Table 1 Lung histology results demonstrating alveolar collapse, the contraction index, mucus score, tissue cellularity, collagen fiber content, and α–smooth muscle actin (n = 8 mice per group).

GroupsAlveolar
collapse (%)		Contraction
index		Mucus scoreTissue cellularity (%)Collagen fibers (%)α–smooth muscle actin (%)
MNPMNAirwaysAlveolar
septa		Alveolar
duct		Terminal
bronchiole
CTRL-SAL3.3 ± 1.52.6 ± 0.070.0 ± 0.029.6 ± 3.01.2 ± 0.613.1 ± 4.01.7 ± 1.21.8 ± 0.42.0 ± 1.0
OVA-SAL25.9 ± 1.9*3.6 ± 0.2*2.7 ± 0.6*23.9 ± 2.3*12.1 ± 2.0*36.8 ± 18.4*5.8 ± 2.8*8.6 ± 2.8*10.1 ± 2.2*
OVA-THY5.0 ± 1.2†2.3 ± 0.4†0.6 ± 0.4†24.3 ± 2.22.0 ± 0.7†13.0 ± 3.2†2.1 ± 1.6†4.7 ± 1.9†5.2 ± 1.6†

CTRL-SAL, mice sensitized and challenged with saline, intratracheally treated with saline on day 47 and sacrificed on day 67; OVA-SAL, mice sensitized and challenged with OVA, intratracheally treated with saline on day 47 and sacrificed on day 67; OVA-THY, mice sensitized and challenged with OVA, intratracheally treated with thymulin-expressing nanoparticles (50 μg of plasmids/50 μl) on day 47 and sacrificed on day 67; MN, mononuclear cells; PMN, polymorphonuclear cells.

*Statistically significant difference (P < 0.05) compared to the CTRL-SAL group.

†Statistically significant difference (P < 0.05) compared to the OVA-SAL group.