Structure and function of interleukin-1 beta converting enzyme

Evaluation of the modulatory effects of Piper guineense leaves and seeds on egg albumin-induced inflammation in experimental rat models

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation processes are implicated in many degenerative diseases. Piper guineense, a West African spice belonging to the Piperaceae family has been reported to contain anti-inflammatory agents.

AIM OF STUDY

This study determined the modulatory effects of methanolic extracts of Piper guineense leaves and seeds on egg albumin-induced inflammation in rats.

STUDY DESIGN AND METHODS

Inflammation in the hind paw was induced by injecting 0.1ml egg albumin subcutaneously. Treatments including diclofenac were given orally. Rectal temperature and paw size were monitored hourly for the first 3 h' post-induction of inflammation and then at the 6th and 24th hour. Serum levels of CRP, MDA, LDH and GGT activities were determined at these hours.

RESULTS

Results showed that egg albumin-induced inflammation caused a significant (p < 0.05) increase in paw size and rectal temperature. It further showed that treatment with the leaves and seed extracts reversed the effect of inflammation on serum levels of CRP and MDA, and on LDH and GGT activities similar to diclofenac in rats.

CONCLUSION

Extracts of the Piper guineense seed and leaves have potentials of being used as an anti-inflammatory agent but further studies need to be done to determine their toxicity and effects on immunological markers of inflammation.

Differences of plasma IL-1 and TNF-α in healthy Chinese Population

Pleiotropic proinflammatory cytokines, interleukin- 1 (IL-1) and tumor necrosis factor-α (TNF-α), involved in the regulations of various immune responses, inflammatory processes and hematopoiesis. In the present study, the expression levels of IL-1 and TNF-α were detected by enzyme-linked immunosorbent assay (ELISA). Following the cytokine blockade as a successful clinical therapy for autoimmune diseases such as rheumatoid arthritis, the patients are more susceptible to a variety of opportunistic infections. IL-1 and TNF-α may be useful predictive biomarkers of diseases and offer potential targets for therapeutic intervention of inflammatory diseases. However, our results showed that the plasma IL-1 level was significantly higher in women compared to men (69.5 ± 19.8 pg/ml in men and 80.1 ± 19.5 pg/ml in women, respectively); the plasma levels of TNF-α were higher in men than women (20.8 ± 4.9 pg/ml and 18.7 ± 7.1 pg/ml, respectively). The significant gender difference of plasma interleukin-1 (IL-1) and TNF-α levels present in healthy adults in Jiangsu Province, China (P=0.002 and P=0.015, respectively), and may be as a hint for sex differences of susceptibility to many diseases and elementary immune response.

Cyr61 participates in the pathogenesis of rheumatoid arthritis by promoting proIL-1β production by fibroblast-like synoviocytes through an AKT-dependent NF-κB signaling pathway

IL-1β plays a major role in the development of rheumatoid arthritis (RA). We previously showed that Cyr61 participates in RA pathogenesis as a proinflammatory factor. Here, we found that the levels of IL-1β and Cyr61 were higher in RA SF than in osteoarthritis (OA) SF. IL-1β mRNA and proIL-1β protein levels were remarkably increased in Cyr61-stimulated FLS; however, IL-1β was hardly detectable in the supernatant. We also found that the level of adenosine triphosphate (ATP) in SF and ST was significantly increased in RA patients and that the level of IL-1β in supernatants from Cyr61-activated FLS increased significantly when we added exogenous ATP to the culture. Mechanistically, Cyr61 induced proIL-1β production in FLS via the AKT-dependent NF-κB signaling pathway, and ATP caused Cyr61-induced proIL-1β to generate IL-1β in a caspase-1-dependent manner. Our results reveal a novel role of Cyr61 in RA that involves the promotion of proIL-1β production in FLS.

Lung inflammatory response syndrome after cardiac-operations and treatment of lornoxicam

The majority of patients survive after extracorporeal circulation without any clinically apparent deleterious effects. However, disturbances exist in various degrees sometimes, which indicate the harmful effects of cardiopulmonary bypass (CPB) in the body. Several factors during extracorporeal circulation either mechanical dependent (exposure of blood to non-biological area) or mechanical independent (surgical wounds, ischemia and reperfusion, alteration in body temperature, release of endotoxins) have been shown to trigger the inflammatory reaction of the body. The complement activation, the release of cytokines, the leukocyte activation and accumulation as well as the production of several "mediators" such as oxygen free radicals, metabolites of arachidonic acid, platelet activating factors (PAF), nitric acid, and endothelin. The investigation continues today on the three metabolites of lornoxicam (the hydroxylated metabolite and two other metabolites of unknown chemical composition) to search for potential new pharmacological properties and activities.

