Thérapie génique de la dystrophie musculaire de duchenne : utilisation de transgènes de la dystrophine chez le modèle canin

Authors: Pichavant, Christophe
Advisor: Tremblay, Jacques-P.
Abstract: Duchenne muscular dystrophy is a genetic disease affecting 1 out of every 3500 boys. This X-linked pathology is characterised by the absence of dystrophin in myofibers. This lack of dystrophin leads to a progressive muscular degeneration. DMD patients die between 17 and 30 years of age. There are currently no curative treatments for this disease. An approach to restore dystrophin in DMD patients is to introduce a transgene coding for this protein into their muscles. This can be done by gene therapy, particularly by ex vivo gene therapy or by electroporation. Even if these 2 techniques have shown good results in mouse models, they have not been used in the dystrophic dog. Two different isoforms of the dystrophin were used in our experiments: the full length dog dystrophin and a shorter version, the dog micro-dystrophin, introduced in a lentivirus backbone. Myoblasts were transduced with this lentivirus and transplanted successfully in immunodeficient mouse. However, the autotransplantation of genetically modified dog myoblasts led to a specific rejection of the grafted cells. A non viral gene therapy (electroporation, i.e., injection of a plasmid followed by a sequence of electric pulses) was used to introduce these two different isoforms of dystrophin in mouse and (normal and dystrophic) dog muscles. The two transgenes were electroporated with success in these muscles. However, a specific immune response was found in some myofibers expressing the transgene in the normal dog (using micro-dystrophin) and in the dystrophic dog (using full length dystrophin). Although the results obtained with the ex vivo gene therapy and with the electroporation were relatively effective in the mouse model, those obtained with the dog model were much lower. Thus, lots of improvements remain to be made in order to consider these two techniques as potential approaches to restore dystrophin in a large animal model and eventually in DMD patients.
Document Type: Thèse de doctorat
Issue Date: 2010
Open Access Date: 16 April 2018
Permalink: http://hdl.handle.net/20.500.11794/21607
Grantor: Université Laval
Collection:Thèses et mémoires

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