Biomedical subjects

N Mukaida

Publications and source records attributed to N Mukaida.

At least 91 records · Page 5Linked to original sources

PubMed1997

Inhibition of immature erythroid progenitor cell proliferation by macrophage inflammatory protein-1alpha by interacting mainly with a C-C chemokine receptor, CCR1.

Several lines of evidence indicate that macrophage inflammatory protein-1alpha (MIP-1alpha) modulates the proliferation of hematopoietic progenitor cells, depending on their maturational stages. To clarify the mechanisms for the modulation of hematopoiesis by this chemokine, we examined the expression of a receptor for MIP-1alpha, CCR1, on bone marrow cells of normal individuals using a specific antibody and explored the effects of MIP-1alpha on in vitro erythropoiesis driven by stem cell factor (SCF) and erythropoietin (Epo). CCR1 was expressed on glycophorin A-positive erythroblasts in addition to lymphocytes and granulocytes. CCR1+ cells, isolated from bone marrow mononuclear cells (BMMNCs) using a cell sorter, comprised virtually all erythroid progenitor cells in the BMMNCs. Moreover, MIP-1alpha inhibited, in a dose-dependent manner, colony formation by burst-forming unit-erythroid (BFU-E), but not by colony forming unit-erythroid (CFU-E), in a methylcellulose culture of purified human CD34+ bone marrow cells. Although reverse-transcription polymerase chain reaction (RT-PCR) showed the presence of CCR1, CCR4, and CCR5 transcripts in CD34+ cells in BM, anti-CCR1 antibodies significantly abrogated the inhibitory effects of MIP-1alpha on BFU-E formation both in a methylcellulose culture and in a single cell proliferation assay of purified CD34+ cells. Although the contribution of CCR4 or CCR5 cannot be completely excluded, these results suggest that MIP-1alpha-mediated suppression of the proliferation of immature, but not mature erythroid progenitor cells, is largely mediated by CCR1 expressed on these progenitor cells.

Analysis of Variance↗

PubMed1997

Interleukin-8 selectively enhances cytopathic effect (CPE) induced by positive-strand RNA viruses in the human WISH cell line.

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.

2',5'-Oligoadenylate Synthetase↗

PubMed1997

The differential ability of IL-8 and neutrophil-activating peptide-2 to induce attenuation of chemotaxis is mediated by their divergent capabilities to phosphorylate CXCR2 (IL-8 receptor B).

IL-8 and neutrophil-activating peptide-2 (NAP-2) are two closely related C-X-C chemokines that differ in their abilities to induce chemotaxis of human polymorphonuclear leukocytes (PMN). Although two IL-8R types are expressed by PMN, only CXCR2 binds NAP-2 and IL-8 with equally high affinity. By using enriched CXCR2-transfected 293 cells, we show that high doses of IL-8 induce attenuation of chemotaxis, while equivalent doses of NAP-2 do not. Phosphorylation analysis shows that IL-8 induces higher levels of phosphorylation of the carboxyl terminus of CXCR2 than does NAP-2, suggesting that the level of phosphorylation contributes to the ability of the chemokines to attenuate the chemotactic response. To directly evaluate this difference, we analyzed the ability of receptors mutated to delete regions that highly express potential phosphorylation sites to be phosphorylated and to mediate chemotactic attenuation. We found that a carboxyl terminus-truncated mutant of CXCR2 was not phosphorylated by high doses of IL-8, as determined by in vivo phosphorylation assays and by analysis of the electrophoretic mobility of the receptors on SDS-PAGE gels. This mutated receptor had a significantly lower ability to attenuate IL-8-induced chemotaxis, indicating that the attenuation of chemotaxis is mediated by chemokine-induced receptor phosphorylation. In conclusion, the data show that the greater ability of IL-8 to induce receptor phosphorylation contributes to its more potent attenuation of chemotaxis as compared with NAP-2. This differential phosphorylation by IL-8 and NAP-2 of CXCR2 provides a basis for the divergent outcome of PMN-induced inflammation in response to these two closely related C-X-C chemokines.

Cells, Cultured↗

PubMed1997

Stimulation of interleukin-8 production by okadaic acid and vanadate in a human promyelocyte cell line, an HL-60 subline. Possible role of mitogen-activated protein kinase on the okadaic acid-induced NF-kappaB activation.

