Genetic Engineering Publications - GEG Tech top picks

Researchers have reported promising results in a Phase I/II trial involving 37 patients with relapsed or refractory B-cell malignancies who were treated with a cord blood-derived natural killer (NK) chimeric antigen receptor (CAR), a cell therapy targeting CD19. Results showed an overall response (OR) rate of 48.6% 100 days after treatment, with one-year progression-free survival (PFS) and overall survival (OS) rates of 32% and 68%, respectively. The trial reported an excellent safety profile, with no cases of cytokine release syndrome (CRS), neurotoxicity or graft-versus-host disease. Another key finding of the trial was the importance of allogeneic cord blood donor selection criteria in the manufacture of CAR NK cells. Cord blood units cryopreserved within 24 hours of collection and those with a low content of nucleated red blood cells were associated with significantly better results. CAR NK cells generated from these units resulted in a one-year PFS rate of 69% and an OS rate of 94%, compared with 5% and 48%, respectively, for units with higher nucleated red cell content or longer collection to cryopreservation times. 

Here, the scientists examined the piggyBac (PB) transposon as an alternative vehicle to deliver a guide RNA (gRNA) library for in vivo screening. Through hydrodynamic tail vein injections, they delivered a PB-CRISPR library into mouse liver. Rapid tumor formation could be observed in less than 2 mo. By sequencing analysis of PB-mediated gRNA insertions, they identified corresponding genes mediating tumorigenesis. Their results demonstrate that PB is a simple and nonviral choice for efficient in vivo delivery of CRISPR libraries for phenotype-driven screens.

In this work, the authors show that by using an optimized formula of newly developed lipid-like nanoparticles (LLNs), they are able to effectively deliver Cas9 mRNA and single-guide RNA (sgRNA) to the liver and achieve in vivo targeting of HBV DNA and the proprotein convertase subtilisin/kexin type 9 (pcsk9) gene, a therapeutic target for treating hypercholesterolemia. To the best of our knowledge, this is the first report on non-viral delivery of CRISPR/Cas9 system components (mRNA + sgRNA) in adult animals.