OBJECTIVE

A growing body of literature supports the role of angiogenesis in the development and spread of a variety of human cancers including prostate cancer (Pca). Angiogenesis is controlled by chemical signals known as angiogenic factors (AF) however, little is known about angiogenesis factors in prostate cancer. We evaluated the in situ and in vitro expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, in archival prostate cancer specimens and prostate cancer cell cultures during unstimulated and cytokine stimulated conditions.

METHODS

Ex-vivo studies involved immunohistochemical analysis for VEGF expression and distribution in 25 archival specimens including, prostate cancer, benign prostatic hyperplasia (BPH) and normal prostate tissue. In-vitro studies utilized prostate cancer cells (DU-145) grown in culture and stimulated with cytokines thought to induce VEGF (i.e. IL-1 alpha, IL-1 beta, TNF-alpha and TNF-beta). Cell culture supernatants were analyzed by ELISA for VEGF levels.

RESULTS

Immunohistochemical studies demonstrated that in 20 of 25 specimens prostate cancers cells stained positively for VEGF. BPH and normal prostate cells displayed little staining for VEGF. DU-145 prostate cancer cells produced low levels of VEGF in unstimulated conditions. Induction of DU-145 cells with cytokines resulted in differential stimulation whereby TNF was a potent inducer of VEGF, and IL-1 produced lesser but statistically significant increases in VEGF expression.

CONCLUSIONS

Our immunohistochemical results indicate that significant levels of VEGF are present in prostate cancer, but not in BPH or normal prostate cells in-vivo. In-vitro studies suggest that differential regulation of angiogenesis factor expression by IL-1 and TNF occurs in prostate cancer. Identifying the angiogenesis factors involved in prostate cancer growth and understanding their regulation will lead to the development of anti-angiogenic strategies useful for diagnostic studies and therapeutic interventions.

Cytokines have been implicated in the pathogenesis of gram-negative bacterial meningitis. The effects of pentoxifylline and dexamethasone on the release of tumor necrosis factor (TNF), interleukin (<em>IL</em>)-1, and <em>IL</em>-6 from primary murine microglial cell cultures were explored using bioassays. When added concomitantly with lipopolysaccharide, pentoxifylline blocked the release of TNF and <em>IL</em>-1 but not <em>IL</em>-6, while dexamethasone inhibited the release of TNF and <em>IL</em>-6. After a 2-h exposure of microglia to lipopolysaccharide, pentoxifylline but not dexamethasone still inhibited the release of TNF. Release of TNF was enhanced <em>20</em>-fold by priming of the microglia with interferon-gamma; only pentoxifylline blocked the priming effect of interferon-gamma on TNF release. These results demonstrate that pentoxifylline and dexamethasone differentially regulate the release of cytokines in microglial cell cultures and provide potential insight into their role in the treatment of gram-negative bacterial meningitis.

Human airway smooth muscle (HASM) cells express interleukin (<em>IL</em>)-13 and <em>IL</em>-4 receptors and respond to these cytokines with signal transducer and activator of transcription-6 and extracellular signal-regulated kinase (ERK) activation. The purpose of this study was to determine whether <em>IL</em>-13 and/or <em>IL</em>-4 influence eotaxin release in HASM cells and whether the ERK mitogen-activated protein (MAP) kinase pathway is involved in these events. Eotaxin release into HASM cell supernatants was assayed by ELISA, and eotaxin mRNA expression was determined by Northern blot analysis. Pretreatment with either <em>IL</em>-13 or <em>IL</em>-4 resulted in a concentration- and time-dependent release of eotaxin, although <em>IL</em>-4 was more effective. Eotaxin release was approximately twice baseline after treatment with 50 ng/ml <em>IL</em>-13 or <em>IL</em>-4 (P < 0.001). <em>IL</em>-13 and <em>IL</em>-4 also acted synergistically with tumor necrosis factor (TNF)-alpha to induce eotaxin release: TNF-alpha alone (10 ng/ml for 24 h) resulted in an approximately fourfold increase in eotaxin release, whereas TNF-alpha in combination with <em>IL</em>-13 or <em>IL</em>-4 resulted in 10- or <em>20</em>-fold increases (P < 0.05). Similar results were obtained for eotaxin mRNA expression. Pretreatment with either U-0126 (10 microM) or PD-98059 (30 microM), both inhibitors of MAP/ERK kinase, the enzyme upstream of ERK, inhibited <em>IL</em>-13- or <em>IL</em>-4-induced eotaxin release (P < 0.05). U-0126 also inhibited <em>IL</em>-13, and TNF-alpha induced mRNA expression. Our results indicate that <em>IL</em>-13 and <em>IL</em>-4 cause eotaxin release in HASM cells through a mechanism that, in part, involves ERK activation and suggest that the smooth muscle may be an important source of chemokines leading to eosinophil recruitment in asthma.

