RT Journal Article SR Electronic T1 Pulmonary Dendritic Cell Distribution and Prevalence in Guinea Pig Airways: Effect of Ovalbumin Sensitization and Challenge JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 995 OP 1004 VO 282 IS 2 A1 Lawrence, Tracey E. A1 Millecchia, Lyndell L. A1 Frazer, David G. A1 Fedan, Jeffrey S. YR 1997 UL http://jpet.aspetjournals.org/content/282/2/995.abstract AB We characterized the localization and prevalence of dendritic cells (DC) in guinea pig airways before and after s.c. sensitization and aerosol challenge with ovalbumin (OVA). DC, eosinophils, macrophages, T cells and B cells in lung and trachea were identified and quantified in frozen sections using monoclonal antibodies and computer-assisted image analysis. Airway reactivity of conscious animals to inhaled methacholine was examined. In unsensitized animals, DC were localized primarily within the lamina propria of the trachea and bronchi, in the submucosa of the trachea and in the adventitia of the bronchi. In contrast to reported studies on rats, few DC were noted in the epithelium. After OVA challenge, sensitized animals demonstrated an early obstructive response and a late-phase response that was well developed by 18 hr. Challenge with OVA increased DC prevalence in the lamina propria and submucosa of the trachea and in the lamina propria and adventitia of the bronchi. There was widespread eosinophilia throughout the airways, but no changes in B cells or T cells were evident. Macrophages were increased in the epithelium of both OVA-treated and saline-treated animals. At 18 hr after challenge, sensitized guinea pigs but not saline-treated controls were hyperreactive to inhaled methacholine. Except for macrophages, none of these effects were observed after saline treatment. Our findings indicate that inflammation in the airways of OVA-sensitized guinea pigs involves infiltration of DC, which is seen at the time animals are hyperreactive to inhaled methacholine. The American Society for Pharmacology and Experimental Therapeutics