Viral vectors for gene delivery to the nervous system.
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Animals↗
Biomedical subjects
Beverly L Davidson
Publications and source records attributed to Beverly L Davidson.
Lentivirus vectors pseudotyped with filoviral envelope glycoproteins transduce airway epithelia from the apical surface independently of folate receptor alpha.
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 (FR alpha), a glycosylphosphatidylinositol-linked surface protein, was reported to be a cellular receptor for the filoviruses. We found that polarized human airway epithelia expressed abundant FR alpha 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 FR alpha-blocking antibodies, we demonstrated FR alpha-dependent and -independent entry by filovirus glycoprotein-pseudotyped FIV-based vectors in airway epithelia. Of particular interest, entry independent of FR alpha 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.
Animals↗
Impact of human interleukin-10 on vector-induced inflammation and early graft function in rat lung transplantation.
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-alpha 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 transtracheal administration of AdhIL-10. Transtracheal administration of adenoviral-mediated hIL-10 to donor lungs is associated with a significant early inflammatory response that may enhance ischemia-reperfusion injury if insufficient hIL-10 is expressed in lung tissue before retrieval. The period between delivery of AdhIL-10 and lung retrieval can be reduced if the early inflammatory response is suppressed with methylprednisolone.
Adenoviridae↗
Recombinant adeno-associated viral vector types 4 and 5. Preparation and application for CNS gene transfer.
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Animals↗
siRNA-mediated gene silencing in vitro and in vivo.
RNA interference is now established as an important biological strategy for gene silencing, but its application to mammalian cells has been limited by nonspecific inhibitory effects of long dsRNA on translation. Here, we describe a viral-mediated delivery mechanism that results in specific silencing of targeted genes through expression of small interfering RNA (siRNA). We establish proof of principle by markedly diminishing expression of exogenous and endogenous genes in vitro and in vivo in brain and liver, and further apply this strategy to a model system of a major class of neurodegenerative disorders, the polyglutamine diseases, to show reduced polyglutamine aggregation in cells. This viral-mediated strategy should prove generally useful in reducing expression of target genes to model biological processes or to provide therapy for dominant human diseases.
Adenoviridae↗
Functional correction of established central nervous system deficits in an animal model of lysosomal storage disease with feline immunodeficiency virus-based vectors.
Gene transfer vectors based on lentiviruses can transduce terminally differentiated cells in the brain; however, their ability to reverse established behavioral deficits in animal models of neurodegeneration has not previously been tested. When recombinant feline immunodeficiency virus (FIV)-based vectors expressing beta-glucuronidase were unilaterally injected into the striatum of adult beta-glucuronidase deficient [mucopolysaccharidosis type VII (MPS VII)] mice, an animal model of lysosomal storage disease, there was bihemispheric correction of the characteristic cellular pathology. Moreover, after the injection of FIV-based vectors expressing beta-glucuronidase into brains of beta-glucuronidase-deficient mice with established impairments in spatial learning and memory, there was dramatic recovery of behavioral function. Cognitive improvement resulting from expression of beta-glucuronidase was associated with alteration in expression of genes associated with neuronal plasticity. These data suggest that enzyme replacement to the MPS VII central nervous system goes beyond restoration of beta-glucuronidase activity in the lysosome, and imparts improvements in plasticity and spatial learning.
Animals↗
Gene transfer to the nonhuman primate retina with recombinant feline immunodeficiency virus vectors.
We hypothesize that recombinant feline immunodeficiency viral (rFIV) vectors may be useful for gene transfer to the nonhuman primate retina. We performed vitrectomies and subretinal injections in the right eyes of 11 cynomolgus monkeys. Vesicular stomatitis virus glycoprotein-pseudotyped rFIV that expressed the Escherichia coli beta-galactosidase gene was injected into eight eyes. Sham vehicle or lactose buffer injections were also performed in two of these eight study eyes. rFIV pseudotyped with an amphotropic envelope was used in two eyes, and in one animal injections of lactose buffer only were given. After surgery the animals were clinically evaluated by retinal photography and electroretinography. beta-Galactosidase expression was evaluated, at a final end point, in histological sections. We found photoreceptor and Müller cells to have the greatest transgene expression. Focal inflammatory responses localized to the injection site were seen histologically in all eyes. No difference in transduction efficiency was seen between injections near the macula and more peripheral injections. Visual function as assessed by electroretinography was not significantly affected by vector or vehicle injections. We conclude that rFIV vectors administered beneath the retina can transduce a variety of retinal cells in the nonhuman primate retina. rFIV vectors have therapeutic potential and could be exploited to develop gene therapy for the human eye.
