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Biomedical subjects

M Ceska

Publications and source records attributed to M Ceska.

At least 55 records · Page 3Linked to original sources
PubMed1992

Human neutrophil activating peptide/interleukin 8 acts as an autoantigen in rheumatoid arthritis.

Human neutrophil activating peptide/interleukin 8 (NAP-1/IL-8) has been shown to activate neutrophils to degranulate in vitro and to be a potent chemotactic agonist for neutrophils and lymphocytes in vitro and in vivo. It may therefore be a mediator of inflammatory conditions such as rheumatoid arthritis (RA). Levels of NAP-1/IL-8 were low or undetectable in serum samples from 53 patients with RA. Circulating levels of antibodies to NAP-1/IL-8 showed a strong correlation with the level of quantified C reactive protein and with the number of arthritic joints. These autoantibodies, in a similar manner to quantified C reactive protein, correlated with disease activity and are associated with a lack of clinical improvement when the patient is treated with systemic steroids. This observation indicates an important role for interleukin 8 and its autoantibodies in the inflammatory processes of RA, and may provide a clinically useful marker for the diagnosis of disease severity.

Adult↗
PubMed1992

Neutrophil attractant protein-1-immunoglobulin G immune complexes and free anti-NAP-1 antibody in normal human serum.

After obtaining data indicating the presence of a neutrophil attractant protein-1 (NAP-1)-IgG complex in normal human serum, we developed sandwich ELISAs that could quantify NAP-1 and NAP-1-IgG in mixtures of the two moieties. The ELISA for free NAP-1 used a monoclonal capture antibody that did not bind NAP-1-IgG. The ELISA for NAP-1-IgG was based on omission of the anti-NAP-1 detection antibody (required for the free NAP-1 ELISA) and on interaction of phosphatase-conjugated anti-human IgG with the human NAP-1-IgG complex. Gel filtration of immunoaffinity-purified NAP-1-IgG showed that the bulk of the complex comprised a single IgG. Binding between NAP-1 and antibody is strong, since 8 M urea at neutral or alkaline pH did not release NAP-1. However, at pH 2.0 in 9 M urea approximately 15% of the total NAP-1 could be dissociated from the complex. NAP-1-IgG was detected in 18 of 26 sera from normal humans. The mean serum concentration was 58 ng of IgG-bound NAP-1/ml, with an SEM of 16 and a range from undetectable to 247 ng/ml. NAP-1-IgG concentrations in paired sera drawn at a 1-mo interval were remarkably constant. Using an ELISA for free NAP-1 with a detection limit of 200 pg/ml, we found no free NAP-1 in the 26 sera. Free anti-NAP-1-IgG autoantibody was found in 9 of 26 sera by direct ELISA. IgG anti-NAP-1 of all nine sera was polyclonal, comprising both kappa and lambda isotypes; predominant subclasses were IgG2 and IgG3. NAP-1-IgG did not compete with 125I-NAP-1 for binding to neutrophils, which suggests that IgG anti-NAP-1 is a molecular trap that prevents binding of NAP-1 to neutrophils after it diffuses from production sites into the circulation.

Antibodies, Monoclonal↗
PubMed1991

Detection of interleukin 8 and tumor necrosis factor in normal humans after intravenous endotoxin: the effect of antiinflammatory agents.

Interleukin 8 (IL-8), a potent activator of neutrophils, may be important in the early host response to serious Gram-negative infections. IL-8 was measured with other acute phase cytokines (tumor necrosis factor alpha [TNF-alpha], IL-6 and IL-1 beta) in 25 normal humans randomized to receive either intravenous endotoxin alone or endotoxin after oral administration of ibuprofen or pentoxifylline, agents that alter some of the inflammatory responses induced by endotoxin in vitro. TNF immunoreactivity was maximum at 1.5 h, and total TNF (area under the curve) was 4.2- and 4.5-fold greater in subjects given endotoxin/ibuprofen compared to subjects given endotoxin alone (p = 0.026) or endotoxin/pentoxifylline (p = 0.004), respectively. IL-6 levels were maximum at 2-3 h and did not differ among the three groups. No IL-1 beta was detected in any subject. IL-8 levels peaked at 2 h in subjects given either endotoxin alone or endotoxin/pentoxifylline, falling towards baseline by 5 h. Subjects given endotoxin/ibuprofen had a more sustained rise in IL-8 with peak levels 2.8- and 2.5-fold higher at 3 h compared to endotoxin alone (p = 0.048) or endotoxin/pentoxifylline (p = 0.023), respectively. Differences in total IL-8 release among groups approached statistical significance (ANOVA, p = 0.07). This trend reflected the increased release of IL-8 by the subjects receiving ibuprofen compared to pentoxifylline (1.9-fold higher; p = 0.024). This suggests that cyclooxygenase products may provide important negative feedback loops for cytokine production in vivo. Increases in circulating IL-8 are part of the acute inflammatory response of humans to endotoxin. Altered cytokine responses caused by antiinflammatory therapy may have important implications for both host defense and injury during septicemia.

