Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed optimized versions of a conditionally replicating human immunodeficiency virus type 1 (HIV-1)-based lentiviral vector for gene therapy of HIV-1 infection. These vectors target HIV-1 RNAs containing sequences of the envelope gene by expressing a 1-kb fragment of the HIV-1 Tat/Rev intron in the antisense orientation. Expression of the envelope antisense gene (envAS) was evaluated under the control of different internal promoters such as the human phosphoglycerate kinase (PGK) promoter, the human EF1-alpha promoter, and the U3 region of the SL3 murine leukemia virus. The U3-SL3 promoter transactivates transcription from the vector HIV-1 LTR and drives higher expression levels of envAS-containing RNAs than other promoters in T-cell lines. The effect of other vector structural features was also evaluated. We found that the central polypurine tract and central termination sequence (cPPT) produce a small increase in vector infectivity of 2-fold to 3-fold and results in a 10-fold higher inhibition of wild-type viral replication in challenge experiments. The woodchuck hepatitis posttranscriptional regulatory element (WPRE) does not increase the cytoplasmic levels of envAS mRNA in T-cell lines. We observed that SupT1 and primary CD4(+) T cells transduced with these vectors showed high inhibition of HIV-1 replication, suppression of syncitium formation, and increased cell viability when infected with several HIV-1 laboratory strains. Our results suggest that higher vector copy number and increased levels of envAS RNA expression contribute to block replication of divergent strains of HIV-1.
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PMID:Enhanced inhibition of human immunodeficiency virus type 1 replication by novel lentiviral vectors expressing human immunodeficiency virus type 1 envelope antisense RNA. 1206 36

Despite important advances in human therapeutics, no specific treatment for both non-functioning gonadotroph and resistant somatotroph adenomas is available. Gene transfer by viral vectors can be considered as a promising way to achieve a specific and efficient treatment. Here we show the possibility of efficient gene transfer in human pituitary adenoma cells in vitro using a human immunodeficiency virus (HIV)-type 1-derived vector. Using enhanced green fluorescent protein (eGFP) gene as a marker placed under the phosphoglycerate kinase (PGK) promoter, gonadotroph and somatotroph adenomas were transduced even with moderate viral loads. The expression started at day 2, reached a peak at day 5, and it was still present at day 90. For targeting somatotroph and gonadotroph adenomas, human growth hormone (GH) promoter (GH -481, +54 bp) and two fragments of the human glycoprotein hormone alpha-subunit promoter (alpha-subunit 1 -520, +33 bp, and alpha-subunit 2 -907, +33 bp) were tested. In gonadotroph adenomas, the percentage of identified fluorescent cells and the fluorescence intensity analyzed by fluorescence-activated cell sorting indicated that the strength of the alpha-subunit 1 and alpha-subunit 2 promoters were comparable to that of the PGK promoter. Primary cultures of rat pituitary cells showed that alpha-subunit 1 is more selective to thyreotroph and gonadotroph phenotypes than alpha-subunit 2. GH promoter activity appeared weak in somatotroph adenomas. The human GH enhancer did not increase the GH promoter activity at all but the human prolactin promoter (-250 bp) allowed 4-fold more fluorescent cells to be obtained than the GH promoter. Several cell lines appeared too permissive to test cell-specificity of pituitary promoters. However, on human non-pituitary cell cultures, the tested pituitary promoters seemed clearly selective to target endocrine pituitary phenotypes. This study gives a starting point for a gene-therapy program using lentiviral vectors to transfer therapeutic genes in human pituitary adenomas.
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PMID:Lentiviral vectors efficiently transduce human gonadotroph and somatotroph adenomas in vitro. Targeted expression of transgene by pituitary hormone promoters. 1552 89

