Showing papers by "Beverly L. Davidson published in 2003"

Allele-specific silencing of dominant disease genes

Abstract: Small interfering RNA (siRNA) holds therapeutic promise for silencing dominantly acting disease genes, particularly if mutant alleles can be targeted selectively. In mammalian cell models we demonstrate that allele-specific silencing of disease genes with siRNA can be achieved by targeting either a linked single-nucleotide polymorphism (SNP) or the disease mutation directly. For a polyglutamine neurodegenerative disorder in which we first determined that selective targeting of the disease-causing CAG repeat is not possible, we took advantage of an associated SNP to generate siRNA that exclusively silenced the mutant Machado-Joseph disease/spinocerebellar ataxia type 3 allele while sparing expression of the WT allele. Allele-specific suppression was accomplished with all three approaches currently used to deliver siRNA: in vitro-synthesized duplexes as well as plasmid and viral expression of short hairpin RNA. We further optimized siRNA to specifically target a missense Tau mutation, V337M, that causes frontotemporal dementia. These studies establish that siRNA can be engineered to silence disease genes differing by a single nucleotide and highlight a key role for SNPs in extending the utility of siRNA in dominantly inherited disorders.

Identification of PDGFR as a receptor for AAV-5 transduction

Abstract: Understanding the process of vector transduction has important implications for the application and optimal use of a vector system for human gene therapy. Recent studies with vectors based on adeno-associated virus type 5 (AAV-5) have shown utility of this vector system in the lung, central nervous system, muscle and eye. To understand the natural tropism of this virus and to identify proteins necessary for AAV-5 transduction, we characterized 43 cell lines as permissive or nonpermissive for AAV-5 transduction and compared the gene expression profiles derived from cDNA microarray analyses of those cell lines. A statistically significant correlation was observed between expression of the platelet-derived growth factor receptor (PDGFR-alpha-polypeptide) and AAV-5 transduction. Subsequent experiments confirmed the role of PDGFR-alpha and PDGFR-beta as receptors for AAV-5. The tropism of AAV-5 in vivo also correlated with the expression pattern of PDGFR-alpha.

Viral vectors for gene delivery to the nervous system

Abstract: Our ability to manipulate the genetic constitution of the nervous system has come of age with various technologies, including virus vectors that can efficiently deliver genes to neurons and other neural cells in vitro and in vivo. These vectors allow us to monitor neurobiological functions, replace, correct, express or block expression of target genes, tag cells for fate determination, and change the physiological state of specific cell populations. The available vectors differ in their suitability for different applications, which depends on factors such as the size of the transgene, route of delivery, tropism, duration and regulation of gene expression, and side effects.

Lentivirus Vectors Pseudotyped with Filoviral Envelope Glycoproteins Transduce Airway Epithelia from the Apical Surface Independently of Folate Receptor Alpha

Abstract: The practical application of gene therapy as a treatment for cystic fibrosis is limited by poor gene transfer efficiency with vectors applied to the apical surface of airway epithelia. Recently, folate receptor alpha (FRα), a glycosylphosphatidylinositol-linked surface protein, was reported to be a cellular receptor for the filoviruses. We found that polarized human airway epithelia expressed abundant FRα on their apical surface. In an attempt to target these apical receptors, we pseudotyped feline immunodeficiency virus (FIV)-based vectors by using envelope glycoproteins (GPs) from the filoviruses Marburg virus and Ebola virus. Importantly, primary cultures of well-differentiated human airway epithelia were transduced when filovirus GP-pseudotyped FIV was applied to the apical surface. Furthermore, by deleting a heavily O-glycosylated extracellular domain of the Ebola GP, we improved the titer of concentrated vector severalfold. To investigate the folate receptor dependence of gene transfer with the filovirus pseudotypes, we compared gene transfer efficiency in immortalized airway epithelium cell lines and primary cultures. By utilizing phosphatidylinositol-specific phospholipase C (PI-PLC) treatment and FRα-blocking antibodies, we demonstrated FRα-dependent and -independent entry by filovirus glycoprotein-pseudotyped FIV-based vectors in airway epithelia. Of particular interest, entry independent of FRα was observed in primary cultures of human airway epithelia. Understanding viral vector binding and entry pathways is fundamental for developing cystic fibrosis gene therapy applications.

Infection efficiency of human and mouse embryonic stem cells using adenoviral and adeno-associated viral vectors.

Abstract: Human and mouse embryonic stem (ES) cells have the capacity to differentiate into derivatives of all three germ layers, suggesting novel therapies for degenerative, metabolic, and traumatic disorders. ES-based regenerative medicine will be further advanced by the development of reliable methods for transgene introduction and expression. Here, we show infection of human and mouse embryonic stem (ES) cells with two of the most popular vectors in gene transfer, adenovirus type 5 (Ad5) and adeno-associated virus (AAV; serotypes 2, 4, and 5). All vectors express the nuclear-localized marker gene beta-galactosidase expressed from the Rous Sarcoma Virus long terminal repeat (RSV-LTR). Both Ad5 and AAV2 infected human and mouse ES cells and gave rise to beta-galactosidase expression. AAV4 and 5 did not yield detectable levels of beta-galactosidase expression. Quantitative PCR analysis of virally infected human and mouse ES cells revealed that only Ad5 and AAV2 are capable of transducing both cell-types. No viral DNA was detected in cells infected with either AAV4 or AAV5. Infection and subsequent differentiation of mouse and human ES cells with Ad5 showed that beta-galactosidase-expressing cells were restricted to cells in the interior of the embryoid body mass. No beta-galactosidase expression was observed in AAV-infected cells following differentiation. There was no difference in morphology or differentiation patterns between infected and noninfected differentiating mouse and human ES cells. Differentiation of hES cells prior to infection led to transduction of neuronally differentiated cells with good efficiency using all vectors. These data show that Ad5- and AAV2-based vectors are capable of infecting both human and mouse ES cells, in both their undifferentiated and differentiated states, whereas AAV4 and AAV5 can infect human and mouse ES cells only following differentiation.

Adeno-associated virus type 5: transduction efficiency and cell-type specificity in the primate retina

Abstract: Gene transfer using adeno-associated viruses (AAVs) has been effective for treating inherited retinal diseases in animal models. Further evaluation in primates must be performed prior to clinical application, however, because of the difference between the retina of the primate and those of other animals. Prior work has shown that AAV2 can transduce rod-photoreceptor and RPE cells in the non-human primate retina and that AAV5 is more efficient at transducing photoreceptor cells than AAV2 in the rodent retina. In this study, we evaluated the efficiency of AAV5 in the non-human primate retina after subretinal injections of the vector to distinct anatomic retinal regions (superior, inferior, nasal, macula, temporal). rAAV5 led to a rapid onset of transgene expression (within 2 weeks), with expression persisting up to 10 months. Postoperative electrophysiology studies showed that global retinal function was preserved following gene transfer. Quantitative analysis of gene transfer demonstrated a maximum transduction efficiency of 22% in the injected areas. Evaluation of cell types using confocal microscopy and cone-specific antibodies revealed that AAV5, expressing reporter genes from the cytomegalovirus (CMV) promoter/enhancer, preferentially transduced rods. No significant differences were found in the regional tropism of AAV5 among the five areas injected despite variation in retinal topography. Immunohistochemical studies revealed that the AAV5 receptor, PDGFR-A, is localized to the outer segments of rods but not cones providing a basis for the observed tropism. Our results support the utility of AAV5 for rod photoreceptor degeneration therapies.

siRNA-mediated gene silencing with viral vectors

Abstract: The present invention is directed to viral vectors encoding small interfering RNA molecules (siRNA) targeted against a gene of interest, and methods of using these viral vectors.

Toward therapy for DYT1 dystonia: allele-specific silencing of mutant TorsinA.

Abstract: A three-nucleotide (GAG) deletion in the TOR1A gene is the most common cause of inherited dystonia, DYT1. Because the mutant protein, TorsinA (TA), is thought to act in a dominant manner to cause disease, inhibiting expression from the mutant gene represents a potentially powerful therapeutic strategy. In an effort to develop therapy for this disease, we tested whether small interfering RNA (siRNA) could selectively silence expression of mutant TA. Exploiting the three-base pair difference between wild-type and mutant alleles, we designed siRNAs to silence expression of mutant, wild-type, or both forms of TA. In transfected cells, siRNA successfully suppressed wild-type or mutant TA in an allele-specific manner: for example, mutant-specific siRNA reduced the levels of mutant TA to less than 1% of controls with minimal effect on wild-type TA expression. In cells expressing both alleles, thus simulating the heterozygous state, siRNA-mediated suppression remained robust and allele specific. Our siRNA studies demonstrate allele-specific targeting of a dominant neurogenetic disease gene and suggest the broad therapeutic potential of siRNA for DYT1 dystonia and other dominantly inherited neurological diseases.

Sirna-mediated gene silencing

Abstract: The present invention is directed to small interfering RNA molecules (siRNA) targeted against an allele of interest, and methods of using these siRNA molecules.

Viral-mediated delivery of the late-infantile neuronal ceroid lipofuscinosis gene, TPP-I to the mouse central nervous system.

