[Observation of ultrastructure and ECP expression in nasal polyps]

OBJECTIVE

To observe the ultrastructural feature and ECP expression in nasal polyps, and aim to explore its role in the pathogenesis of CRSwNP.

METHOD

5 CRSwNP, 5 CRS and 5 control patients underwent sinus surgery were gathered to detect its ultrastructure and expression of ECP by in situ hybridization and electron microscopy technique.

RESULT

Under electron microscopy, the eosinophilic cells in CRSwNP group increased, its membrane was intact but fold, the feature of pseudopodium, degranulation and cavitation were all found. The expression level of ECP mRNA was up-regulated.

CONCLUSION

The findings suggest that eosinophilic infiltrate and ECP cytologic inflammation reactions may involve in the pathogenesis of CRSwNP.

Persistent airway inflammation and bronchial hyperresponsiveness in patients with totally controlled asthma

OBJECTIVE

A proportion of asthmatic patients can achieve total control according to the Global Initiative for Asthma/National Institute of Health guidelines. The aim of this study was to investigate whether total control of asthma is accompanied by the remission of airway inflammation and bronchial hyperresponsiveness.

METHODS

We assessed the number of eosinophil and the levels of eosinophil cationic protein (ECP) and interleukin (IL)-5 in induced sputum and bronchial responsiveness to methacholine in 76 patients with totally controlled asthma in comparison with 30 current untreated asthmatics and 20 healthy subjects.

RESULTS

We found significantly higher number of eosinophil and higher levels of ECP and IL-5 in the total control group than those in healthy subjects (6.9% +/- 3.6% and 1.3% +/- 1.1%, 129.0 +/- 53.8 mug/l and 48.9 +/- 20.4 mug/l, 22.1 +/- 15.2 mug/l and 10.6 +/- 5.2 mug/l, respectively; p < 0.001), but lower than those in current asthma group (16.2% +/- 8.6%, 362.2 +/- 151.6 mug/l, 50.6 +/-25.8 mug/l, respectively; p < 0.001). Sixty-five (85.5%) patients with totally controlled asthma showed positive methacholine challenge test. In the total control group, number of eosinophil and the levels of ECP and IL-5 in induced sputum of patients with negative methacholine challenge test were significantly lower than those in subjects with positive methacholine challenge test (p < 0.001), whereas sputum number of eosinophil and the levels of ECP and IL-5 in patients with negative methacholine challenge test and those of healthy subjects were similar (p > 0.05).

CONCLUSION

The results of this study suggest that airway inflammation and bronchial hyperresponsiveness still persisted during total control of asthma.

The cytotoxicity of eosinophil cationic protein/ribonuclease 3 on eukaryotic cell lines takes place through its aggregation on the cell membrane

Human eosinophil cationic protein (ECP)/ ribonuclease 3 (RNase 3) is a protein secreted from the secondary granules of activated eosinophils. Specific properties of ECP contribute to its cytotoxic activities associated with defense mechanisms. In this work the ECP cytotoxic activity on eukaryotic cell lines is analyzed. The ECP effects begin with its binding and aggregation to the cell surface, altering the cell membrane permeability and modifying the cell ionic equilibrium. No internalization of the protein is observed. These signals induce cell-specific morphological and biochemical changes such as chromatin condensation, reversion of membrane asymmetry, reactive oxygen species production and activation of caspase-3-like activity and, eventually, cell death. However, the ribonuclease activity component of ECP is not involved in this process as no RNA degradation is observed. In summary, the cytotoxic effect of ECP is attained through a mechanism different from that of other cytotoxic RNases and may be related with the ECP accumulation associated with the inflammatory processes, in which eosinophils are present.

