Figure 6.

(A–D) Impact of SP-D on epithelial susceptibility to P. aeruginosa traversal. Corneas of wild-type C57BL/6 (A) and SP-D^−/− (B–D) mice were tissue paper blotted before inoculation in vivo with GFP-expressing P. aeruginosa strain PAO1. Fluorescence microscopy showed that after 5 hours, bacteria had partially traversed the corneal epithelium of SP-D^−/−, but not wild-type, mice. Scale bar, 10 μm. (green) Bacteria (GFP). Blue: cell nuclei (DAPI); red: laminin (rhodamine). (E) Quantification of GFP-labeled P. aeruginosa penetration of a blotted cornea ex vivo comparing wild-type (Black Swiss) and SP-D^−/− mice. After euthanatization, eyes were enucleated, tissue paper blotted, and PBS rinsed before incubation with GFP-expressing P. aeruginosa (200 μL of a concentrated bacterial suspension approximately 10¹¹ cfu/mL). After 8 hours of exposure to bacteria, confocal microscopy showed greater bacterial traversal of the corneal epithelium in SP-D^−/− eyes (blue) compared with wild-type (gray).