G9a-deficient mice are protected from papain and HDM-induced lung eosinophilia. (A) G9a^fl/fl and Vav.G9a^−/− mice were intranasally challenged with a short course of papain. Mice were sacrificed 24 h after the last challenge. Expression of Il5 and Il13 in lungs was measured by quantitative RT-PCR. Quantification of eosinophils in the BAL of naive and papain-treated mice as determined by flow cytometry is shown. Data are from three independent experiments (n = 4–7 per experiment). (B) Rag.G9a^fl/fl mice and Rag.Vav.G9a^−/− mice were intranasally challenged with a short course of papain. Mice were sacrificed 24 h after the last challenge. Quantification of eosinophils in the BAL was determined by flow cytometry. Data are from two independent experiments (n = 4–7 per experiment). (C) Number of ILC2s in the lungs and eosinophils in the BAL were quantified after a long course of papain. Data are from two independent experiments (n = 3–7 per experiment). (D) Numbers of ILC2s in the lung and eosinophils in the BAL were quantified after administration of HDM antigen. (E) Expression of Il5 and Il13 in lungs was measured by quantitative RT-PCR. (F) The number of PAS⁺ goblet cells per field in the large airways was enumerated. (G) PAS-stained lung sections. Bars, 100 µm. (H) IL-5 and IL-13 production by equal numbers of ILC2s purified from the lungs of G9a^fl/fl or Vav.G9a^−/− mice. The data shown are representative of four independent experiments (n = 3–6 per experiment). (D–G) Data are from three independent experiments with n = 4–9 per experiment. *, P < 0.05; Student’s t test. Errors bars indicate SEM.