Triple gene-deleted oncolytic herpes simplex virus vector double-armed with interleukin 18 and soluble B7-1 constructed by bacterial artificial chromosome-mediated system

Cancer Res. 2005 Dec 1;65(23):10663-8. doi: 10.1158/0008-5472.CAN-05-2534.


Conditionally replicating herpes simplex virus type 1 (HSV-1) vectors are promising therapeutic agents for cancer. Certain antitumor functions may be added to oncolytic activities of recombinant HSV-1 vectors by inserting transgenes into the viral genome. Because conventional homologous recombination techniques had required time-consuming processes to create "armed" oncolytic HSV-1 vectors, we established an innovative construction system using bacterial artificial chromosome and two recombinase systems (Cre/loxP and FLPe/FRT). Using G47Delta, a safe and efficacious oncolytic HSV-1 with triple gene mutations, as the backbone, this system allowed a rapid generation of multiple vectors with desired transgenes inserted in the deleted ICP6 locus. Four oncolytic HSV-1 vectors, expressing murine interleukin 18 (mIL-18), soluble murine B7-1 [B7-1-immunoglobulin (B7-1-Ig)], both, or none, were created simultaneously within 3 months. In vitro, all newly created recombinant vectors exhibited virus yields and cytopathic effects similar to the parental G47Delta. In two immunocompetent mouse tumor models, TRAMP-C2 prostate cancer and Neuro2a neuroblastoma, the vector expressing both mIL-18 and B7-1-Ig showed a significant enhancement of antitumor efficacy via T-cell-mediated immune responses. The results show that "arming" with multiple transgenes can improve the efficacy of oncolytic HSV-1 vectors. The use of our system may facilitate the development and testing of various armed oncolytic HSV-1 vectors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B7-1 Antigen / genetics*
  • Chlorocebus aethiops
  • Chromosomes, Artificial, Bacterial
  • Gene Deletion
  • Genetic Vectors / genetics
  • Herpesvirus 1, Human / genetics*
  • Interleukin-18 / genetics*
  • Male
  • Mice
  • Mice, Inbred A
  • Mice, Inbred C57BL
  • Neuroblastoma / genetics
  • Neuroblastoma / therapy
  • Neuroblastoma / virology
  • Oncolytic Virotherapy / methods*
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / therapy
  • Prostatic Neoplasms / virology
  • Recombinases / genetics
  • Transfection
  • Vero Cells


  • B7-1 Antigen
  • Interleukin-18
  • Recombinases