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A novel cytokine, interleukin-8 (IL-8), may play major roles in the inflammatory process by recruiting neutrophils and T cells into inflammatory sites. The production of this cytokine is not constitutive and is induced in a variety of cell types by stimulation with mitogens and cytokines. Among cytokines, only IL-1 and tumor necrosis factor (TNF) can induce IL-8 gene expression at the transcriptional level. Transfection of a human fibrosarcoma cell line with chloramphenicol acetyltransferase expression plasmids linked to a 5'-flanking deletion mutants of the IL-8 gene demonstrated that the nucleotides between -94 and -71 base pairs from the start of the first exon are essential and sufficient for the IL-8 induction by either IL-1, TNF, or phorbol 12-myristate 13-acetate. This sequence is composed of two cis-elements; one is the potential binding site for a nuclear factor-kappa B-like factor and the other for a cis-regulatory enhancer binding protein-like factor. Mutations in either elements abolished IL-1, TNF, and phorbol 12-myristate 13-acetate responsiveness. This report provides the first evidence that cooperation between two distinct cis-elements may be required for induction of gene expression by either IL-1 or TNF.

Monocyte-derived neutrophil chemotactic factor (MDNCF/IL-8, suggested gene symbol IL8) is a cytokine that chemoattracts and activates neutrophils. Using a panel of human-rodent cell hybrids that preferentially segregate human chromosomes and in situ hybridization, the MDNCF/IL-8 gene was placed on the human gene map at position 4q12-q21. This is the same location where at least three other members (platelet factor 4, melanoma growth stimulatory activity, and interferon-gamma induced factor) of the platelet factor 4 gene super-family reside. In addition, a restriction fragment length polymorphism was identified using MDNCF as a probe in screening genomic DNA digested with HindIII from unrelated individuals.

Malignant fibrous histiocytoma is the most frequent soft tissue sarcoma. However, the pathogenesis still remains unclear, because there are very few human malignant fibrous histiocytoma cell lines available for precise cellular study. In this study, a human malignant fibrous histiocytoma cell line (MMF-1) was established from the pulmonary metastatic lesion of a 55-year-old man with malignant fibrous histiocytoma. Human cell line MMF-1 and its heterotransplanted tumor had almost the same characteristics as the original tumor morphologically and immunohistochemically. This cell line is expected to be a useful for studying the pathogenesis of malignant fibrous histiocytoma. The cloned cell lines (MMF-2 and MMF-3) also consisted of spindle-shaped, polygonal, and multinucleated giant cells, meaning that the fibroblast-like cells, histiocyte-like cells, and multinucleated giant cells seen in malignant fibrous histiocytoma were derived from a single tumor cell. Human cell line MMF-1 produced inflammatory cytokines, such as tumor necrosis factor-alpha, macrophage colony-stimulating factor, interleukin-8, and monocyte chemotactic and activating factor, that might be involved in the morphogenesis of malignant fibrous histiocytoma. Furthermore, the results of the analysis of human cell line MMF-1 suggested that malignant fibrous histiocytoma originated from a poorly differentiated fibroblast.

The role of interleukin 1 (IL1) in causing IL2 and interferon-gamma (IFN-gamma) production and their associated gene activation has been studied in a human leukemic HSB.2 subclone. One of the subclones, HSB.2-C5B2 clone #28, which produced only low levels of IL2 and IFN-gamma when stimulated with phytohemagglutinin (PHA) or with a combination of phorbol-myristate-acetate (PMA) and Ca2+ ionophore, ionomycin, showed marked IL2 and IFN-gamma production in the presence of IL1. The augmentation by IL1 was observed in both dot and Northern blot analysis, indicating that IL1 regulates lymphokine genes at the pretranslational level. The kinetics of IL2 and IFN-gamma production were essentially similar for both lymphokines except that there was a faster accumulation of IFN-gamma mRNA than IL2 mRNA. In contrast to the IL2 and IFN-gamma gene activation, IL2 receptor (Tac/p55 antigen) expression was induced directly by IL1 itself as with PMA in this subclone. In these studies, IL1 action was not replaced by the drugs raising intracellular cyclic AMP (cAMP). Taken collectively, these experiments support the notion that IL1 does not trigger IL2 gene activation per se, but amplifies the preactivated lymphokine genes initiated by PMA and ionomycin, whereas IL1 can activate the IL2 receptor gene without any other known signal requirements.

We have observed that CT6 cell line, a murine interleukin 2 (IL 2)-dependent T cell line, was highly responsive to phorbol myristate acetate (PMA) and to a lesser extent but significantly responsive to lipopolysaccharide (LPS) in the short-term proliferation assay. In contrast, two other murine IL 2-dependent cell lines, CTLL-2 and NK clone 7, were totally unresponsive to these stimulants. Even when CT6 was recloned by a limiting dilution, no unresponsive clone to PMA was obtained, whereas several clones unresponsive to LPS were obtained. PMA, unlike to IL 2, could not support a long-term culture of CT6. There are no differences between CT6 and CTLL-2 except that the former possessed asialo GM1 while the latter lacked it. Though it is unknown whether this difference is involved in the mechanism of the response of CT6 to PMA or LPS, these data give caution to us against the use of CT6 for the determination of IL 2 activity contaminated with PMA and LPS.

