bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different patterns of deactivation of Chemotaxis and haptotaxis of human peripheral blood mononuclear leukocytes by soluble and surface-bound attractants
Authors: Wiedermann Christian J , Reinisch Norbert , Bellmann Romuald , Schratzberger Peter , Kowald Elisabeth , Kähler Christian M 
Published: January 2018

Abstract
Soluble mediators and inducible cell-surface and matrix-bound molecules coordinate the cascade of events giving rise to leukocyte emigration. Knowledge of the specific mechanisms underlying the attraction of cells into a local site, however, remains sketchy. In particular, it is unclear how chemoattractants cause rapidly moving immune cells to adhere to the blood vessel wall and to enter tissues. Here we show that the neuroendocrine human growth hormone, a chemoattractant for monocytes and lymphocytes in vitro, promotes haptotaxis, the migration of the cells induced by surface-bound gradients. Combination of soluble growth hormone with soluble attractants, RANTES or formyl peptide, deactivates the migratory responses, as do combinations of surface-bound growth hormone with surface-bound RANTES or formyl peptide. In contrast, exposure of mononuclear leukocytes to combinations of soluble chemotactic with surface-bound haptotactic gradients of attractants does not deactivate migration. The findings suggest that growth hormone may act as haptotactic agent, on the one hand, and that soluble attractants do not appear to affect haptotaxis when acting in concert with a surface-bound attractant, on the other. This observation may have implications for the differential regulation of leukocyte accumulation in the vessel wall at systemic and local sites.
Tumor necrosis factor triggers redistribution to a Triton X-100-insoluble, cytoskeletal fraction of β2 integrins, NADPH oxidase components, tyrosine phosphorylated proteins, and the protein tyrosine kinase p58fgr in human neutrophils adherent to fibrinogen
Authors: Yan Sen Rong , Fumagalli Laura , Dusi Stefano , Berton Giorgio 
Published: January 2018

Abstract
Tumor necrosis factor (TNF) triggers cell spreading, release of granule constituents, and production of toxic oxygen derivatives in human neutrophils adherent to fibrinogen. This response requires cytoskeleton reorganization and is dependent on expression of β2 integrins. We analyzed distribution of distinct proteins in Triton X-100–soluble and insoluble fractions in neutrophils adherent to fibrinogen. We found that stimulation of adherent neutrophils with TNF causes the redistribution to a Triton-insoluble fraction of α-actinin, β2 integrins, and the four components whose assembly constitutes an active NADPH oxidase: the gp91-phox, p22-phox, p47-phox, and p67-phox proteins. Redistribution of these different proteins to a Triton-insoluble fraction took relatively long times and was maximal after about 30 min of stimulation with TNF. Prevention of actin polymerization with cytochalasin B hampered the TNF-induced redistribution of these proteins from a Triton-soluble to an insoluble fraction. In addition, tyrosine phosphorylated proteins and the protein tyrosine kinase p58fgr were recovered in this Triton-insoluble fraction. These findings show that stimulated, β2 integrin–dependent adhesion of neutrophils to fibrinogen is accompanied by redistribution to cytoskeletal structures of (1) β2 integrins, that is, neutrophil receptors for fibrinogen; (2) proteins involved in neutrophil effector functions, that is, components of NADPH oxidase; and (3) tyrosine phosphorylated proteins and the protein tyrosine kinase p58fgr, molecules that are potentially involved in the formation of a submembranous signaling complex.
Taurine chloramine, a product of activated neutrophils, inhibits in vitro the generation of nitric oxide and other macrophage inflammatory mediators
Authors: Marcinkiewicz Janusz , Grabowska Agnieszka , Bereta Joanna , Stelmaszynska Teresa 
Published: January 2018

