Fig. 3

Induced neutrophilia in BALF and lung tissue was associated with induced chemokine expression at exacerbation in WT mice while reduced in the IL-1β^−/− mice. Airway neutrophils quantified in BALF (a) and lung tissue (b). Representative slides of immunohistochemically stained neutrophils in the lung tissue demonstrating reduced neutrophilia in IL-1β^−/− mice during exacerbation compared with WT mice (c). Scale bar in small micrographs indicate 50 μm while large micrographs scale bar is 200 μm. Levels of different neutrophil chemoattractants analysed in the lung: CXCL1 protein in BALF (d) and lung tissue mRNA (e), also lung tissue mRNA expression of TNF-α (f) and CCL5 (g). The relative gene expression was related to the reference gene 18S and normalised to the fold change of HDM/Saline control. Data are presented as mean ± SEM, n = 4–7 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 or * = p < 0.05