In allergic asthma, egress of total and allergen specific T lymphocytes from blood to airway lumen after allergen exposure contributes to local chronic inflamation. Here, we investigated whether in asthmatics with multiple sensitizations an allergen challenge causes a clonotypically specific, measurable blood depletion of CD4 T lymphocytes. We studied 6 asthmatic patients with multiple IgE-dependent sensitizations to inhalant allergens. Each subject underwent a control and 2 or 3 allergen challenges. Ten min before and 24 h after each challenge an in vitro assay was performed to measure the proliferation of peripheral CD4 T lymphocytes to allergens which were both sensitizing and non sensitizing in each individual, as well as to tetanus toxoid. We found that the obstructive airway response to each of the sensitizing allergens is associated with significant reduction of in vitro proliferation of CD4 T cells not only to the provoking allergen but also to the other sensitizing allergens. In contrast, proliferation to non sensitizing allergens and to tetanus toxoid do not change. This phenomenon occurs independently of the allergen used for bronchial challenge. We conclude that airway exposure to a given allergen is associated with a blood depletion of allergen specîfic-T lymphocytes which is clonotypically non specific but limited to those lymphocytes committed to respond to sensitizing allergens.
|Publication status||Published - 1996|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology