Fig. 1. Augmented airway resistance in HDM-treated lta4h^−/− mice despite reduced airway inflammation.

(A) Wild-type and lta4h^−/− mice were administered HDM or phosphate-buffered saline (PBS) intranasally three times per week for 3 weeks. (B) Schematic depicting the opposing proinflammatory (LTB₄ generation) and anti-inflammatory (PGP degradation) activities of LTA₄H. Abrogation of LTA₄H activity (red crosses) will result in reduced LTB₄ but increased PGP. (C) Airway resistance (R) to increasing doses of methacholine (Mch) was measured 24 hours after the final HDM/PBS exposure. (D) Airway resistance at 100 mg/ml methacholine. At 24 hours after final HDM/PBS exposure, total cell numbers in the BAL were assessed by trypan blue exclusion (E), and airway eosinophils (F), CD4⁺ T cells expressing T1/ST2 (G), and CD4⁺ T cells expressing IL-13 (H) were assessed by flow cytometry. Figures present combined data from two independent experiments with four to six mice per group in each experiment. Results depicted as means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, using Mann-Whitney statistical test.