Adult↗
PubMed1991

Phagocytosing neutrophils produce and release high amounts of the neutrophil-activating peptide 1/interleukin 8.

After phagocytosis of yeast opsonized with IgG, neutrophil leukocytes (polymorphonuclear leukocytes [PMN]) expressed high levels of neutrophil-activating peptide 1/interleukin 8 (NAP-1/IL-8) mRNA, which peaked after 3-5 h and were still elevated after 18 h. A similar but quantitatively less prominent effect was obtained with lipopolysaccharide (LPS). After phagocytosis, but not after exposure to LPS, the PMN progressively released considerable amounts of NAP-1/IL-8 into the culture medium (18.6-50 ng/ml in 18 h). The peptide released was biologically active, as indicated by the transient elevation of cytosolic-free calcium in PMN exposed to aliquots of the culture supernatants, and desensitization by prestimulation of the cells with recombinant NAP-1/IL-8. By producing NAP-1/IL-8 at sites where they phagocytose invading microorganisms, PMN could enhance the recruitment of new defense cells.

Calcium↗
PubMed1991

Neutrophil attractant/activating peptide-1/interleukin-8 in term and preterm parturition.

The neutrophil is the leukocyte most frequently recruited into the amniotic fluid in cases of microbial invasion of the amniotic cavity. Neutrophil attractant/activating peptide-1/interleukin-8 is a newly identified cytokine that is capable of inducing selective neutrophil chemotaxis and activation. The purpose of this study was to examine the relationship between amniotic fluid concentrations of neutrophil attractant/activating peptide-1/interleukin-8, microbial invasion of the amniotic cavity, and parturition (term and preterm). Amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8 was measured with an immunoassay validated for human amniotic fluid (sensitivity 0.3 ng/ml). Fluid was obtained from women in the following groups: midtrimester (n = 38), term not in labor (n = 38), term in active labor (n = 67), and preterm labor with intact membranes (n = 62). Fluid was cultured for aerobic and anaerobic bacterial and Mycoplasma. Sterile amniotic fluid from most women in the midtrimester of pregnancy and women at term not in labor did not contain immunoreactive neutrophil attractant/activating peptide-1/interleukin-8. Microbial invasion of the amniotic cavity was associated with increased concentrations of neutrophil attractant/activating peptide-1/interleukin-8. The amniotic fluid of women with preterm labor and sterile amniotic fluid who had preterm delivery contained higher neutrophil attractant/activating peptide-1/interleukin-8 levels than did the amniotic fluid of women who responded to tocolysis and had delivery at term. Term parturition is associated with increased concentrations of neutrophil attractant/activating peptide-1/interleukin-8 in the amniotic fluid. We conclude that neutrophil attractant/activating peptide-1/interleukin-8 is part of the host response to microbial invasion of the amniotic cavity and that increased amniotic fluid availability of this cytokine occurs in term and preterm parturition.

Adult↗
PubMed1991

Cytokine-activated human mesangial cells generate the neutrophil chemoattractant, interleukin 8.

Human mesangial cells (MC) in culture, when stimulated by interleukin 1 alpha(IL-1 alpha) or tumour necrosis factor (TNF alpha), but not with lipopolysaccharide (LPS), express interleukin 8 (IL-8) mRNA, and both cell associated and extracellular IL-8. Dexamethasone treatment of mesangial cells induced partial inhibition of the release of extracellular IL-8, while cell-associated IL-8 and IL-8 mRNA were not significantly altered. We propose that the mesangial cell has a direct role in the initiation and propagation of inflammatory events within the glomerulus via the generation of the chemotactic cytokine IL-8.

Cells, Cultured↗
PubMed1991

Interleukin-1 beta stimulates human mesangial cells to synthesize and release interleukins-6 and -8.

Interleukin-1 beta (IL-1 beta) and tumor necrosis factor (TNF) have been reported to stimulate human mesangial cells (HMC) to proliferate and synthesize eicosanoids. We have examined whether they also induce HMC to release cytokines. In this study we show that both IL-1 and TNF stimulate HMC to release IL-6 and IL-8. Cycling and quiescent HMC were stimulated with various concentrations of either recombinant IL-1 beta or TNF for 1 to 24 hours. IL-1 beta at doses as low as 6 pg/ml stimulated mesangial cells to synthesize mRNA for both IL-6 and IL-8 as assessed by Northern analysis; mRNA for tubulin remained constant, which demonstrated a specific increase in mRNA. Secretion of IL-6 and IL-8 into the culture medium increased (4.5 to 18 ng/ml and 4 to 40 ng/ml, respectively) measured by ELISAs. TNF had similar effects but only in high concentrations (greater than 100 ng/ml). IL-1 beta did not stimulate cells to proliferate, as measured by 3H thymidine incorporation. TNF caused proliferation but only in concentrations over 100 ng/ml. We conclude that IL-1 beta is a potent stimulator of human mesangial cell production of IL-6 and IL-8, both of which may influence injury in nephritis. TNF also stimulates mesangial cells but only in pharmacological doses.

