PPE-induced emphysema combined with low-dose LPS administration induces chronic low-grade pulmonary inflammation, without affecting emphysema.

<p>After intratracheal instillation of vehicle or PPE (30 µg/mouse) in <i>E3L</i> mice, low-dose intranasal LPS (1 µg/mouse) or vehicle was administered during 20 weeks WTD feeding. Total respiratory amplitude was analyzed at 8 and 18 weeks (C and D) after PPE. After sacrifice, mean linear intercept (A) and air/tissue ratio (B) were determined and inflammatory cell influx was determined by immunohistochemical staining of macrophages with F4/80 (E) and neutrophils with MPO (F). Significant effects detected by two-way ANOVA analysis are shown as p-value in textboxes above the figure. Values are presented as means ± SEM; n = 10–15; *p<0.05, **p<0.01, ***p<0.001.