Eosinophil cationic protein stimulates TGF-beta1 release by human lung fibroblasts in vitro

Eosinophilic inflammation and airway remodeling are features of asthma. Eosinophil cationic protein (ECP) is released by activated eosinophils and transforming growth factor (TGF)-beta(1) has major functions in the fibrotic process. We therefore hypothesized that ECP stimulates TGF-beta(1) release by human lung fibroblasts. Fibroblasts in monolayer displayed a constitutive release of TGF-beta(1), which increased in presence of ECP (436 +/- 60 vs. 365 +/- 48 pg/ml at 48 h; P < 0.01). mRNA expression of TGF-beta(1) was almost twofold in ECP-stimulated fibroblasts. ECP in three-dimensional cultures stimulated both TGF-beta(1) release (180 +/- 61 vs. 137 +/- 54 pg/ml; P < 0.01) and fibroblast-mediated collagen gel contraction (28 vs. 39% of initial gel area at 48 h; P < 0.001). ECP stimulates TGF-beta(1)-release by human lung fibroblasts, suggesting a potential mechanism for eosinophils in the fibrotic response. This may be an important mechanism by which ECP promotes remodeling of extra cellular matrix leading to airway fibrosis in asthmatics.

Clinical and biological efficacy of preservative-free NAAGA eye-drops versus levocabastine eye-drops in vernal keratoconjunctivitis patients

AIMS

This comparative and randomised pilot study assessed the clinical and biological efficacy of Naaxia Sine(R) eye-drops versus levocabastine eye-drops in the treatment of vernal keratoconjunctivitis (VKC).

METHODS

Twenty-three VKC patients were randomised and treated bilaterally for 28 days with N-acetyl-aspartyl-glutamate (NAAGA) or levocabastine (LEVO) eye-drops. The primary efficacy variable, overall evolution of eosinophil cationic protein (ECP) tear concentrations, was assessed in a masked fashion on D0, D7 and D28. Clinical symptoms and signs were reported at the same time points. Biological parameters were analysed with a non-parametric rank-based approach. Global tolerance was assessed by the investigator and patient.

RESULTS

At all time points, ECP tear levels were significantly reduced in the NAAGA compared with the LEVO group (p = 0.023). Reduction of eosinophil leucocytes and tear lymphocytes was higher not significant in the NAAGA group. The same trend was observed for the evolution of total ocular symptom score. There were no significant differences between treatment groups in the occurrence of adverse effects, except for burning which was more frequent in the LEVO group (p = 0.002).

CONCLUSION

The anti-eosinophilic actions of NAAGA were shown by a significant reduction of ECP tear concentrations. A decreased lymphocyte count and an overall improvement of the symptomatology were also noted. Moreover, the tolerability of NAAGA appeared to be better.

Histamine H4 receptor expression is elevated in human nasal polyp tissue

Altered histamine metabolism is thought to be involved in the pathomechanism of nasal polyposis characterized by local eosinophil infiltration. The present study was performed to determine whether histamine receptors play a role in the effect of histamine in nasal polyp tissue. The findings suggest that the expression of H1 and H4 receptors is elevated in polyp tissue (p=0.045; p<0.001), while the level of H2 and H3 receptors is not increased significantly. The elevation of H1 and H4 receptors' expression may indicate that the histamine related mechanisms are preferentially mediated through H1 and H4 histamine receptors in the polyp tissue. Simultaneously with increased H4 receptor expression, the concentration of eosinophil cationic protein (ECP) was increased significantly in polyp tissue (p=0.002). One may speculate that the H4 receptor mediated histamine effects have a role in eosinophil accumulation and activation in inflammatory diseases of the nasal and paranasal sinus mucosa, such as nasal polyposis.

The functional heterogeneity of eosinophil cationic protein is determined by a gene polymorphism and post-translational modifications

BACKGROUND

The eosinophil is a cytotoxic cell and takes part in parasite killing and tissue-destructive processes by secretion of proteins such as eosinophil cationic protein (ECP). A polymorphism was demonstrated in the ECP gene, giving rise to a substitution of arginine at position 97 with threonine. This polymorphism is related to disease development.

OBJECTIVE

To investigate the functional and molecular heterogeneity of native ECP and the functional consequences of the replacement of arginine with a threonine.

