Fig 2: Loss of IL31RA attenuates AHR but not inflammation and goblet cell hyperplasia during SEA-induced allergic asthma.(A) Schemata of SEA-induced allergic asthma model. (B and C) Quantification of IL-31RA and IL-31 transcripts in the lungs of wild-type and IL-31RA-/- mice treated with house dust mite (HDM) or saline. Data shown as mean ± SEM, n = 5–6/group, one-way ANOVA test, *p < 0.05. (D) Measurement of resistance with increasing doses of methacholine (MCh) in wild-type and IL-31RA-/- mice treated with saline or HDM using FlexiVent. Data are shown as mean ± SEM, n = 5–6/group. The above data is representative of two independent experiments with similar results. A two-way ANOVA test for multiple comparisons was used. * p<0.01. (E) Representative images of hematoxylin and eosin-stained lung sections from wild-type and IL-31RA-/- mice treated with saline or SEA. Images were taken at 20x magnification, scale bar 100 µm. (F) Representative images of alcian blue periodic acid shiff staining of lung sections from wild-type and IL-31RA-/- mice treated with saline or SEA. Images were taken at 20x magnification, scale bar 100 µm.

Fig 3: Loss of IL31RA has no effect on house dust mite (HDM)-induced airway inflammation and goblet cell hyperplasia.(A) Representative images of hematoxylin and eosin -stained lung sections from wild-type and IL-31RA-/- mice treated with saline or HDM. Images were taken at 20x magnification, scale bar 100 µm. (B and C) Total bronchoalveolar lavage (BAL) cell number and the differential cell count of BAL cells of wild-type and IL-31RA-/- mice treated with saline or HDM. Eos, eosinophils; Mac, macrophages; Lym, lymphocytes; and Neu, neutrophils. (D) Representative images of alcian blue periodic acid shiff(ABPAS) staining of lung sections from wild-type and IL-31RA-/- mice treated with saline or HDM. Images were taken at 20x magnification, scale bar 100 µm. (E) The percent of ABPAS-positive cells normalized to total cell in the airways of wild-type and IL-31RA-/- mice treated with saline or HDM. Data are shown as means ± SEM. One-way ANOVA was used, with n = 7–8/group. * p < 0.05.

Fig 4: Th2 cytokines upregulate IL-31RA to induce AHR with no effect on inflammation and goblet cell hyperplasia.(A and B) Quantification of IL-31RA transcripts in mouse airway smooth muscle cells (ASMC) treated with increasing doses of IL-4 and IL-13 for 16 h. One-way ANOVA test was used, n = 3/group; * p<0.05. (C) Wild-type and IL-31RA-/- mice were treated intratracheally with IL-13 on days D0 and D6 and resistance in the lungs was measured with increasing doses of methacholine (MCh) using FexiVent. Data are shown as mean ± SEM, n=4/group. Two-way ANOVA test was used, *p<0.05. (D) ASMC isolated from wild-type and IL-31RA-/- mice were seeded into collagen gels and treated with IL-13 to measure the contraction of collagen gels after 48 hours. Two-tailed Student’s t-test was used, n=3/group; * p<0.05. (E) Representative images of hematoxylin and eosin -stained lung sections from wild-type and IL-31RA-/- mice treated with IL-13. Images were captured at 20x magnification, scale bar 100 µm. (F, G and H) Quantification of inflammatory chemokines (CCL11, CCL24 and IL-17), Th2 cytokines (IL-4 and IL-5), and Th2 response-associated genes (ARG1, CHl3L3, and FIZZ1) in the whole lungs of wild-type and IL-31RA-/- mice treated with IL-13. Data are shown as mean ± SEM, n=4/group, Two-tailed Student’s t-test was used and no statistical significance observed between groups. (I) Representative images of alcian blue periodic acid shiff stained lung sections from wild-type and IL-31RA-/- mice treated with IL-13. Images were captured at 20x magnification, scale bar 100 µm. (J) Quantification of goblet cell hyperplasia associated genes including GOB5 and MUC5AC transcript levels in the total lungs of wild-type and IL-31RA-/- mice treated with IL-13. Data are shown as means ± SEM, n=4/group, Two-tailed Student’s t-test was used and no statistical significance observed between groups.

Fig 5: Loss of IL-31RA has no effect on Th2 responses and goblet cell hyperplasia during house dust mite (HDM)-induced allergic asthma.(A) Quantification of Th2 cytokine transcripts including IL-4, IL5, and IL-13 in the whole lung tissue of wild-type and IL-31RA-/- mice treated with saline or HDM using RT-PCR. (B) Quantification of chemokines and inflammatory cytokines including CCL11, CCL24, and IL-10 in the whole lungs of wild-type and IL-31RA-/- mice treated with saline or HDM using RT-PCR. (C) Quantification of Th2 response-associated gene transcripts including CHI3L3, ARG1, and FIZZ1 in the total lungs of wild-type and IL-31RA-/- mice treated with saline or HDM using RT-PCR. (D) Quantification of GOB5 and MUC5AC gene transcripts in the whole lungs of wild-type and IL-31RA-/- mice treated with saline or HDM using RT-PCR. Data are shown as mean ± SEM and representative of two independent experiments with n=5–6/group. One-way ANOVA was used. * p < 0.05.