There is more than one interleukin 1

Species-specific binding of IL-1, but not the IL-1 receptor antagonist, by fibroblasts

Our laboratory previously reported that bovine thymocytes and fibroblasts proliferated only in response to bovine IL-1, whereas proliferation of murine thymocytes was augmented equally well by murine, human, and bovine IL-1. In this study, we used direct and competitive receptor binding assays to determine whether differential binding of homologous versus heterologous IL-1 accounts for the species-specific response of bovine fibroblasts. Our results demonstrated that bovine and human fibroblasts bound homologous IL-1 with high affinity and heterologous IL-1 with lower affinity. In contrast, murine fibroblasts bound both homologous and heterologous IL-1 with high affinity. Because IL-1 and the human IL-1 receptor antagonist (IL-1ra) both bind to type 1 IL-1 receptors, we also determined whether the IL-1ra demonstrated receptor binding properties similar to human IL-1 for bovine, human, and murine fibroblasts. To our surprise, the human IL-1ra bound equally well to bovine, human and murine fibroblasts. We used this characteristic of the IL-ra to perform affinity cross-linking analysis of the IL-1 receptors on bovine, human and murine fibroblasts. These comparisons demonstrated the IL-1 receptors on bovine and human fibroblasts have similar molecular sizes (M(r) 73 kDa and M(r) kDa, respectively), whereas, IL-1 receptors on murine fibroblasts have an estimated molecular size of M(r) 88 kDa. These data demonstrate that IL-1 receptors on bovine fibroblasts preferentially bind homologous IL-1, but bovine fibroblasts do not discriminate binding by the human IL-1ra. In contrast, murine fibroblast IL-1 receptors bind heterologous IL-1 with high affinity.

Mouse interleukin-1 receptor antagonist induced by Actinobacillus actinomycetemcomitans lipopolysaccharide blocks the effects of interleukin-1 on bone resorption and osteoclast-like cell formation

We have reported that P388D1 cell line murine macrophages stimulated with lipopolysaccharide (LPS) from Actinobacillus actinomycetemcomitans release interleukin-1 (IL-1) inhibitor. The IL-1 inhibitor was purified from conditioned media of P388D1 cells stimulated with A. actinomycetemcomitans LPS for 72 h to homogeneity by a four-step procedure: acetic acid extraction from conditioned media; Bio-Gel P-60 gel filtration chromatography; DEAE-Sepharose CL-6B column chromatography; and reverse-phase high-performance liquid chromatography on a C18 hydrophobic support. The purified IL-1 inhibitor gave a single band of protein with a molecular mass of 26 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified IL-1 inhibitor was a heat- and acid-stable protein that was inactivated by digestion with trypsin and reduction with dithiothreitol. This inhibitory factor suppressed the proliferation of C3H/HeJ mouse thymocytes and the proliferation of IL-1-dependent cell lines, D10.G4.1 and RPMI 1788, induced by IL-1. However, this inhibitor did not affect the proliferation of IL-2-dependent CTLL-2 cells induced by IL-2, the proliferation of C3H/HeJ mouse thymocytes stimulated with a mitogenic dose of concanavalin A, and the proliferation of IL-6-dependent B9 cells induced by IL-6. Furthermore, the IL-1 inhibitor significantly blocked stimulation of bone resorption in organ cultures of newborn mouse calvaria and inhibited the osteoclast-like cell formation in mouse marrow cultures. A monoclonal antibody prepared against the purified IL-1 inhibitor reacted with mouse recombinant IL-1 receptor antagonist (rIL-1ra), and a polyclonal antibody to mouse rIL-1ra reacted with the IL-1 inhibitor by Western blot (immunoblot) analysis. These results indicate that the IL-1 inhibitor is an identical molecule to rIL-1ra, suggesting that the IL-1 inhibitor (IL-1ra) released by macrophages stimulated with LPS from A. actinomycetemcomitans may play an important mediative role in the development of periodontal disease.

Cytokine intervention permits dose escalation of radioantibody. An analysis of myelostimulation by bolus versus continuous infusion of IL-1/GM-CSF

BACKGROUND

The authors recently reported that a 12-day schedule (beginning 3 days before radioantibody treatment) of twice-daily dosing of rH-IL-1 (1 x 10(3) U/dose) and rM-GM-CSF (0.5 micrograms/dose) can reduce the magnitude and duration of radioantibody-induced myelosuppression, thereby permitting a 25-30% increase in the dose of radioantibody that can be administered without the dose proving lethal. In an effort to further reduce toxicity and escalate the tolerated dose, the authors altered the method of administration of cytokines from daily bolus dosing to continuous infusion by implantable osmotic pumps.

METHODS

A control group of mice was compared to five groups of mice that either did or did not receive a 340 microCi dose of radioantibody, and received no cytokines, cytokines by bolus dosing, or cytokines by continuous infusion. For 4 weeks, peripheral white blood cell and thrombocyte counts and thymus and spleen weights were taken, marrow cell number was monitored, and marrow colony-forming unit activity was evaluated weekly in the untreated control mice and the treated mice.

RESULTS

These studies demonstrated that after a dose of radioantibody, continuous dosing of cytokines resulted in higher white blood cell (WBC) and platelet values than if bolus delivery was used (day 7, WBC: 110% vs. 59%; day 14, WBC: 85% vs. 62%; day 21, WBC: 98% vs. 42%; day 7, platelets: 122% vs. 51%; day 14, platelets: 159% vs. 72%; day 21, platelets: 239% vs. 171%). A comparison of bolus versus continuous dosing in the absence of radioantibody indicated that spleen weight increased by 40-60% after continuous infusion of cytokines and by 20-25% after bolus dosing. The 20-30% decrease in thymus weight was similar with both dosing regimens. Colony-forming units (CFUs) in marrow increased from 30-35 in untreated mice to 50-55 in mice given cytokines by bolus injection, and to 150-180 in mice given continuous infusion of cytokines. Spleen CFUs exhibited an insignificant increase after bolus dosing of cytokines but increased almost fourfold after continuous dosing. Peak stimulation of marrow and spleen CFUs occurred 28 days after initiation of cytokine administration (2 weeks after cytokines administration was stopped). The probability of survival for 6 weeks after further dose escalation to 360 microCi I-131-MN-14 immunoglobulin G was 16.4% +/- 8.6% after bolus dosing and 58.1% +/- 11.3% after continuous infusion of cytokines.

CONCLUSIONS

Although continuous infusion of cytokines proved to be a better method of reducing hematopoietic toxicity, further dose escalation of radioimmunotherapy using the "pump" method of cytokine delivery was not possible. Cytokine intervention by either mode of delivery permits a 25% dose intensification without the dose becoming lethal. Further escalation is not feasible, possibly because of other end organ toxicity.

