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E V Granowitz

Publications and source records attributed to E V Granowitz.

26 records · Page 2Linked to original sources
PubMed1992

Effect of interleukin-1 (IL-1) blockade on cytokine synthesis: II. IL-1 receptor antagonist inhibits lipopolysaccharide-induced cytokine synthesis by human monocytes.

Lipopolysaccharide (LPS) stimulates interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) gene expression and synthesis in human peripheral blood mononuclear cells (PBMC). IL-1 can also induce PBMC to synthesize IL-1 and TNF alpha. In the present study, we used IL-1 receptor antagonist (IL-1ra) to determine the relative contribution of an IL-1-positive feedback loop to the total amount of LPS-induced cytokine synthesis. Pretreatment of PBMC with human recombinant IL-1ra reduced LPS-induced cytokine synthesis in a dose-dependent manner (P less than .001). Maximal inhibition was 33% for IL-1 alpha (P less than .01), 43% for IL-1 beta (P = .001), and 20% for TNF alpha (P less than .05). We consistently observed IL-1ra suppression of LPS-induced cytokines in PBMC of 38 volunteers. However, this phenomenon was not specific for LPS; 1 microgram/mL IL-1ra inhibited IL-1 beta synthesized in response to human recombinant IL-2 by 44% (P less than .001), toxic shock syndrome toxin-1 by 26% (P less than .05), and phorbol 12-myristate 13-acetate by 76% (P less than .001). IL-1ra added to PBMC 4 or 8 hours after stimulation with LPS still inhibited IL-1 beta synthesis by 44% (P less than .001) or 25% (P = .01), respectively. The steady state messenger RNA levels of IL-1 beta were reduced in PBMC stimulated by LPS in the presence of IL-1ra. In monocytes isolated by elutriation, IL-1ra reduced LPS-induced IL-1 alpha by 16% (P less than .001), IL-1 beta by 14% (P less than .05), and TNF alpha by 24% (P = .01). We conclude that IL-1-induced IL-1 significantly contributes to LPS-induced cytokine synthesis.

Cells, Cultured↗
PubMed1992

Pharmacokinetics, safety and immunomodulatory effects of human recombinant interleukin-1 receptor antagonist in healthy humans.

A phase I study of human recombinant interleukin-1 receptor antagonist (IL-1ra) was conducted in healthy males between the ages of 18 and 30. Twenty-five volunteers received a single, 3 h continuous intravenous infusion of doses ranging between 1 mg/kg and 10 mg/kg IL-1ra. At 3 h into the infusion, plasma IL-1ra levels were 3.1 micrograms/ml and 29 micrograms/ml for the 1 mg/kg and 10 mg/kg doses, respectively. Post-infusion plasma IL-1ra levels declined rapidly, exhibiting an initial half-life of 21 min and a terminal half-life of 108 min. Clinical, hematological, biochemical, endocrinological and immunomodulatory effects were monitored over 72 h and compared to those of four subjects receiving a 3 h infusion of saline. There were no clinically significant differences between the drug and saline groups in symptoms, physical examinations, complete blood counts, mononuclear cell phenotypes, blood chemistry profiles, serum iron and serum cortisol levels. Peripheral blood mononuclear cells (PBMC) obtained after completion of the IL-1ra infusion synthesized significantly less interleukin 6 ex vivo than PBMC from saline-injected controls. These data suggest that transient blockade of interleukin 1 receptors is safe and does not significantly affect homeostasis.

Cytokines↗
PubMed1992

Interleukin-1 (IL-1) receptor blockade reduces endotoxin and Borrelia burgdorferi-stimulated IL-8 synthesis in human mononuclear cells.

