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6 results for search term 'crispr' in category Publication
CRISPR-CasĪ¦ from huge phages is a hypercompact genome editor.Publication - [In Vitro] [Genome Editors] [Human]PII: 369/6501/333, PUBMED 32675376, PMC PMC8207990, MID NIHMS1702779, DOI 10.1126/science.abb1400 ABSTRACT: CRISPR-Cas systems are found widely in prokaryotes, where they provide adaptive immunity against virus infection and plasmid transformation. We describe a minimal functional CRISPR-Cas system, comprising a single ~70-kilodalton protein, CasĪ¦, and a CRISPR array, encoded exclusively in the genomes of huge bacteriophages. CasĪ¦ uses a single active site for both CRISPR RNA (crRNA) processing and crRNA-guided DNA cutting to target foreign nucleic acids. This hypercompact system is active in vitro an ... Show Experiments (1)
Testing newly discovered Biggie Phage editors in human cells
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Engineered amphiphilic peptides enable delivery of proteins and CRISPR-associated nucleases to airway epithelia.Publication - [In Vivo, In Vitro] [Delivery Systems Initiative] [Human, Mouse]PII: 10.1038/s41467-019-12922-y, PUBMED 31659165, PMC PMC6817825, DOI 10.1038/s41467-019-12922-y ABSTRACT: The delivery of biologic cargoes to airway epithelial cells is challenging due to the formidable barriers imposed by its specialized and differentiated cells. Among cargoes, recombinant proteins offer therapeutic promise but the lack of effective delivery methods limits their development. Here, we achieve protein and SpCas9 or AsCas12a ribonucleoprotein (RNP) delivery to cultured human well-differentiated airway epithelial cells and mouse lungs with engineered amphiphilic peptides. These shuttle ... Show Experiments (4)
Testing Shuttle Peptides ability to deliver GFP-NLS to airway epithelia.
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Raguram A, Liu DR, Mok BY, de Moraes MH, Zeng J, Bosch DE, Kotrys AV, Hsu F, Radey MC, Peterson SB, Mootha VK, Mougous JD
PII: 10.1038/s41586-020-2477-4, PUBMED 32641830, PMC PMC7381381, MID NIHMS1597977, DOI 10.1038/s41586-020-2477-4 ABSTRACT: Bacterial toxins represent a vast reservoir of biochemical diversity that can be repurposed for biomedical applications. Such proteins include a group of predicted interbacterial toxins of the deaminase superfamily, members of which have found application in gene-editing techniques1,2. Because previously described cytidine deaminases operate on single-stranded nucleic acids3, their use in base editing requires the unwinding of double-stranded DNA (dsDNA)-for example by a CRISPR-Cas9 system. Base ... |
CHANGE-seq reveals genetic and epigenetic effects on CRISPR-Cas9 genome-wide activity.Publication - [In Vitro] [Biological Systems] [Human]PII: 10.1038/s41587-020-0555-7, PUBMED 32541958, PMC PMC7652380, MID NIHMS1591991, DOI 10.1038/s41587-020-0555-7 ABSTRACT: Current methods can illuminate the genome-wide activity of CRISPR-Cas9 nucleases, but are not easily scalable to the throughput needed to fully understand the principles that govern Cas9 specificity. Here we describe 'circularization for high-throughput analysis of nuclease genome-wide effects by sequencing' (CHANGE-seq), a scalable, automatable tagmentation-based method for measuring the genome-wide activity of Cas9 in vitro. We applied CHANGE-seq to 110 single guide RNA targets across 13 thera ... Show Experiments (1)
A novel human T cell platform to define biological adverse effects of genome editing
