1
|
Liu P, Ponnienselvan K, Nyalile T, Oikemus S, Joynt AT, Iyer S, Kelly K, Guo D, Kyawe PP, Vanderleeden E, Redick SD, Huang L, Chen Z, Lee JM, Schiffer CA, Harlan DM, Wang JP, Emerson CP, Lawson ND, Watts JK, Sontheimer EJ, Luban J, Wolfe SA. Increasing intracellular dNTP levels improves prime editing efficiency. Nat Biotechnol 2024:10.1038/s41587-024-02405-x. [PMID: 39322763 DOI: 10.1038/s41587-024-02405-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 08/27/2024] [Indexed: 09/27/2024]
Abstract
In primary cell types, intracellular deoxynucleotide triphosphate (dNTP) levels are tightly regulated in a cell cycle-dependent manner. We report that prime editing efficiency is increased by mutations that improve the enzymatic properties of Moloney murine leukemia virus reverse transcriptase and treatments that increase intracellular dNTP levels. In combination, these modifications produce substantial increases in precise editing rates.
Collapse
Affiliation(s)
- Pengpeng Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Karthikeyan Ponnienselvan
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Thomas Nyalile
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Sarah Oikemus
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Anya T Joynt
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Sukanya Iyer
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Karen Kelly
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Dongsheng Guo
- Department of Neurology, Wellstone Program, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Pyae P Kyawe
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Emma Vanderleeden
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Sambra D Redick
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Lei Huang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Zexiang Chen
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jeong Min Lee
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - David M Harlan
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jennifer P Wang
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Charles P Emerson
- Department of Neurology, Wellstone Program, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Nathan D Lawson
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jonathan K Watts
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Erik J Sontheimer
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jeremy Luban
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Scot A Wolfe
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, USA.
| |
Collapse
|
2
|
Liu H, Hu K, O’Connor K, Kelliher MA, Zhu LJ. CleanUpRNAseq: An R/Bioconductor Package for Detecting and Correcting DNA Contamination in RNA-Seq Data. BIOTECH 2024; 13:30. [PMID: 39189209 PMCID: PMC11348166 DOI: 10.3390/biotech13030030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/01/2024] [Accepted: 07/14/2024] [Indexed: 08/28/2024] Open
Abstract
RNA sequencing (RNA-seq) has become a standard method for profiling gene expression, yet genomic DNA (gDNA) contamination carried over to the sequencing library poses a significant challenge to data integrity. Detecting and correcting this contamination is vital for accurate downstream analyses. Particularly, when RNA samples are scarce and invaluable, it becomes essential not only to identify but also to correct gDNA contamination to maximize the data's utility. However, existing tools capable of correcting gDNA contamination are limited and lack thorough evaluation. To fill the gap, we developed CleanUpRNAseq, which offers a comprehensive set of functionalities for identifying and correcting gDNA-contaminated RNA-seq data. Our package offers three correction methods for unstranded RNA-seq data and a dedicated approach for stranded data. Through rigorous validation on published RNA-seq datasets with known levels of gDNA contamination and real-world RNA-seq data, we demonstrate CleanUpRNAseq's efficacy in detecting and correcting detrimental levels of gDNA contamination across diverse library protocols. CleanUpRNAseq thus serves as a valuable tool for post-alignment quality assessment of RNA-seq data and should be integrated into routine workflows for RNA-seq data analysis. Its incorporation into OneStopRNAseq should significantly bolster the accuracy of gene expression quantification and differential expression analysis of RNA-seq data.
Collapse
Affiliation(s)
- Haibo Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; (H.L.); (K.H.); (M.A.K.)
| | - Kai Hu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; (H.L.); (K.H.); (M.A.K.)
| | - Kevin O’Connor
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; (H.L.); (K.H.); (M.A.K.)
| | - Michelle A. Kelliher
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; (H.L.); (K.H.); (M.A.K.)
| | - Lihua Julie Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA; (H.L.); (K.H.); (M.A.K.)
