Fig. 1: Lysosomal function is enhanced during eosinophil activation in allergic airway inflammation.

A–H Eosinophils were isolated from the peripheral blood of Il5 Tg mice. A Gene Ontology (GO)-based gene set enrichment analysis (GSEA) of eosinophils treated with or without IL33 (20 ng/ml) for 8 h (Kolmogorov-Smirnov statistic, 1000 permutations, two-sided; P values adjusted by FDR). B, C Acidity of lysosomes in eosinophils treated with IL33 (20 ng/ml) for 0, 2, 4, and 8 h (n = 3 biological replicates). Scale bars, 10 μm. D Protein expression of V-ATPase H, V-ATPase D, and Cathepsin L (CTSL) in eosinophils treated with IL33 (20 ng/ml) for 0, 2, 4, and 8 h. E CTSL enzyme activity in eosinophils treated with IL33 (20 ng/ml) for 0, 2, 4, and 8 h (n = 3 biological replicates). F, G Lysosomal acidity and CTSL enzyme activity in eosinophils treated with IL33 (20 ng/ml) in the presence or absence of 0.5 µM KM91104, 10 nM Bafilomycin A1 (BafA1), 100 nM Concanamycin A (Con. A) for 8 h (n = 3 biological replicates). H Protein expression of epidermal growth factor receptor (EGFR) in eosinophils treated with or without IL33 (20 ng/ml) for 8 h, and subsequently incubated with or without EGF (100 ng/ml). I, J Lysosomal acidity and CTSL enzyme activity in eosinophils isolated from peripheral blood of patients with asthma and treated with or without IL33 (100 ng/ml) for 8 h (n = 3 biological replicates). K, L Lysosomal acidity and CTSL enzyme activity in eosinophils from lung tissues of C57BL/6 mice after house dust mite (HDM) (n = 6 biological replicates) or saline (n = 5 biological replicates) intratracheal instillation. M Representative immunofluorescence images of eosinophil peroxidase (EPX, green), CTSL (red), and nuclei (DAPI, blue) in lung tissues from HDM or saline-treated mice. Scale bars, 10 μm and 5 μm. Data presented are representative of three independent experiments and shown as mean ± SEM. Statistical analyses were calculated using one-way ANOVA with Sidak’s multiple comparisons test (B, E, F, and G) and two-sided unpaired Student’s t test (I–L).