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Wong B, Birtch R, Rezaei R, Jamieson T, Crupi MJF, Diallo JS, Ilkow CS. Optimal delivery of RNA interference by viral vectors for cancer therapy. Mol Ther 2023; 31:3127-3145. [PMID: 37735876 PMCID: PMC10638062 DOI: 10.1016/j.ymthe.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/28/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
In recent years, there has been a surge in the innovative modification and application of the viral vector-based gene therapy field. Significant and consistent improvements in the engineering, delivery, and safety of viral vectors have set the stage for their application as RNA interference (RNAi) delivery tools. Viral vector-based delivery of RNAi has made remarkable breakthroughs in the treatment of several debilitating diseases and disorders (e.g., neurological diseases); however, their novelty has yet to be fully applied and utilized for the treatment of cancer. This review highlights the most promising and emerging viral vector delivery tools for RNAi therapeutics while discussing the variables limiting their success and suitability for cancer therapy. Specifically, we outline different integrating and non-integrating viral platforms used for gene delivery, currently employed RNAi targets for anti-cancer effect, and various strategies used to optimize the safety and efficacy of these RNAi therapeutics. Most importantly, we provide great insight into what challenges exist in their application as cancer therapeutics and how these challenges can be effectively navigated to advance the field.
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Affiliation(s)
- Boaz Wong
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Rayanna Birtch
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Reza Rezaei
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Taylor Jamieson
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mathieu J F Crupi
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jean-Simon Diallo
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Carolina S Ilkow
- Centre for Innovative Cancer Research, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
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Schaible P, Bethge W, Lengerke C, Haraszti RA. RNA Therapeutics for Improving CAR T-cell Safety and Efficacy. Cancer Res 2023; 83:354-362. [PMID: 36512627 PMCID: PMC7614194 DOI: 10.1158/0008-5472.can-22-2155] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/02/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022]
Abstract
Autologous chimeric antigen receptor (CAR) T cells have recently emerged as potent tools in the fight against cancer, with promising therapeutic efficacy against hematological malignancies. However, several limitations hamper their widespread clinical use, including availability of target antigen, severe toxic effects, primary and secondary resistance, heterogeneous quality of autologous T cells, variable persistence, and low activity against solid tumors. Development of allogeneic off-the-shelf CAR T cells could help address some of these limitations but is impeded by alloimmunity with either rejection and limited expansion of allo-CAR T cells or CAR T cells versus host reactions. RNA therapeutics, such as small interfering RNAs, microRNAs, and antisense oligonucleotides, are able to silence transcripts in a sequence-specific and proliferation-sensitive way, which may offer a way to overcome some of the challenges facing CAR T-cell development and clinical utility. Here, we review how different RNA therapeutics or a combination of RNA therapeutics and genetic engineering could be harnessed to improve the safety and efficacy of autologous and allogeneic CAR T-cell therapy.
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Affiliation(s)
- Philipp Schaible
- Department of Internal Medicine II, Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
| | - Wolfgang Bethge
- Department of Internal Medicine II, Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
| | - Claudia Lengerke
- Department of Internal Medicine II, Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
| | - Reka Agnes Haraszti
- Department of Internal Medicine II, Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
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Chen MJ, Gatignol A, Scarborough RJ. The discovery and development of RNA-based therapies for treatment of HIV-1 infection. Expert Opin Drug Discov 2023; 18:163-179. [PMID: 36004505 DOI: 10.1080/17460441.2022.2117296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Long-term control of HIV-1 infection can potentially be achieved using autologous stem cell transplants with gene-modified cells. Non-coding RNAs represent a diverse class of therapeutic agents including ribozymes, RNA aptamers and decoys, small interfering RNAs, short hairpin RNAs, and U1 interference RNAs that can be designed to inhibit HIV-1 replication. They have been engineered for delivery as drugs to complement current HIV-1 therapies and as gene therapies for a potential HIV-1 functional cure. AREAS COVERED This review surveys the past three decades of development of these RNA technologies with a focus on their efficacy and safety for treating HIV-1 infections. We describe the mechanisms of each RNA-based agent, targets they have been developed against, efforts to enhance their stability and efficacy, and we evaluate their performance in past and ongoing preclinical and clinical trials. EXPERT OPINION RNA-based technologies are among the top candidates for gene therapies where they can be stably expressed for long-term suppression of HIV-1. Advances in both gene and drug delivery strategies and improvements to non-coding RNA stability and antiviral properties will cooperatively drive forward progress in improving drug therapy and engineering HIV-1 resistant cells.
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Affiliation(s)
- Michelle J Chen
- Lady Davis Institute for Medical Research, Montréal, Québec, Canada.,Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec, Canada
| | - Anne Gatignol
- Lady Davis Institute for Medical Research, Montréal, Québec, Canada.,Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec, Canada.,Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
| | - Robert J Scarborough
- Lady Davis Institute for Medical Research, Montréal, Québec, Canada.,Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
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Pai S, Mudgal J, Kamath BV, Pai KSR. An insight on promising strategies hoping to cure HIV-1 infection by targeting Rev protein-short review. Pharmacol Rep 2021; 73:1265-1272. [PMID: 33840054 PMCID: PMC8460518 DOI: 10.1007/s43440-021-00257-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 01/23/2023]
Abstract
Human immunodeficiency virus-1 (HIV-1) infection remains to be one of the major threats throughout the world. Many researchers are working in this area to find a cure for HIV-1. The group of the FDA approved drugs which are currently used against HIV-1 in the clinical practice include nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), integrase inhibitors (InIs), and protease inhibitors (PIs). Fixed dose combinations (FDCs) of these drugs are available and are used as per the anti-retroviral therapy (ART) guidelines. Despite these, unfortunately, there is no cure for HIV1 infection to date. The present review is focused upon describing the importance of a post-transcriptional regulatory protein "Rev", responsible for latent HIV-1 infection as a possible, and promising therapeutic target against HIV-1.
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Affiliation(s)
- Sahana Pai
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Jayesh Mudgal
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - B Venkatesh Kamath
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - K Sreedhara Ranganath Pai
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
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Abstract
As the HIV pandemic rapidly spread worldwide in the 1980s and 1990s, a new approach to treat cancer, genetic diseases, and infectious diseases was also emerging. Cell and gene therapy strategies are connected with human pathologies at a fundamental level, by delivering DNA and RNA molecules that could correct and/or ameliorate the underlying genetic factors of any illness. The history of HIV gene therapy is especially intriguing, in that the virus that was targeted was soon co-opted to become part of the targeting strategy. Today, HIV-based lentiviral vectors, along with many other gene delivery strategies, have been used to evaluate HIV cure approaches in cell culture, small and large animal models, and in patients. Here, we trace HIV cell and gene therapy from the earliest clinical trials, using genetically unmodified cell products from the patient or from matched donors, through current state-of-the-art strategies. These include engineering HIV-specific immunity in T-cells, gene editing approaches to render all blood cells in the body HIV-resistant, and most importantly, combination therapies that draw from both of these respective "offensive" and "defensive" approaches. It is widely agreed upon that combinatorial approaches are the most promising route to functional cure/remission of HIV infection. This chapter outlines cell and gene therapy strategies that are poised to play an essential role in eradicating HIV-infected cells in vivo.
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Tsukamoto T. Gene Therapy Approaches to Functional Cure and Protection of Hematopoietic Potential in HIV Infection. Pharmaceutics 2019; 11:pharmaceutics11030114. [PMID: 30862061 PMCID: PMC6470728 DOI: 10.3390/pharmaceutics11030114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 12/28/2022] Open
Abstract
Although current antiretroviral drug therapy can suppress the replication of human immunodeficiency virus (HIV), a lifelong prescription is necessary to avoid viral rebound. The problem of persistent and ineradicable viral reservoirs in HIV-infected people continues to be a global threat. In addition, some HIV-infected patients do not experience sufficient T-cell immune restoration despite being aviremic during treatment. This is likely due to altered hematopoietic potential. To achieve the global eradication of HIV disease, a cure is needed. To this end, tremendous efforts have been made in the field of anti-HIV gene therapy. This review will discuss the concepts of HIV cure and relative viral attenuation and provide an overview of various gene therapy approaches aimed at a complete or functional HIV cure and protection of hematopoietic functions.
