β-Glucan plus LPS promote neutrophilic inflammation in OVA-induced allergic inflammation.

(A) Timeline for OVA i.p. sensitizations (25 μg in 1 mg alum) and i.t. challenges (10 μg) with the combination of OVA, β-glucan (1x10⁷ particles) and LPS (100 ng), as indicated. (B) Airway inflammation in challenged C57BL/6 mice showing the number of total leukocytes, eosinophils (Siglec-F^hiGr-1^loCD11c^lo), neutrophils (Gr-1^hiCD11b^hiF4/80^lo), inflammatory macrophage/monocytes (F4/80^hiCD11b^hiGr-1^lo) and T cells (CD3^hiCD4^hi). (C) Total serum IgE levels in challenged mice, as indicated. (D) Pulmonary cytokine concentrations in BALF of challenged C57BL/6 mice, as indicated. (E) Numbers of recruited neutrophils in the BALF of challenged C57BL/6 wild type, Dectin-1^-/- and TLR-4^-/- mice, as indicated. (F) H&E and PAS stains of formalin fixed lung sections (left) from C57BL/6 wild type mice, challenged as indicated. Scale bars represent 100 μm (H&E) and 50 μm (PAS). Quantification (right) of mucus producing goblet cell area in PAS stained sections. (G) Airway resistance (R) in intubated C57BL/6 wild type mice exposed to increasing doses of nebulised methacholine (MCh), as indicated. *p<0.05, n.s., not significant. Shown are the mean ± SEM of pooled data from at least 2 independent experiments (n = 14–16 mice/group).