Interleukin-8 and RANTES inhibit basophil histamine release induced with monocyte chemotactic and activating factor/monocyte chemoattractant peptide-1 and histamine releasing factor.

The objective of this study was to investigate the effect of interleukin-8 (IL-8) and RANTES on basophil histamine release induced with monocyte chemoattractant peptide-1 (MCP-1) and crude histamine releasing factor (HRF). IL-8 induced low levels of histamine release (8.5 +/- 0.5%) from basophils obtained from only six of 20 donors at high concentrations (10(-6) M). RANTES induced histamine release (16 +/- 2%) from basophils of four of 15 donors at 10(-7) M concentration. However, both IL-8 and RANTES inhibited MCP-1 and HRF-induced histamine release from basophils dose-dependently at concentrations of 10(-9) to 10(-7) M. Basophils from all donors showed a significant inhibitory response (greater than 15%). The maximal inhibition of MCP-1 and HRF by IL-8 was 28 +/- 4% and 48 +/- 8%, respectively. The maximal inhibition of MCP-1 and HRF by RANTES was 26 +/- 4% and 43 +/- 6%, respectively. Peripheral blood mononuclear cell-derived HRF was purified into three distinct peaks by reverse-phase high performance liquid chromatography. Peak I contained MCP-1 as judged by binding to an immunoaffinity column that was prepared with anti-MCP-1 antibody. IL-8 inhibited histamine release induced with all three peaks of HRF. The inhibition of histamine release by IL-8 was significantly higher in normal subjects than in allergic patients (59 +/- 9% versus 31 +/- 7%, P less than 0.05). Both IL-8 and RANTES inhibited cytokine-induced histamine release only and did not affect histamine release by anti-IgE, FMLP, and C5a.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prolonged induction of IL-8 gene expression in a human fibroblast cell line infected with reovirus serotype 1 strain Lang

Viruses which infect mucosal surfaces commonly infect these particular anatomical sites based on both the virion structure and the interaction of the virus with a particular microenvironment. We infected a human lung epithelial cell line, a human gut epithelial cell line, and a human lung fibroblast cell line with reovirus 1/L to explore how this natural isolate of both the lung and the gut may interact with mucosal surfaces. While reovirus infection of the gut and lung epithelial cell lines was lytic, a chronic infection was established in the human lung fibroblast cell line. All three cell lines also produced interleukin-8 (IL-8) after infection with reovirus 1/L, and IL-8 production was not dependent upon viral replication. A prolonged production of IL-8 was observed in the chronically infected lung fibroblast cell line, suggesting that this mucosal population may be involved in the generation of inflammatory responses after the resolution of the initial lytic infection of the epithelium. These studies provide an in vitro model system for analyzing the interaction of reovirus 1/L with resident mucosal cell populations.     

Neutrophil chemotactic factor (IL-8) gene expression by cytokine-treated retinal pigment epithelial cells.

The neural-derived retinal pigment epithelium (RPE) underlies the sensory retina and is central to both retinal homeostasis and many common retinal diseases. Retinal pigment epithelium cells are actively phagocytic and share several features with macrophages that have recently been shown to produce a neutrophil chemotactic factor (NCF), also known as interleukin-8, after cytokine stimulation. Because RPE cell responses to cytokines are largely unknown, human RPE cell NCF production was monitored after interleukin-1-beta (IL-1 beta), tumor necrosis factor-alpha, or lipopolysaccharide stimulation. RPE NCF mRNA expression and RPE production of biologically active NCF was time and concentration dependent. Maximal NCF mRNA expression occurred at 20 ng/ml for IL-1 beta. Messenger RNA expression in RPE cells and biologically active NCF in RPE cell supernatants were found 1 hour after stimulation and were maintained for 24 hours. These findings demonstrate that cytokine-stimulated RPE cells may evoke or augment neutrophil-mediated inflammation by synthesizing NCF, a cytokine that may be important in ocular disease mechanisms.     

