Eosinophilic leukocytes accumulate in high numbers in the lungs of asthmatic patients, and are
believed to be important in the pathogenisis of asthma. A potent eosinophil chemoattractant is
produced in the asthmatic lung. This small protein, the chemokine eotaxin, is synthesized by a number
of different cell types, and is stimulated by interleukin-4 and interleukin-13, which are produced by
T-helper (Th)2 lymphocytes. Low molecular weight compounds have been developed that can block
the eotaxin receptor C-C chemokine receptor (CCR)3, and prevent stimulation by eotaxin. This
provides the potential for orally available drugs that can prevent eosinophil recruitment into the lung
and the associated damage and dysfunction.