Two monoclonal antibodies were raised against human interleukin-2 (IL-2) produced by E. coli harboring recombinant complemental DNA. Both antibodies did not neutralize its activity, nor did they inhibit the binding of IL-2 to the receptor on target cells. Taking advantage of the ability of monoclonal antibodies to detect IL-2 that had bound to the receptor, a radioimmunoassay was developed that sandwiched IL-2 between the radiolabeled monoclonal antibody and the receptor on a hematopoietic cell line infected with human T cell leukemia virus Type I. The assay had the advantage of detecting only IL-2 with the ability to bind to the receptor, and displayed a linear dose-response relationship over concentrations ranging from 5 to 100 ng/ml.

The effects of recombinant interleukin 2 (re-IL2) and interferonγ (re-IFNγ) on the natural killer (NK) cell activity were studied, special cares being paid to elucidate the interrelationship between these lymphokines. Peripheral blood lymphocytes from normal volunteers and gastrointestinal cancer patients were obtained by Ficoll-Urografin sedimentation. Augmentation of NK cell activity was induced after incubating the cells with various doses of re-IL2 or re-IFNγ for 18 hours. NK cell activity was measured by the 4.5hr 51Cr-release assay using K-562 cells as a target. The NK cell activity from both normal donors and cancer patients was greatly enhanced by re-IL2. This augmentation of NK cell activity by re-IL2 was dose dependent and even as small dose as 10u/ml of re-IL2 was able to augment NK cell activity significantly. On the other hand, augmentation of NK cell activity by re-IFNγ (range-8.8 to 19.6% at 1, 000u/ml) was much less, although significant, than that induced by re-IL2 (19.1 to 65.7% at 100u/ml). These results indicate that re-IL2 much more effective than re-IFNγ in the augmentation of NK cell activity in vitro. No significant differences were observed in the augmentation ratios of NK cell activity by either re-IL2 or re-IFNγ among the different cancer stages. Although re-IL2 could augment NK cell activity regardless the donors conditions, healthy or cancerous, it did not necessarily always induce IFNγ activity. Hence, we speculate that re-IL2 might work directly on NK cells without mediating IFNγ induction.

Role of protein kinase C (PKC) in interleukin (IL) 2-induced proliferation was investigated by utilizing two murine IL 2-dependent cell lines, CT6 and CTLL-2 cell lines. CT6 cells showed a marked proliferative response to phorbol 12-myristate 13-acetate (PMA), while CTLL-2 did not. PMA induced PKC translocation from cytosol to membrane only in a PMA-responsive cell line. IL 2 failed to stimulate PKC translocation in both cell lines. H-7, a potent and specific PKC inhibitor, however, inhibited the proliferation of both cell lines induced by IL 2. Taken collectively, IL 2 may induce PKC activation without its translocation.

Detection of urinary interleukin-8 in glomerular diseases. To clarify the mechanism of neutrophil infiltration in glomerulonephritis, both urinary and plasma levels of a potent neutrophil chemotactic cytokine, interleukin-8 (IL-8), were measured in 40 healthy volunteers and 96 patients with various renal diseases. The plasma IL-8 levels were less than 16 pg/ml. The urinary IL-8 levels were elevated in several renal diseases including IgA nephropathy (17 of 43), acute glomerulonephritis (4 of 6), lupus nephritis (11 of 15), purpura nephritis (2 of 4), membranoproliferative glomerulonephritis (1 of 1), and cryoglobulinemia (2 of 2). IL-8 was detected immunohistochemically in diseased glomeruli, suggesting its local production. Elevated urinary IL-8 levels during the acute phase or exacerbations were found to be decreased during spontaneous or steroid pulse therapy-induced convalescence in all patients examined. The urinary IL-8 levels were higher in patients with glomerular leukocyte infiltration than in those without infiltration. Collectively, local production of IL-8 in diseased glomeruli might be involved in the pathogenesis of the glomerular diseases and measurement of IL-8 in the urine might be useful for monitoring the glomerular diseases.

We have previously established a non-competitive solid-phase enzyme-linked immunosorbent assay (ELISA) specific for interleukin-1 alpha (IL-1 alpha) using a combination of polyclonal antibody as the immobilized antibody, biotinylated monoclonal antibody as the second antibody and avidin-peroxidase. The level of detection of that ELISA was 200-500 pg/ml. In order to improve its sensitivity, we have used streptavidin-beta-D-galactosidase and the fluorogenic substance 4-methylumbelliferyl-D-galactopyranoside as enzyme substrate. With this system IL-1 alpha could be detected at concentrations as low as 10-50 pg/ml, which was about 10-20 times more sensitive than conventional mouse thymocyte co-stimulator assays. Furthermore, the assay system was specific for IL-1 alpha in that neither IL-1 beta nor interleukin-2 (IL-2) interfered.