Apolipoprotein(a) is a human vascular endothelial cell agonist: studies on the induction in endothelial cells of monocyte chemotactic factor activity

Elevated levels of lipoprotein(a), Lp(a), are associated with premature atherosclerosis; however, the mechanisms of its atherogenicity are not known. Recruitment of monocytes to the blood vessel wall is an early event in atherogenesis. Since Lp(a) is associated with macrophages in the plaque, we have examined the effect of Lp(a) on inducing monocyte chemotactic activity (MCA) in vascular endothelial cells. We report that Lp(a) and apo(a) induced human umbilical vein (HUVEC) and coronary artery endothelial cells to secrete monocyte chemotactic activity as early as 30 min of incubation. In the absence of cells, Lp(a) had no direct monocyte chemotactic activity. Actinomycin D and cycloheximide inhibited the HUVEC response, indicating that protein and RNA synthesis were required. Endotoxin was shown not to be responsible for the induction of monocyte chemotactic activity. Granulocyte monocyte-colony stimulating factor antigen was not detected in the Lp(a)-conditioned medium, nor was monocyte chemoattractant protein-1 mRNA induced by Lp(a). These results suggest that Lp(a) may be involved in the recruitment of monocytes to the vessel wall, thus providing a novel mechanism for the participation of Lp(a) in the atherogenic process.     

Effects of TNF-alpha on IL-8 mRNA expression in endothelial cells]

As a kind of chemokine, IL-8 plays an important role in inflammatory reaction. Its expression in endothelial cells is regulated by a variety of cytokines. In this study, after incubating cultured human umbilical vein endothelial cells(HUVECs) with TNF-alpha for different time, we employed RT-PCR to assay IL-8 mRNA expression and immunocytochemical staining to detect NF-kappa B activation in HUVECs. The results revealed: (1) IL-8 mRNA expressed little in untreated HUVECs; after HUVECs was pre-incubated with TNF-alpha for 1 hour, IL-8 mRNA expression increased greatly, and it increased further after pre-incubated for 3 hours; however, when HUVECs was pre-incubated with TNF-alpha for 6 hours, IL-8 mRNA expression decreased, and it almost decreased to basal level when pre-incubated for 9 hours; (2) the immunoreactivity of NF-kappa B p65 in the nuclei of untreated HUVECs was negative; it became positive in the nuclei of HUVECs pre-incubated with TNF-alpha for 1 hour and 3 hours; it became weak positive in the nuclei of HUVECs pre-incubated with TNF-alpha for 6 hours, and after 9 hours, pre-incubation, the immunoreactivity of NF-kappa B p65 in the nuclei of HUVECs was negative. These results implied that TNF-alpha was capable of inducing IL-8 gene expression and activation NF-kappa B. and Their time courses were similar, thus suggesting that the induction of IL-8 gene expression by TNF-alpha is probably due to the activation of NF-kappa B.     

Hypoxia induces expression of the chemokines monocyte chemoattractant protein-1 (MCP-1) and IL-8 in human dermal fibroblasts

Hypoxia is an important factor in the pathophysiology of vascular and inflammatory diseases. Leucocyte infiltration, as a consequence of adhesion molecule up-regulation and chemokine release, is a prominent feature of these diseases. The objective of our study was to investigate the potential role of resident fibroblasts in hypoxia-induced chemotactic responses. We show that MCP-1 and IL-8 mRNA are specifically induced by hypoxia in dermal fibroblasts. This response is paralleled by increased NF-kappaB p65/p50 binding activity, and it is inhibited by pretreatment with N-acetyl-L-cysteine. MCP-1 secreted by fibroblasts is chemotactic for monocytic cells and this activity is significantly increased by hypoxia. Chemotactic index correlates with MCP-1 protein levels and is significantly decreased by neutralizing anti-MCP-1 MoAb. These findings demonstrate the ability of resident fibroblasts to mediate chemotaxis of leucocytes through the release of chemokines in response to hypoxia. Our data point to MCP-1 as an important component in this response, and therefore it may be a potential target in inflammatory responses associated with hypoxia.     

