Fig. 2

PTD-poMx1 did not inhibit CSFV entry. Virus binding to the surface of ST (a) and 3D4/21 (b) cells with or without PTD-poMx1 was determined using flow cytometry analysis. ST or 3D4/21 cells treated with or without 80 μg/ml PTD-poMx1 were inoculated with CSFV at a MOI of 5 for 1 h on ice. The infected cell suspensions were prepared with PBS containing 0.02 % EDTA, and incubated with the anti-E2 monoclonal antibody (WH303) for 1 h at 37 °C. Cells were washed three times with PBS and treated with FITC-labeled goat anti-mouse IgG (1:200) at 37 °C for 30 min. Fluorescent signals on the cell surface were detected and the percentage of positive cells was counted in a sample of 3 × 10⁴ cells. Untreated cells were used as a negative control. Virus uptake in the ST (c) or 3D4/21 (d) cell line with or without PTD-poMx1 was then determined using qRT-PCR. Cells were preincubated with 80 μg/ml PTD-poMx1 for 6 h and incubated with CSFV on ice for 1 h. Then, cells were washed three times with PBS and cultured for 2 h at 37 °C. Internalized viruses were quantified using qRT-PCR