Elevated IL-1beta Research Articles

Differential Vaginal Expression of Interleukin‐1 System Cytokines in the Presence of Mycoplasma hominis and Ureaplasma urealyticum in Pregnant Women

The genital mycoplasmas, Ureaplasma urealyticum and Mycoplasma hominis, are commonly identified in the vagina of healthy pregnant women. However, these microorganisms are the most common isolates from the amniotic fluids of women in preterm labor. The mechanisms responsible for vaginal colonization and ascent to the uterus remain undetermined. We evaluated the association between U. urealyticum and M. hominis vaginal colonization and the presence of pro-inflammatory and anti-inflammatory interleukin-1 system components in asymptomatic pregnant women of different ethnicities. Vaginal specimens, obtained from 224 first trimester pregnant women, were assayed for interleukin-1beta (IL-1beta) and IL-1 receptor antagonist (IL-1ra) concentrations by ELISA. U. urealyticum and M. hominis vaginal colonization were identified by polymerase chain reaction (PCR). Vaginal colonization with M. hominis was identified in 37 (16.5%) women, and was more prevalent in black (18.9%) and Hispanic (20.9%) than in white (4.2%) women (p = 0.01). U. urealyticum was present in 84 (37.5%) women and there was no ethnic disparity in its detection. M. hominis colonization was associated with elevated median vaginal IL-1beta concentrations in both black women (p = 0.02) and Hispanic women (p = 0.04), and was unrelated to vaginal IL-1ra concentrations. In marked contrast, U. urealyticum colonization was associated with elevations in vaginal IL-1ra levels, but not with IL-1beta concentrations, in black women (p = 0.02) and Hispanic women (p < 0.0001) and marginally in white women (p = 0.06). M. hominis colonization in healthy pregnant women is associated with localized pro-inflammatory immune activation, while U. urealyticum colonization is associated with immune suppression.

Associations between systemic status, periodontal status, serum cytokine levels, and delivery outcomes in pregnant women with a diagnosis of threatened premature labor.

Threatened premature labor (TPL) often results in preterm birth (PB). The aim of the present study was to evaluate the associations of periodontal and general health conditions with TPL and PB in relation to serum cytokine levels and the composition of subgingival plaque. Eighty-eight women were enrolled in the study. Systemic conditions were assessed, and subgingival plaque samples obtained for bacterial analysis. Periodontal examinations included assessments of plaque, gingivitis, clinical attachment level, probing depth, and bleeding on probing. Serum cytokine levels also were analyzed. Gestational age at delivery was recorded, and the mothers were divided into a TPL or non-TPL group, and into a non-TPL-TB (term birth), non-TPL-PB, TPL-TB, or TPL-PB group, accordingly. Forty subjects were classified as TPL and 18 as TPL-PB. There were significant differences between the TPL and non-TPL subjects in several of the systemic and periodontal parameters and serum cytokine levels. Significant differences were observed between the TPL-TB and TPL-PB groups in the percentage of Tannerella forsythensis (Tf, formerly Bacteroides forsythus), and the serum interleukin (IL)-8 and IL-1beta levels. Significant negative correlations between the gestational age at delivery and several periodontal parameters and serum IL-8 and IL-1beta levels, and significant positive correlations between periodontal status and serum IL-8 and IL-1beta levels, were observed. The TPL women revealed worsened periodontal conditions and elevated serum IL-8 and IL-1beta levels compared to the non-TPL women. The elevated levels of serum IL-8 and IL-1beta could have affected the maintenance of the proper uterine-fetus relationship, resulting in premature uterine contractions.

Inducible cytokine gene expression in the brain in the ME7/CV mouse model of scrapie is highly restricted, is at a strikingly low level relative to the degree of gliosis and occurs only late in disease

