Fig. 5

Effect of PI3Kδ inhibition (PI-3065), cysteinyl leukotriene receptor 1 antagonism (montelukast) and anti-IL5 neutralizing antibody on the inflammatory response evoked by HDM re-challenge. All myeloid subsets (eosinophils) were analysed at 24 h post HDM re-challenge, while all lymphoid subsets (ILC2, CD4⁺ subsets and B cells) were analysed at the 3 day time-point. A Infiltration of lymphocyte subsets (CD4⁺, T regulatory cells and CD19⁺ B cells) was inhibited by PI-3065 but not montelukast. B Cytokines were analysed at 4 h post HDM re-challenge, except for IL5 which was analysed at 24 h post HDM re-challenge. PI-3065 inhibited the induction of cytokines in BAL whereas montelukast was not able to significantly inhibit any of the cytokines investigated. Data expressed as percentage inhibition. C PI-3065 and anti-IL5 antibody inhibited the infiltration of eosinophils including the inflammatory subset expressing high levels of Siglec-F into inflamed airways. However, only PI-3065 inhibited the infiltration of ILC2 and TH2 cells, whereas montelukast and anti-IL5 antibody did not significantly inhibit infiltration of these important cell types. (n = 3–6 per group for saline controls and 6–11 for HDM re-challenged groups). ^#p < 0.05, ^##p < 0.01, ^###p < 0.001, compared to vehicle + saline control group. A one-way analysis of variance (ANOVA) with Dunnets p value adjustment was used to analyse the data for significance.*p < 0.05, **p < 0.01, ***p < 0.001, compared to vehicle + HDM re-challenged group. ^$$$p < 0.001, compared to isotype control + HDM re-challenged group. Non-significant result is indicated by NS