Characterization of three pro-inflammatory cytokines, TNFα1, TNFα2 and IL-1β, in cage-reared Atlantic bluefin tuna Thunnus thynnus

Atlantic bluefin tuna (BFT) (Thunnus thynnus) is of great economic significance for world aquaculture and therefore it is necessary to ensure optimal and sustainable conditions for the farming of this species. Intensive culture of fish may be limited by infectious diseases that can impact on growth performance and cause heavy losses. However, to date there are no reports of cloning and expression analysis of any major immune genes of Atlantic BFT although some immune genes are known in other BFT species. Therefore the aim of this study was to characterize the first cytokine molecules in Atlantic BFT, through: 1) Isolation of full-length cDNA and gene sequences of TNFα1, TNFα2 and IL-1β, 2) comparison of these molecules to known sequences in other vertebrates, especially teleost fish, by multiple sequence alignment, phylogenetic tree analysis and homology modeling; 3) Quantification of in vivo expression of these cytokines in selected tissues in reared BFT over the duration of the farming process. The results indicated that these three cytokines could have value for monitoring Atlantic BFT health status. Curiously, the liver seemed to be an important site of cytokine production during poor health conditions in this species, perhaps reflecting its role as an important organ involved in fish defenses.

Upregulation of interleukin-1 by Epstein-Barr virus latent membrane protein 1 and its possible role in nasopharyngeal carcinoma cell growth

BACKGROUND

Nasopharyngeal carcinoma (NPC) is associated with Epstein-Barr virus (EBV) infection. We previously found that interleukin (IL)-1alpha and IL-1beta significantly increased in NPC tissues. This study investigated what EBV-encoded proteins were involved in such IL-1 production.

METHODS AND RESULTS

IL-1alpha and IL-1beta messenger ribonucleic acids (mRNAs) were detected in the EBV latent membrane protein 1 (LMP1) transfectant (LMP135) only by reverse transcriptase-polymerase chain reaction (RT-PCR). LMP1-mediated IL-1alpha and IL-1beta production could be enhanced by tumor necrosis factor alpha (TNF-alpha), determined by enzyme-linked immunosorbent assay (ELISA). Moreover, IL-1alpha and IL-1beta mRNAs and proteins were increased in a dose-dependent manner in epithelial cells transiently transfected by an LMP1 plasmid. Besides, immortalized human epidermal keratinocyte (RHEK-1) epithelial cells could be enhanced to proliferate by IL-1alpha and IL-1beta determined by water-soluble tetrazolium salt (WST-1) assay.

CONCLUSIONS

EBV LMP1 is capable of upregulating IL-1alpha and IL-1beta secretions from epithelial cells and positively modulated by TNF-alpha. This may consequently contribute to tumor growth in patients with NPC.

Photodynamic therapy-mediated modulation of inflammatory cytokine production by Epstein-Barr virus-infected nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a malignant disease associated with Epstein-Barr virus (EBV) infection. This study aims to examine the effects of EBV infection on the production of proinflammatory cytokines in NPC cells after the Zn-BC-AM photodynamic therapy (PDT) treatment. Cells were treated with the photosensitiser Zn-BC-AM for 24 h before light irradiation. Quantitative ELISA was used to evaluate the production of cytokines. Under the same experimental condition, HK-1-EBV cells produced a higher basal level of IL-1alpha (1561 pg/ml), IL-1beta (16.6 pg/ml) and IL-8 (422.9 pg/ml) than the HK-1 cells. At the light dose of 0.25-0.5 J/cm(2), Zn-BC-AM PDT-treated HK-1-EBV cells were found to produce a higher level of IL-1alpha and IL-1beta than the HK-1 cells. The production of IL-1beta appeared to be mediated via the IL-1beta-converting enzyme (ICE)-independent pathway. In contrast, the production of angiogenic IL-8 was downregulated in both HK-1 and HK-1-EBV cells after Zn-BC-AM PDT. Our results suggest that Zn-BC-AM PDT might indirectly reduce tumour growth through the modulation of cytokine production.