The temporal course of cerebral cytokine gene expression was investigated in the ME7/CV murine scrapie model to determine any association with neuropathological events. Analysis by RNase protection assay (RPA) demonstrated no transcripts for ILs 2, 3, 4, 5, 6, 7, 10, 12p40 and 13, granulocyte macrophage colony-stimulating factor, IFN-gamma or lymphotoxin-alpha at any time during the course of this disease. Transcripts for transforming growth factor-beta 1 were constitutively expressed in both control and scrapie-infected brain and were elevated at terminal disease. RPA and quantitative real-time RT-PCR detected low levels of transcripts for IL-1 alpha, IL-1 beta and TNF alpha in scrapie-infected brain but only IL-1 beta was elevated consistently in all mice studied. Although glial cell activation within the hippocampus was evident from 100 days post-infection (p.i.), elevated IL-1 beta transcripts (and immunoreactivity) were evident from 180 days p.i., around the time of hippocampal pyramidal neuron loss, and increased steadily thereafter to reach a 3.5-fold increase at terminal disease. Even at their maximum, levels of these transcripts were disproportionately low relative to the degree of glial cell activation. It is concluded that cytokine gene expression in the ME7 scrapie-infected mouse brain, relative to the degree of reactive gliosis, is highly restricted, temporally late and disproportionately low.

Interleukin-1beta elevation during the postpartum period.

During the postpartum period, women frequently report increased fatigue, which, if severe, may interfere with maternal-child bonding, delay a new mother's return to her activities of daily living, and contribute to depression. Several studies have sought to determine psychosocial contributions to fatigue during the postpartum period, but few evaluate any physiological changes that may contribute to fatigue during this time. The following study was designed to test whether the potent, pro-inflammatory cytokine interleukin-1beta (IL-1beta), known to be a physiological mediator of fatigue in several clinical and experimental conditions, is elevated in women during the postpartum period and whether it might be related to symptoms of fatigue. Levels of fatigue and the urinary excretion of IL-1beta were measured in 26 women over 4 weeks postpartum. Correlations between fatigue and activation of the inflammatory response were investigated. Results demonstrated a significant elevation in IL-1beta during the postpartum period compared to control participants (p < .05) and a significant, although delayed, correlation between IL-1beta elevation and fatigue (p < .05). These results suggest that activation of the inflammatory response, as reflected by elevation in urinary IL-1beta, occurs in association with postpartum fatigue. Studies to explore further this association and to identify specific mechanisms of action are needed.

High serum tumor necrosis factor-alpha levels are associated with lack of response to infliximab in fistulizing Crohn's disease.

Infliximab, a chimeric monoclonal antibody directed against tumor necrosis factor-alpha (anti-TNF-alpha), has been effective in the treatment of patients with active Crohn's disease and with fistulas. We investigated the effect of infliximab on circulating cytokines and acute phase proteins in patients with fistulas to determine the clinical response to anti-TNF-alpha. A total of 36 patients with fistulizing Crohn's disease were selected for study. Serum from patients was drawn before the infusion on day 0 and at wk 2, 4, 6, 8, and 10 after completion of treatment. Circulating concentrations of TNF-alpha, interleukin-1beta (IL-1beta), and IL-6 were measured by ELISA. The functional activity of circulating TNF-alpha was assessed by the WEHI 164 TNF-alpha bioassay. Acute phase proteins were also determined. Elevated TNF-alpha, IL-1beta, IL-6, and acute phase proteins were observed in patients with Crohn's disease. Of the patients with fistulas, 22 (61.1%) responded to treatment. Before receiving infliximab, higher levels of serum TNF-alpha were found in patients who did not respond to infliximab compared with those who did (median interquartile range 26, 0-245 pg/ml; n = 14 vs 0, 0-22 pg/ml, n = 22). Patients showed no change in circulating levels of TNF-alpha during the course of the study. This treatment produces a clinical improvement in about two-thirds of CD patients with fistulas. The circulating levels of TNF-alpha are associated with the response to infliximab and could help to identify patients who would benefit from anti-TNF-alpha treatment.

Local levels of interleukin-1beta, -4, -6 and tumor necrosis factor alpha in an experimental model of murine osteomyelitis due to staphylococcus aureus.

The purpose of this study is to evaluate local levels of interleukin-1 beta (IL-1 beta), -4 (IL-4), -6 (IL-6), and tumour necrosis factor-alpha (TNF-alpha), in a model of murine osteomyelitis due to Staphylococcus aureus. Cytokine levels in supernatants derived from bone homogenates were determined by enzyme-linked immunosorbent assay, for 28 days following the direct implantation of murine tibiae with S.aureus. Levels of IL-1 beta and IL-6 in infected bone were elevated in the early post-infection period and then decreased. In contrast, TNF-alpha levels remained elevated 3 to 28 days post-infection, while IL-4 levels were elevated late in the course of infection. The histopathology of infected bone showed predominant infiltration of inflammatory cells and bone resorption 3 to 7 days after infection, and bone resorption and adjacent areas of formation 14 to 28 days after infection. These results suggest that the elevated IL-1 beta and IL-6 levels induced by infection may be related to bone damage mainly in the early phase of infection, and that TNF-alpha and IL-4 may at least in part be associated with histopathological changes, including both bone resorption and formation in the later phase of this osteomyelitis model.

