FIG. 3.

Heparin only partially removes gB or competes with attachment of gB to cells. (A) Vero cells seeded in 96-well plates were incubated with 10 nM gB(730t) or 6 nM gC(457t). After 1 h at 4°C, glycoprotein-containing medium was removed and replaced by fresh medium together with various concentrations of heparin. Cells were incubated for 1 h, washed, and fixed and the level of glycoprotein associated with the cell surface was measured by CELISA with polyclonal antibodies R47 and R69 to gC and gB, respectively. (B) gB(730t) or gC(457t) was incubated for 1 h in the presence of various concentrations of heparin. Glycoprotein-plus-heparin mixtures were added to Vero cells seeded in 96-well plates, and incubation continued for another hour. Cells were then washed and fixed, and glycoproteins associated with the cell surface were revealed by CELISA as described in the legend to panel A.