FIG 5.

The IRE1 and ATF6 pathways did not suppress TGEV infection. (A, B, C, and D) ST cells were transfected for 24 h with siRNA duplexes that target IRE1 and then challenged with TGEV. (A) At 24 hpi, Western blotting was performed to detect IRE1 and TGEV N. (B and C) XBP1 mRNA splicing and mRNA expression of the ERdj4 gene in IRE1 knockdown cells were determined. (D) Virus titers. (E, F, and G) ST cells were treated with different concentrations of 4μ8c, followed by infection with TGEV H87. Cells were harvested at 24 hpi and subjected to XBP1 splicing assay and Western blotting using antibodies against TGEV N protein, and the virus titers were calculated. (H and I) ST cells were transiently transfected with the HA-XBP1s-expressing plasmid and the empty vector pCAGGS-HA for 24 h and then infected with TGEV H87 at an MOI of 1. At 24 hpi, Western blotting was performed to detect HA and TGEV N, and the virus titers were calculated. (J and K) ST cells were transfected with siRNA of ATF6 for 24 h, 36 h, and 48 h and then infected with TGEV H87. At 24 hpi, Western blotting was performed using antibodies against ATF6 and TGEV N protein, and the virus titers were calculated. Means and SD of the results from three independent experiments are shown. *, P < 0.05; **, P < 0.01; ***, P < 0.001.