Abstract
Taurine (Tau) is an exceptionally abundant free amino acid in the cytosol of inflammatory cells and especially in neutrophils. Taurine protects cells from self-destruction during processes that generate oxidants. The major function of Tau in leukocytes is to trap chlorinated oxidants (HOCl). Taurine reacts with HOCl to produce the long-lived compound taurine chloramine (TauCl). Previously, we have shown that other products of the neutrophil chlorinating system are able to modify functions of macrophages. In this study, we investigated in vitro the influence of TauCl on the generation of inflammatory mediators by activated macrophages. We have found that TauCl inhibited the generation of nitric oxide, prostaglandin E2, tumor necrosis factor α, and interleukin-6, but TauCl slightly enhanced the release of IL-1α. The formation of nitrites by interferon-γ-activated macrophages was inhibited by TauCl in a dose-dependent manner. Taurine chloramine also reduced the level of inducible nitric oxide synthase (iNOS) mRNA in macrophages, in a similar concentration-dependent manner. Although our experiments do not exclude a direct effect of TauCl on enzymatic activity of iNOS, the inhibition of iNOS expression seems to be the major mechanism responsible for suppression of NO formation. Finally, we discuss the biological role of TauCl in vivo. We suggest that at the site of inflammation TauCl works as a specific signaling molecule of activated neutrophils that coordinates the generation of inflammatory mediators in macrophages.
The Duffy antigen receptor for chemokines: structural analysis and expression in the brain
Authors: Horuk R , Martin, A , Hesselgesser J , Hadley T , Lu Zhao-hai , Wang Zi-xuan , Peiper S C 
Published: January 2018

Abstract
The Duffy antigen receptor for chemokines (DARC) is expressed in human erythrocytes and on endothelial cells lining postcapillary venules in kidney and spleen. DARC is a promiscuous chemokine receptor and a binding protein for the malarial parasite Plasmodium vivax. The expression of DARC by subsets of endothelial cells and neurons in discrete anatomic sites in the brain suggests that this enigmatic receptor may have multiple roles in normal and pathological physiology. Conservation of this promiscuous chemokine binding function is evident from the similarity in nucleotide sequence of DARC homologues from multiple species, as well as the high-affinity binding of human chemokines to murine and avian erythrocytes. Analysis of the functional domains of DARC using chimeric receptors and monoclonal antibodies to multiple extracellular domains localized chemokine binding to structures in the amino terminal extracellular domain (E1). Scatchard analysis demonstrated that a chimeric DARC receptor, composed of the E1 domain of DARC and the predicted hydrophobic helices and loops of interleukin-8RB (IL-8RB), bound IL-8, and MGSA with K D values almost identical to the wild type receptors and bound a repertoire of C-X-C and C-C chemokines characteristic of DARC. Although numerous reports have demonstrated that chemokines such as IL-8 are expressed in the brain, presumably by glial cells, little insight into the nature of their role in normal or pathological physiology in the nervous system has developed because the target cells that express the corresponding receptors have not yet been identified. Northern blotting experiments suggest that mRNA encoding DARC are expressed in the central nervous system, however, interpretation of this is unclear because of the ubiquitous expression of DARC lining postcapillary venules. This study provides direct evidence to localize expression of DARC in the cental nervous system. Immunohistochemical examination of human archival sections of the brain with monoclonal antibodies specific for DARC localize expression of DARC to cell bodies and processes of Purkinjie cells in the cerebellum. The immunohistochemical findings were supported by analysis of chemokine binding and radioligand crosslinking with membranes made from various brain fractions. The hierarchical expression of DARC in neurons in the cerebellum suggests that chemokines may play an important role in the modulation of neuronal activity by glial cells.
Effects of interleukin-13 on human neutrophil functions
Authors: Girard Denis , Faquin Robert , Naccache Paul H , Beaulieu André D 
Published: January 2018

Abstract
It was recently shown that interleukin-13 (IL-13) induces the expression and release of the IL-1 decoy receptor (type II) in human neutrophils along with the production of the IL-1 receptor antagonist. In the present study we focused on further studying the modulatory effects of IL-13 on these cells. We found that recombinant human IL-13 (rhIL-13) induces cellular morphological changes in neutrophils that are typical of activated cells. Furthermore, rhIL-13 was shown to increase tyrosine phosphorylation of several neutrophil proteins. We also demonstrate that this cytokine stimulates de novo RNA synthesis in a concentration-dependent fashion as measured by [5-3H]uridine incorporation and that rhIL-13 induces the synthesis of several neutrophil proteins according to high-resolution two-dimensional gel electrophoresis of metabolically [35S]-labeled cells. We observed that the IL-8 levels in the external milieu of IL-13-stimulated cells was almost fivefold increased when compared with control cells. Finally, we observed that rhIL-13 has no significant effect on phagocytosis and apoptosis. Taken together, our results demonstrate that IL-13 is a modulator of several human neutrophil functions. This leads us to conclude that the modulatory role of IL-13 on human neutrophils, a potentially important anti-inflammatory cytokine, is more complex than previously believed. Furthermore, because we show that the synthesis of several as yet unidentified proteins was up-regulated by IL-13, our findings open new avenues of research on the effects of this cytokine on human neutrophils.
Immunoregulation by interleukin-12
Authors: Trinchieri Giorgio , Gerosa Franca 
Published: January 2018

