ mice). In Protocol II, after TBI, tests of motor and memory function and histopathology were assessed over 21 days. No difference in motor or memory function or histopathological damage was observed between +/+ and –/– mice. A role for adhesion molecules in the pathogenesis of brain edema independent of leukocyte accumulation in brain is suggested. J. Leukoc. Biol. 67: 160–168; 2000.
Homing and adhesion molecules in autoimmune gastritis
Authors: Barrett Simon P , Riordon Amy , Toh Ban Hock , Gleeson Paul A , van Driel Ian R
Published: January 2018

The pathogenesis of autoimmune gastritis is the result of lymphocyte infiltration of the gastric mucosa, however, the events leading to the selective extravasation of autoreactive lymphocytes are unclear. Here we have examined the expression of adhesion molecules in the gastric mucosa of BALB/c mice with neonatal thymectomy-induced gastritis. The overall area of vascular endothelium was not significantly different between gastritic and non-gastritic mice. However, a significant increase in the area of mucosal endothelium expressing MAdCAM-1 in gastritic mice was observed. Treatment of neonatally thymectomized BALB/c mice with a MAdCAM-1 specific monoclonal antibody (MECA 367) reduced the incidence of autoimmune gastritis from 80 to 26%. Treatment with a monoclonal antibody (R1-2) directed to the MAdCAM-1 ligand, α44β7, also resulted in a reduction in the incidence of gastritis to 40%. These findings identify the α4β7/MAdCAM-I interaction as a pivotal event in the initiation of autoimmune gastritis. J. Leukoc. Biol. 67: 169–173; 2000.