A partially purified human urinary colony-stimulating factor (pp-CSF), with a specific activity of 1.0 X 10(6) U/mg protein, was purified by using a stepwise DEAE-cellulose anion exchange chromatography and a molecular sieve high performance liquid chromatography (TSK gel G3000SW) sequentially. Production of three kinds of monokines by human peripheral blood monocytes was tested in vitro, which contained granulocytic colony-stimulating activity (G-CSA), interleukin 1 (IL-1) and interferon alpha (IFN-alpha). Human peripheral blood mononuclear cells were separated by Ficoll-Hypaque density gradient centrifugation, and monocytes were obtained by adherence to dishes. Although pp-CSF stimulated monocytes to produce G-CSA in vitro, it failed to stimulate the IL-1 or IFN-alpha production. The discrepancy between production or release of these three kinds of monokines by human monocytes stimulated with pp-CSF suggests that pp-CSF preferentially stimulates human monocytes to produce G-CSA. To test the effects of pp-CSF on human monocytes in vivo, we performed i.v. infusions of pp-CSF to four volunteers, and we then took peripheral blood monocytes. Compared to before the infusion of pp-CSF, G-CSA production by monocytes was enhanced, while production of IL-1 and IFN-alpha was not enhanced after the infusion of pp-CSF. These results suggest that pp-CSF stimulates monocytes to produce G-CSA but not to produce IL-1 nor IFN-alpha.

A family consisting of at least ten distinct novel 8-10 kd cytokines has been identified over the past 12 years. These cytokines exhibit from 20 to 45% homology in amino acid sequence, are probably all basic heparin-binding polypeptides, and have proinflammatory and reparative activities. The cDNA for these cytokines are characterized by conserved single open reading frames, typical signal sequences in the 5' region, and AT rich sequences in the 3' untranslated regions. Those human cytokines known as interleukin 8, platelet factor 4, beta thromboglobulin, IP-10 and melanoma growth stimulating factor or GRO can be assigned to a subfamily based on their location on chromosome 4 and unique structural features, whereas the second subset consisting of LD78, ACT-2, I-309, RANTES, and macrophage chemotactic and activating factor (MCAF) are all closely linked on human chromosome 17. In this review we have summarized and discussed the available information concerning the regulation and structure of the genes, the structure and biochemical properties of the polypeptide products, their receptors, signal transduction, cell sources, and in vitro as well as in vivo activities of these cytokines.

Purpose To address the roles of the stromal derived factor-1 (SDF-1) α in the course of experimental corneal neovascularization (CNV). Methods CNV was induced by alkali injury and compared in SDF-1α- or vehicle-treated mice two weeks after injury. Angiogenic factor expression in the early phase after injury was quantified by reverse transcription polymerase chain reaction (RT-PCR). Progenitor cell, macrophage, and monocyte intracorneal accumulation in the early phase after injury was evaluated by flow cytometric analysis. Results The mRNA expression of SDF-1α was augmented, together with infiltration of c-kit-positive progenitor cells in the corneas after the alkali injury. Compared with vehicle-treated mice, SDF-1α-treated mice exhibited enhanced CNV two weeks after injury, as evidenced by enlarged cluster of differentiation 31 (CD31)-positive areas. Concomitantly, the intracorneal infiltration of c-kit-positive progenitor cells but not F4/80+ macrophages or Ly-6G+ monocytes was significantly enhanced in SDF-1α-treated mice compared to vehicle-treated mice. SDF-1α enhanced vascular endothelial growth factor (VEGF) expression by murine peritoneal macrophages. Enhancement in intraocular VEGF expression was greater in SDF-1α-treated mice than in control mice after injury. Moreover, local administration of C-X-C chemokine receptor type 4 (CXCR4) antagonist after alkali injury reduced alkali-induced CNV. Conclusions SDF-1α-treated mice exhibited enhanced alkali-induced CNV through enhanced intracorneal progenitor cell infiltration and increased VEGF expression by macrophages.

Since the discovery 13 years ago of interleukin (IL)-8 as a potent neutrophil chemotactic factor, accumulating evidence has established it as a crucial mediator in neutrophil-dependent acute inflammation. Numerous observations have demonstrated that various types of cells can produce a large amount of IL-8, either in response to various stimuli or constitutively, after malignant transformation. Recent studies of IL-8-mediated signaling have revealed that IL-8 activates a wide range of signaling molecules in a coordinate manner. IL-8 has been proven to have diverse actions on various types of leukocytic and nonleukocytic cells besides neutrophils. The author reviews recent progress in IL-8 signal transduction and biological actions on nonneutrophilic leukocytes, including T lymphocytes, monocytes, and hematopoietic progenitor cells. Potential involvement of IL-8 in viral infections and tumor progression is also discussed.