Abstract
Interleukin-12 (IL-12) is a heterodimeric cytokine produced primarily by antigen-presenting cells (monocytes, macrophages, dendritic cells, and B cells). Its production is stimulated by bacteria, bacterial products, and intracellular parasites and enhanced by priming with granulocyte-macrophage colony-stimulating factor (CM-CSF) and interferon-γ (IFN-γ) or inhibited by IL-10. The major biological activity of IL-12 is on T and natural killer (NK) cells in which it increases cytokine production, proliferation, and cytotoxicity. Its production occurs several hours after exposure to infectious agents, which induces a rapid production of IFN-γ by NK and later by T cells. This IFN-γ potentiates antigen-presenting cell functions important in clearing infectious agents (phagocytosis, oxidative burst, and production of nitrous oxide) and also increases further production of IL-12. IL-12 has been clearly demonstrated to be important in the generation of CD4 and CD8 type 1 T cells both in vivo and in vitro. Our data reveals that IL-12 primes naive T cells for high IFN-γ and IL-10 production, whereas IL-4 is required for IL-4 priming, thus suggesting that these genes and possibly others are independently regulated. IL-12 is therefore involved in the skewing of cytokine production toward a type 1 and has been implicated in being involved in selective mechanisms of established T cells. It is now becoming clear that the IL-12 acts as both a proinflammatory cytokine and an immunomodulator and therefore bridges the innate and adaptive immune responses.
IL-4-dependent proliferation of BA/F3 cells expressing a growth-negative mutant of the human IL-4 receptor is restored by enforced expression of Bcl-2
Authors: Chung Johanna , Deutsch Harald H J , Kalthoff Frank S 
Published: January 2018

Abstract
We have studied the regulation of growth and apoptosis in murine BA/F3 cells stably expressing cytoplasmic deletion mutants of the human interleukin-4 receptor (hIL-4R). Previously, we showed that BA/F3 cell transfectants expressing a cytoplasmic deletion mutant of the hIL-4R that lacks the region between Thr(462) and Ala(580), referred to as δR3, fails to proliferate in the presence of hIL-4. Here we report that supertransfection of δR3-expressing cells with a constitutively active murine bcl-2 gene results in prolonged survival of the δR3/bcl-2 double transfectants in the absence of cytokines. More importantly, however, the constitutive expression of Bcl-2 restored their capacity to grow permanently with hIL-4. This may provide an explanation for the discrepancy with previous reports showing growth mediation by hIL-4R truncated at position 367.
Binding affinities of the SH2 domains of ZAP-70, p56/ck and Shc to the chain ITAMs of the T-cell receptor determined by surface plasmon resonance
Authors: Labadia M E , Ingraham R H , Schembri-King J , Morelock M M , Jakes S 
Published: January 2018

Abstract
The chains of the T cell receptor complex play a critical role in the initiation of proximal signaling events upon T cell activation. Three pairs of potential tyrosine phosphorylation sites are located within the cytoplasmic domains of the chains. Subsequent to engagement of the T cell receptor, one or more of these tyrosine residues is phosphorylated. The phosphotyrosine residues, along with flanking amino acids, form an activation motif (and are shared by signaling subunits in the TCR, B cell receptor, and FcγRI) termed tyrosine-based activation motifs (ITAMs). ITAMs serve as binding sites for SH2 domain-containing proteins. Recent evidence suggests that the chains provide docking space for several key signal transduction molecules such as ZAP-70, p56 lck, and Shc. To determine if ZAP-70, p56 lck, and Shc bind to particular chain ITAM sequences, quantitative free-solution measurements of binding affinities (Kd) were obtained by use of surface plasmon resonance technology. The results indicate that binding affinities of distinct SH2 domains to individual and paired phosphorylation sites greatly differ, and may dictate the sequence of signal transduction events.
Heat shock protein-peptide complexes for use in vaccines
Authors: Heike Michael , Noll Bernhard , zum Büschenfelde Karl-Hermann Meyer 
Published: January 2018

