bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of tyrosine phosphorylation in inhibition of fMLP-induced PLD activation by N-acetyl-L-cysteine in differentiated HL60 cells
Authors: Nakamura Mitsuhiro , Nakashima Shigeru , Katagiri Yoshihiro , Nozawa Yoshinori
Published: January 2018

N-acetyl-L-cysteine (NAC), which is known as a multipotential agent; an antioxidant, a thiol reagent, or a tyrosine kinase inhibitor, inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced phospholipase D (PLD) activation in HL60 cells in a concentration-dependent manner (IC50 = 2 mM). Its inhibitory mechanism was examined in this study to gain insight into the regulation of PLD activity. NAC had no direct effect on membrane PLD activity in an in vitro assay system. fMLP-induced formation of inositol phosphates via phospholipase C (PLC) was not affected by the drug, suggesting that the receptor-G protein coupling was not inhibited. H2O2, which is known to induce PLD activation in several types of cells, failed to activate PLD in HL60 cells. Pretreatment of 3-amino-1,2,4-triazole (ATZ), a catalase inhibitor, did not enhance fMLP-induced PLD activation. NAC inhibited fMLP-induced tyrosine phosphorylation of several protein bands (42, 44, 64, and 138 kDa) in a concentration-dependent manner. The temporal and concentration-dependent inhibitory profiles for tyrosine phosphorylation of 64- and 138-kDa proteins were well correlated with PLD activation. However, thiol reagents, 1 mM 2,3-dimercapto-1-propanol (2,3-DMP), 1 mM dithiothreitol (DTT), and 2 mM cysteine also did not suppress protein tyrosine phosphorylation or PBut formation by fMLP. Wortmannin, a selective phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, inhibited these two tyrosine phosphorylation bands. These results suggest that NAC inhibits fMLP-induced PLD activation through blockage of protein tyrosine phosphorylation, which is located at the downstream of PI-3 kinase.
Soluble receptors in human disease
Authors: Heaney Mark L , Golde David W
Published: January 2018

Soluble cytokine receptors naturally arise from genes encoding membrane-bound receptors or are direct derivatives of the receptors themselves. There is mounting evidence that soluble receptors play important roles in human disease states. In many cases, soluble receptors appear to play an integral part in the dynamic interaction between ligands and their membrane-bound receptors in maintaining and restoring health after a pathological insult but, in some instances, dysregulated expression of soluble receptors can contribute to disease pathology. Nonetheless, an appreciation of the biological actions of soluble receptors, particularly as cytokine inhibitors, has led to their therapeutic use in human diseases. Although early clinical trials of soluble receptors have had unexpected toxicities, their application in medicine continues to advance and it is likely that soluble receptors will join hormones, cytokines, and growth factors as established biological therapies. J. Leukoc. Biol. 64: 135–146; 1998.
Interactive role of nitric oxide and superoxide anion in neutrophil-mediated endothelial cell injury
Authors: Kausalya Santhanam , Nath Jayasree
Published: January 2018

This study addresses the interactive role of nitric oxide (NO) and reactive oxygen intermediates (ROI) by direct quantitation of NO and superoxide (O2–) in human neutrophil (PMN)-endothelial cell (EC) coculture during PMN-mediated EC injury. The results directly demonstrate an inverse correlation between NO and ROI levels in PMN-EC coculture, which significantly alters the PMN-EC adhesion and PMN-mediated EC killing. N-formyl-methionyl-leucyl-phenylalanine (fMLF)-stimulated PMN adhesion to cytokine-treated EC was decreased (>25%) in the presence of S-nitroso-N-penicillamine, a NO donor. NO also inhibited EC killing by stimulated PMN, suggesting its cytoprotective role. In addition, a significant decrease in NO levels was observed in the PMN-EC coculture compared with the EC cultured alone (422.45 ± 35.76 vs. 800.79 ±41.69 pmol). The reduced NO levels were restored by the addition of superoxide dismutase, a scavenger of O2–, suggesting that PMN-derived O2– is involved in the neutralization of NO in the coculture. The results indicate an inverse correlation between NO and O2– in PMN-EC interactions and suggest the need for a critical balance between these two radicals in the regulation of PMN-mediated tissue injury. J. Leukoc. Biol. 64: 185–191; 1998.
IL-4 and CD40 ligation affect differently the differentiation, maturation, and function of human CD34+ cell-derived CD1a+CD14− and CD1a−CD14+ dendritic cell precursors in vitro
Authors: Canque Bruno , Camus Sandrine , Yagello Micael , Gluckman Jean Claude
Published: January 2018