Animals↗
Widespread dispersal of cholera toxin subunit b to brain and spinal cord neurons following systemic delivery.
We have discovered novel transport properties of cholera toxin subunit b beyond well-known anterograde and retrograde axonal transport. Injection of 1500 microg of CTb intraperitoneally or intravenously in young adult mice resulted in generalized enhanced labeling of motor nuclei at all levels of the brain stem and spinal cord (oculomotor, trochlear, abducens, facial, trigeminal, vagal, hypoglossal, cervical, and lumbar). There was also extensive labeling of trigeminal and spinal primary afferent fibers, bulk labeling of the area postrema, and finally numerous labeled neurons in the periventricular and supraoptic hypothalamic nuclei. Generalized labeling of motor, sensory, and hypothalamic neurons could also be produced on a more limited scale from intramuscular injections of 500 microg of CTb in the tongue. Neuronal uptake of peripherally administered CTb may be useful as a research tool, or, when fused to therapeutic peptides, enzymes, growth factors, or gene therapy vectors, may have application in amyotrophic lateral sclerosis, diabetic neuropathy, motor neuronopathic lysosomal storage diseases, and other neurodegenerative disorders.
Adjuvants, Immunologic↗
Viral-mediated gene transfer to mouse primary neural progenitor cells.
Neural progenitor cells may provide for cell replacement or gene delivery vehicles in neurodegen-erative disease therapies. The expression of therapeutic proteins by neural progenitors would be enhanced by viral-mediated gene transfer, but the effects of several common recombinant viruses on primary progenitor cell populations have not been tested. To address this issue, we cultured cells from embryonic day 16-18 mouse brain in serum-free medium containing epidermal growth factor or basic fibroblast growth factor, and investigated how transduction with recombinant viral vectors affected maintenance and differentiation properties of progenitor cells. Neurosphere cultures were incubated with feline immunodeficiency virus (FIV), adeno-associated virus (AAV) or ade-noviral (Ad) constructs expressing either beta-galactosidase or enhanced green fluorescent protein at low multiplicity of infection. Nestin-positive neurospheres were regenerated after incubation of single progenitor cells with FIV, indicating that FIV-mediated gene transfer did not inhibit progenitor cell self-renewal. In contrast, adenovirus induced differentiation into glial fibrillary acidic protein (GFAP)-positive astrocytes. The AAV serotypes tested did not effectively transduce progenitor cells. FIV-transduced progenitors retained the potential for differentiation into neurons and glia in vitro, and when transplanted into the striatum of normal adult C57BL/6 mice differentiated into glia, or remained undifferentiated. In the presence of tumor cells, FIV-transduced progenitors migrated significantly from the injection site. Our results suggest that FIV-based vectors can transduce progenitor cell populations in vitro, with maintenance of their ability to differentiate into multiple cell types or to respond to injury within the central nervous system. These results hold promise for the use of genetically manipulated stem cells for CNS therapies.
Adenoviridae↗
Gene transfer to the brain using feline immunodeficiency virus-based lentivirus vectors.
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Animals↗
Virus-mediated transduction of murine retina with adeno-associated virus: effects of viral capsid and genome size.
