Engineering and Preclinical Evaluation of Western Reserve Oncolytic Vaccinia Virus Expressing A167Y Mutant Herpes Simplex Virus Thymidine Kinase.

Viral replication of deleted () vaccinia virus (VV) is attenuated in resting normal cells, enabling cancer selectivity, however, replication potency of VV appears to be diminished in cancer cells. Previously, we found that wild-type herpes simplex virus (HSV () disappeared in most of the recombinant VV after multiple screenings, and only a few recombinant VV containing naturally mutated remained stable. In this study, VV of western reserve (WR) VV was replaced by A167Y mutated (), to alter nucleoside selectivity from broad spectrum to purine exclusive selectivity.