We examined the effect of interleukin (IL)-4 or CD40 ligation on the differentiation and maturation of CD1a+CD14– and CD1a–CD14+ dendritic cell (DC) precursors. Cord blood CD34+ cells were cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor α (TNF-α), to which stem cell factor and Flt-3 ligand were added for 5 days. Phenotypic analysis of DC precursors on culture day 7 showed that CD1a+CD14– cells expressed higher CD11c and CD80 levels and lower CD116/GM-CSFR and CCR-5 levels than their CD1a–CD14+ counterparts. Culturing CD1a+CD14– precursors with GM-CSF and TNF-α resulted in DC with heterogeneous CD1a, HLA;SMDR (DR), CD11b, and CD83 expression, 10% of which acquired CD14. IL-4 and CD40 ligation affected their differentiation in contrasting ways: IL-4 induced CD1ahiCD14– DRloCD11b+CD83–S100+ DC with reduced MLR-stimulating capacity, whereas CD40 ligation led to CD1alo/-CD14–CD40–DRhiCD11b–CD83+S100+/– DC with stronger MLR-stimulating capacity. Also, both IL-4 and CD40 ligation promoted RelB expression and nuclear translocation. When CD1a–CD14+ precursors were maintained in only the presence of GM-CSF and TNF-α, this led to mixed populations of adherent macrophages and nonadherent CD1a–CD14+ monocytes, and of CD1a+CD14– and CD1a+CD14+ DC, which were DRloCD11b+-CD83–S100–. IL-4 or CD40 ligation prevented their differentiation into macrophages and resulted in DC with phenotypes close to those issued from CD1a+CD14– precursors, with only a minority staying CD14+ but most being S100–; their MLR-stimulating capacity also increased but remained lower than that of DC differentiated from CD1a+CD14– precursors. Thus, IL-4 or CD40 ligation induced CD1a+CD14– and CD1a–CD14+ DC precursors to differentiate into phenotypically close but functionally different DC populations, suggesting that DC function is primarily determined by their origin. The heterogeneity of DC should then be related to different developmental pathways and to different stages of maturation/activation. J. Leukoc. Biol. 64: 235–244; 1998.
Combinatorial requirements for adhesion molecules in mediating neutrophil emigration during bacterial peritonitis in mice
Authors: Mizgerd Joseph P , Quinlan William M , LeBlanc Brian W , Kutkoski Gregory J , Bullard Daniel C , Beaudet Arthur L , Doerschuk Claire M
Published: January 2018

To investigate the requirements for adhesion molecules in neutrophil emigration during peritonitis, mice received intraperitoneal injections of Streptococcus pneumoniae while the functions of multiple adhesion molecules were blocked. Emigration after 4 h was compromised by antibodies against ICAM-1 or genetic deficiency of ICAM-1. Anti-CD11a/CD18 antibodies decreased emigration in ICAM-1 mutant mice, suggesting that ICAM-1 independent emigration requires CD11/CD18 complexes. In contrast, mice mutant in ICAM-1 plus E-selectin showed no defect in emigration, suggesting that E-selectin commits neutrophils to an ICAM-1-dependent pathway during streptococcal peritonitis. However, in mutant mice lacking the three endothelial adhesion molecules E-selectin, P-selectin, and ICAM-1, emigration after 4 h was significantly compromised. Thus, P-selectin is essential to ICAM-1-and E-selectin-independent acute peritoneal inflammation. After 24 h of peritonitis, there were no differences between WT and E-selectin/P-selectin/ICAM-1 mutant mice, demonstrating that these endothelial adhesion molecules are not essential to neutrophil emigration during later stages of peritonitis. J. Leukoc. Biol. 64: 291–297; 1998.
A 70-kDa amino-terminal fibronectin fragment supports gelatin binding to macrophages and decreases gelatinase activity
Authors: Penc Stanley F , Blumenstock Frank A , Kaplan John E
Published: January 2018

We previously reported that a macrophage response that increased binding to 125I-radiolabeled soluble denatured collagen (gelatin) was induced by preincubation of macrophage with a 70-kDa amino-terminal fibronectin fragment and soluble nonlabeled gelatin [S. F. Penc, F. A. Blumenstock, J. E. Kaplan (1995) J. Leukoc. Biol. 58, 501–509]. We now report that neither protein synthesis nor recycling of receptors between the cell surface and interior were required for this response. However, removal of cell surface components with trypsin demonstrated that induced gelatin binding required native cell surface constituents. It was found that in the presence of the 70-kDa fibronectin fragment and gelatin, matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9) activity in the cell layers was significantly decreased or undetectable, respectively. Similar levels of increased gelatin binding could be reproduced after inhibition of matrix-degrading metalloprotease activity with 1′10-phenanthroline. These results demonstrate that a macrophage specific response that decreased gelatinase activity and increased gelatin binding was initiated by interaction with a 70-kDa fibronectin fragment and gelatin. J. Leukoc. Biol. 64: 351–357; 1998.
IL-4 and a glucocorticoid up-regulate CXCR4 expression on human CD4+ T lymphocytes and enhance HIV-1 replication
Authors: Wang Jianbin , Harada Akihisa , Matsushita Shuzo , Matsumi Shintaro , Zhang Yi , Shioda Tatsuo , Nagai Yoshiyuki , Matsushima Kouji
Published: January 2018

CXCR4 is a key co-receptor required for the infection of T-tropic HIV-1 strain of CD4+ T lymphocytes. The regulation of this chemokine receptor was therefore studied. Th2 polarized cells expressed more CXCR4 than Th1 cells. Among a panel of cytokines and stimulants, a Th2 type cytokine interleukin-4 (IL-4) selectively up-regulated the mRNA level as well as surface protein expression of CXCR4 within 16 h. In addition, CXCR4 was also up-regulated by a glucocorticoid, dexamethasone. These treated cells became more responsive in transendothelial migration assays to the specific CXCR4 ligand, SDF-1α. Furthermore, up-regulation of CXCR4 was also associated with the enhancement of HIV replication in human CD4+ T lymphocytes. This study indicates the enhanced T-tropic HIV-1 infection to CD4+ T lymphocytes through up-regulation of CXCR4 by several immunomodulating agents, IL-4, and a glucocorticoid. These findings may explain the shift to T-tropic HIV-1 dominance during AIDS progression when Th2 comes to predominate. J. Leukoc. Biol. 64: 642–649; 1998.
Platelet-activating factor induces a concentration-dependent spectrum of functional responses in bovine neutrophils
Authors: Swain Steve D , Bunger Peggy L , Sipes Karen M , Nelson Laura K , Jutila Kathryn L , Boylan Shane M , Quinn Mark T
Published: January 2018