Most types of cells can produce interleukin (IL)-8 in response to various inflammatory stimuli. To study the role of protein phosphatases in the signal transduction leading to IL-8 production, a subline of HL-60 (C-15) was treated with okadaic acid (OA) and sodium orthovanadate (VA), inhibitors of phosphoserine/phosphothreonine phosphatase and phosphotyrosine phosphatase, respectively. Both OA and VA dramatically increased IL-8 secretion up to 200-fold in the HL-60 cells. OA and VA stimulation was accompanied by a marked increase in IL-8 mRNA expression and also by activation of a transcription factor, NF-kappaB. In addition, an essential role of the NF-kappaB site in the IL-8 gene activation was confirmed by the chloramphenicol acetyltransferase assay. IL-8 production by OA or VA was inhibited by protein kinase inhibitors, including staurosporine, H-7, K252a, herbimycin A, and genistein. Both OA and VA induced significant tyrosine phosphorylation of p44, which was presumed to be Erk1, a member of the mitogen-activated protein kinase family, with concomitant activation of the mitogen-activated protein kinase activity. In parallel, rapid degradation of IkappaB-alpha, an inhibitory component of NF-kappaB, was observed. Since OA-activated Erk1 phosphorylated recombinant IkappaB-alpha in vitro, we assumed that Erk1 is involved in the phosphorylation and subsequent degradation of IkappaB-alpha, thus leading to the activation of IL-8 gene transcription.

Base Sequence↗

PubMed1997

Combined therapy of multidrug-resistant human lung cancer with anti-P-glycoprotein antibody and monocyte chemoattractant protein-1 gene transduction: the possibility of immunological overcoming of multidrug resistance.

We determined whether transduction of the monocyte chemoattractant protein-1 (MCP-1) gene into MDR human lung cancer cells affected their tumorigenicity and sensitivity to antibody-dependent cellular cytotoxicity (ADCC) reaction mediated by the anti-P-glycoprotein (P-gp) monoclonal antibody MRK16. The human MCP-1 gene inserted into an expression vector (BCMGSNeo) was transfected into MDR human small-cell lung cancer (H69/VP) cells. Monocyte chemotactic activity was found in culture supernatants collected from MCP-1-transfected H69/VP cells, but not in supernatants of parent and mock-transfected cells. In an in vitro experiment, recombinant MCP-1 did not affect monocyte-mediated ADCC against H69/VP cells when added to the monocyte culture in either the activation or the effector phase at sufficient concentrations to attract and activate monocytes. Tumorigenicity and growth rates of MCP-1-producing H69/VP cells in nude mice were similar to those of parental cells and mock-transfected cells. However, systemic treatment with MRK16 was more effective in inhibiting the formation of tumors by MCP-1-gene-transfected cells than by mock-transfected cells. Systemic treatment with MRK16 also inhibited the growth of a mixture (1:1) of MCP-1-producing cells and mock-transfected cells. These results suggest that combination therapy with MRK16 and MCP-1 gene transduction may be a useful immunological strategy to inhibit the growth of human MDR cancer cells expressing P-gp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Chemotaxis and IL-8 receptor expression in B cells from normal and HIV-infected subjects.

To date, the activities of the alpha chemokines for human peripheral B cells from normal subjects (N-B cells) or from HIV-infected subjects (HIV-B cells) are not well established. No report on the IL-8R expression on N-B cells and HIV-B cells has been seen. We report in this work that the alpha chemokines IL-8 and growth-regulatory oncogene-alpha (GRO-alpha) induce a chemotactic migration of N-B cells and HIV-B cells via stimulating the IL-8RB on these cells. The chemotaxis of N-B cells can be inhibited by IFN-gamma and IL-2, and augmented by IL-4 and IL-13, whereas TNF-alpha and IL-10 have no influence. The chemotaxis of HIV-B cells can be inhibited by IFN-gamma and IL-2, and augmented by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. IL-8R are expressed more abundantly on freshly isolated HIV-B cells than N-B cells (51% and 15%, respectively). The IL-8R on N-B cells can be down-regulated by IFN-gamma, IL-2, and TNF-alpha (selectively on IL-8RA), and up-regulated by IL-4 and IL-13, whereas IL-10 has no influence. The IL-8R on HIV-B cells can be down-regulated by IFN-gamma and IL-2, and up-regulated by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. Importantly, N-B cell and HIV-B cell chemotaxis toward IL-8 and GRO-alpha can be blocked by anti-IL-8RB polyclonal Ab, but not by anti-IL-8RA polyclonal Ab. Our results demonstrate that IL-8 and GRO-alpha are important inflammatory mediators that stimulate the directional migration and recruitment of B lymphocytes. The migratory behavior and the expression of IL-8R on HIV-B cells and some of the reactions to Th1- and Th2-like cytokines are modified significantly during HIV infection.

