Showing papers by "Charles A. Dinarello published in 1996"

Effect of endotoxin in IL-1 beta-deficient mice.

Abstract: IL-1 plays an important role in the pathophysiologic responses to infection and inflammation, in part by mediating its own production and that of other proinflammatory cytokines. However, the relative contribution of IL-1 alpha and IL-1 beta to the inflammatory response has not been well clarified. Using IL-1 beta-deficient (IL-1 beta -/-) mice, we investigated the specific role of IL-1 beta in the in vivo and in vitro response to LPS. No differences between IL-1 beta +/+ and IL-1 beta -/- mice were observed in circulating levels for IL-1 alpha, IL-6, or TNF-alpha after the systemic administration of either a low (5 micrograms/kg) or high (5 mg/kg) dose of LPS. IL-1 beta -/- mice also had a normal response to LPS in terms of activation of the hypothalamus-pituitary-adrenal axis, hypoglycemia, serum amyloid A production, and anorexia. IL-1 beta -/- mice were normally sensitive to the lethal effect of LPS and were protected against LPS toxicity when pretreated with low-dose LPS. However, in vitro, peritoneal macrophages from IL-1 beta -/- mice stimulated with LPS produced significantly less IL-1 alpha than macrophages from IL-1 beta +/+ mice (p < 0.05). No differences in IL-6 or TNF-alpha synthesis were observed between macrophages from IL-1 beta +/+ and IL-1 beta -/- mice. In summary, our results suggest that either IL-1 beta is not essential for the in vivo systemic response to LPS or that its role can be fulfilled by other cytokines with overlapping activities.

A new biologic role for C3a and C3a desArg: regulation of TNF-alpha and IL-1 beta synthesis.

Abstract: The complement activation products C3a and C3a desArg are generated in the course of trauma, infection, tissue injury, and ischemia We have investigated the effects of C3a and C3a desArg on gene expression and protein synthesis of TNF-alpha and IL-1 beta in PBMC Neither C3a nor C3a desArg alone induced detectable protein or mRNA levels for TNF-alpha and IL-1 beta C3a modulated LPS-induced TNF-alpha and IL-1 beta synthesis In nonadherent PBMC, C3a suppressed LPS-induced synthesis of TNF-alpha (20-71% decrease by 02-10 microgram/ml of C3a, p less than 001) and IL-1 beta (19-57% decrease by 05-10 microgram/ml of C3a, p less than 001), independently of endogenous production of PGE2 C3a also suppressed LPS-induced mRNA levels for TNF-alpha and IL-1 beta In contrast, in adherent PBMC, C3a at 5 to 20 microgram/ml enhanced LPS-induced TNF-alpha (75-188% increase, p less than 0001) and IL-1 beta (119-274% increase, p less than 0001) synthesis C3a enhanced TNF-alpha and IL-1 beta mRNA levels in LPS-stimulated adherent cells Furthermore, C3a desArg shared with C3a the ability to modulate LPS-induced mRNA and protein synthesis for TNF-alpha and IL-1 beta These results suggest that C3a, thought to be proinflammatory, and C3a desArg, thought to be biologically inactive, are modulators of inflammation Both C3a and C3a desArg may enhance cytokine synthesis by adherent monocytes at local inflammatory sites, while inhibiting the systemic synthesis of proinflammatory cytokines by circulating cells

Cytokines as mediators in the pathogenesis of septic shock.

Abstract: During septic shock the host produces several proinflammatory cytokines which have been implicated as playing a critical role in the pathogenesis of the disease. The production of these cytokines is initiated by the organisms themselves (phagocytosis) or by soluble products of the organisms. For example, the lipopolysaccharide endotoxins (LPS) of gram-negative bacteria, the protein exotoxins of gram-positive bacteria, and the cell-wall glycopeptides such as teichoic acids and muramyl peptides. Of course, LPS is by far the most potent soluble product of bacteria which induces cytokine production, and therefore most information about cytokine induction is derived from studies using LPS in vitro and in vivo. However, it is important to recognize that the cytokine production in septic shock is neither specific nor unique. The cytokines which contribute to pathological changes in septic shock are not unique to infection. Multiple trauma, ischemia-reperfusion injury, acute transplant rejection, antigen-specific immune responses, and various acute inflammatory states (acute hepatitis and pancreatitis) initiate the same cytokine cascade and result in both systemic and local inflammatory processes.

