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H J Federoff

Publications and source records attributed to H J Federoff.

At least 19 recordsLinked to original sources
PubMed2006

Isoform-specific effects of ApoE on HSV immediate early gene expression and establishment of latency.

Alzheimer's disease (AD) is a common and devastating neurodegenerative disease in which most cases are of unknown, sporadic origin. In addition to age, the most prevalent known risk factor for developing AD is carriage of the epsilon4 allele of Apolipoprotein E (ApoE). Carriage of the epsilon2 or epsilon3 allele of ApoE confers protection or no change in risk for AD, respectively. Latent herpes simplex virus type 1 (HSV-1) infection in the brain concurrent with ApoE4 carriage exacerbates risk for AD, suggesting that these two factors interact to promote neuronal dysfunction and degeneration in selective brain areas. Indeed, HSV-1 DNA has been found in regions primarily affected by AD, such as the temporal lobes, hippocampus, and neocortex. We hypothesize that HSV-1 infection in the background of ApoE4, but not ApoE2 or ApoE3, promotes an environment more conducive to neuronal degeneration. To investigate this idea, we have utilized transgenic mice that express human ApoE2, 3, or 4 alleles from astrocytes in a murine ApoE -/- background. We find that carriage of the different ApoE alleles dramatically affects HSV-1 immediate early gene expression as well as the establishment of latency. Both of these factors are poised to impact neuronal viability, inflammation, and viral spread. Our data support the concept that HSV-1 and ApoE4 interact to provide an environment conducive to the development and/or spread of AD.

Age Factors↗
PubMed2006

Synapsin I Cre transgene expression in male mice produces germline recombination in progeny.

The cre/LoxP system can produce conditional loss of gene function in specific cell types such as neurons. A transgenic mouse line, utilized by multiple studies, used the Synapsin I promoter to drive expression of cre (SynCre) to achieve neuronal-specific cre expression. Herein we describe that cre expression can also be observed in SynCre mice within the testes after being bred into a floxed transgenic mouse line. Cre transcript was expressed in testes resulting in recombination of the floxed substrate in testes. In the majority of cases, progeny of male SynCre mice inherited a germline recombined floxed allele, while this was never observed in progeny from female mice carrying the SynCre allele. This observation should alert investigators to a potential confound using these mice and enables male germ cell "deletor" strategies.

Animals↗
PubMed2006

Improved HSV-1 amplicon packaging using virion host shutoff mutants lacking mRNAse activity.

Given their generous transgene capacity and inherent neurotropism, herpes simplex virus (HSV-1)-based viral vectors are promising tools for gene delivery to the central nervous system. Despite their widespread pre-clinical use, vector toxicity remains a concern with regard to the use of herpes vectors in humans. One potential source of toxicity stems from the tegument-associated virion host shutoff protein (vhs), which induces translational arrest in the host cell through non-specific mRNAse activity. In the current study we utilized a series of HSV-1 viruses containing a deletion in the U(L)41 open reading frame to investigate: (1) the requirement of intact vhs function in amplicon packaging and (2) whether vhs influences the post-transduction survival of dissociated cortical neurons. Our results demonstrate that while amplicon yield was reduced an order of magnitude, U(L)41 deletion was associated with reduced vector toxicity. Furthermore, partial reconstitution of vhs function using mRNAse-inactive point mutants improved amplicon titers without imparting the toxicity observed with wild-type controls. These findings offer a novel approach to improving the titer and toxicity profiles of HSV-based viral vectors.

Animals↗
PubMed2005

Novel gene therapeutic strategies for neurodegenerative diseases.

The convergent pathobiologic model of Parkinson's disease stipulates that disparate insults initiate a disease process that obligately share a common pathway leading to cell death. A combinatorial treatment which targets various steps in this pathway is likely to be the most successful therapeutic strategy. As advances are made in the field of neuroimaging and pharmacogenomics, early detection of sporadic PD will become a reality. Early intervention will likely spare more dopaminergic neurons and extend the quality of life for the patient. Continued advancements in the fields of pharmacology, neurosurgery, and gene therapy will strengthen the armamentarium available for the treatment of PD patients.

