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Dharmapuri S, Peruzzi D, Marra E, Palombo F, Bett AJ, Bartz SR, Yong M, Ciliberto G, La Monica N, Buser CA, Toniatti C, Aurisicchio L. Intratumor RNA interference of cell cycle genes slows down tumor progression. Gene Ther 2011; 18:727-33. [PMID: 21390070 DOI: 10.1038/gt.2011.27] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Small interfering RNAs (siRNAs) are emerging as promising therapeutic tools. However, the widespread clinical application of such molecules as modulators of gene expression is still dependent on several aspects that limit their bioavailability. One of the most promising strategies to overcome the barriers faced by gene silencing molecules involves the use of lipid-based nanoparticles (LNPs) and viral vectors, such as adenoviruses (Ads). The primary obstacle for translating gene silencing technology from an effective research tool into a feasible therapeutic strategy remains its efficient delivery to the targeted cell type in vivo. In this study, we tested the capability of LNPs and Ad to transduce and treat locally tumors in vivo. Efficient knockdown of a surrogate reporter (luciferase) and therapeutic target genes such as the kinesin spindle protein (KIF11) and polo-like kinase 1 were observed. Most importantly, this activity led to a cell cycle block as a consequence and slowed down tumor progression in tumor-bearing animals. Our data indicate that it is possible to achieve tumor transduction with si/short hairpin RNAs and further improve the delivery strategy that likely in the future will lead to the ideal non-viral particle for targeted cancer gene silencing.
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Affiliation(s)
- S Dharmapuri
- Merck Research Laboratories, IRBM P Angeletti, Pomezia (Rome), Italy
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2
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Abstract
Cyclosporin A (CsA) is a potent inhibitor of the NFAT family of transcription factors that enhance T cell activation. The observation that human immunodeficiency virus type 1 (HIV-1)-positive transplant recipients have a reduced HIV-1 viral burden during treatment with CsA suggested that NFAT may play a direct role in enhancing transcription of the HIV-1 viral genome. Two sets of NFAT binding sites were identified in the HIV-1 long terminal repeat (LTR) promoter by in vitro footprinting with full-length recombinant NFAT protein, and gel shift analysis of nuclear protein from polyclonally activated primary CD4 T cells revealed specific binding of NFAT1 to the NFkappaB binding sites of the HIV-1 LTR. Activation of primary CD4 T cells transiently transfected with a HIV-1 LTR luciferase reporter plasmid, lacking the NFAT binding sites in the upstream putative negative regulatory element but maintaining the NFkappaB/NFAT sites, demonstrated increased HIV-1 gene expression when cotransfected with a NFAT1 expression vector. Moreover, CsA, FK506, and a dominant-negative NFAT1 protein independently inhibited HIV-1 LTR promoter activity in CD4 T cells stimulated with phorbol ester and calcium ionophore. In primary human CD4 T cells, CsA also inhibited promoter activity directed by multimers of binding sites for NFAT, while having no effect on NFkappaB multimer-driven promoter activity. Increasing NFAT1 levels in CD4 T cells transiently transfected with a HIV-1 provirus also increased p24 protein expression. Thus, NFAT may be a target for prevention of HIV-1 LTR-directed gene expression in human CD4 T cells.
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Affiliation(s)
- R Q Cron
- Division of Immunology and Transplantation Biology, Stanford University Medical Center, Palo Alto, California 94304-5208, USA
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Bartz SR, Emerman M. Human immunodeficiency virus type 1 Tat induces apoptosis and increases sensitivity to apoptotic signals by up-regulating FLICE/caspase-8. J Virol 1999; 73:1956-63. [PMID: 9971775 PMCID: PMC104437 DOI: 10.1128/jvi.73.3.1956-1963.1999] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Apoptosis contributes to the loss of CD4 cells during human immunodeficiency virus type 1 (HIV-1) infection. Although the product of the env gene, gp160/gp120, is known to play a role in cell death mediated by HIV-1, the role of other HIV-1 genes in the process is unclear. We found that HIV-1 lacking the env gene (HIVDeltaenv) still induced apoptosis in T-cell lines and primary CD4 T cells. The ability to induce apoptosis was attributable to Tat, a viral regulatory protein. Tat induction of apoptosis was separate from the transactivation function of Tat, required expression of the second exon of Tat, and was associated with the increased expression and activity of caspase-8 (casp-8), a signaling molecule in apoptotic pathways. Moreover, induction of apoptosis could be prevented by treating cells with an inhibitor of casp-8. In addition, we show that HIV-1Deltaenv infection and Tat expression increased the sensitivity of cells to Fas-mediated apoptosis, an apoptotic pathway that signals via casp-8. The up-regulation of casp-8 by HIV-1 Tat expression may contribute to the increased apoptosis and sensitivity to apoptotic signals observed in the cells of HIV-1-infected persons.
