Hans-Peter Hauber

IL-9 in allergic inflammation.

Th2 type cytokines such as interleukin (IL)-4, IL-5, IL-9, and IL-13 are important mediators in allergic inflammation. The present review will focus on the role of IL-9 in allergic inflammation. The structure and genomic architecture of IL-9 and its receptor, the source of IL-9 and its regulation as well as its effects on different cell types will be reviewed. Furthermore, the specific role of IL-9 in allergic diseases and the potential therapeutic approach of blocking IL-9 will be discussed.

Toll Like Receptors 4 and 2 Expression in the Bronchial Mucosa of Patients with Cystic Fibrosis

BACKGROUND Cystic fibrosis (CF) is a lung disease characterized by chronic infection with Gram-negative bacteria Pseudomonas aeruginosa and Gram-positive bacteria Staphylococcus aureus. Recently, toll-like receptor (TLR) 4 has been shown to be responsible for the lipopolysaccharide (LPS)-mediated immune response. While TLR2 mediates responses driven by bacterial lipoproteins and peptidoglycans from Gram-positive bacteria, LPS derived from P aeruginosa may stimulate the immune response in the airways of patients with CF via activation of TLR4. OBJECTIVES To investigate TLR4 and TLR2 expression in the bronchial mucosa of patients with CF and normal control subjects. PATIENTS AND METHODS Endoscopic bronchial biopsies from seven patients with CF and six healthy control subjects were obtained. TLR4 and TLR2 expression was assessed using immmunocytochemistry. Real-time polymerase chain reaction was used to detect TLR4 messenger RNA in blood cells from patients with CF and to compare TLR4 expression in CF bronchial epithelial cells with non-CF bronchial epithelial cells. RESULTS In patients with CF, the number of TLR4-positive cells was significantly increased in their submucosa (P<0.05) but significantly reduced in their epithelium compared with control subjects (P<0.05). The majority of TLR4-positive cells were neutrophils. Patients with CF (n=4) and control subjects (n=4) had a similar percentage of TLR4-expressing neutrophils and monocytes/lymphocytes in peripheral blood. CF cells (IB-3) had significantly decreased basal TLR4 messenger RNA expression compared with non-CF cells (Calu-3) (P<0.05). Although there was a trend toward reduced TLR2 expression in the airway epithelium of patients with CF (P=0.07), there was no significant difference in TLR2 expression in the submucosa of patients with CF compared with that of control subjects. CONCLUSIONS Both TLR4 and TLR2 expression in the bronchial epithelium of patients with CF were significantly reduced compared with healthy control subjects. In contrast, the number of TLR4-positive neutrophils in the submucosa of patients with CF was higher than in control subjects. This may suggest that the loss of epithelial TLR expression may contribute to the impaired defense against LPS.

Mucin Overproduction in Chronic Inflammatory Lung Disease

Mucus overproduction and hypersecretion are commonly observed in chronic inflammatory lung disease. Mucins are gel-forming glycoproteins that can be stimulated by a variety of mediators. The present review addresses the mechanisms involved in the upregulation of secreted mucins. Mucin induction by neutrophil elastase, bacteria, cytokines, growth factors, smoke and cystic fibrosis transmembrane conductance regulator malfunction are also discussed.

Expression of HCLCA1 in cystic fibrosis lungs is associated with mucus overproduction

Mucus overproduction is typical in cystic fibrosis (CF) airway disease. The human calcium-activated chloride channel, hCLCA1, has been reported to be upregulated by interleukin (IL)‐9 and to regulate the expression of mucins. Therefore, the expression of IL‐9, IL‐9 receptor (IL‐9R) and hCLCA1 between the lungs of CF patients and healthy control subjects was compared. Endoscopic biopsy samples of bronchial mucosa from 10 CF patients and six control subjects were stained with periodic acid-Schiff. IL‐9, IL‐9R and hCLCA1 expression was determined by immunocytochemistry. Expression of hCLCA1 mRNA was also determined by in situ hybridisation. The present study found significant increases in IL‐9, IL‐9R and hCLCA1 immunoreactivity, hCLCA1 mRNA expression, and numbers of mucus-producing cells in the mucosa of CF patients compared to control subjects. Positive correlations were found between IL‐9R‐positive-cells with IL‐9‐positive cells and hCLCA1-positive cells, and between PAS-positive cells with hCLCA1-positive cells and IL‐9R‐positive cells. Expression of hCLCA1 mRNA was colocalised with IL‐9R expression and PAS-positive staining in epithelial cells. Increased expression of interleukin‐9 and interleukin‐9 receptor, as well as an upregulation of the human calcium-activated chloride channel, hCLCA1, in mucus-producing epithelium of cystic fibrosis patients, support the hypothesis that interleukin‐9 contributes to mucus overproduction in cystic fibrosis airway disease.