The inflammatory response in interleukin-1 beta-deficient mice: comparison with other cytokine-related knock-out mice.

Abstract: Interleukin-1 (IL-1) plays a crucial role in the development of the pathophysiological responses to infection and inflammation. However, the relative contributions of IL-1 alpha and IL-1 beta remain to be clarified. IL-1 beta-deficient mice are a powerful tool to investigate the specific role of IL-1 beta in various experimental conditions. In this report, we summarize the response of IL-1 beta deficient mice to two different inflammatory stimuli, turpentine and endotoxin. Although IL-1 beta-deficient mice respond normally to the systemic administration of lipopolysaccharide (LPS), they do not develop an acute-phase response in the localized tissue damage model of turpentine injection. The results obtained using the IL-1 beta-deficient mice are compared here with those observed in the IL-1 beta-converting enzyme-deficient, IL-6-deficient, tumour necrosis factor-receptor p55-deficient, and interferon-gamma-receptor-deficient mice.

Protein metabolism in rheumatoid arthritis and aging. Effects of muscle strength training and tumor necrosis factor α

Abstract: OBJECTIVE To determine the effects of rheumatoid arthritis (RA) on whole-body protein metabolism. METHODS We examined protein metabolism and its hormonal and cytokine mediators before and 12 weeks after progressive resistance muscle strength training in 8 healthy young (mean +/- SD age 25 +/- 2 years) and 8 healthy elderly (70 +/- 5 years) men and women, and in 8 adults with RA (42 +/- 13 years). An additional 6 healthy elderly subjects (69 +/- 3 years) served as a swimming-only control group. RESULTS Subjects with RA had higher rates of protein breakdown than did young or elderly healthy subjects (79.9 +/- 17.2 versus 60.3 +/- 5.8 and 63.7 +/- 12.4 mumoles/gm total body potassium/hour, respectively, P < 0.05), while there was no effect of age per se. Patients treated with methotrexate had normal rates of protein breakdown (P < 0.01 versus RA without methotrexate; P not significant versus healthy young subjects). Increased protein catabolism in RA was no longer evident after strength training. In multiple regression analysis, levels of tumor necrosis factor alpha (TNF alpha) (r = 0.47, P = 0.01) and growth hormone (r = -0.51, P = 0.006) were associated with protein breakdown, and plasma glucagon levels were inversely correlated with protein synthesis (r = -0.45, P = 0.02). Growth hormone (r = -0.56, P = 0.002) and glucagon (r = 0.45, P = 0.04, levels were associated with protein oxidation. CONCLUSION Adults with RA have increased whole-body protein breakdown, which correlates with growth hormone, glucagon, and TNF alpha production.

Interleukin 1 (IL-1)-dependent melanoma hepatic metastasis in vivo; increased endothelial adherence by IL-1-induced mannose receptors and growth factor production in vitro

Abstract: Background : The growth of cancer cells in inflammatory tissue is often observed. This can be the result of favorable conditions for endothelial cell adherence and/or increased production of local growth factors. Purpose : The role of the proinflammatory cytokine interleukin 1 (IL-1) in the prometastatic and growth-promoting environment of inflammation was studied in vivo, and the mechanism of cytokine action was studied in vitro as well. Methods : Systemic inflammation was induced by the intravenous injection of IL-1β or lipopolysaccharide (LPS), and the hepatic metastasizing ability of B16 melanoma (B16) cells following intrasplenic injection was studied. IL-1 receptor blockade was accomplished with the use of the IL-1 receptor antagonist (IL-1Ra). In vitro, IL-1Ra was used to assess the mechanism for prometastasis and growth promotion of cultured hepatic sinusoidal endothelium stimulated with LPS. Results : There was a statistically significant (P<.01) enhancement in the parameters of hepatic metastasis when B16 cells were injected intrasplenically either 4 hours after IL-1 injection or 6 or 12 hours after LPS injection. IL-1Ra pretreatment reduced IL-1-induced enhancement of metastasis by 73%-87% and completely inhibited the augmentation of metastasis following LPS injection. In vitro, the adherence of melanoma cells to LPS-treated endothelium increased nearly twofold but was completely abrogated when IL-1Ra was added before LPS. Similar to melanoma adherence, a 2.5-fold increase (P<.05) in functional mannose receptors was observed with LPS treatment but was prevented by the addition of IL-1Ra. IL-1Ra did not affect basal mannose-receptor activity in unstimulated epithelium. Mannose-receptor activity and B16 cell adherence significantly correlated (r =.9) with LPS treatment. Conditioned medium from LPS-stimulated epithelium augmented B16 cell proliferation compared with control conditioned medium (P<.01). Production of B16 cell growth factor(s) was markedly reduced (P<.01) when IL-1Ra was added. Conclusions : These results demonstrate that systemic inflammation induces an enhancement of melanoma cell metastasis and growth by IL-1-dependent mechanisms in vivo. In vitro, the mechanism(s) is consistent with IL-1-mediated increase in expression of mannose receptors and production of tumor cell growth factor(s) from the endothelium. Implications : Given the multiple and complex cytokine cascade induced in vivo and in vitro during LPS-induced systemic inflammation, IL-1 plays a strategic role. Since IL-1Ra is without side effects in humans, studies on intraoperative infusion of IL-1Ra during tumor resection may be indicated.

