CMN Weekly (25 February 2022) - Your Weekly CRISPR Medicine News

Top picks

• How to protect the first ‘CRISPR babies’ prompts ethical debate. Two prominent bioethicists in China are calling on the government to set up a research centre dedicated to ensuring the well-being of the so-called CRISPR babies. Scientists have welcomed the discussion, but many are concerned that the approach would lead to unnecessary surveillance of the children. Read both sides of the story in this Nature article published today.
• Sickle cell: ‘The revolutionary gene-editing treatment that gave me new life’. This BBC piece tells the remarkable story of Jimi Olaghere, one of the sickle cell disease (SCD) patients whose own blood stem cells were CRISPR-edited ex vivo as part of Vertex Pharmaceuticals Phase 2/3 clinical trial for autologous CRISPR-edited SCD therapy. For a complete overview on gene-edited SCD trials, see our recent trial roundup here.

Research

• In an article published in Molecular Cell yesterday, researchers in Germany report the application of cell-free transcription-translation (TXTL) systems to accelerate the characterisation of multi-subunit CRISPR effectors and transposons. They demonstrate that numerous DNA constructs can be combined in one TXTL reaction to yield defined biomolecular readouts in hours. Using the setup, the team was able to elucidate targeting rules for I-B and I-F CRISPR transposons using only DNA-binding components, and they hope that this new workflow will facilitate the study and exploitation of the broad and largely uptapped repertoire of CRISPR-Cas systems and transposons.
• Scientists from multiple institutions in the U.S. have combined prime editing with Bxb1 serine integrase in a new system called PASTE (Programmable Addition via Site-specific Targeting Elements), which can seamlessly incorporate transgenes as big as 36 kb without the need for double-stranded DNA breaks. The approach has so far been tested in human primary human hepatocytes as well as T cells, and the findings were shared earlier this week on the pre-print server bioRxiv.
• Researchers in China have carried out a systematic investigation of the effects of multiple SV40 nuclear localisation signal (NLS) fusion on the genome-editing activity of purified SpCas9. The SV40 T antigen is commonly fused to Cas9-encoding genes to direct the intracellular Cas9 proteins to cell nuclei, and while the addition of multiple SV40 NLS fusions has been demonstrated to improve targeting efficiency, the exact relationship between NLS fusion and intracellular Cas9 activity has not been fully understood. The new findings, which shed light on this relationship, were published in Bioengineering this week.
• In an article published in Nature Protocols earlier this week, a team of researchers in the U.S. and Japan provide a detailed technical pipeline and protocol for using the CRISPR-Cas9 genome-editing system to knock out a gene of interest specifically in human intestinal tissue-derived organoids by lentiviral transduction and single-cell cloning. Such organoids are used as powerful ex vivo models for gastrointestinal research, and the authors discuss several ways in which the new protocol can be applied to generate knockin or conditional knockout organoid lines to investigate the function of essential genes in many biological processes.
• Researchers in Wales adapt the Adenovirus (Ad) vector with zero cloning steps (AdZ) to enable high-throughput cloning of sequences for CRISPR-Cas9 editing, even in hard to transfect cells. Vectors were optimised to ensure efficient cloning and high editing efficiency using spCas9 and sgRNA sequences in a single vector. The vectors were further engineered at the spCas9 sequence to match that of SniperCas9, which has reduced off-target activity but maintains on-target efficiency, and by applying modifications to the sgRNA sequence that significantly enhance editing efficiency. The findings were published yesterday in Human Gene Therapy.

