The long-term goals of this proposal are to determine interactive effects of atmospheric pollution and underlying airway disease on ciliated epithelial cell function. Ciliated airway epithelium is directly exposed to the atmospheric environment. Two major urban pollutants, sulfuric acid and formaldehyde, which inhibit ciliated epithelial cells, will be used as representative acid and aldehyde pollutants encountered in current urban atmosphere. Individuals with asthma are generally viewed as a pollution sensitive group of humans due to inflammatory disease of the airways. Inflammatory mediators released due to allergen inhalation affect epithelial cell function and may alter response to stress from pollutant inhalation. The hypotheses to be tested are: 1) ciliated epithelial cells from asthmatics respond differently to environmental pollutants compared to normals on the basis of stress protein (hsp) induction, and protein tyrosine phosphorylation as an indicator of signal transducing events, 2) inflammatory mediators released in allergic asthma induce ciliary dysfunction, and alter tyrosine phosphorylation of proteins, but do not induce stress proteins, 3) ciliated epithelial cells after exposure to allergen-induced inflammatory mediators are susceptible to additional stress from environmental pollutants, and 4) different environmental pollutants interact differently with underlying, inflammatory disease. To address the first hypothesis, ciliated epithelial cells will be obtained from normals and asthmatics and subjected thereupon to H2SO4 or HCHO concentrations which elicit ciliary dysfunction, confirmed by videomicroscopic image analysts. Induction of stress proteins, hsp27, hsp72/73, and hsp9O will be analysed by immunofluorescent microscopy and by western blotting technique with densitometric quantitation. Alterations in tyrosine phosphorylation of proteins will be examined by western blotting. Epithelial cells from normals and asthmatics also be cultured in a biphasic system (air/liquid interface on membrane supports) and subsequently tested by the same methods to determine if the response is inherent in the cells or reflects different conditions in vivo. Differences in -response to an acid versus an aldehyde pollutant exposure will also be compared. After specific allergen challenge in both normals and asthmatics, epithelial cells will be obtained and the experiments repeated, part of each specimen not exposed to pollutant and the rest exposed, to address the second and third hypotheses, respectively. Biphasic culture of epithelial cells obtained following allergen challenge and subsequent pollutant exposure will permit confirmation that initial differences in response after challenge are attributable to inflammatory conditions in vivo in asthmatics. These results will advance our understanding of the interplay of underlying inflammatory airway disease and environmental pollutant(s) stress-induced alterations to ciliated airway epithelial function.
