Effects of UV radiation on plaque formation of Herpes Simplex Type 1 on C3H/10T/sub 1/2/ monolayers

HSV-1 plaque-forming ability and plaque sizes were assayed on C3H/10T/sub 1/2/ monolayers as a function of the following variables: (1) pretreatment dose with UV light at different times before inoculation; (2) pretreatment dose with cycloheximide 24 hours before inoculation; and (3) population density of monolayers at time of inoculation. Irradiated virus exhibited smaller plaques than in controls (small plaque effect, SPE). The capacity of the cells was found to increase substantially with pretreatment with UV light or cycloheximide (capacity enhancement effect, CE); these agents also produced larger plaques than on controls (the large plaque effect, LPE). No significant UV light-enhanced reactivation (ER) was observed; thus, UV light-induced ER and LPE were not correlated in this system. Pretreatment with cycloheximide, however, seemed to produce a moderate level of ER