METHODS

ECP was purified from healthy blood donors by gel filtration, ion-exchange chromatography and reversed-phase chromatography. Recombinant ECPs i.e. rECP 97(arg) and rECP 97(thr) were produced by the pFASTBAC baculovirus expression system. The cytotoxic activity was determined against an erythroleukaemia or a small cell lung cancer cell line.

RESULTS

Native ECP was purified to apparent homogeneity and showed a considerable molecular heterogeneity and a corresponding functional heterogeneity with respect to cytotoxic activity. After reduction, the native cytotoxic ECP showed three bands on sodium dodecylsulphate polyacrylamide gel electrophoresis : one major band at 18-20 kDa and two minor bands at about 10 and 5 kDa, respectively. The 5 kDa contained two masses differing with 56.2 Da, which corresponds to the difference in molecular masses of arginine and threonine. rECP 97(arg) was cytotoxic in contrast to rECP97(thr). Deglycosylation with N-glycosidase F did not affect the cytotoxic activity of native ECP to any measurable extent nor the activity of rECP 97(arg), whereas rECP 97(thr) achieved cytotoxic activity. The RNase activities of the recombinant and native ECPs were similar.

CONCLUSION

We conclude that ECP is present in several molecular forms with varying biological activities. Some of this functional heterogeneity is based on the genetic polymorphism of the ECP gene and some on post-translational modifications. In subjects carrying the ECP 97(thr) variant, the cytotoxic activity may be disguised by N-linked glycosylation of the active site.

Surfactant protein D regulates chemotaxis and degranulation of human eosinophils

The collectin surfactant protein D (SP-D) is an important component of the pulmonary innate host defence. Up to now, little is known about the regulation of eosinophil function by SP-D. Various murine models of pulmonary hypersensitivity suggest that SP-D may be a potent anti-allergic protein. We investigated the modulation of eosinophil chemotaxis and degranulation by human SP-D. SP-D markedly inhibited the chemotaxis of eosinophils triggered by eotaxin, a major tissue-derived CC-chemokine, as shown in a modified Boyden chamber assay. In addition, degranulation of ECP in response to Ca2+ ionophore, immobilized IgG and serum from allergic patients was inhibited by SP-D. In a fixed-cell enzyme linked immunosorbent assay and in flow cytometry, SP-D bound to eosinophils. This binding was saturable and was inhibited by the addition of maltose and ethylenediaminetetraacetic acid, suggesting the involvement of the carbohydrate recognition domain of SP-D. In addition, flow cytometry showed significant interaction of SP-D with CD32 (FcgammaII receptor) on eosinophils, which might explain the inhibitory effect of SP-D on the IgG and serum-triggered eosinophil cationic protein degranulation of eosinophils. Our data further support the concept of an anti-inflammatory function of SP-D in the lung of patients with allergic diseases.

Signal peptide of eosinophil cationic protein upregulates transforming growth factor-alpha expression in human cells

Eosinophil cationic protein (ECP) is a major component of eosinophil granule protein that is used as a clinical bio-marker for asthma and allergic inflammatory diseases. Previously, it has been reported that the signal peptide of human ECP (ECPsp) inhibits the cell growth of Escherichia coli (E. coli) and Pichia pastoris (P. pastoris), but not mammalian A431 cells. The inhibitory effect is due to the lack of human signal peptide peptidase (hSPP), a protease located on the endoplasmic reticulum (ER) membrane, in the lower organisms. In this study, we show that the epidermal growth factor receptor (EGFR) is upregulated by the exogenous ECPsp-eGFP as a result of the increased expression of the transforming growth factor-alpha (TGF-alpha) at both transcriptional and translational levels in A431 and HL-60 clone 15 cell lines. Furthermore, the N-terminus of ECPsp fragment generated by the cleavage of hSPP (ECPspM1-G17) gives rise to over threefold increase of TGF-alpha protein expression, whereas another ECPsp fragment (ECPspL18-A27) and the hSPP-resistant ECPsp (ECPspG17L) do not show similar effect. Our results indicate that the ECPspM1-G17 plays a crucial role in the upregulation of TGF-alpha, suggesting that the ECPsp not only directs the secretion of mature ECP, but also involves in the autocrine system.

