bluuebunny/crossref_metadata_2025 huggingface dataset:
ICAM-1 mediates leukocyte-endothelium adhesive interactions in the reversed passive Arthus reaction
Authors: Smith Robert J , Chosay John G , Dunn Colin J , Manning Anthony M , Justen James M
Published: January 2018

A murine anti-rat intercellular adhesion molecule 1 (ICAM-1) monoclonal antibody (mAb), 1A29, was used to investigate the importance of blood leukocyte-associated β2-integrin (CD11/CD18)/vascular endothelmm-associated ICAM-1 adhesive interactions in the reversed passive Arthus reaction (RPAR) in rats. An Arthus pleurisy reaction (4 h) was employed in these studies because it permits the accurate quantitation of polymorphonuclear neutrophil (PMN) influx into the pleural space and fluid accumulation. 1A29, which localized within Arthus lung lesions, caused a dose-dependent (0.5–2.0 mg/kg, i.v.) inhibition of PMN influx (19–56%) and exudate volume (9–55%) in the Arthus pleurisy reaction. P7 (2 mg/kg, i.V.), a murine anti-human P-selectin mAb used as an isotype-matched control tor 1A29, did not localize at the lung lesion site and was inactive. Immunohisto-chemical analysis of lung tissue from 1A29-treated rats demonstrated increased granulocyte accumulation in the alveolar capillaries compared with more extensive granulocyte emigration into the lung tissue and pleural space in P7-treated rats and Arthus control rats; however, quantitative image analysis revealed increased numbers of lung granulocytes in 1A29-treated rats compared with controls. Neither ICAM-1 mRNA nor expression, assessed by immunocytochemistry, was increased above control levels in rats during the pleural Arthus reaction. Neutropenia was not observed in either 1A29- or P7-treated rats.
Protein tyrosine kinases in activation signal of human basophils through the immunoglobulin E receptor type I
Authors: Benhamou Marc , Feuillard Jean , Lortholary Olivier , Bourgeois Clotilda , Michel Laurence , LeGoff Liliane , Michel Ariane , Mencia-Huerta Jean-Michel , Lejeune Françoise , Casassus Philippe , Debré Patrice , Arock Michel
Published: January 2018

Human basophils activated through high-affinity immunoglobulin E (IgE) receptors (FcRI) are involved in the late phase of the allergic reaction. To investigate the possible involvement of protein-tyrosine kinases in this activation we used human acute basophilic leukemia (ABL) cells in culture as well as a pure population of normal basophils in vitro-derived from human bone marrow precursor cells (HBMB). ABL cells were 50–80% basophils at various stages of maturation as assessed by staining, morphology, ultrastructure, and flow cytometry analysis, and only basophils in ABL cells expressed FcRI. Aggregation of FcRI by IgE and anti-IgE, IgE and antigen, or anti-FcRI monoclonal antibodies on ABL cells or on HBMB, led to increased tyrosine phosphorylation of 120-, 100-, 80-, 72-, 50- to 65-, and 38-kDa substrates. Tyrosine phosphorylations in ABL cells were in basophils because 1) they were detected after a 5-s stimulation, 2) they were observed under conditions where mediator release is minimal, i.e., in the absence of extracellular calcium, 3) hapten addition during antigen stimulation resulted in almost total disappearance of tyrosine phosphorylations within 30 s. There was correlation between histamine release and tyrosine phosphorylation in anti-IgE dose-responses and in dose-responses of the tyrosine kinase inhibitor genistein. The tyrosine kinase p72syk was detected in the cells. Stimulation of ABL cells for 1 min resulted in extracellular calcium-independent tyrosine phosphorylation and activation of p72syk Therefore, tyrosine kinases are involved in the early steps of human FcRI signaling in basophils. Tyrosine kinases and their substrates could represent new potential therapeutic targets to prevent the development of the allergic reaction. 1996.
Alveolar macrophage kinetics and multinucleated giant cell formation after lung injury
Authors: Prieditis H , Adamson I Y R
Published: January 2018

Multinucleated giant cells (MGC) are a prominent feature of some chronic inflammatory states in the lung. These cells are formed by macrophage fusion, but how this process relates to the kinetics of alveolar macrophage (AM) production and proliferation is not clear. In this serial study, we compare AM kinetics and MGC formation after instilling carbon, silica, asbestos, bleomycin, and saline into the lungs of mice. Animals were killed up to 16 weeks later with [3H]thymidine injected 1 h before death. Counts of AM and MGC were carried out after bronchoalveolar lavage, and cell labeling was assessed by autoradiography. All test substances induced an inflammatory response with equal AM numbers recovered up to 2 weeks. Subsequently, the number returned to normal after carbon but remained elevated in the other groups. After carbon the lung structure was normal, there was no increase in AM label, and no MGC formed. Bleomycin-injected lungs progressed to fibrosis with only a brief, small increase in AM labeling and no MGC formation. After silica, and particularly asbestos, the lungs showed fibrosis, and many granulomas with large MGC were seen. Lavaged AM from these lungs showed a significant increase in DNA synthesis after 2 weeks, followed by higher numbers of MGC, none of which were labeled. Labeled AM tended to be free of particles, whereas MGC after 4 weeks contained many particles. The results indicate a relationship between AM proliferation and fusion, whereby AM growth appears to be prerequisite for cell fusion and MGC formation as a feature of granulomatous disease.
Estrogen regulation of JE/MCP-1 mRNA expression in fibroblasts
Authors: Kovacs E J , Faunce D E , Ramer-Quinn D S , Mott F J , Dy P -W W , Frazier-Jessen M R
Published: January 2018

