FIG 8.

Cell-cell fusion mediated by gH and gB mutants. One set of CHO-K1 cells (effector cells) was transfected with plasmids encoding a version of gB (WT, gB3A, SaHV-1 gB, or empty vector), a version of gH (WT, gH-S830N, gH-H789Y, or empty vector), gD, gL, and T7 polymerase. gB and gH versions are indicated below each graph. A second set of CHO-K1 cells (target cells) was transfected with plasmids carrying the luciferase gene under the control of the T7 promoter and nectin-1 receptor. Target and effector cells were cocultured for 6 h and luciferase activity was measured as an indication of cell-cell fusion. Cell-surface expression of gH was determined by CELISA using a duplicate set of effector cells and anti-gH MAb 53S. (A) Mutant gH surface expression when coexpressed with WT gH, gL, and gD. Data are expressed as a percentage of WT gH expression and background signals from cells transfected with vector alone are subtracted. (B) Fusion mediated by gB or gH mutants coexpressed with WT gH or WT gB. Data are expressed as a percentage of fusion in the presence of both WT gH and WT gB. (C) Fusion mediated by gB3A coexpressed with WT gH or gH-S830N. Data are expressed as a percentage of gB3A fusion in the presence of WT gH. (D) Fusion mediated by SaHV-1 gB coexpressed with WT gH or gH-H789Y. Data are expressed as a percentage of SaHV-1 gB fusion in the presence of WT gH. For all graphs, background fusion signals detected after transfection with vector instead of glycoproteins were subtracted from the values.