Fig. 4.

Viral entry activities of the HSV-1 and HSV-2 gD mutants in CHO-HVEM and CHO-nectin-1 cells. HSV-1 and HSV-2 gD-negative mutant viruses were passed through cells expressing each of the wild-type and mutant forms of gD so that the viral envelopes would incorporate the various forms of gD (complementation). Mutants Q27P and Δ7–32 have been described (22). The complemented viruses, which can express β-gal from inserts in the viral genome, were used to inoculate CHO-HVEM and CHO-nectin-1 cells in 96-well dishes. After 24 h, the cells were lysed, and β-gal activity (OD₄₀₅ for detection of the reaction product) was quantified as a measure of viral entry. The results are normalized to the viral entry activity observed with wild-type gD, set at 100%. Percent of wild-type gD activity = [(absorbance for mutant gD–absorbance in the absence of gD)/(absorbance for wild-type gD–absorbance in the absence of gD)] × 100. The results shown are the means and standard deviations for at least three independent experiments, each done in triplicate.