The pathophysiologic effects of FR167653 were investigated in a model of crescentic glomerulonephritis induced by a small dose of nephrotoxic serum in Wistar-Kyoto rats. The rats developed crescentic glomerulonephritis by 6 d after the administration of serum. The subcutaneous administration of FR167653 (32 mg/kg) markedly decreased the severity of the renal damage. In a group of rats treated with FR167653 daily from day 0 to day 6, glomerular damage, including crescent formation and proteinuria, was virtually absent. FR167653 markedly decreased urinary levels of monocyte chemoattractant protein-1 (MCP-1). In addition, FR167653 reduced production of MCP-1 protein and transcripts in the diseased kidneys. In a group of rats for which treatment was initiated on day 3, shortly after the appearance of glomerular abnormalities, the progression of renal disease was appreciably retarded, with partial inhibition of MCP-1. In contrast, when rats were treated only on the first day, no beneficial effects were observed and severe proliferative and necrotizing glomerulonephritis, with crescent formation, was induced by day 6, with the upregulation of MCP-1. These results suggest that FR167653 may be effective against crescentic glomerulonephritis, possibly via the inhibition of MCP-1. In addition, there was marked reduction in renal injury even when FR167653 treatment was initiated after glomerular inflammation was established, suggesting that the therapeutic application of FR167653 may be clinically useful for human renal diseases.

We investigated the pathophysiological role of a potent macrophage (M(phi)) chemotactic cytokine (chemokine), monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 (MCAF/MCP-1), in an animal model of crescentic glomerulonephritis. Administration of a small dose of nephrotoxic sera induced severe proliferative and necrotizing glomerulonephritis, with crescentic formation in the early phase and glomerulosclerosis in the later phase, in Wistar-Kyoto rats. MCAF/MCP-1 protein was detected immunohistochemically in glomeruli, vascular endothelial cells, and tubular epithelial cells in the early phase of injured kidney tissues but not in normal ones. Anti-MCAF/MCP-1 antibodies decreased the number of M(phi) in glomeruli, and prevented crescentic formation and the fusion of epithelial cell foot process in nephritic rats, thereby decreasing the excreted amounts of protein to normal levels on days 3 and 6. Furthermore, anti-MCAF/MCP-1 antibodies remarkably reduced glomerulosclerosis and improved renal dysfunction as well as proteinuria in the later phase (56 days). These results indicate that MCAF/MCP-1 essentially participates in the impairment of renal functions associated with crescentic glomerulonephritis by recruiting and activating M(phi).

Tumor recurrence rates remain high after curative treatments for hepatocellular carcinoma (HCC). Immunomodulatory agents, including chemokines, are believed to enhance the antitumor effects of tumor cell apoptosis induced by suicide gene therapy. We therefore evaluated the immunomodulatory effects of a bicistronic recombinant adenovirus vector (rAd) expressing both HSV thymidine kinase and MCP-1 on HCC cells. Using an athymic nude mouse model (BALB/c-nu/nu), primary s.c. tumors (HuH7; human HCC cells) were completely eradicated by rAd followed by treatment with ganciclovir. The same animals were subsequently rechallenged with HCC cells, tumor development was monitored, and the recruitment or activation of NK cells was analyzed immunohistochemically or by measuring IFN-γ mRNA expression. Tumor growth was markedly suppressed as compared with that in mice treated with a rAd expressing the HSV thymidine kinase gene alone (p < 0.001). Suppression of tumor growth was associated with the elevation of serum IL-12 and IL-18. During suppression, NK cells were recruited exclusively, and Th1 cytokine gene expression was enhanced in tumor tissues. The antitumor activity, however, was abolished either when the NK cells were inactivated with anti-asialo GM1 Ab or when anti-IL-12 and anti-IL-18 Abs were administered. These results indicate that suicide gene therapy, together with delivery of MCP-1, eradicates HCC cells and exerts prolonged NK cell-mediated antitumor effects in a model of HCC, suggesting a plausible strategy to prevent tumor recurrence.

Interleukin-8 (IL-8) exhibits activities on bone marrow progenitor cells such as regulation of their growth and their mobilization into peripheral blood. In order to clarify the molecular mechanism of the effects of IL-8 on mouse bone marrow cells, we examined the cellular distribution of mouse IL-8 receptor homologue by an immunofluorescence analysis. Peripheral blood Gr-1+ mature granulocytes, and a substantial portion of NK1.1+ natural killer cells in peripheral blood and spleen were stained positively with anti-mouse IL-8 receptor homologue antibody, whereas CD4+, CD8+, or B220+ lymphocytes in peripheral blood and spleen, and thymocytes were not. Moreover, a small portion of ER-MP20+ monocytes in peripheral blood but neither peritoneal resident nor bone marrow macrophages were stained with anti-IL-8 receptor homologue antibody. In bone marrow, mature granulocytes and to a lesser degree, metamyelocytes and myelocytes expressed IL-8 receptor homologue. Moreover, lineage marker (Lin)-c-kit+ bone marrow progenitor cells started to express IL-8 receptor homologue only 5 days after in vitro culture with IL-3 and stem cell factor when metamyelocytes and myelocytes appeared. These results indicated that myeloid lineage cells express a substantial number of IL-8 receptor homologues only at the stage of myelocytes.

