Duchenne Muscular Dystrophy (DMD) in both humans and dogs is a fatal, X-linked, recessive muscle disease caused by lack of dystrophin due to deletions or mutations in the dystrophin gene. Adeno-associated virus (AAV)-mediated delivery of micro-dystrophin to skeletal muscle has been successful in mice;however, recent studies indicate that the efficacy of AAV-mediated therapies might be limited by an immune response to viral capsid proteins in humans. By direct intramuscular injection of AAV vectors in wild type and cxmd (canine X- linked muscular dystrophy) dogs, we demonstrated robust cellular immune responses to AAV capsid proteins, suggesting the likelihood of cellular immunity to AAV vectors in humans. We further demonstrated that the immune response generated following intramuscular injection of AAV vectors could be averted by a brief course of intense immunosuppression. The broad, long-term objective of this project is to develop AAV- mediated gene therapy strategies in cxmd dogs that can be applied to human patients with DMD. In this revision application, we propose to test novel AAV vectors that appear to be much less immunogenic than current vectors. These vectors have been developed by Drs. Miller and Halbert at the FHCRC and are based on their finding that current AAV vectors can transfer and express AAV capsid genes, and that transfer can be avoided by modification of the vector production system. Here we propose to test the hypothesis that these novel vectors will significantly reduce immune responses in normal and cxmd dogs leading to a reduced need for immunosuppression. These studies will provide necessary information for future human trials of AAV- mediated gene therapy in humans with Duchenne muscular dystrophy.

Public Health Relevance

The significance of this revision application is that the methodologies developed in the canine X-linked muscular dystrophy (cxmd) model can be used to treat human patients with Duchenne muscular dystrophy (DMD). Reducing the immunogenicity of AAV vectors and developing better and less toxic immunosuppression regimens will increase the likelihood of achieving the goal of effective gene therapy for human DMD.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
3R01AR056949-02S1
Application #
8042105
Study Section
Skeletal Muscle and Exercise Physiology Study Section (SMEP)
Program Officer
Nuckolls, Glen H
Project Start
2008-12-01
Project End
2012-06-30
Budget Start
2010-09-04
Budget End
2011-06-30
Support Year
2
Fiscal Year
2010
Total Cost
$107,802
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
078200995
City
Seattle
State
WA
Country
United States
Zip Code
98109
Wang, Z; Halbert, C L; Lee, D et al. (2014) Elimination of contaminating cap genes in AAV vector virions reduces immune responses and improves transgene expression in a canine gene therapy model. Gene Ther 21:363-70
Kerwin, William S; Naumova, Anna; Storb, Rainer et al. (2013) Mapping contrast agent uptake and retention in MRI studies of myocardial perfusion: case control study of dogs with Duchenne muscular dystrophy. Int J Cardiovasc Imaging 29:819-26
Wang, Zejing; Storb, Rainer; Tapscott, Stephen J et al. (2012) Analyzing cellular immunity to AAV in a canine model using ELISPOT assay. Methods Mol Biol 792:65-74
Wang, Zejing; Storb, Rainer; Halbert, Christine L et al. (2012) Successful regional delivery and long-term expression of a dystrophin gene in canine muscular dystrophy: a preclinical model for human therapies. Mol Ther 20:1501-7
Wang, Zejing; Tapscott, Stephen J; Chamberlain, Jeffrey S et al. (2011) Immunity and AAV-Mediated Gene Therapy for Muscular Dystrophies in Large Animal Models and Human Trials. Front Microbiol 2:201
Arnett, Andrea L H; Garikipati, Dilip; Wang, Zejing et al. (2011) Immune Responses to rAAV6: The Influence of Canine Parvovirus Vaccination and Neonatal Administration of Viral Vector. Front Microbiol 2:220
Wang, Zejing; Tapscott, Stephen J; Storb, Rainer (2011) Local gene delivery and methods to control immune responses in muscles of normal and dystrophic dogs. Methods Mol Biol 709:265-75
Wang, Zejing; Storb, Rainer; Lee, Donghoon et al. (2010) Immune responses to AAV in canine muscle monitored by cellular assays and noninvasive imaging. Mol Ther 18:617-24
Halbert, Christine L; Madtes, David K; Vaughan, Andrew E et al. (2010) Expression of human alpha1-antitrypsin in mice and dogs following AAV6 vector-mediated gene transfer to the lungs. Mol Ther 18:1165-72