In vivo and in vitro analysis of membranes from hip prostheses inserted without cement

Biochemical, histological, and immunohistochemical studies of interface membranes surrounding failed hip prostheses that had been inserted without cement were done to examine specific factors involved in the development of aseptic loosening. Membranes from sixty-four femoral components were obtained from sixty-three patients during revision arthroplasty. Fifty-seven membranes were from implants that articulated with polyethylene (thirty-two were made of cobalt-chromium alloy and twenty-five, titanium alloy), and seven were from unipolar endoprostheses made of cobalt-chromium alloy that did not articulate with polyethylene. The membranes from implants with a polyethylene articulation produced significantly higher levels of collagenase and interleukin-1 (p < 0.05). However, there was no significant difference in the levels of prostaglandin E2 between the three groups. Furthermore, membranes from implants with roentgenographic evidence of focal osteolysis (endosteal erosion) released significantly higher levels of interleukin-1 (p < 0.05) than did membranes from implants without focal osteolysis. Although the membranes from the titanium-alloy implants tended to contain more metal debris than those from the cobalt-chromium-alloy implants, the biochemical findings were not significantly different between these two groups. Many macrophages that were filled with polyethylene and metal debris were present in the membranes from both groups with a polyethylene articulation. Few T lymphocytes or B lymphocytes were identified in the three groups.

Resistance to the anti-proliferative effect of IL-1 on human melanoma cell line is associated with endogenous production of IL-1 and IL-6

A human melanoma cell line (A375-6) became resistant to the anti-proliferative effect of human IL-1 after a long period of culture. Two stable resistant sub-clones were obtained, and the mechanism of the IL-1 resistance was investigated. Resistant cells, but not sensitive cells, appeared to produce constitutively IL-1 activity. The activity was neutralized by anti-IL-1 alpha antibody but not by anti-IL-1 beta antibody. Resistant cells expressed IL-1 alpha but not IL-1 beta mRNA. Therefore, the resistant cells appeared to produce IL-1 alpha mRNA for IL-1 receptor antagonist (IL-1Ra) was not detected in resistant cells, indicating that the resistance is not attributable to IL-1Ra. These resistant cells were also resistant to the anti-proliferative effect of human IL-6, but not to that of human TNF. Resistant cells appeared to produce constitutively IL-6 more than sensitive cells, and IL-6 production both in sensitive and in resistant cells was augmented by exogenous IL-1. Furthermore, constitutive production of IL-6 in resistant cells was inhibited by IL-1Ra. Type I IL-1 receptor (IL-1R) mRNA was expressed equally in resistant and sensitive cells. These data indicate that the resistance is not the result of loss of functional IL-1R and that IL-1 induces IL-6 in an autocrine manner. It is, therefore, conceivable that endogenous IL-1 and IL-6 contribute to IL-1 resistance.

Quantification of recombinant human interleukin-1 alpha by a specific two cell immunobioassay

The detection of picogram quantities of recombinant human IL-1 alpha in human and rat serum was accomplished by a sensitive and specific two cell immunobioassay. The specificity is provided by an IL-1 alpha specific mouse IgM monoclonal antibody which is non-neutralizing thus allowing for the addition of the EL-4 NOB-1 cell line directly to the IL-1 alpha monoclonal antibody complex. The above cell line is then converted to an IL-2 producer line in response to the captured IL-1 alpha. Supernatant from the EL-4 NOB-1 cells is then added to the IL-2 dependent CTLL-2 line and cell proliferation measured by thymidine incorporation. This assay has the advantage of specificity provided by the antibody capture step, sensitivity provided by the EL-4 NOB-1 line (1-50 pg/ml) and finally ease of maintenance of the responder cell line which requires no feeder cells or mitogens. Data are reported on the sensitivity, precision, reproducibility and specificity of the assay, the stability of rhIL-1 alpha in serum and the recovery of rhIL-1 alpha from serum. We also report on the use of this procedure to assay samples from rats given ascending doses of rhIL-1 alpha.

Centrally active differentiation factors in the nervous system

The adult mammalian brain is a remarkably heterogeneous structure comprised of more than 50 biochemically distinct types of neurons. This phenotypic diversity is established during development, not only as the result of genetic but also epigenetic influences. It is believed that extracellular proteins, called differentiation factors, both instruct neurons in their original choice of neurotransmitter substance and, in certain situations, revise those biochemical decisions. The first candidate differentiation factor in the brain has only recently been proposed. This muscle-derived substance has the unique ability, in culture, to initiate expression of genes associated with catecholamine transmitter synthesis in non-catecholamine neurons of the brain. Because it also amplifies expression in cultured catecholamine-producing neurons in vitro and in vivo, it may prove to be an important therapeutic agent in diseases involving catecholamine shortages.

Activation of the hypothalamus-pituitary-adrenal axis by bacterial endotoxins: routes and intermediate signals

Peripheral administration of endotoxin induces brain-mediated responses, including activation of the hypothalamus-pituitary-adrenal (HPA) axis and changes in thermoregulation. This paper reviews the mechanisms by which endotoxin affects these responses. The effects on thermoregulation are complex and include macrophage-dependent hyperthermic and hypothermic responses. Low doses of endotoxin, given IP, activate peripheral macrophages to produce interleukin (IL)-1 beta, which enters the circulation and acts as a hormonal signal. IL-1 may pass fenestrated endothelium in the median eminence to stimulate corticotropin-releasing hormone (CRH) secretion from the CRH nerve-terminals. In addition, IL-1 may activate brain endothelial cells to produce IL-1, IL-6, prostaglandins, etc., and secrete these substances into the brain. By paracrine actions, these substances may affect neurons (e.g., CRH neurons) or act on microglial cells, which show IL-1-induced IL-1 production and therefore amplify and prolong the intracerebral IL-1 signal. In contrast, high doses of endotoxin given i.v. may directly stimulate endothelial cells to produce IL-1, IL-6, and prostaglandin-E2 (PGE2) and thereby activate the HPA axis in a macrophage-independent manner.

Augmented local immunity in the liver by a streptococcal preparation, OK432, related to antitumor activity of hepatic macrophages

The aim of this study was to investigate the augmentative effect of a streptococcal preparation, OK432, on the immunological competence of hepatic macrophages. We found that OK432 was distributed predominantly to hepatic macrophages after intravenous injection, and Northern blot analysis revealed that OK432 induced the gene expression of IL-1 alpha, beta, and TNF alpha in the liver. The induction of mRNAs was evident 1 h after the intravenous injection of OK432 and their accumulation reached a maximal level at 3 h. TNF production of hepatic macrophages was also increased by the intravenous injection of OK432. Furthermore, OK432 significantly increased the proportion of IL-2 receptor-positive hepatic macrophages. As for antitumor activity in the liver being augmented by OK432, the cytotoxic and cytostatic activity of hepatic macrophages from OK432-treated rats against tumor cells was significantly increased and OK432 markedly reduced the number of tumor nodules in the liver after the inoculation of tumor cells via the portal vein. These findings, which indicate that OK432 has various immuno-stimulating actions on hepatic macrophages, leading to the augmentation of antitumor activity in the liver, suggest that OK432 may be of some benefit in helping to prevent hepatic metastasis, at least in part, via its activation of hepatic macrophages.