We characterized the dose response of bovine neutrophils to platelet-activating factor (PAF) with respect to the following functions: calcium flux and membrane potential changes, actin polymerization, degranulation, and the production and/or priming of the oxidative burst. PAF at very low concentrations (10 and 10 M) caused changes in intracellular calcium and membrane potential in bovine neutrophils, whereas moderate PAF concentrations (≥10–7 M) resulted in increased actin polymerization. Degranulation responses to PAF were more complex: low concentrations (10–9 M) caused secretory granule degranulation, moderate doses (≥ 10–7 M) caused specific granule degranulation, whereas azurophil degranulation only occurred at high (10–5 M) PAF concentrations. Treatment of bovine neutrophils with PAF at concentrations ≥10–7 M also caused up-regulation of the adhesion molecules Mac-1 and L-selectin. PAF stimulation resulted in a very weak [compared to phorbol myristate acetate (PMA)] oxidative burst in bovine neutrophils, and only at high (10–6 M) concentrations. Unlike human neutrophils, bovine neutrophils were poorly primed by PAF treatment. Only high concentrations of PAF (10–5 M) caused an increased rate of PMA-stimulated superoxide production, although lower doses of PAF did reduce the lag time preceding the PMA-induced oxidative burst. The overall pattern that can be inferred is that lower concentrations of PAF promote neutrophil sensitivity and interaction by selective degranulation, up-regulation of adhesion molecules, and increased actin polymerization. In contrast, higher PAF concentrations can promote, albeit weakly, more direct bactericidal responses, such as the release of reactive oxygen species and granule enzymes. The ability of PAF to modulate a graded response in bovine neutrophils would allow the cell to respond proportionally to the severity of a stimulus. J. Leukoc. Biol. 64: 817–827; 1998.
Anti-human RP105 sera induces lymphocyte proliferation
Authors: Roshak Amy K , Anderson Karen M , Holmes Stephen D , Jonak Zdenka , Bolognese Brian , Terrett Jonathan , Marshall Lisa A
Published: January 2018

Cellular environment dictates whether antigen binding to the B lymphocyte receptor together with co-stimulatory molecules will result in proliferation, anergy, or apoptosis. Murine RP105 is a member of the leucine-rich repeat family of proteins, which is specifically expressed on mature B cells. Monoclonal antibodies to the murine RP105 induce proliferation and protect B cells from apoptosis, suggesting an important regulatory role in murine B lymphocyte function. We identified a human RP105 homolog and mapped the gene to chromosome 5q 12.3-13.1. Tissue distribution analysis shows that the transcript is found predominately in lymphoid tissues including spleen, tonsils, appendix, and peripheral blood leukocytes. Polymerase chain reaction analysis of isolated primary human cell populations confirms that mRNA exists in spleen B lymphocytes and monocytes but not T lymphocytes. Western blot analysis demonstrates specific expression of human RP105 in human B lymphocytes. Murine anti-human RP105 sera was generated using DNA immunization. The antisera contained antibodies that recognized and bound to human B lymphocytes from both spleen and peripheral blood as assessed by flow cytometry. Assessment of biological function showed that human peripheral blood leukocytes incubated with anti-RP105 sera were induced to proliferate as measured by tritiated thymidine incorporation. Moreover, anti-CD40 and interleukin-4-treated cells but not those exposed to anti-RP105 sera produced soluble CD23, suggesting distinct functional roles. This is the first demonstration of both the existence of RP105 protein on human B lymphocytes and its role in the regulation of B lymphocyte activation. J. Leukoc. Biol. 65: 43–49; 1999.
Regulation of IL-8RA (CXCR1) expression in polymorphonuclear leukocytes by hypoxia/reoxygenation
Authors: Grutkoski P S , Graeber C T , D'Amico R , Keeping H , Simms H H
Published: January 2018

Interleukin-8 (IL-8) is an important mediator of neutrophil (PMN) function and the type A IL-8 receptor (IL-8RA) mediates these pro-inflammatory signals. Hypoxia or hypoxia/reoxygenation (H/R) affects the production of IL-8, but no data is available regarding its effect on IL-8RA expression. The purpose of this study was to determine the effects of hypoxia and/or H/R on the expression of IL-8RA in PMN. We demonstrated that IL-8RA mRNA levels were similar under normoxic and hypoxic conditions but H/R resulted in a significant reduction in mRNA expression between 30 and 60 min. IL-8RA protein also decreased with reoxygenation of whole blood, which was altered by the addition of specific antioxidants. Therefore, H/R appears to attenuate the effect of IL-8 by down-regulating IL-8RA in PMN. These data show that changes in oxygen tension within the wound site not only affect the expression of inflammatory cytokines, but also control their actions by regulating their receptors. J. Leukoc. Biol. 65: 171–178; 1999.
Leukocyte subsets and neutrophil function after short-term spaceflight
Authors: Stowe Raymond P , Sams Clarence F , Mehta Satish K , Kaur Indreshpal , Jones Michael L , Feeback Daniel L , Pierson Duane L
Published: January 2018

Changes in leukocyte subpopulations and function after spaceflight have been observed but the mechanisms underlying these changes are not well defined. This study investigated the effects of short-term spaceflight (8–15 days) on circulating leukocyte subsets, stress hormones, immunoglobulin levels, and neutrophil function. At landing, a 1.5-fold increase in neutrophils was observed compared with preflight values; lymphocytes were slightly decreased, whereas the results were variable for monocytes. No significant changes were observed in plasma levels of immunoglobulins, cortisol, or adrenocorticotropic hormone. In contrast, urinary epinephrine, norepinephrine, and cortisol were significantly elevated at landing. Band neutrophils were observed in 9 of 16 astronauts. Neutrophil chemotactic assays showed a 10-fold decrease in the optimal dose response after landing. Neutrophil adhesion to endothelial cells was increased both before and after spaceflight. At landing, the expression of MAC-1 was significantly decreased while L-selectin was significantly increased. These functional alterations may be of clinical significance on long-duration space missions. J. Leukoc. Biol. 65: 179–186; 1999.
Functional deficiencies of peritoneal cells from gene-targeted mice lacking G-CSF or GM-CSF
Authors: Zhan Yifan , Basu Sunanda , Lieschke Graham J , Grail Dianne , Dunn Ashley R , Cheers Christina
Published: January 2018

