Lung sections of mice vaccinated with OprF-pulsed DCs and infected with PAO1 strain. Histopathology at 7 days after infection. Lung sections A-B from infected mice show the involvement of bronchioles and of the alveolar space by an inflammatory infiltrate predominantly consisting of neutrophils filling most of bronchioles (red arrow: bronchial epithelium; blue arrow: neutrophilic infiltrate); the lungs sections from mice vaccinated with n-OprF-pulsed DCs (C-D) and His-OprF-pulsed DCs (E-F) show a great reduction of inflammatory cell recruitment. Lung sections were hematoxylin-eosin stained. A-C-E magnification ×10. B-D-F magnification ×40.