Quantitative expression of osteopontin in nasal mucosa of patients with allergic rhinitis: effects of pollen exposure and nasal glucocorticoid treatment

<p>Abstract</p> <p>Background</p> <p>Osteopontin (OPN) is a multifunctional cytokine that has been primarily investigated in Th1 diseases. Recently, it has also been implicated in Th2-mediated allergic diseases, such as asthma. The expression of OPN in allergic rhinitis (AR) is currently unknown, as is the effect of intranasal glucocorticosteroids (GCs) on that expression.</p> <p>Methods</p> <p>Subjects with AR were randomised to receive treatment with fluticasone propionate (FP) (n = 12) or a placebo (n = 16) over the grass pollen season and nasal biopsies were taken prior to, and during the season. OPN expression in the nasal mucosa was examined with immunohistochemistry. Healthy non-AR controls (n = 5) were used as a comparator.</p> <p>Results</p> <p>OPN expression was detected in epithelial cells, subepithelial infiltrating/inflammatory cells and cells lining the vessels and glands of all subjects. Comparison of the pre- and peak-pollen season biopsy sections in placebo treated patients revealed no increase in OPN expression during the grass pollen season (5.7% vs 6.4%). Treatment with a local glucocorticosteroid did not alter the expression of OPN during pollen exposure (6.2% vs 6.7%).</p> <p>Conclusion</p> <p>OPN has been increasingly associated with the pathogenesis of various Th2-mediated diseases. However, our finding that the OPN expression in the nasal mucosa of AR patients is not significantly affected by allergen exposure and is comparable to that of the healthy controls, suggests that intracellular OPN is not directly involved in the pathogenesis of allergic rhinitis.</p

Expansion of CD4+CD25+ and CD25- T-Bet, GATA-3, Foxp3 and RORγt Cells in Allergic Inflammation, Local Lung Distribution and Chemokine Gene Expression

Allergic asthma is associated with airway eosinophilia, which is regulated by different T-effector cells. T cells express transcription factors T-bet, GATA-3, RORγt and Foxp3, representing Th1, Th2, Th17 and Treg cells respectively. No study has directly determined the relative presence of each of these T cell subsets concomitantly in a model of allergic airway inflammation. In this study we determined the degree of expansion of these T cell subsets, in the lungs of allergen challenged mice. Cell proliferation was determined by incorporation of 5-bromo-2′-deoxyuridine (BrdU) together with 7-aminoactnomycin (7-AAD). The immunohistochemical localisation of T cells in the lung microenvironments was also quantified. Local expression of cytokines, chemokines and receptor genes was measured using real-time RT-PCR array analysis in tissue sections isolated by laser microdissection and pressure catapulting technology. Allergen exposure increased the numbers of T-bet+, GATA-3+, RORγt+ and Foxp3+ cells in CD4+CD25+ and CD4+CD25- T cells, with the greatest expansion of GATA-3+ cells. The majority of CD4+CD25+ T-bet+, GATA-3+, RORγt+ and Foxp3+ cells had incorporated BrdU and underwent proliferation during allergen exposure. Allergen exposure led to the accumulation of T-bet+, GATA-3+ and Foxp3+ cells in peribronchial and alveolar tissue, GATA-3+ and Foxp3+ cells in perivascular tissue, and RORγt+ cells in alveolar tissue. A total of 28 cytokines, chemokines and receptor genes were altered more than 3 fold upon allergen exposure, with expression of half of the genes claimed in all three microenvironments. Our study shows that allergen exposure affects all T effector cells in lung, with a dominant of Th2 cells, but with different local cell distribution, probably due to a distinguished local inflammatory milieu

The Effects of Tobacco Smoke on the Lymphocyte Recruiting Cytokine Interleukin-16

Background: There is an increased number of CD8+ cells in the airways in chronic obstructive pulmonary disease (COPD) and also an increased number of CD4+ cells in severe COPD. The CD4 cell chemoattractant interleukin (IL)-16 is also increased in the airways of tobacco smokers. In this thesis, we re-evaluated whether there is a local increase in IL-16 and determined whether there are systemic IL-16 alterations. We also investigated whether tobacco smoke causes a release of IL-16 in CD8+ cells and elucidated cellular mechanisms. Methods: We measured extracellular IL-16 protein (bronchoalveolar lavage fluid, BALF; plasma and serum), intracellular IL-16 protein (BAL CD8+ cells) and IL-16 mRNA (BAL cells) in long-term tobacco smokers. In occasional tobacco smokers, we analysed extracellular IL-16 protein (BALF). IL-16 protein in tonsils of tobacco smokers was assessed. For the in vitro studies, isolated human blood CD8+ cells were cultivated with and without water-soluble tobacco smoke components (CSE), an oxygen free radical (OFR) scavenger (glutathione) or a non-selective phosphodiesterase inhibitor (aminophylline) and analysed for extra- and intracellular IL-16 protein and IL-16 mRNA. Protein oxidation in CSE-treated CD8+ cells was also measured. Results: In long-term tobacco smokers, we confirmed an increase in IL-16 protein in BALF. We revealed a decrease in intracellular IL-16 protein in CD8+ cells as well as in IL16 mRNA in BAL cells. We found no corresponding impact on IL-16 protein in plasma or serum. In contrast, occasional smokers did not exhibit any substantial alteration in IL-16 protein in BALF. However, tobacco smokers were found to have a decrease in IL-16 in tonsils. In cell culture of CD8+ cells, CSE caused a release of IL-16 protein and a decrease in both intracellular IL-16 protein and IL-16 mRNA. These alterations were prevented by glutathione but not by aminophylline. CSE-treated CD8+ cells exhibited a marked increase in oxidized proteins. Conclusion: Tobacco smoke mainly exerts an effect on IL-16 release locally in the airways. CD8+ cells constitute a source of IL-16 and tobacco smoke depletes these cells by causing an extracellular release of this protein and a decrease in its mRNA. OFRs are involved as mediators of these effects

Correlation of switching volume with magnetic properties, microstructure, and media noise in CoCr(Pt)Ta thin films

The technique of field sweep-rate dependence of coercivity together with the delta-M curves, transmission electron microscopy, and media noise measurement have been employed to reveal the correlation among the magnetic switching volume, physical grain size, intergrain interaction, and noise properties. The switching volume for both CoCrTa and CoCrPtTa films was found to be ~ 15 nm in diameter, and weakly dependent on grain size and coercivity for the systems studied. In films with physical grain size larger than the switching volume, strong intergrain interaction and high media noise is observed. In films with the physical grain size close to the switching volume, smaller interactions and lower media noise is found. It is argued that a change of the grain size results in a change in the nature of the magnetic interactions