An effect of cell-culture passage on ultraviolet-enhanced viral reactivation by mammalian cells

The ability of ultraviolet-irradiated African green monkey kidney cells to reactivate UV-damaged herpes simplex virus was tested over a range of 57 passages (24-81). Several types of controls were employed to minimize daily variations. The results indicate that in this system cells demonstrate an increasing efficiency to reactivate UV-damaged virus until approx. passage 60, followed by a decrease in this ability beyond this passage. Chromosome counts at selected passages revealed no significant change in chromosome number as a function of passage. The mechanism(s) or factor(s) causing this effect are unknown.