Abstract: Classical late-infantile neuronal ceroid lipofuscinosis (LINCL) is caused by mutations in tripeptidyl peptidase I (TPP-I), a pepstatin-insensitive lysosomal protease, resulting in neurodegeneration, acute seizures, visual and motor dysfunction. In vitro studies suggest that TPP-I is secreted from cells and subsequently taken up by neighboring cells, similar to other lysosomal enzymes. As such, TPP-I is an attractive candidate for enzyme replacement or gene therapy. In the present studies, we examined the feasibility of gene transfer into mouse brain using recombinant adenovirus (Ad), feline immunodeficiency virus (FIV) and adeno-associated virus (AAV) vectors expressing TPP-I, after single injections into the striatum or cerebellum. A dual TPP-I- and β-galactosidase-expressing adenovirus vector (AdTTP-I/nlsβgal) was used to distinguish transduced (β-galactosidase positive) cells from cells that endocytosed secreted TTP-I. Ten days after striatal injection of AdTTP-I/nlsβgal, β-galactosidase-positive cells were concentrated around the injection site, corpus callosum, ependyma and choroid plexus. In cerebellar injections, β-galactosidase expression was confined to the region of injection and in isolated neurons of the brainstem. Immunohistochemistry for TPP-I expression showed that TPP-I extended beyond areas of β-galactosidase activity. Immunohistochemistry for TTP-I after FIVTTP-I and AAV5TTP-I injections demonstrated TPP-I in neurons of the striatum, hippocampus and Purkinje cells. For all three vectors, TPP-I activity in brain homogenates was 3–7-fold higher than endogenous levels in the injected hemispheres. Our results indicate the feasibility of vector-mediated gene transfer of TPP-I to the CNS as a potential therapy for LINCL.

Impact of human interleukin-10 on vector-induced inflammation and early graft function in rat lung transplantation.

Abstract: This study was undertaken to examine the time course of human interleukin (hIL)-10 gene expression after transtracheal administration of adenoviral (Ad)hIL-10 and its effect on the early adenoviral proinflammatory cytokine response and on post-transplant lung function. Using a rat lung transplant model, we observed that lungs retrieved 12 h after the administration of AdhIL-10 were associated with significant improvement in post-transplant lung function. Shorter periods of transfection were associated with significantly elevated levels of tumor necrosis factor-α and macrophage inflammatory protein-2 in lung tissue, leading to an increased degree of injury. The release of proinflammatory cytokines secondary to the adenoviral vector was reduced by high-dose methylprednisolone (30 mg/kg) administered 3 h before transfection. Reduction in the early adenoviral inflammatory response was associated with significant improvement in post-transplant lung function when lungs were retrieved 6 or 12 h after transtrache...

ALLELE-SPECIFIC siRNA-MEDIATED GENE SILENCING

Abstract: The present invention is directed to small interfering RNA molecules (siRNA) targeted against an allele of interest, and methods of using these siRNA molecules.

Hepatic diseases--hitting the target with inhibitory RNAs.

Abstract: A promising new method of silencing gene expression has been shown to be an effective therapy in two mouse models of autoimmune hepatitis and hepatitis B infection.

Tripeptide probes for tripeptidyl protease I production via gene transfer.

Abstract: Tripeptides derived from 5-chloroanthraquinone hydrazide and anthraquinone hydrazide have been prepared as potential reagents to probe cellular expression of tripeptidyl protease I (TPP-I). Attempt...

Methods for producing and using in vivo pseudotyped retroviruses using envelope glycoproteins from lymphocytic choriomeningitis virus (LCMV)

Abstract: The present invention provides novel pseudotyped retroviral vectors that can transduce human and other cells. Vectors are provided that are packaged efficiently in packaging cells and cell lines to generate high titer recombinant virus stocks expressing novel envelope glycoproteins. The present invention further relates to compositions for gene therapy.

Adenovirus serotype 30 (Ad30)

Abstract: The present invention provides an adenovirus serotype 30 (Ad30) fiber amino acid sequence. The present invention also provides polynucleotides and expression vectors encoding an Ad30 fiber and viral particles and cells containing such expression vectors. The present invention further provides methods of treating genetic diseases or cancers in a mammal using the polynucleotides, polypeptides, expression vectors, viral particles and cells of the present invention.

Compounds and methods for detecting tripeptidyl protease I

Abstract: The present invention provides compounds useful for the detection of the enzyme tripeptidyl protease I (TPP-1). The invention also provides methods of making such compounds, methods of using such compounds, and kits and compositions containing such compounds. In one embodiment, Gly-L-Pro-L-Ser-1-anthraquinonylhydrazide, in combination with p-anisaldehyde, is used to detect TPP-1.

Silen age genique a mediation par arnsi a l'aide de vecteurs viraux

Abstract: La presente invention concerne des vecteurs viraux codant des molecules d'ARN a faible interference (ARNsi) diriges contre un gene a etudier ainsi que des methodes d'utilisation desdits vecteurs viraux.

Silen age genique a mediation par arnsi specifique des alleles

Abstract: La presente invention concerne des molecules d'ARN a faible interference (ARNsi) dirigees contre un allele a etudier ainsi que des methodes d'utilisation desdites molecules ARNsi.