Involvement of protein kinase C in the interleukin 1 alpha-induced gene expression of matrix metalloproteinases and tissue inhibitor-1 of metalloproteinases (TIMP-1) in human uterine cervical fibroblasts

The role of protein kinase C in the interleukin 1 (IL-1)-mediated production of pro-matrix metalloproteinases (proMMPs) and tissue inhibitor-1 of metalloproteinases (TIMP-1) in human uterine cervical fibro-blasts has been investigated. IL-1 and a protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA) augmented the production of proMMP-1 (interstitial procollagenase), proMMP-3 (prostromelysin-1) and TIMP-1, but their effects were inhibited by the protein kinase C inhibitors 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) and staurosporine in a dose-dependent manner. The suppressive effect of H-7 and staurosporine on the IL-1-induced production of proMMPs-1 and -3 and TIMP-1 resulted from the decrease in the steady-state levels of their mRNAs. When protein kinase C was down-regulated by treating the cells with a high level of TPA, the inductive effect of IL-1 upon proMMP-3 production was reduced considerably. These results indicate that protein kinase C mediates the IL-1-induced production of proMMPs-1 and -3 and TIMP-1 at the pretranslational level in human uterine cervical fibroblasts. On the other hand, neither IL-1 nor TPA modulated the production of proMMP-2 (progelatinase A). Both IL-1 and TPA also accelerated the production of prostaglandin E2 (PGE2) by cervical fibroblasts. However, the treatment of the cells with staurosporine in the presence of IL-1 or TPA further augmented PGE2 synthesis, suggesting that the increased synthesis of PGE2 by IL-1 treatment is mediated via signalling pathways distinct from those of proMMPs-1 and -3 and TIMP-1.

Cytokine-induced tumor immunogenicity: endogenous interleukin-1 alpha expressed by fibrosarcoma cells confers reduced tumorigenicity

A direct correlation between the constitutive expression of IL-1 alpha and reduced tumorigenicity of fibrosarcomas was observed. This was established in fibrosarcoma cell lines which produce IL-1 alpha 'spontaneously', possibly as an aberration of oncogene-mediated transformation or upon IL-1 alpha gene transfer. In fibroblasts intracellular or membrane-associated IL-1 alpha is expressed, whereas the secreted form of the cytokine (IL-1 beta) is absent. Studies on the mechanisms of tumor regression of the IL-1 alpha-positive fibroblastoid cell lines indicated that IL-1 alpha potentiates the development of tumor cell-specific CTLs, which are of importance for tumor eradication. Thus, IL-1 alpha induces enhanced helper T cell activity which provides auxiliary signals for the growth/development of CTLs. Non-adaptive effector cells, activated locally by IL-1 alpha-expressing fibrosarcoma cells, also contribute to the eradication of IL-1 alpha-expressing fibrosarcomas. Local IL-1 alpha expression potentiated antigen presentation, by the malignant fibroblasts as well as by tissue-resident antigen-presenting cells, thus further potentiating anti-tumor immune responses. Mice, in which IL-1 alpha-producing tumors were regressed, developed an immune memory and rejected a challenge with an IL-1 non-producing violent tumor cell line. Endogenous IL-1 alpha activates a cytokine cascade (i.e., IL-6, CSF), produced by the malignant cells and possibly also by stromal cells. However, IL-1 alpha expression is essential for fibrosarcoma eradication, while other cytokines possibly amplify and sustain its action.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of interleukin-1 and interleukin-2 on mammary gland leukocyte populations and histology during the early nonlactating period

Eight Jersey cows free of intramammary infection (IMI) with major mastitis pathogens were intramammarily infused with interleukin (IL)-1, IL-2, or phosphate-buffered saline (PBS) after the last milking prior to drying off. Rectal temperatures were monitored hourly through 6 hours after infusion and at 24-hour intervals thereafter. Quarter secretions were collected 7 days prior to drying off, at drying off, and on days 1, 2, 3, 4, 7, and 14 of the nonlactating period. Cows were slaughtered and mammary tissues were collected at 7 (3 cows) and 14 (5 cows) days after treatment. The infusion of 10 micrograms of IL-1 produced an elevation in rectal temperature that was significantly higher than that of cows receiving IL-2 or PBS at 4, 5, and 6 hours after treatment, whereas cows receiving 1.0 mg of IL-2 exhibited no change in rectal temperature. Somatic cell counts (SCC) in mammary glands infused with IL-1 or IL-2 remained significantly elevated over PBS-infused control glands through day 4 after treatment. Neutrophils predominated in secretions of IL-1-treated glands, and macrophages and lymphocytes predominated in IL-2-treated glands. The mammary involution process was accelerated by IL-2, and tissues exhibited reductions in alveolar epithelial and luminal areas and increases in connective tissue stroma and degree of leukocytosis compared with IL-1 and control glands. Concentrations of plasma cells producing IgG1, IgG2, IgA, and IgM also were greatest following IL-2 infusion. Results suggest that IL-2 is superior to IL-1 in stimulating an increase in mammary mononuclear cell populations and in accelerating involution during the early nonlactating period.

The role of cytokines in heat stroke

Heat stroke is a disease characterized by high fever. Cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-delta) play a major role in fever production. In the current studies, eight patients with heat stroke were enrolled in a cytokine studies. Serum cytokine levels of these patients were determined by EIA methods, and in vitro IL-1 and IL-1 inhibitor production were determined by murine thymocyte proliferation assay and/or EIA. Significantly high levels of circulating IL-1, TNF-delta, and IL-6 were demonstrated. Positive correlations were demonstrated between the body temperature and the level of IL-1 beta, and the cooling time and level of serum IL-1 beta. In addition, monocytes from heat stroke patients after complete recovery, secreted a much higher amount of IL-1 than did normal volunteers. However, there was no difference in IL-1 inhibitor production. These results indicate that cytokines may play a major role in the pathogenesis of heat stroke, and the ability to make different amounts of IL-1 in response to exogenous stimulation appear to be risk factors for an attack of heat stroke.

In vivo anti inflammatory effects of the M20 IL-1 inhibitor: I. Effects on acute inflammatory parameters

Previous studies have described an IL-1 Inhibitor produced by a myelomonocytic line developed in our laboratory (Eur J Immunol 1986; 16: 1449). This IL-1 Inhibitor was secreted by the M20 line constitutively in addition to IL-1, from which it could be separated. We have recently shown that the M20 IL-1 Inhibitor is distinct from the IL-1ra. In vitro this factor inhibited IL-1 induced proliferative responses as well as PGE2 secretion by IL-1 induced fibroblasts. We also showed for the first time (Lymphokine Research 1988; 7(3): 268) that an IL-1 inhibitor can reduce IL-1 induced inflammatory effects. This study describes the specific effect of the M20 IL-1 Inhibitor on IL-1 induced parameters of inflammation: fever, leukocytosis and local foot pad swelling or lymph node enlargement. Purified preparations of the IL-1 Inhibitor, when injected together with IL-1, or before the IL-1, reduced fever, leukocytosis, foot pad swelling and lymph node enlargement caused by IL-1. Similar responses were obtained by injection of IL-6 or TNF, but were unaffected by the IL-1 Inhibitor, when injected together. These results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responses in vivo. The potential importance of this factor as an anti-inflammatory and immune regulatory factor, is supported by the findings of this study.

Interleukin-1 beta-induced cytosolic phospholipase A2 activity and protein synthesis is blocked by dexamethasone in rat mesangial cells

Interleukin-1 beta induces gene expression and secretion of the secretory phospholipase A2 (sPLA2) and prostaglandin E2 (PGE2) release from rat mesangial cells. We have previously shown that prolonged treatment of rat mesangial cells with interleukin-1 beta (IL-1 beta) also enhances the cytosolic phospholipase A2 (cPLA2) activity. This effect of IL-1 beta on the cPLA2 activity is inhibited by actinomycin D and cycloheximide, indicating that both transcription and translation are involved. Here, we describe that IL-1 beta increases mRNA levels and protein synthesis of cPLA2 itself. In parallel with the effect of dexamethasone on the sPLA2, this glucocorticoid inhibits the IL-1 beta-enhanced cPLA2 activity as a result of the suppression of IL-1 beta-induced cPLA2 gene expression. This report suggests that the pro-inflammatory action of interleukin-1 beta may, in part, be mediated by its effects on cPLA2 activity.