Lower airway inflammation before and after house dust mite nasal challenge: an age and allergen exposure-related phenomenon

BACKGROUND

Upper and lower airways allergic disease is currently considered unitarily. Allergic inflammation in one site can extend to other sites of the respiratory tract.

OBJECTIVE

To evaluate bronchial inflammation before and after allergen-specific nasal challenge (ASNC) in rhinitic and asthmatic children, considering the different levels of allergen exposure, i.e. summer (low) and winter (high).

METHODS

Fourteen children with rhinitis and 15 with rhinitis and asthma, all monosensitized to mites and 10 healthy controls were studied. Nasal IgE were measured before ASNC in summer and in winter season. Nasal clinical score, eosinophil cationic protein (ECP), nasal tryptase, bronchial clinical score, FEV(1), PEF, sputum ECP, sputum tryptase and exhaled nitric oxide (eNO) were evaluated before and after ASNC in summer and winter season.

RESULTS

Nasal scores significantly increased after ASNC in rhinitic and asthmatic children in both seasons. Nasal IgE were significantly higher in summer compared to winter. Bronchial symptoms, FEV(1) and PEF showed no mean differences in rhinitic and asthmatic children after ASNC, with an increase of bronchial symptoms and a decrease of FEV(1) and PEF occurring in 3/15 asthmatic children. In both groups nasal tryptase and ECP after ASNC significantly increased in summer and winter, while sputum tryptase was undetectable before or after ASNC in both groups. Sputum ECP and eNO at baseline were significantly higher in patients than in controls (summer P=0.002, winter P=0.001). Sputum ECP significantly increased after ASNC in 3/15 asthmatics in summer and in 11/15 in winter, as well as in 3/14 rhinitics in summer and in 4/14 in winter. eNO significantly increased after ASNC in 3/15 asthmatics in summer and in 10/15 in winter, and in 1/14 rhinitics in summer and in 4/14 in winter. A significant median increase of sputum ECP (P=0.0007) and eNO (P=0.0012) after ASNC in asthmatic and of eNO (P=0.013) in rhinitic children was also found in winter.

CONCLUSIONS

Basal sputum ECP and eNO values, significantly higher before ASNC in rhinitic patients compared to control subjects, confirm the inflammatory link of upper and lower airways. The more frequent detection of inflammatory changes induced by ASNC in winter suggests that allergen exposure favours the transfer of nasal inflammation to lower airways.

Montelukast decreases plasma endothelin-1 and serum eosinophil cationic protein levels in paediatric atopic asthma

BACKGROUND AND OBJECTIVE

Endothelin-1 (ET-1) is produced by vascular endothelial cells and epithelial cells, T-lymphocytes and phagocytes. Increased ET-1 levels have been demonstrated in the bronchial epithelium of asthma patients. In vitro, ET-1 stimulates mucus secretion, activates proinflammatory cells - macrophages and mast cells - and serves as a mitogenic stimulus for fibroblasts and smooth muscle. In addition, ET-1 activates phospholipase 2. Compared with healthy individuals, asthma patients have increased ET-1 levels during an attack and following stabilisation. Our study was designed to examine plasma ET-1 (P-ET) levels in paediatric atopic patients newly diagnosed with persistent mild bronchial asthma and 1 month after initiation of montelukast therapy.

METHODS

Patients' histories were examined, and their blood eosinophil leucocyte count and levels of total serum immunoglobulin E (S-IgE), serum eosinophil cationic protein (S-ECP) and P-ET were determined. Thirty-six patients with persistent mild bronchial asthma were treated with the leukotriene receptor antagonist montelukast, administered once a day for 4 weeks. Second P-ET and S-ECP level determinations were made 4 weeks later with all the children included in the study. P-ET levels were also determined in a group of 27 healthy children who had no atopy in their medical histories and were taking no drugs (including montelukast), and who served as controls.

