Determination of IL1 alpha, IL1 beta and IL2 in biological media using specific enzyme immunometric assays

Ameliorative effects of ribes rubrum oil against gastric ulcers caused by indomethacin in experimental models

The objective of this study was to assess the anti-inflammatory effects of ribes rubrum oil at three different doses (5, 10 and 15 ml/kg b.w/day) in adult male albino rats with indomethacin-induced stomach ulcers (IND). Forty rats (135 ± 5 g) categorized into 5 groups (n = 8), for 45 days. Group (1) normal control, thirty-two rats were gavaged IND as single oral dose (30 mg/Kg b.w) resulted in gastric ulcer, then distributed to four groups, group (2) IND-intoxicated control, Groups 3, 4 and 5 were administrated ribes rubrum oil at levels of (5, 10 & 15 ml/kg b.w) respectively. Administrated levels of ribes rubrum oil found to have remarkable elevation in food conversion efficiency in experimental rats, gastric juice pH, in compared to the drunken control group, gastric prostaglandin E2 and gastric cytochrome P450 reductase levels were lower. The levels of pro-inflammatory cytokines NO, TNF-, and IL-1 were dramatically reduced, which was related with an increase in blood hemoglobin (Hb), packed cell volume (PCV), and red blood cells (RBCs)in ulcerogenic rats compared to intoxicated control. Data showed that, the main components of ribes rubrum oil are β-Pinene, γ-linolenic and Linalool oxide levels (25.9%, 23.10% and 10.5%, respectively) for their antioxidant activity. Findings showed that administrate ribes rubrum oil at dose 15 ml/kg followed by 10 ml/kg had the best results against ulcerogenic rats. In conclusion, the outcomes are consistent with the concept that ribes rubrum oil had a gastroprotective and antisecretory effects against gastric ulcer that may be attributed to the antioxidant properties of the oil that ameliorates the damage occur in gastric of rats.

The protective efficacy of vitamin E and cod liver oil against cisplatin-induced acute kidney injury in rats

Cisplatin (CP) is a highly effective chemotherapeutic agent against neoplasms, but its clinical utility is limited due to the side effects of its dose-dependent nephrotoxicity. Vitamin E (Vit E) and cod liver oil (CLO) are natural substances with chemoprotective effects. The present study was conducted to evaluate the protective effects of Vit E and/or CLO for CP-induced acute kidney injury (AKI) in rats. This study involved 40 mature male Wistar albino rats that were equally allocated into eight groups: Veh, Vit E, CLO, Vit E + CLO, CP, Vit E + CP, CLO + CP, and Vit E + CLO + CP. The co-administration of Vit E and CLO significantly ameliorated CP-induced elevations in serum creatinine (Cr), blood urea nitrogen (BUN), interleukin 1 beta (IL-1β), and interleukin- 6 (IL-6). Further, rats that received Vit E and/or CLO showed significant decrease in malondialdehyde (MDA) and increases in superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels in renal tissues, compared to CP-intoxicated rats. Additionally, the treatment restored the normal histological architecture (except for few cast formations) and upregulated the immunostaining area% of aquaporin 3 (AQP3) and downregulated the immunostaining area% of Bcl2 associated X protein (BAX) and inducible nitric oxide synthase (iNOS). The observed effects were stronger in the combination treatment group. The obtained data revealed that Vit E and CLO co-administration protects against the CP-induced AKI more than monotherapy with Vit E or CLO.

Abd-Elhakim Y. Saussurea lappa Ethanolic Extract Attenuates Triamcinolone Acetonide-Induced Pulmonary and Splenic Tissue Damage in Rats via Modulation of Oxidative Stress, Inflammation, and Apoptosis

Background: In this era, worldwide interest has been directed towards using natural antioxidants to guard against drug side effects. Saussurea lappa is a famous medicinal plant with many biologically active compounds. Triamcinolone acetonide (TA) is an extensively used glucocorticoid. Hence, this study explored, for the first time, the possible beneficial effects of S. lappa ethanolic extract on TA-induced oxidative damage in the lung and spleen of rats. Methods: Five experimental groups were used: control group, S. lappa-treated group (600 mg/kg/day, orally), TA-treated group (40 mg/kg/twice/week I/P), S. lappa + TA co-treated group, and S. lappa/TA prophylactic group. Results: TA exposure significantly induced leukocytosis and neutrophilia. In addition, TA significantly reduced the levels of C-reactive protein, interleukin-12, tumor necrosis factor α, and immunoglobulins. Lung Caspase-3 overexpression and splenic CD8⁺ downregulation were also noted in the TA group. TA treatment significantly increased malondialdehyde concentration but reduced superoxide dismutase and glutathione peroxidase activities. S. lappa counteracted the TA oxidative and apoptotic effects. The best results were recorded in the prophylactic group. Conclusions:S. lappa has a remarkable protective effect via its anti-inflammatory, anti-apoptotic, and antioxidant capacity. Thus, it could be a candidate as a natural antioxidant to face glucocorticoid’s harmful side effects.