Animals↗
PubMed2005

Temporal evolution of mouse striatal gene expression following MPTP injury.

The gradual loss of striatal dopamine and dopaminergic neurons residing in the substantia nigra (SN) causes parkinsonism characterized by slow, halting movements, rigidity, and resting tremor when neuronal loss exceeds a threshold of approximately 80%. It is estimated that there is extensive compensation for several years prior to symptom onset, during which vulnerable neurons asynchronously die. Recent evidence would argue that much of the compensatory response of the nigrostriatal system is multimodal including both pre-synaptic and striatal mechanisms. Although parkinsonism may have multiple causes, the classic syndrome, Parkinson's disease (PD), is frequently modeled in small animals by repeated administration of the selective neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Because the MPTP model of PD recapitulates many of the known behavioral and pathological features of human PD, we asked whether the striatal cells of mice treated with MPTP in a semi-chronic paradigm enact a transcriptional program that would help elucidate the response to dopamine denervation. Our findings reveal a time-dependent dysregulation in the striatum of a set of genes whose products may impact both the viability and ability to communicate of dopamine neurons in the SN.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2003

HSV amplicon delivery of glial cell line-derived neurotrophic factor is neuroprotective against ischemic injury.

Direct intracerebral administration of glial cell line-derived neurotrophic factor (GDNF) is neuroprotective against ischemia-induced cerebral injury. Utilizing viral vectors to deliver and express therapeutic genes presents an opportunity to produce GDNF within localized regions of an evolving infarct. We investigated whether a herpes simplex virus (HSV) amplicon-based vector encoding GDNF (HSVgdnf) would protect neurons against ischemic injury. In primary cortical cultures HSVgdnf reduced oxidant-induced injury compared to the control vector HSVlac. To test protective effects in vivo, HSVgdnf or HSVlac was injected into the cerebral cortex 4 days prior to, or 3 days, after a 60-min unilateral occlusion of the middle cerebral artery. Control stroke animals developed bradykinesia and motor asymmetry; pretreatment with HSVgdnf significantly reduced such motor deficits. Animals receiving HSVlac or HSVgdnf after the ischemic insult did not exhibit any behavioral improvement. Histological analyses performed 1 month after stroke revealed a reduction in ischemic tissue loss in rats pretreated with HSVgdnf. Similarly, these animals exhibited less immunostaining for glial fibrillary acidic protein and the apoptotic marker caspase-3. Taken together, our data indicate that HSVgdnf pretreatment provides protection against cerebral ischemia and supports the utilization of the HSV amplicon for therapeutic delivery of trophic factors to the CNS.

Animals↗
PubMed2003

Immune responses to replication-defective HSV-1 type vectors within the CNS: implications for gene therapy.

Herpes simplex virus (HSV) is a naturally occurring double-stranded DNA virus that has been adapted into an efficient vector for in vivo gene transfer. HSV-based vectors exhibit wide tropism, large transgene size capacity, and moderately prolonged transgene expression profiles. Clinical implementation of HSV vector-based gene therapy for prevention and/or amelioration of human diseases eventually will be realized, but inherently this goal presents a series of significant challenges, one of which relates to issues of immune system involvement. Few experimental reports have detailed HSV vector-engendered immune responses and subsequent resolution events primarily within the confines of the central nervous system. Herein, we describe the immunobiology of HSV and its derived vector platforms, thus providing an initiation point from where to propose requisite experimental investigation and potential approaches to prevent and/or counter adverse antivector immune responses.

Animals↗
PubMed2001

Dendritic cells transduced with HSV-1 amplicons expressing prostate-specific antigen generate antitumor immunity in mice.

