Figure 1.

Comparison of three candidate viruses (OTS-412, OTS-C1, and OTS-C2) which express different truncated herpes simplex virus (type 1) thymidine kinase (HSV-tk). (A) Western blot of 20 representative plaques (from a total of 120 plaques) obtained after bromodeoxyuridine (BrdU) selection that did not express the full-length HSV-tk (far left lane), and instead consist of at least one of three different virus strains (OTS-412, OTS-C1, or OTS-C2), each expressing a different length of HSV-tk. Full-length gel images were shown in Figure A1. (B) HSV-tk and Fluc transgene cassettes in the vaccinia virus thymidine kinase (VV-tk) region of the three candidate viruses (flank regions not shown). VV-tk deleted OVV (VV^tk-), the shuttle plasmid (pOTS), shadow regions corresponding to ATP-binding domain (ABD) and nucleoside-binding domain (NBD) of the HSV-tk molecule are included for reference. (C) Comparison of viral replication at 0, 24, 48, and 72 h between three virus strains (VV^tk-, OTS-412, OTS-C1, and OTS-C2; at 0.1 PFU/cell) in four different human cancer cell lines, measured by plaque assay. (D) Cytopathic effects in human normal cell line HUVEC-C after 24-h infection with Wyeth vaccinia virus (VACV) or OTS-412 at 10 PFU/cell. Control is no viral infection. Arrows indicate cells showing cytopathic changes. Scale bar: 400 μm. (E) OTS-412 luciferase detected in HUVEC-C and HT-29 cells, after 24-h infection with OTS-412 at 10 PFU/cell.