Fig. 4

Regulatory role of IL-1β at exacerbation in IL-33 induction in lung tissue. mRNA expression of IL-25 (a), TSLP (b) and IL-33 (c) was analysed in lung tissue homogenates by RT-qPCR. The relative gene expression was related to the reference gene 18S and normalised to the fold change of HDM/Saline control. The staining of IL-33 protein by immunohistochemistry was quantified and presented as positivity in tissue area (d), also IL-33 stained representative photos shown for each treatment group (e). Scale bar indicates 100 μm for all four micrograph images. Data are presented as mean ± SEM, n = 4–8 mice in each group. ## = p < 0.01 compared to respective HDM/Saline control and # = p < 0.05 compared to respective HDM/Saline control. The comparison between WT and IL-1β^−/− at exacerbation is indicated by ** = p < 0.01