bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphine enhances interleukin-12 and the production of other pro-inflammatory cytokines in mouse peritoneal macrophages
Authors: Peng Xiaohui , Mosser David M , Adler Martin W , Rogers Thomas J , Meissler Joseph J , Eisenstein Toby K 
Published: September 2022

Abstract
In this study we investigated the capacity of morphine to modulate expression of cytokines in peritoneal macrophages. Mice were implanted subcutaneously with a 75-mg morphine slow-release pellet, and 48 h later resident peritoneal macrophages were harvested. Control groups received placebo pellets, naltrexone pellets, or morphine plus naltrexone pellets. Adherent cells were stimulated with lipopolysaccharide (LPS: 10 μg/mL) plus interferon-γ (IFN-γ: 100 units/mL) to induce cytokine production. After 24 h RNA was extracted for analysis of cytokine mRNA levels by reverse transcriptase-polymerase chain reaction, or supernatants were collected after 48 h for determination of cytokine production by enzyme-linked immunosorbent assay (ELISA). Morphine enhanced mRNA expression of interleukin (IL)-12 p40 and tumor necrosis factor α (TNF-α) compared with controls, whereas IL-10 levels were unchanged by drug treatment. ELISA data showed that both IL-12 p40 and p70 were increased by morphine. The enhancement of IL-12 at both the mRNA and protein levels was antagonized by naltrexone, indicating that the modulation of this cytokine by morphine is via a classic opioid receptor. These results are particularly interesting in light of our previous observation that 48 h after morphine pellet implantation, the peritoneal cavity is colonized with gram-negative and other enteric bacteria. The enhancement of IL-12 by morphine might be related to morphine-induced sepsis.
Identification of the Ly49L protein: evidence for activating counterparts to inhibitory Ly49 proteins
Authors: Makrigiannis Andrew P , Etzler Jessica , Winkler-Pickett Robin , Mason Anna , Ortaldo John R , Anderson Stephen K 
Published: September 2022

Abstract
Previous studies have indicated that NK cells from different strains of inbred mice may express distinct Ly49 repertoires. Screening of NK cells from the CBA/J mouse for inhibitory and activating Ly49s revealed a novel DAP12-associated receptor that was immunoprecipitated with the Ly49G-specific mAb 4D11. Degenerate primers were designed to amplify and clone Ly49 cDNAs from CBA/J NK cells. A novel activating Ly49 cDNA was identified, which bears strong homology to the partially sequencedLy49l gene found in C57BL/6 mice. Transfection ofLy49l into a DAP12+ cell line and subsequent immunoprecipitation experiments showed that Ly49L is likely the activating Ly49 detected by the 4D11 antibody in CBA/J NK cells. Antibody-mediated cross-linking of Ly49L induced DAP12 phosphorylation, providing evidence that Ly49L is a functional activating receptor. Comparison of the extracellular domains of Ly49 family members indicates that all known activating members have an inhibitory counterpart with a highly related extracellular region.
Mono Mac 1: a new in vitro model system to study HIV-1 infection in human cells of the mononuclear phagocyte series
Authors: Genois Nicolas , Robichaud Gilles A , Tremblay Michel J 
Published: September 2022

Abstract
Throughout the years, most researchers have used continuous cell lines as in vitro models to evaluate the immunopathogenesis of human immunodeficiency virus type-1 (HIV-1) infection. Unfortunately, the most commonly used monocytoid malignant cells have not been shown to adequately mimic primary human monocyte-derived macrophages, at least with respect to HIV-1 infection. The Mono Mac 1 cell line has been defined as a model system for studying biochemical, immunological, and genetic functions of human cells of the monocyte/macrophage lineage. In this study, we have investigated whether Mono Mac 1 represents an in vitro culture system for HIV-1 infection. Flow cytometric analyses revealed that Mono Mac 1 are positive for the HIV-1 primary receptor (CD4), as well as for the coreceptors (CXCR4, CCR5, and CCR3). Infectivity experiments conducted with recombinant luciferase-encoding and fully infectious viruses demonstrated that Mono Mac 1 can support a highly productive infection with both macrophage- and dual-tropic isolates of HIV-1. Furthermore, differentiation of such cells led to a marked increase in virus production. Data from semiquantitative polymerase chain reaction analysis and mobility shift assays indicated that enhanced virus production in differentiated Mono Mac 1 cells was most likely related to an increase in nuclear translocation of NF-κB. Mono Mac 1 can thus be considered as a human monocytoid cell line representing a proper in vitro system for studying the complex interactions between HIV-1 and cells of the monocyte/macrophage lineage.
Streptolysin O-permeabilized granulocytes shed L-selectin concomitantly with ceramide generation via neutral sphingomyelinase
Authors: Walev Iwan , Tappe Dennis , Gulbins Erich , Bhakdi Sucharit 
Published: September 2022