Clinical, hematologic, and immunologic effects of interleukin-10 in humans.

Abstract: We conducted a double-blind, placebo-controlled study to investigate the safety, pharmacokinetics, and immunological properties of interleukin-10 (IL-10) administration in healthy humans. Volunteers received a single intravenous bolus injection of recombinant human IL-10 (1, 10, or 25μg/kg) or placebo. Cytokine production in whole blood and peripheral blood mononuclear cells (PBMC) was assessed before and 3, 6, 24, and 48 hr after the injection. Peak serum concentrations of IL-10 (15±1.1, 208±20.1, and 505±22.3 ng/ml) occurred after 2–5 min for 1, 10, and 25μg/kg IL-10, respectively. The terminal-phase half-life was 3.18 hr. A transient leukocytosis (24–63% above baseline) was observed 6 hr after injection, which coincided with a dose-dependent decrease (12–24%) in neutrophil superoxide generation. There was a marked inhibition (60–95%) of endotoxin-induced IL-6 production from whole blood in each group receiving IL-10. Production of IL-8 in endotoxin-stimulated blood was reduced in the 10μg/kg group. In PBMC stimulated with phytohemagglutinin and phorbol ester, there was a decrease (72–87%) in interferon-γ (IFNγ) production 6 hr after IL-10 with a return to pre-IL-10 levels after 24 hr. This reduction was only partially associated with a decrease in the number of CD2-bearing cells. We conclude that IL-10 administration into humans is without significant side effects, and a single injection reducesex vivo production of IL-6, IL-8, and IFNγ.

Plasma Cytokines, Cytokine Antagonists, and Disease Progression in African Women Infected with HIV-1

Abstract: Objectives: To examine the relation of circulating cytokines and cytokine antagonists to the progression of human immunodeficiency virus type 1 (HIV-1) disease. Design: Cross-sectional analysis. Se...

Oral aspirin and ibuprofen increase cytokine-induced synthesis of IL-1β and of tumour necrosis factor-αex vivo

Abstract: We investigated the effect of oral aspirin and ibuprofen on the ex vivo synthesis of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) by stimulated peripheral blood mononuclear cells (PBMC) from healthy volunteers. Seven volunteers took 325 mg of aspirin daily for 14 days. Three weeks after ending aspirin medication, ex vivo IL-1 beta and TNF synthesis induced by exogenous IL-1 alpha was elevated threefold compared to the pre-aspirin value (P = 0.01 and P = 0.005, respectively). Using lipopolysaccharide (LPS) as a stimulus, no influence of oral aspirin was observed. The increase in cytokine synthesis did not parallel decreased synthesis of prostaglandin E2 (PGE2). Seven weeks after discontinuation of aspirin, cytokine and PGE-2 production returned to pre-aspirin levels. Another seven volunteers took 200 mg of ibuprofen daily for 12 days. Again, there was no effect on LPS- or Staphylococcus epidermidis-induced cytokine synthesis. However, IL-1 alpha-induced synthesis of IL-1 beta was elevated to a mean individual increase of 538% (P < 0.001) and synthesis of TNF was elevated to 270% (P < 0.001) at the end of ibuprofen medication and 2 weeks after discontinuation of ibuprofen. There were parallel increases in PGE2 and both returned to their pre-ibuprofen levels 5 weeks after stopping. Although inhibitors of cyclo-oxygenase blunt PGE2-mediated symptoms such as fever and pain, we conclude that short term use of either aspirin or ibuprofen results in a 'rebound' increase in cytokine-induced cytokine synthesis that is not observed in LPS-induced cytokines.

