Figure 6

H5N1 HA is detected by TLR4 expressed on respiratory epithelial cells, facilitating the activation of JAK3, which leads to the impairment of cAMP-dependent CFTR channels. (A) Isc and ΔIsc measurements in HA-challenged tracheal tissues of JAK3^+/+ mice with or without TLR4 inhibitor treatment (n = 5 per group, *p < 0.05 versus mice administered saline; ^#p < 0.05 versus mice pretreated with HA alone); (B) Immunofluorescent staining for phosphorylated JAK3 (p-JAK3) expression in 16HBE cells. Scale bars = 40 µm (C) Western blot for p-JAK3 in 16HBE cells. The mean optical densities of the bands for each group are presented (C, bottom) (*p < 0.05 versus saline control cells; #p < 0.05 versus cells incubated with HA alone for 60 min); c: control. (D) Quantitative RT-PCR analysis of TLR4 and CFTR gene expression in HA-treated calu-3 cells for the indicated periods compared with control.