1001
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mRNA-engineered mesenchymal stem cells for targeted delivery of interleukin-10 to sites of inflammation. Blood 2013; 122:e23-32. [PMID: 23980067 DOI: 10.1182/blood-2013-04-495119] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are promising candidates for cell-based therapy to treat several diseases and are compelling to consider as vehicles for delivery of biological agents. However, MSCs appear to act through a seemingly limited "hit-and-run" mode to quickly exert their therapeutic impact, mediated by several mechanisms, including a potent immunomodulatory secretome. Furthermore, MSC immunomodulatory properties are highly variable and the secretome composition following infusion is uncertain. To determine whether a transiently controlled antiinflammatory MSC secretome could be achieved at target sites of inflammation, we harnessed mRNA transfection to generate MSCs that simultaneously express functional rolling machinery (P-selectin glycoprotein ligand-1 [PSGL-1] and Sialyl-Lewis(x) [SLeX]) to rapidly target inflamed tissues and that express the potent immunosuppressive cytokine interleukin-10 (IL-10), which is not inherently produced by MSCs. Indeed, triple-transfected PSGL-1/SLeX/IL-10 MSCs transiently increased levels of IL-10 in the inflamed ear and showed a superior antiinflammatory effect in vivo, significantly reducing local inflammation following systemic administration. This was dependent on rapid localization of MSCs to the inflamed site. Overall, this study demonstrates that despite the rapid clearance of MSCs in vivo, engineered MSCs can be harnessed via a "hit-and-run" action for the targeted delivery of potent immunomodulatory factors to treat distant sites of inflammation.
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1002
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Bernal JA. RNA-based tools for nuclear reprogramming and lineage-conversion: towards clinical applications. J Cardiovasc Transl Res 2013; 6:956-68. [PMID: 23852582 PMCID: PMC3838600 DOI: 10.1007/s12265-013-9494-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 06/21/2013] [Indexed: 02/06/2023]
Abstract
The therapeutic potential of induced pluripotent stem cells (iPSCs) is well established. Safety concerns remain, however, and these have driven considerable efforts aimed at avoiding host genome alteration during the reprogramming process. At present, the tools used to generate human iPSCs include (1) DNA-based integrative and non-integrative methods and (2) DNA-free reprogramming technologies, including RNA-based approaches. Because of their combined efficiency and safety characteristics, RNA-based methods have emerged as the most promising tool for future iPSC-based regenerative medicine applications. Here, I will discuss novel recent advances in reprogramming technology, especially those utilizing the Sendai virus (SeV) and synthetic modified mRNA. In the future, these technologies may find utility in iPSC reprogramming for cellular lineage-conversion, and its subsequent use in cell-based therapies.
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Affiliation(s)
- Juan A Bernal
- Cardiovascular Development and Repair Department, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Melchor Fernández Almagro 3, 28029, Madrid, Spain,
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1003
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1004
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Geall AJ, Mandl CW, Ulmer JB. RNA: the new revolution in nucleic acid vaccines. Semin Immunol 2013; 25:152-9. [PMID: 23735226 DOI: 10.1016/j.smim.2013.05.001] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 04/29/2013] [Accepted: 05/03/2013] [Indexed: 01/02/2023]
Abstract
Nucleic acid vaccines have the potential to address issues of safety and effectiveness sometimes associated with vaccines based on live attenuated viruses and recombinant viral vectors. In addition, methods to manufacture nucleic acid vaccines are suitable as generic platforms and for rapid response, both of which will be very important for addressing newly emerging pathogens in a timely fashion. Plasmid DNA is the more widely studied form of nucleic acid vaccine and proof of principle in humans has been demonstrated, although no licensed human products have yet emerged. The RNA vaccine approach, based on mRNA and engineered RNA replicons derived from certain RNA viruses, is gaining increased attention and several vaccines are under investigation for infectious diseases, cancer and allergy. Human clinical trials are underway and the prospects for success are bright.
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Affiliation(s)
- Andrew J Geall
- Novartis Vaccines & Diagnostics, Cambridge, MA 02139, USA.