Mechanisms of loss of lean body mass in patients on chronic dialysis.

Abstract: Patients on chronic dialysis treatment often have reduced lean body mass. Certain aspects of bio-incompatibility in dialysis can be viewed as leading to a chronic inflammatory state. In most chronic inflammatory diseases, loss of mean body mass is independent of reduced caloric intake. However, reduced caloric intake accounts for most of the weight loss in these patients and also dialysis patients. Refeeding is associated with increased fat deposition more than restoration of muscle mass. In addition to reduced caloric intake, patients with rheumatoid arthritis, a classic example of a chronic inflammatory disease, have an elevated resting energy expenditure associated with decreased lean body mass. Elevated cellular tumor necrosis factor (TNF) and IL-1 beta production can be demonstrated in these patients. However, in many dialysis patients, increased cytokine production can be 'normal' or reduced. This takes place as the level of malnutrition increases. Thus, cytokines such as IL-1 and TNF play a decreasing role in the pathogenesis of loss of body mass as malnutrition increases and curtails the synthesis of cytokines. Similar to patients with AIDS, progressive disease in patients on chronic dialysis may exhibit subclinical malnutrition which leads to decreased cytokine production. Reduction in cytokine production can be viewed as a protective mechanism.

Phase I trial of interleukin 2 in combination with the soluble tumor necrosis factor receptor p75 IgG chimera.

Abstract: Our purpose was to determine the effective biological dose and/or maximum tolerated dose of recombinant human tumor necrosis factor receptor:IgG chimera (rhuTNFR:Fc; Immunex, Seattle, WA) in combination with interleukin 2 (IL-2) with regard to reduction in IL-2 toxicity and modulation of biological effects of high-dose IL-2 administration. Twenty-four patients with metastatic cancer were treated with escalating doses of rhuTNFR:Fc at 1, 1, 5, 10, and 20 mg/m2 i.v. on days 1 and 15 (dose levels 1-5) or 10, 20, and 30 mg/m2 days 1 and 15 plus 50% dose on days 3, 5, 17, and 19 (dose levels 6-8) prior to IL-2 at doses of 300,000 IU/kg (dose level 1) and 600,000 IU/kg (dose levels 2-8) i.v. every 8 h on days 1-5 and 15-19. The t1/2 of rhuTNFR in patients receiving IL-2 was 72 h. The median number of IL-2 doses was 24, and central nervous system, skin, and cardiac arrhythmias were the major dose-limiting toxicities. TNF bioactivity was inhibited, and the polymorphonuclear leukocyte chemotactic defect normally seen with IL-2 was not observed. Increases in C-reactive protein, IL-6, IL-8, and IL-1 receptor antagonist levels were partially suppressed relative to historical controls, whereas peripheral blood mononuclear cell phenotypes, urinary nitrate, endothelial adhesion molecule expression in skin biopsies, and cellular infiltrates in tumor biopsies were consistent with findings in patients treated with IL-2 alone. Four patients developed thyroid dysfunction. There were five responses: two complete responses (both melanoma) and three partial responses (response rate, 21%). rhuTNFR:Fc may modulate the toxicity and some of the biological effects of IL-2 while preserving antitumor activity. Dose level 6 (10 mg/m2 on days 1 and 15, and 5 mg/m2 on days 3, 5, 17, and 19) has been chosen for a randomized, double-blind, placebo-controlled trial of IL-2 with and without rhuTNFR:Fc.

Transfer of cytokine-inducing bacterial products across hemodialyzer membranes in the presence of plasma or whole blood.