Morphological alterations and elevations in tumor necrosis factor-alpha, interleukin (IL)-1alpha, and IL-6 in mixed glia cultures following exposure to trimethyltin: modulation by proinflammatory cytokine recombinant proteins and neutralizing antibodies.

Trimethyltin (TMT), is a hippocampal neurotoxicant characterized by neuronal degeneration, astrogliosis, and microglia reactivity with an associated elevation in proinflammatory cytokine mRNA levels. To examine the role of proinflammatory cytokines in the TMT-induced glia response, mixed cortical glia cultures were exposed to TMT and morphological and cytokine responses were examined. Morphological changes in the glia monolayer, enlarged, rounded cell bodies and retraction of the monolayer into distinct GFAP+ dense processes, displayed a dose (1, 5, and 10 microM TMT) and temporal response (6-48 h), accompanied by clustering of OX-42+ microglia. Tumor necrosis factor-alpha (TNF), interleukin (IL)-1alpha, and IL-6 mRNA levels were elevated by 3 and 6 h of TMT (10 microM) and proteins by 24 h. Recombinant proteins for IL-1alpha (100 pg/ml) and IL-6 (10 ng/ml) exacerbated the morphological response to TMT while those for TNFalpha (150 pg/ml) did not. Neutralizing antibodies (1:100) to IL-1alpha and IL-6 showed a slight decrease in the severity of the morphological response to TMT while, at 24 h, TNFalpha antibodies (1:100) and an antibody cocktail offered a significant level of protection. At 6 h, the neutralizing antibodies to TNFalpha or IL-1alpha did not elevate basal cytokine mRNA levels, however, IL-6 and the cocktail of antibodies significantly elevated IL-1alpha, IL-1beta, and IL-6 mRNA levels. The specific elevation in IL-1alpha and IL-6 mRNA levels induced by TMT remained evident only in cells coexposed to anti-TNFalpha. Similar responses in cytokine mRNA levels were seen in cocultures of hippocampal neurons and glia exposed to TMT. These data suggest a relationship between microglia activation, proinflammatory cytokine release, and glia morphological responses, the significance of which remains to be determined, as well as, the impact on neuronal degeneration.

Inhibiting adenosine deaminase modulates the systemic inflammatory response syndrome in endotoxemia and sepsis.

By pharmacological manipulation of endogenous adenosine, using chemically distinct methods, we tested the hypothesis that endogenous adenosine tempers proinflammatory cytokine responses and oxyradical-mediated tissue damage during endotoxemia and sepsis. Rats were pretreated with varying doses of pentostatin (PNT; adenosine deaminase inhibitor) or 8-sulfophenyltheophylline (8-SPT; adenosine receptor antagonist) and then received either E. coli endotoxin (lipopolysaccharide; 0.01 or 2.0 mg/kg) or a slurry of cecal matter in 5% dextrose in water (200 mg/kg). Resultant levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-10 were measured in serum and in liver and spleen. Untreated, 2 mg/kg lipopolysaccharide elevated serum TNF-alpha, IL-1beta, and IL-10. PNT dose dependently attenuated, without ablating, the elevation in serum TNF-alpha and IL-1beta and raised liver and spleen IL-10. PNT also attenuated elevation of TNF-alpha in serum, liver, and spleen at 4 and 24 h after sepsis induction, and 8-SPT resulted in higher proinflammatory cytokines. Modulating endogenous adenosine was also effective in exacerbated (8-SPT) or diminished (PNT) tissue peroxidation. Survival from sepsis was also improved when PNT was used as a posttreatment. These data indicate that endogenous adenosine is an important modulatory component of systemic inflammatory response syndromes. These data also indicate that inhibition of adenosine deaminase may be a novel and viable therapeutic approach to managing the systemic inflammatory response syndrome without ablating important physiological functions.

Elevated interleukin-1beta in pericardial fluid of patients with ischemic heart disease.