Cells, Cultured↗
PubMed1991

Plasma neutrophil-activating peptide-1/interleukin-8 and neutrophil elastase in a primate bacteremia model.

A hyperdynamic sepsis model was set up in seven adult baboons to evaluate neutrophil-activating peptide-1/interleukin (IL)-8 (NAP-1/IL-8), IL-1 beta, IL-6, tumor necrosis factor-alpha (TNF alpha), and IFN-gamma in plasma. By continuous intravenous administration of 10(10) cfu/kg live Escherichia coli over 8 h with additional infusion therapy (less than or equal to 50 ml/kg/h), endotoxin plasma levels of 2.7-22.3 ng/ml were observed. In plasma the kinetics of NAP-1/IL-8 and IL-6 were similar to those of IL-1 at the end of the experiment (8 h) (peak median values, 34, 4197, and 230 ng/ml, respectively). Differences were greatest for IL-6. Monocyte activation during sepsis was confirmed by elevated plasma neopterin levels (91-139 mumol/mmol of creatine). Granulocyte activation was evident from both incipient neutropenia and the massive release of neutrophil elastase into the plasma as measured by a new immunoassay (peak level, 374 ng/ml). Thus, in primate bacteremia, early TNF release is followed by a concomitant increase of NAP-1/IL-8 with plasma kinetics similar to those of IL-6 and IL-1 and accompanied by massive activation of neutrophils.

Animals↗
PubMed1991

Presence of NAP-1/IL-8 in synovial fluids indicates a possible pathogenic role in rheumatoid arthritis.

The synovial fluid in affected joints of rheumatoid arthritis (RA) patients contains many cells, in numbers strongly correlated with the severity of disease. As the disease worsens and the cell count increases, the polymorphonuclear leucocyte becomes the predominant cell type. Although the inflammatory cytokines interleukin 1 (IL-1) and tumour necrosis factor (TNF) have no direct neutrophil-attractant activity, they are both potent inducers of interleukin 8 (IL-8) in a variety of cell types. Chemotactic attraction of neutrophils is a major activity of IL-8. Examination of a number of synovial fluids showed that significant levels of IL-8 are present in a high proportion of RA cases (10 out of 17), at concentrations directly related to the number of cells in the joint, and to circulating C-reactive protein (CRP) levels. The cytokine is present only at background levels in other diseases accompanied by arthritic manifestations, including systemic lupus erythematosus (SLE) and induced arthritis. The progressive joint destruction seen in all cases where high IL-8 levels were measured, coupled with the neutrophil-rich cell count and the strong correlation between concentration of IL-8 and both serum CRP and cellular influx into the joint, is strongly suggestive of a pathogenic role for IL-8 in RA.

Arthritis, Rheumatoid↗
PubMed1991

Human neutrophil migration into skin chambers is associated with production of NAP-1/IL8 and C5a.

Respiratory burst activity initiated by the chemoattractants fMLP, rC5a and rNAP-1/IL8 was investigated in human exudated and peripheral blood neutrophils. Exudated cells were isolated after migration into a skin chamber and the respiratory burst activity was measured as chemiluminescence amplified by luminol and horseradish peroxidase. The response to fMLP (5 x 10(-8) mol/l) was significantly enhanced (p less than 0.01) in the exudated cells but was significantly decreased after stimulation (5 x 10(-8) mol/l) with rC5a and rNAP-1/IL8 (p less than 0.05 and p less than 0.01, respectively). Analysis revealed that, in the chamber fluid, the activated complement C5a was generated during exudation (p less than 0.01). Determinations of NAP-1/IL8 showed that this substance was also produced and released into the chamber fluid (p less than 0.01). No correlation was found between the number of exudated cells and the amount of C5a or NAP-1/IL8 in the exudation fluid, thus indicating that, in vivo, the exudation process is controlled by multiple factors and not by the quantity of a single chemoattractant. The present study shows that NAP-1/IL8 and C5a are produced in humans during an aseptic inflammation, and that this occurs in parallel to the migration of neutrophils into the skin chambers. The significant desensitization of the exudated cells to NAP-1/IL8 and C5a reflects a previous exposure to these attractants. These results suggest that the novel tissue-derived cytokine NAP-1/IL8 plays a role in human neutrophil exudation in vivo.