The purpose of the present study was to examine the expression of interleukin (IL)-8 and IL-8 receptors and to evaluate the effects of IL-8 on human pancreatic cancer. We examined the expression of IL-8 and its two receptors (CXCR1 and CXCR2) in 40 surgically resected human pancreatic cancer tissues and in three different human pancreatic cancer cell lines (PANC-1, MIAPaCa-2 and Capan-2). The immunohistochemical analysis using specific antibodies demonstrated that positive staining for IL-8, CXCR1 and CXCR2 in surgically resected human pancreatic cancer was 50, 55 and 65%, respectively. Moreover, 40% of these cases were positive for both IL-8 and IL-8 receptors. In contrast, immunoreactive signals for those proteins were extremely suppressed in normal pancreatic tissues. All of the pancreatic cancer cell lines expressed IL-8 and IL-8 receptors at the RNA and protein levels. Receptor binding experiments using 125I-labeled IL-8 showed that PANC-1 cells had specific binding sites for IL-8. The cell proliferation assay demonstrated that IL-8 did not affect the growth of the three cell lines. However, treatment with IL-8 enhanced the invasiveness into Matrigel and increased the activity of matrix metalloproteinase (MMP)-2 in supernatants of the PANC-1 cells. These results demonstrate that IL-8 and IL-8 receptors are over-expressed in pancreatic cancer, and suggest that IL-8 regulates MMP-2 activity and plays an important role in the invasiveness of human pancreatic cancer.

Coculture of T98G glioblastoma cells with the myeloid and monocytic cell lines, HL-60, and THP-1 produced minimal amounts of interleukin-8 (IL-8). Pretreatment of HL-60 or THP-1 cells with phorbol myristate acetate (PMA) enhanced their capacity to induce IL-8 production by T98G cells. In contrast, the murine macrophage cell lines J774 A.1 and RAW 264.7 induced high levels of IL-8 production by T98G cells without PMA activation. To determine the molecules responsible for the induction of IL-8 by T98G cells, we carried out coculture experiments with a membrane fraction prepared from RAW cells and indicated that membrane-associated and free forms of murine IL-1alpha acted on human T98G cells to produce IL-8. RAW cells were unique in that increasing the number of RAW cells relative to the number of T98G cells (RAW/T98G ratio4:1) significantly suppressed IL-8 production by T98G cells. Because RAW cells produce large amounts of nitric oxide (NO), we assumed that the suppression of IL-8 production was ascribable to the NO produced by the RAW cells. This was supported by the inverse relationship between increasing concentrations of NO and IL-8 production seen in this coculture system. The involvement of NO in the suppression of IL-8 production was confirmed by the finding that N-monomethyl-L-arginine (NMMA), which inhibits NO production, reversed this suppression, whereas S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a strong NO generator, suppressed IL-8 production. Our results indicate that high levels of NO suppress IL-8 production by T98G cells, and murine IL-1alpha plays a major role in the induction of IL-8 production by T98G cells. It is, therefore, possible that excessive production of NO during the interaction of glioma cells with macrophages may play a regulatory role in chemokine production, thus mitigating inflammatory responses.

Background & Aims: Helicobacter pylori adheres to gastric epithelial cells, activates nuclear factor κB (NF-κB), and stimulates interleukin (IL)-8 production, but the responsible molecular mechanisms remain largely unknown. Because several studies have shown that sphingolipids are involved in a number of signaling pathways, including NF-κB activation, we investigated the possible role of sphingolipids in the regulation of IL-8 expression in Kato III and AGS cells. Methods: IL-8 production in the conditioned media was quantified by enzyme immunoassay. Induction of messenger RNA (mRNA) was assessed by Northern blot analysis. Activation and binding activity of transcription factors were examined by luciferase assay and electrophoretic mobility shift assay, respectively. Intracellular levels of ceramide were quantified by diacylglycerol kinase assay. Results: A cell-permeable ceramide analogue (C 2 -ceramide) increased IL-8 expression with comparable mRNA induction. This effect was mimicked by sphingomyelinase, but not by phospholipase A 2 or phospholipase C. C 2 -ceramide induced IL-8 gene transcription mainly through activation of NF-κB because mutation of the NF-κB–binding site completely abrogated the induction of luciferase activity. Direct contact of live H. pylori with epithelial cells increased the intracellular concentration of ceramide. Conclusions: The results suggest a novel role of the sphingomyelin-ceramide pathway, at least in part through NF-κB, in IL-8 production induced by H. pylori infection in gastric epithelial cells. GASTROENTEROLOGY 1999;116:1330-1341

Interleukin-8 (IL-8), a proinflammatory chemokine, is induced by viruses and appears in circulation during viral infections. We found that IL-8 enhanced cytopathic effect induced by the positive strand RNA virus, encephalomyocarditis virus (EMCV), in the human WISH cell line. The enhancement was dependent on IL-8 dose and virus dose and was reversible by specific monoclonal antibodies to IL-8. The chemokine was also able to increase EMC viral RNA synthesis and infectious virus yield. This IL-8 enhancing action was not observed in the case of the negative strand RNA virus, vesicular stomatitis virus (VSV), in WISH cells. We examined the activity of constitutive 2′,5′-oligoadenylate synthetase (OAS), a pathway that was implicated in protection from EMCV but not VSV. The IL-8 action in EMCV-infected cells, unlike VSV-infected cells, was associated with decreased OAS activity in a manner that was independent of OAS gene expression. Understanding mechanisms of cytokine enhancement of viral activity may lead to novel ways to control viral infections.