Gene-targeted mice lacking the hemopoietic growth factors, granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage (GM)-CSF, show increased susceptibility to infection with the facultative intracellular bacterium, Listeria monocytogenes. The resident peritoneal cell populations from G-CSF-/- and GM–CSF-/- mice showed reduced production of the bactericidal molecule nitric oxide. Macrophage-mediated tumoricidal activity and phagocytosis of Listeria were reduced in G-CSF-/-, but not in GM-CSF-/-, mice. In G-CSF-/- mice, there was an unexpected expansion (from 18% in WT to 38%) of a population of cells with morphology intermediate between typical macrophages and typical lymphocytes. These cells had some of the features of poorly differentiated macrophages, being adherent to plastic but poorly phagocytic, nonspecific esterase positive but myeloperoxidase negative. They were largely negative for the macrophage marker F4/80 and for Thy1, B220, and Gr1. Their disproportionate presence, and the corresponding deficiency in typical macrophages, possibly accounts for some of the functional deficiencies observed in G-CSF-/- mice. J. Leukoc. Biol. 65: 256–264; 1999.
Transfection of human macrophages by lipoplexes via the combined use of transferrin and pH-sensitive peptides
Authors: Simões Sergio , Slepushkin Vladimir , Pretzer Elizabeth , Dazin Paul , Gaspar Rogério , de Lima Maria C Pedroso , Düzgüneş Nejat
Published: January 2018

The crucial function of macrophages in a variety of biological processes and pathologies render these cells important targets for gene therapeutic interventions. Commonly used synthetic gene delivery vectors have not been successful in transfecting these non-dividing cells. A combination strategy involving cationic liposomes to condense and carry DNA, transferrin to facilitate cellular uptake, and the pH-sensitive peptide GALA to promote endosome destabilization, resulted in significant expression of a luciferase gene. Transfection of macrophages was dependent on the degree of differentiation of the cells. The quaternary complexes of cationic liposomes, DNA, transferrin, and GALA exhibited a net negative charge, which may obviate a limitation of cationic synthetic vectors in vivo. The lack of cytotoxicity and the expected lack of immunogenicity of these complexes may render them useful for gene delivery to macrophages in vivo. J. Leukoc. Biol. 65: 270–279; 1999.
Induction of NOS in rat blood PMN in vivo and in vitro: modulation by tyrosine kinase and involvement in bactericidal activity
Authors: Fierro Iolanda M , Nascimento-DaSilva Vany , Arruda Maria Augusta B , Freitas Marta S , Plotkowski Maria Cristina , Cunha Fernando Q , Barja-Fidalgo Christina
Published: January 2018

Intravenous administration of lipopolysaccharide (LPS) to rats increased the production of nitric oxide (NO) metabolites (NOx) by blood polymorphonuclear neutrophils (PMN) in vitro. Both dexamethasone and L-NMMA, added in vitro to neutrophil cultures, inhibited the production of NO. On the other hand, the production of NO was not affected by the treatment, in vivo or in vitro, with different inhibitors of cyclooxygenase or 5-lipoxygenase or with a platelet-activating factor (PAF) antagonist. The incubation of blood PMN from normal rats in vitro with neutrophil activators (PAF, leukotriene B4, and interleukin-8) and different cytokines [interleukin-1, tumor necrosis factor α, and interferon-γ (IFN-γ)] showed that only IFN-γ was able to induce the production of high amounts of NO. This induction was directly correlated with the expression of iNOS and an increase in in the enzyme activity in blood PMN. The tyrosine kinase inhibitor genistein inhibited NO production induced by IFN-γ, suggesting that the signal transduction pathway leading to NOS induction in rat PMN involves phosphorylation by tyrosine kinase. We also showed that NO produced by IFN-γ activated rat blood PMN involved in the killing of Pseudomonas aeruginosa. J. Leukoc. Biol. 65: 508–514; 1999.
Cbl functions downstream of Src kinases in FCγRI signaling in primary human macrophages
Authors: Erdreich-Epstein Anat , Liu Ming , Kant Anita M , Izadi Kayvon D , Nolta Jan A , Durden Donald L
Published: January 2018

