Understanding Lung Deposition of Alpha-1 Antitrypsin in Acute Experimental Mouse Lung Injury Model Using Fluorescence Microscopy

Figure 4

IHC using antibody 7/4 to localize neutrophils in lung sections. The numbers and patterns of distribution of Ab7/4-positive neutrophils are demonstrated through localization of the brown chromogen diaminobenzidine (DAB). (a) Lung sections (, 5 animals per group) following single IT or IV administration of PBS, 5 or 30 mg/kg of rAAT to ALI-induced mice. (b) (A) Section of lung from the naïve mouse group (no LPS/fMLP). Arrows identify individual Ab7/4-positive cells (brown DAB chromogen) within alveolar walls. (B) Section of lung from rAAT 30 mg/kg IV group after LPS/fMLP insult, showing interface (arrows) between regions of moderate and marked numbers of Ab7/4-positive neutrophils. (C) Section of lung from PBS group LPS/fMLP, showing Ab7/4-positive neutrophils in airways (arrow) and dense foci of Ab7/4-positive neutrophils adjacent to airways (arrowhead). (D) Section of lung from rAAT 30 mg/kg IT group after LPS/fMLP administration, showing Ab7/4-positive neutrophils transmigrating across respiratory epithelium lining large airway. (c) Quantitative IHC (QIHC) for Ab7/4-positive neutrophils in lung sections following single IT or IV administration of 5 or 30 mg/kg of rAAT to ALI-induced mice.

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