Effects of hydrofluoroalkane and dry powder- formulated corticosteroids on sputum inflammatory markers in asthmatic patients

BACKGROUND Inhaled corticosteroids are powerful drugs that can suppress airway inflammation in asthmatic patients. Deposition of most of the inhaled corticosteroid occurs mainly in the central airways. However, a new hydrofluoroalkane formulation of beclomethasone dipropionate (HFA-BDP) is preferentially deposited in the distal airways. Inflammatory characteristics of induced sputum have been shown to differ in samples collected early after sputum induction compared with later. OBJECTIVE To compare the effects of HFA-BDP and budesonide in a dry powder inhaler (DPI-BUD) on inflammatory cells and inflammatory cytokine expression in early and late induced sputa compared with placebo. METHODS Seventeen patients with mild, intermittent bronchial asthma were randomly assigned to two treatment groups: eight patients received HFA-BDP and nine patients received DPI-BUD. Each patient was treated with one of the active treatments and placebo (for four weeks), with a two-week washout interval in between. Inflammatory cells and expression of interleukin (IL)-4 and IL-5 were measured in early and late induced sputa before and after active treatment, as well as before and after placebo treatment using immunocytochemistry and in situ hybridization. RESULTS Compared with placebo, eosinophils were significantly reduced in both early and late induced sputa after HFA-BDP treatment (P<0.05), whereas DPI-BUD had a significant effect only on early induced sputum. Both HFA-BDP and DPI-BUD decreased IL-4 expression in early and late induced sputa, but the effect was more prominent with HFA-BDP. IL-5 expression was reduced in both early and late induced sputa after HFA-BDP treatment. DPI-BUD significantly decreased IL-5 expression in early but not in late induced sputum. The number of lymphocytes was not altered by either treatment. CONCLUSIONS HFA-BDP reduced eosinophilic inflammation and T helper 2-type cytokine expression in both early and late induced sputa, whereas the effect of DPI-BUD on inflammation was predominantly demonstrated in early induced sputum.

Expression of interleukin-4, interleukin-9 and interleukin-13 in peripheral blood mononuclear cells of cystic fibrosis patients with and without allergy

Bronchial hyperresponsiveness (BHR) and mucus overproduction are common in CF pulmonary disease and allergic reactions can be frequently observed in cystic fibrosis (CF) lung disease. However, the underlying pathophysiological mechanisms are far from being completely understood. Therefore the expression of the Th2 type cytokines interleukin (IL)-4, IL-9 and IL-13 in CF patients with allergy was compared to patients without allergy. Peripheral blood mononuclear cells (PBMC) samples from 9 allergic CF patients and 8 non-allergic CF patients were obtained. In situ hybridization and immunocytochemistry were performed to determine mRNA and protein expression of IL4, IL-9, and IL-13 in PBMC. PBMC from allergic CF patients expressed significantly more IL-13 mRNA and protein compared to non-allergic patients (p < 0.05). There was no significant difference for IL-4 and IL-9 between the two groups. In both groups IL-9 mRNA and protein expression were significantly higher compared to IL-4 and IL-13 expression (p < 0.05). These results suggest that IL-13 plays an important role in allergic disease in CF. Moreover, IL-9 may be important in CF disease whether allergy is present or not as it may contribute to BHR and mucus overproduction.

Rupert Timpl – A Personal Account

Accessible online at: www.karger.com/iaa The message of Rupert Timpl’s (fig. 1) untimely and unexpected death on October 20, 2003, struck me completely unprepared during a hiking tour through the Dolomites in Northern Italy, just across the Austrian border, a few miles from my hometown Innsbruck in Tyrol, Austria. It was brought to me by one of my students who hiked with our group and who had just spent a few days in Martinsried at the Max-Planck Institute for Biochemistry (MPI) near Munich, Germany, where Rupert has worked for nearly three decades – the last years as Head of the Department of Connective Tissue Research and as Acting Director of the whole MPI before his retirement in 2000. During that beautiful clear October day in the Dolomites (fig. 2) with several hours of walking time before me, the sudden confrontation with the fact that I would not see Rupert again, afforded the opportunity to immediately and intensively reflect on the role that he played both in my professional as well as in my private life. It first came to my mind that of all the associates of Rupert my own connection was the longest lasting, since it already started in 1965 when we first met in a small laboratory of a peripheral hospital, the Hanuschkrankenhaus, in Vienna. At that time, I was on my first postdoctoral position at the Institute for General and Experimental Pathology, University of Vienna, Medical School, where one of our associate professors, Carl Steffen, had a joint appointment as the head of the Central Diagnostic Laboratory of that hospital. There, Steffen had started a group of connective tissue immunologists, led by the young eager beaver Rupert, at that time still a graduate student who already had an impressive list of highly cited publications and – typically for him – also supervised three postdocs, Fig. 1. Dr. Rupert Timpl, Max-Planck-Institut für Biochemie, Martinsried.