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Affiliation(s)
- S R Bartz
- Divisions of Molecular Medicine and Basic Science, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
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Abstract
We describe a method for the production of high-titer stocks of human immunodeficiency virus type 1 (HIV-1) pseudotyped with vesicular stomatitis virus envelope glycoprotein (VSV G). VSV G pseudotypes provide several advantages over other retroviral envelope proteins. The VSV G envelope is mechanically stable, enabling ultracentrifugal concentration of virions to high titers, and VSV G has a broad host range, enabling infection of many mammalian and nonmammalian cell types. VSV G pseudotypes of HIV-1 are useful for the study of HIV infection and replication kinetics and for the study of the function of specific viral proteins. We describe applications for the study of HIV-1 using VSV G pseudotypes. Additionally, we describe a method for pseudotyping retroviral vectors with VSV G. The same advantages of VSV G pseudotypes of HIV-1 apply to retroviral vectors; VSV G pseudotyped retroviral vectors may be used to introduce genes of interest into a wide variety of cell lines.
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Affiliation(s)
- S R Bartz
- Division of Molecular Medicine, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
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Vodicka MA, Goh WC, Wu LI, Rogel ME, Bartz SR, Schweickart VL, Raport CJ, Emerman M. Indicator cell lines for detection of primary strains of human and simian immunodeficiency viruses. Virology 1997; 233:193-8. [PMID: 9201229 DOI: 10.1006/viro.1997.8606] [Citation(s) in RCA: 178] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CCR5 and CXCR4 are the two major coreceptors that have been identified for human immunodeficiency virus (HIV) entry. We have modified several beta-galactosidase-based HIV indicator cell lines to express CCR5 and/or CXCR4. Using these new reagents, we have been able to detect all primary isolates tested using one or both of these cell lines. However, there is large variation in the absolute viral infectivity among primary strains. Furthermore, all HIV strains are capable of causing syncytia in the indicator cells when the coreceptor is present regardless of whether they had previously been characterized as "syncytia-inducing" or "non-syncytium-inducing."
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Affiliation(s)
- M A Vodicka
- Division of Molecular Medicine, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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Bartz SR, Rogel ME, Emerman M. Human immunodeficiency virus type 1 cell cycle control: Vpr is cytostatic and mediates G2 accumulation by a mechanism which differs from DNA damage checkpoint control. J Virol 1996; 70:2324-31. [PMID: 8642659 PMCID: PMC190074 DOI: 10.1128/jvi.70.4.2324-2331.1996] [Citation(s) in RCA: 215] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Vpr is a 96-amino-acid protein encoded by human immunodeficiency virus type 1 (HIV-1) that prevents proliferation of infected cells. We have established a system for infection of 100% of a T-cell population with HIV and use this system to show that within the context of HIV-1 infection, Vpr is primarily cytostatic rather than cytotoxic. Vpr acts upstream of dephosphorylation of the mitotic cyclin-dependent kinase, and causes infected cells to accumulate in the G2 stage of the cell cycle. However, some HIV-1 infected cells increase in ploidy and size, accumulating DNA to an 8N level. Furthermore, the mechanism of the Vpr mitotic block is qualitatively different from that of G2 DNA damage checkpoint control.