The evaluation of cytokines to help establish diagnosis and guide treatment of autoinflammatory and autoimmune diseases

Our knowledge of the role of cytokines in pathologic conditions has increased considerably with the emergence of molecular and genetic studies, particularly in the case of autoinflammatory monogenic diseases. Many rare disorders, considered orphan until recently, are directly related to abnormal gene regulation, and the treatment with biologic agents (biologics) targeting cytokine receptors, intracellular signaling or specific cytokines improve the symptoms of an increasing number of chronic inflammatory diseases. As it is currently impossible to systematically conduct genetic studies for all patients with autoinflammatory and autoimmune diseases, the evaluation of cytokines can be seen as a simple, less time consuming, and less expensive alternative. This approach could be especially useful when the diagnosis of syndromes of diseases of unknown etiology remains problematic. The evaluation of cytokines could also help avoid the current trial-and-error approach, which has the disadvantages of exposing patients to ineffective drugs with possible unnecessary side effects and permanent organ damages. In this review, we discuss the various possibilities, as well as the limitations of evaluating the cytokine profiles of patients suffering from autoinflammatory and autoimmune diseases, with methods such as direct detection of cytokines in the plasma/serum or following ex vivo stimulation of PBMCs leading to the production of their cytokine secretome. The patients' secretome, combined with biomarkers ranging from genetic and epigenetic analyses to immunologic biomarkers, may help not only the diagnosis but also guide the choice of biologics for more efficient and rapid treatments.

Mast cells and pro-inflammatory cytokines roles in assessment of grape seeds extract anti-inflammatory activity in rat model of carrageenan-induced paw edema

OBJECTIVES

Reactive oxygen species (ROS)-produced oxidative disorders were involved at the pathophysiology of many inflammatory processes via the generation of pro-inflammatory cytokines and antioxidant defense system suppression. Although herbal antioxidants as mono-therapy relief many inflammatory diseases including, autoimmunity rheumatoid arthritis, but as combination therapy with other proven anti-inflammatory drugs in order to decreasing their toxic impacts has not yet been studied clearly, especially against chemical substances that's induced local inflammation with characteristic edema.

MATERIALS AND METHODS

Grape seeds extract (GSE) at a concentration of 40 mg/kg B. wt alone or in combination with indomethacin (Indo.) at a dose of 5 mg/Kg B. wt orally given for 10 days prior (gps VI, VII, VIII) or as a single dose after edema induction (gps IX, X, XI) in rat's left hind paw by sub-planter single injection of 0.1 carrageenan: saline solution (1%) (gp. V) to assess the prophylactic and therapeutic anti-inflammatory activities of both through the estimation of selective inflammatory mediators and oxidative damage-related biomarkers as well as tissue mast cell scoring. Furthermore, both substances were given alone (gps II, III, IV) for their blood, liver and kidney safety evaluation comparing with negative control rats (gp. I) which kept without medication.

RESULTS

A marked reduction on the inflammatory mediators, edema volume and oxidative byproducts in edema bearing rats' prophylactic and treated with grape seeds extract and indomethacin was observed. Indomethacin found to induce some toxicological impacts which minimized when administered together with GSE.

CONCLUSION

GSE is a safe antioxidant agent with anti-inflammatory property.

Sensitivity of PEGylated interferon detection by anti-polyethylene glycol (PEG) antibodies depends on PEG length

Attachment of poly(ethylene glycol) to proteins can mask immune epitopes to increase serum half-life, reduce immunogenicity, and enhance in vivo biological efficacy. However, PEGylation mediated epitope-masking may also limit sensitivity and accuracy of traditional ELISA. We previously described an anti-PEG-based sandwich ELISA for universal assay of PEGylated molecules. Here, we compared the quantitative assessment of PEGylated interferons by anti-PEG and traditional anti-interferon sandwich ELISA. The detection limits for PEG-Intron (12k-PEG) and Pegasys (40k-PEG) were 1.9 and 0.03 ng/mL for anti-PEG ELISA compared to 0.18 and 0.42 ng/mL for traditional anti-interferon sandwich ELISA. These results indicate that the anti-PEG sandwich ELISA was insensitive to PEGylation mediated epitope-masking and the sensitivity increased in proportion to the length of PEG. By contrast, PEG-masking interfered with detection by traditional anti-interferon sandwich ELISA. Human and mouse serum did not affect the sensitivity of anti-PEG ELISA but impeded traditional anti-interferon sandwich ELISA. The anti-PEG sandwich ELISA was comparable to anti-interferon sandwich ELISA and radioassay of 131I-Pegasys in pharmacokinetic studies in mice. The anti-PEG sandwich ELISA provides a sensitive, accurate, and convenient quantitative measurement of PEGylated protein drugs.

Normal human primary CD4+ T lymphocytes synthesize and release functional osteoprotegerin in vitro

Osteoprotegerin (OPG) acts as a decoy receptor for receptor activator of nuclear factor-kappaB ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). OPG regulates bone remodeling and the immune response. The primary objective was to decipher, among human peripheral blood mononuclear leukocytes (PBML) that produce OPG, the subset(s) responsible for this synthesis and its regulation. To this end, normal human PBML and CD4-, 8-, 19-, 14-enriched subpopulations were studied in vitro for OPG synthesis. PBML were subjected to adherence and immunomagnetic separation, and OPG expression was analyzed by PCR, northern and western blotting, and ELISA. The antiapoptotic effects of OPG were studied on TRAIL-stimulated RPMI 8226 myeloma cells. OPG was time-dependently produced by primary CD4+ T lymphocytes exclusively. OPG secretion was upregulated by anti-CD3 antibody stimulation or incubation with interleukin (IL)-4, IL-1beta, TNF-alpha, GM-CSF, and vitamin D(3). In contrast, IL-10 inhibited the basal and IL-4-induced production of OPG by T cells. Conditioned media from activated T lymphocytes decreased TRAIL-induced apoptosis of RPMI 8226 cells. This effect was reversed by addition of RANKL to the T-cell conditioned media. As human immunodeficiency virus-1 (HIV-1) targets CD4+ T cells, we evaluated the effects of recombinant HIV-1 gp120 proteins on OPG synthesis. The gp120 from three different HIV-1 strains significantly reduced the basal output of OPG from T cells. Furthermore, all four protease inhibitors (PIs) used in highly active antiretroviral therapy decreased OPG synthesis by human blood T cells, nelfinavir being the most efficient PI. The simultaneous presence of an HIV-1 gp120 and a PI abrogated the basal output of OPG. In conclusion, these results highlight a new role for T lymphocytes involved in pathologies. Activated CD4+ T cells could, through OPG release, have a paracrine effect on adjacent cells and contribute to reduce the local process of bone remodeling and cellular apoptosis.