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1005
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Sibbritt T, Patel HR, Preiss T. Mapping and significance of the mRNA methylome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:397-422. [PMID: 23681756 DOI: 10.1002/wrna.1166] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 03/20/2013] [Accepted: 03/22/2013] [Indexed: 12/25/2022]
Abstract
Internal methylation of eukaryotic mRNAs in the form of N6-methyladenosine (m(6)A) and 5-methylcytidine (m(5)C) has long been known to exist, but progress in understanding its role was hampered by difficulties in identifying individual sites. This was recently overcome by high-throughput sequencing-based methods that mapped thousands of sites for both modifications throughout mammalian transcriptomes, with most sites found in mRNAs. The topology of m(6)A in mouse and human revealed both conserved and variable sites as well as plasticity in response to extracellular cues. Within mRNAs, m(5)C and m(6)A sites were relatively depleted in coding sequences and enriched in untranslated regions, suggesting functional interactions with post-transcriptional gene control. Finer distribution analyses and preexisting literature point toward roles in the regulation of mRNA splicing, translation, or decay, through an interplay with RNA-binding proteins and microRNAs. The methyltransferase (MTase) METTL3 'writes' m(6)A marks on mRNA, whereas the demethylase FTO can 'erase' them. The RNA:m(5)C MTases NSUN2 and TRDMT1 have roles in tRNA methylation but they also act on mRNA. Proper functioning of these enzymes is important in development and there are clear links to human disease. For instance, a common variant of FTO is a risk allele for obesity carried by 1 billion people worldwide and mutations cause a lethal syndrome with growth retardation and brain deficits. NSUN2 is linked to cancer and stem cell biology and mutations cause intellectual disability. In this review, we summarize the advances, open questions, and intriguing possibilities in this emerging field that might be called RNA modomics or epitranscriptomics.
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Affiliation(s)
- Tennille Sibbritt
- Genome Biology Department, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
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1006
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Ge J, Yu YT. RNA pseudouridylation: new insights into an old modification. Trends Biochem Sci 2013; 38:210-8. [PMID: 23391857 PMCID: PMC3608706 DOI: 10.1016/j.tibs.2013.01.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/22/2012] [Accepted: 01/07/2013] [Indexed: 12/18/2022]
Abstract
Pseudouridine is the most abundant post-transcriptionally modified nucleotide in various stable RNAs of all organisms. Pseudouridine is derived from uridine via base-specific isomerization, resulting in an extra hydrogen-bond donor that distinguishes it from other nucleotides. In eukaryotes, uridine-to-pseudouridine isomerization is catalyzed primarily by box H/ACA RNPs, ribonucleoproteins that act as pseudouridylases. When introduced into RNA, pseudouridine contributes significantly to RNA-mediated cellular processes. It was recently discovered that pseudouridylation can be induced by stress, suggesting a regulatory role for pseudouridine. It has also been reported that pseudouridine can be artificially introduced into mRNA by box H/ACA RNPs and that such introduction can mediate nonsense-to-sense codon conversion, thus demonstrating a new means of generating coding or protein diversity.
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Affiliation(s)
- Junhui Ge
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
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1007
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Andries O, Filette MD, De Smedt SC, Demeester J, Poucke MV, Peelman L, Sanders NN. Innate immune response and programmed cell death following carrier-mediated delivery of unmodified mRNA to respiratory cells. J Control Release 2013; 167:157-66. [DOI: 10.1016/j.jconrel.2013.01.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/14/2013] [Accepted: 01/30/2013] [Indexed: 12/12/2022]
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1008
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Abstract
Induced pluripotent stem (iPS) cells hold the potential to revolutionize regenerative medicine through their capacity to generate cells of diverse lineages for future patient-specific cell-based therapies. To facilitate the transition of iPS cells to clinical practice, a variety of technologies have been developed for transgene-free pluripotency reprogramming. We recently reported efficient iPS cell generation from human fibroblasts using synthetic modified mRNAs. Here we describe a stepwise protocol for the generation of modified mRNA-derived iPS cells from primary human fibroblasts, focusing on the critical parameters including medium choice, quality control, and optimization steps needed for synthesizing modified mRNAs encoding reprogramming factors and introducing these into cells over the course of 2-3 weeks to ensure successful reprogramming. The protocol described herein is for reprogramming of human fibroblasts to pluripotency; however, the properties of modified mRNA make it a powerful platform for protein expression, which has broad applicability in directed differentiation, cell fate specification and therapeutic applications.