The rat hepatoma cell line Fao was used to study the role of three inflammatory mediators on the mRNA regulation of several acute-phase proteins. In the presence of 10(-6) M dexamethasone beta-fibrinogen mRNA levels increased 6-fold after addition of recombinant human <em>IL</em> 6 (rh<em>IL</em> 6). rh<em>IL</em> 1 beta or recombinant human tumor necrosis factor alpha (rhTNF alpha) had essentially no effect on beta-fibrinogen mRNA induction but led to a <em>20</em>-fold increase in alpha 1-acid glycoprotein mRNA in the presence of dexamethasone. On the other hand, rh<em>IL</em> 6 was a much weaker stimulator of alpha 1-acid glycoprotein mRNA synthesis. All three mediators reduced albumin mRNA concentrations to about 30% of controls. Whereas the induction of beta-fibrinogen mRNA was potentiated by dexamethasone, the synthetic glucocorticoid analog was an absolute requirement for the stimulation of alpha 1-acid glycoprotein mRNA. The mRNA levels of the negative acute-phase protein albumin were induced 5-fold by dexamethasone alone. The beta-fibrinogen mRNA induction started immediately after addition of rh<em>IL</em> 6 and reached a maximum between 12 and 18 h. In contrast, the time-course for alpha 1-acid glycoprotein mRNA synthesis showed a lag phase of 8 h followed by an increase up to <em>20</em> h after rh<em>IL</em> 1 beta. rhTNF alpha led to an even more delayed increase in alpha 1-acid glycoprotein mRNA. Whereas in the case of beta-fibrinogen mRNA induction no synergistic effect was observed between various concentrations of the three mediators, the combination of rh<em>IL</em> 6/rh<em>IL</em> 1 beta as well as rh<em>IL</em> 6/rhTNF alpha or rh<em>IL</em> 1 beta/rhTNF alpha regulated synergistically alpha 1-acid glycoprotein and albumin mRNA. It is concluded that discrete acute-phase proteins are regulated differently by the inflammatory mediators <em>IL</em> 6, <em>IL</em> 1 beta and TNF alpha, indicating that the acute-phase response is more complex than previously assumed. The Fao cell line used in this study turned out to be an ideal model for acute-phase protein regulation, suitable for the discrimination between the inflammatory mediators <em>IL</em> 6 and <em>IL</em> 1/TNF alpha.

OBJECTIVE

To examine the possibility that interleukin-6 (IL-6) can act as a paracrine regulator in adipose tissue by examining effects on adipogenic genes and measuring interstitial IL-6 concentrations in situ.

METHODS

Circulating and interstitial IL-6 concentrations in abdominal and femoral adipose tissue were measured using the calibrated microdialysis technique in 20 healthy male subjects. The effects of adipose cell enlargement on gene expression and IL-6 secretion were examined, as well as the effect of IL-6 in vitro on gene expression of adiponectin and other markers of adipocyte differentiation.

RESULTS

The IL-6 concentration in the interstitial fluid was approximately 100-fold higher than that in plasma, suggesting that IL-6 may be a paracrine regulator of adipose tissue. This was further supported by the finding that adding IL-6 in vitro at similar concentrations down-regulated the expression of adiponectin, aP2, and PPARgamma-2 in cultured human adipose tissue. In addition, gene expression and release of IL-6, both in vivo and in vitro, correlated with adipose cell size.

CONCLUSIONS

These data suggest that IL-6 may be a paracrine regulator of adipose tissue. Furthermore, increased adipose tissue production of IL-6 after hypertrophic enlargement of the adipose cells may detrimentally affect systemic insulin action by inducing adipose tissue dysfunction with impaired differentiation of the pre-adipocytes and/or adipocytes and lower adiponectin.

BACKGROUND

Both anaphylactic food allergy and eosinophil-associated gastrointestinal disorders are associated with T(H)2 responses and food-specific IgE, yet they have very different clinical presentations.

OBJECTIVE

To determine whether the clinical differences between anaphylactic food allergy and eosinophil-associated gastrointestinal disorders are reflected in different T(H)2 responses to foods.

METHODS

Subjects with peanut allergy (PA), subjects with allergic eosinophilic gastroenteritis (AEG), and nonatopic subjects were enrolled. Antigen-specific IL-4, IL-5, IFN-gamma, and TNF T-cell responses to peanut, soy, and shrimp were measured by using intracellular cytokine staining and polychromatic flow cytometry.

RESULTS

Two distinct subpopulations of T(H)2 cells were found: IL-5+ T(H)2 (IL-4+, IL-5+) and IL-5(-) T(H)2 (IL-4+, IL-5(-)) cells. Peanut-specific IL-5+ T(H)2 cells were present at a 20-fold greater frequency in AEG versus PA (81 vs 4 per 10(6) CD4 cells; P = .05), whereas there were similar frequencies of IL-5(-) T(H)2 cells (67 vs 41 per 10(6)). For all foods, IL-5+ T(H)2 cells accounted for a significantly greater fraction of the antigen-specific cells in AEG relative to PA (29% vs 4%; P < .0001). In PA but not AEG, IL-5(-) T(H)2 responses to peanut were highly correlated with peanut-specific IgE (r = 0.87 vs 0.55, respectively). All subject groups elicited similar very low-magnitude T(H)1 responses to food antigens.

CONCLUSIONS

T(H)2 responses are composed of 2 subpopulations: IL-5+ T(H)2 and IL-5(-) T(H)2 cells. IL-5+ T(H)2 food allergen-specific T cells are singularly associated with AEG, whereas PA is associated with a dominant IL-5(-) T(H)2 response. These results suggest heterogeneity within the T(H)2 cytokine response, with different T(H)2 responses alternatively favoring IgE-mediated or eosinophil-dominant immunopathology.