Influence of lycopene and vitamin C from tomato juice on biomarkers of oxidative stress and inflammation

A human study was carried out to investigate whether tomato juice, rich in natural lycopene and fortified with vitamin C, is able to reduce several biomarkers of oxidative stress and inflammation and whether the effect can be attributed to lycopene, vitamin C or any other micronutrient. Following a 2-week depletion phase, volunteers were assigned randomly to ingest either tomato juice with (LC) or without (L) vitamin C fortification for 2 weeks (daily dose 20·6 mg lycopene and 45·5/435 mg vitamin C). Plasma and urine were analysed for carotenoids and vitamin C, lipid status, antioxidant capacity, thiobarbituric acid reactive substances (TBARS) and 8-epi-PGF2α, protein carbonyls, cytokines IL-1β and TNFα and C-reactive protein (CRP). The consumption of tomato juice led to a reduction in total cholesterol levels (L: 157·6v. 153·2 mg/dl,P = 0·008; LC: 153·4v. 147·4 mg/dl,P = 0·002) and that of CRP (L: 315·6v. 262·3 μg/l,P = 0·017; LC: 319·2v. 247·1 μg/l,P = 0·001) in both groups. The vitamin C-fortified juice slightly raised the antioxidant capacity in urine and decreased TBARS in plasma and urine. All other markers were affected to a lesser extent or remained unchanged. Cholesterol reduction was correlated with lycopene uptake (P = 0·003), whereas the other effects could not be related with particular micronutrients. Any beneficial effects of tomato consumption for human health cannot be attributed only to lycopene and, as the additional supplementation with ascorbic acid indicates, a variety of antioxidants might be needed to optimize protection against chronic diseases.

Interactions of hydroxyapatite and fluorapatite particles on human osteoarthritis type B synoviocytes: effects on interleukin-1 alpha levels and lipoxygenase pathways

We investigated the effects of the biomaterials hydroxyapatite (HAP) and fluorapatite (FAP) on cultured human osteoarthritis type B synoviocytes by analyzing interleukin-1 alpha (IL-1 alpha) production and arachidonic acid metabolism via lipoxygenase pathways. A portion of opsonized particles was endocytosed and was found in numerous phagolysosomes in human synoviocyte cytoplasms. The present study demonstrates that HAP and FAP calcined at 700 degrees C induced a decrease in IL-1 alpha production but markedly decreased the synthesis of lipoxygenase products after 1-month incubation with the particles. This model will allow us to study the possible inflammatory response (arachidonic acid metabolism, proinflammatory cytokines) that can be induced by any biomaterials used in orthopedics.

The clinical usefulness of the measurement of cytokines

The utilization of accurate and sensitive methods for the measurement of cytokines in body fluids is prerequisite for the proper use of these mediators in clinical practice. Many factors contribute to the complexity of cytokine quantitation. Bioassays historically preceded immunoassays, which are now very popular, but there is a need for standardization. Nevertheless, due to the local effects of cytokines, the study of their blood levels is of limited value for an understanding of the pathophysiology of these mediators. This explains the development of alternative approaches to assess the ability of cells to produce cytokines. These include the Enzyme-Linked Immuno Spot Assay (ELISPOT), the measurement of cell-associated cytokines by flow cytometry, and the study of cytokine secretion by isolated peripheral blood mononuclear cells or by whole blood test. All these techniques, associated with a local detection of cytokines by immunohistochemistry or in situ hybridization and reverse transcriptase polymerase chain reaction, appear to be complementary tools for a better understanding of the biology of cytokines. Selected examples of possible clinical applications related to infectious diseases, cancer, autoimmune diseases, allergy, transplantation and preclinical evaluation of drugs and biotechnology products are given.

Hypoxia stimulates proliferation and interleukin-1alpha production in human vascular smooth muscle cells

Several lines of evidence indicate that hypoxia is a stimulus to vascular smooth muscle cell (VSMC) proliferation that occurs in pulmonary hypertension. The present study tested the hypothesis that low O(2) tension directly stimulates human VSMC proliferation by inducing them to produce interleukin (IL)-1, a potent autocrine growth factor for human VSMC. Human VSMC derived from pulmonary artery, aorta, or saphenous vein were incubated in either a normal in vitro O(2) environment (20% O(2)) or in chambers containing low (approximately 1%) or moderate (5%) O(2). Levels of IL-1alpha and IL-1beta mRNA increased in human VSMC after 24-48 h of incubation in low O(2) compared with levels in normoxic cells and then decreased upon subsequent reoxygenation. Levels of cell-associated IL-1alpha also increased progressively after 24-48 h in low O(2); however, detectable IL-1alpha was not released from the cells in the media. IL-1beta was detectable in cell lysates and supernatants; however, the levels were not affected by exposure to low O(2). mRNA encoding for tumor necrosis factor-alpha (TNF-alpha), a related cytokine and VSMC mitogen, was not detectable in human VSMC exposed to either low or 20% O(2). Proliferation of human VSMC was not stimulated during exposure to low O(2), despite the fact that cells remained responsive to the mitogenic effect of exogenous IL-1. Interestingly, however, exposure to 5% O(2) enhanced proliferation of human VSMC but did not induce IL-1alpha production. Inhibition of IL-1 binding to the type I IL-1 receptor by exogenous addition of IL-1-receptor antagonist (10 microgram/ml) did not attenuate the proliferation rates of human VSMC incubated in 20%, 5%, or low O(2) or in human VSMC that were reoxygenated after exposure to low O(2). These results demonstrate two direct and distinct effects of hypoxia on VSMC. Exposure to moderately low O(2) tension induces VSMC proliferation, independent of IL-1, whereas exposure to very low O(2) tension induces production of IL-1alpha.

Overexpression of IL-1ra gene up-regulates interleukin-1beta converting enzyme (ICE) gene expression: possible mechanism underlying IL-1beta-resistance of cancer cells

We investigated the interaction of endogenous interleukin (IL)-1beta, IL-1ra, and interleukin-1beta converting enzyme (ICE) in four human urological cancer cell lines, KU-19-19, KU-1, KU-2 and KU-19-20. Northern blot analysis showed that IL-1beta gene was expressed in all cell lines. On the other hand, in KU-19-19 and KU-19-20, the gene expressions of both IL-1ra and ICE were suppressed. MTT assay revealed that IL-1beta (10 ng ml(-1)) promoted cell growth in KU-19-19 and KU-19-20, while it inhibited in KU-1 and KU-2. An ICE inhibitor, Acetyl-Tyr-Val-Ala-Asp-CHO (YVAD-CHO) blocked IL-1beta-induced growth inhibition in KU-1 and KU-2. Overexpression of the secretory type IL-1ra with adenovirus vector (AxlL-1ra) enhanced ICE gene expression, while exogenous IL-1ra (100 ng ml(-1)) did not enhance it. Furthermore, AxIL-1ra treatment promoted endogenous IL-1beta secretion and induced significant growth inhibition and apoptotic cell death on KU-19-19 and KU-19-20. Treatment with either IL-1ra (100 ng ml(-1)), IL-1beta antibody (100 microg ml(-1)), or YVAD-CHO blocked AxlL-1ra-induced cell death in KU-19-19 and KU-19-20. These results suggest that IL-1beta-sensitivity depends on the level of ICE gene expression, which is regulated by the level of endogenous slL-1ra expression. This is a first report on the intracellular function of slL-1ra and these findings may provide key insights into the mechanism underlying the viability of cancer cells.

Interleukin-1beta in synovial fluid from the arthritic temporomandibular joint and its relation to pain, mobility, and anterior open bite

PURPOSE

The purpose of this study was to investigate whether interleukin-1beta in synovial fluid or blood plasma is involved in the development of pain or hyperalgesia of the temporomandibular joint (TMJ), as well as reduced mandibular mobility and anterior open bite.

PATIENTS AND METHODS

Twenty-nine patients with TMJ arthritis and seven healthy subjects were studied. VAS measurement of TMJ tenderness on palpation of the TMJ (TDP), TMJ pressure pain threshold and tolerance level (PPTL), mandibular mobility, pain during joint movements, and degree of anterior open bite (AOB) were assessed. IL-1beta levels were analyzed in TMJ synovial fluid (SF-IL-1beta) and blood samples and correlated with the preceding factors.

RESULTS

SF-IL-1beta showed significant positive correlations with VAS measurement of pain, TDP, and AOB and a negative correlation with PPTL.

CONCLUSIONS

This study indicates that IL-1beta in the synovial fluid is associated with pain and hyperalgesia in the TMJ region as well as an anterior open bite. Concerning the latter condition, IL-1beta seems to be a warning signal of tissue destruction.

Nasal response in subjects undergoing challenges by inhaling occupational agents causing asthma through the nose and mouth

BACKGROUND

Subjects with occupational asthma (OA) often report nasal symptoms, but nasal reactions to inhalation challenges with occupational agents have not been well characterized.

METHODS

Fifteen subjects with OA (eight due to high-molecular-weight agents--flour and guar gum--and seven due to isocyanates) underwent inhalational challenges using closed-circuit devices (dry particles for high-molecular-weight agents and gas generator for isocyanates) on two occasions, 2-4 weeks apart in a random fashion. On one occasion, they inhaled through the nose and, on another, through the mouth. The FEV1 was monitored for up to 8 h afterward, and symptoms were documented with a standardized questionnaire on nasal symptomatology, assessment of nasal resistance by rhinomanometry, and nasal lavage for the examination of cells and mediators.

RESULTS

Inhaling through the mouth and through the nose: 1) yielded similar asthmatic responses (25+/-8% and 22+/-10% maximum changes in FEV1) 2) more than doubled the peak nasal symptoms and nasal resistance when the maximum daily response was compared with prechallenge results. This increase occurred on the days of inhalational challenges through the mouth and through the nose. There were some significant responses assessed by nasal lavage in terms of cells and mediators, again with no differences between the days of challenges through the mouth and through the nose.

CONCLUSIONS

Inhaling occupational agents of high or low molecular weight, including isocyanates, whether through the mouth or nose: 1) results in a similar asthmatic response 2) causes a significant nasal response in terms of symptoms and an increase in nasal resistance 3) causes some significant changes in inflammatory cells and mediators.