Cbl is a cytosolic protein that is rapidly tyrosine phosphorylated in response to Fc receptor activation and binds to the adaptor proteins Grb2, CrkL, and Nck. A few reports describe Cbl interactions in primary human hematopoietic cells. We show evidence that Cbl participates in signaling initiated by FcγRI receptor cross-linking in human primary macrophages, and functions downstream of Src family kinases in this pathway. FcγRI stimulation in human macrophages was associated with rapid and transient tyrosine phosphorylation of the Cbl adaptor protein. Immunoprecipitated Cbl was complexed with several tyrosine phosphorylated proteins, the most prominent of which was a 38-kDa band identified as the CrkL adaptor protein. CrkL associated with tyrosine-phosphorylated Cbl and itself became tyrosine phosphorylated after FcγRI cross-linking. SLP-76, a recently cloned Grb2-associated protein, was strongly tyrosine phosphorylated after FcγRI stimulation and was associated with both Cbl and Grb2. Grb2 and Cbl binding to SLP-76 were inducible after FcγRI stimulation of the macrophages. Nck was inducibly bound to Cbl after FcγRI stimulation, whereas Grb2 was constitutively associated with it. Shc was also inducibly tyrosine phosphorylated and bound to Grb2 after FcγRI stimulation of the macrophages. PP1, a specific inhibitor of Src kinases, inhibited the FcγRI-induced respiratory burst, as well as the tyrosine phosphorylation of Cbl and its inducible association with CrkL. These results suggest a fundamental role for the tyrosine phosphorylation of Cbl, CrkL, SLP-76, and Shc and the association of Cbl with CrkL, SLP-76, and Nck in FcγRI signaling in human macrophages. Experiments performed with PP1, the specific Src kinase inhibitor, demonstrate the first evidence that Cbl and the Cbl-Crkl interaction are downstream targets for myeloid Src kinases required for the activation of myeloid NADPH oxidase activity. J. Leukoc. Biol. 65:523–534; 1999.
The taming of IL-12: suppressing the production of proinflammatory cytokines
Authors: Sutterwala Fayyaz S , Mosser David M
Published: January 2018

Interleukin (IL)-12 is a cytokine that possesses both proinflammatory and immunoregulatory activity. IL-12, and the interferon-γ (IFN-γ) that is induced by IL-12, play central roles in the development of the Th1-type immune responses that are required for immunity to intracellular pathogens. Recently a number of these pathogens, including Leishmania, measles virus, and human immunodeficiency virus (HIV), have been shown to subvert the development of cell-mediated immunity by actively inhibiting the production of IL-12. Similarly, the ligation of phagocytic receptors on macrophages has also been shown to suppress IL-12 production. The suppression of IL-12 production by receptor ligation occurs by at least two distinct mechanisms: one involves a direct inhibition of gene transcription and the other depends on the production of inhibitory cytokines. We review studies in which IL-12 has been experimentally manipulated, and we compare the mechanisms by which this regulation can occur. Because the IL-12 that is produced during acute inflammation and chronic autoimmune disorders can lead to exacerbated disease, the development of pharmacological means to suppress IL-12 production is currently under investigation. This review focuses on the production of IL-12 by antigen-presenting cells and the methods by which the down-regulation of IL-12 production can be exploited either by pathogens or for therapeutic ends. J. Leukoc. Biol. 65: 543–551; 1999.
Morphine modulation of peritoneal inflammation in Atlantic salmon and CB6 mice
Authors: Chadzinska M , Kolaczkowska E , Seljelid R , Plytycz B
Published: January 2018

Peritoneal inflammation is a convenient model for comparisons of modulatory effects of morphine in phylogenetically distant vertebrates. Both in salmon and mice morphine injected intraperitoneally together with an irritant (thioglycollate) significantly inhibits inflammation as estimated by the number of peritoneal leukocytes. The low number of exudate cells in morphine-treated animals seems to be compensated by their high activity, as evidenced by the enhanced phorbol myristate acetate-induced respiratory burst. The morphine-inhibited influx of leukocytes into the irritated peritoneal cavity correlates with the morphine-lowered level of plasma chemotactic factors both in fish and mice. It implies that morphine impairs the level of plasma chemotactic factor either directly (affecting their release from the resident peritoneal cells) or indirectly (decreasing the number of inflammatory leukocytes by inhibition of their migration from hemopoietic sites). The inhibitory effects of morphine on both the cell number and chemoattractant level are completely reversed by the naltrexone pretreatment, which implicates the involvement of opioid receptors. J. Leukoc. Biol. 65: 590–596; 1999.
Influenza A virus up-regulates neutrophil adhesion molecules and adhesion to biological surfaces
Authors: Hartshorn Kevan L , White Mitchell R
Published: January 2018

Influenza A virus (IAV) binds to sialylated neutrophil surface components (e.g., CD43 and sialyl Lewisx antigen) and induces both activation and functional depression of neutrophils. We report that IAV enhanced neutrophil adhesion to surfaces coated with serum or serum components, but not to uncoated plastic. IAV up-regulated expression of integrins (CD11b and CD11c) and carcinoembryonic-related antigens on neutrophils, while reducing expression of CD43, L-selectin, and P-selectin glycoprotein ligand (PSGL). Although treatment of neutrophils with elastase or O-sialoglycoprotease decreased surface CD43 and PSGL, they did not reduce binding of IAV to neutrophils, implying that IAV can bind to alternate binding sites in the absence of CD43. Pretreatment of neutrophils with elastase also did not prevent IAV from increasing expression of integrins and enhancing adhesion. Up-regulation of adhesion molecules and adhesion are important, previously unrecognized, features of neutrophil activation by IAV. Further studies will be needed to clarify the mechanism of these effects. J. Leukoc. Biol. 65: 614–622; 1999.
Role of cytokines in epidermal Langerhans cell migration
Authors: Wang Binghe , Amerio Paolo , Sauder Daniel N
Published: January 2018

