Project description:Compact and versatile CRISPR-Cas systems will enable genome engineering applications through high-efficiency delivery in a wide variety of contexts. Here we create an efficient miniature Cas system (CasMINI) engineered from the type V-F Cas12f (Cas14) system by guide RNA and protein engineering, which is less than half the size of currently used CRISPR systems (Cas9 or Cas12a). We demonstrate that CasMINI can drive high levels of gene activation (up to thousands-fold increases), while the natural Cas12f system fails to function in mammalian cells. We show that the CasMINI system has comparable activities to Cas12a for gene activation, is highly specific, and allows for robust base editing and gene editing. We expect that CasMINI can be broadly useful for cell engineering and gene therapy applications ex vivo and in vivo.
Project description:Utilising adeno-associated virus (AAV) to deliver CRISPR/Cas has enhanced the generation of knock-out mice, but single-AAV delivery of Cas and homology-directed-repair (HDR) templates in livestock remains a challenge. Here, we introduce all-in-one AAV vectors containing shortened IscB#, the progenitor of Cas9, along with either miniature ωRNA#, or ωRNA# with a large HDR-template. Encouragingly, we efficiently generated knock-out and knock-in cattle and mice by infecting zygotes with AAV::IscB#/ωRNA#-HDR without costly micromanipulators.
Project description:Utilising adeno-associated virus (AAV) to deliver CRISPR/Cas has enhanced the generation of knock-out mice, but single-AAV delivery of Cas and homology-directed-repair (HDR) templates in livestock remains a challenge. Here, we introduce all-in-one AAV vectors containing shortened IscB#, the progenitor of Cas9, along with either miniature ωRNA#, or ωRNA# with a large HDR-template. Encouragingly, we efficiently generated knock-out and knock-in cattle and mice by infecting zygotes with AAV::IscB#/ωRNA#-HDR without costly micromanipulators.
Project description:The therapeutic application of base editors is currently limited by their large sizes, which are often beyond the packaging capabilities of adeno-associated viral (AAV) vectors. Despite recent progress in mega genome mining that has identified a diverse array of compact CRISPR proteins (e.g. Cas12f, TnpB, and IscB), the resulting miniature base editors are often exhibited reduced activities and a limited targeting scope, leaving a broad spectrum of disease-relevant genetic variants inaccessible. In this study, we have developed a platform, designated as Zinc Finger Proteins (ZFP)-enhanced miniature base editor (zmBE), which integrates programmable DNA-binding domains to enhance the efficiency and expand targeting scope of miniature base editors, including those based on Un1Cas12f1 and OgeuIscB. Utilizing protein language model (PLM) for the design of ZFPs further simplified development and optimization of zmBEs tailored to a specific target. Leveraging these methodologies, we engineered a zmBE that effectively induced the SMN2 exon 7 A6>G conversion and restored SMN2 exon 7 inclusion. Our study thus provides a versatile platform for developing miniature base editors for in vivo therapeutic applications.
2025-04-18 | GSE294498 | GEO
Project description:Engineering Miniature CRISPR-Cas Un1Cas12f1 for Efficient Base Editing
| PRJNA1022844 | ENA
Project description:Assessing and engineering the IscB-omegaRNA system for programmed genome editing
| PRJNA983934 | ENA
Project description:Engineering IscB to develop highly efficient minisize editing tools in mammalian cells and embryos
Project description:CRISPR-Cas9 delivery by AAV holds promise for gene therapy but faces critical barriers due to its potential immunogenicity and limited payload capacity. Here, we demonstrate genome engineering in postnatal mice using AAV-split-Cas9, a multi-functional platform customizable for genome-editing, transcriptional regulation, and other previously impracticable AAV-CRISPR-Cas9 applications. We identify crucial parameters that impact efficacy and clinical translation of our platform, including viral biodistribution, editing efficiencies in various organs, antigenicity, immunological reactions, and physiological outcomes. These results reveal that AAV-CRISPR-Cas9 evokes host responses with distinct cellular and molecular signatures, but unlike alternative delivery methods, does not induce detectable cellular damage in vivo. Our study provides a foundation for developing effective genome therapeutics mRNA-Seq from muscles (9 samples; 3 mice x 3 conditions) and lymph nodes (9 samples; 3 mice x 3 conditions).
Project description:Simple and efficient delivery of CRISPR genome editing systems in primary cells remains a major challenge. Here, we describe an engineered Peptide-Assisted Genome Editing (PAGE) CRISPR-Cas system for rapid and robust editing of primary cells. PAGE couples a cell-penetrating Cas protein with a cell-penetrating endosomal escape peptide in a 30-minute incubation that yields up to ~98% editing efficiency in primary human and mouse T cells. PAGE provides a broadly generalizable platform for next generation genome engineering in primary cells. CITATION INFORMATION: Zhang Zhen, Baxter Amy E, Ren Diqiu, Qin Kunhua, Chen Zeyu, Collins Sierra M., Huang Hua, Komar Chad A., Bailer Peter F., Parker Jared B., Blobel Gerd A., Kohli Rahul M., Wherry E. John*, Berger Shelley,*, and Shi Junwei*. Peptide-assisted genome editing permits efficient CRISPR engineering of primary T cells.