Fig. 5.

STAT3 overexpression enhances PEDV replication. (A) IPEC-DQ cells were pre-incubated in the absence or presence of the indicated concentrations of A77 1726 for 2 h and then infected with the HLJBY strain of PEDV by incubating the cells at 4 °C for 2 h. After rinse twice, the cells were incubated in serum-free medium and incubated at 37 °C for 30 min. Cell lysates were prepared and analyzed for JAK1, JAK2, and STAT3 tyrosine phosphorylation and the level of the N protein of PEDV by Western blot. (B) STAT3 overexpression enhances viral protein synthesis. IPEC-DQ cells were transfected with the pcDNA3.1 empty vector or the expression vector encoding STAT3. After incubation for 24 h, the cells were infected with the indicated MOI of PEDV and then incubated for 24 h. The cell lysates were prepared and analyzed for the expression of indicated proteins by Western blot. The density of the phosphorylated JAK1, JAK2, and STAT3 bands was analyzed by using NIH Image-J software and normalized by the arbitrary units of β-actin or STAT3. *p < 0.05, **p < 0.01, compared to the corresponding samples in the cells transfected with pcDNA3.1 with a Student's t-test.