RESULTS

The mean +/- SD pretreatment P-ET level in the 36 study children was 11.542 +/- 6.408 pg/L, and this decreased to 5.636 +/- 4.419 pg/L after 1 month's therapy with montelukast (statistically significant difference; p < 0.0001). Both of these values were significantly higher (p < 0.0001 and p < 0.031, respectively) than the mean level in the control group of 27 children (3.543 +/- 2.497 pg/L). The mean pretreatment S-ECP level was 35.78 +/- 19.58 microg/L, and this decreased to 19.54 +/- 13.86 microg/L after 1 month's therapy (p < 0.001).

CONCLUSIONS

This study demonstrated a decrease in P-ET levels in children with mild asthma receiving montelukast. This indicates a reduction in the severity of the inflammatory response and, hence, provides evidence for the anti-inflammatory effect of montelukast. Monitoring both ET-1 and ECP levels at regular follow-up may be useful in assessing these two facets of activity of chronic inflammation in bronchial asthma.

Identification and characterization of an intervening sequence within the 23S ribosomal RNA genes of Edwardsiella ictaluri

Comparison of the 23S rRNA gene sequences of Edwardsiella tarda and Edw. ictaluri confirmed a close phylogenetic relationship between these two fish pathogen species and a distant relation with the 'core' members of the Enterobacteriaceae family. Analysis of the rrl gene for 23S rRNA in Edw. ictaluri revealed the presence of an intervening sequence (IVS) in helix-45. This new 98bp IVS shared 97% nucleotide identity with Salmonella typhimurium helix-45 IVS. Edw. ictaluri helix-45 IVS was present in all Edw. ictaluri strains analyzed and in at least six rrl operons within each cell. Fragmentation of 23S rRNA due to IVS excision by RNase III was observed by methylene blue staining of ribosomal RNA extracted from Edw. ictaluri isolates. This is the first report of an IVS in the 23S rRNA gene of the genus Edwardsiella.

Gastrointestinal food hypersensitivity: symptoms, diagnosis and provocation tests

As many as 25% of the general population in Western countries believe that they suffer from adverse reactions to food. However, the actual prevalence of food allergy is much lower. Food-induced allergic reactions cause a variety of symptoms including cutaneous, gastrointestinal and respiratory tract. Food allergy might be caused by IgE-mediated, mixed (IgE and/or non-IgE) or non-IgE-mediated (cellular) mechanisms. The clinical diagnosis is based on a careful history, laboratory findings (total and specific IgE), skin prick test, elimination diet and food challenges. New intestinal provocation tests have also been applied to pick up the allergic response of the duodenal mucosa by endosonography and external ultrasound. The management of food allergy continues to be a strict avoidance of the offending food item.

Intracellular signaling mechanisms regulating toll-like receptor-mediated activation of eosinophils

Activation of eosinophils by microbe-derived molecules via Toll-like receptors (TLR) potentially provides the link between microbe-induced innate immune responses and the exacerbation of allergic inflammation. We investigated the expression of TLRs and the effect of their ligands on human eosinophils. Expression of TLR1-9 was detected by Western blot and flow cytometry. Adhesion molecules, cytokines, superoxides, and eosinophlilic cationic protein (ECP) were assessed by flow cytometry, enzyme-linked immunosorbent assay, chemiluminescent method, and fluorescence immunoassay, respectively. Human eosinophils differentially expressed TLR1, -2, -4, -5, -6, -7, and -9. Peptidoglycan (PGN) (TLR2 ligand), flagellin (TLR5 ligand), and Imiquimod R837 (TLR7 ligand) could significantly upregulate cell surface expression of intercellular adhesion molecule (ICAM)-1 and CD18, and induce the release of IL-1beta, IL-6, IL-8, growth-related oncogene (GRO)-alpha, and superoxides of eosinophils. Only PGN could induce the degranulation for ECP release. However, ds poly I-C (TLR3 ligand), LPS (TLR4 ligand), ssRNA (TLR8 ligand), and CpG-DNA (TLR9 ligand) were much less effective or inactive. PGN, flagellin, and R837 could activate both nuclear factor (NF)-kappaB and extracellular signal-regulated protein kinase (ERK). PGN could activate phosphatidylinositol 3-kinase (PI3K)-Akt, and R837 both PI3K-Akt and p38 mitogen-activated protein kinase (MAPK). The induction of the release of IL-1beta, IL-6, IL-8, GRO-alpha, superoxides, and ECP by PGN, flagellin, and R837 was found to be differentially regulated by NF-kappaB, ERK, PI3K-Akt, and p38 MAPK. The above results therefore support that microbial infection may lead to the exacerbation of allergic inflammation.