<em>IL</em>-15 and <em>IL</em>-2 are two structurally and functionally related cytokines whose high affinity receptors share the <em>IL</em>-2R beta-chain and gamma-chain in association with <em>IL</em>-15R alpha-chain (<em>IL</em>-15R alpha) or <em>IL</em>-2R alpha-chain, respectively. Whereas <em>IL</em>-2 action seems restricted to the adaptative T cells, <em>IL</em>-15 appears to be crucial for the function of the innate immune responses, and the pleiotropic expression of <em>IL</em>-15 and <em>IL</em>-15R alpha hints at a much broader role for the <em>IL</em>-15 system in multiple cell types and tissues. In this report, using a highly sensitive radioimmunoassay, we show the existence of a soluble form of human <em>IL</em>-15R alpha (s<em>IL</em>-15R alpha) that arises from proteolytic shedding of the membrane-anchored receptor. This soluble receptor is spontaneously released from <em>IL</em>-15R alpha-expressing human cell lines as well as from <em>IL</em>-15R alpha transfected COS-7 cells. This release is strongly induced by PMA and ionomycin, and to a lesser extent by <em>IL</em>-1 beta and TNF-alpha. The size of s<em>IL</em>-15R alpha (42 kDa), together with the analysis of deletion mutants in the ectodomain of <em>IL</em>-15R alpha, indicates the existence of cleavage sites that are proximal to the plasma membrane. Whereas shedding induced by PMA was abrogated by the synthetic matrix metalloproteinases inhibitor GM6001, the spontaneous shedding was not, indicating the occurrence of at least two distinct proteolytic mechanisms. The s<em>IL</em>-15R alpha displayed high affinity for <em>IL</em>-15 and behaved as a potent and specific inhibitor of <em>IL</em>-15 binding to the membrane receptor, and of <em>IL</em>-15-induced cell proliferation (IC(50) in the range from 3 to <em>20</em> pM). These results suggest that <em>IL</em>-15R alpha shedding may play important immunoregulatory functions.

Human mesenchymal stem cells (hMSCs) are bone marrow-derived stromal cells, which play a role in tumor progression. We have shown earlier that breast cancer cells secrete higher levels of interleukin-6 (<em>IL</em>-6) under hypoxia, leading to the recruitment of hMSCs towards hypoxic tumor cells. We found that (i) MDA-MB-231 cells secrete significantly higher levels of lactate (3-fold more) under hypoxia (1% O(2)) than under <em>20</em>% O(2) and (ii) lactate recruits hMSCs towards tumor cells by activating signaling pathways to enhance migration. The mRNA and protein expression of functional MCT1 in hMSCs is increased in response to lactate exposure. Thus, we hypothesized that hMSCs and stromal carcinoma associated fibroblasts (CAFs) in the tumor microenvironment have the capacity to take up lactate expelled from tumor cells and use it as a source of energy. Our (13)C NMR spectroscopic measurements indicate that (13)C-lactate is converted to (13)C-alpha ketoglutarate in hMSCs and CAFs supporting this hypothesis. To our knowledge this is the first in vitro model system demonstrating that hMSCs and CAFs can utilize lactate produced by tumor cells.

BACKGROUND

In eosinophilic esophagitis (EE), the esophagus is infiltrated with activated eosinophils that often evoke tissue damage, but the intestines of these patients remain unaffected. We thus hypothesized that different tissue-dwelling eosinophil populations may coexist: activated eosinophils that infiltrate the esophagus and resting eosinophils that reside in unaffected intestines. We sought to characterize different eosinophil subpopulations by comparing the expression of certain proinflammatory proteins in tissue-dwelling eosinophils at different parts of the gastrointestinal tract.

METHODS

The 8 patients participating included 6 men and 2 women with a previously confirmed diagnosis of EE, whose average age was 39.4 years (range, <em>20</em>-55 yr) and average disease duration was 13.6 years (range, 2-26 yr). Controls were 3 men and 1 woman, with a mean age of 43.3 years (range, 29-56 yr) with untreated functional dyspepsia who underwent diagnostic esophagogastroduodenoscopy. Six additional individuals having normal blood eosinophils were recruited for cytokine measurements in blood eosinophils. Immunofluorescence and immunoassays charted expression of CD25 and the TH2 cytokines, interleukin (<em>IL</em>)-4, <em>IL</em>-5, <em>IL</em>-10, and <em>IL</em>-13, in esophageal, intestinal, and blood eosinophils from controls and patients.

RESULTS

Controls showed a small but significant proportion of intestinal, but no blood, eosinophils expressing CD25 and IL-13, suggesting physiologic activation occurring in the digestive tract. On the other hand, eosinophils infiltrating the inflamed esophageal mucosa of patients with EE showed strong evidence of activation, with most expressing CD25, IL-4, and IL-13. Moreover, IL-13-positive intestinal eosinophils were increased in patients compared with controls.

CONCLUSIONS

We thus conclude that tissue-dwelling eosinophils show different and distinct cytokine expression patterns under noninflammatory and inflammatory conditions.

BACKGROUND

The mechanisms leading to muscle wasting in patients with COPD are still uncertain. This study was undertaken to evaluate the relationships among circulating levels of catabolic factors (ie, interleukin [IL]-6 and cortisol), anabolic factors (ie, bioavailable testosterone [Tbio], dehydroepiandrosterone sulfate [DHEAS], and insulin-like growth factor [IGF]-I), and mid-thigh muscle cross-sectional area (MTCSA) in patients with COPD.