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Affiliation(s)
- Tetsuo Tsukamoto
- Department of Immunology, Kindai University Faculty of Medicine, Osaka 5898511, Japan.
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Raja MAG, Katas H, Amjad MW. Design, mechanism, delivery and therapeutics of canonical and Dicer-substrate siRNA. Asian J Pharm Sci 2019; 14:497-510. [PMID: 32104477 PMCID: PMC7032099 DOI: 10.1016/j.ajps.2018.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 12/07/2018] [Accepted: 12/24/2018] [Indexed: 12/12/2022] Open
Abstract
Upon the discovery of RNA interference (RNAi), canonical small interfering RNA (siRNA) has been recognized to trigger sequence-specific gene silencing. Despite the benefits of siRNAs as potential new drugs, there are obstacles still to be overcome, including off-target effects and immune stimulation. More recently, Dicer substrate siRNA (DsiRNA) has been introduced as an alternative to siRNA. Similarly, it also is proving to be potent and target-specific, while rendering less immune stimulation. DsiRNA is 25–30 nucleotides in length, and is further cleaved and processed by the Dicer enzyme. As with siRNA, it is crucial to design and develop a stable, safe, and efficient system for the delivery of DsiRNA into the cytoplasm of targeted cells. Several polymeric nanoparticle systems have been well established to load DsiRNA for in vitro and in vivo delivery, thereby overcoming a major hurdle in the therapeutic uses of DsiRNA. The present review focuses on a comparison of siRNA and DsiRNA on the basis of their design, mechanism, in vitro and in vivo delivery, and therapeutics.
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Affiliation(s)
- Maria Abdul Ghafoor Raja
- Department of Pharmaceutics, Faculty of Pharmacy, Northern Border University, Rafha 73211, Saudi Arabia
| | - Haliza Katas
- Centre for Drug Delivery Research, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia
| | - Muhammad Wahab Amjad
- Department of Pharmaceutics, Faculty of Pharmacy, Northern Border University, Rafha 73211, Saudi Arabia
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8
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Abstract
Short interfering RNAs (siRNAs) are as effective at targeting and silencing genes by RNA interference (RNAi) as long double-stranded RNAs (dsRNAs). siRNAs are widely used for assessing gene function in cultured mammalian cells or early developing vertebrate embryos. siRNAs are also promising reagents for developing gene-specific therapeutics. Specifically, the inhibition of HIV-1 replication is particularly well-suited to RNAi, as several stages of the viral life cycle and many viral and cellular genes can be targeted. The future success of this approach will depend on recent advances in siRNA-based silencing technologies.
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Affiliation(s)
- Hiroshi Takaku
- Department of Life & Environmental Sciences and High Technology Research Center, Chiba Institute of Technology, Chiba, Japan.
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Farazmandfar T, Haghshenas MR, Shahbazi M. Inhibition of HIV-1 by a Lentiviral Vector with a Novel Tat-Inducible Expression System and a Specific Tropism to the Target Cells. Hum Gene Ther 2015; 26:680-7. [PMID: 26077977 PMCID: PMC4630793 DOI: 10.1089/hum.2015.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/04/2015] [Indexed: 12/15/2022] Open
Abstract
Today, lentiviral vectors are favorable vectors for RNA interference delivery in anti-HIV therapeutic approaches. Nevertheless, problems such as the specific recognition of target cells and uncontrolled expression of the transgene can restrict their use in vivo. Herein we present a new HIV-inducible promoter to express anti-HIV short hairpin RNA (shRNA) by RNA Pol II in mammalian cells. We likewise showed a novel third-generation lentiviral vector system with more safety and a specific tropism to the target cells. The new promoter, CkRhsp, was constructed from the chicken β-actin core promoter with the R region of HIV-1 long terminal repeat fused upstream of minimal hsp70 promoter. This system was induced by HIV-1 Tat, and activates transcription of two shRNAs against two conserved regions of HIV-1 transcripts produced in two steps of the virus life cycle. We also mimicked HIV-1 cell tropism by using the HIV-1 envelope in structure of third-generation lentiviral vector. The new fusion promoter efficiently expressed shRNA in a Tat-inducible manner. HIV-1 replication was inhibited in transient transfection and stable transduction assays. The new viral vector infected only CD4+cells. CkRhsp promoter may be safer than other inducible promoters for shRNA-mediated gene therapies against HIV. The use of the wild envelope in the vector packaging system may provide the specific targeting T lymphocytes and hematopoietic stem cells for anti-HIV-1 therapeutic approaches in vivo.
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Affiliation(s)
- Touraj Farazmandfar
- Department of Molecular Medicine, Faculty of Advanced Medical Technologies, Golestan University of Medical Sciences, Gorgan, Iran
- Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Reza Haghshenas
- Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Majid Shahbazi
- Department of Molecular Medicine, Faculty of Advanced Medical Technologies, Golestan University of Medical Sciences, Gorgan, Iran
- Medical Cellular & Molecular Research Center, Taleghani Children Hospital of Golestan University of Medical Sciences, Gorgan, Iran
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Bennett MS, Akkina R. Gene therapy strategies for HIV/AIDS: preclinical modeling in humanized mice. Viruses 2013; 5:3119-41. [PMID: 24351796 PMCID: PMC3967164 DOI: 10.3390/v5123119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/04/2013] [Accepted: 12/03/2013] [Indexed: 12/28/2022] Open
Abstract
In the absence of an effective vaccine and lack of a complete cure, gene therapy approaches to control HIV infection offer feasible alternatives. Due to the chronic nature of infection, a wide window of opportunity exists to gene modify the HIV susceptible cells that continuously arise from the bone marrow source. To evaluate promising gene therapy approaches that employ various anti-HIV therapeutic molecules, an ideal animal model is necessary to generate important efficacy and preclinical data. In this regard, the humanized mouse models that harbor human hematopoietic cells susceptible to HIV infection provide a suitable in vivo system. This review summarizes the currently used humanized mouse models and different anti-HIV molecules utilized for conferring HIV resistance. Humanized mouse models are compared for their utility in this context and provide perspectives for new directions.
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Affiliation(s)
| | - Ramesh Akkina
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1619 Campus delivery, Fort Collins, CO 80523, USA.
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RNA interference--a silent but an efficient therapeutic tool. Appl Biochem Biotechnol 2013; 169:1774-89. [PMID: 23340870 DOI: 10.1007/s12010-013-0098-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/10/2013] [Indexed: 12/12/2022]
Abstract
RNA interference (RNAi) is an evolutionary conserved gene regulation pathway that has emerged as an important discovery in the field of molecular biology. One of the important advantages of RNAi in therapy is that it brings about efficient downregulation of gene expression by targeting complementary transcripts in comparison with other antisense-based techniques. RNAi can be can be achieved by introducing chemically synthesized small interfering RNAs (siRNAs) into a cell system. A more stable knockdown effect can be brought about by the use of plasmid or viral vectors encoding the siRNA. RNAi has been used in reverse genetics to understand the function of specific genes and also as a therapeutic tool in treating human diseases. This review provides a brief insight into the therapeutic applications of RNAi against debilitating diseases.
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12
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Yang S, Chen Y, Ahmadie R, Ho EA. Advancements in the field of intravaginal siRNA delivery. J Control Release 2013; 167:29-39. [PMID: 23298612 DOI: 10.1016/j.jconrel.2012.12.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/14/2012] [Accepted: 12/17/2012] [Indexed: 12/17/2022]
Abstract
The vaginal tract is a suitable site for the administration of both local and systemic acting drugs. There are numerous vaginal products on the market such as those approved for contraception, treatment of yeast infection, hormonal replacement therapy, and feminine hygiene. Despite the potential in drug delivery, the vagina is a complex and dynamic organ that requires greater understanding. The recent discovery that injections of double stranded RNA (dsRNA) in Caenorhabditis elegans (C. elegans) results in potent gene specific silencing, was a major scientific revolution. This phenomenon known as RNA interference (RNAi), is believed to protect host genome against invasion by mobile genetic elements such as transposons and viruses. Gene silencing or RNAi has opened new potential opportunities to study the function of a gene in an organism. Furthermore, its therapeutic potential is being investigated in the field of sexually transmitted infections such as human immunodeficiency virus (HIV) and other diseases such as age-related macular degeneration (AMD), diabetes, hypercholesterolemia, respiratory disease, and cancer. This review will focus on the therapeutic potential of siRNA for the treatment and/or prevention of infectious diseases such as HIV, HPV, and HSV within the vaginal tract. Specifically, formulation design parameters to improve siRNA stability and therapeutic efficacy in the vaginal tract will be discussed along with challenges, advancements, and future directions of the field.