Adult↗

PubMed1997

Prevention of adenocarcinoma colon 26-induced cachexia by interleukin 10 gene transfer.

A s.c. injection of a mouse colon adenocarcinoma cell line, colon 26 clone 20, induced cachexia, as evidenced by progressive weight loss and severe hypoglycemia. Several lines of evidence indicate that a pro-inflammatory cytokine, interleukin 6 (IL-6), plays a major role, albeit partially, in the establishment of cachexia in this model. Because IL-10 can potentially inhibit the production of pro-inflammatory cytokines including IL-6, we evaluated the effects of IL-10 gene transfer on the establishment of cachexia. IL-6 transcript was detected at tumor sites of mice inoculated with parental or control vector transfectant cells, and serum IL-6 levels were markedly increased in these mice. The injection of parental cells into IL-6-deficient mice induced cachexia with elevated serum IL-6 levels comparable to wild-type mice, indicating that tumor cells are a major source of IL-6. The inoculation of IL-10-transfectant cells kept IL-10 mRNA expression at tumor sites and induced the elevation in serum IL-10 levels without affecting the growth rates of colon 26 cells both in vitro and in vivo. However, the implantation with IL-10-transfectant cells reduced the expression of IL-6 mRNA at the tumor sites and the elevation in serum IL-6 levels. Concomitantly, mice inoculated with IL-10-transfectant cells did not exhibit progressive weight loss, a reduction in food intake, or severe hypoglycemia, which was observed in mice inoculated with parental or control vector-transfectant cells. Collectively, these results suggest that IL-10 gene transfer prevented the occurrence of cachexia with a concomitant inhibition of IL-6 production at the tumor sites.

Animals↗

PubMed1997

Attenuation of monosodium urate crystal-induced arthritis in rabbits by a neutralizing antibody against interleukin-8.

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 ofleukocytes, 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.

Animals↗

PubMed1997

Enhanced mobilization of hematopoietic progenitor cells by mouse MIP-2 and granulocyte colony-stimulating factor in mice.

Human interleukin-8 (IL-8) induces a rapid mobilization of hematopoietic progenitor cells (HPCs) into peripheral blood in mice and primates. Because an exact homologue of human IL-8 does not exist in mice, a chemokine, macrophage inflammatory protein-2 (MIP-2), is supposed to substitute the function of IL-8 in mice. Hence, we investigated the capacity of mouse MIP-2 to induce HPC mobilization in mice. Mouse MIP-2 induced, in either untreated or splenectomized mice, a rapid HPC mobilization, as evidenced by increased numbers of colony-forming unit granulocyte-macrophage (CFU-GM) and lineage marker (Lin)-c-kit+Sca-1+ cells. Although release of elastase from activated neutrophils was proposed to be involved in IL-8-induced HPC mobilization, mouse MIP-2 induced similar levels of HPC mobilization in elastase-deficient beige mice at a similar level to normal ones. This HPC mobilization by MIP-2 was markedly enhanced by pretreatment with granulocyte-colony-stimulating factor (G-CSF). Moreover, the combination of G-CSF and MIP-2 apparently down-regulated L-selectin expression on Lin-Sca-1+ cells in peripheral blood as well as bone marrow. Thus, MIP-2 may down-modulate the interaction between HPCs and bone marrow stroma by reducing L-selectin expression on HPCs and cause rapid mobilization of HPCs into peripheral blood.

Animals↗

PubMed1997

Pivotal role of interleukin-8 in the acute respiratory distress syndrome and cerebral reperfusion injury.