We measured the levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in the bronchoalveolar lavage (BAL) fluids from 27 patients with active pulmonary sarcoidosis and examined the relationship between chemokine levels and some clinical manifestations. The levels of two chemokines were assessed by enzyme-linked immunosorbent assay. There were significant positive correlations between the absolute number of lymphocytes and MCP-1 levels. The level of MCP-1 was significantly higher in the group with age at onset of over 50 year than that in the group with age at onset under 30 year. There were no significant differences between the non-smokers and smokers, or among the groups of patients classed according to stages. We conclude that MCP-1 can play an important role in the pathogenesis and clinical course of pulmonary sarcoidosis, although further analysis is needed to delineate the exact role of IL-8.

SUMMARYThe role of interleukin (IL)-8 as mediator in the recruitment of leucocytes into the CSF was investigated during experimental pneumococcal meningitis. Rabbits were inoculated intracisternally with approximately 106 CFU Streptococcus pneumoniae, and treated (i) intravenously with 5 mg of a monoclonal antibody to IL-8 (n = 7) or 5 mg of an isotype control antibody (n = 6); (ii) intracisternally with anti-IL-8, 100 µg (n = 5), 10 µg (n = 4), 1 µg (n = 4), 0·1 µg (n = 2). Ten rabbits served as untreated control group. Intravenous treatment with anti-IL-8 attenuated the pleocytosis significantly compared to untreated rabbits (P < 0·04) or rabbits treated with an isotype control antibody (P < 0·02). In contrast, intracisternal treatment with anti-IL-8 failed to attenuate the pleocytosis (P > 0·05). These results show, that IL-8 plays an important role in the recruitment of leucocytes during experimental pneumococcal meningitis, and that the functional activity of IL-8 in this process appears to be on the bloodstream side of the microvascular endothelium of the brain.

金沢大学がん研究所がん病態制御, Purpose: To evaluate the roles of CCL3 and its specific chemokine receptors, CCR1 and CCR5, in alkali-induced corneal neovascularization (CNV). Methods: Chemical denudation of corneal and limbal epithelium was performed on wild-type (WT) BALB/c mice and CCL3-, CCR1-, and CCR5-deficienct (knockout [KO]) counterparts. Two weeks after injury CNV was quantified by immunostaining with anti-CD31. Angiogenic factor expression and leukocyte accumulation in the early phase after injury were quantified by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical analysis, respectively. Results: Alkali injury augmented the intraocular mRNA expression of CCL3 and its receptors, CCR1 and CCR5, together with a transient infiltration of F4/80 positive macrophages and Gr-1 positive neutrophils. Compared with WT mice, CCL3-KO and CCR5-KO mice but not CCR1-KO mice exhibited reduced CNV two weeks after injury both macroscopically and microscopically as evidenced by CD31 positive areas. Concomitantly, the infiltration of F4/80 positive macrophages but not Gr-1 positive neutrophils was significantly attenuated in CCL3-KO mice compared with WT mice. Intracorneal infiltration of CCR5 expressing cells was significantly impaired in CCL3-KO mice compared with WT mice. Alkali injury induced a massive increase in the intraocular mRNA expression of a potent angiogenic factor, vascular endothelial growth factor (VEGF), in WT mice whereas these increments were severely retarded in CCL3-KO mice. Moreover, CCL3 enhanced VEGF expression by murine peritoneal macrophages at both the mRNA and the protein level. Furthermore, topical CCL3 application restored CNV, which was macroscopically and microscopically reduced in CCL3-KO mice after two weeks to levels similar to those found in WT mice. Conclusions: In alkali-induced CNV, CCL3 induced macrophages to infiltrate and produce VEGF by binding to CCR5 but not to CCR1 and eventually promoted angiogenesis. © 2008 Molecular Vision.

Helicobacter pylori VacA induces multiple effects on susceptible cells, including vacuolation, mitochondrial damage, inhibition of cell growth, and enhanced cyclooxygenase-2 expression. To assess the ability of H. pylori to modulate the production of inflammatory mediators, we examined the mechanisms by which VacA enhanced IL-8 production by promonocytic U937 cells, which demonstrated the greatest VacA-induced IL-8 release of the cells tested. Inhibitors of p38 MAPK (SB203580), ERK1/2 (PD98059), IκBα ((E)-3-(4-methylphenylsulfonyl)-2-propenenitrile), Ca2+ entry (SKF96365), and intracellular Ca2+ channels (dantrolene) blocked VacA-induced IL-8 production. Furthermore, an intracellular Ca2+ chelator (BAPTA-AM), which inhibited VacA-activated p38 MAPK, caused a dose-dependent reduction in VacA-induced IL-8 secretion by U937 cells, implying a role for intracellular Ca2+ in mediating activation of MAPK and the canonical NF-κB pathway. VacA stimulated translocation of NF-κBp65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-κB pathway. In addition, small interfering RNA of activating transcription factor (ATF)-2 or CREB, which is a p38MAPK substrate and binds to the AP-1 site of the IL-8 promoter, inhibited VacA-induced IL-8 production. VacA activated an IL-8 promoter containing an NF-IL-6 site, but not a mutated AP-1 or NF-κB site, suggesting direct involvement of the ATF-2/CREB binding region or NF-κB-binding regions in VacA-induced IL-8 promoter activation. Thus, in U937 cells, VacA directly increases IL-8 production by activation of the p38 MAPK via intracellular Ca2+ release, leading to activation of the transcription factors, ATF-2, CREB, and NF-κB.

