Fig. 6.

Temperature shift and the effect of peptide H on cell infection by PEDV. (A) PEDV was treated with various concentrations of peptide H or with negative control peptide F at 4 °C for 1 h then used to infect Vero cells (PFU=5×10³/ml) at 4 °C. (B) PEDV (PFU=5×10³/ml), peptides H or F, and Vero cells were co-incubated at 4 °C for 1 h, washed, then shifted to 37 °C. (C) PEDV (PFU=5×10³/ml), peptides, and Vero cells were co-incubated at 37 °C for 1 h then washed prior to assaying. (D) PEDV was treated with various concentrations of peptides H or F at 4 °C or 37 °C for 1 h then used to infect Vero cells (PFU=5×10³/ml) at 37 °C. Peptide concentrations 1, 2, 3, 4, and 5 are 250 μg/ml, 125 μg/ml, 62.5 μg/ml, 31.25 μg/ml, and 15.625 μg/ml, respectively. Anti-PEDV antibody dilutions 1, 2, 3, 4, and 5 are 1:4, 1:8, 1:16, 1:32 and 1:64, respectively. Plaque assays were further performed at 72 h post-infection. Bars show the standard deviation from three independent assays.