Neutrophil recruitment is one of the hallmarks of acute inflammation. A potent neutrophil chemotactic and activating factor, interleukin-8 (IL-8), has been demonstrated to be elevated in body fluids in various human diseases and experimental animal models. Recent investigations on animal disease models using blocking antibodies to IL-8 have revealed the essential involvement of IL-8 in acute inflammation. We previously reported that the administration of a neutralizing antibody against IL-8 prevented the neutrophil infiltration and neutrophil-mediated tissue injury in several animal studies. In addition, we have recently demonstrated that anti-IL-8 treatment is also effective in prevention of two models that are very relevant to clinical situations: cerebral reperfusion injury and endotoxemia-induced acute respiratory distress syndrome-like lung injury. These results further support the hypothesis that IL-8 has a pivotal role and is a novel target for therapeutic intervention in neutrophil-mediated injury.

Animals↗

PubMed1997

Anti-interleukin-8 monoclonal antibody reduces free radical production and improves hemodynamics and survival rate in endotoxic shock in rabbits.

BACKGROUND: Although high levels of interleukin-8 (IL-8) have been found in patients with sepsis and a monoclonal antibody (MoAb) against IL-8 has been successfully used in some animal models of inflammation, no specific therapeutic agent against IL-8 has been tested for the treatment of sepsis. We studied the effects of a MoAb against IL-8 in the treatment of endotoxic shock with a prospective randomized rabbit endotoxic shock model. METHODS: Twenty New Zealand white rabbits were anesthetized and divided into four groups: normal, anti-IL-8, control-Ab, and lipopolysaccharide (LPS). Anti-IL-8 and control-Ab groups received a MoAb (immunoglobulin G, 3 mg/kg) 5 minutes before the LPS injection. All groups, except the normal group, received a continuous 20-minute infusion of LPS (500 micrograms/kg). The normal group received NaCl (0.9%) rather than LPS. RESULTS: The 7-day survival rates were 100% for normal group, 80% for anti-IL-8 group, 40% for control-Ab group, and 0% for LPS group. Compared with the LPS group, anti-IL-8 rabbits had a smaller decrease in mean arterial blood pressure (p < 0.05) and increased urinary volume (p < 0.05). Anti-IL-8 rabbits had lower plasmatic levels of IL-1 beta, less free radical production (p < 0.05), and a higher survival rate (p < 0.01). CONCLUSIONS: IL-8 plays a significant role in endotoxic shock, and IL-8 blockage results in attenuation of the hypotensive and tachypneic effects of LPS, reduced free radical production, and an increased survival rate after lethal endotoxic shock.

Animals↗

PubMed1997

Effect of thromboxane A2 antagonists on bronchial hyperresponsiveness induced immediately after interleukin-8 inhalation in guinea-pigs.

1. Although repeated intranasal administration of interleukin-8 (IL-8) causes bronchial hyperresponsiveness (BHR) mediated via thromboxane A2 (TXA2) and airway neutrophil accumulation in guinea-pigs, the acute effect of inhaled IL-8 is unclear. We performed this study to clarify the acute effect of IL-8 on bronchial responsiveness and the role of TXA2. 2. The effects of inhaled IL-8 on bronchial responsiveness and of the TXA2 antagonists, S-1452 (0.01 and 0.1 mg kg-1) and ONO-NT-126 (1.0 or 10 micrograms kg-1), on IL-8-induced BHR were examined by use of a modified Konzett-Rössler method in guinea-pigs. 3. Inhaled IL-8 at 100 ng ml-1, which failed to induce significant changes in Pao (pressure at the airway opening), enhanced an increase in Pao induced by subsequent inhalations of ascending doses (50-200 micrograms ml-1) of methacholine and histamine, suggesting the potentiating effect of IL-8 on bronchial responsiveness. No significant leukocyte infiltration was observed histologically sixteen minutes after the IL-8 inhalation. Both S-1452 and ONO-NT-126 reduced the IL-8-induced BHR. 4. In conclusion, IL-8 rapidly causes BHR via TXA2 release in guinea-pigs.

Administration, Inhalation↗

PubMed1997

Intervention in endotoxin shock by sulfatide (I3SO3-GalCer) with a concomitant reduction in tumor necrosis factor alpha production.