Accumulating evidence implicates interleukin-8 (IL-8) as an essential mediator in neutrophil-mediated acute inflammation. Neutrophils have also been shown to have a crucial role in the pathogenesis of acute gouty arthritis. Thus, we investigate the pathophysiological role of IL-8 in an experimental model of acute gout, monosodium urate (MSU) crystal-induced arthritis in rabbits. The injection of MSU crystals into knee joints caused a marked swelling of joints. Concomitantly, the infiltration of leukocytes, mostly neutrophils, was observed in synovial membrane and synovial fluids. The injection of MSU crystals also induced an elevation in synovial fluid IL-8 levels preceding neutrophil infiltration into synovial fluids, without an accompanying increase in plasma IL-8 levels. Immunoreactive IL-8 protein was detected in synovial lining cells at 12–24 h after the injection. IL-8 protein was also observed in infiltrated leukocytes in synovium as early as 3–24 h after the injection. Finally, the intraarticular injection of a neutralizing anti-IL-8 antibody significantly attenuated the crystal-induced joint swelling that occurred at 12 h, and neutrophil infiltration into arthritic joints at 12 and 24 h after the induction. These results provide evidence on the pathogenic roles of locally produced IL-8 in MSU crystal-induced gouty arthritis.

The growth and spread of tumour cells depends on adequate vasculature. We have previously reported that the expression of interleukin-8 (IL-8) directly correlates with the vascularity of human gastric carcinomas. To provide evidence for a causal role of IL-8 in angiogenesis and tumorigenicity of human gastric cancer, we used the lipofectin method to stably transfect the human TMK-1 gastric carcinoma cells (low endogenous IL-8) with an IL-8 expression vector or control vector. Transfection with IL-8 did not affect the proliferation of cultured cells, yet the culture supernatants of the transfected (but not control) cells stimulated proliferation of human umbilical vein endothelial cells. The IL-8-transfected and control cells were injected into the gastric wall of nude mice. IL-8-transfected cells produced rapidly growing, highly vascular neoplasms as compared to control cells. These results provide direct evidence for the role of IL-8 in the angiogenesis and tumorigenicity of human gastric carcinomas. © 1999 Cancer Research Campaign

A human monocyte chemoattractant protein-1 (hMCP-1) transgenic mouse (Tgm) line which constitutively produces a large amount of hMCP-1 (7-13 ng/ml in the serum) was established. Although expression of the transgene was detected in various tissues, an accumulation of macrophages (Mphi) was seen in only lymphoid organs which might be attributed to the high concentration of hMCP-1 in these organs. A reduced phagocytosis by peritoneal Mphi in vivo and a delayed clearance of granulomas in the liver following zymosan administration were observed in these Tgm. However, peritoneal exudate cells (PEC) from Tgm exhibited normal in vitro phagocytic activity and nitric oxide (NO) production upon stimulation with IFN-gamma as compared with those from non-Tgm. In addition, high activities of src-family protein tyrosine kinases (PTK), Fgr and Hck, were also noted in the peritoneal resident cells from Tgm, whereas the level of mitogen-activated protein kinase (MAPK) activity was almost the same as that of non-Tgm. It was suggested that the low functional activities of Tgm Mphi seen in vivo were attributed to down-regulation of the unique transducing system of hMCP-1 signals under the influence of a high concentration of the hMCP-1. It seemed that the depressed functions were recovered when the peritoneal cells were released ex vivo from such a high hMCP-1 environment.

Cecal ligation and puncture (CLP) caused septic peritonitis in wild-type (WT) mice, with ∼33% mortality within 7 days after the procedure. Concomitantly, the protein level of intraperitoneal CX3CL1/fractalkine was increased, with infiltration by CX3CR1-expressing macrophages into the peritoneum. CLP induced 75% mortality in CX3CR1-deficient (CX3CR1−/−) mice, which, however, exhibited a similar degree of intraperitoneal leukocyte infiltration as WT mice. Despite this, CX3CR1−/− mice exhibited impairment in intraperitoneal bacterial clearance, together with a reduction in the expression of intraperitoneal inducible NO synthase (iNOS) and bactericidal proinflammatory cytokines, including IL-1β, TNF-α, IFN-γ, and IL-12, compared with WT mice. Bactericidal ability of peritoneal phagocytes such as neutrophils and macrophages was consistently attenuated in CX3CR1−/− mice compared with WT mice. Moreover, when WT macrophages were stimulated in vitro with CX3CL1, their bactericidal activity was augmented in a dose-dependent manner, with enhanced iNOS gene expression and subsequent NO generation. Furthermore, CX3CL1 enhanced the gene expression of IL-1β, TNF-α, IFN-γ, and IL-12 by WT macrophages with NF-κB activation. Thus, CX3CL1-CX3CR1 interaction is crucial for optimal host defense against bacterial infection by activating bacterial killing functions of phagocytes, and by augmenting iNOS-mediated NO generation and bactericidal proinflammatory cytokine production mainly through the NF-κB signal pathway, with few effects on macrophage infiltration.

