Triple gene-deleted oncolytic herpes simplex virus vector double-armed with interleukin 18 and soluble B7-1 constructed by bacterial artificial chromosome-mediated system.
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.
Fukuhara
Hiroshi
H
Molecular Neurosurgery Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.
Ino
Yasushi
Y
Kuroda
Toshihiko
T
Martuza
Robert L
RL
Todo
Tomoki
T
D000818:Animals; D018122:B7-1 Antigen / Q000235:genetics*; D002522:Chlorocebus aethiops; D022202:Chromosomes, Artificial, Bacterial; D017353:Gene Deletion; D005822:Genetic Vectors / Q000235:genetics; D018259:Herpesvirus 1, Human / Q000235:genetics*; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D009447:Neuroblastoma / Q000235:genetics / Q000628:therapy / Q000821:virology; D050130:Oncolytic Virotherapy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000235:genetics / Q000628:therapy / Q000821:virology; D045522:Recombinases / Q000235:genetics; D014162:Transfection; D014709:Vero Cells
D018122:B7-1 Antigen; D020382:Interleukin-18; D045522:Recombinases