with allergic asthma are characterized by aberrant immune responses to
environmental allergens leading to eosinophilic airway inflammation and
hyperresponsiveness. The activation of allergen-specific T-helper type
2 (Th2) lymphocytes, which produce a limited set of cytokines including
interleukin (IL)-4 and IL-5, plays a crucial role in the initiation and
progression of allergic asthma. Currently, glucocorticoids are the most
effective drugs in the treatment of patients with asthma to reduce the
inflammatory component and hyperresponsiveness, but they are not very
selective and patients can be refractory or become insensitive to them.
Novel drug targets that modulate or inactivate disease-inducing Th2
lymphocytes may prove to be superior and more selective. Th2
lymphocytes appear to be generated in the lung-draining lymph nodes,
after which they migrate to the lung tissue.