The influence of neuropeptides, serotonin, and interleukin 1beta on temporomandibular joint pain and inflammation

PURPOSE

This article describes the possible role of various peptides in producing pain and inflammation in the temporomandibular joint (TMJ).

MATERIAL AND METHODS

Current research findings on the spectrophotometric quantification of TMJ synovial fluid for neuropeptide Y (NPY), serotonin (5HT), and interleukin-1beta (IL-1beta) are presented.

FINDINGS

NPY was found in high levels in the synovial fluid of arthritic TMJs with resting pain, and serotonin (5-HT) was found in patients with pain perceived on mandibular movement. These pain-related mediators were also associated with restricted mandibular mobility. Interleukin-1beta (IL-1beta) was found to be strongly associated with hyperalgesia over the TMJ as well as resting pain. Anterior open bite as a clinical sign of joint destruction was found to be associated with high levels of NPY and IL-1beta in the synovial fluid. IL-1beta was also related to the radiographic signs of joint destruction.

CONCLUSIONS

Interaction between the peripheral nervous system (sensory and sympathetic nerves) and the immune system is probably of importance for the modulation of pain and inflammation in the TMJ, but this subject has to be investigated further with experimental clinical studies.

Lipopolysaccharide Activates Caspase-1 (Interleukin-1–Converting Enzyme) in Cultured Monocytic and Endothelial Cells

Interleukin-1β (IL-1β) is a pleiotropic proinflammatory cytokine. Mechanisms leading to its secretion include not only release of newly synthesized protein, but also cleavage of a preformed immature precursor protein into an active secretory form by the intracellular protease caspase-1 (formerly termed IL-1–converting enzyme [ICE]). Caspase-1 belongs to a rapidly growing family of cysteine proteases with substrate specificity for aspartate involved in cellular apoptosis. We have used an assay determining the caspase-1 activity based on cleavage of a fluorogenic peptide substrate to elucidate its role in lipopolysaccharide (LPS)-induced secretion of IL-1β. We show that LPS induces moderate caspase-1 activity in the monocytic cell line THP-1, in freshly isolated peripheral blood monocytes, and in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent fashion. Caspase-1 activation by LPS was associated with cleavage of the IL-1β precursor protein that was followed by release of the mature IL-1β protein in monocytic cells. In contrast, subsequent release of IL-1β by HUVECs was not significant. LPS-induced caspase-1 activation appeared not to result from modulation of caspase-1 transcript accumulation and inhibition of caspase-1 activity was accomplished by two specific inhibitors, YVAD-CHO and YVAD-CMK, capable of alleviating the release of mature IL-1β. Taken together, these results show that LPS moderately activates caspase-1 and that caspase-1 activation contributes to LPS induction of IL-1β secretion.

Lipopolysaccharide Activates Caspase-1 (Interleukin-1–Converting Enzyme) in Cultured Monocytic and Endothelial Cells

Interleukin-1β (IL-1β) is a pleiotropic proinflammatory cytokine. Mechanisms leading to its secretion include not only release of newly synthesized protein, but also cleavage of a preformed immature precursor protein into an active secretory form by the intracellular protease caspase-1 (formerly termed IL-1–converting enzyme [ICE]). Caspase-1 belongs to a rapidly growing family of cysteine proteases with substrate specificity for aspartate involved in cellular apoptosis. We have used an assay determining the caspase-1 activity based on cleavage of a fluorogenic peptide substrate to elucidate its role in lipopolysaccharide (LPS)-induced secretion of IL-1β. We show that LPS induces moderate caspase-1 activity in the monocytic cell line THP-1, in freshly isolated peripheral blood monocytes, and in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent fashion. Caspase-1 activation by LPS was associated with cleavage of the IL-1β precursor protein that was followed by release of the mature IL-1β protein in monocytic cells. In contrast, subsequent release of IL-1β by HUVECs was not significant. LPS-induced caspase-1 activation appeared not to result from modulation of caspase-1 transcript accumulation and inhibition of caspase-1 activity was accomplished by two specific inhibitors, YVAD-CHO and YVAD-CMK, capable of alleviating the release of mature IL-1β. Taken together, these results show that LPS moderately activates caspase-1 and that caspase-1 activation contributes to LPS induction of IL-1β secretion.

Epstein-Barr virus induces GM-CSF synthesis by monocytes: effect on EBV-induced IL-1 and IL-1 receptor antagonist production in neutrophils

Neutrophils play an important role in the control of viral infections by releasing a variety of potent agents. We previously demonstrated that Epstein-Barr virus (EBV) binds to human neutrophils and stimulates cytokine synthesis including interleukin-1 (IL-1) and IL-1 receptor antagonist (IL-1Ra). Since neutrophil functions are known to be modulated by the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), we therefore investigated the cellular source of GM-CSF synthesis following treatment of leukocytes with EBV and the effect of GM-CSF on the production of IL-1, IL-1Ra, and superoxide by EBV-treated neutrophils. In enriched-cell populations, only monocytes were found to produce GM-CSF in response to EBV, which was maximal after 12 h of incubation. The results obtained with UV-irradiated particles or EBV neutralized with monoclonal antibody 72A1 suggest that contact between the cell and the gp350 of the viral envelope is sufficient to induce the release of GM-CSF. On the other hand, GM-CSF differentially upregulated EBV-induced IL-1 and IL-1Ra production by neutrophils. Pretreatment of neutrophils with GM-CSF prior to EBV activation synergistically enhanced the production of IL-1 alpha and IL-1 beta, but only marginally affected IL-1Ra synthesis. In addition, GM-CSF was also found to synergistically enhance the superoxide production by neutrophils in response to EBV. Molecular analysis showed that GM-CSF did not alter the IL-1 beta and IL-1Ra mRNA synthesis induced by EBV, suggesting that GM-CSF could act at a posttranslational level. Local production of GM-CSF by monocytes in tissues invaded by EBV could serve to potentiate the host defense mechanisms directed toward the destruction of the infectious virus.

