Figure 7
Germ-free (GF) Scnn1b-transgenic (Scnn1b-Tg+) mice develop lung inflammation similar to Scnn1b-Tg+ mice raised in conventional specific pathogen-free conditions. (a, b) Representative photomicrographs of left lobe main stem bronchus from 6-week-old GF Scnn1b-Tg+ mice, illustrating alveolar space enlargement, mucus obstruction, and airway inflammation. (a) Hematoxylin and eosin and (b) Alcian blue–periodic acid-Schiff stain. Bar=100 μm. (c) Representative photomicrograph of bronchoalveolar lavage (BAL) cytospin preparation from GF Scnn1b-Tg+ mice, illustrating mucus plugs (light blue), granulocytes and large/foamy macrophages (arrows). Giemsa stain, bar=20 μm. (d) Semi-quantitative histopathology scores for 10-day-old (10d, open bars) and 4-week-old (4wk, hatched bars) Scnn1b-Tg+ mice (gray) and wild-type (WT) littermates (white) raised in GF conditions, n=11 Scnn1b-Tg+ and 11 WT littermates at 10 days, n=7 Scnn1b-Tg+ and 9 WT littermates at 4 weeks of age. Student's t test **P<0.005, *P<0.05 vs. WT littermates. (e–h) Longitudinal differential BAL cell counts for GF Scnn1b-Tg+ mice (▪) and WT littermates (□). n=11 and 11 at 5 days, n=18 and 8 at 10 days, n=8 and 7 at 4–7 weeks, for GF WT and GF Scnn1b-Tg+ mice, respectively. (i) Macrophage size distribution in 4–7 week-old GF Scnn1b-Tg+ mice (▪, n=7) and WT littermates (□, n=8). Boxed regions highlight the percentage of total macrophages larger than the 90th percentile in WT mice. Student's t test **P<0.005 vs. WT littermates. BALF, bronchoalveolar lavage fluid.