The roles of IL-17A in inflammatory immune responses and host defense against pathogens

T-helper 17 (Th17) cells are a newly discovered CD4(+) helper T-cell subset that produces interleukin-17A (IL-17A) and IL-17F. IL-17A plays important roles in allergic responses such as delayed-type hypersensitivity, contact hypersensitivity, and allergic airway inflammation. IL-17A promotes inflammation by inducing various proinflammatory cytokines and chemokines, recruiting neutrophils, enhancing antibody production, and activating T cells. IL-17A expression is also augmented in autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. Using mouse models of these diseases, we found that IL-17A plays a central role in their development. IL-6 is required for the development of Th17 cells and tumor necrosis factor functions downstream of IL-17A during the effector phase. IL-1 is important both for developing Th17 cells and eliciting inflammation. Th17 cells, like Th1 and Th2 cells, are involved in host defense against infections, but the contribution of these Th subsets to defense mechanisms differs among pathogens. The roles of IL-17F remain largely unknown. In this review, we introduce how IL-17A/IL-17F are involved in inflammatory immune responses and host defense mechanisms and discuss their relationship with other cytokines in the development of inflammatory and infectious diseases.

Evidence of the involvement of caspase-1 under physiologic and pathologic cellular stress during human pregnancy: a link between the inflammasome and parturition

OBJECTIVE

Caspase-1 is a component of the NALP3 inflammasome, a cytosolic multiprotein complex that mediates the processing of pro-inflammatory caspases and cytokines. The inflammasome represents the first line of defense against cellular stress and is a crucial component of innate immunity. Caspase-1 is the enzyme responsible for the cleavage and activation of interleukin (IL)-1 beta, which is a potent pro-inflammatory cytokine, and plays a central role in the mechanisms leading to labor (preterm and term) particularly in the context of intrauterine infection/inflammation. In addition, caspase-1 cleaves IL-18 and IL-33. The objectives of this study were to determine whether there is a relationship between amniotic fluid concentrations of caspase-1 and gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI).

STUDY DESIGN

A cross-sectional study was conducted including 143 pregnant women in the following groups: (1) mid-trimester of pregnancy (n = 18); (2) term not in labor (n = 25); (3) term in labor (n = 28); (4) preterm labor (PTL) who delivered at term (n = 23); (5) PTL without IAI who delivered preterm (n = 32); (6) PTL with IAI who delivered preterm neonates (n = 17). Caspase-1 concentrations in amniotic fluid were determined by a specific and sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) Caspase-1 was detected in amniotic fluid of women at term, but in none of the mid-trimester samples. (2) Patients in labor at term had a significantly higher median amniotic fluid concentration of caspase-1 than women at term not in labor (term in labor: 10.5 pg/mL, range 0.0-666.0 vs. term not in labor: 5.99 pg/mL, range 0.0-237.4; p < 0.05). (3) Among patients with spontaneous PTL, those with IAI (median 41.4 pg/mL, range 0.0-515.0) had a significantly higher median amniotic fluid caspase-1 concentration than those without IAI who delivered preterm (median 0.0 pg/mL, range 0.0-78.4) and than those who delivered at term (median 0.0 pg/mL, range 0.0-199.5); p < 0.001 for both comparisons.

CONCLUSIONS

(1) The presence and concentration of caspase-1 in the amniotic fluid varies as a function of gestational age. (2) Women with spontaneous labor at term had a higher median caspase-1 amniotic fluid concentration than women at term without labor. This suggests that the inflammasome may be activated in spontaneous parturition at term. Since most women with labor do not have intra-amniotic infection, we propose that cellular stress during labor accounts for activation of the inflammasome. (3) Preterm labor associated with infection/inflammation was also associated with a high concentration of caspase-1, suggesting that infection may induce caspase-1 production and activation of the inflammasome. (4) The sequential activation of the inflammasome and caspase-1, leading to interleukin-1 beta processing and secretion, is a candidate pathway leading to the activation of the common pathway of parturition.

The effect of interleukin-1 receptor antagonist on arteries and cholesterol metabolism

This review summarizes both the structure and function of IL-1 receptor antagonist (IL-1Ra), and relates our new findings, particularly those obtained in IL-1Ra-deficient mice (IL-1Ra(-/-)), to the role of IL-1Ra in arterial diseases and cholesterol metabolism. IL-1Ra(-/-) mice show an increase in neointima-formation after arterial injury. Heterozygosity in the IL-1Ra gene against the apolipoprotein E-deficient background revealed a role for IL-1 in promoting atherogenic cell signaling and that the larger lesions of IL-1Ra(-/-) mice are enriched in macrophages and depleted of smooth muscle cells. Furthermore, IL-1Ra(-/-) mice developed severe fatty livers and hypercholesteroremia following 20 weeks on a atherogenic diet compared to WT mice. Taken together, these results suggest that IL-1Ra plays important roles in restenosis after angioplasty, the development of atherosclerosis, and the metabolism of cholesterol in vivo.