Abstract
Cleavage of membrane-associated L-selectin regulates leukocyte rolling on vascular endothelium at sites of inflammation. We report that rapid and massive shedding of L-selectin occurs from granulocytes attacked by the pore-forming bacterial toxin streptolysin O (SLO). Shedding was not induced by an SLO mutant that retained binding capacity but lacked pore-forming activity. Cells permeabilized with SLO exhibited a 1.5-fold increase in the activity of neutral sphingomyelinase, which was accompanied by increased ceramide formation. L-selectin cleavage was inducible by treatment of cells with bacterial sphingomyelinase, and also through exogenous application of a cell-permeable ceramide analog. Our data identify a novel path to the shedding process and show that activation of neutral sphingomyelinase with the generation of ceramide is an important event underlying enhanced sheddase function in cells permeabilized by a pore-forming toxin.
Role of IL-12 in macrophage activation during intracellular infection: IL-12 and mycobacteria synergistically release TNF-α and nitric oxide from macrophages via IFN-γ induction
Authors: Xing Zhou , Zganiacz Anna , Santosuosso Micheal 
Published: September 2022

AbstractIL-12 is believed to play an important role in cell-mediated immunity against intracellular infection primarily by acting on T and NK cells. Recent evidence has suggested, however, that IL-12 has broader cellular targets than previously thought. In this study, we examined the role of IL-12 in macrophage TNF-α and nitric oxide (NO) release by using anin vitro model of intracellular infection. IL-12 alone released relatively little TNF-α and NO, whereas live mycobacteria alone released TNF-α markedly but little NO from murine alveolar macrophages. However, IL-12 and mycobacteria together enhanced TNF-α and NO release synergistically. Because IL-12 and mycobacteria also released IFN-γ from macrophages synergistically, and exogenous IFN-γ with mycobacteria enhanced TNF-α and NO release synergistically, we examined the role of endogenous IFN-γ in IL-12/mycobacteria-stimulated macrophage activation. Using macrophages from mice deficient in IFN-γ, we found that IL-12/mycobacteria-enhanced macrophage TNF-α and NO release was mediated through endogenous IFN-γ. We further demonstrated that IFN-γ and mycobacteria together had a selective effect on macrophage cytokine release because they released TNF-α synergistically but not macrophage chemotactic protein-1 (MCP-1). These findings reveal that IL-12 can activate macrophages potently during intracellular infection, and this activating effect is mediated primarily through its effect on macrophage IFN-γ release.
Protein kinase C agonists enhance phagocytosis ofP. aeruginosaby murine alveolar macrophages
Authors: Heale John-Paul , Speert David P 
Published: September 2022

AbstractPulmonary alveolar macrophages (AMφs) are incompetent to phagocytose unopsonized Pseudomonas aeruginosa, but ingestion by other macrophage phenotypes (i.e., peritoneal macrophages) occurs efficiently. The purpose of this study was to explore factors that might control such phenotypic differences. Our laboratory has demonstrated that AMφs exposed to sodium azide display enhanced phagocytosis of P. aeruginosa. Here we report that the phagocytic-enhancing effect of sodium azide was abrogated by inhibitors of protein kinase C (PKC). Furthermore, the addition of PKC agonists, such as phorbol myristate acetate (PMA), and tumor necrosis factor α (TNF-α), mimicked the phagocytic enhancing effect of sodium azide. We conclude that AMφs are normally incompetent to phagocytose P. aeruginosa. Factors that up-regulate AMφ function (azide, PMA, TNF-α) can reverse the phagocytic incompetence in vitro. Although these compounds are not appropriate candidate therapeutic agents, their effects provide insights for understanding of the pathways responsible for regulation of P. aeruginosa phagocytosis.
Neutrophil survival is markedly reduced by incubation with influenza virus andStreptococcus pneumoniae: role of respiratory burst
Authors: Engelich Georg , White Mitchell , Hartshorn Kevan L 
Published: September 2022