- Department of Molecular Medicine, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
- Department of Genomics and Computational Biology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| |
Collapse
|
3
|
Wu MJ, Kondo H, Kammula AV, Shi L, Xiao Y, Dhiab S, Xu Q, Slater CJ, Avila OI, Merritt J, Kato H, Kattel P, Sussman J, Gritti I, Eccleston J, Sun Y, Cho HM, Olander K, Katsuda T, Shi DD, Savani MR, Smith BC, Cleary JM, Mostoslavsky R, Vijay V, Kitagawa Y, Wakimoto H, Jenkins RW, Yates KB, Paik J, Tassinari A, Saatcioglu DH, Tron AE, Haas W, Cahill D, McBrayer SK, Manguso RT, Bardeesy N. Mutant IDH1 inhibition induces dsDNA sensing to activate tumor immunity. Science 2024; 385:eadl6173. [PMID: 38991060 DOI: 10.1126/science.adl6173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/09/2024] [Indexed: 07/13/2024]
Abstract
Isocitrate dehydrogenase 1 (IDH1) is the most commonly mutated metabolic gene across human cancers. Mutant IDH1 (mIDH1) generates the oncometabolite (R)-2-hydroxyglutarate, disrupting enzymes involved in epigenetics and other processes. A hallmark of IDH1-mutant solid tumors is T cell exclusion, whereas mIDH1 inhibition in preclinical models restores antitumor immunity. Here, we define a cell-autonomous mechanism of mIDH1-driven immune evasion. IDH1-mutant solid tumors show selective hypermethylation and silencing of the cytoplasmic double-stranded DNA (dsDNA) sensor CGAS, compromising innate immune signaling. mIDH1 inhibition restores DNA demethylation, derepressing CGAS and transposable element (TE) subclasses. dsDNA produced by TE-reverse transcriptase (TE-RT) activates cGAS, triggering viral mimicry and stimulating antitumor immunity. In summary, we demonstrate that mIDH1 epigenetically suppresses innate immunity and link endogenous RT activity to the mechanism of action of a US Food and Drug Administration-approved oncology drug.
Collapse
Affiliation(s)
- Meng-Ju Wu
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Hiroshi Kondo
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Ashwin V Kammula
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Lei Shi
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Yi Xiao
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sofiene Dhiab
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Qin Xu
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Chloe J Slater
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Universite Paris-Saclay, Institut Gustave Roussy, INSERM U1015, Villejuif, France
- Servier Pharmaceuticals LLC, Boston, MA, USA
| | - Omar I Avila
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Joshua Merritt
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Hiroyuki Kato
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Prabhat Kattel
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Jonathan Sussman
- Abramson Family Cancer Research Institute and Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Graduate Group in Genomics and Computational Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Ilaria Gritti
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Jason Eccleston
- Abramson Family Cancer Research Institute and Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Yi Sun
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
| | - Hyo Min Cho
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Kira Olander
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Takeshi Katsuda
- Abramson Family Cancer Research Institute and Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Diana D Shi
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, USA
| | - Milan R Savani
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Medical Scientist Training Program, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bailey C Smith
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Raul Mostoslavsky
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Vindhya Vijay
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Yosuke Kitagawa
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Hiroaki Wakimoto
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Russell W Jenkins
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
- Laboratory of Systems Pharmacology, Harvard Program in Therapeutic Sciences, Harvard Medical School, Boston, MA, USA
| | - Kathleen B Yates
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Jihye Paik
- Department of Pathology and Laboratory Medicine, Sandra and Edward Meyer Cancer Center, Weill Medical College of Cornell University, New York, NY, USA
| | | | | | | | - Wilhelm Haas
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Daniel Cahill
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Samuel K McBrayer
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Robert T Manguso
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Nabeel Bardeesy
- Krantz Family Center for Cancer Research, Massachusetts General Hospital, Boston MA, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| |
Collapse
|
4
|
Shuto Y, Nakagawa R, Zhu S, Hoki M, Omura SN, Hirano H, Itoh Y, Zhang F, Nureki O. Structural basis for pegRNA-guided reverse transcription by a prime editor. Nature 2024; 631:224-231. [PMID: 38811740 PMCID: PMC11222144 DOI: 10.1038/s41586-024-07497-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 04/30/2024] [Indexed: 05/31/2024]
Abstract
The prime editor system composed of Streptococcus pyogenes Cas9 nickase (nSpCas9) and engineered Moloney murine leukaemia virus reverse transcriptase (M-MLV RT) collaborates with a prime editing guide RNA (pegRNA) to facilitate a wide variety of precise genome edits in living cells1. However, owing to a lack of structural information, the molecular mechanism of pegRNA-guided reverse transcription by the prime editor remains poorly understood. Here we present cryo-electron microscopy structures of the SpCas9-M-MLV RTΔRNaseH-pegRNA-target DNA complex in multiple states. The termination structure, along with our functional analysis, reveals that M-MLV RT extends reverse transcription beyond the expected site, resulting in scaffold-derived incorporations that cause undesired edits at the target loci. Furthermore, structural comparisons among the pre-initiation, initiation and elongation states show that M-MLV RT remains in a consistent position relative to SpCas9 during reverse transcription, whereas the pegRNA-synthesized DNA heteroduplex builds up along the surface of SpCas9. On the basis of our structural insights, we rationally engineered pegRNA variants and prime-editor variants in which M-MLV RT is fused within SpCas9. Collectively, our findings provide structural insights into the stepwise mechanism of prime editing, and will pave the way for the development of a versatile prime editing toolbox.