Inflammatory cytokines may play an important role in the pathogenesis of atherosclerosis and heart failure. We have previously demonstrated that long-term treatment with interleukin (IL)-1beta in the coronary artery and myocardium promotes coronary arteriosclerosis and impairs cardiac function, respectively. The cytokines in pericardial fluid may reflect the extent of coronary atherosclerosis and may also directly promote the atherosclerotic process. This study was designed to examine the significance of cytokine concentrations in pericardial fluid of patients with cardiovascular disease. We measured concentrations of 10 major cytokines in the pericardial fluid of 56 consecutive patients obtained during open heart surgery, 27 with ischemic heart disease (IHD group), 21 with valvular heart disease (VHD group) and eight with congenital heart disease (CHD group). The pericardial concentrations of IL-1beta (pg/ml) were significantly higher in the IHD group (60 +/- 15) than in the VHD (29 +/- 5) or the CHD group (26 +/- 4) (P < 0.05 both). There was no significant difference in pericardial concentrations of other cytokines among the three groups. In the IHD group, the IL-1beta concentrations were significantly elevated in patients who had undergone emergency operations or in those with unstable angina. These results suggest that pericardial concentrations of IL-1beta may reflect the extent of ischemic heart disease and that elevated IL-1beta concentrations in pericardial fluid may also directly promote the process of coronary atherosclerosis.

Bradykinin receptor antagonists type 2 attenuate the inflammatory changes in peptidoglycan-induced acute arthritis in the Lewis rat.

We studied the ability of bradykinin (BK) receptor antagonists type 1 and 2 (B1-RA, B2-RA) to prevent acute inflammation. A peptidoglycan-polysaccharide (PG-APS)-induced model of arthritis in the Lewis rat was analyzed. Four groups of animals were studied for 5 days. Treatment was administered subcutaneously (s.c.) 1 mg/kg every 12 h. Group I received PG-APS and was treated with the B2-RA, CP-0597 (DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-NChg-Arg). Group II received PG-APS and was treated with a combined B1 and B2-RA, B9430 (DArg-Arg-Pro-Hyp-Gly-Igl-Ser-Dlgl-Oic-Arg). Group III received PG-APS and albumin control. Group IV received albumin control. Joint diameter, liver weight, hematocrit, white blood count and plasma concentrations of prekallikrein, high molecular weight kininogen, HK and IL-beta were measured. Groups were compared by ANOVA. Acute arthritis and hepatomegaly were attenuated in the B2-RA-treated animals (p<0.05). Weight loss was more pronounced in the B1/B2-RA-treated animals. Anemia induced by PG-APS was prevented by B2-RA and B1/B2-RA treatment (p<0.001). A marked decrease in plasma HK to 64% of normal was found in the disease-untreated animals, which was completely normalized by B2-RA treatment and partially attenuated by the B1/B2-RA (78%). The decrease in plasma prekallikrein levels was prevented by combined B1/B2-RA treatment (p<0.05). Finally, elevated plasma IL-1beta levels were lowered by B1/B2-RA treatment and were below detection limits with the B2-RA treatment. These results indicate that the systemic inflammation is due in part to BK generation which can be blocked by B2-RA, while inhibiting the B1 receptor prevents an anti-inflammatory response.

Raised levels of plasma interleukin‐1β in major and postviral depression

Interleukin-1beta (IL-1beta) is released as part of the acute phase immune response and can directly stimulate the release of corticotrophin-releasing hormone and thus induce hypothalamic pituitary adrenal axis hyperactivity. Major depression has been shown to be accompanied by both an acute phase immune response, including raised IL-1beta production and hypothalamic pituitary adrenal axis hyperactivity. In this study the possible role of IL-1beta in major depression and postviral depression was investigated. Plasma IL-1beta levels were measured in four groups; patients suffering from postviral depression (n= 17), patients with major depression (n = 20), subjects who were postviral and euthymic (n= 12) and normal controls (n = 20). IL-1beta serum concentrations were significantly elevated in both groups of depressed patients compared to controls. The serum concentrations of IL-1beta were higher in the postviral group than in the major depression group; this difference was not significant. These data confirm previous suggestions of elevated IL-1beta levels in major depression and postviral depression. IL-1beta is known to induce depressive symptoms as well as sickness behaviour and may contribute to the hypothalamic pituitary adrenal axis hyperactivity found in mood disorders.

Gut mucosal secretion of interleukin 1beta and interleukin-8 predicts relapse in clinically inactive Crohn's disease.