There is currently much interest in generating cytotoxic T lymphocyte (CTL) responses against tumor antigens as a therapy for cancer. This work describes a novel gene transfer technique utilizing dendritic cells (DCs), an extremely potent form of antigen-presenting cell (APC), and herpes simplex virus-1 (HSV-1) amplicons. HSV-1 amplicons are plasmid-based viral vectors that are packaged into HSV-1 capsids, but lack viral coding sequences. Amplicon vectors have been constructed that encode the model tumor antigen ovalbumin (HSV-OVA) and human prostate-specific antigen (HSV-PSA), a protein that is expressed specifically in prostate epithelium and prostate carcinoma cells. These amplicons were packaged using a helper virus-free system that produces vector stocks that are devoid of contaminating cytotoxic helper virus. Transduction of DCs with HSV-OVA or HSV-PSA and co-culture with CTL hybridomas results in specific activation, indicating that transduced DCs express these transgenes and process the tumor antigens for class I MHC presentation to CTL. Mice immunized with HSV-PSA-transduced DCs generate a specific CTL response that can be detected in vitro by a (51)Cr-release assay and are protected from challenge with tumors that express PSA. These results indicate that DCs transduced with HSV-1 amplicon vectors may provide a tool for investigation of the biology of CTL activation by DCs and a new modality for immunotherapy of cancer.

Animals↗
PubMed2001

Regulation of neuronal traits by a novel transcriptional complex.

The transcriptional repressor, REST, helps restrict neuronal traits to neurons by blocking their expression in nonneuronal cells. To examine the repercussions of REST expression in neurons, we generated a neuronal cell line that expresses REST conditionally. REST expression inhibited differentiation by nerve growth factor, suppressing both sodium current and neurite growth. A novel corepressor complex, CoREST/HDAC2, was shown to be required for REST repression. In the presence of REST, the CoREST/HDAC2 complex occupied the native Nav1.2 sodium channel gene in chromatin. In neuronal cells that lack REST and express sodium channels, the corepressor complex was not present on the gene. Collectively, these studies define a novel HDAC complex that is recruited by the C-terminal repressor domain of REST to actively repress genes essential to the neuronal phenotype.

Animals↗
PubMed2001

Development of herpes simplex virus-1 amplicon-based immunotherapy for chronic lymphocytic leukemia.

Herpes simplex virus (HSV)-based vectors have favorable biologic features for gene therapy of leukemia and lymphoma. These include high transduction efficiency, ability to infect postmitotic cells, and large packaging capacity. The usefulness of HSV amplicon vectors for the transduction of primary human B-cell chronic lymphocytic leukemia (CLL) was explored. Vectors were constructed encoding beta-galactosidase (LacZ), CD80 (B7.1), or CD154 (CD40L) and were packaged using either a standard helper virus (HSVlac, HSVB7.1, and HSVCD40L) or a helper virus-free method (hf-HSVlac, hf-HSVB7.1, and hf-HSVCD40L). Both helper-containing and helper-free vector stocks were studied for their ability to transduce CLL cells, up-regulate costimulatory molecules, stimulate allogeneic T-cell proliferation in a mixed lymphocyte tumor reaction, and generate autologous cytotoxic T lymphocytes (CTLs). Although helper-containing and helper-free amplicon stocks were equivalent in their ability to transduce CLL cells, a vigorous T-cell proliferative response was obtained using cells transduced with hf-HSVB7.1 but not with HSVB7.1. CLL cells transduced with either HSVCD40L or hf-HSVCD40L were compared for their ability to up-regulate resident B7.1 and to function as T-cell stimulators. Significantly enhanced B7.1 expression in response to CD40L was observed using hf-HSVCD40L but not with HSVCD40L. CLL cells transduced with hf-HSVCD40L were also more effective at stimulating T-cell proliferation than those transduced with HSVCD40L stocks and were successful in stimulating autologous CTL activity. It is concluded that HSV amplicons are efficient vectors for gene therapy of hematologic malignancies and that helper virus-free HSV amplicon preparations are better suited for immunotherapy.