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1009
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Gilboa E. mRNA leapfrogs DNA to show promise for therapeutic gene transfer. Mol Ther 2013; 20:694-5. [PMID: 22472978 DOI: 10.1038/mt.2012.31] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Eli Gilboa
- Department of Microbiology and Immunology, Dodson Interdisciplinary Immunotherapy Institute, and Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA.
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1010
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Uchida S, Itaka K, Uchida H, Hayakawa K, Ogata T, Ishii T, Fukushima S, Osada K, Kataoka K. In vivo messenger RNA introduction into the central nervous system using polyplex nanomicelle. PLoS One 2013; 8:e56220. [PMID: 23418537 PMCID: PMC3571986 DOI: 10.1371/journal.pone.0056220] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 01/07/2013] [Indexed: 01/09/2023] Open
Abstract
Messenger RNA (mRNA) introduction is a promising approach to produce therapeutic proteins and peptides without any risk of insertion mutagenesis into the host genome. However, it is difficult to introduce mRNA in vivo mainly because of the instability of mRNA under physiological conditions and its strong immunogenicity through the recognition by Toll-like receptors (TLRs). We used a novel carrier based on self-assembly of a polyethylene glycol (PEG)-polyamino acid block copolymer, polyplex nanomicelle, to administer mRNA into the central nervous system (CNS). The nanomicelle with 50 nm in diameter has a core-shell structure with mRNA-containing inner core surrounded by PEG layer, providing the high stability and stealth property to the nanomicelle. The functional polyamino acids possessing the capacity of pH-responsive membrane destabilization allows smooth endosomal escape of the nanomicelle into the cytoplasm. After introduction into CNS, the nanomicelle successfully provided the sustained protein expression in the cerebrospinal fluid for almost a week. Immune responses after mRNA administration into CNS were effectively suppressed by the use of the nanomicelle compared with naked mRNA introduction. In vitro analyses using specific TLR-expressing HEK293 cells confirmed that the nanomicelle inclusion prevented mRNA from the recognition by TLRs. Thus, the polyplex nanomicelle is a promising system that simultaneously resolved the two major problems of in vivo mRNA introduction, the instability and immunogenicity, opening the door to various new therapeutic strategies using mRNA.
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Affiliation(s)
- Satoshi Uchida
- Division of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Keiji Itaka
- Division of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (KI); (KK)
| | - Hirokuni Uchida
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kentaro Hayakawa
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for the Persons With Disabilities, Tokorozawa, Saitama, Japan
| | - Toru Ogata
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for the Persons With Disabilities, Tokorozawa, Saitama, Japan
| | - Takehiko Ishii
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shigeto Fukushima
- Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kensuke Osada
- Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kazunori Kataoka
- Division of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (KI); (KK)
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1011
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Peterson CW, Younan P, Jerome KR, Kiem HP. Combinatorial anti-HIV gene therapy: using a multipronged approach to reach beyond HAART. Gene Ther 2013; 20:695-702. [PMID: 23364313 DOI: 10.1038/gt.2012.98] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/19/2012] [Accepted: 11/22/2012] [Indexed: 12/11/2022]
Abstract
The 'Berlin Patient', who maintains suppressed levels of HIV viremia in the absence of antiretroviral therapy, continues to be a standard bearer in HIV eradication research. However, the unique circumstances surrounding his functional cure are not applicable to most HIV(+) patients. To achieve a functional or sterilizing cure in a greater number of infected individuals worldwide, combinatorial treatments, targeting multiple stages of the viral life cycle, will be essential. Several anti-HIV gene therapy approaches have been explored recently, including disruption of the C-C chemokine receptor 5 (CCR5) and CXC chemokine receptor 4 (CXCR4) coreceptor loci in CD4(+) T cells and CD34(+) hematopoietic stem cells. However, less is known about the efficacy of these strategies in patients and more relevant HIV model systems such as non-human primates (NHPs). Combinatorial approaches, including genetic disruption of integrated provirus, functional enhancement of endogenous restriction factors and/or the use of pharmacological adjuvants, could amplify the anti-HIV effects of CCR5/CXCR4 gene disruption. Importantly, delivering gene disruption molecules to genetic sites of interest will likely require optimization on a cell type-by-cell type basis. In this review, we highlight the most promising gene therapy approaches to combat HIV infection, methods to deliver these therapies to hematopoietic cells and emphasize the need to target viral replication pre- and post-entry to mount a suitably robust defense against spreading infection.
