FIGURE 5.

ER stress and RSV infection in HTBE cells. A, quantitative RT-PCR data showing induction of BiP mRNA levels by RSV infection in HTBE cells. RNA was isolated from the indicated groups (of four donors) at 48 h post infection. HPRT, hypoxanthine-guanine phosphoribosyltransferase. B, quantitative RT PCR data of spliced XBP1 mRNA. Cellular RNA was isolated from the indicated groups (of three donors) at 24 h post-infection. Tunicamycin was used at 1 μg/ml for 4 h in both A and B. C, Western blot analysis using an all-antigen polyclonal RSV antibody, detecting G, F, P, and M2-1 viral proteins, 8 h post-infection of HTBE cells with or without cotreatment with the selective IRE1 endonuclease inhibitor (inh) 3,5-dibromosalicylaldehide at 20 μm. Three representative blots are shown along with corresponding densitometry analysis from three independent experiments using cells from three different donors. The EGF receptor was probed as a control cellular transmembrane glycoprotein.