We have recently demonstrated that 17β-estradiol (E2) inhibits peritoneal adhesion formation. Because macrophages play a central role in inflammation and wound healing, we chose to investigate whether the E2 could inhibit the expression of JE, the murine monocyte chemoattractant protein-1 (MCP-1). To accomplish this, murine fibroblasts were cultured with physiological concentrations of E2 (3–300 pg/ml) with or without inducers of JE/MCP-1 mRNA expression. Untreated cells failed to express the message, but, following stimulation, a marked increase in JE/MCP-1 mRNA expression was observed. At 10–30 pg/ml, E2 had no effect on JE/MCP-1 mRNA expression in stimulated fibroblasts. In contrast, lower and higher doses of E2 inhibited the expression of JE/MCP-1 mRNA in stimulated fibroblasts. Treatment with tamoxifen reversed the E2-inhibition of expression of the message. These data demonstrate that JE/MCP-1 mRNA expression is controlled, in part, by estrogen and suggest that macrophage recruitment may be affected by circulating levels of E2.
Transcriptional regulation of LDL receptor-related protein by IFN-γ and the antagonistic activity of TGF-β1 in the RAW 264.7 macrophage-like cell line
Authors: Hussaini Isa M , LaMarre Jonathan , Lysiak Jeffrey J , Karns Larry R , VandenBerg Scott R , Gonias Steven L
Published: January 2018

Low density lipoprotein receptor-related protein (LRP) is a major receptor for multiple ligands, including chylomicron and VLDL remnants, bacterial toxins, viruses, proteinases, lipoprotein lipase, and activated α2-macroglobulin (α2M). In this study, we used Northern blot analyses and nuclear run-on experiments to demonstrate that interferon-γ (IFN-γ) causes a concentration-dependent decrease in steady-state LRP mRNA expression and gene transcription rate in RAW 264.7 cells. IFN-γ also markedly increased expression of inducible nitric oxide synthase (NOS), as expected; however, the increase in nitric oxide was not responsible for the down-regulation of LRP expression since the NOS inhibitor, NG-monomethyl-l-arginine, did not preserve LRP expression in IFN-γ-treated cells. Trans-forming growth factor-β1 (TGF-β1; 2.5 ng/mL) had no independent effect on LRP expression and did not modify the response to IFN-γ when the two cytokines were added simultaneously to cultures. When TGF-β1 was added 24 h prior to IFN-γ, the extent of LRP down-regulation was significantly reduced. Specific binding of the LRP ligand, activated 125I-α2M, was decreased by 76 ± 5% in cells treated with 100 U/mL IFN-γ, but only by 45 ± 7% in cells treated with 100 U/mL IFN-γ after TGF-β1-pretreatment. The antagonistic activity of TGF-β1 on the IFN-γ response in RAW 264.7 cells did not result from a change in LRP mRNA stability or IFN-γ receptor expression, as determined by Northern blot analyses 125I-IFN-γ binding experiments. The studies presented here suggest that the balance between IFN-γ and TGF-β1 may be critical in determining LRP expression at sites of infection and inflammation.
Regulation of leukocyte adhesion and signaling in inflammation and disease
Authors: Wahl S M , Feldman G M , McCarthy J B
Published: January 2018

Cell adhesion molecules provide the foundation for cell communication, trafficking, and immune surveillance central to host defense. These adhesion molecules which include selecting, integrins and members of the Ig superfamily, provide a recognition system between leukocytes, endothelial cells and matrix molecules. Leukocyte-endothelial interactions initiate recruitment at sites of injury, infection and inflammation. Cell-cell and cell-matrix interactions also influence leukocyte phenotype and function. Dysregulation of these adhesion and signal transduction pathways can contribute to continued recruitment and persistent leukocyte activation with unresolved inflammation. Based on the pivotal role adhesive interactions play, the adhesion molecules provide potential targets for intervention. Selected synthetic fibronectin peptides, which inhibit leukocyte integrin binding and signal transduction in vitro, block recruitment and activation to limit inflammation in vivo.
Human recombinant monocyte chemotactic protein and other c-c chemokines bind and induce directional migration of dendritic cells in vitro
Authors: Xu Luo Ling , Warren M Kim , Rose Wendy L , Gong Wanghua , Wang Ji Ming
Published: January 2018

Because dendritic cells (DC) are the most potent antigen-presenting cells involved in many pathophysiological responses, we investigated the effect of chemokines on the migration of these cells in an effort to determine whether chemokines may contribute to the initiation of immune responses. CD34+ progenitor cells isolated from umbilical cord blood were grown in suspension cultures with cytokines and expanded 50- to 100-fold. A variable proportion of the cells expressed markers consistent with DC. The proportion of CD1a+ DC was increased when the cells were cultured with interleukin-4 (IL-4). These cells expressed specific binding sites for C-C and C-X-C chemokines. Cells cultured with or without IL-4 had similar binding profiles. All C-C chemokines tested, including monocyte chemotactic protein (MCP)-1, MCP-2, MCP-3, macrophage inflammatory protein-1α (MIP1α), MIP-1β, and RAN-TES, induced migration of DC-enriched cells cultured with or without IL-4 with MCP-3 being the most potent chemoattractant. Phenotypic analysis of cell migrating in response to C-C chemokines showed that CD1a+ cells were indeed attracted across the polycarbonate filters, and there was no preferential attraction of contaminating CD14+ monocytes by C-C chemokines. DC-enriched cells also expressed specific binding sites for IL-8 and NAP2, which failed to induce cell migration. Our results suggest that C-C chemokines may participate in the recruitment of DC to amplify host defense.
Integrin signaling in leukocytes: lessons from the α6β1 integrin
Authors: Wei Jueyang , Shaw Leslie M , Mercurio Arthur M
Published: January 2018

