Project description:To search for host factors regulating Zika virus infection, we performed a genome-wide loss-of-function CRISPR/Cas9 screen in haploid human ESCs. The regulators were identified by the quantification of enrichment of their mutant clones within a pooled loss-of-function library upon Zika virus infection.
Project description:Genome-wide CRISPR-Cas9 knockout screen using TKOv1 sgRNA library was performed in isogenic RBM10-proficient and RBM10-deficient HCC827 cells.
Project description:Provided data came from a detailed study on Nicotiana benthamiana 16c plants where we use Tobacco Rattle Virus (TRV) as a molecular switch to change the chromatin state of a reporter gene (P35S::GFP) from an actively transcribed to a transcriptionally silenced state. Our approach enables us to interrogate different chromatin states of the same locus with the same set of CRISPR/Cas9 genome editing reagents and systematically describe the effect of chromatin state on the frequency and type of mutations induced at various Cas9 targets in a huge set of independently edited cells.
Project description:Identifying putative transcription factor target genes by combining CRISPR/Cas9-based transcriptional activation with RNAseq in Drosophila S2R+ cells. This study focuses on the transcription factors Twist and Snail, singly and together. RNA from Drosophila cells following CRISPR/Cas9-based activation of Twist, Snail, or Twist and Snail together, compared with non-targeting sgRNA. Two biological replicates for each experiment
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:The CRISPR-Cas9 system enables efficient sequence-specific mutagenesis for creating germline mutants of model organisms. Key constraints in vivo remain the expression and delivery of active Cas9-guideRNA ribonucleoprotein complexes (RNPs) with minimal toxicity, variable mutagenesis efficiencies depending on targeting sequence, and high mutation mosaicism. Here, we established in vitro-assembled, fluorescent Cas9-sgRNA RNPs in stabilizing salt solution to achieve maximal mutagenesis efficiency in zebrafish embryos. Sequence analysis of targeted loci in individual embryos reveals highly efficient bi-allelic mutagenesis that reaches saturation at several tested gene loci. Such virtually complete mutagenesis reveals preliminary loss-of-function phenotypes for candidate genes in somatic mutant embryos for subsequent generation of stable germline mutants. We further show efficient targeting of functional non-coding elements in gene-regulatory regions using saturating mutagenesis towards uncovering functional control elements in transgenic reporters and endogenous genes. Our results suggest that in vitro assembled, fluorescent Cas9-sgRNA RNPs provide a rapid reverse-genetics tool for direct and scalable loss-of-function studies beyond zebrafish applications.
Project description:By a robust unbiased ChIP-seq approach, we demonstrated that CRISPR/Cas9 had crRNA-specific off-target binding activities in human genome. However, most of those binding off-targets could not be efficiently cleaved both in vivo and in vitro which suggested the cleavage off-target activity of CRISPR/Cas9 in human genome is very limited. We provided a valuable tool to further investigate the molecular mechanism of CRISPR/Cas9 and to optimize its in vivo targeting sgRNA binding sites were identified with ChipSeq by using GFP antibody (there are 2 replicates for egfa-t1 sgRNA,emx1 sgRNA and control without sgRNA in Hek293T cells, one egfa-t1 sgRNA,emx1 sgRNA and control without sgRNA in HeLaS3 cells)
Project description:we developed an in vivo CRISPR-Cas9 genome editing system that targets tumor-associated macrophages (TAMs) via bacterial protoplast-derived nanovesicles (NVs) decorated with a pH-responsive PEG conjugated polymer and galactosamine-conjugated ligand
Project description:Integration of the HIV-1 provirus in the host genome ensures a persistent supply of latently infected cells. This latent reservoir is recalcitrant to antiretroviral therapy (ART) making lifelong treatment the only option for patients. The â??shock and killâ?? strategy aims to eradicate latent HIV by reactivating proviral gene expression followed by ART treatment. Gene specific transcriptional activation can be achieved using the RNA-guided CRISPR-Cas9 system comprising small guide RNAs (sgRNAs) with a nuclease deficient Cas9 mutant (dCas9) fused to the VP64 transactivation domain (dCas9-VP64).  We engineered this system to target 23 sites within the LTR promoter of HIV-1 and identified a â??hotspotâ?? for activation. We studied the functionality of activating sgRNAs to transcriptionally modulate the latent proviral genome across multiple different in vitro latency cell models including several J-Lat, ACH2 J1.1 and the CEM T cell model comprising a single clonal population of integrated mCherry-IRES-Tat from a full-length HIV LTR (LChIT). While we observed variable responses of latent cell models to well-characterized chemical stimuli, we detected consistent efficient activation of latent virus mediated by activator sgRNAs. In addition, transcriptome analysis of chemically treated cells revealed massive non-specific gene dysregulation whereas by comparison, dCas9-VP64/sgRNAs induced specific activation of the integrated provirus. In conclusion, we show the potential for CRISPR-mediated gene activation systems to provide enhanced efficiency and specificity in a targeted latency reactivation strategy. This represents a promising approach to a â??functional cureâ?? of HIV/AIDS. Three experimental conditions (sgRNA control, TNF treated and sgRNA against the LTR of HIV-1) were analyzed in triplicate using two sequencing lanes