Induced Tolerogenic Dendritic Cells as Modulators of Allergic Asthma

On the first bronchoscopy day,BAL will first be performed in the lingual without instillation of diluent or allergen. A 2ml aliquot of isotonic diluent is instilled into the right upper lobe.The procedure is repeated in the right middle lobe with instillation of 2ml of standardized cat or mite allergen solution. A test dose concentration of allergen is administered first consisting of 2 ml of allergen at 1/10th(Cat,D.farinae)or 1/30th(D.pteronyssinus)the threshold concentration.If on visual inspection through the bronchoscope there is no evidence of mucosal inflammation after 2 minutes a second segmental allergen challenge will be done in the right middle lobe using 2ml of full-dose allergen at the threshold concentration(Cat,D.farinae)or 1/3 the threshold concentration(D.pteronyssinus). This dose will be predetermined by quantitative skin prick testing.A second bronchoscopy is performed 24 hours after delivery of allergen extract and diluent to obtain BAL fluid from the RUL and RML.

200 (40 teaspoons) ml of blood will be obtained from the subjects to collect different leukocyte populations. A second 200 ml of blood will be obtained from the Track 2 subjects 4 weeks later for isolation of T lymphocytes for functional studies.