The adhesive interactions of leukocytes with basement membrane components and other extracellular matrix (ECM) proteins are mediated largely by the integrin family of receptors. These interactions can be regulated by various effector molecules including chemokines, growth factors, and other cell surface proteins by a mechanism termed inside-out signaling of integrin function. On engagement by their ligands, integrins activate a wide range of signaling pathways that regulate a broad array of leukocyte functions such as chemotaxis, cytokine responsiveness, phagocytosis, and gene expression. This review highlights recent advances in the understanding of integrin signaling in leukocytes with an emphasis on our own work on the α6β1 integrin, the major laminin receptor expressed by these cells.
The α4β1 integrin can mediate leukocyte adhesion to casein and denatured protein substrates
Authors: Davis George E , Thomas J Scott , Madden Steven
Published: January 2018

An understanding of the binding specificity of leukocyte integrins is important to determine the range of ligands that interact with these receptors during inflammatory processes. In this study we show that the α4β1 integrin can interact with casein and denatured albumin and promote leukocyte adhesion through these interactions. This was demonstrated with the use of blocking antibodies directed to α4β1 and peptide adhesion competitors containing the α4β1 binding tripeptide, Leu-Asp-Val (LDV). Consistent with this data, the adhesion is completely divalent cation-dependent and is stimulated by known activators of leukocyte integrin function, namely phorbol ester and the β1 integrin activating antibody, 8A2. It is interesting to note that neither bovine α-casein or human albumin contain an LDV site (present in the CS-1 site of alternatively spliced fibronectin) or an IDS site (present in VCAM-1) yet they promote adhesion through this integrin. Furthermore, α4β1 directly binds to Sepharose columns containing casein, casein fragments, or denatured albumin but does not bind columns containing native albumin. These data suggest that the binding specificity for the α4β1 integrin is considerably broader than previously realized. This work has implications for how subsets of leukocytes may interact with damaged proteins during tissue injury and inflammation.
A cytosolic calcium transient is not necessary for degranulation or oxidative burst in immune complex-stimulated neutrophils
Authors: Seetoo Kurt F , Schonhorn Jeremy E , Gewirtz Andrew T , Zhou Ming Jie , McMenamin Mary E , Delva Luisette , Simons Elizabeth R
Published: January 2018

Receptor-mediated activation of neutrophils (PMN) initiates possibly interdependent events, including a rapid transient increase in [Ca2+]i, implicated as a second messenger. To investigate whether this transient is required for eventual degranulation, PMN were incubated with an intracellular Ca2+ chelator (BAPTA), then exposed to chemotactic peptide [N-formyl-methionyl-leucyl-phenylalanine (fMLP)] with or without cytochalasin B (CB) or to high-valency immune complexes (HIC); δ[Ca2+]i, δpHi, oxidative burst, and elastase release were then evaluated (plus or minus EGTA 15 s before stimulation) after 2 and 15 min incubation in 0.9 mM Ca2+. With either fMLP plus CB or HIC stimulation, BAPTA-treated cells were unable to achieve a Ca2+ transient with a 2-min incubation, whereas a 15-min incubation allowed the BAPTA-treated cells to recover a portion of the δ[Ca2+]i. Even though BAPTA-treated cells were unable to mount a δ[Ca2+]i at 2 min, HIC-stimulated BAPTA-treated cells were able to elicit an oxidative burst (33% of control) and degranulation (67% of control). Therefore, we conclude that δ[Ca2+]i modulates but is not required for oxidative burst or degranulation.
Effects of inhibitors of inflammatory mediators and cytokines on eosinophil and neutrophil accumulation induced by Mycobacterium bovis bacillus Calmette-Guérinin mouse pleurisy
Authors: Menezes-de-Lima-Júnior Octávio , Werneck-Barroso Eduardo , Cordeiro Renato S B , das Graças Maria , Henriques M O
Published: January 2018

In this work we characterize the Mycobacterium bovis bacillus Calmette-Guérin(BCC) -induced pleurisy and investigate the role of chemical mediators and cytokines in BCG-induced granulocyte accumulation at 24 h. Intrathoracic injection of BCG in C57B1/6 mice induces a biphasic inflammatory reaction with intense leukocyte accumulation at 24 h and 15 days. Neutrophils were observed in the pleural cavity at 4-24 h, mononuclear cells and eosinophils after 24 h. A new wave of mononuclear cells and neutrophils were observed after 15 days. Pretreatments with dexamethasone, BW 755C, BW A4C, WEB 2170, L-NAME, and monoclonal antibody (mAb) anti-interleukin-5 (IL-5; TRFK-5) had inhibited the eosinophil accumulation. On the other hand, only the pretreatments with dexamethasone, L-NAME, or mAb antitumor necrosis factor a (TNF-α; MP6-XT3) had inhibited the neutrophil influx. These results suggest the involvement of leukotrienes, platelet-activating factor, nitric oxide, and IL-5 in the eosinophil accumulation, and a role for nitric oxide and TNF-α in the neutrophil influx induced by BCG.
Glutathione peroxidase activity and mRNA expression in eosinophils and neutrophils of asthmatic and non-asthmatic subjects
Authors: Misso Neil L A , Peroni Darryl J , Watkins D Neil , Stewart Geoffrey A , Thompson Philip J
Published: January 2018