Abstract: Cytokine production by peripheral blood mononuclear cells (PBMC) is a sensitive indicator of cytokine-inducing substances which may cross from contaminated dialysate into the blood compartment. The objective of this study was to compare the transfer of cytokine-inducing substances from dialysate contaminated with a culture filtrate from Pseudomonas aeruginosa across dialyzers with low (hemophan) or intermediate ultrafiltration coefficients (modified cellulose triacetate, CTA), under conditions where either 10% plasma or whole blood was circulated in the blood compartment. Eight paired experiments of in vitro dialysis were carried out at 37 degrees C using a countercurrent recirculating loop dialysis circuit with either a new CTA or hemophan dialyzer. 10% plasma in standard tissue culture medium was circulated through the blood compartment and bicarbonate dialysate was circulated in the dialysate compartment. The dialysate was challenged sequentially by log-fold dilutions (10(2), 10(3) or 10(4)) of a Ps. aeruginosa culture filtrate. Samples were drawn from the blood compartment 5 and 15 minutes after each challenge and incubated with suspensions of PBMC in the absence or presence of polymyxin B, in order to block endotoxin. After 24 h at 37 degrees C, total interleukin-1 alpha (IL-1 alpha) was measured by RIA. Although the dialysate contained potent cytokine-inducing substances, there was no significant IL-1 alpha production by PBMC incubated with the plasma mixture from the blood compartment in the majority of experiments with both dialyzers and with each of the three dilutions of the bacterial challenge. Eight experiments were also performed with CTA dialzyers using heparinized whole blood in the blood compartment. Samples of whole blood and dialysate were drawn at baseline, after one hour of dialysis with uncontaminated dialysate and 15 minutes and three hours after dialysis with dialysate contaminated with Ps. aeruginosa filtrate. There was no significant IL-1 alpha production by PBMC isolated from the whole blood 1 h after dialysis with uncontaminated dialysate, and 15 min and 2 h after adding the Ps. aeruginosa filtrate to the dialysate side. In contrast, production of IL-1 alpha by PBMC from the same donors incubated with samples from the dialysate were 263 +/- 50, 1074 +/- 306, 2333 +/- 774 and 2602 +/- 702 pg/2.5 x 10(6) PBMC, respectively at the same four time points. These data suggest that although the Ps. aeruginosa culture filtrate present in the dialysate was a potent inducer of IL-1 alpha, neither dialyzer permitted transfer of cytokine inducing substances from the dialysate into the blood compartment.

Synthesis of tumor necrosis factor alpha and interleukin-1 receptor antagonist, but not interleukin-1, by human mononuclear cells is enhanced by exposure of whole blood to shear stress.

Abstract: Extracorporeal circulation exposes blood to shear stress. In many studies, researchers reported effects of shear stress on morphology and function of various blood cells, but effects on cytokine synthesis have not been studied. The authors investigated the effect of shear stress on the synthesis of interleukin-1 beta, interleukin-1 alpha, tumor necrosis factor alpha, and interleukin-1 receptor antagonist by human peripheral blood mononuclear cells. Whole heparinized blood at room temperature was exposed to shear stresses of 50, 200, or 500 dyne/cm2 for 5 min or 30 sec, and to 980 dyne/cm2 for 5 sec. Peripheral blood mononuclear cells were then separated from sheared blood and cultured for 24 hrs with or without lipopolysaccharide or Staphylococcus epidermidis. Total (intra + extracellular) cytokine synthesis was measured by specific radioimmunoassay. Viability of cultured peripheral blood mononuclear cells, determined by trypan blue exclusion and lactate dehydrogenase release, was not significantly affected by shear stress. Shear stress without lipopolysaccharide or S. epidermidis stimulation did not affect synthesis of interleukin-1 or tumor necrosis factor alpha but did enhance synthesis of interleukin-1 receptor antagonist. Lipopolysaccharide- or S. epidermidis- induced synthesis of interleukin-1 was not significantly altered by shear stress. In contrast, lipopolysaccharide-induced tumor necrosis factor alpha synthesis increased with increasing shear stress and was significantly elevated over unsheared controls, whereas S. epidermidis-induced tumor necrosis factor alpha and lipopolysaccharide- or S. epidermidis-induced interleukin-1 receptor antagonist synthesis were not significantly enhanced by shear. Therefore, sublytic trauma, such as exposure to shear stress, affects in vitro responses of peripheral blood mononuclear cells to secondary stimuli.