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Affiliation(s)
- C W Peterson
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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1012
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Pan T. N6-methyl-adenosine modification in messenger and long non-coding RNA. Trends Biochem Sci 2013; 38:204-9. [PMID: 23337769 DOI: 10.1016/j.tibs.2012.12.006] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/13/2012] [Accepted: 12/21/2012] [Indexed: 01/09/2023]
Abstract
N6-methyl-adenosine (m(6)A) is the most abundant modification in mammalian mRNA and long non-coding RNA. First discovered in the 1970s, m(6)A modification has been proposed to function in mRNA splicing, export, stability, and immune tolerance. Interest and excitement in m(6)A modification has recently been revived based on the discovery of a mammalian enzyme that removes m(6)A and the application of deep sequencing to localize modification sites. The m(6)A demethylase fat mass and obesity associated protein (FTO) controls cellular energy homeostasis and is the first enzyme discovered that reverses an RNA modification. m(6)A Sequencing demonstrates cell-type- and cell-state-dependent m(6)A patterns, indicating that m(6)A modifications are highly regulated. This review describes the current knowledge of mammalian m(6)A modifications and future perspectives on how to push the field forward.
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Affiliation(s)
- Tao Pan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.
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1013
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Transfection efficiency and transgene expression kinetics of mRNA delivered in naked and nanoparticle format. J Control Release 2013; 166:227-33. [PMID: 23306021 DOI: 10.1016/j.jconrel.2012.12.029] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/26/2012] [Accepted: 12/28/2012] [Indexed: 11/23/2022]
Abstract
Transfection efficiencies and transgene expression kinetics of messenger RNA (mRNA), an emerging class of nucleic acid-based therapeutics, have been poorly characterized. In this study, we evaluated transfection efficiencies of mRNA delivered in naked and nanoparticle format in vitro and in vivo using GFP and luciferase as reporters. While mRNA nanoparticles transfect primary human and mouse dendritic cells (DCs) efficiently in vitro, naked mRNA could not produce any detectable gene product. The protein expression of nanoparticle-mediated transfection in vitro peaks rapidly within 5-7h and decays in a biphasic manner. In vivo, naked mRNA is more efficient than mRNA nanoparticles when administered subcutaneously. In contrast, mRNA nanoparticle performs better when administered intranasally and intravenously. Gene expression is most transient when delivered intravenously in nanoparticle format with an apparent half-life of 1.4h and lasts less than 24h, and most sustained when delivered in the naked format subcutaneously at the base of tail with an apparent half-life of 18h and persists for at least 6days. Notably, exponential decreases in protein expression are consistently observed post-delivery of mRNA in vivo regardless of the mode of delivery (naked or nanoparticle) or the site of administration. This study elucidates the performance of mRNA transfection and suggests a niche for mRNA therapeutics when predictable in vivo transgene expression kinetics is imperative.
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1014
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Pardi N, Muramatsu H, Weissman D, Karikó K. In vitro transcription of long RNA containing modified nucleosides. Methods Mol Biol 2013; 969:29-42. [PMID: 23296925 DOI: 10.1007/978-1-62703-260-5_2] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The in vitro synthesis of long RNA can be accomplished using phage RNA polymerase and template DNA. However, the in vitro synthesized RNA, unlike those transcribed in vivo in cells, lacks nucleoside modifications. Introducing modified nucleosides into in vitro transcripts is important because they reduce the potential of RNA to activate RNA sensors and translation of such nucleoside-modified RNA is increased in cell lines, primary cells, and after in vivo delivery. Here, we describe the in vitro synthesis of nucleoside-modified RNA with enhanced translational capacity and reduced ability to activate immune sensors.
