Persistence in muscle of an adenoviral vector that lacks all viral genes

Abstract

Genetic correction of inherited muscle diseases, such as Duchenne muscular dystrophy, will require long term expression of the recombinant protein following gene transfer. We have shown previously that a new adenoviral vector that lacks all viral genes expressed both full-length dystrophin and ␤-galactosidase in mdx (dystrophin-deficient) mouse muscle. We observed a significant histologic improvement of vector-transduced mdx muscle before the eventual loss of vector-encoded transgene expression. In this study, we investigated whether an immunological response against vector-encoded ␤-galactosidase contributed to the loss of vector expression and affected vector persistence in muscle. Intramuscular vector injection in control normal mice resulted in an early and complete loss of ␤-galactosidase expression accompanied by predominantly CD4 ؉ and CD8؉ lymphocytic infiltration and a significant loss of vector DNA. In contrast, intramuscular vector injection in lacZ transgenic mice resulted in persistent expression of ␤-galactosidase for at least 84 days with no evidence of inf lammation or significant loss of vector DNA. Our studies demonstrate that, in the absence of an immune response induced by ␤-galactosidase expression, an adenoviral vector lacking all viral genes is stably maintained in muscle.

Efficient repetitive gene delivery to skeletal muscle using recombinant adenovirus vector containing the Coxsackievirus and adenovirus receptor cDNA

“…We suggest that co-expression of CAR and a therapeutic gene should be useful for efficient rAd-mediated gene transduction to skeletal muscle and that a combination of this method and previously reported strategies [7][8][9][10] would result in beneficial clinical applications in the future.…”

“…To avoid immune reactions to both first-generation rAds 6 and expressed proteins, namely ␤-galactosidase from E. coli, 9 GFP from jellyfish, and human CAR, we used nude mice in this study. If immune reactions to them could be suppressed, our strategy would be applied to gene transduction to immunocompetent hosts.…”

“…At present, some strategies that protect vectors from the host immune system have been proposed, for example, FK506 immunosuppression agent, 7 CTLA4Ig, 8 a gutted adenovirus vector which produces less protein from adenovirus. [9][10][11] Adding our method to these strategies would provide muscles of immunocompetent animals with efficient therapeutic gene expression for a long period.…”

“…Some researchers have reported that immune reaction to rAd has been suppressed by FK506 immunosuppression agent, 7 CTLA4Ig, 8 and a gutted adenovirus vector. [9][10][11] Thus, repetitive transduction to skeletal muscle could seem valid for consecutive expression of a therapeutic gene. The latter is caused by a maturation-dependent loss of the myofiber's susceptibility to rAd uptake which is due to structural and biochemical changes during muscle maturation.…”

Gutless adenovirus: last-generation adenovirus for gene therapy

“…68 Gutless vectors have been shown to express non-immunogenic transgenes during the whole life of the mouse, while expression driven by first-generation adenovirus lasted at most for 3 months. [80][81][82] Therapeutic genes carried by gutless vectors have been administered to the liver of mouse models for different diseases, such as hemophilia A and B, 83,84 obesity, 66 familial hypercholesterolemia, 81,85-87 ornithine transcarbamylase deficiency, 88 diabetes 89 and chronic viral hepatitis. 90,91 Therapeutic levels of most proteins have been documented for a long-term duration.…”