In vivo retrovirus-mediated gene transfer to the liver of dogs results in transient expression and induction of a cytotoxic immune response.
Gene transfer in regenerating dog liver using high-titer recombinant retroviral vectors carrying the E. coli beta-galactosidase gene was studied. Supernatants containing amphotropic or gibbon ape pseudotyped recombinant retroviruses were infused into a peripheral vein in beagle dogs after partial hepatectomy. The kinetics of liver regeneration were determined in the animals and daily infusions were carried out for 4 or 5 days during the regeneration period. Up to 2.8% of hepatocytes were beta-galactosidase positive at the end of the procedure. However, the number of positive cells declined rapidly and few positive hepatocytes were detected after 3 weeks. PCR demonstrated the disappearance of the provirus. Histologically, inflammatory lesions were observed in the transduced livers. Finally, we demonstrated the presence of a cytotoxic T lymphocyte immune response directed against beta-galactosidase-expressing cells, which could explain the disappearance of the transgene. This work suggests that the efficiency of in vivo gene delivery using high-titer retroviral vectors directly infused into the circulation may be hampered by a cytotoxic immune response against the infected cells.
Izembart
A
A
Laboratoire de Thérapie Génique, CHU Hôtel-Dieu, Nantes, France.
Aguado
E
E
Gauthier
O
O
Aubert
D
D
Moullier
P
P
Ferry
N
N
D000818:Animals; D001483:Base Sequence; D003602:Cytotoxicity, Immunologic / Q000235:genetics*; D017931:DNA Primers; D004285:Dogs; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D018014:Gene Transfer Techniques; D008099:Liver / Q000201:enzymology*; D008115:Liver Regeneration / Q000235:genetics; D012190:Retroviridae / Q000235:genetics*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014161:Transduction, Genetic; D001616:beta-Galactosidase / Q000235:genetics
D017931:DNA Primers; D001616:beta-Galactosidase