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Affiliation(s)
- Norbert Pardi
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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1015
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Abstract
In vitro transcription of DNA with phage RNA polymerases is currently the most efficient method to produce long sequence-specific RNA. While the reaction can yield large quantities of RNA, it contains impurities due to various unwanted activities of the polymerases. Here, we described an easily performed HPLC purification that removes multiple contaminants from in vitro transcribed RNA and is scalable. The purified RNA is translated at much greater levels, especially in primary cells and in vivo. HPLC purification of RNA containing modified nucleosides that suppress RNA-mediated activation of innate immune sensors leads to a non-immunogenic RNA with superior translational capacity.
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1016
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Abstract
Appropriate gene delivery systems are essential for successful gene therapy in clinical medicine. Cationic lipid-mediated delivery is an alternative to viral vector-mediated gene delivery where transient gene expression is desirable. However, cationic lipid-mediated delivery of DNA to post-mitotic cells is often of low efficiency, due to the difficulty of DNA translocation to the nucleus. Rapid lipid-mediated delivery of RNA is preferable to nonviral DNA delivery in some clinical applications, because transit across the nuclear membrane is not necessary. Here we describe techniques for cationic lipid-mediated delivery of RNA encoding reporter genes in a variety of in vitro cell lines and in vivo. We describe optimized formulations and transfection procedures that we have previously assessed by flow cytometry. RNA transfection demonstrates increased efficiency relative to DNA transfection in nondividing cells. Delivery of mRNA results in onset of expression within 1 h after transfection and a peak in expression 5-7 h after transfection. These results are consistent with our in vivo delivery results, techniques for which are shown as well. Longer duration and the higher mean levels of expression per cell that are ultimately obtained following DNA delivery confirm a continuing role for DNA gene delivery in clinical applications that require long term transient gene expression. RNA delivery is suitable for short-term transient gene expression due to its rapid onset, short duration of expression, and greater efficiency, particularly in nondividing cells.
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Affiliation(s)
- James G Hecker
- Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA, USA.
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1017
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Design and Application of Synthetic Biology Devices for Therapy. Synth Biol (Oxf) 2013. [DOI: 10.1016/b978-0-12-394430-6.00009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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1018
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Schlake T, Thess A, Fotin-Mleczek M, Kallen KJ. Developing mRNA-vaccine technologies. RNA Biol 2012; 9:1319-30. [PMID: 23064118 DOI: 10.4161/rna.22269] [Citation(s) in RCA: 365] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
mRNA vaccines combine desirable immunological properties with an outstanding safety profile and the unmet flexibility of genetic vaccines. Based on in situ protein expression, mRNA vaccines are capable of inducing a balanced immune response comprising both cellular and humoral immunity while not subject to MHC haplotype restriction. In addition, mRNA is an intrinsically safe vector as it is a minimal and only transient carrier of information that does not interact with the genome. Because any protein can be expressed from mRNA without the need to adjust the production process, mRNA vaccines also offer maximum flexibility with respect to development. Taken together, mRNA presents a promising vector that may well become the basis of a game-changing vaccine technology platform. Here, we outline the current knowledge regarding different aspects that should be considered when developing an mRNA-based vaccine technology.
