ANALYSIS OF THE RELATIONSHIP BETWEEN CELLULAR THYMIDINE KINASE-ACTIVITY AND VIRULENCE OF THYMIDINE KINASE-NEGATIVE HERPES-SIMPLEX VIRUS TYPE-1 AND TYPE-2
T. Suzutani et al., ANALYSIS OF THE RELATIONSHIP BETWEEN CELLULAR THYMIDINE KINASE-ACTIVITY AND VIRULENCE OF THYMIDINE KINASE-NEGATIVE HERPES-SIMPLEX VIRUS TYPE-1 AND TYPE-2, Microbiology and immunology, 39(10), 1995, pp. 787-794
The virulence of thymidine kinase-negative herpes simplex virus type 1
(HSV-1; VRTK(-) strain) and type 2 (HSV-2; UWTK- strain) was studied
in comparison with that of their parental strains (VR-3 and UW-268, re
spectively) in an encephalitis model of adult (4-week-old) and newborn
(3-day-old) mice. Viral thymidine kinase (TK) activity was essential
for the maximum expression of virulence of HSV-1, because the 50% leth
al dose (LD(50)) of VRTK(-) was 60 times higher than that of VR-3 in t
he brains of newborn mice expressing high levels of cellular TK activi
ty. However, the UWTK- strain showed the same virulence as the parenta
l strain in newborn mice, despite the lack virulence in adults, sugges
ting that replication of the UWTK- strain was completely supported by
cellular TK activity. This difference in the role of viral and-cellula
r TKs for virus growth between HSV-1 and HSV-2 was confirmed with the
one-step growth of virus strains in L-M and L-M(TK-) cells.