Marginal periodontitis and cytokines: a review of the literature

Recent research on the immunopathogenesis of marginal periodontitis has focused on cytokines, because these mediators govern biological activities in inflammatory tissue destruction. Several studies have been carried out to elucidate the involvement of cytokines in periodontitis, including cytokine measurements in samples from gingival tissue, gingival crevicular fluid, and in supernatants of stimulated in vitro grown cells from gingival tissue and peripheral blood. The results, summarized in this review, suggest that cytokines are involved in the progress of periodontitis. Furthermore, cytokines may be valuable as markers of tissue breakdown. At the present stage, however, there are difficulties in detecting and quantifying cytokines by immunochemical methods and, in particular, by bioassays. Increased knowledge of the cytokine network may open new pathways of periodontitis treatment by controlling processes involved in tissue breakdown.

Recombinant cytokines as immunological adjuvants

This paper describes the bacterial expression and purification of bioactive recombinant ovine interleukin-2 (rovIL-2), interleukin-1 alpha (rovIL-1 alpha) and tumour necrosis factor alpha. These purified proteins had specific activities in appropriate bioassays of 1 x 10(7) 1 x 10(7) and 1 x 10(5) U/mg, respectively. Recombinant ovIL-1 alpha was assessed as an immunological adjuvant for the sheep response to the model protein avidin. When delivered either intradermally or intramuscularly in conjunction with avidin in aluminium hydroxide the rovIL-1 alpha significantly enhanced the secondary humoral response. Doses of 1, 10 or 100 micrograms per sheep enhanced the humoral response to a similar extent. Recombinant ovIL-1 beta had similar adjuvant activity in that it was demonstrated to significantly enhance the sheep humoral response to an experimental H. contortus antigen. This increase in specific antibody, however, did not correlate with enhanced protection against infection with third stage H. contortus larvae. In addition incorporation of rovIL-1 beta into the formulation was shown not to alter the isotype profile of H. contortus antigen specific antibody.

Increased levels of tumor necrosis factor and interleukin 1 in bronchoalveolar lavage fluids from pigs infected with Mycoplasma hyopneumoniae

We examined the levels of tumor necrosis factor (TNF)-alpha and interleukin-1 (IL-1) in bronchoalveolar lavage fluids (BALF) from pigs experimentally infected with Mycoplasma hyopneumoniae using biological assays with WEHI-164 cells and D10.G4.1 cells, respectively. Increased TNF-alpha and IL-1 in BALF were found in infected pigs with gross and/or microscopic lesions. A time-course study suggested TNF-alpha and IL-1 to be persistently elevated in infected pigs. Their presence in BALF would thus appear to be associated with the development of pneumonic lesions in M. hyopneumoniae infected pigs.

Effects of cytokines on the pituitary-adrenal axis in cancer patients

Cytokines, which include interferons (IFNs), interleukins (ILs), and tumor necrosis factor (TNF), are immunoregulatory proteins produced by lymphocytes and inflammatory cells. Several cytokines, most noteworthy IFNs and ILs, stimulate glucocorticoid secretion. In this study, the effects of variable doses and repetitive administration of IFNs and TNF on secretion of pituitary hormones and cortisol were measured. Patients were given for a period of 15 days on alternating days injections of IFN-beta (IFN-beta ser), 90 or 450 x 10(6) IU, IFN-gamma, 0.1-100 x 10(6) IU, or TNF 125-275 micrograms/m2. Sixty to 120 min after IFN-beta ser injection median levels of cortisol, adrenocorticotropin (ACTH), prolactin (PRL), and growth hormone (GH) rose two-fold. Urinary free cortisol excretion increased significantly during the day following IFN-beta ser administration. IFN-gamma > or = 30 x 10(6) IU caused a comparable rise in plasma cortisol. TNF induced two- to four-fold increases in ACTH and cortisol. The fact that increased cortisol secretion was associated with a rise in the level of ACTH as well as PRL and GH suggests that the cytokines increased cortisol by stimulating the anterior pituitary. The hormonal response induced by cytokines was unrelated to their pyrogenic effect, undiminished with repetitive treatment, and not dose-dependent above a threshold level. These observations reinforce the concept of a physiologic link between the immune system and the hypothalamic-pituitary-adrenal (HPA) axis.

Species differences in [125I]interleukin-1 binding in brain, endocrine and immune tissues

There were dramatic species differences in the level of [125I]recombinant human interleukin-1 alpha ([125I]hIL-1 alpha) binding with high levels of binding present in mouse and rabbit tissues, while no specific binding was present in rat and guinea pig tissues. Utilizing [125I]hIL-1 alpha, moderate to high levels of specific binding were observed in EL-4 6.1 cells (representative of Type I IL-1 receptors) and in mouse hippocampus, spleen and testis; however, no specific [125I]hIL-1 alpha binding was present in Raji cells (representative of Type II IL-1 receptors) and in rat tissues. On the other hand, utilizing [125I]hIL-1 beta, high specific IL-1 binding was present in EL-4 6.1 and Raji cells and moderate binding was evident in mouse tissues, whereas specific [125I]hIL-1 beta binding to rat tissues was not detectable. Moreover, no IL-1 binding in rat tissues was observed using [125I]hIL-1 receptor antagonist, [125I]mouse IL-1 beta or the homologous radioligands [125I]rat IL-1 beta or [125I]rat IL-1 receptor antagonist. These data demonstrate that under optimal conditions for labeling Type I or Type II IL-1 receptors, no specific binding is observed in rat tissues suggesting the presence of novel IL-1 receptor(s) in rat tissues.

Antitumor effect of interleukin 7 in combination with local hyperthermia in mice bearing B16a melanoma cells

Interleukin (IL)-7 has been evaluated for its influence, alone or in combination with local hyperthermia (LH), on B16a melanoma-bearing mice. Six- to eight-week-old C57BL/6J male mice were inoculated s.c. with 5 x 10(5) tumor cells into the left hind limb. Mice were randomly divided into four groups, and treated s.c. with IL-7 (5 ng) or saline as control, twice a day for three weeks beginning eight days after tumor inoculation. LH, using hot water circulator at 43 +/- 0.2 degrees C for 30 min, was induced to the limb with tumor twice a week for two weeks. Size of the primary tumor was measured every other day for five weeks. Mice were sacrificed five weeks after tumor inoculation. The size of the primary tumor and the number of lung metastases were reduced in mice treated either with IL-7 or LH alone. As a control for IL-7, granulocyte colony stimulating factor (G-CSF) alone had no effect on primary tumor size or number of lung metastases. The greatest antitumor effect was observed in mice treated with IL-7 in combination with LH. Survival was prolonged significantly only in mice treated with IL-7 plus LH compared with that of mice treated with saline. Decreased natural killer (NK) cell activity, number of Thy1.2 cells, and ratio of L3T4+/Lyt2+ cells were associated with tumor growth. These parameters were restored in mice treated with IL-7 plus LH. Increases in levels of IL-1 alpha, IL-6, tumor necrosis factor (TNF alpha) and interferon (IFN gamma) were associated with an increase in the survival of tumor-bearing mice treated with IL-7 and/or LH. These results suggest that changes in T-cell, NK cell and cytokines such as IL-1 alpha, IL-6, TNF-alpha and IFN-gamma in response to IL7 and/or LH might account for prolonged survival of B16a melanoma-bearing mice and that IL-7 might be useful as a potential antitumor agent combined with other therapy in certain malignant solid tumors with metastases.