Collapse
Affiliation(s)
- Yutaro Shuto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Ryoya Nakagawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| | - Shiyou Zhu
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mizuki Hoki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi N Omura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hisato Hirano
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuzuru Itoh
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Feng Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| |
Collapse
|
5
|
Hardy J, Demecheleer E, Schauvliege M, Staelens D, Mortier V, Verhofstede C. Reverse transcription of plasma-derived HIV-1 RNA generates multiple artifacts through tRNA(Lys-3)-priming. Microbiol Spectr 2024; 12:e0387223. [PMID: 38442427 PMCID: PMC10986323 DOI: 10.1128/spectrum.03872-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/05/2024] [Indexed: 03/07/2024] Open
Abstract
In vitro reverse transcription of full-length HIV-1 RNA extracted from the blood plasma of people living with HIV-1 remains challenging. Here, we describe the initiation of reverse transcription of plasma-derived viral RNA in the absence of an exogenous primer. Real-time PCR and Sanger sequencing were applied to identify the source and to monitor the outcome of this reaction. Results demonstrated that during purification of viral RNA from plasma, tRNA(Lys-3) is co-extracted in a complex with the viral RNA. In the presence of a reverse transcription enzyme, this tRNA(Lys-3) can induce reverse transcription, a reaction that is not confined to transcription of the 5' end of the viral RNA. A range of cDNA products is generated, most of them indicative for the occurrence of in vitro strand transfer events that involve translocation of cDNA from the 5' end to random positions on the viral RNA. This process results in the formation of cDNAs with large internal deletions. However, near full-length cDNA and cDNA with sequence patterns resembling multiple spliced HIV-1 RNA were also detected. Despite its potential to introduce significant bias in the interpretation of results across various applications, tRNA(Lys-3)-driven reverse transcription has been overlooked thus far. A more in-depth study of this tRNA-driven in vitro reaction may provide new insight into the complex process of in vivo HIV-1 replication.IMPORTANCEThe use of silica-based extraction methods for purifying HIV-1 RNA from viral particles is a common practice, but it involves co-extraction of human tRNA(Lys-3) due to the strong interactions between these molecules. This co-extraction becomes particularly significant when the extracted RNA is used in reverse transcription reactions, as the tRNA(Lys-3) then serves as a primer. Reverse transcription from tRNA(Lys-3) is not confined to cDNA synthesis of the 5' end of the viral RNA but extends across various regions of the viral genome through in vitro strand transfer events. Co-extraction of tRNA(Lys-3) has been overlooked thus far, despite its potential to introduce bias in downstream, reverse transcription-related applications. The observed events in the tRNA(Lys-3)-induced in vitro reverse transcription resemble in vivo replication processes. Therefore, these reactions may offer a unique model to better understand the replication dynamics of HIV-1.