Combined interleukin-6 and interleukin-1 deficiency causes obesity in young mice

Proinflammatory cytokines including interleukin (IL)-1 and IL-6 exert pleiotropic effects on the neuro-immuno-endocrine system. Previously, we showed that IL-1 receptor antagonist-deficient (IL-1Ra(-/-)) mice show a lean phenotype due to an abnormal lipid metabolism. On the contrary, it was reported that IL-6(-/-) mice exhibit obesity after 6 months of age. This study sought to assess the roles of IL-1 and IL-6 in body weight homeostasis. We generated mice deficient in IL-6 and IL-1Ra (IL-6(-/-) IL-1Ra(-/-)) and IL-6, IL-1alpha, and IL-1beta (IL-6(-/-) IL-1(-/-)). IL-6(-/-) IL-1Ra(-/-) mice exhibited a lean phenotype, similar to IL-1Ra(-/-) mice. On the other hand, IL-6(-/-) IL-1(-/-) mice became obese as early as 10 weeks of age, while IL-1(-/-) mice and IL-6(-/-) mice were normal at this age. The daily food intake was significantly higher in IL-6(-/-) IL-1(-/-) mice than in IL-6(-/-) IL-1(+/-) mice, while energy expenditure was comparable in these two strains. Acute anorexia induced by peripheral administration of IL-1 was significantly suppressed in IL-6(-/-) IL-1(-/-) mice, but not in IL-1(-/-) mice or IL-6(-/-) mice compared with wild-type mice. These results indicate that IL-1 and IL-6 are both involved in the regulation of body fat in a redundant manner in young mice.

Serial monitoring of interleukin-1?, soluble interleukin-2 receptor and lipopolysaccharide binding protein levels after death

We prospectively monitored the postmortem course of interleukin-1beta (IL-1beta), soluble interleukin-2 receptor (sIL-2R) and lipopolysaccharide binding protein (LBP) in septic and non-septic fatalities to evaluate their potential as biochemical postmortem markers of sepsis. Serum concentrations were determined by chemiluminescent immunometric assays. In both the sepsis group and the control group a postmortem increase of IL-1beta levels with the progression of time after death was observed, in both groups mainly starting from the reference concentration of healthy individuals (5 pg/ml) and with no significant differences at later time points postmortem. SIL-2R (reference limit 1,000 U/ml) was highly elevated in all individuals included in the sepsis group at all time points postmortem with statistically significant differences between the sepsis and control groups (p<0.01). An excessive postmortem decrease of sIL-2R serum levels associated with progression of time after death was observed in all cases included in the sepsis group in contrast to just 1 out of 16 control cases. LBP (reference limit <10 g/ml) was elevated in all sepsis cases whereas in the control group LBP levels were below 10 microg/ml in 88%. The postmortem time course of LBP serum concentrations showed a continuous increase in both the sepsis and control groups. We conclude that sIL-2R and LBP seem to represent appropriate diagnostic tools for the postmortem diagnosis of sepsis in forensic autopsy practice. sIL-2R serum levels above 1,000 U/ml and LBP serum levels above 10 microg/ml in peripheral venous blood obtained in the early postmortem interval can be regarded as diagnostic hints for an underlying septic condition in a deceased person.

Gene deletion of either interleukin-1beta, interleukin-1beta-converting enzyme, inducible nitric oxide synthase, or stromelysin 1 accelerates the development of knee osteoarthritis in mice after surgical transection of the medial collateral ligament and partial medial meniscectomy

OBJECTIVE

To investigate the development of osteoarthritis (OA) after transection of the medial collateral ligament and partial medial meniscectomy in mice in which genes encoding either interleukin-1beta (IL-1beta), IL-1beta-converting enzyme (ICE), stromelysin 1, or inducible nitric oxide synthase (iNOS) were deleted.