Mononuclear cell-conditioned medium enhances thrombin-stimulated PGI2 production by human umbilical vein endothelial cells in culture

We investigated the effect of blood mononuclear cell-conditioned medium on prostacyclin (PGI2) production by human umbilical vein endothelial cells in culture (HUVEC), and compared the potency of the conditioned medium in PGI2 production with that of various cytokines and lipopolysaccharide (LPS). HUVEC which had been preincubated with LPS, interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor (TNF alpha), or interferon-gamma (IFN-gamma) produced more PGI2 than control cells in response to thrombin. However, the HUVEC preincubated with the conditioned medium made with mononuclear cells with or without LPS (LPS-Mo-CM, Mo-CM) produced more PGI2 than those preincubated with LPS, IL-1 alpha, IL-1 beta, TNF alpha, or IFN-gamma. Although the concentrations or IL-1 beta and TNF alpha in the post-culture medium of HUVEC treated with LPS-Mo-CM were much higher than those with Mo-CM, LPS-Mo-CM which was made with 13,000/ml of mononuclear cells and 1 microgram/ml of LPS did not significantly augment the subsequent PGI2 production by HUVEC as compared with Mo-CM made with the same numbers of mononuclear cells. PGI2 production by Mo-CM-treated HUVEC still exceeded that of control cells, even when an excess amount of antibody to TNF alpha and/or IL-1 alpha was added to the Mo-CM. It is possible that Mo-CM contains unknown cytokines besides IL-1 and TNF which stimulate the HUVEC to produce PGI2.

Human chorionic gonadotropin induces interleukin-1 gene expression in rat Leydig cells in vivo

Luteinizing hormone (LH)/human chorionic gonadotropin (hCG) causes inflammatory-type responses in the testis. In the present study, we evaluated the effects of hCG on Leydig cell interleukin-1 (IL-1) gene expression. Using monoclonal antibody (ED2) staining for macrophages, our Leydig cell preparations had no significant contamination with macrophages. When purified Leydig cells from normal rats were cultured for 24 h and then treated with IL-1 beta (1-100 ng/ml) for 6 h, IL-1 beta induced dose-dependent increases in IL-1 beta mRNA levels. IL-1 beta also induced IL-1 alpha mRNA accumulation; however, the level of IL-1 alpha mRNA was much lower than that of IL-1 beta mRNA. When rats were treated with either saline or hCG (5 units i.p.), hCG markedly induced IL-1 beta mRNA accumulation in purified Leydig cells at 6 h which persisted for over 24 h. However, hCG had no direct effect on purified Leydig cell or crude interstitial cell IL-1 mRNA levels. Our results suggest that inflammatory effects of hCG in vivo may be mediated by increased IL-1 gene expression in Leydig cells.

Active translocation of platelets into sinusoidal and Disse spaces in the liver in response to lipopolysaccharides, interleukin-1 and tumor necrosis factor

1. Injection of lipopolysaccharides (LPS) or endotoxin into mice and rats induces a prolonged increase in serotonin (5-hydroxytryptamine: 5HT), predominantly in the liver. 2. The 5HT increase reflects the accumulation of platelets in the sinusoidal and perisinusoidal Disse spaces (spaces between endothelial cells and hepatocytes) in the liver. 3. Most of the platelets which accumulated in these spaces still retained their intact structure and a large amount of 5HT. 4. Interleukin-1 and/or tumor necrosis factor also induce the platelet response. 5. Kupffer's cells play a key role in this platelet response. 6. Anti-platelet drugs currently used, except for anti-inflammatory steroids, were ineffective in preventing the platelet response. 7. This platelet response is different from the well known platelet aggregation. 8. The possible involvement of this platelet response in insulin-independent hypoglycaemia, disseminated intravascular coagulation, septic shock, hepatitis, Shwartzman type reactions or self-defense mechanisms is discussed.

Expression and release of interleukin-1 by human glioblastoma cells in vitro and in vivo

The present study demonstrates interleukin-1 (IL-1) production by human glioblastoma cells both in vitro and in vivo. The presence of IL-1 alpha and IL-1 beta transcripts was analyzed in 4 cell lines. IL-1 alpha mRNA was expressed constitutively in one cell line whereas constitutive IL-1 beta mRNA could not be detected in any of the cell lines. IL-1 alpha transcripts could be induced with phorbol myristate acetate (PMA) or PMA plus lipopolysaccharide (LPS) in 2 of 4 cell lines and IL-1 beta mRNA in 2 of 4 cell lines. Culture fluid from these cell lines was tested for the presence of IL-1 using a specific radio-immuno-assay for either IL-1 alpha or IL-1 beta. In agreement with the results on RNA, one of 4 cell lines was found to constitutively produce IL-1 alpha but not IL-1 beta. After treatment with PMA and LPS, IL-1 alpha was detected in the culture fluid from two other lines and IL-1 beta in the medium from three lines. That the IL-1 produced by these cell lines was biologically active was confirmed in a two step thymocyte proliferation assay. IL-1 like activity was detected in all samples that were positive in the radio-immuno-assay. Finally, immunohistological analysis on fresh frozen tumour sections provided evidence for IL-1 production by glioblastoma cells in vivo. Fourteen out of 28 glioblastomas were stained with an anti-IL-1 alpha monoclonal antibody while none of them was stained with an anti-IL-1 beta antibody.

Fever: causes and consequences

The present review distinguishes pathogenic, neurogenic, and psychogenic fever, but focuses largely on pathogenic fever, the hallmark of infectious disease. The data presented show that a complex cascade of events underlies pathogenic fever, which in broad outline - and with frank disregard of contradictory data - can be described as follows. An invading microorganism releases endotoxin that stimulates macrophages to synthesize a variety of pyrogenic compounds called cytokines. Carried in blood, these cytokines reach the perivascular spaces of the organum vasculosum laminae terminalis (OVLT) and other regions near the brain where they promote the synthesis and release of prostaglandin (PGE2). This prostaglandin then penetrates the blood-brain barrier to evoke the autonomic and behavioral responses characteristic of fever. But then once expressed, fever does not continue unchecked; endogenous antipyretics likely act on the septum to limit the rise in body temperature. The present review also examines fever-resistance in neonates, the blunting of fever in the aged, and the behaviorally induced rise in body temperature following infection in ectotherms. And finally it takes up the question of whether fever enhances immune responsiveness, and through such enhancement contributes to host survival.