In the epidermal compartment of skin, keratinocytes (KC), Langerhans cells (LC), and their soluble products, i.e. cytokines, constitute a unique immunologic microenvironment. KC participate in cutaneous immune responses by producing various cytokines. LC, a member of the dendritic cell (DC) family, represent the professional antigen-presenting cells in the epidermis. Although it has been demonstrated that migration of LC from skin to lymph nodes is a critical step for the antigen presentation, molecular mechanisms for such an event remain unclear. Recent studies suggest that cytokines are able to modulate LC/DC migration. There is accumulating evidence that proinflammatory cytokines including interleukin (IL)-1 and tumor necrosis factor a promote LC emigration from the skin, whereas the anti-inflammatory cytokine IL-10 is a counter-regulator. LC/DC express chemokine receptors. Chemokines generated from lymphatic endothelial cells and lymph node cells play a role in the directional migration of LC/DC into lymph nodes. This article reviews current studies on the role of cytokines in LC/DC migration. J. Leukoc. Biol. 66: 33–39; 1999.
Interleukin-18 synthesis and secretion by dendritic cells are modulated by interaction with antigen-specific T cells
Authors: Gardella Stefania , Andrei Cristina , Costigliolo Sara , Poggi Alessandro , Zocchi M Raffaella , Rubartelli Anna
Published: January 2018

We show that interleukin-18 is constitutively produced by dendritic cells; synthesis and secretion are poorly affected by maturative stimuli. Challenge of dendritic cells with autologous antitetanus toxoid T lymphocytes results in a secretory switch, with induction of secretion of biologically active interleukin-18 and decrease of its intracellular content. Similarly, when dendritic cells are challenged with allospecific T cells a dramatic decrease of intracellular interleukin-18 content occurs, whereas no effects are observed after co-culture with autologous activated T cells. The induction of secretion can be mediated by engagement of CD40 on dendritic cells, as indicated by the increased amount of interleukin-18 in dendritic cell supernatants after CD40 triggering by anti-CD40 antibodies. However, CD40 engagement, unlike from antigen-specific T cells, does not result in reduced intracellular interleukin-18 content, suggesting that this decrease may be mediated by structure(s) involved in antigen recognition. J. Leukoc. Biol. 66: 237–241; 1999.
Role of antigen-presenting cells in cross-priming of cytotoxic T lymphocytes by apoptotic cells
Authors: Ronchetti Anna , Iezzi Giandomenica , Crosti Maria Cristina , Garancini Maria Paola , Protti Maria Pia , Bellone Matteo
Published: January 2018

Although the mechanisms regulating recognition and phagocytosis of apoptotic cells by scavenger cells are the subject of intense investigation, little is known about the fate of the antigens contained in apoptotic cells and the constraints defining their immunogenicity. We developed a model in C57BL/6 mice to evaluate whether phagocytosis of apoptotic tumor cells yielded antigens able to get access to the MHC class I pathway and activate a specific cytotoxic T lymphocyte response. Our results demonstrate that apoptotic tumor cells are antigenic in vitro and can be immunogenic in vivo. Their immunogenicity depends on the number of cells used for immunization and the antigen-presenting cells involved in processing and presentation of antigens contained in the dying cells. The demonstration of the immunogenicity of apoptotic cells may have direct implications both in autoimmunity and cancer. J. Leukoc. Biol. 66: 247–251; 1999.
The role of dendritic cells in T cell selection and survival
Authors: Brocker Thomas
Published: January 2018

Dendritic cells (DC) not only play an important role in the induction of immunity, but also have major functions in thymus and periphery in the absence of nominal antigen. In order to study these and other DC-functions in vivo, we expressed MHC class II I-E molecules under the control of the DC-specific CD11c promoter in C57Bl/6 mice. With this targeted expression we were able to investigate DC functions in vivo without further manipulation of DC. We describe our findings with respect to the two major thymic events of negative and positive selection and demonstrate that DC are able and sufficient to induce negative selection of autoreactive CD4+ thymocytes by clonal deletion but do not induce positive selection. We further demonstrate in thymus-transplant experiments that DC play a major role in inducing survival of peripheral CD4+ mature T cells. This transgenic model therefore seems to be a valuable tool for the investigation of DC functions in vivo. J. Leukoc. Biol. 66: 331–335; 1999.
IL-6 knock-out mice exhibit resistance to splanchnic artery occlusion shock
Authors: Cuzzocrea Salvatore , De Sarro Giovambattista , Costantino Giuseppina , Ciliberto Gennaro , Mazzon Emanuela , De Sarro Angela , Caputi Achille P
Published: January 2018

We used IL-6 knock-out (KO) mice to evaluate a possible role for IL-6 in the pathogenesis of splanchnic artery occlusion shock (SAO). SAO shock was induced by clamping both the superior mesenteric artery and the celiac trunk, followed by release of the clamp. There was a marked increase in the peroxynitrite formation in the plasma of the SAO-shocked IL-6 wild-type (WT) mice after reperfusion. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine in the necrotic ileum in shocked IL-6 WT mice. SAO-shocked WT mice developed a significant increase of tissue myeloperoxidase (MPO) and malondialdehyde (MDA) activity and marked histological injury to the distal ileum. SAO shock was also associated with a significant mortality (0% survival). Reperfused ileum tissue sections from SAO-shocked WT mice showed positive staining for P-selectin. Little specific staining was observed in sham-WT mice. Staining of ileum tissue obtained from sham-operated WT mice with anti-ICAM-1 antibody showed weak but diffuse staining, demonstrating that ICAM-1 is constitutively expressed. However, after SAO shock the staining intensity increased substantially in the ileum section from WT mice. Intensity and degree of P-selectin and ICAM-1 were markedly reduced in tissue section from SAO-shocked IL-6 KO mice. SAO-shocked IL-6 KO mice also show significant reduction of neutrophil infiltration into the reperfused intestine, as evidenced by reduced MPO activity, improved histological status of the reperfused tissues, reduced peroxynitrite formation, reduced MDA levels, and improved survival. In vivo treatment with anti-IL-6 significantly prevents the inflammatory process. Our results clearly demonstrate that IL-6 plays an important role in ischemia and reperfusion injury and allows the hypothesis that inhibition of IL-6 may represent a novel and possible strategy. Part of this effect may be due to inhibition of the expression of adhesion molecules and subsequent reduction of neutrophil-mediated cellular injury. J. Leukoc. Biol. 66: 471–480; 1999.
Attenuated liver fibrosis and depressed serum albumin levels in carbon tetrachloride-treated IL-6-deficient mice
Authors: Natsume Miyoko , Tsuji Hirokazu , Harada Akihisa , Akiyama Mariko , Yano Tomoyuki , Ishikura Hiroshi , Nakanishi Isao , Matsushima Kouji , Kaneko Shu-ichi , Mukaida Naofumi
Published: January 2018