METHODS

Sectioning of the medial collateral ligament and partial medial meniscectomy were performed on right knee joints of wild-type and knockout mice. Left joints served as unoperated controls. Serial histologic sections were obtained from throughout the whole joint of both knees 4 days or 1, 2, 3, or 4 weeks after surgery. Sections were graded for OA lesions on a scale of 0-6 and were assessed for breakdown of tibial cartilage matrix proteoglycan (aggrecan) and type II collagen by matrix metalloproteinases (MMPs) and aggrecanases with immunohistochemistry studies using anti-VDIPEN, anti-NITEGE, and Col2-3/4C(short) neoepitope antibodies. Proteoglycan depletion was assessed by Alcian blue staining and chondrocyte cell death, with the TUNEL technique.

RESULTS

All knockout mice showed accelerated development of OA lesions in the medial tibial cartilage after surgery, compared with wild-type mice. ICE-, iNOS-, and particularly IL-1beta-knockout mice developed OA lesions in the lateral cartilage of unoperated limbs. Development of focal histopathologic lesions was accompanied by increased levels of MMP-, aggrecanase-, and collagenase-generated cleavage neoepitopes in areas around lesions, while nonlesional areas showed no change in immunostaining. Extensive cell death was also detected by TUNEL staining in focal areas around lesions.

CONCLUSION

We postulate that deletion of each of these genes, which encode molecules capable of producing degenerative changes in cartilage, leads to changes in the homeostatic controls regulating the balance between anabolism and catabolism, favoring accelerated cartilage degeneration. These observations suggest that these genes may play important regulatory roles in maintaining normal homeostasis in articular cartilage matrix turnover.

Caspase inhibitors as anti-inflammatory and antiapoptotic agents

The striking efficacy of Z-VAD-fmk in the various animal models presented above may reflect its ability to inhibit multiple enzymes including caspases. In accord with this, more selective, reversible inhibitors usually show low efficacy in multifactorial models such as ischaemia, but may offer some protection against NMDA-induced excitotoxicity and hepatitis. Importantly, caspase inhibitors may exhibit significant activity in vivo even when they are applied post insult. As far as the CNS is concerned, the first systemically active inhibitors have emerged. Functional recovery could be achieved in some ischaemia models, but long-term protection by caspase inhibitors is still being questioned. Recent developments in drug design enabled the first caspase inhibitors to enter the clinic. Although initially directed towards peripheral indications such as rheumatoid arthritis, caspase inhibitors will no doubt eventually be used to target CNS disorders. For this purpose the peptidic character of current inhibitors will have to be further reduced. Small molecule, nonpeptidic caspase inhibitors, which have appeared recently, indicate that this goal can be accomplished. Unfortunately, many fundamental questions still remain to be addressed. In particular, the necessary spectrum of inhibitory activity required to achieve the desired effect needs to be determined. There is also a safety aspect associated with prolonged administration. Therefore, the next therapeutic areas for broader-range caspase inhibitors are likely to involve acute treatment. Recent results with synergistic effects between MK-801 and caspase inhibitors in ischaemia suggest that caspase inhibitors may need to be used in conjunction with other drugs. It can be expected that, in the near future, research on caspases and their inhibitors will remain a rapidly developing area of biology and medicinal chemistry. More time, however, may be needed for the first caspase inhibitors to appear on the market.

Evolution of interleukin-1beta

All jawed vertebrates possess a complex immune system, which is capable of anticipatory and innate immune responses. Jawless vertebrates possess an equally complex immune system but with no evidence of an anticipatory immune response. From these findings it has been speculated that the initiation and regulation of the immune system within vertebrates will be equally complex, although very little has been done to look at the evolution of cytokine genes, despite well-known biological activities within vertebrates. In recent years, cytokines, which have been well characterised within mammals, have begun to be cloned and sequenced within non-mammalian vertebrates, with the number of cytokine sequences available from primitive vertebrates growing rapidly. The identification of cytokines, which are mammalian homologues, will give a better insight into where immune system communicators arose and may also reveal molecules, which are unique to certain organisms. Work has focussed on interleukin-1 (IL-1), a major mediator of inflammation which initiates and/or increases a wide variety of non-structural, function associated genes that are characteristically expressed during inflammation. Other than mammalian IL-1beta sequences there are now full cDNA sequences and genomic organisations available from bird, amphibian, bony fish and cartilaginous fish, with many of these genes having been obtained using an homology cloning approach. This review considers how the IL-1beta gene has changed through vertebrate evolution and whether its role and regulation are conserved within selected non-mammalian vertebrates.