Regulation of hyaluronate production by interleukin 1 in cultured human chorionic cells

Human chorionic cells in culture synthesized and secreted a large amount of hyaluronate as well as tissue collagenase. When these cells were treated with human recombinant interleukin 1 alpha (hrIL-1), the biosynthesis and secretion of hyaluronate were predominantly accelerated, but those of sulfated glycosaminoglycans were not modulated. This promotive effect of hrIL-1 was not due to the increase in endogenous prostaglandins including prostaglandin E2 since cyclooxygenase inhibitors, indomethacin and diclofenac did not modulate the IL-1-mediated production of hyaluronate. On the other hand, the cotreatment of chorionic cells with hrIL-1 and cycloheximide suppressed the IL-1-mediated hyaluronate production, suggesting that protein, de novo, synthesis required for the enhancement of hyaluronate synthesis. Upon treatment with hrIL-1, the membrane bound-hyaluronate synthase activity was increased up to 5-fold in a time-dependent manner. On the other hand, when chorionic cells were treated with hrIL-1 and/or protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methyl-pyperadine hydrochloride (H7), the IL-1-mediated production of hyaluronate was effectively suppressed. Similarly, H7 effectively suppressed the protein kinase activator, 12-O-tetradecanoyl-phorbol-13-acetate-enhanced production of glycosaminoglycans with a similar extent. These results indicate that IL-1-induced acceleration of hyaluronate production was reflected on the increase in hyaluronate synthase activity, and that protein kinase C participates positively in the IL-1-signal transduction for the increased synthesis of hyaluronate in human chorionic cells.

IL-1 in gingival crevicular fluid following closed root planing and papillary flap debridement

Interleukin (IL)-1 alpha and beta are cytokines which can mediate inflammatory, bone resorbing, and reparative effects in the periodontium, but few longitudinal data exist exploring their role following periodontal therapy. This study examined gingival crevicular fluid (GCF) concentrations of IL-1 alpha and IL-1 beta at sites with shallow sulci (SS) or inflamed moderate/advanced pockets (M/AP) before and 6 months after treatment with closed scaling/root planing (SC/RP) or papillary flap debridement (PFD), all in the same subject (n = 14 patients). No significant differences were noted in IL-1 alpha or beta concentrations (determined with two-site enzyme-linked immunosorbent assays) between SS and M/AP sites at baseline. While both therapies improved clinical parameters of periodontal disease, IL-1 alpha concentration increased significantly (p < 0.05) in M/AP-PFD sites 6 months after treatment, but were unchanged in other groups. IL-1 beta concentrations were numerically lower after therapy, except for a significant increase (p < 0.05) in M/AP-PFD sites. These data suggest that surgical wound healing in an inflamed, plaque-infected site (M/AP-PFD) results in prolonged production of IL-1, which may be a reflection of the extent of tissue trauma and delayed wound healing. In spite of increased IL-1 levels, these sites demonstrated significant short-term improvement in clinical attachment level (+ 1.8 mm, p < or = 0.001) postoperatively.

Priming of human monocytes for enhanced lipopolysaccharide responses: expression of alpha interferon, interferon regulatory factors, and tumor necrosis factor

Culture of human monocytes with either granulocyte-macrophage colony-stimulating factor or gamma interferon (IFN-gamma) results in a primed state, during which these cells express heightened responses to bacterial lipopolysaccharide (LPS). The production of IFN-alpha in response to LPS by human monocytes has an absolute requirement for priming. Tumor necrosis factor (TNF) expression is also greatly enhanced in primed monocytes after LPS stimulation, but unlike IFN-alpha, TNF is readily expressed in unprimed monocytes as well. In an effort to determine the molecular events associated with IFN-alpha induction in this system, freshly isolated human monocytes were primed by culture with either IFN-gamma or granulocyte-macrophage colony-stimulating factor and then treated with LPS; expression of IFN-alpha subtype 2 (IFN-alpha 2), IFN regulatory factors (IRFs), and TNF was assessed by Northern (RNA blot) analysis. IRF-1 mRNA is expressed at high levels in monocytes and is regulated by both LPS and priming cytokines, but its expression alone does not correlate with the induction of IFN-alpha 2 expression. IRF-2 mRNA is expressed in a more gradual manner following LPS stimulation, implying a possible feedback mechanism for inhibiting IFN-alpha expression. However, nuclear run-on analysis indicates that IFN-alpha 2 is not transcriptionally modulated in this system, in striking contrast to TNF, which is clearly regulated at the transcriptional level. In addition, IFN-alpha 2 mRNA accumulation is superinduced when primed monocytes are treated with LPS plus cycloheximide, while TNF mRNA is relatively unaffected. The results demonstrate that priming can affect subsequent LPS-induced gene expression at different levels in human monocytes.

The ability of polymorphonuclear leukocytes to produce active oxygen in a model of peritonitis in rats

To elucidate the mechanism of enhancing survival in peritonitis rats treated with lentinan, a fully purified beta-1,3-glucan, we measured the active oxygen-producing ability of polymorphonuclear leukocytes (PMNs). Four groups of rats (group I, fecal peritonitis control; II, rats receiving 3 mg/kg lentinan intraperitoneally at the same time as peritonitis induction; III, rats receiving 1 mg/kg gentamicin intramuscularly; and IV, rats receiving combined lentinan-gentamicin treatment) were used. The survival period was significantly longer in group IV than in the other three groups. The ability of ascitic PMNs to produce active oxygen (superoxide, H2O2, myeloperoxidase) was significantly more than that of blood PMNs in each group at 20 h after peritonitis induction. The increase in active oxygen production in ascitic PMNs was higher in group IV compared with that in the other three groups. The concentration of lentinan in the blood was high at 24 h after administering lentinan intraperitoneally to both the normal and peritonitis rats. In the in vitro study, the superoxide production in normal rat blood PMNs was significantly higher in the presence of cytokines (IL-1 beta, IL-6, TNF-alpha) without dose-dependence but was not higher for the lentinan group than in the control. This study therefore suggests that lentinan activated the peritoneal macrophage secretory activity and produced cytokines which thus enhanced the ability of PMNs to produce active oxygen, which possesses a bactericidal ability in PMNs.

Interleukin-1 modulatory effect on the action of chemotherapeutic drugs and localized irradiation of the lip, duodenum, and tumor

PURPOSE

This study was conducted to examine the radioprotective and radiochemoprotective capabilities of interleukin 1 beta (IL-1) on two acute-reacting normal tissues of the C3H mouse, the mucosa of the lip and the duodenum. Also assessed was the modulating effect of IL-1 on tumor growth in the same strain of mice.

METHODS AND MATERIALS

IL-1 was administered to C3H/Km mice in combination with fractionated irradiation, or with cyclophosphamide, cisplatin, or 5-fluorouracil (5FU) followed by irradiation. Normal tissue damage was evaluated in the mouse lip, using a subjective scoring system for tissue reaction, and in the duodenum, using the crypt cell survival assay. RIF-1 fibrosarcoma tumor response was assayed with the regrowth delay method.

RESULTS

IL-1 protected against the acute reaction produced by fractionated irradiation in the lip mucosa, shifting the dose-response curve by 3.8 Gy. IL-1 was protective when injected intraperitoneally 24 hr before CY or c-DDP, which were given immediately before the first of five daily radiation dose fractions. The dose-response curves for cyclophosphamide and cisplatin were shifted 4.0 Gy and 1.6 Gy, respectively. IL-1 did not protect against 5FU toxicity when treatments were administered in that same sequence; however, when 5FU was given 4 or 8 hr before IL-1 and the first radiation dose fraction followed 20 or 16 hr later, there was significant protection and the curves were separated by 1.5 Gy or 3.5 Gy. IL-1 also protected duodenal crypt cells against the cytocidal effect of fractionated irradiation, with a dose difference of 1.5 Gy and an improvement of crypt survival of 11.7%. It was even more protective for these cells against the enhanced drug toxicity when cyclophosphamide or 5FU were administered immediately before the first of five daily radiation doses, with the dose differences of 4.4 and 5.3 Gy, respectively, and improvements of crypt survival of 33.8 and 29.9%, respectively. There was no modification by IL-1 of the effect of irradiation alone on the RIF-1 tumor.