Industry

• Intellia Therapeutics enters lease agreement to build a new 140,000-square-foot manufacturing facility in Waltham, Massachusetts, to support the manufacturing of key components for its CRISPR-based investigational therapies.
• Intellia Therapeutics announces fourth quarter and full-year 2021 financial results and highlights recent company progress.
• Gracell Biotechnologies will present multiple advancements of its TruUCAR allogeneic CAR-T platform at the upcoming American Association for Cancer Research Annual Meeting 2022. The updates include early results of a first-in-human clinical study on GC502 in relapsed or refractory B- cell acute lymphoblastic leukaemia patients. GC502 is a CD19/CD7 dual-targeting CAR T cell therapy currently under development for multiple indications. The company will also present data on another clinical candidate, GC027, which is an allogeneic CAR-T therapy designed to target CD7 for the treatment of adults with T-cell lymphoblastic leukaemia.
• Allogene Therapeutics reports fourth quarter and full-year 2021 financial results and provides business update.
• Poseida Therapeutics hosted its 2^nd Annual Virtual R&D Day this week, where it highlighted novel pre-clinical and clinical pipeline assets and latest technology innovations. The presentations covered updates on the company's unqiue site-specific transposon-based DNA delivery approch as well as their gene-editing capabilities. A full overview of the day can be found here. You can read more about Poseida's unique approach in our interview with then CEO Eric Ostertag in 2021.
• Editas Medicine announces fourth quarter and full-year 2021 results and business updates.

Reviews and research highlights

• CRISPR in cancer biology and therapy. This new review examines the progress made within the development of CRISPR systems as a tool to study cancer, and how these systems are now being adapted to improve diagnosis and treatment.

• This week, The CRISPR Journal published a special collection of articles on the theme of “CRISPR's Path to the Clinic to mark the journal's 5^th year of publishing. The collection includes articles about the application of CRISPR in disease modelling, therapies, potential drawbacks and optimisation of current CRISPR-Cas technologies, as well as novel genome-editing tools. You can find the collection here.

• A research highlight published in Nature Reviews Genetics this week highlights two recent studies published in Nature Biotechnology by Katrekar et al. and Yi et al. describe the engineering of stable gRNAs that enable more precise and efficient RNA editing than what was possible with previously available gRNA-directed endogenous adenosine deaminases acting on RNA (ADAR) to perform precise adenosine-to-inosine (guanosine) edits.

Podcasts and webinars

• Virtual Event: CRISPR Quest. Last summer, Intellia Therapeutics reported the first data showing that CRISPR could be used in vivo to combat a disease — in this case, the rare nerve disease hereditary transthyretin (TTR) amyloidosis. In CRISPR Quest, Intellia's CEO joins STAT news to discuss next steps for this study. Watch the recording here.
• Incorporating CRISPR into omics studies: what the future holds. A free webinar hosted by Cell Press covering how integration of single cell RNA-sequencing with CRISPR-based screening has led to more sophisticated, high-throughput functional genomics approaches, such as CROP-seq, TAP-seq and Perturb-CITE-seq. The webinar is scheduled for 15^th March 2022,. See here for details and sign-up.
• CRISPR without the cut: CRISPRa/i for modulating gene expression. This free Science webinar scheduled for 2^nd March 2022 will cover how CRISPR modulation (CRISPRmod) differs from CRISPR-Cas9 gene editing, the basics of CRISPRa and CRISPRi methodology and their key applications. Details and sign-up here.

News from CRISPR Medicine News

• Don't miss our CMN special, where we speak with Bradley Ringeisen, Executive Director of the Innovative Genomics Institute, to mark the 10-year anniversary of CRISPR. He reflects on a phenomenal decade of CRISPR therapy, and shares his perspectives on what the next decade has in store, and it’s not all about medicine.
• This week, we introduced our CMN disease overview, which will provide information on all the diseases that are targeted by gene-editing therapies involving CRISPR, prime editors, base editors, ZFNs, TALENs, Cas-CLOVER, MegaTAL and MegaNucleases.
• CARBON (CRISPR AgroBio) published its first newsletter this week. CARBON is a spin-off of CRISPR Medicine News, that will bring you all the latest about CRISPR in the AgroBio field. Sign up to the CARBON newsletter here.