New Advanced Technology for Muscular Dystrophy

Authors: Johnny Huard; CHILDREN'S HOSPITAL OF PITTSBURGH PA

Abstract:

Researchers continue to investigate whether gene transfer to skeletal muscle can enable both the production of proteins that might be therapeutic for muscle disorders and the systemic delivery of non-muscle proteins. Although the engineering of new mutant vectors has reduced the problems associated with viral cytotoxicity and immune rejection after gene transfer, the inability of most viral vectors to efficiently transduce mature muscle fibers continues to impede gene transfer to skeletal muscle. Results from our laboratory and others have shown that adenovirus (AV), retrovirus (RSV), and herpes simplex virus (HSV) vectors all can transduce neonatal mouse muscle efficiently; however, the muscle becomes largely resistant to viral transduction within a few days after birth. We have identified the primary barriers of viral gene transfer to mature skeletal muscle and have investigated methods by which to overcome these barriers. Among such approaches, the ex vivo technique constitutes the most efficient method for delivery of viral vectors (AV, RSV, and HSV) to mature skeletal muscle. In this project, we will investigate ex vivo gene transfer to the dystrophic skeletal muscle of mature mdx mice (which model Duchenne muscular dystrophy) by using isogenic muscle-derived cells (satellite cells or muscle-derived stem cells [MDSCs]) and retroviral vectors encoding for a functional human mini-dystrophin gene. We first will compare these 2 populations of muscle-derived cells-satellite cells and MDSCs-to identify which cell type serves as the more efficient gene delivery vehicle in mdx mice (Technical Objective 1). We then will evaluate whether restricting the transgene expression specifically to skeletal muscle fibers after ex vivo gene transfer influences the efficiency and long-term persistence of dystrophin expression in mdx muscles (Technical Objective 2).

Limitations:

APPROVED FOR PUBLIC RELEASE