CONCLUSION

This study demonstrates the potential for use of IL-1 as an auxiliary in combinations with chemotherapeutic agents and radiation. It also indicates that for some drugs, such as 5FU, IL-1 effects may be sequence dependent.

Biphasic effects of interleukin-1 alpha on dermal fibroblasts: enhancement of chemotactic responsiveness at low concentrations and of mRNA expression for collagenase at high concentrations

Fibrotic reactions in the skin are frequently preceded by infiltration of inflammatory cells and subsequent migration of fibroblastic cells. Interleukin-1 is secreted by inflammatory cells and can regulate proliferation and protein synthesis of fibroblasts. Its role in fibroblast chemotaxis has not been elucidated in any detail. Using the well-established Boyden chamber assay for measurement of chemotaxis in vitro, we studied a wide range of recombinant human interleukin-1 alpha concentrations to assess intrinsic chemotactic activity of interleukin-1 alpha and to determine the capacity of this mediator to modify the chemotactic response of fibroblasts to other chemoattractants. This was compared with the interleukin-1 alpha dose required for enhancement of mRNA expression for collagenase. Although interleukin-1 alpha was not chemoattractive for fibroblasts, it specifically augmented migration toward fibroblast-conditioned medium and toward platelet-derived growth factor but not toward epidermal growth factor, fibronectin, or transforming-growth factor-beta. Interleukin-1 alpha did not measurably alter the expression of mRNA for the platelet-derived growth factor receptor or its platelet-derived growth factor-binding characteristics. Doses required to enhance fibroblast chemotaxis were distinctly lower than those required for stimulation of collagenase mRNA expression.

Interleukin-1 beta measured by radioimmunoassay in the rat spleen and thymus is increased during chronic inflammatory stress

We have developed an extraction method and radioimmunoassay for the measurement of interleukin-1 beta (IL-1 beta) in rat tissues, using an antibody specific for IL-1 beta, IL-1 beta was detected in the spleen and thymus of control rats. Adrenalectomy (ADX) had no effect upon control levels of IL-1 beta. In animals with adjuvant-induced arthritis, IL-1 beta content in the spleen and thymus increased after 14 days. These increases in tissue IL-1 beta contents were not evident in ADX arthritic animals. We conclude that IL-1 beta synthesis is stimulated in tissues of the immune system following the development of adjuvant-induced arthritis. Failure to observe elevated levels of tissue IL-1 beta in ADX arthritic rats may be evidence for tissue depletion due to increased IL-1 beta release in the absence of circulating corticosteroids.

Sequential immunotherapy using interleukin-1 followed by interleukin-2 of ascitic MOPC104E-bearing mice

This study shows that intraperitoneal injection of interleukin-1 (IL-1), followed by interleukin-2 (IL-2), can effectively eradicate murine ascitic tumor cells. This antitumor effect of IL-1 and IL-2 was abolished when administration of IL-2 preceded that of IL-1. Solid tumors inoculated subcutaneously (s.c.) into the back of mice were also sensitive to this combined i.p. therapy, indicating a systemically-operating antitumor mechanism. Splenocytes from tumor-bearing mice treated with IL-1 followed by IL-2 showed a strong tumor-neutralizing activity. The population responsible proved to be Lyt2.2 (CD8)-positive cells.

Independent effects of interleukin 1 on proteoglycan synthesis and proteoglycan breakdown of bovine articular cartilage in vitro

We studied the effects of human recombinant interleukin-1 beta on proteoglycan metabolism of bovine articular cartilage in organ culture. IL-1 was more potent in inhibiting synthesis (IC50 4 ng/mL) than in stimulating breakdown of proteoglycans (EC50 200 ng/mL). Inhibition of proteoglycan synthesis began to plateau earlier (2 days) than stimulation of proteoglycan release (4 days). Both effects could be neutralized with a polyclonal anti-IL-1 beta antibody; however, higher antibody titers were required to block IL-1 effects on proteoglycan synthesis than to neutralize those on proteoglycan release. Chloroquine, but not hydrocortisone, blocked IL-1-mediated proteoglycan breakdown. Both drugs, however, augmented IL-1-induced inhibition of proteoglycan synthesis. Our data suggest that the effects of IL-1 on articular cartilage proteoglycan synthesis and proteoglycan breakdown can be regulated independently.

Effects of cytokines on HLA class I antigen expression on Huh6 and HB611 cells

This study investigated the expression of HLA class I antigens on Huh6 and HB611 cells induced by interferon (IFN)-alpha, IFN-gamma, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta. All of these cytokines induced the antigens on both cells in a dose-dependent manner, with IFNs inducing much more expression than TNF-alpha or IL-1 beta. We have already reported that protein kinase C (PKC) is involved in the antigen expression induced by IFN-gamma on Huh6 cells. The antigen expression induced by IFN-alpha was also blocked by a PKC inhibitor, H-7. However, the antigen expression by TNF-alpha or IL-1 beta was not inhibited by H-7, by a protein kinase A inhibitor, HA1004, nor by a calmodulin antagonist, W-7. These results suggested that PKC, Ca(2+)-calmodulin, and cAMP are not involved in the induction of HLA class I antigens on both cells by TNF-alpha and IL-1 beta. We concluded that TNF-alpha and IL-1 beta induced much less expression of HLA class I antigens on both cells than IFNs and that this might be because the signaling pathway by TNF-alpha and IL-1 beta differed from that by IFNs.

Interleukin-1 receptor antagonist inhibits calcium accumulation in in vivo chronic granuloma induced by potassium permanganate

Interleukin-1 (IL-1) is a monokine that exerts multiple biological activity, including immunity and inflammation. Moreover, IL-1 is involved in Ca2+ release causing hypercalcemia and bone resorption. Recently, a 22 kDa natural inhibitor to IL-1 called interleukin-1 receptor antagonist (IL-1ra) has been described in human fluids, which specifically binds IL-1 alpha or IL-1 beta receptors. In this study, we found that experimental granuloma induced by subcutaneous injections (0.2 ml) of potassium permanganate (KMnO4) 1:40 saturated crystal solution, after 7 days was strongly inhibited in size, weight and calcium content (measured as dry ash weight by incineration of granuloma tissue) compared with untreated controls, in mice treated intraperitoneally with IL-1ra (20 micrograms/bolus) given twice; the first at the same time of the induction of the granuloma and the second 24 hours later. In addition, leukotriene B4 and prostaglandin E2 were also inhibited in fresh granuloma of mice treated with IL-1ra. Taken together, these findings conclude for the first time, that the accumulation of calcium in chronic inflammatory states is strongly inhibited by IL-1ra, which decreases tissue calcergy and can potentially be useful for the treatment of calcium-related inflammatory diseases and malignancy-associated hypercalcemia.