An antibody to a 17 amino acid synthetic peptide of the type I interleukin-1 receptor preferentially blocks interleukin-1 beta binding.

Abstract: On the basis of their relative hydropathy and α-helical structure, we prepared antibodies to four synthetic peptides with amino acid sequences homologous to four hydrophilic, extracellular regions of the murine 80 kDa type I interleukin-1 receptor (IL-1RI). Antibodies to each of the four peptides recognized their specific immunogen. Human [125I]-IL-lα or -β was crosslinked to murine EL4 and D10S cells. Antiserum to peptide 150-166 precipitated the IL-1/IL-1R complex, whereas antibodies to peptide 66-84, 190-200, or 266-285 did not. Antibody to peptide 150-166 did not precipitate the type II IL-1R. Anti-IL-1RI150-166 blocked 71% of the binding of radiolabeled human IL-1β to EL4 cells and 50% of the binding to D10S cells. Using affinity-purified anti-IL-1RI150-166, we compared the ability of this antibody to inhibit the binding of murine or human IL-1α to that of murine or human IL-1β. At a concentration of 20 ng/ml, affinity-purified anti-IL-1RI150-166 blocked 50% binding of murine IL-1β. At 1 μg/ml, 90% b...

Soluble tumor necrosis factor receptors inhibit phorbol myristate acetate and cytokine-induced HIV-1 expression chronically infected U1 cells.

Abstract: Recombinant human tumor necrosis factor (TNF) binding protein-1 (r-h TBP-1) and recombinant human soluble dimeric TNF receptor (rhu TNFR:Fc) were used to determine the relative contributions of TNF to phorbol myristate acetate (PMA) and cytokine-induced human immunodeficiency virus type 1 (HIV-1) replication in chronically infected cell lines. Treatment of HIV-1-infected promonocytic U1 cells with r-h-TBP-1 or rhu TNFR:Fc reduced PMA-induced HIV-1 p24 antigen production in a concentration-dependent manner, with a maximal inhibition of approximately 90%. Maximal inhibition of p24 antigen production in T-lymphocytic ACH-2 cells was 47% with r-hTBP-1 and 42% with rhu TNFR:Fc. r-hTBP-1 and rhu TNFR:Fc also decreased p24 antigen synthesized by U1 cells in response to other stimuli, including phytohemagglutinin (PHA)-induced supernatant, granulocyte-macrophage colony-stimulating factor, interleukin-6, and TNF. Addition of r-hTBP-1 to U1 cells during the last 4 h of a 24 h incubation with PMA still inhibited p24 antigen production by 15%. U1 cells stimulated with 10(-7) M PMA released approximately 1 ng/ml endogenous TBP-1 with an initial peak observed at 1 h and a second peak at 24 h after PMA stimulation. r-hTBP-1 also partially reversed inhibition of U1 cellular proliferation caused by PMA. Both r-hTBP-1 and rhu TNFR:Fc blocked PMA induction of nuclear factor (NK)- kappa B DNA-binding activity in U1 cells in association with decreases in HIV-1 replication. We conclude that soluble TNF receptors can inhibit stimuli-induced HIV-1 expression and NK- kappa B DNA-binding activity in chronically infected U1 cells.

Effects of Muscle Strength Training and Tumor Necrosis Factor a

Abstract: Objective. To determine the effects of rheumatoid arthritis (RA) on whole-body protein metabolism. Methods. We examined protein metabolism and its hormonal and cytokine mediators before and 12 weeks after progressive resistance muscle strength training in 8 healthy young (mean k SD age 25 2 2 years) and 8 healthy elderly (70 rt 5 years) men and women, and in 8 adults with RA (42 2 13 years). An additional 6 healthy elderly subjects (69 k 3 years) served as a swimming-only control group. Results. Subjects with RA had higher rates of protein breakdown than did young or elderly healthy subjects (79.9 f 17.2 versus 60.3 f 5.8 and 63.7 2 12.4 pmoles/gm total body potassium/hour, respectively, P < 0.05), while there was no effect of age per se. Patients treated with methotrexate had normal rates of protein breakdown (P < 0.01 versus RA without methotrexate; P not significant versus healthy young subjects). Increased protein catabolism in RA was no longer evident