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Affiliation(s)
- Sidi Yang
- Faculty of Pharmacy, University of Manitoba, 750 McDermot Ave, Winnipeg, Manitoba, Canada
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Knoepfel SA, Abad A, Abad X, Fortes P, Berkhout B. Design of modified U1i molecules against HIV-1 RNA. Antiviral Res 2012; 94:208-16. [DOI: 10.1016/j.antiviral.2012.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 03/21/2012] [Accepted: 03/27/2012] [Indexed: 12/25/2022]
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Zou GM, Yoder MC. Application of RNA interference to study stem cell function: current status and future perspectives. Biol Cell 2012; 97:211-9. [PMID: 15715526 DOI: 10.1042/bc20040084] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RNA interference is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double-stranded RNA molecules. In the six years since the initial report, RNA interference has now been demonstrated to function in mammalian cells to alter gene expression, and has been used as a means for genetic discovery as well as a possible strategy for genetic correction. An equally popular topic over the past six years has been the proposal to utilize embryonic stem cells or adult stem cells as cell-based therapies for human diseases. The aim of this review is to provide a general overview of how RNA interference suppresses gene expression and to examine some published RNA interference approaches that have resulted in changes in stem cell function and suggest the possible clinical relevance of this work.
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Affiliation(s)
- Gang-Ming Zou
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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15
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PEGylated poly(ethylene imine) copolymer-delivered siRNA inhibits HIV replication in vitro. J Control Release 2012; 157:55-63. [DOI: 10.1016/j.jconrel.2011.09.059] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 07/19/2011] [Accepted: 09/04/2011] [Indexed: 01/08/2023]
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16
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Evans VA, Lal L, Akkina R, Solomon A, Wright E, Lewin SR, Cameron PU. Thymic plasmacytoid dendritic cells are susceptible to productive HIV-1 infection and efficiently transfer R5 HIV-1 to thymocytes in vitro. Retrovirology 2011; 8:43. [PMID: 21639903 PMCID: PMC3118182 DOI: 10.1186/1742-4690-8-43] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 06/03/2011] [Indexed: 01/28/2023] Open
Abstract
Background HIV-1 infection of the thymus contributes to the defective regeneration and loss of CD4+ T cells in HIV-1-infected individuals. As thymic dendritic cells (DC) are permissive to infection by HIV-1, we examined the ability of thymic DC to enhance infection of thymocytes which may contribute to the overall depletion of CD4+ T cells. We compared productive infection in isolated human thymic and blood CD11c+ myeloid DC (mDC) and CD123+ plasmacytoid DC (pDC) using enhanced green fluorescent protein (EGFP) CCR5 (R5)-tropic NL(AD8) and CXCR4 (X4)-tropic NL4-3 HIV-1 reporter viruses. Transfer of productive HIV-1 infection from thymic mDC and pDC was determined by culturing these DC subsets either alone or with sorted thymocytes. Results Productive infection was observed in both thymic pDC and mDC following exposure to R5 HIV-1 and X4 HIV-1. Thymic pDC were more frequently productively infected by both R5 and X4 HIV-1 than thymic mDC (p = 0.03; n = 6). Thymic pDC efficiently transferred productive R5 HIV-1 infection to both CD3hi (p = 0.01; mean fold increase of 6.5; n = 6) and CD3lo thymocytes (mean fold increase of 1.6; n = 2). In comparison, transfer of productive infection by thymic mDC was not observed for either X4 or R5 HIV-1. Conclusions The capacity of thymic pDC to efficiently transfer R5 HIV-1 to both mature and immature thymocytes that are otherwise refractory to R5 virus may represent a pathway to early infection and impaired production of thymocytes and CD4+ T cells in HIV-1-infected individuals.
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Affiliation(s)
- Vanessa A Evans
- Monash University, Department of Medicine, Central and Eastern Clinical School, Alfred Campus, Commercial Rd., Melbourne, Victoria 3004, Australia
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Angaji SA, Hedayati SS, Poor RH, Madani S, Poor SS, Panahi S. Application of RNA interference in treating human diseases. J Genet 2011; 89:527-37. [PMID: 21273705 DOI: 10.1007/s12041-010-0073-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Gene silencing can occur either through repression of transcription, termed transcriptional gene silencing (TGS), or through translation repression andmRNA degradation, termed posttranscriptional gene silencing (PTGS). PTGS results from sequence-specific mRNA degradation in the cytoplasm without dramatic changes in transcription of corresponding gene in nucleus. Both TGS and PTGS are used to regulate endogenous genes. Interestingly, mechanisms for gene silencing also protect the genome from transposons and viruses. In this paper, we first review RNAi mechanism and then focus on some of its applications in biomedical research such as treatment for HIV, viral hepatitis, cardiovascular and cerebrovascular diseases, metabolic disease, neurodegenerative disorders and cancer.
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Affiliation(s)
- S Abdolhamid Angaji
- Department of Biology, Tarbiat Moallem University, 31979-37551, Tehran, Iran.
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18
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Berkhout B, Sanders RW. Molecular strategies to design an escape-proof antiviral therapy. Antiviral Res 2011; 92:7-14. [PMID: 21513746 DOI: 10.1016/j.antiviral.2011.04.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/21/2011] [Accepted: 04/04/2011] [Indexed: 02/06/2023]
Abstract
Two antiviral approaches against the human immunodeficiency virus type 1 (HIV-1) were presented at the Antivirals Congress in Amsterdam. The common theme among these two separate therapeutic research lines is the wish to develop a durable therapy that prevents viral escape. We will present a brief overview of these two research lines and focus on our efforts to design an escape-proof anti-HIV therapy. The first topic concerns the class of HIV-1 fusion inhibitors, including the prototype T20 peptide and the improved versions T1249 and T2635, which were all developed by Trimeris-Roche. The selection of T20-resistant HIV-1 strains is a fairly easy evolutionary process that requires a single amino acid substitution in the peptide binding site of the viral envelope glycoprotein (Env) target. The selection of T1249-resistant HIV-1 strains was shown to require a more dramatic amino acid substitution in the viral Env protein, in particular the introduction of charged amino acid residues that cause resistance by charge-repulsion of the antiviral peptide. The third generation peptide T2635 remains active against all these HIV-1 escape variants because the charged residues within this peptide are "masked" by an introduced intra-helical salt bridge. This charge masking concept could facilitate the future design of escape-proof antiviral peptides. The second topic concerns the mechanism of RNA interference (RNAi) that we are currently employing to develop an antiviral gene therapy. One can make human T cells resistant to HIV-1 infection by a stable RNAi-inducing gene transfer, but the virus escapes under therapeutic pressure of a single inhibitor. Several options for a combinatorial RNAi attack to prevent viral escape will be discussed. The simultaneous use of multiple RNAi inhibitors turns out to be the most effective and durable strategy.
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Affiliation(s)
- Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, The Netherlands.
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Toward a durable treatment of HIV-1 infection using RNA interference. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 102:141-63. [PMID: 21846571 DOI: 10.1016/b978-0-12-415795-8.00001-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RNA interference (RNAi) is a cellular mechanism that mediates sequence-specific gene silencing at the posttranscriptional level. RNAi can be used as an antiviral approach against human pathogens. An attractive target for RNAi therapeutics is the human immunodeficiency virus type 1 (HIV-1), and the first clinical trial using a lentiviral gene therapy was initiated in early 2008. In this chapter, we focus on some basic principles of such an RNAi-based gene therapy against HIV-1. This includes the subjects of target site selection within the viral RNA genome, the phenomenon of viral escape, and therapeutic strategies to prevent viral escape. The latter antiescape strategies include diverse combinatorial RNAi approaches that are all directed against the HIV-1 RNA genome. As an alternative strategy, we also discuss the possibilities and restrictions of targeting cellular cofactors that are essential for virus replication, but less important for cell physiology.
