Therapeutic gene transfer to dystrophic diaphragm by an adenoviral vector deleted of all viral genes.
Duchenne muscular dystrophy is caused by defects in the dystrophin gene, and the mdx mouse is the most frequently employed genetic model of this disease. It is well known that different muscle groups do not respond in the same way to dystrophin deficiency. In particular, the mdx mouse diaphragm exhibits severe morphological and functional changes not found in other mdx muscles. Use of early generation adenoviral vectors to deliver genes to the diaphragm in immunocompetent mdx mice has been associated with substantial functional toxicity and a rapid loss of transgene expression. Here we determined the response to dystrophin gene replacement in the mdx diaphragm using a "gutted" adenoviral vector that contains the coding sequence of two full-length dystrophin genes and is deleted of most viral DNA sequences. At 1 wk postdelivery of the vector, 23.6 +/- 4% of total fibers in the injected diaphragm bundle expressed dystrophin at the sarcolemma, which remained stable over the study duration of 30 days without the need for continuous immunosuppression. Treated diaphragms showed a significantly improved resistance to the abnormal force deficits induced by high-stress muscle contractions, the latter being a functional hallmark of dystrophin-deficient muscle. This functional amelioration was achieved despite the presence of mildly increased inflammation (CD4+ and CD8+ lymphocytes) within the vector-treated diaphragms. To our knowledge, this is the first demonstration that a viral vector can achieve reversal of functional abnormalities in the dystrophic diaphragm via therapeutic dystrophin gene transfer without the need for sustained immunosuppressive therapy.
Matecki
Stefan
S
Respiratory Division, Rm. L411, Royal Victoria Hospital, 687 Pine Ave. W., Montréal, Québec, Canada H3A 1A1.
Dudley
Roy W R
RW
Divangahi
Maziar
M
Gilbert
Renald
R
Nalbantoglu
Josephine
J
Karpati
George
G
Petrof
Basil J
BJ
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003964:Diaphragm / Q000276:immunology / Q000502:physiology*; D016189:Dystrophin / Q000235:genetics*; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D009137:Muscular Dystrophy, Animal / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000628:therapy
D016189:Dystrophin