Interleukin-1 (IL-1) is a potent stimulator of IL-8 production by fibroblasts and monocytes. In the present study, we asked how much of endotoxin (LPS)-induced IL-8 production by human peripheral blood mononuclear cells was due to IL-1 induced by LPS. Cells were stimulated with either IL-1 beta, LPS, or Borrelia burgdorferi, and total IL-8 was determined by a specific radioimmunoassay. The addition of saturating concentrations of IL-1 receptor antagonist protein (IRAP) reduced the IL-1 beta-, LPS-, and B. burgdorferi-induced IL-8 synthesis by 85, 50, and 40%, respectively. Increasing the concentration of LPS did not affect the reduction in IL-8 synthesis observed in the presence of IRAP. Significant inhibition of the IL-1 beta-induced IL-8 synthesis was observed when IRAP was added 60 or 90 min after IL-1 beta; similarly, IL-8 synthesis after LPS was also reduced by delayed addition of IRAP. These data suggest that the ameliorative effects of IL-1 receptor blockade in models of inflammation and infection may be due, in part, to suppression of IL-1-induced IL-8.

Borrelia burgdorferi Group↗
PubMed1991

Production of interleukin-1-receptor antagonist during experimental endotoxaemia.

Interleukin-1 (IL-1) has been implicated in the pathogenesis of sepsis. IL-1-receptor antagonist (IL-1ra) is a naturally occurring inhibitor of IL-1 activity that competes with IL-1 for occupancy of cell-surface receptors but possesses no agonist activity. We induced endotoxaemia in 9 healthy human volunteers by injection of Escherichia coli endotoxin, and measured plasma concentrations of IL-1 and IL-1ra by radioimmunoassay during the next 24 h. Peak plasma concentrations of IL-1ra were about a hundred-fold greater than those of IL-1 beta. No IL-1 or IL-1ra were detectable in the plasma of 4 volunteers injected with saline. Our results suggest that the predominant natural response to endotoxin in man is the production of antagonist rather than agonist.

Adolescent↗
PubMed1991

Interleukin-1 receptor antagonist competitively inhibits the binding of interleukin-1 to the type II interleukin-1 receptor.

The interleukin-1 receptor antagonist (IL-1ra) inhibits the binding of interleukin-1 (IL-1) to T-cell lines possessing the type I IL-1 receptor; evidence has been published (Carter, D. B., Deibel, M. R. J., Dunn, C. J., Tomich, C. S., Laborde, A. L., Slightom, J. L., Berger, A. E., Bienkowski, M. J., Sun, F. F., McEwan, R. N., Harris, P. K. W., Yem, A. W., Waszak, G. A., Chosay, J. G., Sieu, L. C., Hardee, M. M., Zurcher-Neely, H. A., Reardon, I. M., Heinrickson, R. L., Truesdell, S. E., Shelly, J. A., Eessalu, T. E., Taylor, B. M., and Tracey, D. E. (1990) Nature 344, 633-638; Hannum, C. H., Wilcox, C. J., Arend, W. P., Joslin, F. G., Dripps, D. J., Heimdal, P. L., Armes, L. G., Sommer, A., Eisenberg, S. P., and Thompson, R. C. (1990) Nature 343, 336-340) that IL-Ira does not bind to the type II IL-1 receptor (IL-1RtII). In this study we examined the ability of human recombinant IL-1ra to block the binding of IL-1 to the IL-1RtII on human polymorphonuclear leukocytes (PMN) and Raji human B-lymphoma cells. The binding of 125I-IL-1 beta to PMN was competively inhibited by IL-1ra. IL-1 beta was more potent in inhibiting the binding of 125I-IL-1 beta than IL-1ra. Incubating PMN with 125I-IL-1ra in the presence of increasing concentrations of IL-1 beta or IL-1ra showed that IL-1 beta was an approximately 40-fold more potent inhibitor of binding of 125I-IL-1ra than unlabeled IL-1ra. The IL-1ra was approximately 500-fold less potent in inhibiting the binding of 125I-IL-1 alpha than IL-1 alpha. IL-1ra was also able to competitively inhibit binding of 125I-IL-1 beta to Raji cells. PMN or Raji cells were also incubated with 125I-IL-1 in the absence or presence of IL-1 or IL-1ra. After cross-linking of IL-1 to cells followed by specific immunoprecipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a band at 85 kDa corresponding to the 68-kDa IL-1RtII. However, in the presence of an excess of either unlabeled IL-1 or IL-1ra, the 85-kDa IL-1.IL-1RtII complex was not present. These findings demonstrate that the IL-1ra recognizes and blocks IL-1 binding to the IL-1RtII.

Binding, Competitive↗