METHODS

Serum levels of the above factors were measured in 45 men with COPD (mean [+/- SEM] FEV(1), 43 +/- 3% predicted; mean age, 67 +/- 1 years) and 16 sedentary healthy men of similar age. MTCSA was quantified using CT scanning. Patients with COPD were subdivided into two groups according to the MTCSA (< 70 or>>or= 70 cm(2)).

RESULTS

There was a greater prevalence of hypogonadism (ie, Tbio, < 2 nmol/L) in patients with COPD compared to control subjects (22% vs 0%, respectively). Patients with an MTCSA of < 70 cm(2) had significantly reduced levels of DHEAS compared to those in healthy subjects (p < 0.01). IL-6 levels were significantly higher in both subgroups of COPD patients compared to those in control subjects (p < 0.005). The cortisol/DHEAS, IL-6/DHEAS, IL-6/Tbio, and IL-6/IGF-I ratios were significantly greater in COPD patients with an MTCSA of < 70 cm(2) compared to those in control subjects (p < 0.05). The cortisol/DHEAS and IL-6/DHEAS ratios were also significantly greater in COPD patients with an MTCSA of < 70 cm(2) than in COPD patients with an MTCSA of>>or= 70 cm(2) (p < 0.05). In a stepwise multiple regression analysis, the IL-6/DHEAS ratio explained 20% of the variance in MTCSA (p < 0.005).

CONCLUSIONS

Catabolic/anabolic disturbances were found in COPD patients leading to a shift toward catabolism and possibly to the development of peripheral muscle wasting.

OBJECTIVE

Chronic Prostatitis, or Chronic Pelvic Pain Syndrome [CPPS], is a common disorder characterized by pelvic pain and varying degrees of inflammation in expressed prostatic secretions (EPS). In search of markers to more clearly define CPPS, we compared proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) levels in EPS from men with CPPS, to healthy men and men with Benign Prostatic Hyperplasia (BPH).

METHODS

78 men: controls (n = 16), BPH (n = 14), CPPS IIIA >>/=10 white blood cells per high power field (WBC/hpf) in EPS] (n = 18), CPPS IIIB [<10 WBC/hpf in EPS] (n = 20), and asymptomatic inflammatory prostatitis (AIP) (n = 10) were evaluated for EPS WBC, and IL-1beta and TNF-alpha by ELISA.

RESULTS

IL-1beta and TNF-alpha levels in EPS were usually detectable in men with CPPS IIIA (89% and 45%, respectively) or AIP (90%; 100%), but less often in controls (31%; 17%), BPH (57%; 15%), and CPPS IIIB (35%; 15%) respectively. IL-1beta and TNF-alpha levels were higher in CPPS IIIA versus CPPS IIIB, and in AIP versus controls or BPH (p's <0.001). Cut-points for IL-1beta and TNF-alpha discriminated AIP from controls (predictive values = 94% and 83%, respectively) and CPPS IIIA from CPPS IIIB (predictive values 84% and 100%). Overall, there was a correlation between IL-1beta and TNF-alpha (p <0.003), but no correlation between WBC and IL-1beta (p <0.1) or TNF-alpha (p <0.50).

CONCLUSIONS

Cytokines are frequently present and elevated in the EPS from men with CPPS IIIA and AIP and provide a novel means for identification, characterization and potential management of men with CPPS that differs from traditional methods based on WBC.

During inflammation, polymorphonuclear neutrophils (PMN) are exposed to and influenced by various cytokines, including the chemoattractant interleukin-8 (<em>IL</em>-8). We tested the hypothesis that <em>IL</em>-8 affects apoptosis in PMN. We investigated which <em>IL</em>-8 receptor (RI or RII) might be involved, as well as the role of Bcl-2. Human PMN were isolated and cultured up to 30 hours. Apoptosis was detected by UV and light microscopy, as well as by DNA-fragmentation assay, and quantitated by flow cytometry. Interleukin-8 significantly delayed spontaneous apoptosis at 10, <em>20</em>, and 30 hours in a dose-dependent fashion. Polymorphonuclear neutrophil treatment with the highest concentration of <em>IL</em>-8 (100 nM) decreased the percentage of apoptotic cells from 2.1 +/- 1.5 to 0.8 +/- 0.2 after 10 hours, from 31 +/- 14 to 8 +/- 5 after <em>20</em> hours, and from 47 +/- 15 to 18 +/- 8 after 30 hours of incubation (P < 0.05 for all time points, N = 6). Interleukin-8 also inhibited TNF alpha-mediated PMN apoptosis. Incubation with <em>20</em> ng/ml TNF alpha resulted in 23 +/- 6% apoptotic cells at four hours, whereas pretreatment with <em>IL</em>-8 (50 nM) decreased this percentage to 11 +/- 3 (N = 5, P < 0.05). We next studied the role of both types of <em>IL</em>-8 receptors, RI and RII, by comparing the effect of <em>IL</em>-8 and the product of growth-related oncogene alpha (Gro alpha) on PMN cultured for <em>20</em> hours. Both <em>IL</em>-8 and Gro alpha attenuated apoptosis, although <em>IL</em>-8 was more effective than Gro alpha. Bcl-2 was detected by intracellular fluorescent antibody cell sorter analysis, Western blot, and reverse transcription-polymerase chain reaction (RT-PCR). Neither resting PMN nor <em>IL</em>-8-treated neutrophils expressed BCL-2 protein, which was readily detected in control cells. Furthermore, we could not detect BCL-2 gene expression by RT-PCR. We conclude that <em>IL</em>-8 prolongs the lifespan of human neutrophils in vitro by delaying apoptosis. This effect may be important for a controlled and effective inflammatory response. The delay in apoptosis can be mediated by the <em>IL</em>-8 RII, while RI may provide an added effect. The actions of <em>IL</em>-8 on apoptosis are Bcl-2 independent.

