Aspergillus-Induced Eosinophilic Esophagitis

The Jackson Laboratory (Bar Harbor, ME, USA) provided the specific pathogen-free BALB/c mice. Age- and sex-matched mice (6–8 weeks) were used in all trials. EoE was induced using similar methods as in the earlier experiments [40 (link),41 (link)]. Briefly, mice were anesthetized with a light dose of isoflurane (Iso-Flo; Abbott Laboratories, North Chicago, IL, USA), then administered 100 μg Aspergillus fumigatus (Greer Laboratories, Lenoir, NC, USA) in 50 μL normal saline (or 50 μL normal saline alone for control mice) intranasally three times weekly for three weeks while in a supine position. Animals were administered an injectable dose of CRTH2 antagonist (OC000459) (Cayman Chemical, Ann Arbor, MI, USA) every other day leading up to the final Aspergillus challenge. The mice were sacrificed 24 h after the final intranasal allergen or saline exposure. Anti-MBP immunostaining was used to examine eosinophils in esophageal tissue slices, and chloroacetate esterase labeling was used to examine mast cells, both in accordance with the previously reported techniques [31 (link),42 (link)]. Procedures involving animals were approved by the Tulane Institutional Animal Care and Use Committee and complied with the NIH regulations.