Signaling pathway triggered by a short immunomodulating peptide on human monocytes

A short synthetic peptide (Pa) containing a structural motif ("2-6-11" motif) present in a number of human extracellular matrix proteins was found to stimulate the production of cytokines IL-1alpha, IL-1beta, IL-6, and TNFalpha by human peripheral blood mononuclear cells. We have now investigated the signal transduction pathway involved in the elicitation of these immunomodulating properties on isolated human monocytes. Our results show that active peptide Pa provoked phosphoinositide hydrolysis, intracellular calcium elevation, and cAMP accumulation. Herbimycin A, an inhibitor of protein tyrosine kinases (PTK), markedly reduced these effects of peptide Pa. We have also found that this peptide stimulated CREB, NF-kappaB, and AP-1 DNA-binding activity. With the help of inhibitors of PTK (herbimycin A), phospholipase C (neomycin sulfate), protein kinase C (bis-indolyl maleimide), protein kinase A (H89), and the calmodulin antagonist W-7, as well as cholera toxin, an agent that increases intracellular cAMP, we showed that cytokine (IL-1alpha, IL-1-beta, IL-6, and TNFalpha) production could be modified by the signal transduction pathway triggered by peptide Pa on monocytes.

Measurement of cytokine antibodies. Test development

Several assays have been used for detection of antibodies against cytokines. The choice of assay is greatly dependent on the intended goal, e.g. detection of naturally occurring antibodies or therapy induced antibodies. The different assays can be grouped in 2 categories. The interference or indirect assays are based on the detection of the test sample interference with the biological activity, with detection of the cytokine in EIA or with binding to cellular receptors. In direct assays cytokine antibodies are detected by binding to solid phase fixed cytokines, followed by incubation with a secondary enzyme-labelled anti-human Ig antibody or by binding to 125I-labelled cytokines in RIA.

Increased incidence of neutralizing autoantibodies against interleukin-1 alpha (IL-1 alpha) in nondestructive chronic polyarthritis

Cytokines such as IL-1 and tumor necrosis factor alpha (TNF alpha) play a critical role in chronic joint inflammation and destruction. To study their regulation, we looked for circulating antiproinflammatory cytokine autoantibodies in 318 patients with chronic arthritis by immunoprecipitation with protein G. Anti-IL-1 alpha but not anti-IL-1 beta or anti-TNF alpha IgG antibodies were detected in 9% of blood donors and 18.9% of chronic arthritis patients. These antibodies were found more commonly and at a higher level in patients with nondestructive arthritis. Negative correlations were observed between the antibody levels and indices of disease activity and joint destruction. There was a negative association between the presence of anti-IL-1 alpha antibodies and that of HLA-DR4. These circulating anti-IL-1 alpha antibodies were not complexed with IL-1 alpha and could block specifically the biological activity of IL-1 alpha and its binding to membrane IL-1 receptors. These results indicate that these antibodies are beneficial, suggesting their contribution in the clinical presentation.

Interleukin-1 beta converting enzyme in murine Langerhans cells and epidermal-derived dendritic cell lines

Interleukin (IL)-1 beta plays an essential role in the induction of T cell-mediated immune responses in skin. Langerhans cells (LC), which constitutively express IL-1 beta mRNA, have been assumed to be the primary source of IL-1 beta in murine epidermis. The purpose of this study was to determine whether LC express mRNA for the IL-1 beta converting enzyme (ICE), a protease that is required for processing pro-IL-1 beta into an active form. Here, we report that both IL-1 beta and ICE mRNA are expressed by the Ia+ population (i.e. LC) in murine epidermis. Moreover, murine epidermal-derived DC lines (XS series) also express both IL-1 beta and ICE mRNA, and they secrete relatively large amounts of IL-1 beta following lipopolysaccharide (LPS) stimulation. Finally, LPS-triggered IL-1 beta secretion by XS cells is blocked almost completely by the ICE inhibitor acetyl-Tyr-Val-Ala-Asp-CH2OC(O)-[2,6-(CF3)2]Ph. These results demonstrate that LC are the primary source of IL-1 beta within the epidermis, and suggest that the proinflammatory role of IL-1 beta may be regulated pharmacologically by ICE inhibitors in vivo.