Asthma has been reported to be associated with a reduction in the activity of glutathione peroxidase (GSH-Px), an important antioxidant enzyme. However, the expression of GSH-Px enzyme activity has not previously been investigated in human eosinophils, which are important inflammatory cells involved in asthma. Reverse transcriptase-polymerase chain reaction and Southern blotting demonstrated that eosinophils express GSH-Px mRNA and the relative expression of GSH-Px was greater in eosinophils than in neutrophils for both asthmatic and non-asthmatic subjects. The presence of GSH-Px protein in eosinophil and neutrophil lysates was confirmed by size exclusion chromatography and by Western blotting. GSH-Px enzyme activity as measured by a spectrophotometric assay was greater in eosinophil (48.4 ± 1.6 μmol NADPH oxidized · min–1 · g–1 protein) than in neutrophil lysates (18.1 ± 0.4, n = 24, P < 0.0001). GSH-Px activities of eosinophils and neutrophils from asthmatic subjects did not differ from those of non-asthmatic subjects. Eosinophil GSH-Px activity was correlated with peripheral blood eosinophil count only in asthmatic subjects (rs = 0.59, n = 12, P = 0.04). Increased GSH-Px expression in eosinophils compared with neutrophils of asthmatic patients may provide antioxidant protection against the greater amounts of reactive oxygen species generated by these cells and may enhance the survival of eosinophils at sites of inflammation in asthma.
Modulation of cell adhesion molecules on human endothelial cells by eosinophil-derived mediators
Authors: Molet S , Gosset P , Vanhee D , Tillie-Leblond I , Wallaert B , Capron M , Tonnel A-B
Published: January 2018

Mechanisms that allow a selective eosinophil emigration in different eosinophilic lung diseases remain poorly understood. In this study, we tested the hypothesis that eosinophils might participate in their own recruitment, particularly through adhesion molecule expression on human endothelial cells (EC). Blood eosinophils from donors with blood eosinophilia were purified and maintained in culture medium for 1 and 18 h. The expression of ICAM-1, E-selectin, and VCAM-1 on human umbilical vein endothelial cells (HUVEC) was evaluated by ELISA and flow cytometry analysis after addition of eosinophil supernatants. Eosinophil supernatants collected after 1 h induced a weak increase of CAM expression on HUVEC. In contrast, supernatants from eosinophils cultured for 18 h considerably amplified ICAM-1, E-selectin, and VCAM-1 expression on the surface of EC. These levels of CAM expression (in optical density determined by ELISA) were about two- or threefold more important than those obtained with eosinophil supernatants collected after a 1-h culture. The characterization of the implicated molecules showed that anti-IL-1β antibodies significantly inhibited ICAM-1, E-selectin, and VCAM-1 expression, whereas anti-TNF-α antibodies only induced a moderate inhibition. Our data support the hypothesis that eosinophils, through the release of at least IL-1β and TNF-α, might participate in the amplification of the inflammatory reaction by activating the vascular endothelium.
HIV-1 induces human monocyte-derived macrophages to produce C3 and to fix C3 on their surface
Authors: Bajtay Zsuzsa , Kacani Laco , Erdei Anna , Dierich Manfred P
Published: January 2018

Complement components, particularly C3, are known to be involved in the pathogenesis of AIDS and macrophages may serve as a source of C3 at sites of infection. We investigated whether the interaction between HIV-1 and monocytes has any effect on C3 production by the cells. Monocytes isolated from the blood of healthy volunteers were incubated with monocytotropic and T lymphocytotropic HIV-1 strains or with recombinant gp160 and cultured in serum-free medium up to 7 days. Supernatants were tested for secreted C3 by enzyme-linked immunosorbent assay. Our data show that monocytes cultured with either the monocytotropic or the T lymphocytotropic HIV-1 strains produce C3 in large amounts. The effect of both viruses is dose dependent and the amount of C3 induced by HIV was up to 20-fold higher than in the control samples. C3 production was also enhanced by gp160, the envelope protein of the virus. Secretion of IL-6 by the cells was also measured and found to be elevated up to threefold as a consequence of the interaction with the virus. HIV-1-activated monocyte-derived macrophages acquired the capacity to cleave exogenous C3 and to fix generated C3 fragments on their cell membrane.
Urinary levels of chemokines (MCAF/MCP-1, IL-8) reflect distinct disease activities and phases of human IgA nephropathy
Authors: Yokoyama Hitoshi , Wada Takashi , Furuichi Kengo , Segawa Chikako , Shimizu Miho , Kobayashi Ken-ichi , Su Shao-bo , Mukaida Naofumi , Matsushima Kouji
Published: January 2018

Leukocytes have been implicated to be involved in the pathogenesis of IgA nephropathy (IgAN). To clarify the precise molecular mechanism of recruitment and activation of leukocytes in the subgroups of IgAN, latent, acute, and chronic types, we studied monocyte chemotactic and activating factor (MCAF/MCP-1) and interleukin (IL)-8 in urines and renal expression of these cytokines. Urinary MCAF levels were significantly higher in chronic type, and were correlated with pathological progressive factors such as mesangial proliferation and interstitial cellular infiltration associated with CD68-positive macrophage. On the other hand, urinary IL-8 elevated only in acute type and were correlated with glomerular endocapillary proliferation and the degree of hematuria. In immunohistochemical study, IL-8 was mainly observed in glomeruli, otherwise MCAF in vascular endothelial cells, tubular epithelial cells, and infiltrated mononuclear cells in the interstitial lesions. These observations demonstrated that MCAF and IL-8 were differentially expressed in kidneys with IgAN, and their subtypes, and suggest that chemokines may be involved in the pathogenesis of IgAN at distinct phases or pathological lesions, possibly through the recruitment and activation of a distinct type of leukocyte.
Signal transduction by immunoglobulin Fc receptors
Authors: Sánchez-Mejorada Gabriela , Rosales Carlos
Published: January 2018

