*2.3. Animal Model for LPS/OVA-Induced Steroid-Resistant Neutrophilic Airway Inflammation*

Mice were anesthetized with 5% isoflurane before the treatment. Then, the mice were sensitized with 10 μg of LPS plus 75 μg of OVA in 20 μL of phosphate-buffered saline (PBS) by intranasal administration. During the challenges, 50 μg of OVA in 20 μL PBS was administered intranasally (i.n.). To test for steroid resistance, dexamethasone (1 mg/kg) was injected intraperitoneally (i.p.) 1 h before each challenge. For the inhibition experiments, 100 μL of LY255283 (10 mg/kg), baicalein (20 mg/kg), or vehicle control (mixture of 8:2 DMSO/PBS) was administered i.p. 1 h before each challenge. For the neutralization of G-CSF, an anti-G-CSF antibody (5 mg/kg) or control IgG antibody in PBS (100 μL) was injected i.p. 1 h before each challenge. Negative control (NC) mice were not injected or treated during the experiment.