Gene therapy vectors based on adeno-associated viruses (AAVs) show promise for the treatment of retinal degenerative diseases. In prior work, subretinal injections of AAV2, AAV5, and AAV2 pseudotyped with AAV5 capsids (AAV2/5) showed variable retinal pigmented epithelium (RPE) and photoreceptor cell transduction, while AAV2/1 predominantly transduced the RPE. To more thoroughly compare the efficiencies of gene transfer of AAV2, AAV3, AAV5, and AAV6, we quantified, using stereological methods, the kinetics and efficiency of AAV transduction to mouse photoreceptor cells. We observed persistent photoreceptor and RPE transduction by AAV5 and AAV2 up to 31 weeks and found that AAV5 transduced a greater volume than AAV2. AAV5 containing full-length or half-length genomes and AAV2/5 transduced comparable numbers of photoreceptor cells with similar rates of onset of expression. Compared to AAV2, AAV5 transduced significantly greater numbers of photoreceptor cells at 5 and 15 weeks after surgery (greater than 1,000 times and up to 400 times more, respectively). Also, there were 30 times more genome copies in eyes injected with AAV2/5 than in eyes injected with AAV2. Comparing AAVs with half-length genomes, AAV5 transduced only four times more photoreceptor cells than AAV2 at 5 weeks and nearly equivalent numbers at 15 weeks. The enhancement of transduction was seen at the DNA level, with 50 times more viral genome copies in retinas injected with AAV having short genomes than in retinas injected with AAV containing full-length ones. Subretinal injection of AAV2/6 showed only RPE transduction at 5 and 15 weeks, while AAV2/3 did not transduce retinal cells. We conclude that varying genome length and AAV capsids may allow for improved expression and/or gene transfer to specific cell types in the retina.
Animals↗
In vivo gene transfer using a nonprimate lentiviral vector pseudotyped with Ross River Virus glycoproteins.
Vectors derived from lentiviruses provide a promising gene delivery system. We examined the in vivo gene transfer efficiency and tissue or cell tropism of a feline immunodeficiency virus (FIV)-based lentiviral vector pseudotyped with the glycoproteins from Ross River Virus (RRV). RRV glycoproteins were efficiently incorporated into FIV virions, generating preparations of FIV vector, which after concentration attain titers up to 1.5 x 10(8) TU/ml. After systemic administration, RRV-pseudotyped FIV vectors (RRV/FIV) predominantly transduced the liver of recipient mice. Transduction efficiency in the liver with the RRV/FIV was ca. 20-fold higher than that achieved with the vesicular stomatitis virus G protein (VSV-G) pseudotype. Moreover, in comparison to VSV-G, the RRV glycoproteins caused less cytotoxicity, as determined from the levels of glutamic pyruvic transaminase and glutamic oxalacetic transaminase in serum. Although hepatocytes were the main liver cell type transduced, nonhepatocytes (mainly Kupffer cells) were also transduced. The percentages of the transduced nonhepatocytes were comparable between RRV and VSV-G pseudotypes and did not correlate with the production of antibody against the transgene product. After injection into brain, RRV/FIV preferentially transduced neuroglial cells (astrocytes and oligodendrocytes). In contrast to the VSV-G protein that targets predominantly neurons, <10% of the brain cells transduced with the RRV pseudotyped vector were neurons. Finally, the gene transfer efficiencies of RRV/FIV after direct application to skeletal muscle or airway were also examined and, although transgene-expressing cells were detected, their proportions were low. Our data support the utility of RRV glycoprotein-pseudotyped FIV lentiviral vectors for hepatocyte- and neuroglia-related disease applications.
Animals↗
Adenovirus serotype 30 fiber does not mediate transduction via the coxsackie-adenovirus receptor.
Prior work by members of our laboratory and others demonstrated that adenovirus serotype 30 (Ad30), a group D adenovirus, exhibited novel transduction characteristics compared to those of serotype 5 (Ad5, belonging to group C). While some serotype D adenoviruses bind to the coxsackie-adenovirus receptor (CAR), the ability of Ad30 fiber to bind CAR is unknown. We amplified and purified Ad30 and cloned the Ad30 fiber by overlap PCR. Alignment of Ad30 fiber with Ad3, Ad35, Ad5, Ad9, and Ad17 revealed that Ad30, like Ad9 and Ad17, has a shortened fiber sequence relative to that of Ad5. The knob region of fiber was 45% identical to that of the Ad5 knob regions. We made a chimeric recombinant virus (Ad5GFPf30) in which the Ad5 fiber (amino acids [aa]47 to 582) was replaced with Ad30 fiber sequences (aa 46 to 372), and CAR-mediated viral entry was determined on CAR-expressing Chinese hamster ovary (CHO) cells. While CAR expression significantly increased Ad5GFP-mediated transduction in CHO cells (from 1 to 36%), it did not enhance Ad5GFPf30 gene transfer. Binding of radiolabeled Ad5GFPf30 or Ad30 wild-type virus was also not improved by the expression of CAR. These results suggest that Ad30 fiber is distinct from Ad5, Ad9, and Ad17 fibers in its inability to direct transduction via CAR.
