Overexpression of IκBα-reduced NF-κB activity. Delivery of the adeno-associated viral vector encoding IκBβ resulted in a dose-dependent increase in lung homogenate IκBβ FLAG mRNA expression (A) and IκBβ protein concentrations, as demonstrated by the representative Western blot (B), and by densitometry of Western blots (n = 3 per group) (C). IκBβ decreased Escherichia coli-induced nuclear accumulation of the activated P65 subunit of NF-κB (D). Vehicle, animals that received intratracheal vehicle alone; IκBβ 5 × 109, animals that received 5 × 109 AAV6 particles encoding IκBβ; IκBβ 1 × 1010, animals that received 1 × 1010 AAV6 particles encoding IκBβ; IκBβ 5 × 1010, animals that received 5 × 1010 AAV6 particles encoding IκBβ. *Significantly different from vehicle group (P < 0.05, ANOVA).