IL-1 enhances T cell-dependent antibody production through induction of CD40 ligand and OX40 on T cells

IL-1 is a proinflammatory cytokine that plays pleiotropic roles in host defense mechanisms. We investigated the role of IL-1 in the humoral immune response using gene-targeted mice. Ab production against SRBC was significantly reduced in IL-1alpha/beta-deficient (IL-1(-/-)) mice and enhanced in IL-1R antagonist(-/-) mice. The intrinsic functions of T, B, and APCs were normal in IL-1(-/-) mice. However, we showed that IL-1(-/-) APCs did not fully activate DO11.10 T cells, while IL-1R antagonist (-/-) APCs enhanced the reaction, indicating that IL-1 promotes T cell priming through T-APC interaction. The function of IL-1 was CD28-CD80/CD86 independent. We found that CD40 ligand and OX40 expression on T cells was affected by the mutation, and the reduced Ag-specific B cell response in IL-1(-/-) mice was recovered by the treatment with agonistic anti-CD40 mAb both in vitro and in vivo. These observations indicate that IL-1 enhances T cell-dependent Ab production by augmenting CD40 ligand and OX40 expression on T cells.

Cloning and sequencing of feline and canine ice-related cDNAs encoding hybrid caspase-1/caspase-13-like propeptides

Caspases are cysteine proteases which have important roles in the activation of cytokines and in apoptosis. The ICE subfamily of caspases comprise peptides closely related to caspase-1, or interleukin-1beta (IL-1beta) converting enzyme (ICE), which promotes maturation of interleukin IL-1beta and interleukin-18 (IL-18) by proteolytic cleavage of precursor forms to generate biologically active peptides. Other members of this subfamily include caspase-4, -5, -13 and isoforms of these proteins. We report the cloning and sequencing of two feline and canine ICE-related cDNAs amplified by RT-PCR. The predicted proteins are 410 and 404 amino acids in length respectively and are most closely related to caspase-1 sequences across the N-terminal 115 amino acids and to human caspase-13 across the C-terminal sequence.

Nucleotide sequence of equine caspase-1 cDNA

Caspases are a family of cysteine proteases which have important roles in activation of cytokines and in apoptosis. Caspase-1, or interleukin-1 beta converting enzyme (ICE), promotes maturation of interleukin-1 beta (IL-1 beta) and interleukin-18 (IL-18) by proteolytic cleavage of precursor forms to generate biologically active peptides. We report the cloning and sequencing of equine caspase-1 cDNA. Equine caspase-1 is 405 amino acids in length and has 72% and 63% identity to human and mouse caspase-1, respectively, at the amino acid level. Sites of proteolytic cleavage and catalytic activity as identified in human caspase-1, are conserved.

Intradermal transfer of caspase-1 (CASP1) DNA into mouse dissects: role of CASP1 in interleukin-1beta associated skin inflammation and apoptotic cell death

Caspase-1 (CASP1) interleukin-1beta (IL-1beta) converting enzyme (ICE) has been cloned as a specific enzyme which activates the biologically inactive pro-form of IL-1beta into biological active IL-1beta. Based on the significant homology to Ced-3, Caenorhabditis elegans apoptotic gene and, proof of apoptotic activity of ICE in rat fibroblasts, ICE was renamed as CASP1. In contrast to in vitro functions, the in vivo significance of high expression of CASP1 in skin remains to be elucidated. We transferred plasmid DNA encoding murine CASP1 with beta-actin promoter into mouse skin. The CASP1 DNA-injected skin, but not skin injected with control plasmid without CASP1, developed localized erythema with subcutaneous nodules. The nodules were associated with marked inflammatory infiltrates. The apoptotic cells detected by the TUNEL method were distributed in and around the inflammatory foci. The plasma IL-1beta level of CASP1 DNA-injected mouse was elevated compared with that of the control DNA-injected mouse. These inflammatory reactions of CASP1 DNA-injected skin were suppressed by treatment with neutralizing anti-murine IL-1beta antibodies, but the TUNEL positive apoptotic cells were still detected. This study clearly demonstrate dual roles of CASP1 in causing IL-1beta associated granulomatous skin infiltration and inducing apoptotic cell death in vivo.

An association between LSIL and the high secretor phenotype of IL-1beta

OBJECTIVE

The aims of this study were to determine the frequency of a nucleotide transition from C to T, which leads to increased transcription of interleukin-1beta (IL-1beta) in patients with different grades of cervical lesions, and to determine whether a correlation exists between the genotypes and cervical lesions.