Accumulating evidence indicates that tumor necrosis factor alpha (TNF-alpha) is a principal mediator of endotoxin shock. We previously reported that the action as well as the production of TNF requires the adhesion of leukocytes to the endothelium through integrin beta2 and intercellular adhesion molecule 1. In order to elucidate the roles of the initial interaction of the leukocytes with the endothelium through the selectins, we have examined the effects of a ligand for L- and P-selectins, sulfatide, on endotoxin shock in mice. Consistent with previous reports, a single injection of a high dose of endotoxin caused acute lethality, marked hypotension, leukopenia, and elevation in serum TNF-alpha levels. Pretreatment with sulfatide prevented acute lethality and hypotension, but not leukopenia, with a concomitant reduction in the increase in serum TNF-alpha levels. Moreover, pretreatment with sulfatide inhibited lipopolysaccharide (LPS)-induced TNF-alpha production by a human monocytic cell line, THP-1, in a dose-dependent manner. These results suggest either that selectin is critically involved in conferring the responsiveness of leukocytes to LPS or that sulfatide interferes with the intracellular signaling pathway which leads to TNF-alpha gene activation.

Animals↗

PubMed1997

Tumor necrosis factor receptor p55 is essential for intrahepatic granuloma formation and hepatocellular apoptosis in a murine model of bacterium-induced fulminant hepatitis.

Accumulating evidence implicates tumor necrosis factor (TNF) and Fas systems in liver injury, although the interaction between these two systems remains to be investigated. In this study, we examined Propionibacterium acnes-primed TNF receptor p55-deficient (TNFRp55-/-) or Fas-deficient MRL/MpJ Lpr/Lpr mice challenged with lipopolysaccharide (LPS). Priming with P. acnes caused mononuclear cell infiltration into the hepatic lobules and granuloma formation in the livers of TNFRp55 wild-type mice. Subsequent LPS challenge caused massive liver injury and a marked increase in transaminase levels, leading to acute lethality in control wild-type mice. In contrast, the same treatment caused few pathological changes in livers of TNFRp55-/- mice, and all animals survived. P. acnes and subsequent LPS challenge induced granuloma formation and apoptotic changes, respectively, in livers of MRL/MpJ Lpr/Lpr mice. However, liver injury was 50% of that in control MRL/MpJ +/+ mice, suggesting some role of the Fas-Fas ligand system in this liver injury model. On the other hand, an agonistic anti-Fas antibody caused massive apoptosis and hemorrhagic changes of the liver without any priming with P. acnes, leading to death in both TNFRp55-/- and control wild-type mice. These results suggest that TNFRp55 but not Fas was involved in P. acnes-induced granuloma formation as well as subsequent LPS-induced liver injury and that TNFRp55 and Fas independently induced apoptosis of hepatocytes in vivo.

Animals↗

PubMed1997

Mechanisms involved in Helicobacter pylori-induced interleukin-8 production by a gastric cancer cell line, MKN45.

Accumulating evidence suggests an important role of interleukin-8 (IL-8) in Helicobacter pylori infection-associated chronic atrophic gastritis and peptic ulcer. We observed in this study that a gastric cancer-derived cell line, MKN45, produced a massive amount of IL-8 upon coculture with live H. pylori but not with killed H. pylori, H. pylori culture supernatants, or live H. pylori separated by a permeable membrane, indicating that IL-8 production requires a direct contact between the cells and live bacteria. Moreover, the tyrosine kinase inhibitor herbimycin but neither a protein kinase C inhibitor (staurosporine) nor a protein kinase A inhibitor (H89) inhibited IL-8 production by MKN45 cells cocultured with live bacteria, suggesting the involvement of a tyrosine kinase(s) in H. pylori-induced IL-8 production. In addition, coculture of H. pylori induced IL-8 mRNA expression in MKN45 cells and an increase in luciferase activity in cells which were transfected with a luciferase expression vector linked with a 5'-flanking region of the IL-8 gene (bp -133 to +44), indicating that the induction of IL-8 production occurred at the transcriptional level. This region contain three cis elements important for induction of IL-8 gene expression: AP-1 (-126 to -120 bp), NF-IL6 (-94 to -81 bp), and NF-kappaB (-80 to -70 bp) binding sites. Mutation of the NF-kappaB binding site abrogated completely the induction of luciferase activity, whereas that of the AP-1 site partially reduced the induction. However, mutation of the NF-IL6 binding site resulted in no decrease in the induction of luciferase activity. Moreover, specific NF-kappaB complexes were detected in the nuclear proteins extracted from MKN45 cells which were infected with H. pylori. Collectively, these results suggest that H. pylori induced the activation of NF-kappaB as well as AP-1, leading to IL-8 gene transcription.