Limited data in children with cystic fibrosis (CF) suggest that respiratory viral infections during infancy result in substantial morbidity. Eighty of 101 (79%) infants with CF diagnosed by neonatal screening during 1991-1996 were recruited into a prospective, multiple-birth cohort study. We aimed to perform an initial, then annual bronchoalveolar lavage (BAL) for bacterial and viral culture, cytology, <em>IL</em>-8, and elastolytic activity over the following 2 years. When possible, BAL was also performed during any hospitalization for a pulmonary exacerbation, and additional specimens for viral culture were collected by nasopharyngeal aspiration. Thirteen infants undergoing bronchoscopy for congenital stridor served as disease controls. During infancy, 31 children (39%) were hospitalized for respiratory disease and <em>20</em> (65%) cases had an etiologic agent identified. Respiratory viruses were detected in 16/31 (52%) cases, including four with simultaneous bacterial infection. Another four were infected with Staphylococcus aureus. Respiratory syncytial virus predominated and was found in seven infants. In the absence of bacteria, those with viral infections had acute onset of respiratory distress, were not treated with antibiotics, and had an uncomplicated hospital course. Compared to noninfected CF subjects and controls, infected infants had elevated BAL inflammatory indices (P < 0.01). Eleven of 31 (35%) hospitalized infants followed for 12-60 months acquired Pseudomonas aeruginosa, compared with only three of 49 (6%) subjects not hospitalized for respiratory symptoms during infancy (risk ratio 5.8, CI 1.9, 24). We conclude that respiratory viruses are important causes of hospitalization in CF infants. While viral infections were self-limited, they were accompanied by airway inflammatory changes, and admission to hospital was associated with early acquisition of Pseudomonas aeruginosa and persistent respiratory symptoms.

The aim of our study was to assess the cytokine profile of sickle cell disease (SCD) patients in steady state and in vaso-occlusive crisis (VOC). VOC has a complex nature, involving interactions between sickle red blood cells (RBC), the endothelium, and leucocytes. Endothelial damage due to recurrent adhesion of sickle RBCs may disrupt endothelial function, leading to altered cytokine release. It is therefore pertinent to study the cytokine profile of SCD patients in steady state and in crisis prior to exploring its contribution to vaso-occlusive manifestations, since it is believed that an altered balance of proinflammatory and anti-inflammatory cytokines plays an important role in painful crisis. Cytokines including <em>IL</em>-1beta, <em>IL</em>-2, <em>IL</em>-4, <em>IL</em>-6, <em>IL</em>-8, TNF-alpha, and IFN-gamma were measured by commercially available ELISA kits in SCD patients (n = 60); in steady state (n = 26) and in painful crisis (n = 34) and compared with nonanemic age- and sex-matched normal Omani controls (n = <em>20</em>). SCD patients in crisis showed elevated levels of TNF-alpha (P < 0.092) and <em>IL</em>-6 (P < 0.024) when compared with steady state. It was also observed that SCD patients in steady state showed a significant elevation in <em>IL</em>-1beta (P < 0.04), <em>IL</em>-6 (P < 0.0001), and IFN-gamma (P < 0.02) as compared to normal subjects. It is thus evident that both type I and type II cytokines are significantly altered in SCD patients. In steady state, type II proinflammatory cytokines are elevated, whereas in crisis, an additional augmentation of type I cytokines occurs, with persistent elevation of type II cytokines, emphasizing the role of perturbed endothelium and activated monocytes in the pathophysiology of vaso-occlusion in sickle cell crisis.

BACKGROUND

Airway inflammation is associated with asthma exacerbation risk, treatment response, and disease mechanisms.

OBJECTIVE

This study aimed to identify and validate a sputum gene expression signature that discriminates asthma inflammatory phenotypes.

METHODS

An asthma phenotype biomarker discovery study generated gene expression profiles from induced sputum of 47 asthmatic patients. A clinical validation study (n = 59 asthmatic patients) confirmed differential expression of key genes. A 6-gene signature was identified and evaluated for reproducibility (n = 30 asthmatic patients and n = <em>20</em> control subjects) and prediction of inhaled corticosteroid (ICS) response (n = 71 asthmatic patients). Receiver operating characteristic curves were calculated, and area under the curve (AUC) values were reported.

