LPS-induced airway inflammation in siglec-E–deficient mice. Total and differential cell counts in (A) bronchoalveolar lavage and (B) lung tissue digests from WT mice and siglec-ER126D mice following aerosolized LPS. Values are expressed as means ± SEM; n = 4-6 per group; and *P < .05, Mann-Whitney U test compared with WT mice. (C) Paraffin-embedded lung tissue sections were stained with a specific antibody against myeloperoxidase to identify neutrophils (arrows). Scale bars represent 20 µm on images acquired with an Axioskop Zeiss microscope (63× PlanNeoFluor/1.25 objective) equipped with an Axiocam digital camera (Carl Zeiss Microscopy LLC, Thornwood, New York). Data are representative of n = 4-6 per group. (D) Eight weeks after reconstitution, radiation bone marrow chimeric mice were exposed to aerosolized LPS. One hour after LPS, cells were isolated from lung tissue digests, and numbers of neutrophils were determined by flow cytometry. Data are expressed as means ± SEM; n = 4-5 per group; and *P < .05, Mann-Whitney U test compared with mice reconstituted with WT cells. (E) Increased margination of neutrophils in the lung tissue of siglec-E–deficient mice 4 hours after 50 μg intraperitoneal LPS. Paraffin-embedded lung tissue sections were stained with a specific antibody against myeloperoxidase to identify neutrophils in the capillary bed (arrows; scale bars represent 20 µm). Neutrophils were enumerated in 10 random fields per section. Values are expressed as means ± SEM; n = 5 per group; and *P < .05, Mann-Whitney U test compared with WT mice.
