Allergen
H.scandens pollen was purchased from Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment on Allergic Diseases (Beijing, China). HSE was prepared using the extraction method previously described for Artemisia vulgarispollen[17]. Briefly,H.scandens pollen was defatted with acetone, extracted with 0.125 M ammonium bicarbonate(weight/volume=1:20), dialyzed against distilled water, then aliquoted into vials (2.15 mL/vial) and freeze-dried. Subsequently, freeze-dried HSE was diluted in phosphate-buffered saline (PBS) before use. The presence of endotoxin in the pollen and HSE was assessed using the limulus amebocyte lysate test, and the test results were qualified. The total protein concentration was determined by the Bradford method. The concentration of HSE dissolved in 200 μL PBS was 5.6 μg/μL (total protein, 1.12 mg/vial).
Experimental design