Envelope-targeted retrovirus vectors transduce melanoma xenografts but not spleen or liver.
Many cancer gene therapy applications would benefit from the development of targeted vectors that could deliver genes in vivo. We have previously achieved efficient in vitro targeting of retrovirus vectors to melanoma cells by fusion of a single chain antibody recognizing the high-molecular-weight melanoma-associated antigen (HMWMAA), followed by a blocking peptide and a matrix metalloprotease cleavage site, to the amino terminus of the murine leukemia virus amphotropic strain envelope. Here we report that up to 3% of cells within an HMWMAA-positive tumor xenograft were infected following a single injection of targeted vector into the tumor and up to 10% of tumor cells became infected when they were co-injected with viral producer cells. No infected cells were detected after delivery of targeted vectors to HMWMAA-negative tumor xenografts. Intraperitoneal injection of amphotropic vectors or producer cells resulted in transduction in spleen and liver, which was not detected when targeted vectors or producer cells were used. Our results demonstrate the feasibility of using targeted retroviral vectors for in vivo gene delivery to tumors and highlight the safety benefits of targeted vectors that do not infect other host tissues.
Martín
Francisco
F
Department of Immunology and Molecular Pathology, Windeyer Institute of Medical Science, University College London, 46 Cleveland Street, London W1P 6DB, UK. f.martin-molina@ucl.ac.uk
Chowdhury
Simon
S
Neil
Stuart
S
Phillipps
Neil
N
Collins
Mary K
MK
D000818:Animals; D000912:Antibodies, Neoplasm / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D005822:Genetic Vectors; D008099:Liver / Q000502:physiology; D008545:Melanoma / Q000235:genetics* / Q000628:therapy; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009928:Organ Specificity; D012190:Retroviridae; D013154:Spleen / Q000502:physiology; D014161:Transduction, Genetic; D014183:Transplantation, Heterologous
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm