A hairpin ribozyme inhibits expression of diverse strains of human immunodeficiency virus type 1.

Yu, Meichen; Ojwang, Joshua O.; Yamada, Osamu; Hampel, Arnold; Rapapport, Jay; Looney, David J.; Wong‐Staal, Flossie

doi:10.1073/pnas.90.13.6340

Cited by 211 publications

(109 citation statements)

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“…Cleavage time-course experiments (see Materials and methods) with each agents in vivo will depend on their ability to function in a complex cellular environment. To that end, ribozyme ribozyme indicated that in both cases the addition of a genes encoding BR1 and BR3, their tetraloop variants (BR1-TL and BR3-TL) and their disabled counterparts (dBR1 and dBR3) were cloned into a retroviral vector pLNT, as one of the possible gene therapy delivery vehicles, under the control of the human tRNA val pol III promoter 17,18 (see Figure 1a). This retroviral vector was chosen due to its successful application in delivering ribozymes against HIV.…”

Section: Resultsmentioning

confidence: 99%

Intracellular application of hairpin ribozyme genes against hepatitis B virus

Welch¹,

Tritz²,

Yei³

et al. 1997

Gene Ther

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HBV, a partially double-stranded DNA virus, replicates modifications were performed on these two Rzs, with the through a pregenomic RNA (pgRNA) intermediate, which goal of increasing catalytic efficiency both in vitro and in provides a therapeutic opportunity for a novel antiviral gene cells. To determine the Rz activities in liver cells, the therapy based on ribozyme RNA cleavage. Three hairpin cDNAs for each of the anti-HBV Rzs (and their catalytically ribozymes (Rzs) were designed which have the potential disabled negative controls) were cloned into retroviral vecto disrupt HBV replication by targeting the pgRNA as well tors. Unmodified ribozymes co-expressed with HBV in as specific mRNAs encoding the HBV surface antigen human liver Huh7 cells reduced the level of viral particle (HBsAg), the polymerase and the X protein. The ability of production by up to 66% based on the endogenous polyeach ribozyme to cleave approximately 0.3 kb HBV merase assay, while the structurally modified ribozymes subgenomic RNA fragments was tested in vitro. Two of the inhibited HBV production up to 83%. These encouraging three Rzs tested (BR1 and BR3) were capable of cleaving results indicate the feasibility of ribozyme-mediated gene their respective RNA substrates, while their catalytically therapy for the treatment of HBV infections. disabled mutated counterpart Rzs were not. Structural Keywords: plasmid-independent transcription; endogenous polymerase assay; ribozyme kinetics; RNA cleavage; antiviral problems associated with the direct injection of antisense Introduction DNA. Stable expression of the anti-HBV ribozymes in Hepatitis B is a major worldwide health problem.liver cells could theoretically lead to lifelong intracellular Although a vaccine is currently available for hepatitis B immunity against HBV. virus (HBV), it is estimated that no less than two billion HBV undergoes replication through reverse transcrippeople are infected globally and 300 million are chrontion of a pregenomic RNA intermediate 5,6 and is thus ically infected carriers. 1,2 Approximately 10% of infected somewhat analogous to HIV and other retroviruses. This adults will develop a chronic, life-long infection often offers an excellent rationale for the use of ribozymes as with devastating consequences. 1,2 About 2 million deaths antiviral agents for HBV based on the successful preclinioccur each year as a direct result of chronic HBV infection cal studies of ribozymes against HIV infections (for due to either cirrhosis or primary liver cancer. Presently review see Refs 7 and 8). An anti-HBV ribozyme can the only partially effective treatment for hepatitis B is potentially be multifunctional, targeting both the pregeninterferon-␣, which is effective in only less than half of omic RNA as well as the viral mRNAs (see Figure 1a). all patients.In addition, by targeting the ribozymes to small highly One recently investigated approach to the treatment of conserved regions of the viral genome, the possibility of HBV infection has been the utilization of antise...

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Section: Resultsmentioning

confidence: 99%

Intracellular application of hairpin ribozyme genes against hepatitis B virus

Welch¹,

Tritz²,

Yei³

et al. 1997

Gene Ther

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“…[19][20][21][22] There are very few reports that demonstrated adequate inhibition of an endogenous cellular transcript -especially one expressed at high levels, and especially in a mixed population of transduced cells. 10,15 Two recent reports show the effectiveness of ribozymes in inhibiting the expression of the transgene in transgenic mice. 23,24 The common thread in most of these reports is the necessity for ribozymes to be expressed at high levels in order to inhibit the target gene expression.…”

Section: Discussionmentioning

confidence: 99%

“…[10][11][12][13][14][15] Ribozymes have an advantage in the therapy of chronic disease since they are not degraded when the target RNA is cleaved, and therefore, theoretically they need not be produced at higher levels than the target transcript. By using a hammerhead ribozyme, we should be able to target the mutant form of ␣1AT mRNA by using ␣1AT guide sequences attached to the ribozyme catalytic core sequence.…”

Section: Introductionmentioning

confidence: 99%

A novel SV40-based vector successfully transduces and expresses an alpha 1-antitrypsin ribozyme in a human hepatoma-derived cell line

et al. 1999

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Alpha 1-antitrypsin (␣1AT) deficiency disease is one of the ribozyme cleavage. Ribozymes were effective in inhibiting more common hereditary disorders that affects the liver ␣1AT expression in a human hepatoma cell line using a and lung. The liver disease of ␣1AT deficiency is generally newly developed simian virus (SV40) vector system. In thought to be caused by the accumulation of an abnormal addition, the hepatoma cell line was stably transduced with ␣1AT protein in hepatocytes, whereas the lung disease is a modified ␣1AT cDNA that was capable of producing wildthought to be due to a relative lack of the normal protein type ␣1AT protein, but was not cleaved by the ribozyme in the circulation. Therefore, one possible approach to prethat decreased endogenous ␣1AT expression. These vent and treat ␣1AT disease is to both inhibit the results suggest that ribozymes can be employed for the expression of the mutated ␣1AT gene, and to provide a specific inhibition for an abnormal ␣1AT gene product, the means of synthesizing the normal protein. To do this, we first step in designing a gene therapy for the disease. The designed specific hammerhead ribozymes that were capfindings also suggest that the novel SV40-derived vector able of cleaving the ␣1AT mRNA at specific sites, and conmay represent a fundamental improvement in the gene structed a modified ␣1AT cDNA not susceptible to therapeutic armarmentarium.

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“…Since conventional antiretroviral medications, such as zidovudine, are only partially effective, more effective therapy will be necessary. Recently, transfection of mature T cells and SC with mutant transdominant HIV genes has been proposed as an alternative modality to resist active HIV infection [42][43][44]. Based on the results of our studies, transfection of SCs with transdominant HIV genes in conjunction with cultured thymic epithelial transplantations would appear to be the next step in order to protect the thymocyte and monocyte lineages, as well as the thymic microenvironment in order to immune reconstitute patients with AIDS.…”

Section: Fig 4 Cd34 + Scs Were Labeled With Cmtmr and Then Coculturmentioning

confidence: 82%

T Cell Differentiation/Maturation of CD34⁺Stem Cells from HIV‐Seropositive Hemophiliacs in Cultured Thymic Epithelial Fragments

et al. 1996

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In summary, these studies demonstrated that HIV-infected hemophiliac bone marrowderived nonadherent CD34 + SC were capable of differentiating and/or maturing into T cells when cocultured in a normal allogeneic thymic environment. Furthermore, the T cells derived from derived CD34 + SC were capable of differentiating into T cells when cocultured in a normal allogeneic thymic environment, proliferated maximally with APCs from the stem cell donor and were tolerant of thymic HLA class II antigens, and to a lesser degree to stem cell donor B cell HLA antigens.

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A hairpin ribozyme inhibits expression of diverse strains of human immunodeficiency virus type 1.

Abstract: Ribozymes have enormous potential as antiviral agents. We have previously reported that a hairpin ribozyme expressed under the control of the 3-actin promoter that cleaves human Immunodeficiency virus type 1 (HIV-1)

Cited by 211 publications

References 16 publications

Intracellular application of hairpin ribozyme genes against hepatitis B virus

Intracellular application of hairpin ribozyme genes against hepatitis B virus

A novel SV40-based vector successfully transduces and expresses an alpha 1-antitrypsin ribozyme in a human hepatoma-derived cell line

T Cell Differentiation/Maturation of CD34⁺Stem Cells from HIV‐Seropositive Hemophiliacs in Cultured Thymic Epithelial Fragments

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A hairpin ribozyme inhibits expression of diverse strains of human immunodeficiency virus type 1.

Abstract: Ribozymes have enormous potential as antiviral agents. We have previously reported that a hairpin ribozyme expressed under the control of the 3-actin promoter that cleaves human Immunodeficiency virus type 1 (HIV-1)

Cited by 211 publications

References 16 publications

Intracellular application of hairpin ribozyme genes against hepatitis B virus

Intracellular application of hairpin ribozyme genes against hepatitis B virus

A novel SV40-based vector successfully transduces and expresses an alpha 1-antitrypsin ribozyme in a human hepatoma-derived cell line

T Cell Differentiation/Maturation of CD34+Stem Cells from HIV‐Seropositive Hemophiliacs in Cultured Thymic Epithelial Fragments

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T Cell Differentiation/Maturation of CD34⁺Stem Cells from HIV‐Seropositive Hemophiliacs in Cultured Thymic Epithelial Fragments