We investigated the role of PI3Kγ in allergen-induced allergic airway inflammation, airway hyperresponsiveness (AHR), and airway remodeling with PI3Kγ-deficient mice.
After ovalbumin (OVA) sensitization, wild-type (WT) and PI3Kγ-deficient mice were exposed to aerosolized OVA 3 days per week for 5 weeks.
In OVA-sensitized and OVA-challenged (OVA/OVA) PI3Kγ-deficient mice, levels of airway inflammation, AHR, and airway remodeling were significantly decreased compared with those in OVA/OVA WT mice. On the other hand, no significant differences were detected in serum OVA-specific IgE and IgG1 levels and CD4/CD8 balance in bronchoalveolar lavage fluid between OVA/OVA WT mice and OVA/OVA PI3Kγ-deficient mice. To determine in which phase of allergic responses PI3Kγ plays a role, we transferred splenocytes from OVA-sensitized WT or PI3Kγ-deficient mice to naive mice of either genotype. Similar increased levels of eosinophils were induced in both WT recipient mice but not in both PI3Kγ-deficient recipient mice.
PI3Kγ might be involved in allergic airway inflammation, AHR, and airway remodeling by regulating the challenge/effector phase of allergic responses.