Figure 5. The PDGF ligand (PDGF-AA) and PDGFRα antibodies do not reduce HCMV infection of epithelial, endothelial cells, and fibroblasts.

(A) ARPE-19, HUVECs, or foreskin fibroblasts (HFF) were pre-treated with PDGF-AA ligand at various concentrations at 4°C for 30 min then HCMV TR (10 IU/cell, 1 IU/cell for fibroblasts) was added to the cells in the presence of PDGF-AA at 4°C for an additional 30 min. The cells were shifted to 37°C for 4 hr then washed to remove the virus inoculum and fresh growth media containing the same concentration of PDGF-AA was added. After an additional 24 hr, the cells were fixed, permeabilized, and stained for HCMV IE-86. Relative entry was characterized by comparing the number of IE-86 positive cells in three separate fields with other dishes of cells not treated with PDGFR-AA. Error bars indicate the standard deviation. B) ARPE-19 cells, C) HUVE cells or D) human foreskin fibroblasts were incubated with various doses of PDGFRα-specific antibodies for 1 hr at 4°C then incubated with HCMV TR (10 IU/cell, 1 PFU/cell for fibroblasts) in the presence of these antibodies for an additional 1 hr at 4°C. The cells were then shifted to 37°C for 4 hr, washed to remove the virus inoculum then incubated at 37°C for 24 hr in the presence of antibodies. The cells were then stained for IE-86. Relative entry refers to the frequency of IE-86 positive cells compared to cells not treated with antibodies and was determined from at least three separate fields. Error bars indicate the standard deviation.