AbstractBacterial superinfections are an important cause of morbidity and mortality during influenza A virus (IAV) epidemics. We demonstrate that incubation with the combination of IAV and Streptococcus pneumoniae caused marked reductions in survival of neutrophils in vitro compared with treatment with control buffer or IAV or S. pneumoniae alone. This cooperative effect was in part mediated by acceleration of neutrophil apoptosis as evidenced by increases in annexin-V binding and caspase-3 activation. However, GM-CSF did not increase survival of neutrophils exposed to IAV and S. pneumoniae. IAV enhanced neutrophil uptake of S. pneumoniae significantly. Furthermore, the combination of IAV and S. pneumoniae caused significantly more hydrogen peroxide production than IAV or S. pneumoniae alone. This increased respiratory burst activity contributed to the diminished neutrophil survival caused by IAV and S. pneumoniae. The NADPH oxidase inhibitor, diphenyleneiodonium, significantly improved survival of neutrophils treated with IAV and S. pneumoniae. These findings may help to explain the increased susceptibility of IAV-infected patients to infections with S. pneumoniae.
Adjuvant effect of γ-inulin is mediated by C3 fragments deposited on antigen-presenting cells
Authors: Kerekes Krisztina , Cooper Peter D , Prechl József , Józsi Mihály , Bajtay Zsuzsa , Erdei Anna 
Published: September 2022

AbstractThe adjuvant effect of γ-inulin, a strong activator of the alternative complement pathway, is well-known, but its exact mechanism is not revealed yet. Here, we show that macrophages, isolated from the peritoneal cavity of γ-inulin-injected mice and used as antigen-presenting cells, enhance the proliferation of antigen-specific T-cells up to 2.5-fold when compared with macrophages of nontreated animals. This effect is abrogated by the presence of anti-C3 F(ab′)2 fragments and by prior decomplementation of the donor animals with CVF. It is demonstrated that treatment of mice with the adjuvant results in deposition of C3-fragments onto the surface of peritoneal macrophages, as does in vitro incubation of the cells with γ-inulin in the presence of fresh autologous serum. Prior incubation of macrophages with γ-inulin plus serum in vitro enhances subsequent C3 production. Because it has been shown earlier that CR1/2 expressed on activated T-cells and interacting with covalently bound C3-fragments plays an important role in the augmentation of the adaptive response, our present results reveal a mechanism that contributes to the adjuvant effect of γ-inulin and point to a further link between innate and adaptive immunity.
Natural and synthetic agonists of the melanocortin receptor type 3 possess anti-inflammatory properties
Authors: Getting Stephen J , Allcock Graham H , Flower Roderick , Perretti Mauro 
Published: September 2022

AbstractThe effects of the natural and synthetic ligands for the melanocortin receptor type 3 (MC3-R) have been evaluated in a murine model of experimental gout. Systemic treatment of mice with γ2-melanocyte-stimulating hormone (γ2-MSH) and the synthetic agonist MTII inhibited accumulation of KC, interleukin-1 beta (IL-1β), and PMN elicited by urate crystals in the peritoneal cavity. In vitro, macrophage (Mø) activation, determined as release of KC and IL-1β, was inhibited by γ2-MSH and MTII. The mixed MC3/4-R antagonist SHU9119 prevented the inhibitory actions of γ2-MSH and MTII in vitro and in vivo, whereas the selective MC4-R antagonist HS024 was without effect. Western blotting also showed the presence of MC3-R protein on murine peritoneal Mø. Furthermore, agonism at the MC3-R evoked accumulation of cAMP within the Mø, which was inhibited by SHU9119. Thus, naturally occurring melanocortins, as well as the synthetic long-acting compound MTII, activate MC3-R on peritoneal Mø to inhibit the experimental inflammatory response.
More than destructive: neutrophil-derived serine proteases in cytokine bioactivity control
Authors: Bank Ute , Ansorge Siegfried 
Published: September 2022

AbstractIn addition to the mechanisms inducing the expression and secretion of cytokines under distinct pathophysiological conditions, the fate of cytokines after secretion at sites of inflammation is a field of growing interest. Proteolysis has been suggested to be a fundamental mechanism of regulating the activities of various components of the cytokine network. Evidence grows that besides highly specific cytokine converting proteases such as interleukin-1β-converting enzyme or tumor necrosis factor-converting enzyme, neutrophil-derived serine proteases are intimately involved in the modulation of the activities of cytokines and their receptors. Particularly at sites of inflammation, high amounts of the active serine proteases elastase, cathepsin G, and proteinase 3 are released from infiltrating polymorphonuclear cells in close temporal correlation to elevated levels of inflammatory cytokines, strongly indicating that these proteases are involved in the control of cytokine bioactivity and availability.
Increase of CCR1 and CCR5 expression and enhanced functional response to MIP-1α during differentiation of human monocytes to macrophages
Authors: Kaufmann Andreas , Salentin Robert , Gemsa Diethard , Sprenger Hans 
Published: September 2022