Trials of maintenance therapy in Crohn's disease are often underpowered, and there is need for objective markers of relapse. We assessed the relationship of whole gut lavage fluid cytokines to relapse in inactive Crohn's disease. Fifty-four patients with inactive Crohn's disease were prospectively assessed. Inactivity was determined as a Crohn's disease activity index of <150 and whole gut lavage fluid immunoglobulin G <10 microg/ml. All patients underwent whole gut lavage with analysis of IL-1beta and IL-8. Follow up was for one year. Patients with elevated whole gut lavage fluid IL-1beta (P < 0.004) and IL-8 (P < 0.02) had greater chance of relapse. Young age, short disease duration, and fistulating disease also relapsed more frequently. Multiple regression identified IL-1beta as an independent variable. In conclusion, an elevated whole gut lavage fluid IL-1beta in inactive Crohn's disease identifies patients at high risk of relapse.

Reciprocal Regulation of the Junctional Proteins Claudin-1 and Connexin43 by Interleukin-1β in Primary Human Fetal Astrocytes

Vertebrate tissues use multiple junctional types to establish and maintain tissue architecture, including gap junctions for cytoplasmic connectivity and tight junctions (TJs) for paracellular and/or cell polarity barriers. The integral membrane proteins of gap junctions are connexins, whereas TJs are a complex between occludin and members of a recently characterized multigene family, the claudins. In normal brain, astrocytes are coupled by gap junctions composed primarily of connexin43 (Cx43), whereas TJs have not been detected in these cells. We now show that treatment of primary human astrocytes with the cytokine interleukin-1beta (IL-1beta) causes rapid induction of claudin-1, with an expression pattern reciprocal to loss of Cx43. Treatment also led to protracted downregulation of occludin but no change in expression of zonula occludens proteins ZO-1 and -2. Immunofluorescence staining localized claudin-1 to cell membranes in IL-1beta-treated astrocytes, whereas freeze-fracture replicas showed strand-like arrays of intramembranous particles in treated cells resembling rudimentary TJ assemblies. We conclude that in human astrocytes, IL-1beta regulates expression of the claudin multigene family and that gap and tight junction proteins are inversely regulated by this proinflammatory cytokine. We suggest that in pathological conditions of the human CNS, elevated IL-1beta expression fundamentally alters astrocyte-to-astrocyte connectivity.

Cyclo-oxygenase-2 inhibitors ameliorate the severity of experimental colitis in rats.

Both in experimental colitis and in inflammatory bowel disease, colonic eicosanoid generation is enhanced and may contribute to the pathogenesis of the inflammatory response. To evaluate the effect of selective cyclo-oxygenase-2 (COX-2) inhibitors on the extent and severity of two models of experimental colitis. Colitis was induced by intra-caecal administration of 2 ml 5% acetic acid or intra-colonic administration of 0.1 ml 3% iodoacetamide. Rats were treated intra-gastrically with nimesulide 2 x 10 mg/kg/day, or once with SC-236 6 mg/kg, and killed 1 or 3 days after damage induction. The colon was isolated, weighed, macroscopic damage was measured, and mucosal samples were obtained for histology and for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and eicosanoid generation. The serum levels of thromboxane B2 (TXB2), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were determined. Nimesulide significantly decreased the extent of colitis induced by acetic acid. Both nimesulide and SC-236 significantly decreased the extent of iodoacetamide-induced colonic damage. The decrease in the extent of colitis induced by nimesulide was accompanied by a significant decrease in mucosal MPO and NOS activities. Nimesulide and SC-236 decreased the enhanced colonic eicosanoid generation in acetic acid and iodoacetamide-induced colitis, and, in iodoacetamide-treated rats, nimesulide also decreased the elevated serum TNF-alpha and IL-1beta levels. The effective nimesulide and SC-236-induced amelioration of the severity of the colitis in acetic acid and iodoacetamide-treated rats confirms the role of eicosanoids in their pathogenesis and suggests that COX-2 inhibitors may be of value in the treatment of inflammatory bowel disease.

Immunopathologic responses to non-lethal sepsis.