Antigen-Presenting Cells↗
PubMed2001

Modulation of the neuronal glutamate transporter EAAT4 by two interacting proteins.

Glutamate is the main excitatory neurotransmitter in the mammalian central nervous system and is removed from the synaptic cleft by sodium-dependent glutamate transporters. To date, five distinct glutamate transporters have been cloned from animal and human tissue: GLAST (EAAT1), GLT-1 (EAAT2), EAAC1 (EAAT3), EAAT4, and EAAT5 (refs 1-5). GLAST and GLT-1 are localized primarily in astrocytes, whereas EAAC1 (refs 8, 9), EAAT4 (refs 9-11) and EAAT5 (ref 5) are neuronal. Studies of EAAT4 and EAAC1 indicate an extrasynaptic localization on perisynaptic membranes that are near release sites. This localization facilitates rapid glutamate binding, and may have a role in shaping the amplitude of postsynaptic responses in densely packed cerebellar terminals. We have used a yeast two-hybrid screen to identify interacting proteins that may be involved in regulating EAAT4--the glutamate transporter expressed predominately in the cerebellum--or in targeting and/or anchoring or clustering the transporter to the target site. Here we report the identification and characterization of two proteins, GTRAP41 and GTRAP48 (for glutamate transporter EAAT4 associated protein) that specifically interact with the intracellular carboxy-terminal domain of EAAT4 and modulate its glutamate transport activity.

Amino Acid Sequence↗
PubMed2001

HSV amplicon-mediated neurotrophin-3 expression protects murine spiral ganglion neurons from cisplatin-induced damage.

Ototoxicity is a major dose-limiting side effect of cisplatin (DDP) administration due to its propensity to induce destruction of hair cells and neurons in the auditory system. Previous studies demonstrated that TrkC-expressing spiral ganglion neurons (SGN) are protected from the cytotoxic effects of DDP by localized delivery of the trophic factor neurotrophin-3 (NT-3). Successful in vivo implementation of such a therapy requires the development of an efficient gene delivery vehicle for expression of NT-3 within the cochlea. To this end, we constructed a herpes simplex virus (HSV) amplicon vector that expressed a c-Myc-tagged NT-3 chimera (HSVnt-3myc). Helper virus-free vector stocks were initially evaluated in vitro for their capacity to direct expression of NT-3 mRNA and protein. Transduction of cultured murine cochlear explants with HSVnt-3myc resulted in production of NT-3 mRNA and protein up to 3 ng/ml as measured over a 48-h period in culture supernatants. To determine whether NT-3 overexpression could abrogate DDP toxicity, cochlear explants were transduced with HSVnt-3myc or a murine intestinal alkaline phosphatase-expressing control vector, HSVmiap, and then exposed to cisplatin. HSVnt-3myc-transduced cochlear explants harbored significantly greater numbers of surviving SGNs than those infected with control virus. These data demonstrate that amplicon-mediated NT-3 transduction can attenuate the ototoxic action of DDP on organotypic culture. The potency of NT-3 in protecting spiral ganglion neurons from degeneration suggests that in vivo neurotrophin-based gene therapy may be useful for the prevention and/or treatment of hearing disorders.

Animals↗
PubMed2001

A novel approach to cancer therapy using an oncolytic herpes virus to package amplicons containing cytokine genes.

There are two promising herpes viral-based anticancer strategies: one involves replication-defective viruses to transfer therapeutic transgenes, and the other involves replication-conditional oncolytic viruses, which selectively infect and destroy cancer cells directly. This study examines a novel dual herpesvirus preparation, which combines the immunostimulatory effects of amplicon-mediated IL2 expression with direct viral-induced oncolysis. The oncolytic virus G207 was used as the helper virus to package a herpes simplex virus (HSV)-amplicon vector carrying the gene IL2 (HSV-IL2), yielding a single preparation with two complementary modes of action. In vivo comparison was carried out in a syngeneic squamous cell carcinoma flank tumor model. We directly injected established tumors with HSV-IL2, G207, G207 mixed with HSV-IL2, or G207-packaged HSV-amplicon carrying the IL2 transgene (G207[IL2]). Significant inhibition of tumor growth was seen at 2 weeks in the G207[IL2]-treated tumors relative to controls (0.57+/-0.44 cm(3) versus 39.45+/-5.13 cm(3), P<0.00001), HSV-IL2 (20.97+/-4.60 cm(3)), and the G207 group (7.71+/-2.10 cm(3)). This unique use of a replication-conditional, oncolytic virus to package a replication-incompetent amplicon vector demonstrates impressive efficacy in vitro and in vivo, and avoids the theoretical concerns of recombination with reversion to wild type.

