Evaluation of airway hyperreactivity in interleukin-5 transgenic mice.

Interleukin-5 (IL-5) transgenic mice constitutively produce IL-5 and show massive eosinophilia in peripheral blood as well as infiltration of eosinophils into various tissues. This study investigated whether airway hyperreactivity occurs in the airways of IL-5 transgenic mice. These mice showed marked eosinophilia in bronchoalveolar lavage fluid, but no increase in reactivity to acetylcholine. IL-5 transgenic mice actively sensitized with ovalbumin displayed more profound airway hyperreactivity in response to acetylcholine 24 h after inhalation challenge with ovalbumin. Wild-type mice treated the same way showed little, if any, airway hyperreactivity. These findings indicate that this mouse model of airway hyperreactivity is useful in understanding the mechanism underlying pulmonary eosinophilia and the consequent inflammation.