Abstract
The heat shock proteins gp96, HSP70, and HSP90 are complexed to a diverse array of cellular proteins and peptides as a consequence of their chaperone functions. There is good experimental evidence that vaccination with these heat shock protein-peptide complexes elicit immune responses against chaperoned peptide antigens. As shown with gp96, this requires internalization of the heat shock protein-peptide complexes by macrophages and processing of the chaperoned peptides for class I restricted presentation. Via this process, primarily CD8+ antigen-specific T cells are primed by gp96 vaccination. This might represent a general mechanism for priming of MHC-class I restricted T cells by professional antigen-presenting cells. At least gp96 has been shown to be associated with peptides that are not selected by the MHC haplotype of the harboring cell. This allows for immunization with gp96-peptide complexes across MHC barriers, for example against shared tumor antigens or viral antigens.
NO is not sufficient to explain maximal cytotoxicity of tumoricidal macrophages against an NO-sensitive cell line
Authors: Mateo Romeo B , Reichner Jonathan S , Albina Jorge E 
Published: January 2018

Abstract
Nitric oxide (NO) is a macrophage cytotoxic effector. Results presented here, however, demonstrate that NO does not fully explain macrophage cytotoxicity against NO-sensitive cells because (1) inhibition of NO production by activated macrophages reduces, not eliminates, cytotoxicity; (2) NO produced chemically in amounts equimolar to those released from macrophages fails to lyse P815 cells; and (3) macrophages isolated from wounds 10 days after injury generate NO just as tumoricidal activated macrophages but are not tumor cytotoxic. The noncytotoxic nature of these wound-derived macrophages is not explained by the release of inactive forms of NO, because they suppress lymphocyte proliferation in an NO-dependent manner, nor by the production of cytoprotective molecules, because their addition to activated macrophage–tumor cell cocultures does not quench cytotoxicity. Interestingly, cytotoxicity can be aroused in day 10 wound-derived macrophages by culture with lipopolysaccharide, and macrophages harvested earlier in the development of the wound are cytotoxic. By generating NO but not killing an NO-sensitive cell, day 10 wound-derived macrophages demonstrate that NO production is not sufficient to account for the killing of an NO-sensitive tumor by macrophages.
Role of interferon-γ in immunity to herpes simplex virus
Authors: Yu Zhiya , Manickan Elanchezhiyan , Rouse Barry T 
Published: January 2018

Abstract
Removal of herpes simplex virus (HSV)-infected cells from peripheral sites such as the skin is mainly an activity of T cells, particularly the CD4+ T subset. Such cells orchestrate an inflammatory response with interferon-γ (IFN-γ) appearing to play the essential role in viral clearance. In accordance with this hypothesis, we show that infection of BALB/c background mice expressing the knockout phenotype for IFN-γ (GKO mice) are significantly more susceptible to the development of cutaneous zosteriform lesions than are wild-type. However, following HSV immunization, GKO mice become solidly immune to the development of zosteriform lesions. In addition, the transfer of T cells from immune GKO mice to nude mice recipients renders them resistant to zosteriform lesions. Our results are discussed in terms of the major and compensatory mechanisms available to the body to effect immunity to viral infections.
C-C chemokine-induced eosinophil chemotaxis during allergic airway inflammation
Authors: Lukacs Nicholas W , Standiford Theodore J , Chensue Stephen W , Kunkel Robin G , Stricter Robert M , Kunkel Steven L 
Published: January 2018