Animals↗
PubMed2001

Expression of vhs and VP16 during HSV-1 helper virus-free amplicon packaging enhances titers.

Recently developed helper virus-free methods of herpes simplex virus (HSV) amplicon vector packaging provide stocks that are virtually devoid of the cytotoxic component normally associated with traditional helper virus-based packaging methods. These approaches involve cotransfection of amplicon plasmid DNA with either a five-cosmid set or a bacterial artificial chromosome (BAC) that contains the HSV genome without its cognate pac signals. Helper virus-free amplicon packaging produces low-titer stocks (<10(5) expressing particles/ml) that exhibit a high frequency of pseudotransduction. In an effort to enhance amplicon titers, we introduced in trans a genomic copy of the virion host shutoff (vhs) protein-encoding gene UL41 into both cosmid- and BAC-based packaging strategies. Cotransfection of this plasmid with the amplicon and packaging reagents results in a 10-fold higher amplicon titer, and stocks that do not exhibit the pseudotransduction phenomenon. To further enhance packaging efficiency, the HSV transcriptional activator VP16 was introduced into packaging cells 1 day before the packaging components. Pre-loading of packaging cells with VP16 led to an additional enhancement of amplicon titers, an effect that did not occur in the absence of vhs. Increased helper virus-free amplicon titers resulting from these modifications will make in vivo transduction experiments more feasible.

Animals↗
PubMed2001

Specific organ gene transfer in vivo by regional organ perfusion with herpes viral amplicon vectors: implications for local gene therapy.

BACKGROUND: Many gene therapy strategies would benefit from efficient, regional organ delivery of therapeutic genes. METHODS: Regional perfusions of lung, liver, or bladder were performed to determine if rapid and efficient gene transfer can be accomplished in vivo, and to determine if in vivo gene transfer can be limited to the organ of interest. In addition, herpes simplex virus tumor necrosis factor (HSVtnf), carrying the human tumor necrosis factoralpha gene was used as a treatment for methylcholanthrene sarcoma in a syngeneic lung metastases model in Fisher rats. RESULTS: A 20-minute perfusion using HSV carrying beta-galactosidase (HSVlac) produced significant expression of this marker gene isolated to the target organs, without organ-specific tissue injury or inflammation. Regional perfusion of organs with HSV carrying the cytokine gene tumor necrosis factor alpha also resulted in high-level local organ production of this cytokine (2851 +/- 53 pg/g tissue in perfused lung versus 0 for the contralateral lung). For the current vector construct, expression of the gene of interest peaked between 2 and 4 days and was undetectable by 2 weeks after perfusion. In animals undergoing perfusion as treatment for pulmonary sarcoma, there was no difference between tumor counts in lungs perfused with HSVlac (17 +/- 6) or HSVtnf (22 +/- 8), but either treatment resulted in lower tumor counts than controls (111 +/- 24 nodules per lung, P <.02). CONCLUSIONS: Regional organ perfusion using herpes viral vectors is an effective and well-tolerated in vivo method of transiently delivering potentially toxic gene products to target organs in directing gene therapy. Regional lung perfusion with HSV amplicons reduces tumor burden in a rat model of pulmonary metastases, though HSVtnf cannot be demonstrated to augment the cytopathic effect of the HSV amplicon alone in the current model.

Animals↗