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20
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Liu YP, Westerink JT, ter Brake O, Berkhout B. RNAi-inducing lentiviral vectors for anti-HIV-1 gene therapy. Methods Mol Biol 2011; 721:293-311. [PMID: 21431693 DOI: 10.1007/978-1-61779-037-9_18] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
RNA interference (RNAi)-based gene therapy for the treatment of HIV-1 infection provides a novel antiviral approach. For delivery of RNAi inducers to CD4+ T cells or CD34+ blood stem cells, lentiviral vectors are attractive because of their ability to transduce nondividing cells. In addition, lentiviral vectors allow stable transgene expression by inserting their cargo into the host cell genome. However, use of the HIV-1-based lentiviral vector also creates specific problems. The RNAi inducers can target HIV-1 sequences in the genomic RNA of the lentiviral vector. As the RNAi-inducing cassette contains palindromic sequences, the lentiviral vector RNA genome will have a perfect target sequence for the expressed RNAi inducer. Vectors encoding microRNAs face the putative problem that the vector RNA genome can be inactivated by Drosha processing. Here, we describe the design of lentiviral vectors with single or multiple RNAi-inducing antiviral cassettes. The possibility of titer reduction and some effective countermeasures are also presented.
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Affiliation(s)
- Ying Poi Liu
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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21
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DiGiusto DL, Krishnan A, Li L, Li H, Li S, Rao A, Mi S, Yam P, Stinson S, Kalos M, Alvarnas J, Lacey SF, Yee JK, Li M, Couture L, Hsu D, Forman SJ, Rossi JJ, Zaia JA. RNA-based gene therapy for HIV with lentiviral vector-modified CD34(+) cells in patients undergoing transplantation for AIDS-related lymphoma. Sci Transl Med 2010; 2:36ra43. [PMID: 20555022 DOI: 10.1126/scitranslmed.3000931] [Citation(s) in RCA: 290] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIDS patients who develop lymphoma are often treated with transplanted hematopoietic progenitor cells. As a first step in developing a hematopoietic cell-based gene therapy treatment, four patients undergoing treatment with these transplanted cells were also given gene-modified peripheral blood-derived (CD34(+)) hematopoietic progenitor cells expressing three RNA-based anti-HIV moieties (tat/rev short hairpin RNA, TAR decoy, and CCR5 ribozyme). In vitro analysis of these gene-modified cells showed no differences in their hematopoietic potential compared with nontransduced cells. In vitro estimates of successful expression of the anti-HIV moieties were initially as high as 22% but declined to approximately 1% over 4 weeks of culture. Ethical study design required that patients be transplanted with both gene-modified and unmanipulated hematopoietic progenitor cells obtained from the patient by apheresis. Transfected cells were successfully engrafted in all four infused patients by day 11, and there were no unexpected infusion-related toxicities. Persistent vector expression in multiple cell lineages was observed at low levels for up to 24 months, as was expression of the introduced small interfering RNA and ribozyme. Therefore, we have demonstrated stable vector expression in human blood cells after transplantation of autologous gene-modified hematopoietic progenitor cells. These results support the development of an RNA-based cell therapy platform for HIV.
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Affiliation(s)
- David L DiGiusto
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope, Duarte, CA 91010, USA
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22
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Liu YP, Vink MA, Westerink JT, Ramirez de Arellano E, Konstantinova P, Ter Brake O, Berkhout B. Titers of lentiviral vectors encoding shRNAs and miRNAs are reduced by different mechanisms that require distinct repair strategies. RNA (NEW YORK, N.Y.) 2010; 16:1328-39. [PMID: 20498457 PMCID: PMC2885682 DOI: 10.1261/rna.1887910] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 04/06/2010] [Indexed: 05/29/2023]
Abstract
RNAi-based gene therapy is a powerful approach to treat viral infections because of its high efficiency and sequence specificity. The HIV-1-based lentiviral vector system is suitable for the delivery of RNAi inducers to HIV-1 susceptible cells due to its ability to transduce nondividing cells, including hematopoietic stem cells, and its ability for stable transgene delivery into the host cell genome. However, the presence of anti-HIV short hairpin RNA (shRNA) and microRNA (miRNA) cassettes can negatively affect the lentiviral vector titers. We show that shRNAs, which target the vector genomic RNA, strongly reduced lentiviral vector titers but inhibition of the RNAi pathway via saturation could rescue vector production. The presence of miRNAs in the vector RNA genome (sense orientation) results in a minor titer reduction due to Drosha processing. A major cause for titer reduction of miRNA vectors is due to incompatibility of the cytomegalovirus promoter with the lentiviral vector system. Replacement of this promoter with an inducible promoter resulted in an almost complete restoration of the vector titer. We also showed that antisense poly(A) signal sequences can have a dramatic effect on the vector titer. These results show that not all sequences are compatible with the lentiviral vector system and that care should be taken in the design of lentiviral vectors encoding RNAi inducers.
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Affiliation(s)
- Ying Poi Liu
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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24
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Das AT, Berkhout B. HIV-1 evolution: frustrating therapies, but disclosing molecular mechanisms. Philos Trans R Soc Lond B Biol Sci 2010; 365:1965-73. [PMID: 20478891 PMCID: PMC2880118 DOI: 10.1098/rstb.2010.0072] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Replication of HIV-1 under selective pressure frequently results in the evolution of virus variants that replicate more efficiently under the applied conditions. For example, in patients on antiretroviral therapy, such evolution can result in variants that are resistant to the HIV-1 inhibitors, thus frustrating the therapy. On the other hand, virus evolution can help us to understand the molecular mechanisms that underlie HIV-1 replication. For example, evolution of a defective virus mutant can result in variants that overcome the introduced defect by restoration of the original sequence or by the introduction of additional mutations in the viral genome. Analysis of the evolution pathway can reveal the requirements of the element under study and help to understand its function. Analysis of the escape routes may generate new insight in the viral life cycle and result in the identification of unexpected biological mechanisms. We have developed in vitro HIV-1 evolution into a systematic research tool that allows the study of different aspects of the viral replication cycle. We will briefly review this method of forced virus evolution and provide several examples that illustrate the power of this approach.
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Affiliation(s)
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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Liang M, Kamata M, Chen KN, Pariente N, An DS, Chen ISY. Inhibition of HIV-1 infection by a unique short hairpin RNA to chemokine receptor 5 delivered into macrophages through hematopoietic progenitor cell transduction. J Gene Med 2010; 12:255-65. [PMID: 20186995 DOI: 10.1002/jgm.1440] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND We recently expressed a potent and noncytotoxic short hairpin (sh)RNA directed against chemokine (c-c motif) receptor 5 (CCR5) using lentiviral mediated transduction of CD34+ hematopoietic progenitor cells (HPCs) and demonstrated the stable reduction of CCR5 expression in T-lymphocytes. METHODS In the present study, we further assessed the activity of the shRNA through HPC transduction and differentiation into macrophages derived from fetal liver CD34+ (FL-CD34+) HPCs. Transduced lentiviral vector encoding the human CCR5 shRNA was stably maintained in FL-CD34+ cells and in the terminally differentiated macrophages using macrophage colony-stimulating factor, granulocyte macrophage colony-stimulating factor, interleukin-3 and stem cell factor. RESULTS Quantitative real-time polymerase chain reaction for CCR5 mRNA indicated over 90% reduction of CCR5 mRNA levels in CCR5 shRNA-transduced population. The cells with knockdown of CCR5 expression acquired resistance to R5 tropic HIV-1 NFN-SX strain. We also developed a novel approach utilizing a mCherry-CCR5 chimeric reporter to assess the effectiveness of CCR5 target down-regulation in macrophages directly. Both the shRNA and the reporter were maintained throughout HPC differentiation to macrophages without apparent cytotoxicity. CONCLUSIONS The present study demonstrates a novel method to simply and directly assess the function of small interfering RNA and the effective inhibition of HIV-1 infection by a potential potent shRNA to CCR5 delivered into macrophages derived from HPCs.