Rapid, comprehensive analysis of human cytokine mRNA and its application to the study of acute renal allograft rejection

Cytokine mRNA analysis was performed on human renal allograft needle core biopsies by a PCR-based assay. The assay was specifically developed to be capable of simultaneous analysis of multiple interleukin transcripts (IL-1-IL-12), as well as those of other relevant cytokines, by one person in less than 1 day from cultured cells or directly from tissue samples. It was initially used on preparations containing known amounts of plasmid DNA encoding individual cytokine cDNA sequences, confirming that the sensitivity of this technique was both well defined and comparable for all target sequences tested. Analysis of human PBLs prior to stimulation, after polyclonal stimulation with PHA and after simultaneous treatment with PHA and MP or CyA, was also performed to show a proportional relationship between mRNA levels measured by PCR and protein release measured by ELISA (R2 = 0.86). This correlation was not adversely altered by pharmacologic immunosuppression by MP or CyA. Thus, this method of PCR primer design and usage was appropriate for the clinical study of cytokine mRNA levels during allograft rejection. Direct study of cytokine mRNA in allograft biopsy tissue showed that IL-2 was specifically and significantly (p = 0.006) elevated during ACR when compared to other causes of graft dysfunction. Transcripts from the IFN-gamma and IL-6 genes were also increased in ACR (p = 0.001 and 0.017, respectively), whereas increased IL-8 mRNA was correlated with irreversible loss of graft function (p = 0.02). TNF-alpha, IL-1 beta, and IL-10 gene transcripts were also detected during ACR, but were not quantitatively increased compared to other forms of graft injury (p > 0.2). We conclude that acute cellular rejection is associated with intragraft mRNA from the IL-2 gene. Other transcripts, including those from the IFN-gamma, IL-6, and IL-8 genes, are detected in increased amounts during this process. Messenger RNA from the TNF-alpha, IL-1 beta and IL-10 genes is also detected during ACR, but the presence of these transcripts is not exclusive to this process.

The effects of smokeless tobacco on clinical parameters of inflammation and gingival crevicular fluid prostaglandin E2, interleukin-1 alpha, and interleukin-1 beta

The purpose of this study was to examine the effect of smokeless tobacco (ST) on gingival inflammation as assessed clinically and biochemically by gingival crevicular fluid (GCF) levels of PGE2, IL-1 alpha, and IL-1 beta. These parameters were compared in ST users (n = 12) and control, non-tobacco using subjects (n = 8) matched for plaque and probing depth levels. Both GI and GCF PGE2 concentration were significantly (P < 0.05) elevated at ST placement sites compared to sites in control subjects. A short-term longitudinal trial spanning 7 days also was undertaken within ST users (n = 18) to study the dynamics of gingival inflammation when ST is moved to a new site. At day 0 habitual ST placement sites exhibited a significantly (P < 0.05) higher GI compared to non-tobacco placement sites. Following transfer of ST to a new placement site, 48 hour GI scores were increased (P < 0.05) at this region. Although GCF parameters were not significantly altered, over 80% of the subjects developed dramatic inflammatory reactions in the alveolar mucosa, ranging from erythema to ulceration, at the new site of placement. This observation of a more severe response in alveolar mucosa compared to gingiva may be related to the physical location of ST or differences in tissue characteristics.

Cytokine autoantibodies in rheumatoid arthritis

Sera from 42 patients with rheumatoid arthritis (RA) and 40 healthy controls (HC) were examined for cytokine autoantibodies (CK-aAb) by accurate and sensitive radioimmunoassays. The prevalences of detectable CK-aAb in RA (HC) were: aAb-IL-1 alpha = 36% (38%); aAb-IL-6 = 29% (13%), p = 0.06; aAb-IL-8 = 0% (0%); aAb-IFN alpha = 12% (3%), p = 0.11. The levels of the individual CK-aAb did not correlate, and there were no correlations between CK-aAb levels and clinical or laboratory variables. CK-aAb levels remained constant in 8 RA patients tested over a period of 6 months. With regard to alterations in aAb-IL-1 alpha levels, 4/11 HC were consistently positive over 18-36 months; 2/11 converted and became highly positive. The levels of aAb-IFN alpha and aAb-IL-6, but not aAb-IL-1 alpha, tended to be increased in RA patients; aAb-IL-8 were undetectable in both RA and HC.

Increased concentrations of interleukin-6 and interleukin-1 receptor antagonist and decreased concentrations of beta-2-glycoprotein I in Gambian children with cerebral malaria

To investigate the pathogenic versus the protective role of cytokines and toxin-binding factors in Plasmodium falciparum infections, we measured the concentrations of tumor necrosis factor alpha, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist, and IL-6, as well as soluble receptors of tumor necrosis factor and IL-6 (sIL-6R) in serum of Gambian children with cerebral malaria, mild or asymptomatic malaria, or other illnesses unrelated to malaria. Because cytokine secretion may be triggered by toxic structures containing phosphatidylinositol (PI), we also measured concentrations of anti-PI antibodies and the PI-binding serum protein beta-2-glycoprotein I. We found increased concentrations of IL-6, sIL-6R, IL-1ra, and some immunoglobulin M antibodies against PI in children with cerebral malaria, but those who died had decreased concentrations of beta-2-glycoprotein I. We conclude that increased concentrations of cytokines and soluble cytokine receptors represent a normal host response to P. falciparum infections but that excessive secretion of cytokines like IL-6 may predispose to cerebral malaria and a fatal outcome while beta-2-glycoprotein I may protect against a fatal outcome of cerebral malaria.

Enzyme immunometric assay for leukotriene C4

An enzyme immunometric assay of LTC4 named SPIE-IA is described. The assay involves different sequential steps: (1) immunocapture of LTC4 by monoclonal anti-LTC4 antibodies coated on 96-well microtiter plates; (2) cross-linking of LTC4 via its amino group to the wells using glutaraldehyde; (3) treatment with HCl; (4) measurement of linked LTC4 using the same monoclonal anti-LTC4 antibodies labeled with acetylcholinesterase. A minimal detectable concentration of 2 pg/ml after 60 min of enzymatic reaction was obtained. Cross-reactivity was less than 15% with LTD4 or LTE4. The coefficient of variation was less than 6% in the 20-1000 pg/ml range. Good correlation was observed between SPIE-IA and a competitive enzyme immunoassay for biological samples. The different sequential steps of the assay are investigated.