Gene Expression Regulation↗

PubMed1997

Human cytomegalovirus induces interleukin-8 production by a human monocytic cell line, THP-1, through acting concurrently on AP-1- and NF-kappaB-binding sites of the interleukin-8 gene.

Cytomegalovirus (CMV) infection induced interleukin-8 (IL-8) gene transcription in a human monocytic cell line, THP-1 cells, leading to IL-8 secretion. The functional analysis of the IL-8 gene revealed that both AP-1- and NF-kappaB factor-binding elements were involved in conferring the responsiveness to CMV. Moreover, electrophoretic mobility shift assays demonstrated that CMV induced the formation of NF-kappaB and AP-1 complexes. These results suggest that CMV activates these transcriptional factors, resulting in IL-8 gene expression.

Animals↗

PubMed1997

Identification of tumor-specific paclitaxel (Taxol)-responsive regulatory elements in the interleukin-8 promoter.

Paclitaxel (Taxol) is a novel chemotherapeutic drug that is effective against breast and ovarian cancers. Although the primary target of paclitaxel is microtubules, its efficacy exceeds that of conventional microtubule-disrupting agents, suggesting that it may have additional cellular effects. Previously, we demonstrated that paclitaxel can induce interleukin-8 (IL-8) gene expression at the transcriptional level in subsets of human ovarian cancer lines. In this as well as the previous report, we present evidence that this ability is not linked to the lipopolysaccharide pathway of IL-8 gene induction. The present study identifies the cis-acting elements and trans-acting factors involved in this induction by transfecting DNA constructs containing the 5'-flanking region of the IL-8 gene linked to the chloramphenicol acetyltransferase reporter gene into paclitaxel-responsive and nonresponsive ovarian cancer cells (responsiveness refers to the IL-8 response). Paclitaxel only activated the IL-8 promoter in responsive cells. The AP-1 and NF-kappaB binding sites in the IL-8 promoter are required for activation by paclitaxel; in contrast, a C/EBP site required for IL-8 promoter activation in other cell types is not involved. Gel shift assays demonstrate that paclitaxel causes a marked increase in protein binding to the NF-kappaB and AP-1 consensus binding sequences in the paclitaxel-responsive ovarian cells, but not the nonresponsive cells. The induction of NF-kappaB and AP-1 binding is reduced by the addition of protein kinase C inhibitors and cyclic AMP effector, respectively. These results demonstrate a molecular mechanism for cell-specific paclitaxel-induced IL-8 gene expression which may have clinical relevance.

Antineoplastic Agents, Phytogenic↗

PubMed1997

Elevated chemokine levels in bronchoalveolar lavage fluid of tuberculosis patients.

In pulmonary tuberculosis, the proportion of lymphocytes, particularly that of CD4+ T lymphocytes, was increased in bronchoalveolar lavage fluid (BALF), reflecting their protective role against mycobacterial infections. In order to elucidate the mechanisms of lymphocyte accumulation in lungs, we measured the levels of chemokines with potent lymphocyte chemotactic activities, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and, regulated on activation, normal T-cell expressed and secreted (RANTES) present in BALF from patients with pulmonary tuberculosis in acute (n = 10) and convalescent phases (n = 6), as well as normal subjects (n = 10). During the acute phase of the disease, the proportions of lymphocytes and neutrophils were increased, as reported in previous studies. The levels of IL-8, MCP-1, and RANTES in the acute phase of pulmonary tuberculosis were also markedly elevated as compared with those of normal subjects. MCP-1 and RANTES, but not IL-8 levels present in BALF, decreased in the convalescent phase. Moreover, the concentration of RANTES correlated significantly with the absolute number of CD4+ cells in BALF. These data suggest that chemotactic cytokines are differentially produced and participate in the host response to Mycobacterium tuberculosis infection.

Bronchoalveolar Lavage Fluid↗