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Affiliation(s)
- Min Liang
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
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26
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Das AT, Jeeninga RE, Berkhout B. Possible applications for replicating HIV 1 vectors. ACTA ACUST UNITED AC 2010; 4:361-369. [PMID: 20582153 DOI: 10.2217/hiv.10.20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Since its discovery some 25 years ago, much has been learned about HIV type 1 and the molecular details of its replication cycle. This insight has been used to develop lentiviral vector systems that have advantages over conventional retroviral vector systems. For safety reasons, the lentiviral vector systems are replication incompetent and the risk of generating a replication competent virus has been minimized. Nevertheless, there may be certain applications for replication competent HIV based vector systems, and we will review our activities in this particular field. This includes the generation of a conditionally replicating HIV 1 variant as a safe live attenuated virus vaccine, the construction of mini HIV variants as cancer selective viruses for virotherapy against leukemia, and the use of a conditionally live anti HIV gene therapy vector. Although safety concerns will undoubtedly remain for the use of replication competent HIV based vector systems, some of the results in cell culture systems are very promising and warrant further testing in appropriate animal models.
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Affiliation(s)
- Atze T Das
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection & Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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Subramanya S, Kim SS, Manjunath N, Shankar P. RNA interference-based therapeutics for human immunodeficiency virus HIV-1 treatment: synthetic siRNA or vector-based shRNA? Expert Opin Biol Ther 2010; 10:201-13. [PMID: 20088715 PMCID: PMC3745298 DOI: 10.1517/14712590903448158] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IMPORTANCE OF THE FIELD Despite the clinical benefits of highly active antiretroviral therapy (HAART), the prospect of life-long antiretroviral treatment poses significant problems, which has spurred interest in developing new drugs and strategies to treat HIV infection and eliminate persistent viral reservoirs. RNAi has emerged as a therapeutic possibility for HIV. AREAS COVERED IN THIS REVIEW We discuss progress in overcoming hurdles to translating transient and stable RNAi enabling technologies to clinical application for HIV; covering the past 2 - 3 years. WHAT THE READER WILL GAIN HIV inhibition can be achieved by transfection of chemically or enzymatically synthesized siRNAs or by DNA-based vector systems expressing short hairpin RNAs (shRNAs) that are processed intracellularly into siRNA. We compare these approaches, focusing on technical and safety issues that will guide the choice of strategy for clinical use. TAKE HOME MESSAGE Introduction of synthetic siRNA into cells or its stable endogenous production using vector-driven shRNA have been shown to suppress HIV replication in vitro and, in some instances, in vivo. Each method has advantages and limitations in terms of ease of delivery, duration of silencing, emergence of escape mutants and potential toxicity. Both appear to have potential as future therapeutics for HIV, once the technical and safety issues of each approach are overcome.
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Affiliation(s)
- Sandesh Subramanya
- Department of Biomedical Sciences, Center of Excellence for Infectious Diseases, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905
| | - Sang-Soo Kim
- Department of Biomedical Sciences, Center of Excellence for Infectious Diseases, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905
| | - N Manjunath
- Department of Biomedical Sciences, Center of Excellence for Infectious Diseases, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905
| | - Premlata Shankar
- Department of Biomedical Sciences, Center of Excellence for Infectious Diseases, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905
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Abstract
RNAi is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double-strand RNA molecules. In the 11 years since the initial report, RNAi has now been demonstrated to function in mammalian cells to alter gene expression and used as a means for genetic discovery as well as a possible strategy for genetic correction and genetic therapy in cancer and other diseases. The aim of this review is to provide a general overview of how RNAi suppresses gene expression, examine some published RNAi approaches that have resulted in changes in stem cell function, and suggest the possible clinical relevance of this work in cancer therapy through targeting cancer stem cells.
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Affiliation(s)
- Gang-Ming Zou
- Department of Pathology and Otolaryngology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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29
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Abstract
Basic research in the field of molecular biology led to the discovery of the mechanism of RNA interference (RNAi) in Caenorhabditis elegans in 1998. RNAi is now widely appreciated as an important gene control mechanism in mammals, and several RNAi‐based gene‐silencing applications have already been used in clinical trials. In this review I will discuss RNAi approaches to inhibit the pathogenic human immunodeficiency virus type 1 (HIV‐1), which establishes a chronic infection that would most likely require a durable gene therapy approach. Viruses, such as HIV‐1, are particularly difficult targets for RNAi attack because they mutate frequently, which allows viral escape by mutation of the RNAi target sequence. Combinatorial RNAi strategies are required to prevent viral escape.
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Affiliation(s)
- Ben Berkhout
- Laboratory of Experimental Virology, Academic Medical Center, University of Amsterdam, the Netherlands.
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30
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Manjunath N, Haoquan W, Sandesh S, Premlata S. Lentiviral delivery of short hairpin RNAs. Adv Drug Deliv Rev 2009; 61:732-45. [PMID: 19341774 PMCID: PMC2789654 DOI: 10.1016/j.addr.2009.03.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 03/13/2009] [Indexed: 12/21/2022]
Abstract
In less than a decade after discovery, RNA interference-mediated gene silencing is already being tested as potential therapy in clinical trials for a number of diseases. Lentiviral vectors provide a means to express short hairpin RNA (shRNA) to induce stable and long-term gene silencing in both dividing and non-dividing cells and thus, are being intensively investigated for this purpose. However, induction of long-term shRNA expression can also cause toxicities by inducing off-target effects and interference with the endogenous micro-RNA (miRNA) pathway that regulates cellular gene expression. Recently, several advances have been made in the shRNA vector design to mimic cellular miRNA processing and to express multiplex siRNAs in a tightly regulated and reversible manner to overcome toxicities. In this review we describe some of these advances, focusing on the progress made in the development of lentiviral shRNA delivery strategies to combat viral infections.
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Affiliation(s)
- N Manjunath
- Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas 79905
| | - Wu Haoquan
- Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas 79905
| | - Subramanya Sandesh
- Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas 79905
| | - Shankar Premlata
- Paul L Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas 79905
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31
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Lipid-based systemic delivery of siRNA. Adv Drug Deliv Rev 2009; 61:721-31. [PMID: 19328215 DOI: 10.1016/j.addr.2009.03.003] [Citation(s) in RCA: 352] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Accepted: 03/10/2009] [Indexed: 01/13/2023]
Abstract
RNAi technology has brought a new category of treatments for various diseases including genetic diseases, viral diseases, and cancer. Despite the great versatility of RNAi that can down regulate almost any protein in the cells, the delicate and precise machinery used for silencing is the same. The major challenge indeed for RNAi-based therapy is the delivery system. In this review, we start with the uniqueness and mechanism of RNAi machinery and the utility of RNAi in therapeutics. Then we discuss the challenges in systemic siRNA delivery by dividing them into two categories-kinetic and physical barriers. At the end, we discuss different strategies to overcome these barriers, especially focusing on the step of endosome escape. Toxicity issues and current successful examples for lipid-based delivery are also included in the review.
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32
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Shinoda Y, Hieda K, Koyanagi Y, Suzuki Y. Efficient transduction of cytotoxic and anti-HIV-1 genes by a gene-regulatable lentiviral vector. Virus Genes 2009; 39:165-75. [DOI: 10.1007/s11262-009-0382-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Accepted: 06/12/2009] [Indexed: 01/25/2023]
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Von Eije KJ, Berkhout B. RNA-interference-based Gene Therapy Approaches to HIV Type-1 Treatment: Tackling the Hurdles from Bench to Bedside. ACTA ACUST UNITED AC 2009; 19:221-33. [DOI: 10.1177/095632020901900602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RNA interference (RNAi) is a cellular mechanism that can be induced by small interfering RNAs (siRNAs) to mediate sequence-specific gene silencing by cleavage of the targeted messenger RNA. RNAi can be used as an antiviral approach to silence HIV type-1 (HIV-1) through stable expression of precursors, such as short hairpin RNAs (shRNAs), which are processed into siRNAs that can elicit degradation of HIV-1 RNAs. At the beginning of 2008, the first clinical trial using a lentivirus with an RNA-based gene therapy against HIV-1 was initiated. The antiviral molecules in this gene therapy consist of three RNA effectors, one of which triggers the RNAi pathway. This review article focuses on the basic principles of an RNAi-based gene therapy against HIV-1, including delivery methods, target selection, viral escape possibilities, systems for multiplexing siRNAs to achieve a durable therapy and the in vitro and in vivo test systems to evaluate the efficacy and safety of such a therapy.