Topography Studies on the Membrane Interaction Mechanism of the Eosinophil Cationic Protein†

The eosinophil cationic protein (ECP) is an antipathogen protein involved in the host defense system. ECP displays bactericidal and membrane lytic capacities [Carreras et al. (2003) Biochemistry 42, 6636-6644]. We have now characterized in detail the protein-membrane interaction process. All observed fluorescent parameters of the wild type and single-tryptophan-containing mutants, as well as the results of decomposition analysis of protein fluorescence, suggest that W10 and W35 belong to two distinct spectral classes I and III, respectively. Tryptophan residues were classified and assigned to distinct structural classes using statistical approaches based on the analysis of tryptophan microenvironment structural properties. W10 belongs to class I and is buried in a relative nonpolar, nonflexible protein environment, while W35 (class III) is fully exposed to free water molecules. Tryptophan solvent exposure and the depth of the protein insertion in the lipid bilayer were monitored by the degree of protein fluorescence quenching by KI and brominated phospholipids, respectively. Results indicate that W35 partially inserts into the lipid bilayer, whereas W10 does not. Further analysis by electron microscopy and dynamic light scattering indicates that ECP can destabilize and trigger lipid vesicle aggregation at a nanomolar concentration range, corresponding to about 1:1000 protein/lipid ratio. No significant leakage of the vesicle aqueous content takes place below that protein concentration threshold. The data are consistent with a membrane destabilization "carpet-like" mechanism.

Steroids reduce local inflammatory mediator secretion and mucosal permeability in collagenous colitis patients

AIM: To study the effect of oral steroids upon clinical response and rectal mucosa secretion of eosinophil cationic protein (ECP), myeloperoxidase (MPO), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and albumin in patients with collagenous colitis (CC).

METHODS: A segmental perfusion technique was used to collect perfusates from rectum of CC patients once before and twice (one and four weeks) after the start of steroid treatment. Clinical data was monitored and ECP, MPO, bFGF, VEGF and albumin concentrations were analyzed by immunochemical methods in perfusates and in serum.

RESULTS: Steroids reduced the number of bowel movements by more than five times within one week and all patients reported improved subjective well-being at wk 1 and 4. At the same time, the median concentrations of ECP, bFGF, VEGF and albumin in rectal perfusates decreased significantly. MPO values were above the detection limit in only 3 patients before treatment and in none during treatment. VEGF, bFGF, ECP and albumin concentrations correlated with each other with the exception of ECP and albumin. A decrease of serum ECP and VEGF concentrations was also seen even if the overtime reduction was not significant.

CONCLUSION: Oral steroid treatment in CC patients induced a simultaneous reduction of bowel movements and rectal release of ECP, bFGF, VEGF and albumin, suggesting that these polypeptides and increased mucosal permeability are important components of the pathophysiology in collagenous colitis.

Eustachian tube function in patients with eosinophilic otitis media associated with bronchial asthma evaluated by sonotubometry

OBJECTIVE

To determine eustachian tube function in patients with asthma and with or without eosinophilic otitis media (EOM), a new middle ear disease entity with a highly viscous middle ear effusion containing many eosinophils and usually associated with bronchial asthma. One of the most important causes of otitis media (OM) is eustachian tube dysfunction.