Collapse
Affiliation(s)
- Jarryt Hardy
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Els Demecheleer
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Marlies Schauvliege
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Delfien Staelens
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Virginie Mortier
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Chris Verhofstede
- Aids Reference Laboratory, Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| |
Collapse
|
6
|
Su Q, Wang J, Kang K, Niu Y, Li S, Gou D. Critical view on oligo(dT)-based RNA-seq: bias arising, modeling, and mitigating. Genetics 2024; 226:iyad190. [PMID: 37857456 DOI: 10.1093/genetics/iyad190] [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: 09/05/2023] [Revised: 10/12/2023] [Accepted: 10/15/2023] [Indexed: 10/21/2023] Open
Abstract
The precise biological interpretation of oligo(dT)-based RNA sequencing (RNA-seq) datasets, particularly in single-cell RNA-seq (scRNA-seq), is invaluable for understanding complex biological systems. However, the presence of biases can lead to misleading results in downstream analysis. This study has now identified two additional biases that are not accounted for in established bias models: poly(A)-tail length bias and fixed-position GC-content bias. These biases have a significant negative impact on the overall quality of oligo(dT)-based RNA-seq data. To address these biases, we have developed a universal bias-mitigating method based on the lower-affinity binding of short and nonanchored oligo(dT) primers to poly(A) tails. This method significantly reduces poly(A) length bias and completely eliminates fixed-position GC bias. Furthermore, the use of short oligo(dT) with impartial binding behavior toward the diverse poly(A) tails renders RNA-seq with more reliable measurements. The findings of this study are particularly beneficial for scRNA-seq datasets, where accurate benchmarking is critical.
Collapse
Affiliation(s)
- Qiang Su
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Jun Wang
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Kang Kang
- Department of Biochemistry and Molecular Biology, Guangdong Provincial Key Laboratory of Regional Immunity and Diseases, Carson International Cancer Center, Shenzhen University Health Sciences Center, Shenzhen, Guangdong 518060, China
| | - Yanqin Niu
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Shujin Li
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Deming Gou
- Shenzhen Key Laboratory of Microbial Genetic Engineering, Vascular Disease Research Center, College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory of Regional Immunity and Disease, Shenzhen University, Shenzhen, Guangdong 518055, China
| |
Collapse
|
7
|
Xiao Y, Chen YM, Zou Z, Ye C, Dou X, Wu J, Liu C, Liu S, Yan H, Wang P, Zeng TB, Liu Q, Fei J, Tang W, He C. Profiling of RNA-binding protein binding sites by in situ reverse transcription-based sequencing. Nat Methods 2024; 21:247-258. [PMID: 38200227 PMCID: PMC10864177 DOI: 10.1038/s41592-023-02146-w] [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: 03/05/2023] [Accepted: 12/07/2023] [Indexed: 01/12/2024]
Abstract
RNA-binding proteins (RBPs) regulate diverse cellular processes by dynamically interacting with RNA targets. However, effective methods to capture both stable and transient interactions between RBPs and their RNA targets are still lacking, especially when the interaction is dynamic or samples are limited. Here we present an assay of reverse transcription-based RBP binding site sequencing (ARTR-seq), which relies on in situ reverse transcription of RBP-bound RNAs guided by antibodies to identify RBP binding sites. ARTR-seq avoids ultraviolet crosslinking and immunoprecipitation, allowing for efficient and specific identification of RBP binding sites from as few as 20 cells or a tissue section. Taking advantage of rapid formaldehyde fixation, ARTR-seq enables capturing the dynamic RNA binding by RBPs over a short period of time, as demonstrated by the profiling of dynamic RNA binding of G3BP1 during stress granule assembly on a timescale as short as 10 minutes.
Collapse
Affiliation(s)
- Yu Xiao
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Yan-Ming Chen
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Zhongyu Zou
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Chang Ye
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Xiaoyang Dou
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Jinjun Wu
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Chang Liu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Shun Liu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Hao Yan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Pingluan Wang
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Tie-Bo Zeng
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Qinzhe Liu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, Chicago, IL, USA
| | - Jingyi Fei
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Weixin Tang
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Chuan He
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
- Howard Hughes Medical Institute, Chicago, IL, USA.
