FIG 2.

EGFR activation enhances PEDV replication. (A) EGF treatment induces the phosphorylation of EGFR. IPEC-J2 and HEK293 cells were serum starved for 12 h and then incubated with 10 ng/ml EGF at 37°C for the indicated times. The cell lysates were blotted with antibodies against pEGFR, EGFR, and β-actin as indicated. (B and D) EGFR activation facilitates virus infection. IPEC-J2 (B) and HEK293 (D) cells were stimulated with 10 ng/ml EGF for 15 min. After washing, the cells were infected with mock control or PEDV for 48 h or 24 h, respectively. Total RNA was extracted from the cells, and PEDV RNA levels were assessed by quantitative RT-PCR using the primers listed in Table 1. Virus yields were determined by TCID₅₀ assay. The results are representative of three independent experiments (means and SD). *, P < 0.05. The P value was calculated using Student's t test. (C and E) EGF treatment induces EGFR activation. Cells were treated with 10 ng/ml EGF at 37°C for 15 min, and the cell lysates were blotted with antibodies as indicated.