Murine Models of House Dust Mite-Induced Airway Inflammation

HDM extract (Greer Laboratories, Lenoir, NC) was re-suspended in normal saline and introduced by intranasal instillation, with the mice lightly anesthetized with 5% isoflurane, using a 20–200 µL pipette tip (Fig. 1). The acute HDM protocol used 100 µg HDM (D. pteronyssinus or D. farinae) in 50 µL saline on days 0–4 and day 11. Saline-exposed control mice received 50 µL sterile saline. The 4-week models used 10 µg or 25 µg D. pteronyssinus in 35 µL of saline. Mice were sensitized for 5 consecutive days weekly (from Monday to Fridays) for 4 weeks. The mice in the 8-week model were sensitized to 25 µg D. pteronyssinus for 5 consecutive days on week 1, followed by every other weekday (Monday, Wednesday and Friday) from weeks 2 to 8. Saline-exposed control mice in the 2-week, 4-week and 8-week models were handled in a similar fashion but were only treated with sterile saline. Evaluation of the endpoint metrics occurred 24 hours after the last HDM or saline exposure.Figure 1

Timelines for allergen exposure in the 3 different HDM models. (A) Acute 2-week model of HDM-induced airways inflammation. Mice were sensitized by intranasal instillation of 100 µg HDM in 50 µl saline or 50 µl saline alone (Control) on days 0–4 and then challenged with 100 µg HDM on day 11. (B) Chronic 4-week model of HDM-induced airways inflammation. Mice were sensitized to 10 µg or 25 µg HDM in 35 µl saline or 35 µl saline alone by intranasal instillation for 5 days/week for 4 weeks. (C) Chronic 8-week chronic model of HDM-induced airways inflammation. Mice were sensitized by intranasal instillation of 25 µg HDM in 35 µl saline or 35 µl saline for 5 days a week in week 1, and every Monday, Wednesday and Friday in weeks 2–8.