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Affiliation(s)
- S R Bartz
- Division of Molecular Medicine, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA
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Abstract
Natural immunity may be involved in controlling viral spread in hosts infected with HIV. A panel of gamma delta T cell receptor-positive lymphocyte clones was isolated from the peripheral blood of healthy HIV- donors and tested for anti-HIV cytotoxic responses. Twelve of 30 (40%) V gamma 9+/V delta 2+ T cell clones, but none of seven V delta 1+ T cell clones, displayed lytic activity against HIV-infected cells. The V gamma 9+/V delta 2+ clones cytotoxic for HIV-infected cells also lysed Daudi cells. However, not all V gamma 9+/V delta 2+ clones which lysed Daudi targets had the capacity to lyse HIV-infected cells. Some of the gamma delta T cell clones were also investigated for potential proliferative responses to HIV-infected cells. One V gamma 9+/V delta 2+ T cell clone (ME8-7) and one V delta 1+ T cell clone (ME18-2) demonstrated proliferative responses towards HIV-infected cells. Another V gamma 9+/V delta 2+ clone (VM39) proliferated in response to cell-free HIV. Taken together, these results provide direct evidence of anti-HIV gamma delta T cell responses in healthy, HIV- persons.
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Affiliation(s)
- M Wallace
- Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison, USA
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Bartz SR, Hohenwalter E, Hu MK, Rich DH, Malkovsky M. Inhibition of human immunodeficiency virus replication by nonimmunosuppressive analogs of cyclosporin A. Proc Natl Acad Sci U S A 1995; 92:5381-5. [PMID: 7777516 PMCID: PMC41698 DOI: 10.1073/pnas.92.12.5381] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Analogs of the immunosuppressive cyclic undecapeptide cyclosporin A (CsA) with substitutions in positions 1, 4, 6, and/or 11 were rationally designed to possess substantially diminished or no immunosuppressive activity. When these compounds were assayed for their capacity to interfere with the replication of human immunodeficiency virus, some displayed a potent antiviral activity in newly infected cells. However, only CsA could interfere with virus replication in persistently infected cells. One CsA analog with antiviral activity costimulated the phytohemagglutinin-induced production of interleukin 2 by human lymphocytes. Human immunodeficiency virus particles from drug-exposed cells showed lower infectivity than virions from untreated cells. Thus, these nonimmunosuppressive analogs of CsA constitute a promising class of lead compounds to develop drugs for effective treatment of the acquired immunodeficiency syndrome.
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Affiliation(s)
- S R Bartz
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison 53706, USA
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Abstract
The possible physical association of heat shock proteins (Hsp's) with immunodeficiency viruses (HIV and SIV) has been examined. The virions were purified by a) polyethylene glycol (PEG) precipitation and Sepharose 4B filtration, b) PEG precipitation and centrifugation over a Renografin gradient, or c) PEG precipitation and Matrex Cellufine Sulfate affinity chromatography. Western blotting revealed an Hsp60 related protein associated with HIV and SIV. Other Hsp's (such as Hsp70) were not detected, suggesting a specific interaction between Hsp60 and viral factors.
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Affiliation(s)
- S R Bartz
- Dept. of Medical Microbiology and Immunology, Univ. of Wisconsin, Madison 53706
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Malkovsky M, Bartz SR, MacKenzie D, Radtke BE, Wallace M, Manning J, Pauza CD, Fisch P. Are gamma delta T cells important for the elimination of virus-infected cells? J Med Primatol 1992; 21:113-8. [PMID: 1433261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Rhesus monkeys (Macaca mulatta) gamma delta T cells were identified using a monoclonal antibody. The relative representation of gamma delta T lymphocytes in the peripheral blood, lymph nodes, and spleen resembles that of Homo sapiens. The analysis of function and specificity revealed further significant similarities between the simian and human gamma delta T-cell systems. Since both human and monkey gamma delta T lymphocytes can effectively lyse cells infected with immunodeficiency viruses, it is possible that the primate gamma delta T-cell systems contribute to antiviral immunosurveillance.
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Affiliation(s)
- M Malkovsky
- Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison 53706
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