AbstractChemokines and their receptors regulate migration of leukocytes under normal and inflammatory conditions. In this study, we analyzed the CC chemokine receptor (CCR) expression of monocytes differentiatingin vitro to macrophages. We observed a time-dependent change of expression and functional responsiveness of CCR1, CCR2, and CCR5 within 48 h. Whereas freshly harvested monocytes were strongly attracted by monocyte chemotactic protein 1 (MCP-1), a specific ligand for CCR2, only a weak response was observed to macrophage inflammatory protein 1α (MIP-1α), which binds to CCR1 and CCR5. In striking contrast, differentiated macrophages displayed a strong chemotactic response to MIP-1α and only a weak response to MCP-1. These findings were paralleled by intracellular calcium shifts. During the time course of monocyte to macrophage differentiation, mRNA levels and surface expression of CCR2 decreased, whereas that of CCR1 and CCR5 increased. The time-dependent switch from CCR2 on monocytes to CCR1 and CCR5 on mature macrophages reflects a functional change belonging to the differentiation process of monocytes to macrophages and may form the basis for a differential responsiveness of monocytes and macrophages to distinct sets of chemokines.
Involvement of protein kinases in the potentiation of lipopolysaccharide-induced inflammatory mediator formation by thapsigargin in peritoneal macrophages
Authors: Chen Bing-Chang , Hsieh Shie-Liang , Lin Wan-Wan 
Published: September 2022

AbstractWe have explored the regulatory roles played by Ca2+-dependent signaling on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6) release in mouse peritoneal macrophages. To elevate intracellular Ca2+, we used thapsigargin (TG) and UTP. Although LPS alone cannot stimulate NO synthesis, co-addition with TG, which sustainably increased [Ca2+]i, resulted in NO release. UTP, via acting on P2Y6 receptors, can stimulate phosphoinositide (PI) turnover and transient [Ca2+]i increase, however, it did not possess the NO priming effect. LPS alone triggered the release of PGE2, TNF-α, and IL-6; all of which were potentiated by the presence of TG, but not of UTP. The stimulatory effect of LPS plus TG on NO release was inhibited by the presence of Ro 31-8220, Go6976, KN-93, PD 098059, or SB 203580, and abolished by BAPTA/AM and nuclear factor κB (NF-κB) inhibitor, PDTC. PGE2, TNF-α, and IL-6 release by LPS alone were attenuated by Ro 31-8220, Go6976, PD 098059, SB 203580, and PDTC. Using l-NAME, soluble TNF-α receptor, IL-6 antibody, NS-398, and indomethacin, we performed experiments to understand the cross-regulation by the four mediators. The results revealed that TNF-α up-regulated NO, PGE2, and IL-6 synthesis; PGE2 up-regulated NO, but down-regulated TNF-α synthesis; and PGE2 and IL-6 mutually up-regulated reciprocally. Taken together, murine peritoneal macrophages required a sustained [Ca2+]i increase, which proceeds after TG, but not UTP, stimulation, to enhance LPS-mediated release of inflammatory mediators, particularly for NO induction. Activation of PKC-, ERK-, and p38 MAPK-dependent signaling also are essential for LPS action. The positive regulatory interactions among these mediators might amplify the inflammatory response caused by endotoxin.
Dietary fatty acids influence the production of Th1- but not Th2-type cytokines
Authors: Wallace Fiona A , Miles Elizabeth A , Evans Carl , Stock Theresa E , Yaqoob Parveen , Calder Philip C 
Published: September 2022

AbstractC57Bl6 mice were fed for 6 weeks on a low-fat diet or on high-fat diets containing coconut oil (rich in saturated fatty acids), safflower oil [rich in n-6 polyunsaturated fatty acids (PUFAs)], or fish oil (rich in n-3 PUFAs) as the main fat sources. The fatty acid composition of the spleen lymphocytes was influenced by that of the diet fed. Thymidine incorporation into concanavalin A-stimulated spleen lymphocytes and interleukin (IL)-2 production were highest after feeding the coconut oil diet. Interferon (IFN)-γ production was decreased by safflower oil or fish oil feeding. IL-4 production was not significantly affected by diet, although production was lowest by lymphocytes from fish oil-fed mice. The ratio of production of Th1- to Th2-type cytokines (determined as the IFN-γ/IL-4 ratio) was lower for lymphocytes from mice fed the safflower oil or fish oil diets. After 4 h of culture, IL-2 mRNA levels were higher in cells from mice fed coconut oil, and IFN-γ mRNA levels were higher in cells from mice fed coconut oil or safflower oil. After 8 h of culture, IL-2, IFN-γ, and IL-4 mRNA levels were lowest in cells from mice fed fish oil. The ratio of the relative levels of IFN-γ mRNA to IL-4 mRNA was highest in cells from mice fed coconut oil and was lowest in cells of mice fed fish oil. The influence of individual fatty acids on IL-2 production by murine spleen lymphocytes was examined in vitro. Although all fatty acids decreased IL-2 production in a concentration-dependent manner, saturated fatty acids were the least potent and n-3 PUFAs the most potent inhibitors, withn-6 PUFAs falling in between in terms of potency. It is concluded that saturated fatty acids have minimal effects on cytokine production. In contrast, PUFAs act to inhibit production of Th1-type cytokines with little effect on Th2-type cytokines; n-3 PUFAs are particularly potent. The effects of fatty acids on cytokine production appear to be exerted at the level of gene expression.
Chemokines stimulate human T lymphocyte transendothelial migration to utilize VLA-4 in addition to LFA-1
Authors: Ding Ziqiang , Xiong Ke , Issekutz Thomas B 
Published: September 2022