Abstract
The production of eosinophil-specific chemotactic factors during allergic airway responses may be a pivotal event resulting in eosinophil accumulation, activation, and airway damage. Recent studies have identified specific chemokines that may play crucial roles in recruitment of eosinophils to the site of allergic reactions. In this study we have utilized an established model of schistosome egg antigen (SEA)-mediated allergic responses to examine the role of specific C-C chemokines [macrophage inflammatory protein-1α (MIP-1α), RANTES, and monocyte chemoattractant protein-1 (MCP-1)] in eosinophil recruitment. We have previously identified a role for MIP-1α in eosinophil accumulation in the lung and airway during allergic airway inflammation. We extend those studies using in vitro eosinophil chemotaxis to establish that both MIP-1α and RANTES are potent eosinophil chemotactic factors in lungs during allergic airway responses. Morphometric analysis demonstrated a peribronchial accumulation of eosinophils within the lungs beginning at 8 h, peaking at 24 h, and plateauing at 48–96 h after allergen (SEA) challenge. Utilizing whole-lung homogenates from allergen-challenged mice, in vitro eosinophil chemotactic assays demonstrated significant increases in eosinophil chemotactic activity with 8-h lung homogenates and peak activity with samples from 24-h lung homogenates. These data correlated with the morphometric analysis of peribronchial eosinophil accumulation in situ. When lung homogenates from allergen-challenged mice were preincubated in vitro with antibodies specific for MIP-1α, RANTES, or MCP-1, a significant reduction in eosinophil chemotaxis was observed with only MIP-1α and RANTES neutralization. Altogether, these studies indicate that RANTES and MIP-1α are major eosinophil chemotactic factors produced during allergic airway responses.
Surface thiols of human lymphocytes and their changes after in vitro and in vivo activation
Authors: Lawrence David A , Song Renjie , Webert Peter 
Published: January 2018

Abstract
Cellular thiols have long been known to play a role in cell activation and proliferation; however, the differential expression of surface thiols on the lymphoid subsets had not been described. Neither was it known whether alteration of surface thiols occurs after exposure to mitogens or infectious agents. Herein, an impermeant thiol-specific fluorescent probe was employed for flow cytometric analysis of surface thiols. Quantification of surface thiols on resting lymphocytes revealed that some subsets expressed different concentrations of surface thiols (CD19+ &gt; CD8+ &gt; CD4+). Furthermore, surface thiols increased on all subsets by 8 h after mitogenic activation. This increase was blocked by cycloheximide or monensin but not by actinomycin D or inhibition of glutathione synthesis by buthionine sulfoximine. In addition, bacitracin, an inhibitor of protein disulfide isomerase, inhibited the increase in surface thiols and DNA synthesis. Lymphocytes from HIV-infected individuals displayed increased surface thiols on CD19+ and CD4+ cells but not CD8+ cells. Although cellular thiols in general have been believed to play a role in protection against oxidants, signaling associated with cell growth, and apoptosis, there is now evidence that changes in exofacial thiols appear to be involved in some of these critical cell reactivities. Thus, quantitative and possibly qualitative differences in surface thiols correlate with membrane differences between lymphoid subsets and with their differential sensitivities to oxidative stress, which suggests that the mechanisms by which surface thiols are maintained and modified after activation are important cellular functions that need to be further evaluated.
Microbial killing by human neutrophil cytokineplasts: similar suppressive effects of reversible and irreversible inhibitors of nitric oxide synthase
Authors: Malawista Stephen E , Montgomery Ruth R , van Blaricom Gretchen 
Published: January 2018

Abstract
Employing anucleate, granule-poor, motile fragments from human blood neutrophils (cytokineplasts; CKP), we previously provided evidence for a new staphylococcal killing pathway for human neutrophils involving reactive nitrogen intermediates: the NO synthase inhibitor Nω-monomethyl-L-argmine (NMMA), an analogue of L-arginine (L-Arg), substantially decreased the killing capacity of CKP for Staphylococcus aureus (Staph), an effect reversible by excess L-Arg but not D-Arg. We have extended these findings to two irreversible NO synthase inhibitors: the first, N-iminoethyl-L-ornithme (L-N10), is an L-Arg analogue; the other, diphenyleneiodonium (DPI), is not. After 60 min of incubation with bacteria, despite having taken up somewhat fewer staphylococci than did controls, cytoplasts treated with NO synthase inhibitors had many more live, CKP-associated bacteria: for NMMA, 6.9 times more (40.0% of the inoculum vs. 5.8%; n = 8, P = 0.003); for L-N10, 3.6 times more (25.5 vs. 7%; n = 4, P = 0.004); for DPI, 5.8 times more (37.4 vs. 6.4%; n = 7, P = 0.002). Results were similar after only 20 min of incubation. In two experiments in which the Gram-negative bacterium, Serratia marcescens, was employed instead of Staph, the results were again similar. In contrast, killing of either bacterium by intact neutrophils (PMN) was not inhibited by NMMA, by L-N10, or by DPI, a failure most likely attributable to their granule content. The irreversible inhibitors of NO synthase will be especially useful in analyzing particular effects on CKP employed in multicellular systems.