Project description:We explored whether the targeting of crRNAs affected the host cell gene expression. To do this, we used a type LNP, termed a lipitoid, to transiently transfect human A549 lung carcinoma cells with the Cas13d mRNA and in vitro synthesized crRNA(s). At 48 hpi, we isolated cellular RNA and performed whole-cell RNA sequencing (RNA-seq). We observed high reproducibility between biological replicates. We examined the off-target effects of viral-targeting crRNA for SARS-CoV-2 or 229E as well as the NT crRNA by comparing their transcriptome profiles to that of cells expressing Cas13d alone, and we saw highly similar gene expression profiles. Furthermore, co-delivery of Cas13d and two targeting crRNAs showed a very similar transcriptome profile to that of the Cas13d alone. These data suggest that Cas13d and antiviral crRNAs are highly specific, with a minimal impact on host cell transcriptomes.
Project description:CRISPR-Cas immune systems function to defend prokaryotes against potentially harmful mobile genetic elements including viruses and plasmids. The multiple CRISPR-Cas systems (Types I, II, III) each recognize and target destruction of foreign invader nucleic acids via structurally and functionally diverse effector complexes (crRNPs). CRISPR-Cas effector complexes are comprised of CRISPR RNAs (crRNAs) that contain sequences homologous to the invading nucleic acids and Cas proteins specific to each immune system type. We have previously characterized a crRNP in Pyrococcus furiosus (Pfu) that contains Cmr proteins (Type III-B) associated with one of two primary size forms of crRNAs and functions through homology-dependent cleavage of target RNAs. In the current study, we have isolated and characterized two additional native Pfu CRISPR-Cas complexes containing either Csa (Type I-A) or Cst (Type I-G) proteins and distinct profiles of associated crRNAs. For each complex, the Cas proteins were identified by tandem mass spectrometry and immunoblotting and the crRNAs by RNA deep sequencing and Northern blot analysis. The crRNAs associated with both the Csa and Cst complexes originate from each of seven total CRISPR loci and contain identical 5’ ends (8-nt CRISPR RNA repeat-derived 5’ tag sequences) but heterogeneous 3’ ends (containing variable amounts of downstream repeat sequences). These crRNA forms are distinct from Cmr-associated crRNAs, indicating different 3’ end processing pathways following primary cleavage of common pre-crRNAs. We predict that the newly identified Pfu Type I-A (Csa) and Type I-G (Cst)-containing crRNPs, like other previously characterized Type I CRISPR-Cas effector complexes, each function by carrying out crRNA-guided DNA targeting of invading mobile genetic elements. Taken together, our in-depth characterization of the three isolated native complexes provides clear evidence for three compositionally distinct crRNPs containing either Cmr, Csa, or Cst Cas proteins that together make up an impressive arsenal of CRISPR-Cas defense for a single organism. 4 Samples: Protein-associated small RNAs
Project description:CRISPR-Cas immune systems function to defend prokaryotes against potentially harmful mobile genetic elements including viruses and plasmids. The multiple CRISPR-Cas systems (Types I, II, III) each recognize and target destruction of foreign invader nucleic acids via structurally and functionally diverse effector complexes (crRNPs). CRISPR-Cas effector complexes are comprised of CRISPR RNAs (crRNAs) that contain sequences homologous to the invading nucleic acids and Cas proteins specific to each immune system type. We have previously characterized a crRNP in Pyrococcus furiosus (Pfu) that contains Cmr proteins (Type III-B) associated with one of two primary size forms of crRNAs and functions through homology-dependent cleavage of target RNAs. In the current study, we have isolated and characterized two additional native Pfu CRISPR-Cas complexes containing either Csa (Type I-A) or Cst (Type I-G) proteins and distinct profiles of associated crRNAs. For each complex, the Cas proteins were identified by tandem mass spectrometry and immunoblotting and the crRNAs by RNA deep sequencing and Northern blot analysis. The crRNAs associated with both the Csa and Cst complexes originate from each of seven total CRISPR loci and contain identical 5’ ends (8-nt CRISPR RNA repeat-derived 5’ tag sequences) but heterogeneous 3’ ends (containing variable amounts of downstream repeat sequences). These crRNA forms are distinct from Cmr-associated crRNAs, indicating different 3’ end processing pathways following primary cleavage of common pre-crRNAs. We predict that the newly identified Pfu Type I-A (Csa) and Type I-G (Cst)-containing crRNPs, like other previously characterized Type I CRISPR-Cas effector complexes, each function by carrying out crRNA-guided DNA targeting of invading mobile genetic elements. Taken together, our in-depth characterization of the three isolated native complexes provides clear evidence for three compositionally distinct crRNPs containing either Cmr, Csa, or Cst Cas proteins that together make up an impressive arsenal of CRISPR-Cas defense for a single organism.
Project description:To determine whether target genes were specifically knocked down by RfxCas13d in N2a cells, we performed RNA-seq to compare the differentially expressed genes between cells transfected with targeting crRNAs and non-targeting crRNA.
Project description:To determine what effect the collateral activity of RfxCas13d has on cells, a HEK293T cell line stably expressing RfxCas13d (HEK293T-RfxCas13d) was constructed and then transfected with plasmids encoding target gene and corresponding crRNAs. After 24 hours of transfection, cells were collected and extracted for total RNA. Then, we performed RNA-seq to compare the differentially expressed genes between cells transfected with targeting crRNAs and non-targeting crRNA.
Project description:‘Sing With Us’ choirs are an initiative established in Wales by Tenovus Cancer Care to provide social support and improve mental wellbeing amongst those affected by cancer, whether patients, carers or staff. Research has already demonstrated that these choirs can reduce depression and anxiety amongst participants and improve social support networks and quality of life as well as preliminary evidence that they can reduce levels of stress hormones and improve immune function. The aim of this study is to establish more about the psychological benefits of regular choir singing and explore whether the biological changes noted in pilot studies can be sustained over time. This could identify whether choirs have the potential to optimise health in people affected by cancer, helping to put patients in the best position to receive treatment or maintain remission and supporting those who care for someone with cancer, whether professionally or informally.