Online Data Supplement: Epithelial interleukin-25 is a key mediator in Th2-high, corticosteroid-responsive asthma Dan Cheng, Zheng Xue, Lingling Yi, Huimin Shi, Kan Zhang, Xiaorong Huo, Luke R. Bonser, Jianping Zhao, Yongjian Xu, David J. Erle, and Guohua Zhen Supplementary Methods Biopsy Technique We brushed 10 sites within the subsegmental bronchi of right middle and lower lobes (10 gentle upward and downward strokes per site). We used forceps to biopsy left lower lobe carinae and fixed samples in polyoxymethylene. Histology and immunohistochemistry We stained 2 μm sections with hematoxylin and eosin (HE) or polyclonal rabbit anti-human IL-25 antibody (Abgent Biotech, China). Observers who were blinded to the clinical status of the subjects counted numbers of eosinophils/mm 2 submucosa and IL-25 positive cells/mm 2 epithelium, and calculated basement membrane thickness (BMT). We used the mean of 50 measurements taken over a distance of at least 1 mm to calculate BMT as previously described (1). Dual Immunofluorescent Staining Sections of bronchial biopsy were deparaffinized with xylene, followed by rehydration by immersing in 90, 70, and 50% ethanol, water, PBS. The sections were
permeabilized in PBS with 0.3% Triton X100. The sections were then incubated with mouse monoclonal antibody against MUC5AC at 1:150 dilution (45M1 clone; Sigma, USA) and rabbit polyclonal antibody against MUC5B at 1:150 dilution (H-300 clone; Santa Cruz, USA) at 4 C overnight. These sections were washed with PBST, and then incubated with Alexa Fluor 488 goat anti-mouse IgG for MUC5AC and Alexa Fluor 568 goat anti-rabbit IgG for MUC5B (Life Techonologies, USA) at 1:200 dilution in PBST for 2 h at room temperature. After incubation with secondary antibodies, the sections were washed again, stained with DNA stain 4', 6-diamidino-2-phenylindole (DAPI) (Vector Laboratories, USA) at 1:300 dilution at room temperature and mounted. Dual immunofluorescent staining was examined using an Olympus BX-51 fluorescent microscope with appropriate filters (Olympus, Japan). Gene expression analysis We isolated total RNA from bronchial epithelial brushings and biopsies using TRIzol (Invitrogen, USA) and the RNeasy Micro Kit (Qiagen, USA), respectively and synthesized first-strand cdna using the PrimeScript RT reagent kit (Takara, Japan). We measured human IL-25, IL-33, TSLP, MUC5AC, MUC5B, CLCA1, POSTN, SERPINB10 in bronchial brushings and IL-17RB in biopsies using the Takara Perfect Real Time PCR kit, Takara SYBR Premix ExTaq polymerase, and an ABI Prism 7500 PCR System. The primers used are listed in Table E1. The cycle threshold (Ct) of each gene transcript was normalized to the mean Ct of β-actin and GAPDH. Fold differences were determined by the 2 - ΔΔ Ct method (2). Standardized IL-25 expression value was generated after -ΔΔCt of IL-25 were centered and scaled as previously E2
described (3). We measured plasma IL-25 by ELISA (NeoBioscience, China). E3
Supplementary References 1. Benayoun L, Druilhe A, Dombret MC, Aubier M, Pretolani M. Airway structural alterations selectively associated with severe asthma. Am J Respir Crit Care Med 2003; 167: 1360-1368. 2. Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods 2001; 25: 402-408. 3. Bhakta NR, Solberg OD, Nguyen CP, Nguyen CN, Arron JR, Fahy JV, Woodruff PG. A qpcr-based metric of Th2 airway inflammation in asthma. Clin Transl Allergy 2013; 3: 24. E4