AbstractLymphocyte infiltration in inflammation is induced by the dual actions of chemokines and cell adhesion molecules. The role of LFA-1 and VLA-4 in chemokine-induced T cell transendothelial migration (TEM) across cytokine-activated endothelium has not been examined. LFA-1, but not VLA-4, mediated blood T cell TEM to RANTES, macrophage inflammatory protein-1α (MIP-1α), and stromal cell-derived factor-1 (SDF-1), and across tumor necrosis factor α (TNF-α) or interferon-γ (IFN-γ) -stimulated endothelial cells (EC). Chemokine stimulation in combination with TNF-α activation of EC induced TEM, which was partially mediated by VLA-4. SDF-1 increased a β1-integrin activation epitope on T cells and enhanced VLA-4-mediated adhesion. Thus, LFA-1 mediates TEM under most conditions, but VLA-4 can also mediate TEM, although, in contrast to LFA-1, this requires exogenous chemokines and EC activation. In addition, an LFA-1- and VLA-4-independent pathway of lymphocyte TEM can also be induced by SDF-1.
The effects of extracellular pH on immune function
Authors: Lardner Anne 
Published: September 2022

AbstractThe effect of alterations in extracellular pH on cellular and humoral immune function is reviewed. Because acidic pH predominates at inflammatory loci and other sites of immune activity, most studies to date focus on the effect of acidic rather than alkaline pH. Investigations on polymorphonuclear leukocytes demonstrate mainly inhibition of chemotaxis, respiratory activity, and bactericidal capacity at reduced pH. Evidence of impaired lymphocyte cytotoxicity and proliferation at acidic pH is also beginning to emerge. Many of the clinical acidoses are accompanied similarly by immunodeficiency. Studies on macrophages and eosinophils are few and inconclusive. A small number of studies demonstrate acid-induced activation of complement proteins and the alternative complement pathway, plus increased antibody-binding to leukocytes at lowered pH. A differential effect of acidic pH on humoral and cellular immunity may, therefore, exist. Increasing recognition of the significance of extracellular pH in relation to immune function warrants further studies in this presently incomplete but rewarding field.
Sulfhydryl-2 domain-containing protein tyrosine phosphatase-1 is not a negative regulator of interleukin-4 signaling in murine mast cells
Authors: White Erik D , Andrews Ryan P , Hershey Gurjit K Khurana 
Published: September 2022

AbstractSulfhydryl-2 domain-containing tyrosine phosphatase-1 (SHP-1) has an important role in the negative regulation of many receptors including the interleukin (IL)-4 receptor. Motheaten mice (me/me) have a homozygous mutation in SHP-1 and do not possess functional SHP-1. Pre-B-cell lines derived from me/me mice have been reported to display prolonged IL-4-dependent activation of signal transducer and activator of transcription-6 (Stat6). We evaluated IL-4-dependent Stat6 activation and Fcɛ receptor 1 (FcɛRI) modulation in bone marrow-derived mast cells (BMMCs) from me/me and wild-type mice. IL-4 down-regulated FcɛRI expression in wild-type BMMCs but had no effect on FcɛRI expression in me/me BMMCs. Furthermore, me/me mast cells did not exhibit enhanced or prolonged IL-4-induced Stat6 activation compared with wild-type cells, indicating that mast cells possess alternative tyrosine phosphatases that are responsible for down-regulating Stat6 or can substitute for SHP-1. Thus, SHP-1 is not a negative regulator of IL-4 signaling in BMMCs. These results demonstrate the complexity and cellular specificity of these signaling pathways and indicate a previously unrecognized role for SHP-1 in murine mast cells.