Fig. 3.

Rab27a and Munc13-4 are not necessary for neutrophil infiltration into the lungs during LPS-induced systemic inflammation. Neutrophil infiltration into lungs was determined by analysis of tissue-associated myeloperoxidase at 4 h (A) and 24 h (B) after intraperitoneal LPS or PBS injections. Results represent the means ± SEM (n = 5 to 7 mice per group; three independent experiments). *, P < 0.01 versus PBS (nonparametric Mann-Whitney test). (C) Representative images of immunofluorescence analysis of Ly-6G-positive cells showing neutrophil infiltration into lungs of wild-type (WT), Rab27a^ash/ash (ashen), and Munc13-4^jinx/jinx (jinx) mice 4 h after LPS but not PBS administration. (D) Immunofluorescence analysis showing P-selectin expression in alveolar capillaries from Rab27a^ash/ash mice after LPS treatment. Neutrophils, visualized by staining of endogenous MPO (red), are observed both attached to the activated endothelium (arrowheads) and after transendothelial migration (arrows). (E) Immunofluorescence analysis shows expression of ICAM-1 in alveolar walls. Specific staining is also observed in the capillary endothelium (arrowheads) but not in the bronchial epithelium (arrows). Scale bars, 35 μm (C and E), 10 μm (D).