Background. A potent eosinophil chemotactic cytokine, human eotaxin, is directly chemotactic for eosinophils. Therefore, the specific expression of eotaxin in tissue might play a crucial role in tissue eosinophilia. However, the precise molecular mechanism of the Introduction recruitment and activation of eosinophils in human renal diseases remains to be investigated. We evaluated Eosinophils play an important role in various types of the role of eotaxin in the pathogenesis of human diVuse human disease including allergic, inflammatory, maliginterstitial nephritis with marked infiltration of nant and cardiovascular disorders [1]. In contrast, eosinophils. aberrantly activated eosinophils release toxic cationic Methods. In this study, we examined 20 healthy volun- proteins to induce tissue destruction [1]. Eosinoteers, 56 patients with primary or secondary glomerular phils produce cytokines [interleukin (IL)-3, IL-5 and diseases and two hypereosinophilic syndrome patients granulocyte-macrophage colony stimulating factor without renal involvement. Urinary and serum eotaxin (GM-CSF )] and lipid mediators (platelet-activating levels were determined by an enzyme-linked immuno- factor, leukotrien B4), which contribute to the sorbent assay. We also detected the presence of eotaxin inflammatory processes [1]. Therefore, an imbalance protein immunohistochemically. towards excess activation may lead to tissue destrucResults. On the one hand, urinary levels of eotaxin tion. In addition, since eosinophils are circulating were significantly higher before the initiation of gluco- leukocytes, some mediators would be necessary to corticoid administration in the patient with interstitial regulate eosinophil—endothelial cell interaction, nephritis with marked infiltration of eosinophils. On resulting in the infiltration and activation of eosinophils the other hand, urinary eotaxin levels were not detected in the tissue. However, the precise molecular mechanin any patients with nephrotic syndrome, interstitial ism of the recruitment and activation of tissue eosinonephritis without eosinophils, hypereosinophilic syn- phils remains to be investigated. drome without renal involvement or other renal dis- A chemokine, human eotaxin, has been reported to eases. Serum eotaxin levels were not detected in any be an early response gene of cytokine-stimulated epiof the patients. Therefore, the detection of eotaxin in thelial and endothelial cells, and is expressed in leukothe urine was specific for renal interstitial eosinophilia. cytes including eosinophils [2,3]. Eotaxin is directly Moreover, endothelial cells, infiltrating mononuclear chemotactic for eosinophils, but not mononuclear cells cells and renal epithelial cells in the tubulointerstitial or neutrophils. Thus, the specific expression of eotaxin lesions were immunostained with specific anti-eotaxin in the tissue might play a crucial role in tissue eosinoantibodies. Furthermore, the elevated urinary levels of philia accompanied by the activation of adhesion moleeotaxin decreased dramatically during glucocorticoid- cules. Recent studies indicate that eotaxin is expressed induced convalescence. in some organs including kidneys [2]. However, the Hypothesis. We hypothesize that in situ expression of role of eotaxin in the pathogenesis of human renal eotaxin may provide a new mechanism to explain the diseases has not yet been investigated. renal interstitial eosinophil infiltration. In order to examine whether locally produced eotaxin participates in the pathophysiology of human renal diseases by recruiting and activating eosinophils

Leukocytes, particularly neutrophils, infiltrate into female genital organs after ovulation in both humans and mice. In mice, a female sexual cycle consists of 5 phases: proestrus, estrus, metestrus-1, metestrus-2, and diestrus. Ovulation occurs at estrus; at metestrus-2, a large number of neutrophils infiltrate into the vaginal epithelium accompanied by an increased neutrophil number in vaginal lavage fluid. Concomitantly, concentrations of a functional IL-8 homologue, murine macrophage inflammatory protein (MIP)-2, were increased significantly in vaginal lavage fluid at metestrus-2 as compared with other phases. On the contrary, MIP-2 was not detected in plasma during the whole course of a sexual cycle. Moreover, immunohistochemical analyses demonstrated that MIP-2 protein expression was prominent at the upper layer of the vaginal epithelium at metestrus-2, in contrast to a marginal staining in the vaginal epithelium at proestrus and estrus. These results suggest that a C-X-C chemokine, MIP-2, was produced physiologically in the vaginal epithelium in a sexual cycle-dependent manner. Furthermore, the administration of neutralizing anti-IL-8R homologue Abs at proestrus abrogated leukocyte infiltration into the vagina at metestrus. However, anti-MIP-2 Abs reduced leukocyte influx at metestrus by ∼50%. Thus, a murine IL-8 homologue, MIP-2, and its related molecules physiologically regulate neutrophil migration into the vagina in a sexual cycle-dependent manner.