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.

Induction capacity and influence of dThdMP on thymidine kinase activity of type 1 and 2 strains of herpes simplex virus

“…These cell cultures are suitable for these experiments, because their own thymidine-and desoxyeytidine kinase activity is low and the cells were used after 2 cycles of herpes infection and after shut off of host protein synthesis (2,3,7). During the course of the experiments we obtained completely comparable data of enzyme activity in both types of cells.…”

Влияние На Гама Лъчите Върху Тимидин Киназната Активност На Щамоbе На Вируса На Псевдобеса

“…Неговата изходна стойноет на S -11% след облъчване с 4 KGy пада на 8%. Електрофоретичният профил на Bam Hl фрагментяте на ДНК, изолирана от облъчените с 4 KGy щамове, е еднакъв с профила на фрагментяте на необ лъчените щамове, показани на фиг 3…”