FIG. 4.

DAF-specific antibodies and soluble DAF block entry of HTNV. (A) Lysates of Vero C1008 cells were analyzed by Western blotting with polyclonal anti-DAF antibody H319. (B) Surface expression of DAF was assessed by flow cytometry. Vero C1008 cells were stained with anti-DAF antibody and FITC-conjugated secondary antibody and analyzed by flow cytometry. The open histogram represents the secondary-antibody control, and the shaded histogram represents cells stained with DAF-specific primary and appropriate fluorescently labeled secondary antibody. (C) Cells were incubated with increasing concentrations of DAF-specific antibody (anti-DAF H319) prior to infection. At 48 h postinfection, infected cells were quantified by the immunofluorescence analysis of N-protein expression. The data are representative of three independent experiments. Error bars represent standard deviations. (D) HTNV particles were preincubated with increasing concentrations of rhDAF. Confluent monolayers of Vero C1008 cells were infected with untreated particles or particles that had been pretreated with rhDAF. At 48 h postinfection, cells were lysed and analyzed for expression of N protein and tubulin. Similar results were obtained in three independent experiments; results of a representative one are shown here. (E) Vero C1008 cells were infected with HTNV particles pretreated with rhDAF. At 48 h postinfection, cells were stained for N protein, and infected cells were quantified by counting N-protein-expressing cells.