Genetic Engineering Publications - GEG Tech top picks

The race to the clinic is reviving for a ready-made alternative to autologous CAR-T cell therapy, even as concerns about chromosomal abnormalities persist. The Advanced Regenerative Medicine Therapy designation, which makes the therapy eligible for accelerated approval, will also help remove a veil that has hung over standard CAR-T cell therapies since October, when the FDA put all trials of competitor Allogene Therapeutics on hold following the detection of a chromosomal abnormality in a patient who received ALLO-501A in a Phase 2 trial. The FDA's green light for CRISPR Therapeutics dispels broader concerns that the agency views this type of genotoxic safety event as an intractable problem for the entire class of allogeneic CAR-T therapies. Today, many companies are eliminating loci associated with the MHC-I to avoid host T cell recognition of transplanted CAR-T cells. Companies also equip their T cells with a variety of safety switches and performance enhancers.

However, as the complexity of the assembly increases, the risk of off-target effects also increases. This may be important from a safety perspective, given that most cancers lack unique antigens. Achieving rapid remission and re-dosing if necessary, can minimize the toxic effects that CAR-T cells can have on healthy tissues expressing the targeted antigen.

In this work, the authors  assembled 12 transcription activator-like effector nucleases (TALENs) and five guide RNAs (gRNAs) for CRISPR system to knock out endogenous TCR expression. Using nuclease-expressing plasmid DNA, they achieved up to 19.9% and 12.2% knockout of TCR expression in primary T cells with CRISPR/Cas9 and TALENs, respectively. In contrast, delivery of TALEN mRNA by electroporation resulted in high viability and TCR knockout efficiencies of up to 78.8% for the TCR α chain and 81.2% for the β chain on day 6 after electroporation. 

Researchers have harnessed the CRISPR-Cas9 technology to correct mutations in the blood stem cells of patients with a rare immunodeficiency disorder; the engineered cells successfully engrafted in mice for up to five months.

Herein, the authors summarize recent advances that have been made on non-viral delivery of genome-editing nucleases. In particular, they focus on non-viral delivery of Cas9/sgRNA ribonucleoproteins for genome editing. In addition, the future direction for developing non-viral delivery of programmable nucleases for genome editing is discussed.

A novel CRISPR–Cas9-based gene editing approach for Huntington disease (HD) can inactivate the HD-associated mutant HTT allele without affecting the normal allele. The technique prevented expression of the mutated huntingtin protein in several cell lines.

In the review, the authors provide a perspective on the power of CRISPR-based forward and reverse genetics tools in human genetics and discuss its applications using some disease examples.

In this work, the authors generated universal CAR19 (UCART19) T cells by lentiviral transduction of non–human leukocyte antigen–matched donor cells and simultaneous transcription activator-like effector nuclease (TALEN)–mediated gene editing of T cell receptor α chain and CD52 gene loci. Two infants with relapsed refractory CD19+ B cell acute lymphoblastic leukemia received lymphodepleting chemotherapy and anti-CD52 serotherapy, followed by a single-dose infusion of UCART19 cells. Molecular remissions were achieved within 28 days in both infants, and UCART19 cells persisted until conditioning ahead of successful allogeneic stem cell transplantation. This bridge-to-transplantation strategy demonstrates the therapeutic potential of gene-editing technology.

Here, the author review the development of the different classes of programmable nucleases, discuss the challenges and improvements in translating gene editing into clinical use, and give an outlook on what applications can expect to enter the clinic in the near future.

In this study, the authors show that the CRISPR/Cas9 system can restrict the JC polyomavirus (JCPyV) life cycle in cultured cells. They utilized CRISPR/Cas9 to target the noncoding control region and the late gene open reading frame of the JCPyV genome. They found significant inhibition of virus replication and viral protein expression in cells recipient of Cas9 together with JCPyV-specific single-guide RNA delivered prior to or after JCPyV infection.

Chinese scientists are on the verge of being first in the world to inject people with cells modified using the CRISPR–Cas9 gene-editing technique.

A team led by Lu You, an oncologist at Sichuan University’s West China Hospital in Chengdu, plans to start testing such cells in people with lung cancer next month. The clinical trial received ethical approval from the hospital's review board on 6 July.