| |
Collapse
|
8
|
Vu TV, Nguyen NT, Kim J, Hong JC, Kim J. Prime editing: Mechanism insight and recent applications in plants. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:19-36. [PMID: 37794706 PMCID: PMC10754014 DOI: 10.1111/pbi.14188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/14/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023]
Abstract
Prime editing (PE) technology utilizes an extended prime editing guide RNA (pegRNA) to direct a fusion peptide consisting of nCas9 (H840) and reverse transcriptase (RT) to a specific location in the genome. This enables the installation of base changes at the targeted site using the extended portion of the pegRNA through RT activity. The resulting product of the RT reaction forms a 3' flap, which can be incorporated into the genomic site through a series of biochemical steps involving DNA repair and synthesis pathways. PE has demonstrated its effectiveness in achieving almost all forms of precise gene editing, such as base conversions (all types), DNA sequence insertions and deletions, chromosomal translocation and inversion and long DNA sequence insertion at safe harbour sites within the genome. In plant science, PE could serve as a groundbreaking tool for precise gene editing, allowing the creation of desired alleles to improve crop varieties. Nevertheless, its application has encountered limitations due to efficiency constraints, particularly in dicotyledonous plants. In this review, we discuss the step-by-step mechanism of PE, shedding light on the critical aspects of each step while suggesting possible solutions to enhance its efficiency. Additionally, we present an overview of recent advancements and future perspectives in PE research specifically focused on plants, examining the key technical considerations of its applications.
Collapse
Affiliation(s)
- Tien V. Vu
- Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuKorea
| | - Ngan Thi Nguyen
- Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuKorea
| | - Jihae Kim
- Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuKorea
| | - Jong Chan Hong
- Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuKorea
| | - Jae‐Yean Kim
- Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuKorea
- Division of Life ScienceGyeongsang National UniversityJinjuKorea
- Nulla Bio Inc.JinjuKorea
| |
Collapse
|
9
|
Ponnienselvan K, Liu P, Nyalile T, Oikemus S, Joynt AT, Kelly K, Guo D, Chen Z, Lee JM, Schiffer CA, Emerson CP, Lawson ND, Watts JK, Sontheimer EJ, Luban J, Wolfe SA. Addressing the dNTP bottleneck restricting prime editing activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.21.563443. [PMID: 37904991 PMCID: PMC10614944 DOI: 10.1101/2023.10.21.563443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Prime editing efficiency is modest in cells that are quiescent or slowly proliferating where intracellular dNTP levels are tightly regulated. MMLV-reverse transcriptase - the prime editor polymerase subunit - requires high intracellular dNTPs levels for efficient polymerization. We report that prime editing efficiency in primary cells and in vivo is increased by mutations that enhance the enzymatic properties of MMLV-reverse transcriptase and can be further complemented by targeting SAMHD1 for degradation.
Collapse
|
10
|
Martínez Del Río J, López-Carrobles N, Mendieta-Moreno JI, Herrera-Chacón Ó, Sánchez-Ibáñez A, Mendieta J, Menéndez-Arias L. Charge Engineering of the Nucleic Acid Binding Cleft of a Thermostable HIV-1 Reverse Transcriptase Reveals Key Interactions and a Novel Mechanism of RNase H Inactivation. J Mol Biol 2023; 435:168219. [PMID: 37536391 DOI: 10.1016/j.jmb.2023.168219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/05/2023]
Abstract
Coupled with PCR, reverse transcriptases (RTs) have been widely used for RNA detection and gene expression analysis. Increased thermostability and nucleic acid binding affinity are desirable RT properties to improve yields and sensitivity of these applications. The effects of amino acid substitutions in the RT RNase H domain were tested in an engineered HIV-1 group O RT, containing mutations K358R/A359G/S360A and devoid of RNase H activity due to the presence of E478Q (O3MQ RT). Twenty mutant RTs with Lys or Arg at positions interacting with the template-primer (i.e., at positions 473-477, 499-502 and 505) were obtained and characterized. Most of them produced significant amounts of cDNA at 37, 50 and 65 °C, as determined in RT-PCR reactions. However, a big loss of activity was observed with mutants A477K/R, S499K/R, V502K/R and Y505K/R, particularly at 65 °C. Binding affinity experiments confirmed that residues 477, 502 and 505 were less tolerant to mutations. Amino acid substitutions Q500K and Q500R produced a slight increase of cDNA synthesis efficiency at 50 and 65 °C, without altering the KD for model DNA/DNA and RNA/DNA heteroduplexes. Interestingly, molecular dynamics simulations predicted that those mutations inactivate the RNase H activity by altering the geometry of the catalytic site. Proof of this unexpected effect was obtained after introducing Q500K or Q500R in the wild-type HIV-1BH10 RT and mutant K358R/A359G/S360A RT. Our results reveal a novel mechanism of RNase H inactivation that preserves RT DNA binding and polymerization efficiency without substituting RNase H active site residues.
