Duchenne muscular dystrophy (DMD) is common and fatal X-linked genetic disorder. The overall objective of this thesis was to carry out a prospective study for dystrophin gene therapy in dystrophic muscles, using the X-linked muscular dystrophy (mdx) mouse model. Recombinant adenovirus (AdV) is presently the vehicle of choice for gene therapy for a number of diseases including DMD. However AdV possess two major limitations when utilized as vectors in skeletal muscles: (i) the maturation-dependency of AdV-infectivity in skeletal muscles, (ii) the host immune response against adenoviral proteins as well as the transgene product. Thus, the work presented in this thesis addresses these two major limiting factors. By modifying either the host or the vectors, we have attempted to optimize AdV-mediated therapeutic gene transfer in dystrophic muscle. Our strategy has consisted firstly to evaluate the regenerative response of dystrophic muscle with advanced disease after experimentally-induced regeneration, in an attempt to recapitulate the myogenic program. We report that mdx mice with severe dystrophic pathology can still show a substantial level of muscle repair with attendant generation of immature myofibers. Secondly, by taking advantage of this level of regeneration and the concomitant generation of immature myofibers, we have upregulated expression of the coxsackie adenovirus receptor (CAR) present in mdx muscles. We have delivered AdV containing a dystrophin gene (AdV-Dys) at a period corresponding to this peak level of CAR expression and we have reported a significant increase of the number of dystrophin expressing myofibers with a net trend toward muscle function amelioration. / The work of this thesis also reports that the combined blockade of calcineurin and CD28 signaling, two key and distinct elements needed for an effective immune response, effectively blunted the immune-mediated destruction of dystrophin expressing myofibers expressed after AdV-Dys delivery. As an alternative to host modification (regeneration and immunosuppression) that can be associated with potential toxic effects, we have explored a strategy where by the recombinant AdV vector contains a less immunogenic transgene utrophin. We report that overexpression of utrophin and dystrophin by AdV-mediated gene transfer in adult immunocompetent mdx mice produces differential effects on muscle cell function in adult immunocompetent (mdx) mice. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36945 |
| Date | January 2000 |
| Creators | Guibinga, Ghiabe H. |
| Contributors | Petrof, B. J. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Division of Experimental Medicine.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001802368, proquestno: NQ70036, Theses scanned by UMI/ProQuest. |
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