DESIGN

Retrospective case review.

SETTING

A referral center.

PATIENTS

Twenty patients with EOM and patients with asthma but without OM.

MAIN OUTCOME MEASURES

We studied eustachian tube function using sonotubometry and a questionnaire. Sonotubometry was also performed on 13 control patients with chronic otitis media (COM) and 7 normal controls.

RESULTS

The tubal opening duration was significantly longer in patients with EOM than in patients with asthma but without OM, controls with COM, and normal controls, indicating the presence of patulous eustachian tubes in patients with EOM. Responses to the questionnaire also supported the presence of patulous eustachian tubes in the patients with EOM.

CONCLUSIONS

The presence of a patulous eustachian tube may be a major cause of EOM in patients with bronchial asthma. In patients with asthma who have a helper T-cell 2-dominant predisposition, a patulous eustachian tube easily allows the entry of antigenic materials into the middle ear, causing eosinophil-dominant inflammation.

Eosinophil-derived cationic proteins activate the synthesis of remodeling factors by airway epithelial cells

Eosinophil cationic proteins influence several biological functions of the respiratory epithelium, yet their direct contribution to airway remodeling has not been established. We show that incubation of the human bronchial epithelial cell line, BEAS-2B, or primary cultured human bronchial epithelial cells, normal human bronchial epithelial cells, with subcytotoxic concentrations (0.1, 0.3, and 1 microM) of major basic protein (MBP), or eosinophil peroxidase (EPO), augmented the transcripts of endothelin-1, TGF-alpha, TGF-beta1, platelet-derived growth factor (PDGF)-beta, epidermal growth factor receptor, metalloproteinase (MMP)-9, fibronectin, and tenascin. A down-regulation of MMP-1 gene expression was observed exclusively in BEAS-2B cells. Cationic protein-induced transcriptional effects were followed by the release of endothelin-1, PDGF-AB in the supernatants by ELISA, and by a down- and up-regulation, respectively, in the levels of MMP-1 and MMP-9 in cell lysates, by Western blot. Cell stimulation with the synthetic polycation, poly-L-arginine, reproduced some but not all effects of MBP and EPO. Finally, simultaneous cell incubation with the polyanion molecules, poly-L-glutamic acid or heparin, restored MMP-1 gene expression but incompletely inhibited MBP- and EPO-induced transcriptional effects as well as endothelin-1 and PDGF-AB release, suggesting that cationic proteins act partially through their cationic charge. We conclude that eosinophil-derived cationic proteins are able to stimulate bronchial epithelium to synthesize factors that influence the number and behavior of structural cells and modify extracellular matrix composition and turnover.

Reconstitution of full-round uridine-deletion RNA editing with three recombinant proteins

Uridine (U)-insertion/deletion RNA editing in trypanosome mitochondria involves an initial cleavage of the preedited mRNA at specific sites determined by the annealing of partially complementary guide RNAs. An involvement of two RNase III-containing core editing complex (L-complex) proteins, MP90 (KREPB1) and MP61 (KREPB3) in, respectively, U-deletion and U-insertion editing, has been suggested, but these putative enzymes have not been characterized or expressed in active form. Recombinant MP90 proteins from Trypanosoma brucei and Leishmania major were expressed in insect cells and cytosol of Leishmania tarentolae, respectively. These proteins were active in specifically cleaving a model U-deletion site and not a U-insertion site. Deletion or mutation of the RNase III motif abolished this activity. Full-round guide RNA (gRNA)-mediated in vitro U-deletion editing was reconstituted by a mixture of recombinant MP90 and recombinant RNA editing exonuclease I from L. major, and recombinant RNA editing RNA ligase 1 from L. tarentolae. MP90 is designated REN1, for RNA-editing nuclease 1.