Apolipoprotein(a) inhibits lipopolysaccharide-induced IL-6 secretion in human astrocytoma cell line by interfering with lipopolysaccharide signaling

Objective  

To examine the role of lipoprotein(a) [Lp(a)] on the inflammatory response of cells in the nervous system by investigating its effect on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) secretion.     

Prevention of myocardial reperfusion injury in rats by an antibody against monocyte chemotactic and activating factor/monocyte chemoattractant protein-1

MCAF (monocyte chemotactic and activating factor)/MCP-1 (monocyte chemoattractant protein-1) is an important mediator of monocyte recruitment to inflammatory sites. However, its pathophysiologic role in myocardial reperfusion injury remains unknown. Male Wistar rats were anesthetized, and the left anterior descending coronary artery was ligated for an hour, after which the ligature was released. Northern blotting analysis revealed that MCAF/MCP-1 mRNA expression increased 16-fold in the reperfused region at 12 hours after reperfusion. MCAF/MCP-1 concentration in plasma and the heart was already elevated after hour of ischemia in this model. Goat polyclonal antibodies were prepared by repeated immunization of animals with purified, recombinant rat MCAF/MCP-1, and the neutralizing activities of this antibody were confirmed by monocyte chemotaxis assay and administration to rats with crescentic glomerulonephritis. Intravenous injection of anti-MCAF/MCP-1 antibody significantly reduced the infarct size at 24 hours after reperfusion compared with the injection of control IgG (33.9 +/- 5.1% vs 49.4 +/- 2.7% of ischemic area, mean +/- SEM). Administration of this antibody markedly decreased the intercellular adhesion molecule-1 mRNA expression and infiltration of macrophages, which suggested the pathophysiologic role of MCAF/MCP-1. Neutralization of MCAF/MCP-1 is beneficial by preventing reperfusion injury in a rat model of myocardial ischemia and reperfusion.     

Effect of IL-1beta,TNF-alpha and IL-4 on complement regulatory protein mRNA expression in human articular chondrocytes

Most of the cells possess complement regulatory proteins (CRPs) that protect them against complement-mediated damage. In our previous work we revealed that human articular chondrocytes express CPRs. Moreover, increase of CRPs expression after treatment of chondrocytes with proinflammatory cytokines IL-1beta and TNF-alpha has been demonstrated by ELISA technique. Chondroprotective cytokine IL-4 stimulated expression of CD46 only. In this work RT-PCR technique was used to evaluate the expression of mRNA of cell surface CPRs in cultured isolated articular human chondrocytes after treatment with IL-1beta, TNF-alpha and IL-4. Chondrocytes stimulated with IL-1beta and TNF-alpha showed augmented levels of CD46, CD55 and CD59 mRNA. Treatment with IL-4, however, increased only the level of CD46 mRNA. These results confirm and extend our previous observations. CD35 mRNA was not found. Expression of complement regulatory proteins on chondrocytes and its upregulation by cytokines stimulating matrix degradation could be important for the protection of these cells against complement-mediated lysis, which might be caused by immunocomplexes deposited in articular cartilage in inflammatory joint diseases.     

Expression of monocyte chemoattractant protein 1 (MCP-1) in adult periodontal disease: increased monocyte chemotactic activity in crevicular fluids and induction of MCP-1 expression in gingival tissues.