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Affiliation(s)
- Karin J Von Eije
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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34
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Abstract
BACKGROUND RNA interference (RNAi) can be employed as a potent antiviral mechanism. OBJECTIVE To discuss RNAi approaches to target pathogenic human viruses causing acute or chronic infections, in particular RNAi gene therapy against HIV-1. METHODS A review of relevant literature. RESULTS/CONCLUSIONS The future of antiviral RNAi therapeutics is very promising. RNAi was discovered only a decade ago, and although we are still in the early days, the first clinical trials are already ongoing.
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Affiliation(s)
- Ben Berkhout
- Academic Medical Center of the University of Amsterdam, Center for Infection and Immunity Amsterdam (CINIMA), Department of Medical Microbiology, Laboratory of Experimental Virology, Amsterdam, The Netherlands.
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35
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Abstract
Therapeutic options against the human immunodeficiency virus type 1 (HIV-1) continue to expand with the development of new drugs and new therapeutic strategies. Nevertheless, management of HIV-1 infected individuals has become increasingly complex. The emergence of drug-resistant variants, the growing recognition of the long-term toxicity of antiretroviral therapies and the persistence of viral reservoirs justify the continued efforts to develop new anti-HIV-1 strategies. Recent advances regarding the utility of RNA-mediated interference (RNAi) to specifically inhibit HIV-1 replication have opened new possibilities for the development of gene-based therapies against HIV-1 infection. Here, the recent advances in siRNA-based therapies are reviewed.
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Baba K, Goto-Koshino Y, Mizukoshi F, Setoguchi-Mukai A, Fujino Y, Ohno K, Tsujimoto H. Inhibition of the replication of feline immunodeficiency virus by lentiviral vector-mediated RNA interference in feline cell lines. J Vet Med Sci 2008; 70:777-83. [PMID: 18772551 DOI: 10.1292/jvms.70.777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RNA interference (RNAi) is a sequence-specific RNA degradation process. To inhibit feline immunodeficiency virus (FIV) replication by RNAi, we generated a lentiviral vector expressing a short hairpin RNA (shRNA) that targeted the gag gene of FIV (shGag). shGag transfer significantly inhibited viral replication in cell lines that were chronically infected with FIV, i.e., the 3201/UK8 low, 3201/UK8 high, FL4, and CRFK/FIV cell lines. Moreover, 3201 cells were transduced with the lentiviral vectors and then inoculated with FIV. Although the amount of FIV proviral DNA in shGag-transduced cells was similar to that in the cells transduced with unrelated shRNA or mock-transduced cells, the amount of reverse transcriptase (RT) activity was significantly reduced in the culture supernatant of shGag-expressing cells from 15 to 27 days after inoculation. Thirty days after inoculation, no significant difference was observed in the RT activities but virus with a mutation in the target region of shGag was detected in approximately 21% of the replicated viruses. Therefore, abolishment of the silencing effect of shGag may be due to reasons other than the emergence of escape mutants. These results are useful for developing an RNAi-based gene therapy strategy for controlling FIV infection.
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Affiliation(s)
- Kenji Baba
- Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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37
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Kumar P, Ban HS, Kim SS, Wu H, Pearson T, Greiner DL, Laouar A, Yao J, Haridas V, Habiro K, Yang YG, Jeong JH, Lee KY, Kim YH, Kim SW, Peipp M, Fey GH, Manjunath N, Shultz LD, Lee SK, Shankar P. T cell-specific siRNA delivery suppresses HIV-1 infection in humanized mice. Cell 2008; 134:577-86. [PMID: 18691745 PMCID: PMC2943428 DOI: 10.1016/j.cell.2008.06.034] [Citation(s) in RCA: 455] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Revised: 05/08/2008] [Accepted: 06/12/2008] [Indexed: 11/17/2022]
Abstract
Evaluation of the therapeutic potential of RNAi for HIV infection has been hampered by the challenges of siRNA delivery and lack of suitable animal models. Using a delivery method for T cells, we show that siRNA treatment can dramatically suppress HIV infection. A CD7-specific single-chain antibody was conjugated to oligo-9-arginine peptide (scFvCD7-9R) for T cell-specific siRNA delivery in NOD/SCIDIL2rgamma-/- mice reconstituted with human lymphocytes (Hu-PBL) or CD34+ hematopoietic stem cells (Hu-HSC). In HIV-infected Hu-PBL mice, treatment with anti-CCR5 (viral coreceptor) and antiviral siRNAs complexed to scFvCD7-9R controlled viral replication and prevented the disease-associated CD4 T cell loss. This treatment also suppressed endogenous virus and restored CD4 T cell counts in mice reconstituted with HIV+ peripheral blood mononuclear cells. Moreover, scFvCD7-9R could deliver antiviral siRNAs to naive T cells in Hu-HSC mice and effectively suppress viremia in infected mice. Thus, siRNA therapy for HIV infection appears to be feasible in a preclinical animal model.
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Affiliation(s)
- Priti Kumar
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Hong-Seok Ban
- Department of Bioengineering and Hanyang Fusion Materials Program,, Hanyang University, Seoul, 133-791, Korea
| | - Sang-Soo Kim
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Haoquan Wu
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Todd Pearson
- Department of Medicine, Division of Diabetes, University of Massachusetts Medical School, Worcester, 01605, MA, USA
| | - Dale. L. Greiner
- Department of Medicine, Division of Diabetes, University of Massachusetts Medical School, Worcester, 01605, MA, USA
| | - Amale Laouar
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Jiahong Yao
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Viraga Haridas
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Katsuyoshi Habiro
- Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Yong-Guang Yang
- Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA
| | - Ji-Hoon Jeong
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Kuen-Yong Lee
- Department of Bioengineering and Hanyang Fusion Materials Program,, Hanyang University, Seoul, 133-791, Korea
| | - Yong-Hee Kim
- Department of Bioengineering and Hanyang Fusion Materials Program,, Hanyang University, Seoul, 133-791, Korea
| | - Sung Wan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Matthias Peipp
- Division of Stem Cell Transplantation and Immunotherapy, Christian-Albrechts-University, Kiel, Germany
| | - Georg H. Fey
- University of Erlangen, D 91058, Erlangen, Germany
| | - N Manjunath
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | | | - Sang-Kyung Lee
- Department of Bioengineering and Hanyang Fusion Materials Program,, Hanyang University, Seoul, 133-791, Korea
| | - Premlata Shankar
- Immune Disease Institute and Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
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38
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Anderson J, Akkina R. Human immunodeficiency virus type 1 restriction by human-rhesus chimeric tripartite motif 5alpha (TRIM 5alpha) in CD34(+) cell-derived macrophages in vitro and in T cells in vivo in severe combined immunodeficient (SCID-hu) mice transplanted with human fetal tissue. Hum Gene Ther 2008; 19:217-28. [PMID: 18279037 DOI: 10.1089/hum.2007.108] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Species-specific innate resistance against viral infections offers novel avenues for antiviral therapeutics. The retroviral restriction factor TRIM5alpha (tripartite motif 5alpha protein) has been shown to potently restrict human immunodeficiency virus (HIV)-1 infection in otherwise susceptible cell lines and CD34(+) cell-derived macrophages. A 13-amino acid patch in the C-terminal B30.2 (SPRY) domain of rhesus macaque TRIM5alpha has been shown to be involved in HIV-1 capsid recognition and is critical for viral inhibition. A chimeric human-rhesus TRIM5alpha (TRIM5alpha-HRH) was generated by replacing an 11-amino acid patch in the human isoform with the rhesus 13-amino acid patch. Here we show that lentiviral vector expression of this human-rhesus chimera in HIV-1-permissive MAGI-CXCR4 cells conferred resistance as well as a selective survival advantage on HIV-1 challenge. To apply these findings in a stem cell gene therapy setting, TRIM5alpha-HRH was expressed in CD34(+) cell-derived macrophages in vitro and in SCID-hu mouse-derived thymocytes in vivo. On viral challenge, transgenic macrophages and thymocytes were highly resistant to HIV-1 compared with control cells. Normal development of TRIM5alpha-HRH-expressing macrophages and in vivo-derived T cells was also observed by phenotypic flow cytometric analysis. These results demonstrate the efficacy of TRIM5alpha-HRH in a stem cell setting and its further advancement for use in gene therapy applications.