Collapse
Affiliation(s)
- Javier Martínez Del Río
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), c/ Nicolás Cabrera 1, Campus de Cantoblanco-UAM, Madrid, Spain
| | - Nerea López-Carrobles
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), c/ Nicolás Cabrera 1, Campus de Cantoblanco-UAM, Madrid, Spain
| | | | - Óscar Herrera-Chacón
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), c/ Nicolás Cabrera 1, Campus de Cantoblanco-UAM, Madrid, Spain
| | - Adrián Sánchez-Ibáñez
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), c/ Nicolás Cabrera 1, Campus de Cantoblanco-UAM, Madrid, Spain
| | - Jesús Mendieta
- Department of Biotechnology, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Luis Menéndez-Arias
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), c/ Nicolás Cabrera 1, Campus de Cantoblanco-UAM, Madrid, Spain.
| |
Collapse
|
11
|
Ni P, Zhao Y, Zhou X, Liu Z, Huang Z, Ni Z, Sun Q, Zong Y. Efficient and versatile multiplex prime editing in hexaploid wheat. Genome Biol 2023; 24:156. [PMID: 37386475 PMCID: PMC10308706 DOI: 10.1186/s13059-023-02990-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 06/15/2023] [Indexed: 07/01/2023] Open
Abstract
Prime editing is limited by low efficiency in plants. Here, we develop an upgraded engineered plant prime editor in hexaploid wheat, ePPEplus, by introducing a V223A substitution into reverse transcriptase in the ePPEmax* architecture. ePPEplus enhances the efficiency by an average 33.0-fold and 6.4-fold compared to the original PPE and ePPE, respectively. Importantly, a robust multiplex prime editing platform is established for simultaneous editing of four to ten genes in protoplasts and up to eight genes in regenerated wheat plants at frequencies up to 74.5%, thus expanding the applicability of prime editors for stacking of multiple agronomic traits.
Collapse
Affiliation(s)
- Pei Ni
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Yidi Zhao
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Ximeng Zhou
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Zehua Liu
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Zhengwei Huang
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Zhongfu Ni
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Qixin Sun
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Yuan Zong
- Frontiers Science Center for Molecular Design Breeding (MOE), Key Laboratory of Crop Heterosis and Utilization (MOE), and Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.
| |
Collapse
|
12
|
Major L, McClements ME, MacLaren RE. New CRISPR Tools to Correct Pathogenic Mutations in Usher Syndrome. Int J Mol Sci 2022; 23:ijms231911669. [PMID: 36232969 PMCID: PMC9569511 DOI: 10.3390/ijms231911669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
Inherited retinal degenerations are a leading cause of blindness in the UK. Significant advances have been made to tackle this issue in recent years, with a pioneering FDA approved gene therapy treatment (Luxturna®), which targets a loss of function mutation in the RPE65 gene. However, there remain notable shortcomings to this form of gene replacement therapy. In particular, the lack of viability for gene sequences exceeding the 4.7 kb adeno-associated virus (AAV) packaging limit or for toxic gain of function mutations. The USH2A gene at ~15.7 kb for instance is too large for AAV delivery: a safe and effective vehicle capable of transducing photoreceptor cells for gene replacement therapy. Usher Syndrome is a clinically and genetically heterogenous deaf-blindness syndrome with autosomal recessive inheritance. The USH2A gene encodes the protein usherin, which localises to the photoreceptor cilium and cochlear hair cells. Mutations in the USH2A gene cause Usher Syndrome type II (USH2), which is the most common subtype of Usher Syndrome and the focus of this review. To date, researchers have been unable to create an efficient, safe editing tool that is small enough to fit inside a single AAV vector for delivery into human cells. This article reviews the potential of CRISPR technology, derived from bacterial defence mechanisms, to overcome these challenges; delivering tools to precisely edit and correct small insertions, deletions and base transitions in USH2A without the need to deliver the full-length gene. Such an ultra-compact therapy could make strides in combating a significant cause of blindness in young people.
Collapse
Affiliation(s)
- Lauren Major
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
| | - Michelle E. McClements
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| |
Collapse
|