Figure 4. TRAIL expression following i.t. LPS.

Lung sections 48 h after i.t. instillation of saline (control) or LPS were immunostained for TRAIL. (A) Lung section demonstrating lack of positive TRAIL staining in the airways of a WT mouse following saline administration. TRAIL staining is identified only where associated with small pulmonary arteries. (B) Lung section demonstrating TRAIL expression principally in the bronchial epithelium following LPS challenge of WT mice, with occasional staining of alveolar macrophages. (C) Lung section demonstrating absence of specific TRAIL staining in a TRAIL-deficient lung (negative control). These sections are representative of multiple sections cut in a minimum of three experiments. All images, 200× original magnification; scale bar represents 100 μm.