FIG. 8.

HCMV gB and gH/gL induce cell-cell fusion when expressed in ARPE-19 cells in trans. (A) Cell-cell fusion after ARPE-19 cells expressing gB were mixed with ARPE-19 cells expressing gH and gL (B→H/L). Control assays were performed after mixing ARPE-19 cells expressing either gB or gH and gL alone (B→B and H/L→H/L, respectively). Cell monolayers were fixed and fluorescently stained with propidium iodide to label cell nuclei. (B) Quantification of cell-cell fusion mediated by gB and gH/gL in trans under the conditions described in the legend to Fig. 1. Values represent the averages derived from three separate images, and the error bars indicate the standard deviations. Asterisks indicate that no fusion was observed.