The present study shows that monocyte chemotactic activity in crevicular fluids increases with severity of the disease and that a monocyte chemoattractant, monocyte chemoattractant protein 1 (MCP-1), is expressed as the predominant cytokine of gingival tissues and their fibroblasts treated with Porphyromonas (Bacteroides) gingivalis lipopolysaccharide (P-LPS). High monocyte chemotactic activity in the crevicular fluids was neutralized significantly by antiserum specific for the JE/MCP-1 protein. Marked expression of the MCP-1 gene was observed in the gingival tissues of all adult periodontal patients tested, but not in those of healthy subjects. Monocyte chemotactic activity was observed in culture supernatants of human normal gingival tissues treated with P-LPS, and the chemotactic activity increased in a dose-related manner. Expression of MCP-1 in P-LPS-treated human gingival fibroblasts was further examined. P-LPS induced the MCP-1 gene expression in a dose- and treatment time-dependent manner. The MCP-1 gene product in the culture supernatant was detected as two forms with molecular masses of 11,000 and 15,000 Da by immunoprecipitation with the specific antiserum. The MCP-1 gene expression was induced in the fibroblasts treated with interleukin-1 beta and tumor necrosis factor alpha, but not with interleukin-6. These results suggest that gingival fibroblasts can participate in monocyte recruitment in gingival tissues of adult periodontal patients via the MCP-1 gene product and that MCP-1 plays an important role in the inflammatory reaction in the disease.     

Roles and relationship of macrophages and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 in the ischemic and reperfused rat heart

Reperfusion injury is a troublesome and unresolved problem in acute myocardial infarction and is believed to be associated with inflammatory reactions in which various types of cells and cytokines participate, in particular, macrophages and monocyte chemoattractant protein-1 (MCP-1). We designed this study to clarify the role and relationship of macrophages and MCP-1 in ischemic and reperfused heart. The number and distribution of macrophages and MCP-1 messenger RNA (mRNA) in the ischemic and reperfused rat heart were examined with in situ hybridization and immunohistochemistry. Myocardial samples were obtained at several times. In situ hybridization was performed with digoxigenin-labeled antisense RNA probe for rat MCP-1 mRNA, and immunohistochemistry was performed with antimacrophage antibody. Double staining with in situ hybridization and immunohistochemistry was also performed. The number of MCP-1 mRNA-positive cells increased after reperfusion and peaked at 3 hours after reperfusion. Early infiltration of ischemic tissues by macrophages was also observed at the time of the absence of an increase of MCP-1 mRNA-positive cells, and this infiltration was not significantly accelerated by reperfusion, but by ischemia itself. The numbers of both MCP-1 mRNA-positive cells and macrophages increased in the ischemic marginal region over time. From the result of double staining, and based on the cellular morphology and the distribution, the majority of MCP-1 mRNA-positive cells appeared to be activated macrophages. This suggests that macrophages may not be attracted to cardiac tissue only by MCP-1 and that MCP-1 may have some roles other than attracting macrophages into ischemic heart. It also suggests that macrophages and MCP-1 may play an important role in reperfusion injury and that MCP-1 may be one of the key molecules of reperfusion injury. These observations may contribute to the development of a new therapeutic approach to the prevention of reperfusion injury.     

TNF-alpha and IL-6 induce differentiation in the human basophilic leukaemia cell line KU812.

The basophilic leukaemia cell line KU812 can be induced to differentiate into basophil-like cells in vitro when exposed to supernatant from the Mo T-cell line. KU812 cells express affinity receptors for IgE, produce histamine and tryptase and have the capacity for IgE-mediated histamine release. In this study we have examined the cytokines, produced by the Mo cell line, which are responsible for the observed differentiation-inducing effect in the KU812 cell line. It was shown that interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) induced differentiation in the KU812 cells and that these cytokines were responsible for the differentiation-inducing effect of the Mo supernatant. Other cytokines tested, IL-1 beta, IL-2, IL-4, IL-5, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and nerve growth factor (NGF) were without effect on the KU812 cells. KU812 was also shown to express receptors for both TNF-alpha and IL-6 after 3 days cultivation with conditioned media from the Mo T-cell line. Untreated cells showed no detectable levels of TNF-alpha or IL-6 receptors indicating induction of these receptors during differentiation. Spontaneous differentiation was shown to occur under serum-free conditions which may be the result of endogenous IL-6 production through an autocrine loop. The activity of TNF-alpha and IL-6 could be blocked by specific monoclonal antibodies (mAb) to the respective cytokine.