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Affiliation(s)
- Joseph Anderson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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39
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Abstract
Since the discovery that the triggers for RNA interference (RNAi), small interfering RNAs, could mediate silencing in mammalian cells without triggering a toxic response, RNAi has become the standard tool for sequence-specific knockdown of gene expression in molecular biology. This is due in part to the development of methods for promoter-based expression of RNAi triggers that can mediate stable silencing in mammalian cells. Numerous systems with slightly different characteristics exist, but despite incredible progress in a field that moves very rapidly, challenges still remain. The biggest challenge is to successfully and safely apply RNAi in vivo. Aside from potential issues of delivery, which is one of the most important considerations, successful application of short hairpin RNAs (shRNAs) in vivo requires expression systems that yield potent and specific knockdown of the target in the absence of toxicity. With a couple of exceptions, the current systems available for shRNA expression have not generally resulted in unexpected toxicities, while still providing strong knockdown of the intended targets; however, we do not know enough about how sequence-specific off-target effects will affect various cell and tissue types, or to what extent ectopic expression of RNAi triggers will perturb the endogenous RNAi mechanisms.
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Affiliation(s)
- John J Rossi
- Division of Molecular Biology, Beckman Research Institute of the City of Hope, Graduate School of Biological Sciences, Duarte, CA 91010, USA.
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Srinivasakumar N. Substitution of the Rev-response element in an HIV-1-based gene delivery system with that of SIVmac239 allows efficient delivery of Rev M10 into T-lymphocytes. AIDS Res Ther 2008; 5:11. [PMID: 18534033 PMCID: PMC2438438 DOI: 10.1186/1742-6405-5-11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 06/05/2008] [Indexed: 12/27/2022] Open
Abstract
Background Human immunodeficiency virus type 1 (HIV-1)-based gene delivery systems are popular due to their superior efficiency of transduction of primary cells. However, these systems cannot be readily used for delivery of anti-HIV-1 genes that target constituents of the packaging system itself due to inimical effects on vector titer. Here we describe HIV-1-based packaging systems containing the Rev-response element (RRE), of simian immunodeficiency virus (SIV) in place of the HIV-1 RRE. The SIV RRE-containing packaging systems were used to deliver the anti-Rev gene, Rev M10, into HIV-1 susceptible target cells. Results An HIV-1 based packaging system was created using either a 272- or 1045-nucleotide long RRE derived from the molecular clone SIVmac239. The 1045-nucleotide SIV RRE-containing HIV-1 packaging system provided titers comparable to that of the HIV-1 RRE-based one. Moreover, despite the use of HIV-1 Rev for production of vector stocks, this packaging system was found to be relatively refractory to the inhibitory effects of Rev M10. Correspondingly, the SIV RRE-based packaging system provided 34- to 130-fold higher titers than the HIV-1 RRE one when used for packaging a gene transfer vector encoding Rev-M10. Jurkat T-cells, gene modified with Rev M10 encoding HIV-1 vectors, upon challenge with replication defective HIV-1 in single-round infection experiments, showed diminished production of virus particles. Conclusion A simple modification of an HIV-1 gene delivery system, namely, replacement of HIV-1 RRE with that of SIV, allowed efficient delivery of Rev M10 transgene into T-cell lines for intracellular immunization against HIV-1 replication.
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Yang Y, Wu C, Wu J, Nerurkar VR, Yanagihara R, Lu Y. Inhibition of West Nile Virus replication by retrovirus-delivered small interfering RNA in human neuroblastoma cells. J Med Virol 2008; 80:930-6. [PMID: 18360908 DOI: 10.1002/jmv.21164] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
West Nile virus (WNV) has been responsible for the largest outbreaks of arboviral encephalitis in U.S. history. No specific drug is currently available for the effective treatment of WNV infection. To exploit RNA interference as a potential therapeutic approach, a Moloney murine leukemia virus-based retrovirus vector was used to effectively deliver WNV-specific small interfering RNA (siRNA) into human neuroblastoma HTB-11 cells. Viral plaque assays demonstrated that transduced cells were significantly refractory to WNV replication, as compared to untransduced control cells (P < 0.05), which correlated with the reduced expression of target viral genes and respective viral proteins. Therefore, retrovirus-mediated delivery of siRNA for gene silencing can be used to study the specific functions of viral genes associated with replication and may have potential therapeutic applications.
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Affiliation(s)
- Yongbo Yang
- Department of Public Health Sciences, John A. Burns School of Medicine, University of Hawai'i, Honolulu, Hawaii, USA
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42
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Abstract
Life-prolonging antiretroviral therapy remarkably reduces viral load, but it does not eradicate the virus. An important obstacle preventing virus clearance is the presence of latent virion reservoirs in the host. However, new promising antiviral approaches are emerging, and a number of host cell factors involved in the disease progression and control of HIV-1 replication have been recently discovered. For instance, the RNA interference (RNAi) mechanism, besides many functions conserved throughout evolution, works as a defence mechanism against noxious transcripts which may provide a new tool to block viral replication. The recent definition of basic RNAi mechanisms, as well as the discovery of micro RNAs (microRNAs) encoded by the host cell genome and by HIV-1, also suggest that RNAi may be involved in the control of HIV replication.
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Affiliation(s)
- Luis Isamu Barros Kanzaki
- Laboratory of Molecular Pharmacology, Faculty of Health Science, University of Brasília, Brasília, Brazil
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43
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ter Brake O, Berkhout B. Lentiviral vectors that carry anti-HIV shRNAs: problems and solutions. J Gene Med 2008; 9:743-50. [PMID: 17628029 DOI: 10.1002/jgm.1078] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND HIV-1 replication can be inhibited with RNA interference (RNAi) by expression of short hairpin RNA (shRNA) from a lentiviral vector. Because lentiviral vectors are based on HIV-1, viral sequences in the vector system are potential targets for the antiviral shRNAs. Here, we investigated all possible routes by which shRNAs can target the lentiviral vector system. METHODS Expression cassettes for validated shRNAs with targets within HIV-1 Leader, Gag-Pol, Tat/Rev and Nef sequences were inserted in the lentiviral vector genome. Third-generation self-inactivating HIV-1-based lentiviral vectors were produced and lentiviral vector capsid production and transduction titer determined. RESULTS RNAi against HIV-1 sequences within the vector backbone results in a reduced transduction titer while capsid production was unaffected. The notable exception is self-targeting of the shRNA encoding sequence, which does not affect transduction titer. This is due to folding of the stable shRNA hairpin structure, which masks the target for the RNAi machinery. Targeting of Gag-Pol mRNA reduces both capsid production and transduction titer, which was improved with a human codon-optimized Gag-Pol construct. When Rev mRNA was targeted, no reduction in capsid production and transduction titer was observed. CONCLUSIONS Lentiviral vector titers can be negatively affected when shRNAs against the vector backbone and the Gag-Pol mRNA are expressed during lentiviral vector production. Titer reductions due to targeting of the Gag-Pol mRNA can be avoided with a human codon-optimized Gag-Pol packaging plasmid. The remaining targets in the vector backbone may be modified by point mutations to resist RNAi-mediated degradation during vector production.
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Affiliation(s)
- Olivier ter Brake
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center of the University of Amsterdam, The Netherlands
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Abstract
Stem cells have been the focus of numerous investigations to treat diseases as far ranging as diabetes, chronic heart failure and multiple sclerosis over the past decade. The process of stem-cell-based repair of acute injury involves homing and engrafting of the stem cell of interest to the site of injury followed by either differentiation of the stem cell to indigenous end-organ cells or liberation of paracrine factors that lead to preservation and/or optimization of organ function. Recognition of the ability of stem cells to home to sites of acute injury suggests that, if appropriately defined and harnessed, stem cell homing could serve as a means of local drug delivery through the infusion of genetically engineering stem cells that secrete gene products of interest. The authors have recently demonstrated the use of this approach in preclinical studies of acute myocardial function. In addition, the use of engineered cells that home to appropriate niches have been used to correct genetic deficiency states (i.e., severe combined immunodeficiency, diabetes mellitus) in patients with otherwise chronic debilitating diseases. This review focuses on exploiting stem cell homing for gene transfer and on the state of the art and the challenges that face the field.