Chronic intermittent injection of carbon tetrachloride (CCI4) for more than 10 weeks induced liver fibrosis in mice, as evidenced by positive Azan staining and increased intrahepatic collagen content. Preceding the onset of liver fibrosis, interleukin-6 (IL-6) gene expression was enhanced in liver and immunoreactive IL-6 was detected in infiltrating inflammatory cells. To delineate the role of IL-6 in this process, we treated IL-6-deficient mice with CCl4 in a similar manner for 12 weeks, after which fibrotic changes were less evident and serum albumin levels were lower in IL-6-deficient than wild-type mice. Moreover, CCl4-induced expression of transforming growth factor β1 and hepatocyte growth factor genes in liver was significantly reduced in IL-6-deficient mice. Thus, IL-6 may be vitally involved in fibrotic changes and maintenance of serum albumin levels, partly by modulating intrahepatic expression of these cytokines. J. Leukoc. Biol. 66: 601–608; 1999.
A phagocytic challenge with IgG-coated erythrocytes depresses macrophage respiratory burst and phagocytic function by different mechanisms
Authors: Raley Michael J , Lennartz Michelle R , Loegering Daniel J
Published: January 2018

A phagocytic challenge with IgG-coated erythrocytes (EIgG) previously has been shown to cause impaired macrophage respiratory burst capacity and FcγR-mediated phagocytic function. Because both the respiratory burst and FcγR-mediated phagocytosis are dependent on the release of arachidonate (AA), we evaluated the effects of impaired AA release on the depression of macrophage function caused by a phagocytic challenge. Challenge with EIgG caused a depression of A23187-stimulated AA release that was associated with impaired phorbol myristate acetate (PMA)-stimulated H2O2 production and FcγR-mediated phagocytic function. In contrast, challenge with IgG-coated glass beads (BIgG) had no effect on either AA release or H2O2 production but did depress phagocytic function. Exogenous AA prevented the depression of H2O2 production but had no effect on phagocytic function. Phospholipase A2 (PLA2) activity was depressed under conditions where AA release was impaired. The depression of phagocytic function was correlated with a depression of both EIgG binding and FcγR expression. Thus, a phagocytic challenge with EIgG results in macrophage dysfunction by depressing PLA2 activity and depleting FcγR. J. Leukoc. Biol. 66: 803–808; 1999.
Internalization of FimH+ Escherichia coli by the human mast cell line (HMC-1 5C6) involves protein kinase C
Authors: Lin Tong-Jun , Gao Zhimin , Arock Michel , Abraham Soman N
Published: January 2018

Rodent mast cells (MC) play critical roles in host defense against bacterial infection. However, bacteria-mediated signaling mechanisms in MC have not been studied. In addition, the response of human MC to bacteria is not fully investigated. This study examined the interaction between human MC and type 1 fimbriated Escherichia coli and the mechanisms involved using the human MC line HMC-1 5C6 and human cord blood-derived MC. These MC internalized significant numbers of FimH+  E. coli, but not its isogenic FimH− mutant. In HMC-1 cells, bacterial internalization was stimulated by protein kinase C (PKC) activation [short-term phorbol myristate acetate (PMA) treatment] and dramatically decreased by PKC inhibitors or PKC depletion (long-term PMA treatment). Moreover, bacterial internalization was accompanied by significant expression of PKCβ1 and δ. Fluorescence microscopy demonstrated accumulation of PKCβ1 on internalized bacteria. These data indicate that human MC has the capacity to internalize bacteria and PKC may be a critical intracellular mediator of this function. J. Leukoc. Biol. 66: 1031–1038; 1999.
Regulation of intercellular adhesion molecule-1 (CD54) gene expression
Authors: Roebuck Kenneth A , Finnegan Alison
Published: January 2018

Intercellular adhesion molecule-1 (ICAM-1, CD54) is an inducible cell adhesion glycoprotein of the immunoglobulin supergene family expressed on the surface of a wide variety of cell types. ICAM-1 interactions with the β2 integrins CD11a/CD18 (LFA-1) and CD11b/CD18 (MAC-1) on the surface of leukocytes are important for their transendothelial migration to sites of inflammation and their function as costimulatory molecules for T cell activation. ICAM-1 is constitutively expressed on the cell surface and is up-regulated in response to a variety of inflammatory mediators, including proinflammatory cytokines, hormones, cellular stresses, and virus infection. These stimuli increase ICAM-1 expression primarily through activation of ICAM-1 gene transcription. During the past decade much has been learned about the cell type- and stimulus-specific transcription of ICAM-1. The architecture of the ICAM-1 promoter is complex, containing a large number of binding sites for inducible transcription factors, the most important of which is nuclear factor-kappa B (NF-κB). NF-κB acts in concert with other transcription factors and co-activators via specific protein-protein interactions, which facilitate the assembly of distinct stereo-specific transcription complexes on the ICAM-1 promoter. These transcription complexes presumably mediate the induction of ICAM-1 expression in different cell types and in response to different stimuli. In this review, we summarize our current understanding of ICAM-1 gene regulation with a particular emphasis on the transcription factors and signal transduction pathways critical for the cell type- and stimulus-specific activation of ICAM-1 gene transcription. J. Leukoc. Biol. 66: 876–888; 1999.
The tumorigenic and angiogenic effects of MGSA/GRO proteins in melanoma
Authors: Haghnegahdar Hamid , Du Jianguo , Wang DingZhi , Strieter Robert M , Burdick Marie D , Nanney Lillian B , Cardwell Nancy , Luan Jing , Shattuck-Brandt Rebecca , Richmond Ann
Published: January 2018