Supplementary Figure Legends Figure E1. Bronchial expression of IL-17RB is increased in subjects with asthma. (A) IL-17RB staining in bronchial biopsies from healthy control subjects (n = 13) and subjects with asthma (n = 27) (original magnification 400). (B) Quantitation of IL-17RB stained cells in the epithelium. (C) Correlation between the numbers of IL-17RB stained cells and IL-25 stained cells in airway epithelium for healthy controls and subjects with asthma. Some subjects were not included in the analyses of IL-17RB staining because bronchial biopsies from those subjects were not adequate for immunohistochemistry due to limitations in the amount of intact tissue seen in the sections. Figure E2. Percentage of IL-25-low and IL-25-high subjects with positive skin prick tests to specific allergens. Figure E3. Bronchial epithelial POSTN transcript levels are increased in subjects with high epithelial IL-25 expression. Levels of transcripts for POSTN in bronchial brushings were determined by quantitative PCR. Values are relative to the median value for healthy controls. Figure E4. MUC5AC and MUC5B proteins in healthy controls and subjects with IL-25 low and IL-25 high asthma. Representative images of immunofluorescent staining for MUC5AC (green), MUC5B (red) and DAPI nuclear staining (blue) in E5
bronchial biopsies (original magnification 200). Figure E5. Sensitivity and specificity of biomarkers for ICS responsiveness. Receiver operating characteristic curve analysis of the sensitivity and specificity of plasma IL-25, blood eosinophil numbers, sputum eosinophil percentage and biopsy eosinophil numbers for ICS responsiveness. Responsive to ICS was defined as > 7.5% improvement in FEV 1 after 8 weeks of ICS treatment. AUC, area under the curve. Figure E6. Plasma IL-25 levels are decreased after ICS treatment in subjects with IL-25-high asthma. Plasma IL-25 levels in subjects with IL-25-low asthma (A) and IL-25-high asthma (B) before and after ICS treatment for 4 weeks. E6
Supplementary Table E1 ALLERGENS USED IN SKIN PRICK TEST Allergen Cockroach Bombyx mori silk Dermatophagoides farinae Dermatophagoides pteronyssinus Cat hair Dog hair Poplar pollen Platanus hispanica pollen Mugwort pollen Ragweed pollen Alternaria Cladosponium Aspergillus Penicillum
Supplementary Table E2. PRIMERS FOR QUANTITATIVE PCR Gene Type Sequence IL-25 Forward GGCCTGTCAGTCAGTGCCCC Reverse CACAGGGGCCAAGCATCTGG IL-33 Forward GTGACGGTGTTGATGGTAAGAT Reverse AGCTCCACAGAGTGTTCCTTG TSLP Forward ATGTTCGCCATGAAAACTAAGGC Reverse GCGACGCCACAATCCTTGTA IL-17RB Forward CAGAGTGGATGCTACAACATGAT Reverse CGGAGTACCCAGCTTACATTCA MUC5AC Forward CAGCACAACCCCTGTTTCAAA Reverse GCGCACAGAGGATGACAGT MUC5B Forward GCCTACGAGGACTTCAACGTC Reverse CCTTGATGACAACACGGGTGA CLCA1 Forward ATGGCTATGAAGGCATTGTCG Reverse TGGCACATTGGGGTCGATTG POSTN Forward GACCGTGTGCTTACACAAATTG Reverse AAGTGACCGTCTCTTCCAAGG SERPINB2 Forward AGCCCAACGATGACTACTTACT Reverse ACCCAAGAGTTGATGTCCTTTCT β-actin Forward GCAAGCAGGACTATGACGAG Reverse CAAATAAAGCCATGCCAATC GAPDH Forward AAGGTGAAGGTCGGAGTCAAC Reverse GGGGTCATTGATGGCAACAATA
Supplementary Table E3. THE PERCENTAGE OF IL-25-LOW AND IL-25-HIGH ASTHMA PREDICTED BY DIFFERENT PLASMA IL-25 CUTOFFS Plasma IL-25 (pg/ml) IL-25-low (%) Plasma IL-25 (pg/ml) IL-25-high (%) 50 11/22 (50.0%) >50 19/21 (90.5%) 55 16/22 (72.7%) >55 17/21 (80.9%) 60 17/22 (77.3%) >60 12/21 (57.1%)
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