title: Influence of double infections on the induction of thymidine kinase by UV-irradiated herpes simplex virus types 1 and 2 and pseudorabies virus.
abstract: Simultaneous infection of primary rabbit kidney cells with HSV type 1 TK+ and a TK- strain results in a mutual influence of both viruses on the induction of thymidine kinase (TK). TK+ virus has an enhancing and TK- virus a depressing effect on TK induction by a superinfecting TK+ virus. The enzyme induction depends on the ratio of multiplicities of both viruses. The mutual influence on TK induction depends further on the time of addition of the superinfecting virus: the effect of the second virus can still be observed when given 6 hours after primary infection. Identical phenomena can be observed using combinations with HSV type 2 or Pseudorabies viruses. The ability of HSV to induce TK is progressively inactivated with increasing the time of UV-irradiation. The depressing effect of a TK- strain and the stimulating effect of a TK+ strain on superinfecting TK+ strains is UV-sensitive: after 6 minutes of UV-irradiation neither inhibition nor stimulation of TK induction by a superinfecting TK+ strain can be observed. Infection by long-term (20 minutes) UV-irradiated TK+ strains results in a depression of TK induction by a superinfecting TK+ virus. Long-term irradiation of the TK- virus does not show this effect. Cytosine-arabinoside has no effect on the mutual influence of TK induction by TK+ and TK-strains; the phenomenon of mutual depression therefore has to be considered an early process.
mesh_terms: D002474:Cell-Free System; D046508:Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D003561:Cytarabine / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects / Q000528:radiation effects; D006564:Herpesviridae / Q000378:metabolism*; D011558:Herpesvirus 1, Suid / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D009154:Mutation; D011830:Radiation Effects; D018139:Simplexvirus / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D013937:Thymidine Kinase / Q000096:biosynthesis* / Q000378:metabolism; D014466:Ultraviolet Rays; D014762:Viral Interference; D014779:Virus Replication / Q000528:radiation effects
chemical_list: D003561:Cytarabine; D003513:Cycloheximide; D013937:Thymidine Kinase