Continuous expression of the MGSA/GROα, β, or γ chemokine bestows tumor-forming capacity to the immortalized murine melanocyte cell line, melan-a. The mechanism for this transformation is unclear, although both autocrine and paracrine processes are possible because melan-a cells as well as endothelial cells express a low level of the receptor for this ligand. To further define the role of MGSA/GRO proteins in melanocyte transformation, two types of experiments were designed to neutralize the biological effects of MGSA/GRO in the transfected melan-a clones: (1) the effect of neutralizing antiserum to MGSA/GRO proteins on melan-a tumor growth was assessed; (2) the tumor-forming capacity of melan-a clones expressing ELR motif-mutated forms of MGSA/GRO with compromised receptor affinity was compared to the tumor-forming capacity of clones expressing wild-type MGSA/GRO. These experiments revealed that SCID mice inoculated with MGSA/GROα- or γ-expressing melan-a cells and subsequently treated with antiserum to the respective chemokine exhibited decreased tumor growth. This reduction in tumor growth was accompanied by declining angiogenic activity in MGSA/GROγ-expressing tumors. Moreover, athymic nude mice injected with melan-a cells expressing ELR-mutant forms of MGSA/GROα exhibited markedly impaired tumor-forming capacity compared with those mice injected with melan-a clones expressing wild-type MGSA/GRO. These data suggest that continuous expression of MGSA/GRO proteins may facilitate tumor growth by stimulating the growth of microvessels into the tumor (paracrine) and by affecting melanocyte growth (autocrine). J. Leukoc. Biol. 67: 53–62; 2000.
Langerhans cells acquire a CD8+ dendritic cell phenotype on maturation by CD40 ligation
Authors: Anjuere Fabienne , del Hoyo Gloria Martínez , Martín Pilar , Ardavín Carlos
Published: January 2018

Dendritic cell (DC) reconstitution experiments and phenotypic analysis of DC subpopu-lations have allowed the definition in the mouse of two main DC categories: CD8+ lymphoid DCs and CD8− myeloid DCs. With regard to Langerhans cells (LCs), which represent immature DCs differentiating into mature DCs on migration to the lymph nodes after an antigenic stimulation, although classically considered as myeloid DCs, there is no experimental evidence of their origin. It has been recently shown that mouse LCs, negative for CD8 and LFA-1, undergo CD8/LFA-1 up-regulation on migration, suggesting that LCs belong to the CD8+ lymphoid DC lineage. To further reinforce this hypothesis, we have analyzed the modulation of CD8 expression by LCs on culture with molecules known to induce LC maturation. Our results show that LC acquired a CD8+ lymphoid phenotype on CD40 ligation. J. Leukoc. Biol. 67: 206–209; 2000.
P47phox-deficient NADPH oxidase defect in neutrophils of diabetic mouse strains, C57BL/6J-m db/db and dbl+
Authors: Huang Chi-Kuang , Zhan Lijun , Hannigan Michael O , Ai Youxi , Leto Thomas L
Published: January 2018

Deficiencies in neutrophil NADPH oxidase proteins have been demonstrated in humans with chronic granulomatous disease. However, no spontaneous mutation in murine NADPH oxidase has been reported. In this study we report that neutrophils from the diabetic mouse strains, C57BL/6J-m heterozygous lean (leprdb/+) and homozygous obese (leprdb/db) mice produced no superoxide on stimulation. An absence of intact p47phox but not other oxidase proteins was observed in both mouse strains through the use of immunoblotting. Molecular analysis by reverse transcriptase-polymerase chain reaction identified three abnormal p47phox mRNA transcripts. Sequencing of genomic DNA of p47phox revealed a point mutation at the –2 position of exon 8, which is consistent with aberrant splicing of the p47phox transcript. These results indicate that the C57BL/6J-m db/db and db/+ mice are the first spontaneously derived murine model of NADPH oxidase deficiency involving a p47phox mutation. J. Leukoc. Biol. 67: 210–215; 2000.
Gender difference in cell-mediated immunity after thermal injury is mediated, in part, by elevated levels of interleukin-6
Authors: Gregory Meredith S , Faunce Douglas E , Duffner Lisa A , Kovacs Elizabeth J
Published: January 2018

The gender difference in normal immune function has been well documented, however, there is only limited information regarding whether such a difference occurs after injury. To investigate this, we examined cell-mediated immune responses in male and female mice given a 15% total body surface area dorsal scald or sham injury. Both delayed-type hypersensitivity (DTH) and splenocyte proliferative responses were significantly suppressed in males at 1 day and in females at 7 and 10 days post burn (P < 0.01). The decreased splenocyte proliferation was found to be macrophagedependent and suppression of both immune parameters corresponded with elevated interleukin-6 (IL-6) levels. Furthermore, post-burn treatment with an anti-IL-6 antibody partially restored the DTH response in males at 1 day and females at 10 days post injury and completely restored splenocyte proliferation. These data demonstrate a possible mechanism for the gender difference in cell-mediated immune responses after thermal injury. J. Leukoc. Biol. 67: 319–326; 2000.