RESULTS

From 277 differentially expressed genes between asthma inflammatory phenotypes, we identified 23 genes that showed highly significant differential expression in both the discovery and validation populations. A signature of 6 genes, including Charcot-Leydon crystal protein (CLC); carboxypeptidase A3 (CPA3); deoxyribonuclease I-like 3 (DNASE1L3); IL-1β (IL1B); alkaline phosphatase, tissue-nonspecific isozyme (ALPL); and chemokine (C-X-C motif) receptor 2 (CXCR2), was reproducible and could significantly (P < .0001) discriminate eosinophilic asthma from other phenotypes, including patients with noneosinophilic asthma (AUC, 89.6%), paucigranulocytic asthma (AUC, 92.6%), or neutrophilic asthma (AUC, 91.4%) and healthy control subjects (AUC, 97.6%), as well as discriminating patients with neutrophilic asthma from those with paucigranulocytic asthma (AUC, 85.7%) and healthy control subjects (AUC, 90.8). The 6-gene signature predicted ICS response (>12% change in FEV1; AUC, 91.5%). ICS treatment reduced the expression of CLC, CPA3, and DNASE1L3 in patients with eosinophilic asthma.

CONCLUSIONS

A sputum gene expression signature of 6 biomarkers reproducibly and significantly discriminates inflammatory phenotypes of asthma and predicts ICS treatment response. This signature has the potential to become a useful diagnostic tool to assist in the clinical diagnosis and management of asthma.

OBJECTIVE

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

BACKGROUND

In older adults, studies demonstrate an inverse relationship between physical function and individual inflammatory biomarkers. Given that the inflammatory response is a complex system, a combination of biomarkers may increase the strength and consistency of these associations. This study uses principal component analysis to identify inflammatory "component(s)" and evaluates associations between the identified component(s) and measures of physical function.

METHODS

Principal component analysis with a varimax rotation was used to identify two components from eight inflammatory biomarkers measured in 1,269 older persons. The study sample is a subset of the Health, Aging, and Body Composition study.

RESULTS

The two components explained 56% of the total variance in the data (34%, component 1 and 22%, component 2). Five markers (tumor necrosis factor-alpha [TNF-alpha], sTNFRI, sTNFRII, interleukin [<em>IL</em>]-6sR, <em>IL</em>-2sR) loaded highest on the first component (TNF-alpha related), whereas three markers (C-reactive protein [CRP], <em>IL</em>-6, plasminogen activator inhibitor-1) loaded highest on the second component (CRP related). After adjusting for age, sex, race, site, sampling indicator, total lean and fat mass, physical activity, smoking, and anti-inflammatory drug use, knee strength and a physical performance battery score were inversely related to the TNF-alpha-related component, but not to the CRP-related component (knee strength: betaTNFalpha = -2.71, p = .002; betaCRP = -0.88, p = .325; physical performance battery score: betaTNFalpha = -0.05, p < .001; betaCRP = -0.02, p = .171). Both components were positively associated with 400-m walk time, inversely associated with grip strength, and not associated with <em>20</em>-m walking speed.

CONCLUSIONS

At least two inflammatory components can be identified in an older population, and these components have inconsistent associations with different aspects of physical performance.

CD4+ Th2 cells are important regulators of allergic inflammation. CCR8 is thought to play a role in Th2-mediated responses, however, expression of CCR8 in peripheral blood has not been fully characterized. Using a fluorescent form of the ligand selective for CCR8 (F-CCL1), we identified the leukocytes expressing CCR8 in human, monkey, and mouse peripheral blood. CCR8 expression is primarily restricted to a subset of human CD4 memory T lymphocytes (15%). Approximately 40% of CCR8+CD4+ T cells express Th2 cytokines <em>IL</em>-4 or <em>IL</em>-13 while 13% express the Th1 cytokine IFN-gamma. In fact, 50% of all Th2, but only 5% of Th1, cells express CCR8. Upon anti-CD3/anti-CD28 mAb-mediated activation, CCR8+CD4+ T cells secrete 3- to 7-fold higher levels of <em>IL</em>-4, <em>IL</em>-5, <em>IL</em>-9, and <em>IL</em>-13 and 10- to <em>20</em>-fold lower levels of IFN-gamma or <em>IL</em>-17, compared with CCR8-CD4+ memory T cells. Two-thirds of CCR8+CD4 T cells express cutaneous lymphocyte-associated Ag while the majority lack gut-homing receptors. CCR8+CD4+ cells express CCR7 and CD62L and are present in spleen and lymph nodes of mice. Approximately 25% of CCR8+CD4 T cells express CD25high while <em>20</em>% of CCR8+CD4+ express the T regulatory cell transcription factor FOXP3 accounting for 60% of all FOXP3-expressing CD4+ T cells. In conclusion, CCR8 marks a diverse subset of CD4 memory T cells enriched for T regulatory and Th2 cells which have the potential for recruitment into sites of allergic inflammation where they could participate in the induction and regulation of the allergic response.

BACKGROUND

Anti-IL-5 might be a useful therapeutic agent for eosinophilic disorders, yet its immunologic consequences have not been well characterized.

OBJECTIVE

We sought to characterize the hematologic and immunologic effects of anti-IL-5 in human subjects.

METHODS

The effects of 3-month infusions of mepolizumab were assessed in 25 patients with a variety of eosinophilic syndromes. Samples with increased IL-5 levels after therapy were analyzed by using size exclusion filtration. Immunoreactive IL-5 fraction and plasma samples were subsequently precipitated with saturating concentrations of protein A/G.