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1019
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Increased erythropoiesis in mice injected with submicrogram quantities of pseudouridine-containing mRNA encoding erythropoietin. Mol Ther 2012; 20:948-53. [PMID: 22334017 PMCID: PMC3345990 DOI: 10.1038/mt.2012.7] [Citation(s) in RCA: 210] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Advances in the optimization of in vitro-transcribed mRNA are bringing mRNA-mediated therapy closer to reality. In cultured cells, we recently achieved high levels of translation with high-performance liquid chromatography (HPLC)-purified, in vitro-transcribed mRNAs containing the modified nucleoside pseudouridine. Importantly, pseudouridine rendered the mRNA non-immunogenic. Here, using erythropoietin (EPO)-encoding mRNA complexed with TransIT-mRNA, we evaluated this new generation of mRNA in vivo. A single injection of 100 ng (0.005 mg/kg) mRNA elevated serum EPO levels in mice significantly by 6 hours and levels were maintained for 4 days. In comparison, mRNA containing uridine produced 10–100-fold lower levels of EPO lasting only 1 day. EPO translated from pseudouridine-mRNA was functional and caused a significant increase of both reticulocyte counts and hematocrits. As little as 10 ng mRNA doubled reticulocyte numbers. Weekly injection of 100 ng of EPO mRNA was sufficient to increase the hematocrit from 43 to 57%, which was maintained with continued treatment. Even when a large amount of pseudouridine-mRNA was injected, no inflammatory cytokines were detectable in plasma. Using macaques, we could also detect significantly-increased serum EPO levels following intraperitoneal injection of rhesus EPO mRNA. These results demonstrate that HPLC-purified, pseudouridine-containing mRNAs encoding therapeutic proteins have great potential for clinical applications.
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1020
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Abstract
Nucleofection permits efficient transfection even with difficult cell types such as primary and non-dividing cells, and is used to deliver various nucleic acids including DNA, mRNA, and siRNA. Unlike DNA and siRNA, mRNA is subject to rapid degradation, which necessitates instant early translation following mRNA delivery. We examined factors important in translation following nucleofection and observed rapid phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α) following nucleofection, which occurred in the absence of delivered nucleic acid. We studied the involvement of 3 ubiquitous kinases capable of phosphorylating eIF2α in mammalian cells and identified that nucleofection-mediated phosphorylation of eIF2α was dependent on general control non-derepressible 2 (GCN2) and protein kinase RNA-activated (PKR)-like ER kinase (PERK) but not PKR. A reduction in translation due to eIF2α phosphorylation was observed post nucleofection demonstrating functional significance. Understanding the impact of nucleofection on translational machinery has important implications for therapeutics currently under development based on the delivery of mRNA, DNA, and siRNA. Strategies to circumvent eIF2α phosphorylation and other downstream effects of activating GCN2 and PERK will facilitate further advancement of nucleic acid-based therapies.
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1021
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Sohn YD, Han JW, Yoon YS. Generation of induced pluripotent stem cells from somatic cells. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 111:1-26. [PMID: 22917224 DOI: 10.1016/b978-0-12-398459-3.00001-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The technology for generation of induced pluripotent stem cell (iPSC) from somatic cells emerged to circumvent the ethical and immunological limitations of embryonic stem cell (ESC). The recent progress of iPSC technology offers an unprecedented tool for regenerative medicine; however, integrating viral-driven iPSCs prohibits clinical applications by their genetic alterations and tumorigenicity. Various approaches including nonintegrating, nonviral, and nongenetic methods have been developed for generating clinically compatible iPSCs. In addition, approaches for using more clinically convenient or compatible source cells replacing fibroblasts have been actively pursued. While iPSC and ESC closely resemble in genomic, cell biologic, and phenotypic characteristics, these two pluripotent stem cells are not identical in terms of differentiation capacity and epigenetic features. In this chapter, we deal with the current techniques of generating iPSCs and their various characteristics.
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Affiliation(s)
- Young-Doug Sohn
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA
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1022
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Karikó K, Muramatsu H, Ludwig J, Weissman D. Generating the optimal mRNA for therapy: HPLC purification eliminates immune activation and improves translation of nucleoside-modified, protein-encoding mRNA. Nucleic Acids Res 2011; 39:e142. [PMID: 21890902 PMCID: PMC3241667 DOI: 10.1093/nar/gkr695] [Citation(s) in RCA: 547] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In vitro-transcribed mRNA has great therapeutic potential to transiently express the encoded protein without the adverse effects of viral and DNA-based constructs. Mammalian cells, however, contain RNA sensors of the innate immune system that must be considered in the generation of therapeutic RNA. Incorporation of modified nucleosides both reduces innate immune activation and increases translation of mRNA, but residual induction of type I interferons (IFNs) and proinflammatory cytokines remains. We identify that contaminants, including double-stranded RNA, in nucleoside-modified in vitro-transcribed RNA are responsible for innate immune activation and their removal by high performance liquid chromatography (HPLC) results in mRNA that does not induce IFNs and inflammatory cytokines and is translated at 10- to 1000-fold greater levels in primary cells. Although unmodified mRNAs were translated significantly better following purification, they still induced high levels of cytokine secretion. HPLC purified nucleoside-modified mRNA is a powerful vector for applications ranging from ex vivo stem cell generation to in vivo gene therapy.