Cell Movement↗
PubMed1991

Secretory repertoire of HIV-infected human monocytes/macrophages.

Apart from lymphocytes, mononuclear phagocytes play an essential role as target cells for human immunodeficiency virus (HIV). Circulating blood monocytes (MOs) and tissue macrophages (M phi) may harbor and distribute the virus throughout the body. In addition, proinflammatory monokines [interleukin-1 (IL-1), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha)] may contribute to the pathogenesis of HIV-mediated diseases. We have established a culture system on hydrophobic Teflon membranes for blood-borne MOs/M phi. Both freshly isolated MOs as well as MO-derived M phi could be infected with a monocytotropic HIV-1 isolate (HIV-1D117III) derived from a perinatally infected child. The virus production monitored by assay for viral antigen in cell-free supernatant is continuous for several weeks. We analyzed the stimulus response and the secretory repertoire of MOs/M phi early after infection with HIV as well as in long-term cultured, virus-replicating cells. Infected MOs/M phi respond to interferon-gamma more effectively than control cells as estimated from the release of neopterin. The response to lipopolysaccharide was regulated differently: whereas the proinflammatory cytokines IL-1, IL-6, IL-8 and TNF-alpha were up-regulated and even constitutively secreted upon infection, the production of the hematopoietin macrophage-colony-stimulating factor decreased. High levels of TNF-alpha and IL-1 might augment the infectibility of M phi by HIV in an autocrine manner. Our results may provide some explanation for the immunologic dysfunction, the hematopoietic failure and the chronic inflammatory disease occurring in HIV-infected patients.

Biopterins↗
PubMed1991

Recombinant human interleukin 6 is a potent inducer of the acute phase response and elevates the blood platelets in nonhuman primates.

Human interleukin 6 (IL-6) produced by molecular cloning was administered to nonhuman primates to assess its biological activities in vivo. Rhesus monkeys were treated s.c. with recombinant human (rh) IL-6 at 3 and 30 micrograms/kg body weight/day for 11 days, followed by the administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) at 5.5 micrograms/kg/day for 5 days. Serum levels of positively regulated acute phase proteins (APP) (C-reactive protein, alpha 1-antitrypsin, haptoglobin, and ceruloplasmin) increased, whereas negatively regulated APP (prealbumin) decreased in response to rhIL-6 treatment in a dose-dependent manner. Platelet counts rose after a latent period of 4-5 days following the start of rhIL-6 treatment, resulting in a maximum twofold increase above normal levels 2-3 days after the termination of the rhIL-6 treatment. Recombinant human IL-6 treatment induced a two to threefold rise in myeloid progenitor blood cell levels. The subsequent administration of rhGM-CSF to rhIL-6-pretreated animals did not increase the progenitor cell levels in blood above those found with rhGM-CSF treatment alone, indicating that rhIL-6 compared to recombinant human interleukin 3 (rhIL-3) has a minor proliferative effect on hematopoietic precursors in vivo. In conclusion, rhIL-6 was shown to be a potent stimulator of APP and was able to increase the number of platelets in circulation in nonhuman primates.

Acute-Phase Reaction↗
PubMed1981

Binding of protein A to some human gamma-globulins used intravenously.

We examined the binding capacity of radioiodinated protein A ([125I]PA) for several human IgG immunoglobulins. Most of them are commercial preparations used in immunosubstitution therapy. Two experimental approaches were chosen. In the first, the binding of [125I] PA to solidified IgG preparations was studied. In the second approach, the inhibition of [125I] PA binding to a given immunoglobulin by various human immunoglobulin samples was established. Both the binding and inhibition criteria were used to estimate the order of the relative binding capacities of the Fc region in studied IgG preparations. The various commercial gamma-globulin preparations were also compared using single radial immunodiffusion and cross-immunoelectrophoretic techniques.

Chromatography, Gel↗
PubMed1978

Solid-phase radioimmunoassay method for determination of Escherichia coli enterotoxin.

The development of a solid-phase radioimmunoassay procedure for the determination of Escherichia coli enterotoxin(s) is described. Radioiodinated E. coli enterotoxin with about three radioiodine atoms per toxin molecule is, by the criterion of electrophoresis, identical to the unlabeled toxin. Goat anti-E. coli-enterotoxin antibody was coupled to polystyrene tubes and served as a solified toxin binder in the reported procedure. Various conditions necessary for the optimization and standardization of the solid-phase method were established. With the help of this technique it was possible to determine E. coli enterotoxin released from a porcine E. coli strain into culture medium.

Bacterial Toxins↗