RESULTS

Twenty-three patients responded to anti-IL-5 therapy with a decrease in blood eosinophil counts and a reduced percentage of CCR3(+) cells by 20- and 13-fold, respectively (P < .0001). Responsiveness was not related to the levels of baseline plasma IL-5 or the presence of FIP1L1-PDGFRA fusion gene. Persistently decreased blood eosinophilia remained for 3 months after final infusion in 76% of subjects. Therapy was associated with a large increase in blood IL-5 levels, likely because of a circulating IL-5/mepolizumab complex precipitated with protein A/G, a significant increase in eosinophil IL-5 receptor alpha expression, and increased percentage of CD4(+) and CD8(+) cells producing intracellular IL-5 (P < .05). Additionally, anti-IL-5 therapy decreased eotaxin-stimulated eosinophil shape change ex vivo.

CONCLUSIONS

Anti-IL-5 therapy induces a dramatic and sustained decrease in blood eosinophilia (including CCR3(+) cells), decreased eosinophil activation, and increased circulating levels of IL-5 in a variety of eosinophilic disorders. Increased levels of IL-5 receptor alpha and lymphocyte IL-5 production after anti-IL-5 therapy suggest an endogenous IL-5 autoregulatory pathway.

We report the first safety and immunogenicity trial of the Plasmodium falciparum vaccine candidate FMP2.1/AS02A, a recombinant E. coli-expressed protein based upon the apical membrane antigen-1 (AMA-1) of the 3D7 clone formulated with the AS02A adjuvant. We conducted an open-label, staggered-start, dose-escalating Phase I trial in 23 malaria-naïve volunteers who received 8, <em>20</em> or 40microg of FMP2.1 in a fixed volume of 0.5mL of AS02A on a 0, 1, and 2 month schedule. Nineteen of 23 volunteers received all three scheduled immunizations. The most frequent solicited local and systemic adverse events associated with immunization were injection site pain (68%) and headache (29%). There were no significant laboratory abnormalities or vaccine-related serious adverse events. All volunteers seroconverted after second immunization as determined by ELISA. Immune sera recognized sporozoites and merozoites by immunofluorescence assay (IFA), and exhibited both growth inhibition and processing inhibition activity against homologous (3D7) asexual stage parasites. Post-immunization, peripheral blood mononuculear cells exhibited FMP2.1-specific lymphoproliferation and IFN-gamma and <em>IL</em>-5 ELISPOT assay responses. This is the first PfAMA-1-based vaccine shown to elicit both potent humoral and cellular immunity in humans. Encouraged by the potential of FMP1/AS02A to target host immunity against PfAMA-1 that is known to be expressed by sporozoite, hepatic and erythrocytic stages, we have initiated field trials of FMP2.1/AS02A in an endemic population in the Republic of Mali.

Interleukin-16, a proinflammatory cytokine produced in CD8(+) lymphocytes, is synthesized as a precursor protein (pro-<em>IL</em>-16). It is postulated that the C-terminal region of pro-<em>IL</em>-16 is cleaved, releasing bioactive <em>IL</em>-16. To characterize <em>IL</em>-16 cleavage, we transfected COS cells with a cDNA encoding a approximately 50-kDa form of pro-<em>IL</em>-16. Transfected COS cells released a approximately <em>20</em>-kDa <em>IL</em>-16 cleavage product shown to consist of the 121 C-terminal residues of pro-<em>IL</em>-16 by immunoblotting and amino acid sequencing. Cleaved <em>IL</em>-16, but not pro-<em>IL</em>-16, exhibited lymphocyte chemoattractant activity. A C-terminal approximately <em>20</em>-kDa <em>IL</em>-16 polypeptide was also released when pro-<em>IL</em>-16 was treated with concanavalin A-stimulated CD8(+) lymphocyte lysate. Cleavage occurred after an Asp, suggesting involvement of a caspase (interleukin-1beta-converting enzyme/CED-3) family protease. Using recombinant caspases and granzyme B, we determined that pro-<em>IL</em>-16 cleavage is mediated only by caspase-3. Relevance to pro-<em>IL</em>-16 processing in primary lymphocytes was supported by identifying the p<em>20</em> subunit of activated caspase-3 in stimulated CD8(+) lymphocytes and by inhibition of CD8(+) lymphocyte lysate-mediated cleavage with Ac-DEVD-CHO. Pro-<em>IL</em>-16 is a substrate for caspase-3, and cleavage by this enzyme releases biologically active <em>IL</em>-16 from its inactive precursor.

