Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A major impediment to successful implementation of gene therapy for treatment of muscular dystrophy is the restricted infectivity of mature muscle fibers with viral vectors. This phenomenon has been observed with adenovirus vectors and more recently with herpes simplex virus type 1 (HSV-1)-based vectors. Here we report findings of morphological studies designed to experimentally determine the mechanism underlying the rapid reduction in vector-mediated gene delivery concomitant with the maturation of muscle fibers. Using immunohistochemistry and confocal microscopy, we have colocalized HSV-1 and collagen IV, a major component of the basal lamina, in HSV-1-injected muscles and determined that the virus penetrates and expresses a transgene (lacZ) in muscle fibers of newborn animals but cannot efficiently penetrate adult myofibers. This was observed in normal as well as in immunocompromised animals, suggesting that the lack of adult myofiber transduction is not a result of an immune response and clearance of the viral vector. Since heparan sulfate proteoglycan, the initial attachment receptor for HSV-1, was shown to be preserved during the maturation of the myofibers by immunofluorescence assay and HSV-1 was able to infect isolated, viable myofibers in vitro, we suggest that the low-level HSV-1 transduction of mature myofibers is not a consequence of the loss of viral attachment sites on the surfaces of mature muscle fibers. Rather, our results indicate that the mature basal lamina acts as a physical barrier to HSV-1 infection of adult myofibers. This conclusion was further supported by the finding that HSV-1 displayed an intermediate level of transduction in mature dy/dy muscle which is defective for normal basal lamina formation. Together, these experiments suggest that efficient HSV vector transduction in mature skeletal muscle requires methods to permeabilize the basal lamina.
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PMID:The basal lamina is a physical barrier to herpes simplex virus-mediated gene delivery to mature muscle fibers. 889 37

Herpes simplex virus type 1 (HSV-1) amplicon vectors were evaluated for feasibility in gene therapy of Duchenne's muscular dystrophy (DMD). An amplicon vector expressing enhanced green fluorescent protein (eGFP) was examined for transduction efficiency and cytotoxicity in cultured muscle cells, and for transduction efficiency, duration of transgene expression, and immunogenicity in tibialis anterior (TA) muscles of neonatal mice. Transduction efficiencies in murine and human myoblasts were 60-90 and 50-60%, respectively, when myoblasts were transduced at multiplicities of infection (MOIs) of 1-5. Similar transduction efficiencies were observed in myotubes of both species. No cytotoxic effects were noticed at an MOI of 10, the highest MOI tested. An amplicon vector, HyMD, containing the full-length mouse dystrophin cDNA and its muscle creatine kinase (MCK) promoter-enhancer, with a total size of 26 kb, was constructed and used to transduce mdx mouse myotubes. The expression of dystrophin in these cells was demonstrated by immunocytochemistry. After injecting 4-6 x 10(5) transduction units (TU) of HSVGN amplicon vectors, 10-50% of myofibers in the injected TA muscles expressed GFP. Although transgene expression was attenuated over time, significant improvement in long-term transgene expression and persistence of vector DNA was achieved, when compared with the first generation of recombinant HSV-1 vectors. Immunohistochemistry showed a modest CD4(+) lymphocyte infiltration in the vicinity of the injection. A gradually developed CD8(+) lymphocyte infiltration was also seen, most likely related to the antigenicity of the transgene product, GFP. We conclude that the HSV-1 amplicon vector is a promising vehicle for gene delivery in DMD. However, new strategies need to be evaluated to increase the stability of transgene expression.
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PMID:Herpes simplex virus type 1 amplicon vector-mediated gene transfer to muscle. 1181 82

One of the obstacles to efficient vector-mediated gene therapy for Duchenne's muscular dystrophy (DMD) is its limited transduction efficiency. The VP22 tegument protein of herpes simplex virus type 1 (HSV-1) is able to cross biological membranes and translocate the VP22 fusion protein from transfected primary cells to surrounding cells and improve the outcome of gene transfer. To improve the efficiency of vector-mediated gene therapy and to investigate the utility of the intercellular trafficking properties of VP22-linked protein for the treatment for DMD, the recombinant adenoviruses Ad-VP22, Ad-MICDYS, and Ad-VP22-MICDYS were constructed and the VP22-mediated shuttle effect was evaluated both in vitro and in vivo. About 92 +/- 3.6% of cells were microdystrophin positive 48 hr postinfection with Ad-VP22-MICDYS. The number of centralized nuclei in Ad-VP22-MICDYS-transduced tibialis anterior (TA) muscle was significantly reduced, from 78 +/- 5.2 to 20 +/- 2.5%, by 2 weeks postinjection. By 2 months postinjection, the average number of microdystrophin-positive fibers in TA muscle injected with Ad-VP22-MICDYS was 2.2 times more than that of TA muscle injected with Ad-MICDYS. Ad-VP22-MICDYS led to significant recovery of force-producing capabilities in TA muscle. These results demonstrate that VP22 greatly augmented adenovirus-mediated microdystrophin delivery to C2C12 cells and to the skeletal muscles of dystrophin-deficient (mdx) mice. These results highlight the efficiency of VP22-mediated intercellular protein delivery for the potential therapy of DMD and suggest that VP22 may be a promising tool with which to enhance the efficacy of adenoviral gene transfer for somatic gene therapy of DMD.
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PMID:Herpes simplex virus VP22 enhances adenovirus-mediated microdystrophin gene transfer to skeletal muscles in dystrophin-deficient (mdx) mice. 1755 Mar 36