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Affiliation(s)
- Katalin Karikó
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA, Institute of Clinical Chemistry and Pharmacology, University of Bonn, Bonn, Germany and Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hiromi Muramatsu
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA, Institute of Clinical Chemistry and Pharmacology, University of Bonn, Bonn, Germany and Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - János Ludwig
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA, Institute of Clinical Chemistry and Pharmacology, University of Bonn, Bonn, Germany and Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Drew Weissman
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA, Institute of Clinical Chemistry and Pharmacology, University of Bonn, Bonn, Germany and Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- *To whom correspondence should be addressed. Tel: +1 215 573 8491; Fax: +215 349 5111;
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1023
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Anderson BR, Muramatsu H, Jha BK, Silverman RH, Weissman D, Karikó K. Nucleoside modifications in RNA limit activation of 2'-5'-oligoadenylate synthetase and increase resistance to cleavage by RNase L. Nucleic Acids Res 2011; 39:9329-38. [PMID: 21813458 PMCID: PMC3241635 DOI: 10.1093/nar/gkr586] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The interferon-induced enzymes 2′-5′-oligoadenylate synthetase (OAS) and RNase L are key components of innate immunity involved in sensory and effector functions following viral infections. Upon binding target RNA, OAS is activated to produce 2′-5′-linked oligoadenylates (2-5A) that activate RNase L, which then cleaves single-stranded self and non-self RNA. Modified nucleosides that are present in cellular transcripts have been shown to suppress activation of several RNA sensors. Here, we demonstrate that in vitro transcribed, unmodified RNA activates OAS, induces RNase L-mediated ribosomal RNA (rRNA) cleavage and is rapidly cleaved by RNase L. In contrast, RNA containing modified nucleosides activates OAS less efficiently and induces limited rRNA cleavage. Nucleoside modifications also make RNA resistant to cleavage by RNase L. Examining translation in RNase L−/− cells and mice confirmed that RNase L activity reduces translation of unmodified mRNA, which is not observed with modified mRNA. Additionally, mRNA containing the nucleoside modification pseudouridine is translated longer and has an extended half-life. The observation that modified nucleosides in RNA reduce 2-5A pathway activation joins OAS and RNase L to the list of RNA sensors and effectors whose functions are limited when RNA is modified, confirming the role of nucleoside modifications in suppressing immune recognition of RNA.
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Affiliation(s)
- Bart R Anderson
- Department of Medicine, 3610 Hamilton Walk, 522B Johnson Pavilion, University of Pennsylvania, Philadelphia, PA 19104, USA
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1024
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Highly efficient reprogramming to pluripotency and directed differentiation of human cells with synthetic modified mRNA. Cell Stem Cell 2010; 7:618-30. [PMID: 20888316 DOI: 10.1016/j.stem.2010.08.012] [Citation(s) in RCA: 1854] [Impact Index Per Article: 132.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 05/11/2010] [Accepted: 08/11/2010] [Indexed: 11/21/2022]
Abstract
Clinical application of induced pluripotent stem cells (iPSCs) is limited by the low efficiency of iPSC derivation and the fact that most protocols modify the genome to effect cellular reprogramming. Moreover, safe and effective means of directing the fate of patient-specific iPSCs toward clinically useful cell types are lacking. Here we describe a simple, nonintegrating strategy for reprogramming cell fate based on administration of synthetic mRNA modified to overcome innate antiviral responses. We show that this approach can reprogram multiple human cell types to pluripotency with efficiencies that greatly surpass established protocols. We further show that the same technology can be used to efficiently direct the differentiation of RNA-induced pluripotent stem cells (RiPSCs) into terminally differentiated myogenic cells. This technology represents a safe, efficient strategy for somatic cell reprogramming and directing cell fate that has broad applicability for basic research, disease modeling, and regenerative medicine.