Airway inflammation and cellular stress in noneosinophilic atopic asthma

STUDY OBJECTIVES

It has been suggested that patients with noneosinophilic asthma (NEA) show increased numbers of sputum neutrophils and a lack of response to therapy with corticosteroids, which are features that are commonly related to COPD. The aim of our study was to test the hypothesis that airway inflammation in NEA patients is different from that seen in patients with eosinophilic asthma (EA) and is similar to COPD.

DESIGN

Sputum cellular stress markers and neutrophilic and eosinophilic fluid-phase mediators were analyzed in asthma and COPD patients. NEA patients were identified based on a sputum eosinophil count of < or = 2.2% of the total nonsquamous cell count, and were compared to EA and COPD patients.

SETTING

University Hospital of Heraklion, Department of Thoracic Medicine.

PATIENTS

A total of 37 atopic asthmatic patients and 25 patients with COPD.

MEASUREMENTS

Sputum cell counts, cellular expression of heme oxygenase-1, inducible nitric oxide synthase, and nitrotyrosine, and sputum levels of eosinophilic cationic protein (ECP), myeloperoxidase (MPO), interleukin-8, and granulocyte macrophage colony-stimulating factor.

RESULTS

A total of 17 asthmatic patients (46%) belonged to the NEA group and 20 patients (54%) to the EA group. Patients with NEA showed no difference in neutrophil counts, fluid-phase mediators, or cellular stress markers compared to patients with EA. Compared to COPD patients, NEA patients showed the following significant differences: lower total cell counts (p < 0.03); lower neutrophil counts (p < 0.01); lower nitrotyrosine positive cell counts (p < 0.003); lower ECP levels (p < 0.005); lower MPO levels (p < 0.000); higher lymphocyte counts (p < 0.01); and higher macrophage counts (p < 0.03).

CONCLUSIONS

Despite low eosinophil counts, airway inflammation in NEA patients may share common features with that in EA patients but is distinct from COPD. Larger studies are needed to investigate further the clinical and inflammatory characteristics of NEA before we are able to categorize asthma patients into those with or without eosinophilic inflammation.

Eosinophil activity in Schistosoma mansoni infections in vivo and in vitro in relation to plasma cytokine profile pre- and posttreatment with praziquantel

Eosinophil activity in vivo and in vitro was studied in relation to infection intensities and plasma cytokine profiles of 51 Schistosoma mansoni-infected Ugandan fishermen before treatment and 24 h and 3 weeks posttreatment. Blood eosinophil numbers significantly declined 24 h posttreatment, but significant eosinophilia had developed by 3 weeks posttreatment. Cellular eosinophil cationic protein (ECP) content increased significantly during the transient eosinopenia but was significantly reduced 3 weeks later. No similar reduction in cellular eosinophil protein X (EPX) content was seen. Before treatment, S. mansoni infection intensity was positively correlated with 24-h boosts in plasma interleukin-5 (IL-5) and IL-6 levels, which were in turn negatively correlated with the posttreatment fall in eosinophil numbers. Significant correlations were observed between pretreatment infection intensities and plasma IL-10 and eotaxin levels. Treatment induced significant fluctuations in plasma IL-5, IL-6, IL-10, tumor necrosis factor alpha (TNF-alpha), and eotaxin levels. Optimal relative release of ECP and EPX in vitro was detected in S. mansoni soluble egg antigen-stimulated cultures during transient eosinopenia. Our data suggest that blood eosinophils are activated during S. mansoni infection and that treatment induces a burst in released antigens, causing increased production of IL-5, IL-6, IL-10, and eotaxin; a drop in TNF-alpha levels; and a transient sequestration of eosinophils, which leaves fewer degranulated eosinophils in the circulation 24 h posttreatment, followed by the development of eosinophilia 3 weeks later. During these events, it appears that preferential release of ECP occurs in vivo. Moreover, it is possible that infection intensity-dependent levels of plasma IL-10 may be involved in the prevention of treatment-induced anaphylactic reactions.