Gene editing can be used to overcome allo-recognition, which otherwise limits allogeneic T cell therapies. Initial proof-of-concept applications have included generation of such "universal" T cells expressing chimeric antigen receptors (CARs) against CD19 target antigens combined with transient expression of DNA-targeting nucleases to disrupt the T cell receptor alpha constant chain (TRAC). Although relatively efficient, transgene expression and editing effects were unlinked, yields variable, and resulting T cell populations heterogeneous, complicating dosing strategies. We describe a self-inactivating lentiviral "terminal" vector platform coupling CAR expression with CRISPR/Cas9 effects through incorporation of an sgRNA element into the Delta U3 3' long terminal repeat (LTR). Following reverse transcription and duplication of the hybrid Delta U3-sgRNA, delivery of Cas9 mRNA resulted in targeted TRAC locus cleavage and allowed the enrichment of highly homogeneous (> 96%) CAR(+) (> 99%) TCR- populations by automated magnetic separation. Molecular analyses, including NGS, WGS, and Digenome-seq, verified on-target specificity with no evidence of predicted off-target events. Robust anti-leukemic effects were demonstrated in humanized immunodeficient mice and were sustained longer than by conventional CAR(+)TCR(+) T cells. Terminal-TRAC (TT) CAR T cells offer the possibility of a pre-manufactured, non-HLA-matched CAR cell therapy and will be evaluated in phase 1 trials against B cell malignancies shortly.

BACKGROUND:Guide Picker ( https://www.deskgen.com/guide-picker/ ) serves as a meta tool for designing CRISPR experiments by presenting ten different guide RNA scoring functions in one simple graphical interface. It allows investigators to simultaneously visualize and sort through every guide targeting the protein-coding regions of any mouse or human gene.RESULTS:Utilizing a multidimensional graphical display featuring two plots and four axes, Guide Picker can analyze all guides while filtering based on four different criteria at a time. Guide Picker further facilitates the CRISPR design process by using pre-computed scores for all guides, thereby offering rapid guide RNA generation and selection.CONCLUSIONS:The ease-of-use of Guide Picker complements CRISPR itself, matching a powerful and modular biological system with a flexible online web tool that can be used in a variety of genome editing experimental contexts.

CRISPR (clustered regularly interspaced short palindromic repeats) has emerged as one of the premiere biological tools of the century. Even more so than older genome editing techniques such as TALENs and ZFNs, CRISPR provides speed and ease-of-use heretofore unheard of in agriculture, the environment and human health. The ability to map the function of virtually every component of the genome in a scalable, multiplexed manner is unprecedented. Once those regions have been explored, CRISPR also presents an opportunity to take advantage of endogenous cellular repair pathways to change and precisely edit the genome [1-3]. In the case of human health, CRISPR operates as both a tool of discovery and a solution to fundamental problems behind disease and undesirable mutations.

Desktop Genetics is a bioinformatics company building a gene-editing platform for personalized medicine. The company works with scientists around the world to design and execute state-of-the-art clustered regularly interspaced short palindromic repeats (CRISPR) experiments. Desktop Genetics feeds the lessons learned about experimental intent, single-guide RNA design and data from international genomics projects into a novel CRISPR artificial intelligence system. We believe that machine learning techniques can transform this information into a cognitive therapeutic development tool that will revolutionize medicine.