Despite the reduced incidence of gastric cancer in the developed world, a diagnosis of stomach carcinoma still carries a poor prognosis due to the asymptomatic nature of the disease in the early stages, subsequent advanced stage diagnosis, and a low 5 year survival rate. Endoscopy remains the primary standard for diagnosis of stomach carcinoma and the current marker, carbohydrate antigen 19-9 (CA19-9) lacks the levels of sensitivity and specificity required in order to make it clinically useful for diagnostic monitoring. Therefore, there is a current need for additional markers to improve the diagnostic accuracy for the early stages of stomach cancer. Together, glycomic, proteomic, and glycoproteomic analyses of serum have the potential to identify such probable markers. A discovery study is reported here using preoperative serum from 80 stomach cancer patients, 10 patients bearing benign stomach disease, and <em>20</em> matched controls. Glycomic analysis of the total and immunoaffinity depleted serum revealed statistically significant increases in the levels of sialyl Lewis X epitopes (SLe(X)) present on triantennary glycans accompanied by increased levels of core fucosylated agalactosyl biantennary glycans present on IgG (referred to as the IgG G0 glycoform) which are associated with increasing disease pathogenesis. Protein expression analysis using 2D-DiGE returned a number of differentially expressed protein candidates in the depleted serum, many of which were shown to carry triantennary SLe(X) during subsequent glycomic investigations. Biological pathway analysis of the experimental data returned complement activation and acute phase response signaling as the most significantly altered pathways in the stomach cancer patient serum. Upon the basis of these findings, it is suggested that increased expression of IgG G0 and complement activation are a host response to the presence of the stomach tumor while the increased expression of SLe(X) and acute phase response proteins is a result of pro-inflammatory cytokine signaling, including <em>IL</em>-6, during carcinogenesis. The approach presented herein provides an insight into the underlying mechanisms of disease and the resulting changes in the glycome and glycoproteome offer promise as potential markers for diagnosis and prognostic monitoring in stomach cancer.

It has been proposed that mitogen-activated protein kinase (MAPK) pathways may play a role in the regulation of pro-inflammatory cytokines, such as interlukine-1, during cerebral ischemia. Our previous study showed that extracellular-signal-regulated kinases 1 and 2 (ERK 1/2) were activated during focal cerebral ischemia in mice [J. Cereb. Blood Flow Metab. <em>20</em> (<em>20</em>00) 13<em>20</em>]. However, the effect of ERK 1/2 activation in focal cerebral ischemia is still unclear. In this study we reported that in vivo phospho-ERK 1/2 expression increased following 30 min of middle cerebral artery occlusion (MCAO) in the mouse brain in both the ischemic core and perifocal regions. Western blot analysis and immunohistochemistry demonstrated that pro-treatment with 1,4-diamino-2,3-dicyano-1,4-bis butadiene (U0126) [J. Biol. Chem. 273 (1998) 18623] could significantly inhibit mouse brain phospho-MEK 1/2 and phospho-ERK 1/2 expression after 1-2 h of MCAO (p<0.05). Compared to the control group of mice, brain infarct volume was significantly decreased after 24 h of MCAO in the U0126-treated mice (27+/-6 vs. 46+/-9 mm(2), p<0.05). Inhibition of the MEK/ERK 1/2 pathway also prevented downstream kinase Elk-1 phosphorylation, and further reduced cytokine <em>IL</em>-1beta mRNA, but not TNFalpha, <em>IL</em>-1alpha, or chemokine MIP-1alpha mRNA expression. Our data demonstrates that in vivo the close linking of MEK 1/2, ERK 1/2, Elk-1, and <em>IL</em>-1 mRNA expression in the cerebral ischemia animals suggests that ERK 1/2 pathway activation is important in pro-inflammatory cytokine <em>IL</em>-1beta signaling, which induces an inflammatory response and exacerbates ischemic brain injury. Inhibiting the ERK 1/2 pathway may therefore provide a novel approach for the reduction of ischemia-induced <em>IL</em>-1beta overexpression.

OBJECTIVE

to characterize the transcriptome of human myometrium during spontaneous labor at term.

METHODS

myometrium was obtained from women with (n=19) and without labor (n=<em>20</em>). Illumina HumanHT-12 microarrays were utilized. Moderated t-tests and false discovery rate adjustment of P-values were applied. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed for a select set of differentially expressed genes in a separate set of samples. Enzyme-linked immunosorbent assay and Western blot were utilized to confirm differential protein production in a third sample set.

RESULTS

1) Four hundred and seventy-one genes were differentially expressed; 2) gene ontology analysis indicated enrichment of 103 biological processes and 18 molecular functions including: a) inflammatory response; b) cytokine activity; and c) chemokine activity; 3) systems biology pathway analysis using signaling pathway impact analysis indicated six significant pathways: a) cytokine-cytokine receptor interaction; b) Jak-STAT signaling; and c) complement and coagulation cascades; d) NOD-like receptor signaling pathway; e) systemic lupus erythematosus; and f) chemokine signaling pathway; 4) qRT-PCR confirmed over-expression of prostaglandin-endoperoxide synthase-2, heparin binding epidermal growth factor (EGF)-like growth factor, chemokine C-C motif ligand 2 (CCL2/MCP1), leukocyte immunoglobulin-like receptor, subfamily A member 5, interleukin (IL)-8, IL-6, chemokine C-X-C motif ligand 6 (CXCL6/GCP2), nuclear factor of kappa light chain gene enhancer in B-cells inhibitor zeta, suppressor of cytokine signaling 3 (SOCS3) and decreased expression of FK506 binding-protein 5 and aldehyde dehydrogenase in labor; 5) IL-6, CXCL6, CCL2 and SOCS3 protein expression was significantly higher in the term labor group compared to the term not in labor group.

CONCLUSIONS

myometrium of women in spontaneous labor at term is characterized by a stereotypic gene expression pattern consistent with over-expression of the inflammatory response and leukocyte chemotaxis. Differential gene expression identified with microarray was confirmed with qRT-PCR using an independent set of samples. This study represents an unbiased description of the biological processes involved in spontaneous labor at term based on transcriptomics.