Receptors for the Fc portion of immunoglobulin molecules (FcR) present on leukocyte cell membranes mediate a large number of cellular responses that are very important in host defense. Cross-linking of FcR by immune complexes leads to functions such as phagocytosis, cell cytotoxicity, production and secretion of inflammatory mediators, and modulation of the immune response. Molecular characterization of FcRs indicates the existence of several types of these receptors, which seem to be redundant in their cell distribution and function. There is a great deal of interest in understanding how these various receptors signal the cell to respond in different ways during inflammation and the immune response. Previous studies indicate that FcR signaling shares elements with the T and B cell antigen receptors. Signaling is initiated in all of them by activation of tyrosine kinases of the Src and ZAP-70 families. Subsequent events, which vary depending on the cell type and receptor involved, include activation of other enzymes such as phospholipase Cγ1, phosphatidylinositol-3-kinase, and mitogen-activated protein kinase. Several recent lines of research, including studies of phagocytosis by FcR-transfected cells, antibody-dependent cytotoxicity by natural killer cells, mast cell degranulation, and FcR-deficient mice, have given us new insights on the signal transduction pathways activated by FcRs. This review describes the advances in these areas and presents a general model for FcR-mediated signaling.
Arterial and venular endothelial cell costimulation of cytokine secretion by human T cell clones
Authors: Johnson David R , Hauser Ingeborg A , Voll Reinhard E , Emmrich Frank
Published: January 2018

Vascular endothelial cell (EC) costimulation of cytokine secretion by T lymphocytes may be important in inflammation and allograft rejection. Venous and arterial iliac endothelial cells (VIEC, AIEC) both costimulate interleukin-2 (IL-2) production by peripheral blood lymphocytes (PBL) or T cell clones stimulated with phytohemagglutinin (PHA). Interferon-γ (IFN-γ) production is costimulated in a subset of clones but IL-4 is not. Surprisingly, two T cell clones were reciprocally better costimulated by VIEC or AIEC. EC activation by pretreatment with tumor necrosis factor α (TNF-α) does not increase T cell costimulation despite large increases in EC cell adhesion molecule expression. Neither VIEC nor AIEC express CTLA4-binding molecules and costimulation is blocked by cyclosporin A, suggesting that CD28 is not involved in EC costimulation of T cells. These data suggest that adult vascular EC costimulate production of IL-2 and IFN-γ but not IL-4 by mature T cells, that EC costimulation is not increased in inflamed tissues, and that different EC optimally costimulate particular T cells. These findings have implications for the nature of the costimulatory signal(s) provided by EC and may be important in understanding vasculitis or atherosclerosis.
Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection
Authors: Murayama Tsugiya , Mukaida Naofumi , Khabar Khalid S A , Matsushima Kouji
Published: January 2018

The observations that several types of viruses induced interleukin (IL)-8 production prompted us to investigate the interrelationship between IL-8 and cytomegalovirus (CMV) infection. CMV infection caused IL-8 production in a human monocytic cell line, THP-1, in dose- and time-dependent manners. Moreover, CMV induced IL-8 gene expression by concurrently activating transcription factors, NF-κB and AP-1. Furthermore, CMV infection of human fibroblast cell lines increased gene expression of a specific receptor for IL-8, CXCR1. IL-8 in turn enhanced CMV replication in a human embryonic fibroblast, MRC-5, in dose- and time-dependent manners. Augmented replication eventually culminated in the increased production of infectious CMV virions. Moreover, IL-8 can attenuate the antiviral activity of interferon (IFN), particularly that of α-type against picornaviruses such as encephalomyocarditis virus and poliovirus. The inhibitory effects were associated with reduced 2′,5′-A oligoadenylate synthetase activity. These results would imply that CMV can induce IL-8, which can augment CMV replication directly and indirectly by counteracting antiviral activity of IFN. J. Leukoc. Biol. 64: 62–67; 1998.
Altered levels of urokinase on monocytes and in serum of children with AIDS; effects on lymphocyte activation and surface marker expression
Authors: Murali Rama , Wolfe Joshua H , Erber Rebecca , Chice Seto M , Murali M R , Durkin Helen G , Zach Petr , Auci Dominick L
Published: January 2018

Urokinase (UK) type plasminogen activator is a serine protease produced by activated human monocytes. Despite the well-documented roles played by UK in cell-mediated immunity in healthy humans, the roles played by UK in the derangements of cell-mediated immune responses observed in HIV disease remain largely undefined. In these studies the numbers of peripheral blood lymphocytes and monocytes bearing surface UK (UK+) as well as serum levels of UK (flow microfluorimetry and ELISA, respectively) were determined in children with AIDS and in healthy HIV-negative children. The effects of exogenous UK on lymphocyte activation (cell cycle analysis using living cells) and surface marker (CD3, CD4, CD8, and CD19) expression (flow microfluorimetry using fixed cells) were also studied. Data are expressed as percent total cells. Numbers of UK+ lymphocytes in children with AIDS were similar to those observed in healthy children. In contrast, numbers of UK+ peripheral blood monocytes were dramatically decreased (>70%) in the children with AIDS. However, serum levels of UK were increased (nearly threefold) in these children. When lymphocytes from these children were cultured with soluble UK, numbers of cells in S phase of cell cycle appeared suppressed. Incubation of fixed lymphocytes from either a child with AIDS or from a healthy child with exogenous UK appeared to increase numbers of cells expressing CD3. Incubation with UK had no effect on expression of any other surface marker (CD4, CD8, or CD19) using cells from the child with AIDS. In contrast, incubation with UK appeared to decrease (fivefold) numbers of cells expressing CD19 and increase numbers of cells expressing CD4 and CD8 only when fixed lymphocytes from a healthy HIV-negative child were used. The results suggest important roles for UK in regulation of lymphocyte surface markers in general and in CD3- and CD19-dependent lymphocyte activation pathways specifically. Furthermore, these studies add to a widening body of evidence implicating UK dysregulation in the pathogenesis of HIV disease and may point to pharmacological opportunities involving UK to delay or prevent progression of HIV infection into full-blown AIDS. J. Leukoc. Biol. 64: 198–202; 1998.
SB202190, a selective inhibitor of p38 mitogen-activated protein kinase, is a powerful regulator of LPS-induced mRNAs in monocytes
Authors: Manthey Carl L , Wang Shen-Wu , Kinney Stephen D , Yao Zhengbin
Published: January 2018