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PII: 7456042, PUBMED 38033325, PMC PMC10810193, DOI 10.1093/nar/gkad1125 ABSTRACT: Guide RNAs offer programmability for CRISPR-Cas9 genome editing but also add challenges for delivery. Chemical modification, which has been key to the success of oligonucleotide therapeutics, can enhance the stability, distribution, cellular uptake, and safety of nucleic acids. Previously, we engineered heavily and fully modified SpyCas9 crRNA and tracrRNA, which showed enhanced stability and retained activity when delivered to cultured cells in the form of the ribonucleoprotein complex. In this ... |
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Tabebordbar M, Zhu K, Cheng JKW, Chew WL, Widrick JJ, Yan WX, Maesner C, Wu EY, Xiao R, Ran FA, Cong L, Zhang F, Vandenberghe LH, Church GM, Wagers AJ
PUBMED: 26721686, PMC PMC4924477, MID NIHMS791917, DOI 10.1126/science.aad5177 ABSTRACT: Frame-disrupting mutations in the DMD gene, encoding dystrophin, compromise myofiber integrity and drive muscle deterioration in Duchenne muscular dystrophy (DMD). Removing one or more exons from the mutated transcript can produce an in-frame mRNA and a truncated, but still functional, protein. In this study, we developed and tested a direct gene-editing approach to induce exon deletion and recover dystrophin expression in the mdx mouse model of DMD. Delivery by adeno-associated virus (AAV) of c ... |
6 results for search term 'crispr' in category Publication
| Type | Subtype | Name | Description | Source | View Associated.. |
|---|---|---|---|---|---|
| CRISPR-CasĪ¦ from huge phages is a hypercompact genome editor. | CRISPR-Cas systems are found widely in prokaryotes, where they provide adaptive immunity against virus infection and plasmid transformation. We describe a minimal functional CRISPR-Cas system, comprising a single ~70-kilodalton protein, CasĪ¦, and a CRISPR array, encoded exclusively in the genomes of huge bacteriophages. CasĪ¦ uses a single active site for both CRISPR RNA (crRNA) processing and crRNA-guided DNA cutting to target foreign nucleic acids. This hypercompact system is active in vitro and in human and plant cells with expanded target recognition capabilities relative to other CRISPR-Cas proteins. Useful for genome editing and DNA detection but with a molecular weight half that of Cas9 and Cas12a genome-editing enzymes, CasĪ¦ offers advantages for cellular delivery that expand the genome editing toolbox. |
Show Experiments (1)
Testing newly discovered Biggie Phage editors in human cells
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| Engineered amphiphilic peptides enable delivery of proteins and CRISPR-associated nucleases to airway epithelia. | The delivery of biologic cargoes to airway epithelial cells is challenging due to the formidable barriers imposed by its specialized and differentiated cells. Among cargoes, recombinant proteins offer therapeutic promise but the lack of effective delivery methods limits their development. Here, we achieve protein and SpCas9 or AsCas12a ribonucleoprotein (RNP) delivery to cultured human well-differentiated airway epithelial cells and mouse lungs with engineered amphiphilic peptides. These shuttle peptides, non-covalently combined with GFP protein or CRISPR-associated nuclease (Cas) RNP, allow rapid entry into cultured human ciliated and non-ciliated epithelial cells and mouse airway epithelia. Instillation of shuttle peptides combined with SpCas9 or AsCas12a RNP achieves editing of loxP sites in airway epithelia of ROSAmT/mG mice. We observe no evidence of short-term toxicity with a widespread distribution restricted to the respiratory tract. This peptide-based technology advances potential therapeutic avenues for protein and Cas RNP delivery to refractory airway epithelial cells. |
Show Experiments (4)
Testing Shuttle Peptides ability to deliver GFP-NLS to airway epithelia.