METHODS

One hundred forty-seven DNA samples from patients with different grades of cervical lesions were compared with 100 healthy, age and sex-matched bone marrow donors. TaqI restriction digest of PCR products was used to analyze the IL-1beta +5887 C --> T mutation and the results were confirmed using induced heteroduplex analysis with an induced heteroduplex generator.

RESULTS

The Pearson chi2 test (Yate's correction) was used for statistical analysis. Patients with LSIL (n = 80) demonstrated a high frequency of allele T, previously associated with high IL-1beta secretor phenotype, compared to controls (P = 0.000012). A trend was also observed in patients with HSIL (n = 28, P = 0.039).

CONCLUSIONS

We report for the first time a highly significant association between high secretor IL-1beta phenotypes (i.e., IL-1beta +5887 CT or TT genotypes) and LSIL. A less significant association exists with HSIL. The intrinsic ability to produce variable amounts of IL-1beta during different clinical stages involving cervical lesions may be of immunological importance in their pathogenesis.

The combined inactivation of tumor necrosis factor and interleukin-6 prevents induction of the major acute phase proteins by endotoxin

The constellation of changes known as the acute phase response (APR) is a cytokine-driven process initiated by tissue inflammation. The proinflammatory cytokines, TNF, IL-1 and IL-6, are considered to be the primary mediators of the APR. IL-6 and IL-1beta gene-deleted mice (Fattori et al., J. Exp. Med. 1994. 180: 1243-1250; Kopf et al., Nature 1994. 368: 339-342; Fantuzzi et al., J. Immunol. 1996. 157: 291-296, respectively), exhibit impaired APR to turpentine injection but only a slight reduction in plasma acute phase protein levels in response to lipopolysaccharide (LPS). This infers an important role for TNF in the LPS-induced APR, however, in the present study, normal APR to both turpentine and LPS were observed in TNF/LTalpha-deficient mice. A striking absence of elevated major acute phase proteins, SAP and SAA, was observed in mice deficient in TNF/LTalpha and IL-6, suggesting that TNF-alpha or LTalpha do indeed exert important nonredundant synergism in the IL-1/IL-6 primary response. The regulation of other parameters typically altered in an APR, body weight, blood glucose and haptoglobin, was normal in LPS-dosed TNF/LTalpha-deficient and wild-type mice. The observed transcriptional response for SAA and SAP in these TNF/LTalpha/IL-6-deficient mice, in lieu of elevated plasma levels, suggests that SAA and SAP expression is possibly posttranscriptionally regulated.

Immune-endocrine interactions in the mammalian adrenal gland: facts and hypotheses

Several cytokines, which are the major mediators of the inflammatory responses, are well-known to stimulate the hypothalamopituitary corticotropin-releasing hormone (CRH)/adrenocorticotropic hormone (ACTH) system, thereby evoking secretory responses by the adrenal cortex. Many of these cytokines, including interleukin-1 (IL-1), IL-2, IL-6, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (INF-gamma) are synthesized in the adrenal gland by both parenchymal cells and resident macrophages, and the release of some of them (e.g., IL-6 and TNF-alpha) is regulated by the main agonists of steroid hormone secretion (e.g., ACTH and angiotensin-II) and bacterial endotoxins. Adrenocortical and adrenomedullary cells are provided with specific receptors for IL-1, IL-2, and IL-6. IL-1 and TNF-alpha directly inhibit aldosterone secretion of zona glomerulosa cells, whereas IL-6 enhances it. IL-2, IL-3, IL-6, and INF-alpha are able to directly stimulate glucocorticoid production by zona fasciculata and zona reticularis cells, whereas IL-1 exerts an analogous effect through an indirect mechanism involving the stimulation of catecholamine release by chromaffin cells and/or the activation of the intramedullary CRH/ACTH system; again, TNF-alpha depresses glucocorticoid synthesis. IL-6 raises androgen secretion by inner adrenocortical layers. IL-1 enhances the proliferation of adrenocortical cells, and findings suggest that cytokines may control the apoptotic deletion of senescent zona reticularis cells. The relevance of the intraadrenal cytokine system in the fine-tuning of the secretion and growth of the adrenal cortex under normal conditions remains to be explored. However, indirect proof is available that local immune-endocrine interactions may play an important role in modulating adrenal responses to inflammatory and immune challenges and stresses.