Inhibitors of p38 mitogen-activated protein kinase (p38) have been reported to block tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) production in monocytes at the level of mRNA translation. Yet, several studies document that p38 can phosphorylate and activate specific transcription factors. Thus, to understand better the role of p38 during monocyte activation, we sought to determine the extent to which p38 is required for lipopolysaccharide (LPS)-induced gene expression. For this, differential mRNA display was used to identify LPS-induced genes whose expression was blocked by SB202190, a specific inhibitor of p38. A partial screen identified 10 genes in monoyctes induced 4- to 74-fold by LPS. Of these, genes encoding interferon-induced gene 15, neuroleukin, radiation-inducible immediate-early gene-1, A20, IL-1β, and superoxide dismutase were suppressed >50% by SB202190. LPS-induced gene activation was not blocked by cycloheximide, indicating that synthesis of intermediate proteins was not required. SB202190 blocked gene induction by 50% when present between 41 and 123 nM, consistent with the potency of this compound as a p38 inhibitor. Furthermore, the ability of SB202190 to block gene activation was stimulus-dependent. LPS and interferon-α (IFN-α) both up-regulated neuroleukin mRNA, but only LPS-induced neuroleukin mRNA was suppressed by SB202190. In contrast, TNF-α and LPS both induced IL-8 mRNA, and induction by either TNF-α or LPS was blocked by SB202190. These data were consistent with the ability of LPS and TNF-α, but not IFN-α, to activate p38 in monocytes. The results provide pharmacological evidence that p38 may be a key mediator of inducible gene expression in monocytes, but its role is stimulus and gene specific. J. Leukoc. Biol. 64: 409–417; 1998.
The murine neutrophil-chemoattractant chemokines LIX, KC, and MIP-2 have distinct induction kinetics, tissue distributions, and tissue-specific sensitivities to glucocorticoid regulation in endotoxemia
Authors: Rovai Leonor E , Herschman Harvey R , Smith Jeffrey B
Published: January 2018

Lipopolysaccharide-induced CXC chemokine (LIX) is a novel murine neutrophil-chemoattractant CXC chemokine cloned as a glucocorticoid-attenuated response gene. We investigated LIX message expression in an acute endotoxemia model. LIX message peaks later than KC or macrophage inflammatory protein-2 (MIP-2) and remains elevated longer in almost all tissues. Induced LIX message expression in heart is 5- to 6-fold greater than in lung and spleen, and 20-fold greater than in liver. In contrast, KC expression is equal in heart, lung, and liver, whereas MIP-2 expression is strongest in the lung. Glucocorticoid regulation of these genes also differs. Endotoxemia-induced LIX message expression in the lung is markedly enhanced in adrenalectomized mice and strongly attenuated by dexamethasone, whereas lung KC and MIP-2 expression are unaffected by glucocorticoids. It is surprising to note that endotoxemia-induced brain expression of LIX (but not KC or MIP-2) is increased by dexamethasone. These observations suggest that LIX may have biological roles distinct from KC and MIP-2. J. Leukoc. Biol. 64: 494–502; 1998.
Activation of mitogen-activated protein kinase cascades during priming of human neutrophils by TNF-α and GM-CSF
Authors: McLeish Kenneth R , Knall Cindy , Ward Richard A , Gerwins Par , Coxon Patricia Y , Klein Jon B , Johnson Gary L
Published: January 2018

The signal transduction pathways activated by tumor necrosis factor α (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF) that lead to priming of polymorphonuclear leukocytes (PMNs) are unknown. The hypotheses that these cytokines stimulate multiple mitogen-activated protein kinase (MAPK) cascades, including extracellular signal-regulated kinases (ERKs), c-Jun amino-terminal kinases (JNKs), and p38 MAPK, and that these MAPKs participate in priming of human PMNs were examined. TNF-α stimulated a dose-dependent increase in ERK and p38 MAPK activities that was maximal at 10 min. JNKs were not stimulated by TNF-α or GM-CSF. GM-CSF stimulated ERK activity comparable to that of TNF-α, but GM-CSF was a less potent stimulus of p38 MAPK activity. The tyrosine kinase inhibitor, genistein, inhibited ERK and p38 MAPK stimulation by both cytokines. The phosphatidylinositol 3-kinase inhibitor, wortmannin, attenuated stimulation of ERKs and p38 MAPK by GM-CSF, but not TNF-α. GM-CSF, but not TNF-α, stimulated wortmannin-sensitive activation of Raf-1. TNF-α and GM-CSF priming of superoxide release stimulated by N-formyl-methionyl-leucyl-phenylalanine was significantly attenuated by the MEK inhibitor, PD098059, and the p38 MAPK inhibitor, SB203580. Incubation with both MAPK inhibitors produced an additive effect. Our data suggest that TNF-α and GM-CSF activate ERKs and p38 MAPK by different signal transduction pathways. Both ERK and p38 MAPK cascades contribute to the ability of TNF-α and GM-CSF to prime the respiratory burst response in human PMNs. J. Leukoc. Biol. 64: 537–545; 1998.
High mobility group I/Y protein functions as a specific cofactor for Oct-2A: mapping of interaction domains
Authors: Abdulkadir Sarki A , Casolaro Vincenzo , Tai Albert K-F , Thanos Dimitris , Ono Santa Jeremy
Published: January 2018

