Duchennes Muscular Dystrophy (DMD) is an X-linked recessive disorder caused by a deficiency of the protein dystrophin (Dys). Absence of this important cytoskeletal protein leads to progressive muscle wasting and death. One approach for treating this lethal disease is replacement therapy through myoblast transplantation or gene therapy. This project will attempt to develop the delivery vehicles necessary to efficiently transfer Dys minigenes to skeletal muscle in animal models. Gene therapy for DMD is associated with several experimental challenges. The gene delivery vehicle must 1) accommodate athe normal minigene, which in the cause of a full length human Dys cDNA is 14 kb, and 2) efficiently, stable, and safely target a large number of skeletal muscle fibers in vivo. We propose to develop recombinant adenoviruses as vehicles for DMD gene therapy. Preliminary studies indicate that recombinant adenoviruses of the Ad5 serotype are tropic for skeletal muscle myotubes under the right experimental conditions in vivo. Current vectors are limited for DMD gene therapy because 1) they cannot accommodate anything longer than 8 kb, and 2) they are not truly replication defective and, as a result, elicit cellular immune responses in vivo which lead to loss of transgene expression through destruction of the target cell and inflammation. Our studies will utilize the mouse as an experimental model for developing and evaluating adenoviral vectors for gene therapy because of the simplicity of studying immunology and the existence of murine models of DMD. Experiments in this proposal will utilize reporter genes and non-DMD mice. Our initial focus will be to define the immunological responses of the host to the virus and virus and virus infected cells. Experience in other systems should predict that class I restricted cytotoxic T lymphocytes to viral antigens expressed in transduced cells are important immune effectors while class II restricted T helper and B cell responses to input viral proteins, which generate neutralizing antibody, result in difficulties in achieving gene transfer on repeat administration of virus. A significant effort will be made to further cripple the virus by deleting essential genes to minimize viral protein expression and the resulting immune responses and to provide more space within the vector to accommodate Dys minigenes.

Project Start
1998-07-01
Project End
1999-06-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
4
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Bridges, Charles R; Burkman, James M; Malekan, Ramin et al. (2002) Global cardiac-specific transgene expression using cardiopulmonary bypass with cardiac isolation. Ann Thorac Surg 73:1939-46
Cordier, L; Gao, G P; Hack, A A et al. (2001) Muscle-specific promoters may be necessary for adeno-associated virus-mediated gene transfer in the treatment of muscular dystrophies. Hum Gene Ther 12:205-15
Croyle, M A; Chirmule, N; Zhang, Y et al. (2001) ""Stealth"" adenoviruses blunt cell-mediated and humoral immune responses against the virus and allow for significant gene expression upon readministration in the lung. J Virol 75:4792-801
Croyle, M A; Cheng, X; Sandhu, A et al. (2001) Development of novel formulations that enhance adenoviral-mediated gene expression in the lung in vitro and in vivo. Mol Ther 4:22-8
Zoltick, P W; Chirmule, N; Schnell, M A et al. (2001) Biology of E1-deleted adenovirus vectors in nonhuman primate muscle. J Virol 75:5222-9
Zhang, Y; Chirmule, N; Gao, G P et al. (2001) Acute cytokine response to systemic adenoviral vectors in mice is mediated by dendritic cells and macrophages. Mol Ther 3:697-707
Louboutin, J P; Rouger, K; Tinsley, J M et al. (2001) iNOS expression in dystrophinopathies can be reduced by somatic gene transfer of dystrophin or utrophin. Mol Med 7:355-64
Gao, G; Qu, G; Burnham, M S et al. (2000) Purification of recombinant adeno-associated virus vectors by column chromatography and its performance in vivo. Hum Gene Ther 11:2079-91
Chirmule, N; Xiao, W; Truneh, A et al. (2000) Humoral immunity to adeno-associated virus type 2 vectors following administration to murine and nonhuman primate muscle. J Virol 74:2420-5
Cordier, L; Hack, A A; Scott, M O et al. (2000) Rescue of skeletal muscles of gamma-sarcoglycan-deficient mice with adeno-associated virus-mediated gene transfer. Mol Ther 1:119-29

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