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| A bacterial cytidine deaminase toxin enables CRISPR-free mitochondrial base editing. | Bacterial toxins represent a vast reservoir of biochemical diversity that can be repurposed for biomedical applications. Such proteins include a group of predicted interbacterial toxins of the deaminase superfamily, members of which have found application in gene-editing techniques1,2. Because previously described cytidine deaminases operate on single-stranded nucleic acids3, their use in base editing requires the unwinding of double-stranded DNA (dsDNA)-for example by a CRISPR-Cas9 system. Base editing within mitochondrial DNA (mtDNA), however, has thus far been hindered by challenges associated with the delivery of guide RNA into the mitochondria4. As a consequence, manipulation of mtDNA to date has been limited to the targeted destruction of the mitochondrialĀ genome by designer nucleases9,10.Here we describe an interbacterial toxin, which we name DddA, that catalyses the deamination of cytidines within dsDNA. We engineered split-DddA halves that are non-toxic and inactive until brought together on target DNA by adjacently bound programmable DNA-binding proteins. Fusions of the split-DddA halves, transcription activator-like effector array proteins, and a uracil glycosylase inhibitor resulted in RNA-free DddA-derived cytosine base editors (DdCBEs) that catalyse Cā¢G-to-Tā¢A conversions in human mtDNA with high target specificity and product purity. We used DdCBEs to model a disease-associated mtDNA mutation in human cells, resulting in changes in respiration rates and oxidative phosphorylation. CRISPR-free DdCBEs enable the precise manipulation of mtDNA, rather than the elimination of mtDNA copies that results from its cleavage by targeted nucleases, with broad implications for the study and potential treatment of mitochondrial disorders. | ||||
| CHANGE-seq reveals genetic and epigenetic effects on CRISPR-Cas9 genome-wide activity. | Current methods can illuminate the genome-wide activity of CRISPR-Cas9 nucleases, but are not easily scalable to the throughput needed to fully understand the principles that govern Cas9 specificity. Here we describe 'circularization for high-throughput analysis of nuclease genome-wide effects by sequencing' (CHANGE-seq), a scalable, automatable tagmentation-based method for measuring the genome-wide activity of Cas9 in vitro. We applied CHANGE-seq to 110 single guide RNA targets across 13 therapeutically relevant loci in human primary T cells and identified 201,934 off-target sites, enabling the training of a machine learning model to predict off-target activity. Comparing matched genome-wide off-target, chromatin modification and accessibility, and transcriptional data, we found that cellular off-target activity was two to four times more likely to occur near active promoters, enhancers and transcribed regions. Finally, CHANGE-seq analysis of six targets across eight individual genomes revealed that human single-nucleotide variation had significant effects on activity at ~15.2% of off-target sites analyzed. CHANGE-seq is a simplified, sensitive and scalable approach to understanding the specificity of genome editors. |
Show Experiments (1)
A novel human T cell platform to define biological adverse effects of genome editing
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| Self-delivering, chemically modified CRISPR RNAs for AAV co-delivery and genome editing in vivo. | Guide RNAs offer programmability for CRISPR-Cas9 genome editing but also add challenges for delivery. Chemical modification, which has been key to the success of oligonucleotide therapeutics, can enhance the stability, distribution, cellular uptake, and safety of nucleic acids. Previously, we engineered heavily and fully modified SpyCas9 crRNA and tracrRNA, which showed enhanced stability and retained activity when delivered to cultured cells in the form of the ribonucleoprotein complex. In this study, we report that a short, fully stabilized oligonucleotide (a 'protecting oligo'), which can be displaced by tracrRNA annealing, can significantly enhance the potency and stability of a heavily modified crRNA. Furthermore, protecting oligos allow various bioconjugates to be appended, thereby improving cellular uptake and biodistribution of crRNA in vivo. Finally, we achieved in vivo genome editing in adult mouse liver and central nervous system via co-delivery of unformulated, chemically modified crRNAs with protecting oligos and AAV vectors that express tracrRNA and either SpyCas9 or a base editor derivative. Our proof-of-concept establishment of AAV/crRNA co-delivery offers a route towards transient editing activity, target multiplexing, guide redosing, and vector inactivation. | ||||
| In vivo gene editing in dystrophic mouse muscle and muscle stem cells. | Frame-disrupting mutations in the DMD gene, encoding dystrophin, compromise myofiber integrity and drive muscle deterioration in Duchenne muscular dystrophy (DMD). Removing one or more exons from the mutated transcript can produce an in-frame mRNA and a truncated, but still functional, protein. In this study, we developed and tested a direct gene-editing approach to induce exon deletion and recover dystrophin expression in the mdx mouse model of DMD. Delivery by adeno-associated virus (AAV) of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 endonucleases coupled with paired guide RNAs flanking the mutated Dmd exon23 resulted in excision of intervening DNA and restored the Dmd reading frame in myofibers, cardiomyocytes, and muscle stem cells after local or systemic delivery. AAV-Dmd CRISPR treatment partially recovered muscle functional deficiencies and generated a pool of endogenously corrected myogenic precursors in mdx mouse muscle. |