Endothelial cells (ECs) in normal vessels are poorly transducible by retroviral vectors, which require cell division for gene transduction. Among retroviruses, lentiviruses have the unique ability to integrate their genome into the chromatin of nondividing cells. Here we show that multiply attenuated, self-inactivating, lentiviral vectors transduce both proliferating and growth-arrested human umbilical vein ECs (HUVECs), human coronary artery ECs (HCAECs), and human coronary artery smooth muscle cells (HCASMCs), with high efficacy. Lentiviral vectors containing the enhanced green fluorescence protein (EGFP) transgene driven by either the cytomegalovirus or the elongation factor-1alpha promoter, but not the phosphoglycerate kinase promoter, directed high-level EGFP expression in endothelial and smooth muscle cells. The endothelium-specific Tie2 promoter also directed transgene expression in ECs. Re-insertion of cis-acting sequences from pol of human immunodeficiency virus type 1 (HIV-1) into the vectors improved transgene expression. A lentiviral vector containing the vascular endothelial growth factor transgene promoted EC proliferation and sprouting in vitro. In vivo gene transfer was studied by lumenal infusion of vector containing solutions into rat carotid arteries. Lentivirus-mediated EGFP gene transfer was observed in approximately 5% of ECs. Lentiviral vectors containing the LacZ transgene achieved detectable beta-galactosidase activity in rat arteries, albeit at a lower level compared with adenoviral vectors. This difference was mainly due to the lower concentration of lentiviral vector preparations. Lentivirus-mediated gene transfer was associated with minimal neointimal hyperplasia and scant inflammatory cell infiltrates in the media and adventitia. These observations indicate that lentiviral vectors may be useful for genetic modifications of vascular cells in vitro and in vivo.
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PMID:Multiply attenuated, self-inactivating lentiviral vectors efficiently transduce human coronary artery cells in vitro and rat arteries in vivo. 1569 40

Composite promoters combining the prostate-specific antigen (PSA) enhancer core element with promoter elements derived from gene coding for human prostate-specific transglutaminase gene, prostate-specific membrane antigen gene, prostate-specific antigen, rat probasin or phosphoglycerate kinase were characterized for their ability to specifically express the enhanced green fluorescent protein (EGFP) gene in prostate versus non-prostate cancer cell lines when transferred with a human immunodeficiency virus-1-based lentiviral vector. By themselves minimal proximal promoter elements were found to inefficiently promote relevant tissue-specific expression; in all the vectors tested, addition of the PSA enhancer core element markedly improved EGFP expression in LnCaP, a cancer prostate cell line used as a model for prostate cancer. The composite promoter was inactive in HuH7, a hepatocarcinoma cell line used as a model of neighboring non-prostate cancer cells. Among the promoters tested, the combination of the PSA enhancer and the rat probasin promoter showed both high specificity and a strong EGFP expression. Neither a high viral input nor the presence of the cPPT/CTS sequence affected composite promoter behavior. Our data suggest that composite prostate-specific promoters constructed by combining key elements from various promoters can improve and/or confer tissue specific expression in a lentiviral vector context.
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PMID:Use of the PSA enhancer core element to modulate the expression of prostate- and non-prostate-specific basal promoters in a lentiviral vector context. 1674 21

CD8(+) T lymphocytes control human immunodeficiency virus type 1 (HIV-1) infection by a cytotoxic major histocompatibility complex-restricted pathway as well as by secretion of noncytotoxic soluble inhibitory factors. Several components of CD8(+) cell supernatants have been identified that contribute to the latter activity. In this study we report that prothymosin alpha (ProTalpha), a protein found in the cell culture medium of the herpesvirus saimiri-transformed CD8(+) T-cell line, K#1 50K, has potent HIV-1-inhibitory activity. Depletion of native ProTalpha from an HIV-1-inhibitory fraction of CD8(+) cell supernatants removes the inhibitory activity, supporting its role in inhibition via soluble mediators. ProTalpha is an abundant, acidic peptide that has been reported to be localized in the nucleus and associated with cell proliferation and activation of transcription. In this report we demonstrate that ProTalpha suppresses HIV-1 replication, its activity is target cell specific, and inhibition occurs following viral integration. Native and recombinant ProTalpha protein potently inhibit HIV-1 long terminal repeat (LTR)-driven gene expression in macrophages. Furthermore studies using different promoters in lentiviral vectors (cytomegalovirus and phosphoglycerate kinase) revealed that suppression of viral replication by ProTalpha is not HIV LTR specific.
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PMID:Novel function of prothymosin alpha as a potent inhibitor of human immunodeficiency virus type 1 gene expression in primary macrophages. 1694 May 31

Artemis gene mutations are responsible for the development of a severe combined immunodeficiency [radiation-sensitive (RS) SCID] characterized by a severe B and T cell deficiency and a normal natural killer cell population. To establish the feasibility of a gene therapy approach to the treatment of RS-SCID, we generated a series of lentiviral vectors expressing human Artemis from different promoters and used them to transduce highly purified hematopoietic stem cells (HSCs) from Artemis knockout mice. HSCs transduced by the different viruses were transplanted into either lethally irradiated Rag-1-deficient animals or Artemis knockout mice treated with a nonmyeloablative dose of Busulfan. In both models, transplantation of HSCs transduced by a vector that used a murine phosphoglycerate kinase (PGK) promoter led to a complete functional correction of the immunodeficiency. Corrected animals displayed rescue of mature B cells with normal levels of serum immunoglobulins, together with complete rescue of the T cell compartment as evidenced by the presence of mature T lymphocytes in peripheral blood as well as normal values of thymocytes in thymus. Those B and T cells were capable of activation, as shown both by in vitro stimulation responses and in vivo after immune challenge. Overall, the results indicate that a gene therapy approach for RS-SCID involving the transplantation of genetically modified HSCs is indeed feasible. Furthermore, our studies suggest the possibility that nonmyeloablative conditioning regimens might be effectively used to promote engraftment of genetically modified cells in the case of diseases where standard irradiation-based myeloablative bone marrow transplantation protocols may prove problematic.
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PMID:Complete correction of murine Artemis immunodeficiency by lentiviral vector-mediated gene transfer. 1706 50

A simple, quantitative assay for measuring the oncogenic potential of integrating vectors is needed in order to improve vector design and safety. In this study, we have developed a transient plasmid-based assay to measure the activation of a reporter gene by an adjacent vector provirus. Plasmid pACT contains a luciferase cassette driven by a minimal, enhancerless promoter, into which vector proviruses are inserted upstream for evaluation by luciferase assays and northern blots. In a comparison of analogous vectors based on murine leukemia virus (MLV), human immunodeficiency virus (HIV), and foamy virus (FV), we observed significant enhancer activity and read-through transcription from MLV proviruses, and significant read-through transcription from HIV proviruses. HIV and FV proviruses containing an internal MLV long-terminal repeat (LTR) promoter also had significant enhancer activity, which was not observed with an internal promoter from the murine phosphoglycerate kinase-1 gene, PGK. These results demonstrate that neighboring gene activation can be limited by using internal promoter(s) lacking enhancer activity, especially when present in an FV vector backbone that prevents read-through transcription. Although the pACT assay does not measure oncogenesis directly, it should be useful for screening vectors before more time-consuming and costly animal studies are undertaken.
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PMID:A rapid and quantitative assay for measuring neighboring gene activation by vector proviruses. 1820 33

The development of leukemia as a consequence of vector-mediated genotoxicity in gene therapy trials for X-linked severe combined immunodeficiency (SCID-X1) has prompted substantial research effort into the design and safety testing of integrating vectors. An important element of vector design is the selection and evaluation of promoter-enhancer elements with sufficient strength to drive reliable immune reconstitution, but minimal propensity for enhancer-mediated insertional mutagenesis. In this study, we set out to explore the effect of promoter-enhancer selection on the efficacy and safety of human immunodeficiency virus-1-derived lentiviral vectors in gammac-deficient mice. We observed incomplete or absent T- and B-cell development in mice transplanted with progenitors expressing gammac from the phosphoglycerate kinase (PGK) and Wiscott-Aldrich syndrome (WAS) promoters, respectively. In contrast, functional T- and B-cell compartments were restored in mice receiving an equivalent vector containing the elongation factor-1-alpha (EF1alpha) promoter; however, 4 of 14 mice reconstituted with this vector subsequently developed lymphoma. Extensive analyses failed to implicate insertional mutagenesis or gammac overexpression as the underlying mechanism. These findings highlight the need for detailed mechanistic analysis of tumor readouts in preclinical animal models assessing vector safety, and suggest the existence of other ill-defined risk factors for oncogenesis, including replicative stress, in gene therapy protocols targeting the hematopoietic compartment.
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PMID:Lymphomagenesis in SCID-X1 mice following lentivirus-mediated phenotype correction independent of insertional mutagenesis and gammac overexpression. 2043 93


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