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1025
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Anderson BR, Muramatsu H, Nallagatla SR, Bevilacqua PC, Sansing LH, Weissman D, Karikó K. Incorporation of pseudouridine into mRNA enhances translation by diminishing PKR activation. Nucleic Acids Res 2010; 38:5884-92. [PMID: 20457754 PMCID: PMC2943593 DOI: 10.1093/nar/gkq347] [Citation(s) in RCA: 351] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Previous studies have shown that the translation level of in vitro transcribed messenger RNA (mRNA) is enhanced when its uridines are replaced with pseudouridines; however, the reason for this enhancement has not been identified. Here, we demonstrate that in vitro transcripts containing uridine activate RNA-dependent protein kinase (PKR), which then phosphorylates translation initiation factor 2-alpha (eIF-2α), and inhibits translation. In contrast, in vitro transcribed mRNAs containing pseudouridine activate PKR to a lesser degree, and translation of pseudouridine-containing mRNAs is not repressed. RNA pull-down assays demonstrate that mRNA containing uridine is bound by PKR more efficiently than mRNA with pseudouridine. Finally, the role of PKR is validated by showing that pseudouridine- and uridine-containing RNAs were translated equally in PKR knockout cells. These results indicate that the enhanced translation of mRNAs containing pseudouridine, compared to those containing uridine, is mediated by decreased activation of PKR.
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Affiliation(s)
- Bart R Anderson
- Department of Medicine, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
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1026
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Strenkowska M, Kowalska J, Lukaszewicz M, Zuberek J, Su W, Rhoads RE, Darzynkiewicz E, Jemielity J. Towards mRNA with superior translational activity: synthesis and properties of ARCA tetraphosphates with single phosphorothioate modifications. NEW J CHEM 2010; 34:993-1007. [PMID: 20711517 PMCID: PMC2918917 DOI: 10.1039/b9nj00644c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We describe the chemical synthesis and preliminary biophysical and biochemical characterization of a series of mRNA 5' end (cap) analogs designed as reagents for obtaining mRNA molecules with augmented translation efficiency and stability in vivo and as useful tools to study mRNA metabolism. The analogs share three structural features: (i) 5',5'- bridge elongated to tetraphosphate to increase their affinity to translation initiation factor eIF4E (ii) a single phosphorothioate modification at either the α, β, γ or δ-position of the tetraphosphate to decrease their susceptibility to enzymatic degradation and/or to modulate their interaction with specific proteins and (iii) a 2'-O-methyl group in the ribose of 7-methylguanosine, characteristic to Anti-Reverse Cap Analogs (ARCAs), which are incorporated into mRNA during in vitro transcription exclusively in the correct orientation. The dinucleotides bearing modified tetraphosphate bridge were synthesized by ZnCl(2) mediated coupling between two mononucleotide subunits with isolated yields of 30-65%. The preliminary biochemical results show that mRNAs capped with new analogs are 2.5-4.5 more efficiently translated in a cell free system than m(7)GpppG-capped mRNAs, which makes them promising candidates for RNA-based therapeutic applications such as gene therapy and anti-cancer vaccines.
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Affiliation(s)
- Malwina Strenkowska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
| | - Maciej Lukaszewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
| | - Joanna Zuberek
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
| | - Wei Su
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA 71130-3932, USA
| | - Robert E. Rhoads
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA 71130-3932, USA
| | - Edward Darzynkiewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
| | - Jacek Jemielity
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland. Fax: 48 22 5540771; Tel: 48 22 5540774
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1027
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Jemielity J, Kowalska J, Rydzik AM, Darzynkiewicz E. Synthetic mRNA cap analogs with a modified triphosphate bridge – synthesis, applications and prospects. NEW J CHEM 2010. [DOI: 10.1039/c0nj00041h] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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