Interleukin-1B: a clinically relevant urinary marker

Urinary cytokines as markers for the intravesical inflammatory response have become an active area of research. Interleukin-1b, a well studied and early produced cytokine in the immune recognition cascade, was evaluated. After extensive analysis of 56 control and study group urine samples, a simplified and reliable protocol for the preparation of urine before cytokine analysis was devised. The application of an available serum interleukin-1b enzyme-linked immunosorbent assay kit for urinary interleukin-1b analysis was then tested. Finally, a reference value for interleukin-1b in normal human urine was established and urinary interleukin-1b was measured in various bladder diseases. The normal and interstitial cystitis groups showed no interleukin-1b elevation. Significant elevation of urinary interleukin-1b was found in patients with bacterial cystitis compared to the interstitial cystitis and control groups (p < 0.001). Of the patients with bladder tumors 58% showed elevation of urinary interleukin-1b (p < 0.001). Urinary interleukin-1b may be used as a marker to distinguish between bacterial and interstitial cystitis. The absence of urinary interleukin-1b in interstitial cystitis argues against an immunological or autoimmune etiology of the disorder. This study represents an important methodological approach to cytokine subtyping of bladder diseases.

Immunoassay for functional human soluble interleukin-6 receptor in plasma based on ligand/receptor interactions

Soluble forms of most cytokine receptors, able to bind effectively to their respective ligands, have now been described. A soluble interleukin-6-binding molecule derived from the gp80 component of the multichain IL-6 receptor can be detected in biological fluids, and can act as an agonist of IL-6 activity. The clinical significance of the soluble receptor levels still remains to be explored. We took advantage of the characterization of an anti-IL-6 monoclonal antibody and of an anti-IL-6R monoclonal antibody that both bound to IL-6/IL-6R complexes to design an immunometric assay for the measurement of soluble IL-6R complexed to IL-6. This reaction scheme was designated as ELIA (enzyme-ligand immunoassay). When exogeneous IL-6 was added in excess to an sIL-6R containing sample, all sIL-6R was present in a complexed form. Thus, the reaction scheme could also be used to determine total sIL-6R concentrations. A recombinant sIL-6R standard was prepared from the supernatant of murine thymoma cells transfected with a gene coding for an extracellular portion of the IL-6 receptor. The assay permitted the precise and reproducible measurement of sIL-6R in serum or plasma. This approach is of general relevance for the determination of soluble cytokine receptors in biological fluids, provided that adequate anti-cytokine and anti-receptor antibodies are available.

Enzyme immunometric assay for endothelin using tandem monoclonal antibodies

Seven distinct mouse monoclonal antibodies (mAbs) directed against human endothelin-1 (ET-1) have been obtained. On the basis of specificity studies performed with competitive immunoassays and of complementary binding studies, these mAbs were classified in two groups. mAbs of group A (Endo-4, -5, -6 and -10) were shown to be directed against the N terminal loop while those of group B (Endo-2, -8 and -18) recognized the C terminal part of the peptide. A pair of monoclonal antibodies with optimal properties for a two-site immunometric assay were selected and the test was performed in 96-well microtiter plates coated with one mAb (Endo-18), while another mAb (Endo-4) covalently labeled with enzyme acetylcholinesterase was used as tracer. Under optimal conditions, the assay appeared to be very sensitive since concentrations as low as 1 pg/ml could be significantly detected. The precision was also very good with a coefficient of variation below 10% from 3 to 250 pg/ml. The assay was specific for mature endothelin presenting no cross-reactivity with the precursor Big ET-1. On the other hand, strong cross-reactivity was observed with other ET-1-related peptides, including ET-2, ET-3, VIC peptide and sarafotoxin 6-b. The assay permitted specific determination of ET-1 in supernatants of cultured endothelial cells and the validity of the test was demonstrated by HPLC fractionation experiments. In addition, the assay also appeared to be suitable for direct determination of ET-1 in plasma. Studies performed with plasma from healthy subjects revealed that circulating levels of ET-1 are below or close to the detection limit of the method (< 8 pg/ml).

Effects of experimental conditions on the production of interleukin-1 alpha and -1 beta by human endothelial cells cultured in vitro

We have characterized the production of IL-1 alpha and -beta in primary and passaged cultures of quiescent human umbilical vein endothelial cells (HUVECs) using highly specific and sensitive solid-phase enzyme immunoassays. Primary cultures produced both immunoreactive IL-1 alpha and IL-1 beta following stimulation with lipopolysaccharide with the alpha form predominating over the beta. Most of the IL-1 produced remained cell-associated. Primary, but not passaged, cultures were significantly contaminated by macrophage-like cells, possibly accounting for higher production of IL-1, especially IL-1 beta. Gel filtration of secreted proteins derived from cultured HUVECs showed that the immunoreactive IL-1 alpha exhibited the expected molecular weight (17 kDa), but cell-associated IL-1s appeared to be a mixture of the 17 kDa protein and of higher molecular weight precursors. Mitogens in the culture medium (serum and endothelial cell growth supplement) were powerful stimuli of endothelial IL-1 production and accounted for the relatively high basal IL-1 levels observed in the cultured endothelial cells. The proliferative phenotype of the endothelium is possibly linked to the expression of high level of IL-1, which until now was thought to be an autocrine inhibitor of endothelial cell mitosis.