Although sepsis causes significant morbidity and mortality, its basic pathology is still not well understood. We investigated the inflammatory and physiologic alterations of non-lethal sepsis using cecal ligation and puncture (CLP), a model that induces peritonitis due to mixed intestinal flora, reproducing the complex immunology of sepsis. Groups of mice were subjected to CLP (25G needle) or sham surgery, had minimitters implanted to continuously monitor temperature and activity, and were sacrificed daily for 6 days. There was significant hypothermia (6-13 hrs post-surgery), and decreases in activity (to day 4) and weight (to day 3) but no mortality in the CLP group. Blood analyses of the CLP-treated mice showed reduced hemoglobin, platelets, lymphocytes, monocytes, and neutrophils, compared to sham animals. Both groups had nearly equivalent neutrophil influx into the peritoneum. Plasma and peritoneal G-CSF, IL-6, as well as the murine chemokines KC and MIP2-alpha were significantly higher in the CLP-treated mice at day 1. Plasma and peritoneal TNF were low (<70 pg/mL). While there was elevated IL-1beta in the peritoneum of the CLP-treated mice, this cytokine was not detected in the plasma in either treatment group. Cytokines were not detected in the pulmonary airspace of the CLP-treated mice and PMNs were not recruited to this site. Our data shows altered immunopathology in non-lethal sepsis with significant blood and cytokine alterations. Since there was 100% survival, the inflammatory response was appropriate and probably even protective.

Immune responses to osteoarticular allografts of the knee--cytokine studies.

Immunological behaviour in correlation with bone allograft survival was studied in peripheral blood and synovial fluid from seven patients who had undergone large bone resection and allograft transplantation of the knee. Plasma and synovial fluid samples for cytokine measurements [interleukin (IL-1beta, IL-6) and tumour necrosis factor alpha (TNF-alpha)] were drawn from peripheral blood for diagnostic arthrocentesis. Two patients were monitored using consecutive sampling up to 12 months postoperatively. Graft survival was considered excellent, but local or diffuse resorption and also fatigue fractures were seen. These findings show that soluble products of T-cell, macrophage and osteoblast origin, produced as a response to the bone-graft antigens, might be responsible for the bone resorption seen in our material. The elevated IL-1beta and TNF-alpha levels detected support this statement.

Chronic idiopathic neutropenia of adults is associated with decreased bone mineral density and alterations in bone turnover biochemical markers.

The aim of this study was to assess bone mineral density (BMD) and biochemical indices of bone metabolism in patients with chronic idiopathic neutropenia of adults (CINA) and define the relationships, if any, between these parameters and serum levels of interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha), two cytokines normally involved in bone metabolism. Femoral neck BMD, serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and type I procollagen carboxy-terminal propeptide (PICP), as well as urine-free deoxypyridoline (Dpd) cross-links, N-telopeptide (NTx) and C-telopeptide (CTx) cross-links of type I of collagen were measured in 45 CINA patients and 36 normal subjects. Patients were arbitrarily classified in two groups, A and B, as having mild (neutrophils 1700-2500/microl) or 'pronounced' (neutrophils<1700/microl) neutropenia, respectively. BMD values were found significantly reduced in both groups of patients, compared to controls, and they strongly correlated with the number of circulating neutrophils. Serum OC and urinary NTx were significantly increased in patients of group B. Both serum OC and urinary NTx correlated inversely with the number of circulating neutrophils. Serum BAP and PICP and urine Dpd and CTx were within normal range. Serum IL-1beta and TNF-alpha were elevated in both groups of patients and correlated inversely with the number of circulating neutrophils and the values of BMD. In addition, TNF-alpha, but not IL-1beta, inversely correlated with OC and NTx. These findings indicate that CINA patients have biochemical evidence of increased bone turnover which leads to decreased BMD. The elevated serum IL-1beta and TNF-alpha concentrations, suggestive of an underlying chronic inflammatory process in these patients, may be part of a mechanism accelerating bone turnover which, if prolonged, causes lowering of BMD.