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Affiliation(s)
- Marc S Penn
- Skirball Laboratory for Cardiovascular Cellular Therapeutics, Department of Cardiovascular Medicine, NE3, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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45
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Dieckhoff B, Petersen B, Kues WA, Kurth R, Niemann H, Denner J. Knockdown of porcine endogenous retrovirus (PERV) expression by PERV-specific shRNA in transgenic pigs. Xenotransplantation 2008; 15:36-45. [DOI: 10.1111/j.1399-3089.2008.00442.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The intranasal administration of siRNA has opened new vistas in drug delivery and respiratory therapy. In this strategy, synthetic siRNA with or without chemical modifications can be applied intranasally. Various delivery vehicles have been tested and optimized. With a few exceptions, all promote significant uptake of siRNA into the lung tissue and offer protection against respiratory viruses such as respiratory syncytial virus (RSV), parainfluenza virus (PIV), and influenza virus. No major adverse immune reaction has been encountered. Nasally applied siRNA remains within the lung and does not have systemic access, as judged by its absence in other major organs such as the lung, liver, heart, and kidney. We provide techniques for using the nose as a specific route for siRNA delivery into the lung of laboratory animals, which has enormous potential for clinical applications.
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Taylor JA, Vojtech L, Bahner I, Kohn DB, Laer DV, Russell DW, Richard RE. Foamy virus vectors expressing anti-HIV transgenes efficiently block HIV-1 replication. Mol Ther 2007; 16:46-51. [PMID: 17955023 DOI: 10.1038/sj.mt.6300335] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gene therapy has the potential to control human immunodeficiency virus (HIV) in patients who do not respond to traditional antiviral therapy. In this study, we tested foamy virus (FV) vectors expressing three anti-HIV transgenes, both individually and in a combination vector. The transgenes tested in this study are RevM10, a dominant negative version of the viral rev protein, Sh1, a short hairpin RNA directed against a conserved overlapping sequence of tat and rev, and membrane-associated C46 (maC46), a membrane-attached peptide that blocks HIV cell entry. FV vectors efficiently transduce hematopoietic stem cells and, unlike lentivirus (LV) vectors, do not share viral proteins with HIV. The titers of the FV vectors described in this study were not affected by anti-HIV transgenes. On a direct comparison of FV vectors expressing the individual transgenes, entry inhibition using the maC46 transgene was found to be the most effective at blocking HIV replication. A clinically relevant FV vector expressing three anti-HIV transgenes effectively blocked HIV infection in primary macrophages derived from transduced, peripheral blood CD34-selected cells and in a cell line used for propagating HIV, CEMx174. These results suggest that there are potential benefits of using FV vectors in HIV gene therapy.
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Affiliation(s)
- Jason A Taylor
- Department of Medicine, University of Washington, Seattle, Washington, USA
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Braun SE, Shi X, Qiu G, Wong F, Joshi PJ, Prasad VR, Johnson RP. Instability of retroviral vectors with HIV-1-specific RT aptamers due to cryptic splice sites in the U6 promoter. AIDS Res Ther 2007; 4:24. [PMID: 17941994 PMCID: PMC2211285 DOI: 10.1186/1742-6405-4-24] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 10/17/2007] [Indexed: 11/10/2022] Open
Abstract
Background Internal polymerase III promoters in retroviral vectors have been used extensively to express short RNA sequences, such as ribozymes, RNA aptamers or short interfering RNA inhibitors, in various positions and orientations. However, the stability of these promoters in the reverse orientation has not been rigorously evaluated. Results A series of retroviral vectors was generated carrying the U6+1 promoter with 3 different HIV-1 RT-specific RNA aptamers and one control aptamer, all in the reverse orientation. After shuttle packaging, the CD4+ cell line CEMx174 was transduced with each vector, selected for expression of GFP, and challenged with HIV-1. We did not observe inhibition of HIV-1 replication in these transduced populations. PCR amplification of the U6+1 promoter-RNA aptamer inhibitor cassette from transduced CEMx174 cells and RT-PCR amplification from transfected Phoenix (amphotropic) packaging cells showed two distinct products: a full-length product of the expected size as well as a truncated product. The sequence of the full-length PCR product was identical to the predicted amplicon sequence. However, sequencing of the truncated product revealed a 139 bp deletion in the U6 promoter. This deletion decreased transcriptional activity of the U6 promoter. Analysis of the deleted sequences from the U6 promoter in the antisense direction indicated consensus splice donor, splice acceptor and branch point sequences. Conclusion The existence of a cryptic splice site in the U6 promoter when expressed in a retroviral vector in the reverse orientation generates deletions during packaging and may limit the utility of this promoter for expression of small RNA inhibitors.
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Asparuhova MB, Marti G, Liu S, Serhan F, Trono D, Schümperli D. Inhibition of HIV-1 multiplication by a modified U7 snRNA inducing Tat and Rev exon skipping. J Gene Med 2007; 9:323-34. [PMID: 17474072 DOI: 10.1002/jgm.1027] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The HIV-1 regulatory proteins Tat and Rev are encoded by multiply spliced mRNAs that differ by the use of alternative 3' splice sites at the beginning of the internal exon. If these internal exons are skipped, the expression of these genes, and hence HIV-1 multiplication, should be inhibited. We have previously developed a strategy, based on antisense derivatives of U7 small nuclear RNA, that allows us to induce the skipping of an internal exon in virtually any gene. Here, we have successfully applied this approach to induce a partial skipping of the Tat, Rev (and Nef) internal exons. Three functional U7 constructs were subcloned into a lentiviral vector. Two of them strongly reduced the efficiency of lentiviral particle production compared to vectors carrying either no U7 insert or unrelated U7 cassettes. This defect could be partly or fully compensated by coexpressing Rev from an unspliced mRNA in the producing cell line. Upon stable transduction into CEM-SS or CEM T-lymphocytes, the most efficient of these constructs inhibits HIV-1 multiplication. Although the inhibition is not complete, it is more efficient in combination with another mechanism inhibiting HIV multiplication. Therefore, this new approach targeting HIV-1 regulatory genes at the level of pre-mRNA splicing, in combination with other antiviral strategies, may be a useful new tool in the fight against HIV/AIDS.
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Affiliation(s)
- Maria B Asparuhova
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland
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Kuruvilla JG, Troyer RM, Devi S, Akkina R. Dengue virus infection and immune response in humanized RAG2(-/-)gamma(c)(-/-) (RAG-hu) mice. Virology 2007; 369:143-52. [PMID: 17707071 DOI: 10.1016/j.virol.2007.06.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 05/31/2007] [Accepted: 06/06/2007] [Indexed: 11/17/2022]
Abstract
Dengue viral (DENV) pathogenesis and vaccine studies are hampered by the lack of an ideal animal model mimicking human disease and eliciting an adaptive human immune response. Although currently available animal models have been very useful in dissecting some key aspects of disease pathogenesis, a major limitation with these is the lack of a human immune response. In this study, we sought to overcome this difficulty by utilizing a novel mouse model that permits multi-lineage human hematopoiesis and immune response following transplantation with human hematopoietic stem cells. To generate immunocompetent humanized mice, neonatal RAG2(-/-)gamma(c)(-/-) mice were xenografted with human CD34+ hematopoietic stem cells, resulting in de novo development of major functional cells of the human adaptive immune system. To evaluate susceptibility to dengue viral infection, humanized mice were challenged with DEN-2 serotype. Viremia lasting up to 3 weeks was detected in infected mice with viral titers reaching up to 10(6.3) RNA copies/ml. Fever characteristic of dengue was also noted in infected mice. Presence of human anti-dengue antibodies was evaluated using an antibody capture ELISA. Anti-dengue IgM was first detected by 2 weeks post-infection followed by IgG at 6 weeks. Sera from some of the infected mice were also found to be capable of dengue virus neutralization. Infected mouse sera showed reactivity with the viral envelope and capsid proteins in immunoprecipitation assay. These results demonstrate for the first time that humanized mice are capable of dengue viral primary human immune responses thus paving the way for new dengue immunopathogenesis and vaccine studies.
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Affiliation(s)
- Jes G Kuruvilla
- Department of Microbiology, Immunology and Pathology, 1619 Campus Delivery, Colorado State University, Fort Collins, CO 80523-1619, USA
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