Tyrosine kinase activity is involved in the protein kinase C induced expression of interleukin-1 beta gene in monocytic cells

The role of protein tyrosine kinases in the expression of interleukin-1 beta (IL-1 beta) gene in response to phorbol esters (PMA) in THP-1 cell line was investigated. Genistein, a specific tyrosine kinase inhibitor, inhibited PMA induced IL-1 beta protein and mRNA levels in THP-1 cells. Genistein did not have a significant effect on PMA induced activity in transient transfection assays using reporter gene constructs containing the PMA responsive sequence of the IL-1 beta gene linked to IL-1 beta promoter, or five repeats of PMA responsive sites (AP-1 sites) in front of a thymidine kinase promoter. This indicates that the tyrosine kinase activity required for the PMA induced IL-1 beta expression is coupled downstream from or functions independent of the PMA induced AP-1 activity.

Reduced production of immunoreactive interleukin-1 by peripheral blood monocytes of patients with acute and chronic viral hepatitis

The in vitro production of interleukin-1 beta by peripheral blood monocytes derived from patients with various liver diseases was studied. An impaired production of immunoreactive interleukin-1 (IL-1) (mean +/- SEM) by monocytes stimulated with an optimal dose (100 ng/ml) of lipopolysaccharide was observed in patients with chronic hepatitis B (N = 13; 32 +/- 6 pg/ml) or chronic hepatitis C (N = 13; 61 +/- 12 pg/ml) as compared to those of healthy control individuals (N = 35; 166 +/- 24 pg/ml; P = 0.0003 and P = 0.015, respectively), whereas an unaltered IL-1 production was seen in patients with alcoholic cirrhosis (N = 23; 125 +/- 28 pg/ml) and primary biliary cirrhosis (N = 6; 111 +/- 33 pg/ml). Similar to the situation seen in chronic viral hepatitis, lipopolysaccharide-stimulated monocytes from patients with acute hepatitis also showed a decreased IL-1 production in the first week after onset of jaundice (N = 17; 55 +/- 20 pg/ml; P = 0.001) and a return to normal in the second and third week. An impaired production of IL-1 in chronic as well as acute viral hepatitis is a further example of the known disturbed immunoregulation in this disease.

Human recombinant IL-1 receptor antagonist (IL-1Ra) inhibits leukotriene B4 generation from human monocyte suspensions stimulated by lipopolysaccharide (LPS)

The effect of human recombinant IL-1 receptor antagonist (hrIL-1Ra) on leukotriene B4 (LTB4) release was investigated in activated human monocyte cultures. To stimulate LTB4 generation, LPS was used as an agonist. Detection was performed with the highly sensitive radioimmunoassay method. The cells were treated with scalar concentrations using LPS at 1-1000 ng/ml for different periods of time. The greater LTB4 stimulation was found at LPS 100 ng/ml for 18 h incubation time. Preincubation of monocytes with cytochalasin B (CB) (5 micrograms/ml) for 15 min augmented the release of LTB4 when LPS was used. A dose-dependent inhibition was found when human monocytes were pretreated for 10 min with hrIL-1Ra at different concentrations (0.25-250 ng/ml) and then treated with LPS 100 ng/ml for 18 h. Maximum inhibition was observed at the highest concentration of hrIL-1Ra (250 ng/ml). Macrophages treated with a non-selective 5-lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA), used at 10 microM, added 15 min before LPS 100 ng/ml, produce a dose-dependent inhibition of LTB4. Cells pretreated with arachidonic acid, at various concentrations (10(-9)-10(-5) M) for 10 min and then treated with LPS 100 ng/ml for 18 h, were also inhibited in a dose-dependent manner by hrIL-1Ra in their production of LTB4. The inhibition of LTB4 release by hrIL-1Ra, in LPS-stimulated human monocytes, may suggest an important modulatory role for this new cytokine (monokine) in inflammation and immunity and may hold future therapeutic implications for diseases involving LTB4 as a mediator.

Gingival fluid IL-1 and IL-6 levels in refractory periodontitis

Selected gingival bacteria and cytokine profiles associated with patients who did not respond to conventional periodontal therapy (refractory) were evaluated. 10 subjects with a high incidence of post-active treatment clinical attachment loss (> 2% sites/year lost > or = 3 mm) were compared to 10 age-, race-, and supragingival plaque-matched patients with low post-treatment clinical attachment loss (< 0.5% sites/year) relative to the following parameters at 2 sites/patient with the deepest probing depths: (1) presence of 3 selected periodontal pathogens (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens) in subgingival plaque as determined by selective culturing, and (2) gingival crevicular fluid (GCF) levels of 3 cytokines associated with bone resorption (IL-1 alpha, IL-1 beta, IL-6) as determined by two-site ELISA. Results indicated no significant differences in any clinical measurement (except incidence of clinical attachment loss), in the presence of any bacterial pathogen, or in GCF cytokine levels between refractory subject sites versus stable subject sites. However, when sites producing the greatest total GCF cytokine/patient were compared, sites from refractory patient produced significantly more IL-6 (30.1 +/- 4.0 versus 15.4 +/- 2.8 nM, p < 0.01). The subgingival presence of each of the 3 bacterial pathogens was associated with elevated GCF IL-1 concentrations. These data suggest that gingival IL-1 and IL-6 production is different in response to local and systemic factors associated with periodontitis, and that IL-6 may play a role in the identification and mechanisms of refractory periodontitis.

Chemical carcinogens increase IL-1 alpha and IL-6 gene transcripts in human keratinocytes

Using reverse transcriptase-linked polymerase chain reaction, the effect of polycyclic aromatic hydrocarbons (PAHs) on IL-1 alpha, IL-1 beta and IL-6 gene expression in cultured human keratinocytes was studied. Exposure to beta-naphthoflavone and benz(a)anthracene resulted in a higher copy number of IL-1 alpha and IL-6 mRNA while lower level of IL-1 beta mRNA was detected in these cells. These data suggest that, like ultraviolet B (UVB) radiation, ubiquitous environmental carcinogenic PAHs are potent inducers of IL-1 alpha and IL-6 cytokines and, unlike UVB, they downregulate IL-1 beta in human keratinocytes.

Lack of effect of interleukins 1 alpha and 1 beta, during in vitro perifusion, on anterior pituitary release of adrenocorticotropic hormone and beta endorphin in the male rat

It has been demonstrated that interleukin 1 (IL1) injection provokes a great variety of biological effects, notably an activation of the corticotropic axis, increasing plasma adrenocorticotropic hormone (ACTH) and corticosterone. However, the primary site of action of IL1 is still controversial. In the present study, we first verified the in vivo capability of human interleukins 1 alpha (hIL1 alpha) and 1 beta (hIL1 beta) to release ACTH and beta endorphin (beta EP) in the normal male rat, before investigating, through an anterior pituitary (AP) perifusion system, the hIL1 alpha and hIL1 beta effects on basal and corticotropin-releasing factor (CRF)-induced ACTH and beta EP secretions. This system enabled the examination of a dynamic profile of hormones secretion, avoiding the possibility of feedback mechanisms, as is the case with the use of regular but very often longtime incubations. The results showed that in a perifusion system, with a short duration treatment (below 2 hr) compatible with the kinetics of action observed in vivo, basal and CRF-induced ACTH and beta EP release were not modified in the presence of a broad range of concentrations (from 10(-12) to 10(-9) M) of hIL1 alpha or hIL1 beta. Taken together, these results clearly show that in an in vitro situation close to physiological conditions, the primary site of action of hIL1 alpha and hIL1 beta on ACTH and beta EP release is not located at the AP level in the male rat.