The octamer motif (ATTTGCAT) present in several eukaryotic promoters and enhancers is now known to influence the transcription of several genes by interacting with members of a broad family of homeodomain proteins. The promoter of the human class II MHC gene HLA-DRA contains a conserved octamer element that can bind (among other proteins) the transcription factor Oct-2A and the high mobility group proteins (HMG) I/Y. We have previously determined that HMG I(Y) and Oct-2A cooperatively activate HLA-DRA gene expression, most likely due to the ability of HMG I(Y) to selectively recruit Oct-2A to the octamer motif. In this report, we present results of our investigations of the mechanisms of cooperative transactivation of HLA-DRA transcription by Oct-2A and HMG I(Y). We show that both the amino- and the carboxy-terminal domains of Oct-2A are required for HLA-DRA transacivation. Experiments using domain-swap chimeras of the Oct-1 and Oct-2A polypeptides indicate that cooperative activation of the DRA gene by HMG I(Y) and Oct-2A requires the carboxy-terminal domain (CTD) of Oct-2A. However, HMG I(Y) physically interacts with the conserved POU domains of both Oct-1 and Oct-2A. We therefore postulate that the nature of the CTD attached to the POU homeodomain influences the outcome of interaction with HMG I(Y). These studies support the view that HMG I(Y) is an important cofactor for HLA-DRA gene activation by Oct-2A and provide insights into its mechanism of action. J. Leukoc. Biol. 64: 681–691; 1998.
Murine leukocytes with ring-shaped nuclei include granulocytes, monocytes, and their precursors
Authors: Biermann Heike , Pietz Barbara , Dreier Rita , Schmid Kurt W , Sorg Clemens , Sunderkötter Cord
Published: January 2018

Leukocytes with ring-shaped nuclei (ring cells) are present in bone marrow (BM; ~50% of BM cells), in peripheral blood (PB), and in inflammatory infiltrates of mice, but also in humans during myeloproliferative disorders. They are usually referred to as polymorphonuclear cells (PMN), but we demonstrate that they additionally encompass different types of mononuclear (MNC)-like ring cells. PMN ring cells had constricted ring-shaped nuclei with a wide cytoplasmic center and were sorted among the GR-1high fraction. The MNC-like ring cells belonged to the GR-1low fraction. Their nuclei were not segmented and the cytoplasmic center of their nuclei was small. They were heterogeneous with one subgroup containing monocytes/macrophages according to ultrastructure, immunophenotype (BM8, F4/80, CD13, ER-HR3), activity of unspecific esterase, and phagocytosis of Leishmania major. A second subgroup contained myeloic precursor cells as they proliferated (Ki67), expressed ER-MP12, and showed on ultrastructure distribution patterns of peroxidase activity compatible with myelocytes, promyelocytes, or promonocytes. A third subgroup of cells had large, sometimes lobulated nuclei, was lineage markernegative/low (GR-1, Mac-1, B220 etc.), CD38−, but c-kit+ and sca-1+, and thus belonged to a close progeny of murine hematopoietic stem cells. In PB, ring cells encompassed mainly PMN, but also monocytes and cells with characteristics of both the granulocytic and monocytic lineage. Thus, ring cells comprise mature and precursor forms of myeloic cells. Their analysis revealed that in mice a clear distinction between the granulocytic and monocytic lineage beyond the GM-CFU stage is not always feasible. J. Leukoc. Biol. 65: 217–231; 1999.
Stimulus-specific regulation of chemokine expression involves differential activation of the redox-responsive transcription factors AP-1 and NF-κB
Authors: Roebuck Kenneth A , Carpenter Laura R , Lakshminarayanan Venkatesh , Page Scott M , Moy James N , Thomas Larry L
Published: January 2018

The promoters of the IL-8, MCP-1, and RANTES genes contain binding sites for the redox-responsive transcription factors AP-1 and NF-κB, which have been shown to be important for their expression. In this overview, we present evidence from our laboratories that the stimulus-specific regulation of these chemokines by the reactive oxidant H2O2, the proinflammatory cytokine TNF-α, and respiratory syncytial virus (RSV) is mediated in a cell type-specific manner involving different patterns of AP-1 and NF-κB binding activity. Our results demonstrate that H2O2 induction of IL-8 gene expression is linked with the selective binding of AP-1 to the IL-8 promoter, whereas TNF-α and RSV induction of IL-8 correlates with the activation of NF-κB binding. We propose that the differential activation and binding of inducible transcription factors to the promoter regions of chemokine genes provides a critical regulatory mechanism by which the CXC and CC chemokines can be selectively expressed in a cell type-specific and stimulus-specific manner. Such a regulatory mechanism of differential chemokine expression could critically influence the site- specific recruitment of distinct subsets of leukocytes to sites of inflammation and injury. J. Leukoc. Biol. 65: 291–298; 1999.
Expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in acute and chronic inflammation
Authors: Connor Elaine M , Eppihimer Michael J , Morise Zenichi , Granger D Neil , Grisham Matthew B
Published: January 2018

The objective of this study was to quantify, in vivo, constitutive and tumor necrosis factor α (TNF-α)-enhanced expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in different tissues from healthy wild-type mice (C57BL/6) as well as interleukin-10 (IL-10)-deficient mice with and without active colitis. Using the dual radiolabel monoclonal antibody technique, we found substantial constitutive expression of MAdCAM-1 in the intestine, colon, and mesenteric lymph nodes. MAdCAM-1 expression in these tissues was significantly enhanced, in a time-dependent manner, by systemic administration of TNF-α. Maximum surface expression was observed at 18 h after TNF-α administration and remained significantly elevated at 48 h post-TNF-α injection. No significant constitutive nor TNF-α-induced expression of MAdCAM-1 was detected in skeletal muscle, brain, or heart. In IL-10-deficient (IL-10 k/o) mice with no clinical or histological evidence of colitis, constitutive and TNF-α-induced expression of MAdCAM-1 in the intestine, cecum, and colon was not different from those values obtained with healthy wild-type controls. IL-10-deficient mice with active colitis exhibited a four- to fivefold greater expression of MAdCAM-1 in the cecum and colon compared with their healthy controls or to IL-10 k/o mice with no evidence of colitis. Taken together, these data demonstrate that TNF-α enhances surface expression of MAdCAM-1 in intestinal and colonic tissues to the same extent in both wild-type and IL-10 k/o mice with no colonic inflammation, whereas IL-10 k/o mice with active colitis exhibited a profound up-regulation of MAd-CAM-1 in the colon. J. Leukoc. Biol. 65: 349–355; 1999.
Inflammation of the brain in Alzheimer's disease: implications for therapy
Authors: McGeer Patrick L , McGeer Edith G
Published: January 2018