DISCORDANT PULMONARY PROINFLAMMATORY CYTOKINE EXPRESSION DURING ACUTE HYPEROXIA IN THE NEWBORN RABBIT

Newborn animals are resistant to oxygen toxicity. To investigate this phenomenon, the proinflammatory cytokines interleukin (IL)-1beta, IL-8, and monocyte chemoattractant protein-1 (MCP-1) were measured during newborn rabbit hyperoxic lung injury. Pups were exposed to 95 > % O2 for 8-9 days, followed by 60% O2 until 36 days of age. Lung lavage fluid, RNA, and tissue sections were collected at 0, 2, 4, 6, 8, 10, 12, 14, 22, and 36 days. Acute inflammation occurred by 6 - 10 days of hyperoxia, and fibrosis by 22 days. Northern hybridization of lung homogenates from hyperoxia - exposed pups showed elevated MCP-1 and IL-8 mRNA expression at 6 and 10 days, respectively, compared to age - matched, air - exposed controls. Lavage fluid IL-8 protein also peaked at 10 days, and was strongly correlated to neutrophil numbers in lavage. In situ hybridization revealed elevated IL-1beta mRNA in macrophages, alveolar epithelial and interstitial cells at 2-10days, elevated MCP-1 mRNA in similar cell types at 4-8 days, and elevated IL-8 mRNA in these cells and neutrophils at 4-10 days. IL-1beta and IL-8 expression peaked during peak inflammation, whereas peak MCP-1 expression preceded macrophage influx. Comparing newborn and adult animals' chemokine responses may help explain their differences in hyperoxia susceptibility.

Enteroaggregative Escherichia coli produce intestinal inflammation and growth impairment and cause interleukin-8 release from intestinal epithelial cells.

Enteroaggregative E. coli (EAggEC) are emerging as an important cause of persistent diarrhea, especially in children in the developing world, yet the pathogenesis of EAggEC infection is poorly understood. In an ongoing prospective study of childhood diarrhea in an urban Brazilian slum, EAggEC are the leading cause of persistent diarrhea. Children from this study with EAggEC and persistent diarrhea had significant elevations in fecal lactoferrin, interleukin (IL)-8, and IL-1beta. Moreover, children with EAggEC without diarrhea had elevated fecal lactoferrin and IL-1beta concentrations. The children with EAggEC in their stool had significant growth impairment after their positive culture, regardless of the presence or absence of diarrhea. Finally, 2 EAggEC strains were shown to cause IL-8 release from Caco-2 cells, apparently via a novel heat-stable, high-molecular-weight protein. These findings suggest that EAggEC may contribute to childhood malnutrition, trigger intestinal inflammation in vivo, and induce IL-8 secretion in vitro.

Serum levels of interleukin-1 beta, luteinizing hormone, and prolactin correlate with the expression of CD45 isoforms on CD4+ peripheral blood T lymphocytes in healthy women.

The expected association between age and the CD45 isoforms expression on CD4+ T-PBL is much more obvious in men than in women. We investigated whether or not circulating factors influence the differentiation of CD4+ T-PBL. Peripheral blood samples were obtained from 56 healthy age-matched subjects (28 men and 28 women, 21-55 years old). Mononuclear leukocytes were analyzed by three-color flow cytometry. The serum concentrations of interleukin-1 beta (IL-1 beta), interleukin-6, tumor necrosis factor-alpha (TNF-alpha), GM colony-stimulating factor, prolactin (Prl), and luteinizing hormone (LH) were determined by ELISA. The expected age-related decrease of naive (CD45RA+,RO-) cells and increase of memory (CD45RA-,RO+) cells among CD4+ T-PBL were observed in men only (p < 0.001 and 0.005). In women, these correlations were not significant. On the other hand, in women only, elevated IL-1 beta was associated with fewer naive and more memory cells among CD4+ T-PBL (p < 0.001). In both sexes, IL-1 beta correlated with the expression of CD25 on CD4+ T-PBL (on either naive or memory cells, p < 0.001). Other cytokines or the CD8+ T-PBL showed no significant correlation. In women, the elevation of LH at mid-cycle inversely correlated with the proportion of naive CD4+ T-PBL (p < 0.01). Elevated LH was associated with more CD25 on memory CD4+ T-PBL (p < 0.01). A significant correlation exists between IL-1 beta and LH (p < 0.001). Furthermore, in both sexes, Prl correlated with the proportion of CD4+ cells among T-PBL. In men, elevated Prl was associated with more naive CD4+ T-PBL (p < 0.005), while in women, Prl correlated with more transient CD45RA+, RO+ cells among CD4+ T-PBL and increased TNF-alpha (p < 0.05 for both). Thus, circulating IL-1 beta could be involved in the expression of CD25 on CD4+ T-PBL and favors the generation of memory CD4+ T-PBL. In women, the IL-1 beta- and/or mid-cycle-dependent processes seem to overwhelm the age-related changes. Elevated Prl might exert a dual influence: it favors the development of naive CD4+ T lymphocytes and possibly acts in, synergy with other cytokines during immune stimulation.