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Shirley TL, Lewers JC, Egami K, Majumdar A, Kelly M, Ceballos-Picot I, Seidman MM, Jinnah HA. A human neuronal tissue culture model for Lesch-Nyhan disease. J Neurochem 2007; 101:841-53. [PMID: 17448149 DOI: 10.1111/j.1471-4159.2007.04472.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mutations in the gene encoding the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause Lesch-Nyhan disease, a neurodevelopmental disorder characterized by cognitive, neurological, and behavioral abnormalities. Despite detailed knowledge of the enzyme's function, the key pathophysiological changes that accompany loss of purine recycling are unclear. To facilitate delineating the consequences of HPRT deficiency, four independent HPRT-deficient sublines of the human dopaminergic neuroblastoma, SK-N-BE(2) M17, were isolated by targeted mutagenesis with triple helix-forming oligonucleotides. As a group, these HPRT-deficient cells showed several significant abnormalities: (i) impaired purine recycling with accumulation of hypoxanthine, guanine, and xanthine, (ii) reduced guanylate energy charge and GTP:GDP ratio, but normal adenylate energy charge and no changes in any adenine nucleotide ratios, (iii) increased levels of UTP and NADP+, (iv) reduced DOPA decarboxylase, but normal monoamines, and (v) reduction in cell soma size. These cells combine the analytical power of multiple lines and a human, neuronal origin to provide an important tool to investigate the pathophysiology of HPRT deficiency.
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Affiliation(s)
- Thomas L Shirley
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA, and Department of Biology, Necker-Enfants Malades Hospital, Paris, France
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Barcia C, Gerdes C, Xiong WD, Thomas CE, Liu C, Kroeger KM, Castro MG, Lowenstein PR. Immunological thresholds in neurological gene therapy: highly efficient elimination of transduced cells might be related to the specific formation of immunological synapses between T cells and virus-infected brain cells. NEURON GLIA BIOLOGY 2006; 2:309-22. [PMID: 18084640 PMCID: PMC2139984 DOI: 10.1017/s1740925x07000579] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
First-generation adenovirus can be engineered with powerful promoters to drive expression of therapeutic transgenes. Numerous clinical trials for glioblastoma multiforme using first generation adenoviral vectors have either been performed or are ongoing, including an ongoing, Phase III, multicenter trial in Europe and Israel (Ark Therapeutics, Inc.). Although in the absence of anti-adenovirus immune responses expression in the brain lasts 6-18 months, systemic infection with adenovirus induces immune responses that inhibit dramatically therapeutic transgene expression from first generation adenoviral vectors, thus, potentially compromising therapeutic efficacy. Here, we show evidence of an immunization threshold for the dose that generates an immune response strong enough to eliminate transgene expression from the CNS. For the systemic immunization to eliminate transgene expression from the brain, > or = 1 x 10(7) infectious units (iu) of adenovirus need to be used as immunogen. Furthermore, this immune response eliminates >90% of transgene expression from 1 x 10(7)-1 x 10(3) iu of vector injected into the striatum 60 days earlier. Importantly, elimination of transgene expression is independent of the nature of the promoter that drives transgene expression and is accompanied by brain infiltration of CD8(+) T cells and macrophages. In conclusion, once the threshold for systemic immunization (i.e. 1 x 10(7) iu) is crossed, the immune response eliminates transgene expression by >90% even from brains that receive as little as 1000 iu of adenoviral vectors, independently of the type of promoter that drives expression.
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Affiliation(s)
- Carlos Barcia
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
| | - Christian Gerdes
- Molecular Medicine and Gene Therapy Unit, Room 1.302, Stopford Building, University of Manchester, UK
| | - Wei-Dong Xiong
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
| | - Clare E. Thomas
- Molecular Medicine and Gene Therapy Unit, Room 1.302, Stopford Building, University of Manchester, UK
| | - Chunyan Liu
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
| | - Kurt M. Kroeger
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
| | - Maria G. Castro
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
- Departments of Medicine and Molecular and Medical Pharmacology, David Gerfen School of Medicine, University of California Los Angeles, USA
| | - Pedro R. Lowenstein
- Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 5094, Los Angeles, USA
- Departments of Medicine and Molecular and Medical Pharmacology, David Gerfen School of Medicine, University of California Los Angeles, USA
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