Flurane

The experimental allergen sensitization and exposure model utilized in this study has been previously described in detail [13 (link)] and is summarized in Fig 1. Briefly, mice were sensitized twice (Day 1 and Day 6) intraperitoneally (i.p.) with 8 μg chicken ovalbumin (OVA, Sigma-Aldrich, St Louis, MO, USA) bound to 4 mg aluminum hydroxide (Sigma-Aldrich) in phosphate buffered saline (PBS). On Day 14, mice were briefly anesthetized using isoFlurane (Flurane^®, Baxter, Deerfield, Ill, USA) and split in two groups; the exposure (OVA/OVA) received an intranasal (i.n.) administration of 100 μg OVA in 25 μl of PBS on five consecutive days, while the control (OVA/PBS) group received only PBS. In another set of experiments designed to evaluate the role of BAFF, OVA sensitized mice received i.n. instillations of BAFF-R-Ig fusion chimeric protein (7 μg; R&D Systems, Abingdon, UK), which binds to its receptor (BAFFR) and blocks its action [14 (link)], or its control protein, one hour prior to OVA exposure on five consecutive days, as indicated by green arrows (Fig 1).

Allergic airway inflammation was induced in overweight and morbid obesity mouse models at 13 or 24 weeks of age. The animals were sensitized twice (Day 1 and Day 6) by intraperitoneal injections of 8 μg of ovalbumin (OVA; Sigma-Aldrich, St Louis, MO, USA) bound to 4 mg of aluminum hydroxide (Sigma-Aldrich) in 0.25 mL of sterile PBS. Acute allergic inflammation was induced by five consecutive intranasal challenges of OVA (Day 14 to Day 18). At each challenge, obese animals were briefly anesthetized using isoflurane (Flurane^®, Baxter, Deerfield, IL, USA), and 100 μg of OVA was administrated in 25 μL of sterile PBS. During the induction of allergic inflammation, DIO mice were maintained on a HFD up to 15 weeks (overweight model) and 26 weeks (morbid obesity model) of age. Age-matched DIO non-sensitized mice were used as naïve controls [35 (link)].