Adenoviruses, Human↗
Selective gene transfer to key cardiovascular regions of the brain: comparison of two viral vector systems.
The systemic renin-angiotensin system (RAS) plays a critical role in cardiovascular (CV) homeostasis. All components of the RAS are also known to be produced cell-specifically within specific brain regions, although the role of the brain RAS relative to the systemic RAS has remained a puzzle due to the difficulty of dissecting these two systems. Selectively targeting these regions with genes that modify the RAS could help unravel this puzzle. We compared the ability of adenovirus (Ad) and lentivirus (feline immunodeficiency virus, FIV) vectors to mediate gene delivery in vivo to the supraoptic nucleus (SON) and subfornical organ (SFO), two important CV control regions known to express the various RAS genes. SON or SFO of adult C57BL/6 mice (n=37) were stereotaxically injected with replication-deficient recombinant Ad or FIV harboring a beta-galactosidase (beta-gal) reporter gene. At 1, 3, or 8 weeks post-injection, brain sections were processed for beta-Gal activity, double immunofluorescence to verify cell-type specificity of viral transduction, or immunohistochemical detection of inflammatory mediators. Our results demonstrate that: (1) murine SFO and SON can be selectively targeted for gene transfer in vivo;(2) FIV mediated neuron-specific gene delivery, whereas Ad transduced both neuronal and glial cell types in SFO and SON; (3) Ad injected into the SON transduced neurons within the SFO through retrograde transport, whereas FIV did not; (4) beta-gal activity remained stable for 3 weeks but then declined by 8 weeks with Ad, while minimal decline occurred with FIV; (5) FIV did not cause inflammatory responses, whereas infiltrate was detectable in Ad-injected SFO and SON. These vectors are potentially important tools for dissecting the cell- and site-specific components of the brain RAS and other important CV regulatory systems within this circuitry, and may have therapeutic applications for centrally mediated CV diseases.
Adenoviridae↗
Feline immunodeficiency virus vectors. Gene transfer to mouse retina following intravitreal injection.
BACKGROUND: Transduction of the murine retinal pigmented epithelium (RPE) with adenovirus vectors requires technically difficult and invasive subretinal injections. This study tested the hypothesis that recombinant vectors based on feline immunodeficiency virus (FIV) could access the retina following intravitreal injection. METHODS: FIV vectors expressing E. coli beta-galactosidase (FIVbetagal) were injected alone, or in combination with adenovirus vectors expressing eGFP, into the vitreous of normal mice and eyes evaluated for transgene expression. In further studies, the utility of FIV-mediated gene transfer to correct lysosomal storage defects in the anterior and posterior chambers of eyes was tested using recombinant FIV vectors expressing beta-glucuronidase. FIVbetagluc vectors were injected into beta-glucuronidase-deficient mice, an animal model of mucopolysacharridoses type VII. RESULTS: The results of this study show that similar to adenovirus, both corneal endothelium and cells of the iris could be transduced following intravitreal injection of FIVbetagal. However, in contrast to adenovirus, intravitreal injection of FIVbetagal also resulted in transduction of the RPE. Immunohistochemistry following an intravitreal injection of an AdeGFP (adenovirus expressing green fluorescent protein) and FIVbetagal mixture confirmed that both viruses mediated transduction of corneal endothelium and cells of the iris, while only FIVbetagal transduced cells in the retina. Using the beta-glucuronidase-deficient mouse, the therapeutic efficacy of intravitreal injection of FIVbetagluc (FIV expressing beta-glucuronidase) was tested. Intravitreal injection of FIVbetagluc to the eyes of beta-glucuronidase-deficient mice resulted in rapid reduction (within 2 weeks) of the lysosomal storage defect within the RPE, corneal endothelium, and the non-pigmented epithelium of the ciliary process. Transgene expression and correction of the lysosomal storage defect remained for at least 12 weeks, the latest time point tested. CONCLUSION: These studies demonstrate that intravitreal injection of FIV-based vectors can mediate efficient and lasting transduction of cells in the cornea, iris, and retina.
Animals↗