We briefly describe the similarities and differences between a systemic and a local immune reaction and review the evidence that the latter occurs in Alzheimer's disease (AD) brains. The evidence comes mainly from studies on the complement system, microglia, and cytokines, all of which are important actors in the inflammatory process. The evidence is now overwhelming that the complement proteins and many of the mediators of inflammation are produced locally by brain cells. We will mention briefly the many epidemiological studies indicating that the use of anti-inflammatory drugs reduces the incidence and slows the progress of AD. Mention will also be made of some recent work on animal models of possible relevance to AD and inflammation. J. Leukoc. Biol. 65: 409–415; 1999.
Molecular pathway involved in HIV-1-induced CNS pathology: role of viral regulatory protein, Tat
Authors: Rappaport Jay , Joseph Jeymohan , Croul Sidney , Alexander Guillermo , Valle Luis Del , Amini Shohreh , Khalili Kamel
Published: January 2018

The broad range of histological lesions associated with HIV-1 are somewhat subtle relative to the clinical manifestations that occur as a result of HIV infection. Although it is clear that HIV has a causative role in CNS disease, dementia appears to be a consequence of the infiltration of inflammatory cells and cytokine dysregulation rather than the amount of virus in CNS. The HIV transregulatory protein Tat plays an important intracellular as well as extracellular role in the dysregulation of cytokines. The cytokines and possibly chemokines that are induced by Tat modify the action of astrocytes such that the survival of neurons is compromised. Pathogenetic alteration induced by Tat involves a series of interactions between circulating monocyte/macrophages, endothelial cells, and astrocytes. Cytokine dysregulation induced by viral infection and extracellular Tat leads to alterations in expression of adhesion molecules and promotes migration of non-infected inflammatory cells into the CNS compartment. We demonstrate here that recombinant HIV-1 Tat protein introduced by stereotaxic injection into mouse brain can induce pathologically relevant alterations including macrophage invasion as well as astrocytosis. The mechanism of destruction of the CNS by Tat appears to involve autocrine and paracrine pathways that depend not only on Tat, but cytokine and chemokine signaling pathways that are altered by viral infection. In this review, we discuss various pathogenic effects of Tat in brain cells and provide experimental evidence for an increased TNF-α level in CSF in mice injected intracerebrally with Tat protein. J. Leukoc. Biol. 65: 458–465; 1999.
Vitamin E protects against polymorphonuclear leukocyte-dependent adhesion to endothelial cells
Authors: Yoshida Norimasa , Yoshikawa Toshikazu , Manabe Hiroki , Terasawa Yoshimitsu , Kondo Motoharu , Noguchi Noriko , Niki Etsuo
Published: January 2018

We evaluated the effects of α-Toc on surface expression of CD11b/CD18 on polymorphonuclear leukocytes (PMN) stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and oxidized low-density lipoprotein (oxLDL). Incubation of PMN with fMLP (1 μM) or oxLDL (100 μg/mL) increased CD11b/CD18 expression; pretreatment with α-Toc reduced in a dose-dependent manner. PMN obtained from healthy adults ingesting 600 mg α-Toc per day for 10 days were similarly incubated with fMLP or oxLDL; the surface level of CD11b/CD18 was inversely correlated with serum α-Toc concentrations. Adherence of PMN to human umbilical vein endothelial cells was increased by fMLP or oxLDL stimulation but reduced by α-Toc pretreatment or anti-CD18 monoclonal antibodies. cAMP-dependent protein kinase (PKA) and protein kinase C (PKC) activity in PMN was also assayed. A PKC inhibitor, but not a PKA inhibitor, suppressed CD11b/CD18 up-regulation, and α-Toc slightly decreased fMLP- and oxLDL-induced activation of PKC. These results suggest that α-Toc may prevent inflammation by both reducing CD11b/CD18 up-regulation and decreasing PMN-dependent adherence to EC. J. Leukoc. Biol. 65: 757–763; 1999.
Dendritic cells and MPIF-1: chemotactic activity and inhibition of endogenous chemokine production by IFN-γ and CD40 ligation
Authors: Nardelli Bernardetta , Morahan Diana K , Bong Gary W , Semenuk Mark A , Kreider Brent L , Garotta Gianni
Published: January 2018

We have examined the biological activity of the CC chemokine myeloid progenitor inhibitory factor 1 (MPIF-1) on human dendritic cells. MPIF-1 has chemotactic activity on dendritic cells derived from either peripheral blood monocytes or cord blood CD34+ progenitors. However, chemokine treatment did not induce further cell activation or maturation. In addition, MPIF-1 is constitutively released by monocyte-derived dendritic cells but not macrophages or monocytes (resting or stimulated). The proinflammatory stimuli lipopolysaccharide and tumor necrosis factor α, which induced the release of monocyte chemotactic protein-1, macrophage inflammatory protein-1α (MIP-1α), MIP-1β, and interleukin-8, did not affect MPIF-1 release. In contrast, CD40 ligation and interferon-γ treatment, while stimulating the production of the other chemokines, caused a pronounced reduction of MPIF-1 transcript and protein release. Thus, in dendritic cells the regulation of the production and release of MPIF-1 is distinct in comparison to other CC and CXC chemokines. J. Leukoc. Biol. 65: 822–828; 1999.