Host-cell Reactivation in Mammalian Cells

Summary

The different repair-replication abilities of cells from different species of mammals suggest that mammalian cells may express different levels of host-cell reactivation. This was confirmed using u.v.-irradiated herpes simplex virus assayed in mouse, rat, monkey, and human cells. The survival curves usually had two components, the slopes of both varying among the different cells. The slopes of the first, sensitive components varied considerably (factor of 4), implying that there are different amounts of host-cell reactivation in this component. The slopes of the second, resistant components also varied, implying different extents of host-cell reactivation there also. That the HCR of the first component apparently varied independently of that of the second component among the different host cells suggested that different mechanisms were responsible for the two HCR's. At the virus concentrations used, multiplicity reactivation was not found. The known cellular radiation recovery mechanisms, repair replication and a recovery process occurring during DNA synthesis, were discussed regarding the host-cell reactivation.