Nasal Hypersensitivity Response in Th9-Transferred Mice

Polarized Th9 cells (2 × 10⁷) were intravenously injected in each BALB/c mouse on day 0. From 6 hours after the cell transfer, these mice were challenged with intranasal administration of 20-μL OVA (30 mg/mL; Sigma, Sigma, St. Louis, MO, USA) or phosphate buffered saline (PBS) once a day on days 0–3 (Fig. 1). NHR was assessed 6 hours after the last challenge by counting the number of sneezes for 5 minutes just after the administration of 10-μL histamine (100 mM; Nacalai tesque, Kyoto, Japan) [3 (link)]. Inflammatory cells in the nasal lavage fluid were classified by means of morphological criteria as described previously [3 (link)]. The number of transferred Th9 cells in nasal-associated lymphoid tissue (NALT) were determined by flow cytometry upon staining with anti-CD4-APC-Cy7 (BioLegend) and anti-DO11.10 T-cell receptor (TCR)-FITC (eBioscience). This procedure did not induce any inflammatory responses in the lower airways [10 (link)]. In some experiments, 10-mg/kg dexamethasone (Dex: Tokyo Kasei, Tokyo, Japan) suspended in PBS containing 0.5% Tween-20 (Sigma) was subcutaneously injected in mice 30 minutes before each OVA challenge.